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    SubjectRe: [RFC][PATCH 3/5] OMAP SSI driver code
    continuing with this patch


    On Tue, Oct 07, 2008 at 03:03:09AM +0300, Felipe Balbi wrote:
    > On Fri, Oct 03, 2008 at 02:52:28PM +0300, Carlos Chinea wrote:
    >
    > Description. This seems to repeat in all your patches, take a look at
    > linux kernel patch format: http://linux.yyz.us/patch-format.html
    >
    > > Signed-off-by: Carlos Chinea <carlos.chinea@nokia.com>
    > > ---
    > > drivers/misc/ssi/Kconfig | 11 +
    > > drivers/misc/ssi/Makefile | 7 +
    > > drivers/misc/ssi/ssi_driver.c | 513 +++++++++++++++++++++++++++++++++++++
    > > drivers/misc/ssi/ssi_driver.h | 211 +++++++++++++++
    > > drivers/misc/ssi/ssi_driver_bus.c | 192 ++++++++++++++
    > > drivers/misc/ssi/ssi_driver_dma.c | 406 +++++++++++++++++++++++++++++
    > > drivers/misc/ssi/ssi_driver_if.c | 335 ++++++++++++++++++++++++
    > > drivers/misc/ssi/ssi_driver_int.c | 232 +++++++++++++++++
    > > 8 files changed, 1907 insertions(+), 0 deletions(-)
    > > create mode 100644 drivers/misc/ssi/Kconfig
    > > create mode 100644 drivers/misc/ssi/Makefile
    > > create mode 100644 drivers/misc/ssi/ssi_driver.c
    > > create mode 100644 drivers/misc/ssi/ssi_driver.h
    > > create mode 100644 drivers/misc/ssi/ssi_driver_bus.c
    > > create mode 100644 drivers/misc/ssi/ssi_driver_dma.c
    > > create mode 100644 drivers/misc/ssi/ssi_driver_if.c
    > > create mode 100644 drivers/misc/ssi/ssi_driver_int.c
    > >
    > > diff --git a/drivers/misc/ssi/Kconfig b/drivers/misc/ssi/Kconfig
    > > new file mode 100644
    > > index 0000000..5e0842c
    > > --- /dev/null
    > > +++ b/drivers/misc/ssi/Kconfig
    > > @@ -0,0 +1,11 @@
    > > +#
    > > +# OMAP SSI HW kernel configuration
    > > +#
    > > +config OMAP_SSI
    > > + tristate "OMAP SSI hardware driver"
    > > + depends on ARCH_OMAP
    > > + default n
    > > + ---help---
    > > + If you say Y here, you will enable the OMAP SSI hardware driver.
    > > +
    > > + If unsure, say N.
    > > diff --git a/drivers/misc/ssi/Makefile b/drivers/misc/ssi/Makefile
    > > new file mode 100644
    > > index 0000000..2b74e02
    > > --- /dev/null
    > > +++ b/drivers/misc/ssi/Makefile
    > > @@ -0,0 +1,7 @@
    > > +#
    > > +# Makefile for SSI drivers
    > > +#
    > > +omap_ssi-objs := ssi_driver.o ssi_driver_dma.o ssi_driver_int.o \
    > ^ trailing whitespace
    >
    > > + ssi_driver_if.o ssi_driver_bus.o
    > > +
    > > +obj-$(CONFIG_OMAP_SSI) += omap_ssi.o
    > > diff --git a/drivers/misc/ssi/ssi_driver.c b/drivers/misc/ssi/ssi_driver.c
    > > new file mode 100644
    > > index 0000000..292e868
    > > --- /dev/null
    > > +++ b/drivers/misc/ssi/ssi_driver.c
    > > @@ -0,0 +1,513 @@
    > > +/*
    > > + * ssi_driver.c
    > > + *
    > > + * Implements SSI module interface, initialization, and PM related functions.
    > > + *
    > > + * Copyright (C) 2007-2008 Nokia Corporation. All rights reserved.
    > > + *
    > > + * Contact: Carlos Chinea <carlos.chinea@nokia.com>
    > > + *
    > > + * This program is free software; you can redistribute it and/or
    > > + * modify it under the terms of the GNU General Public License
    > > + * version 2 as published by the Free Software Foundation.
    > > + *
    > > + * This program is distributed in the hope that it will be useful, but
    > > + * WITHOUT ANY WARRANTY; without even the implied warranty of
    > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    > > + * General Public License for more details.
    > > + *
    > > + * You should have received a copy of the GNU General Public License
    > > + * along with this program; if not, write to the Free Software
    > > + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
    > > + * 02110-1301 USA
    > > + */
    > > +
    > > +#include <linux/err.h>
    > > +#include "ssi_driver.h"
    > > +
    > > +static void ssi_dev_release(struct device *dev)
    > > +{
    > > +}
    > > +
    > > +static void __init ssi_undo_reg_dev(struct platform_device *pd,
    > > + int p, int ch)
    >
    > Take a few tabs out of the second line, it'll look better.
    >
    > > +{
    > > + struct ssi_platform_data *p_data =
    >
    > normally we call it pdata, but it's your call in this case
    >
    > > + (struct ssi_platform_data *) pd->dev.platform_data;
    >
    > unnecessary cast. Remove
    >
    > > + struct ssi_port *ssi_p;
    > > + int port;
    > > + int channel;
    > > +
    > > + for (port = p; port >= 0; port--) {
    > > + ssi_p = &p_data->ssi_ctrl->ssi_port[port];
    > > + for (channel = ch; channel >= 0 ; channel--)
    > > + device_unregister(&ssi_p->ssi_channel[channel].dev
    > > + ->device);
    >
    > This function should be unnecessary. pdata usage is wrong.
    >
    > > + }
    > > +}
    > > +
    > > +static int __init reg_ssi_dev_ch(struct platform_device *pd,
    > > + unsigned int p, unsigned int ch)
    >
    > the following should be probe().
    >
    > > +{
    > > + struct ssi_device *dev;
    > > + struct ssi_platform_data *p_data =
    > > + (struct ssi_platform_data *) pd->dev.platform_data;
    >
    > unnecessary cast, remove.
    >
    > > +
    > > + dev = kzalloc(sizeof(*dev), GFP_KERNEL);
    > > + if (!dev)
    > > + return -ENOMEM;
    > > + dev->n_ctrl = pd->id;
    > > + dev->n_p = p;
    > > + dev->n_ch = ch;
    > > + dev->ch = &p_data->ssi_ctrl->ssi_port[p].ssi_channel[ch];
    > > + p_data->ssi_ctrl->ssi_port[p].ssi_channel[ch].dev = dev;
    >
    > pdata usage is wrong. It should be used to initialize a few fields in
    > the device structure and then vanish.
    >
    > > + dev->device.bus = &ssi_bus_type;
    > > + dev->device.parent = &pd->dev;
    > > + dev->device.release = ssi_dev_release;
    > > + if (dev->n_ctrl < 0)
    > > + snprintf(dev->device.bus_id, sizeof(dev->device.bus_id),
    > > + "omap_ssi-p%u.c%u", p, ch);
    > > + else
    > > + snprintf(dev->device.bus_id, sizeof(dev->device.bus_id),
    > > + "omap_ssi%d-p%u.c%u", dev->n_ctrl, p, ch);
    > > +
    > > + return device_register(&dev->device);
    > > +}
    > > +
    > > +static int __init register_ssi_devices(struct platform_device *pd)
    > > +{
    > > + struct ssi_platform_data *p_data =
    > > + (struct ssi_platform_data *) pd->dev.platform_data;
    >
    > unnecessary cast. Remove
    >
    > > + unsigned int n_ch = 0;
    > > + int port;
    > > + int ch = 0;
    > > + int err = 0;
    > > +
    > > + for (port = 0; ((port < p_data->num_ports) && (err >= 0)); port++) {
    > > + n_ch = max(p_data->ports[port].tx_ch,
    > > + p_data->ports[port].rx_ch);
    > > + for (ch = 0; ((ch < n_ch) && (err >= 0)); ch++)
    > > + err = reg_ssi_dev_ch(pd, port, ch);
    > > + }
    > > +
    > > + if (err < 0) {
    > > + port--;
    > > + ch--;
    > > + dev_err(&pd->dev, "Error registering ssi device channel "
    > > + "p%d-c%d : %d\n", port, ch, err);
    > > + if ((port == 0) && (ch == 0))
    > > + return err;
    > > + else if ((port > 0) && (ch == 0))
    > > + ch = n_ch;
    > > + ssi_undo_reg_dev(pd, port, ch);
    > > + }
    > > + return err;
    > > +}
    > > +
    > > +static int __init ssi_softreset(struct ssi_dev *ssi_ctrl)
    > > +{
    > > + int ind = 0;
    > > + void __iomem *base = ssi_ctrl->base;
    > > + u32 status;
    > > +
    > > + ssi_outl_or(SSI_SOFTRESET, base, SSI_SYS_SYSCONFIG_REG);
    > > +
    > > + status = ssi_inl(base, SSI_SYS_SYSSTATUS_REG);
    > > + while ((!(status & SSI_RESETDONE)) && (ind < SSI_RESETDONE_RETRIES)) {
    > > + set_current_state(TASK_UNINTERRUPTIBLE);
    > > + schedule_timeout(msecs_to_jiffies(SSI_RESETDONE_TIMEOUT));
    > > + status = ssi_inl(base, SSI_SYS_SYSSTATUS_REG);
    > > + ind++;
    > > + }
    > > +
    > > + if (ind >= SSI_RESETDONE_RETRIES)
    > > + return -EIO;
    > > +
    > > + /* Reseting GDD */
    > > + ssi_outl_or(SSI_SWRESET, base, SSI_GDD_GRST_REG);
    > > +
    > > + return 0;
    > > +}
    > > +
    > > +static void __init set_ssi_ports_default(
    > > + struct platform_device *pd)
    > > +{
    > > + struct ssi_port_pd *cfg = NULL;
    > > + struct ssi_platform_data *p_data =
    > > + (struct ssi_platform_data *) pd->dev.platform_data;
    > > + unsigned int port = 0;
    > > + void __iomem *base = p_data->ssi_ctrl->base;
    >
    > is this really a virtual address?? then can you use
    > __raw_{read,write}[blw]() and drop ssi-specific read/write functions?
    >
    > btw, the base address shouldn't come via pdata, it should come via
    > struct resource and get ioremap:ed in the driver. Recently we fixed all
    > the physical/virtual address mess and if we accept this it'll lead to
    > similar issues. Please fix.
    >
    > > +
    > > + for (port = 1; port <= p_data->num_ports; port++) {
    > > + cfg = &p_data->ports[port - 1];
    > > + ssi_outl(cfg->tx_mode, base, SSI_SST_MODE_REG(port));
    > > + ssi_outl(cfg->tx_frame_size, base, SSI_SST_FRAMESIZE_REG(port));
    > > + ssi_outl(cfg->divisor, base, SSI_SST_DIVISOR_REG(port));
    > > + ssi_outl(cfg->tx_ch, base, SSI_SST_CHANNELS_REG(port));
    > > + ssi_outl(cfg->arb_mode, base, SSI_SST_ARBMODE_REG(port));
    > > +
    > > + ssi_outl(cfg->rx_mode, base, SSI_SSR_MODE_REG(port));
    > > + ssi_outl(cfg->rx_frame_size, base, SSI_SSR_FRAMESIZE_REG(port));
    > > + ssi_outl(cfg->rx_ch, base, SSI_SSR_CHANNELS_REG(port));
    > > + ssi_outl(cfg->timeout, base, SSI_SSR_TIMEOUT_REG(port));
    > > + }
    > > +}
    > > +
    > > +static int __init ssi_port_channels_init(
    > > + struct platform_device *pd, unsigned int lport)
    > > +{
    > > + struct ssi_platform_data *p_data =
    > > + (struct ssi_platform_data *) pd->dev.platform_data;
    > > + struct ssi_channel *ch;
    > > + struct ssi_port *port;
    > > + unsigned int n_ch;
    > > + unsigned int ch_i;
    > > +
    > > + n_ch = max(p_data->ports[lport].tx_ch, p_data->ports[lport].rx_ch);
    > > + port = &p_data->ssi_ctrl->ssi_port[lport];
    > > + for (ch_i = 0; ch_i < n_ch; ch_i++) {
    > > + ch = &port->ssi_channel[ch_i];
    > > + ch->channel_number = ch_i;
    > > + ch->flags = 0;
    > > + ch->ssi_port = port;
    > > + ch->read_data.addr = NULL;
    > > + ch->read_data.size = 0;
    > > + ch->read_data.lch = -1;
    > > + ch->write_data.addr = NULL;
    > > + ch->write_data.size = 0;
    > > + ch->write_data.lch = -1;
    > > + spin_lock_init(&ch->ssi_ch_lock);
    > > + }
    > > +
    > > + return 0;
    > > +}
    > > +
    > > +static int __init ssi_ports_init(struct platform_device *pd)
    > > +{
    > > + struct ssi_platform_data *p_data =
    > > + (struct ssi_platform_data *) pd->dev.platform_data;
    >
    > unnecessary cast. Remove
    >
    > > + struct ssi_port *ssi_p = NULL;
    > > + unsigned int port = 0;
    > > + unsigned int err = 0;
    > > + unsigned int n_ports;
    > > +
    > > + n_ports = min(p_data->num_ports, (u8)SSI_MAX_PORTS);
    > > +
    > > + for (port = 0; ((port < n_ports) && (err >= 0)); port++) {
    > > + ssi_p = &p_data->ssi_ctrl->ssi_port[port];
    > > + ssi_p->port_number = port + 1;
    > > + ssi_p->ssi_controller = p_data->ssi_ctrl;
    > > + ssi_p->max_ch = max(p_data->ports[port].tx_ch,
    > > + p_data->ports[port].rx_ch);
    > > + ssi_p->max_ch = min(ssi_p->max_ch, (u8)SSI_PORT_MAX_CH);
    > > + ssi_p->n_irq = p_data->ports[port].n_irq;
    > > + ssi_p->irq = 0;
    > > + spin_lock_init(&ssi_p->lock);
    > > + err = ssi_port_channels_init(pd, port);
    > > + }
    > > +
    > > + return 0;
    > > +}
    > > +
    > > +static int __init ssi_controller_init(struct platform_device *pd)
    > > +{
    > > + struct ssi_platform_data *p_data =
    > > + (struct ssi_platform_data *) pd->dev.platform_data;
    > > + struct ssi_dev *ssi_ctrl = p_data->ssi_ctrl;
    > > + int err;
    > > +
    > > + ssi_ctrl->id = pd->id;
    > > + ssi_ctrl->max_p = p_data->num_ports;
    >
    > in the header file you have a define for the max_ports and here you use
    > platform_data to initialize it. Quite weird. Where are you using that
    > define ?
    >
    > > + ssi_ctrl->pdev = pd;
    >
    > do not save the entire pdev pointer, save only the dev pointer use
    > platform_set_drvdata(pdev, ssi_ctrl);
    >
    > > + spin_lock_init(&ssi_ctrl->lock);
    > > + ssi_ctrl->ssi_clk = clk_get(&pd->dev, p_data->clk_name);
    >
    > please don't.
    >
    > > + if (IS_ERR(ssi_ctrl->ssi_clk)) {
    > > + dev_err(&pd->dev, "Unable to get SSI clocks");
    > > + return PTR_ERR(ssi_ctrl->ssi_clk);
    > > + }
    > > +
    > > + err = ssi_ports_init(pd);
    > > + if (err < 0) {
    > > + dev_err(&pd->dev, "Error on ssi_controller initialization");
    > > + clk_put(ssi_ctrl->ssi_clk);
    > > + return -EBUSY;
    > > + }
    > > +
    > > + return 0;
    > > +}
    > > +
    > > +static void ssi_controller_exit(struct platform_device *pd)
    > > +{
    > > + struct ssi_platform_data *p_data =
    > > + (struct ssi_platform_data *) pd->dev.platform_data;
    >
    > unnecessary cast, remove.
    >
    > > + struct ssi_dev *ssi_ctrl = p_data->ssi_ctrl;
    > > +
    > > + p_data->ssi_ctrl = NULL;
    > > + ssi_ctrl->pdev = NULL;
    > > + clk_put(ssi_ctrl->ssi_clk);
    > > +
    >
    > unnecessary extra white line, remove.
    >
    > > +}
    > > +
    > > +static int __init request_ssi_irqs(struct platform_device *pd)
    > > +{
    > > + struct ssi_platform_data *p_data = pd->dev.platform_data;
    > > + struct ssi_dev *ssi_ctrl = p_data->ssi_ctrl;
    > > + struct ssi_port *ssi_p;
    > > + struct resource *mpu_irq;
    >
    > unnecessary if it's only to get the irq.
    >
    > > + int i;
    > > + int j;
    > > + int err = 0;
    > > +
    > > + for (i = 0; ((i < p_data->num_ports) && (!err)); i++) {
    > > + mpu_irq = platform_get_resource(pd, IORESOURCE_IRQ, i*2);
    >
    > no
    >
    > > + if (!mpu_irq) {
    > > + dev_err(&pd->dev, "SSI misses info for MPU IRQ"
    > > + " on port %d", i + 1);
    > > + err = -ENODEV;
    >
    > use a goto to create a nice error path, then you remove this else below.
    >
    > > + } else {
    > > + ssi_p = &ssi_ctrl->ssi_port[i];
    > > + ssi_p->n_irq = 0; /* We only use one irq line */
    > > + ssi_p->irq = mpu_irq->start;
    >
    > ssi_p->irq = platform_get_irq(pdev, 0);
    > also gets rid of the unnecessary mpu_irq.
    >
    > > + tasklet_init(&ssi_p->ssi_tasklet,
    > > + do_ssi_tasklet, (unsigned long)ssi_p);
    > > + err = request_irq(mpu_irq->start, ssi_mpu_handler,
    > > + IRQF_DISABLED, mpu_irq->name, ssi_p);
    > > + if (err < 0) {
    > > + dev_err(&pd->dev, "FAILED request IRQ (%d)",
    > > + mpu_irq->start);
    > > + err = -EBUSY;
    > > + }
    > > + }
    > > + }
    > > +
    > > + if (err < 0) {
    > > + /* Let's free the reserved resources if there are any errors */
    > > + for (j = 0; (j > (i-1)); j++) {
    > > + printk(KERN_DEBUG LOG_NAME "Free resources on port %d",
    > > + j+1);
    > > + ssi_p = &ssi_ctrl->ssi_port[i];
    > > + tasklet_disable(&ssi_p->ssi_tasklet);
    > > + free_irq(ssi_p->irq, ssi_p);
    > > + }
    > > + }
    > > +
    > > + return err;
    > > +}
    > > +
    > > +static int __init request_ssi_gdd_irq(struct platform_device *pd)
    > > +{
    > > + struct ssi_platform_data *p_data = pd->dev.platform_data;
    > > + struct ssi_dev *ssi_ctrl = p_data->ssi_ctrl;
    > > + struct resource *gdd_irq;
    >
    > no
    >
    > > + int err = 0;
    > > +
    > > + gdd_irq = platform_get_resource(pd, IORESOURCE_IRQ, 4);
    >
    > no
    >
    > > + if (!gdd_irq) {
    > > + dev_err(&pd->dev, "SSI device has no info about GDD IRQ");
    > > + return -ENODEV;
    > > + }
    > > +
    > > + ssi_ctrl->gdd_irq = gdd_irq->start;
    >
    > hell no. Use platform_get_irq() like I said before.
    >
    > > + err = request_irq(gdd_irq->start, ssi_gdd_mpu_handler,
    > > + IRQF_DISABLED, gdd_irq->name, ssi_ctrl);
    > > + if (err < 0) {
    > > + dev_err(&pd->dev, "FAILED to request IRQ NUMBER (%d)",
    > > + gdd_irq->start);
    > > + return -EBUSY;
    > > + }
    > > + tasklet_init(&ssi_ctrl->ssi_gdd_tasklet, do_ssi_gdd_tasklet,
    > > + (unsigned long)ssi_ctrl);
    > > +
    > > + return err;
    > > +}
    > > +
    > > +static void free_ssi_irqs(struct ssi_dev *ssi_ctrl)
    > > +{
    > > + struct ssi_port *ssi_p;
    > > + int i;
    > > +
    > > + for (i = 0; (i < ssi_ctrl->max_p); i++) {
    > > + ssi_p = &ssi_ctrl->ssi_port[i];
    > > + tasklet_disable(&ssi_p->ssi_tasklet);
    > > + free_irq(ssi_p->irq, ssi_p);
    > > + }
    > > +}
    > > +
    > > +static void free_ssi_gdd_irq(struct ssi_dev *ssi_ctrl)
    > > +{
    > > + tasklet_disable(&ssi_ctrl->ssi_gdd_tasklet);
    > > + free_irq(ssi_ctrl->gdd_irq, ssi_ctrl);
    > > +}
    > > +
    > > +static int __init ssi_probe(struct platform_device *pd)
    > > +{
    > > + struct resource *mem, *ioarea;
    > > + struct ssi_dev *ssi_ctrl = NULL;
    > > + struct ssi_platform_data *p_data = NULL;
    > > + u32 revision = 0;
    > > + int err = 0;
    > > +
    > > +
    > > + if ((pd == NULL) || (pd->dev.platform_data == NULL)) {
    > > + pr_err(LOG_NAME "No device/platform_data found on "
    > > + "ssi device\n");
    > > + return -ENODEV;
    > > + }
    >
    > aff... pd will never be NULL if this driver is probing. I'd rather:
    >
    > struct ssi_platform_data *pdata = pd->dev.platform_data;
    >
    > if (!pdata) {
    > error messages goes here
    > }
    >
    > > +
    > > + ssi_ctrl = kzalloc(sizeof(*ssi_ctrl), GFP_KERNEL);
    > > + if (ssi_ctrl == NULL) {
    > > + dev_err(&pd->dev, "Could not allocate memory for"
    > > + " struct ssi_dev\n");
    > > + return -ENOMEM;
    > > + }
    > > +
    > > + p_data = (struct ssi_platform_data *) pd->dev.platform_data;
    >
    > no cast needed.
    >
    > > + p_data->ssi_ctrl = ssi_ctrl;
    >
    > hell no. platform_set_drvdata(pd, ssi_ctrl);
    >
    > > +
    > > + mem = platform_get_resource(pd, IORESOURCE_MEM, 0);
    > > + if (!mem) {
    > > + dev_err(&pd->dev, "SSI device does not have "
    > > + "SSI IO memory region information\n");
    > > + err = -ENODEV;
    > > + goto rback5;
    > > + }
    > > +
    > > + err = ssi_controller_init(pd);
    > > + if (err < 0) {
    > > + dev_err(&pd->dev, "Could not initialize ssi controller:"
    > > + " %d\n", err);
    > > + goto rback5;
    > > + }
    > > +
    > > + ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
    > > + pd->dev.bus_id);
    > > + if (!ioarea) {
    > > + dev_err(&pd->dev, "Unable to request SSI IO memory "
    > > + "region\n");
    > > + err = -EBUSY;
    > > + goto rollback4;
    > > + }
    > > +
    > > + ssi_ctrl->base = (void __iomem *)mem->start;
    >
    > afff... this is terrible. Use ioremap();
    >
    > > +
    > > + clk_enable(ssi_ctrl->ssi_clk);
    > > +
    > > + err = request_ssi_irqs(pd);
    > > + if (err < 0)
    > > + goto rollback1;
    > > +
    > > + err = request_ssi_gdd_irq(pd);
    > > + if (err < 0)
    > > + goto rollback2;
    > > +
    > > + err = ssi_softreset(ssi_ctrl);
    > > + if (err < 0)
    > > + goto rollback3;
    > > +
    > > + /* Set default PM settings */
    > > + ssi_outl((SSI_AUTOIDLE | SSI_SIDLEMODE_SMART | SSI_MIDLEMODE_SMART),
    > > + ssi_ctrl->base, SSI_SYS_SYSCONFIG_REG);
    > > + ssi_outl(SSI_CLK_AUTOGATING_ON, ssi_ctrl->base, SSI_GDD_GCR_REG);
    > > +
    > > + set_ssi_ports_default(pd);
    > > +
    > > + /* Gather info from registers for the driver.(REVISION) */
    > > + revision = ssi_inl(ssi_ctrl->base, SSI_SYS_REVISION_REG);
    > > + dev_info(&pd->dev, "SSI Hardware REVISION %d.%d\n",
    > > + (revision & SSI_REV_MAJOR) >> 4, (revision & SSI_REV_MINOR));
    > > +
    > > + err = register_ssi_devices(pd);
    > > + if (err < 0)
    > > + goto rollback3;
    > > +
    > > + clk_disable(ssi_ctrl->ssi_clk);
    > > +
    > > + return err;
    > > +
    > > +rollback3:
    > > + free_ssi_gdd_irq(ssi_ctrl);
    > > +rollback2:
    > > + free_ssi_irqs(ssi_ctrl);
    > > +rollback1:
    > add iounmap() here
    > > + release_mem_region(mem->start, mem->end - mem->start + 1);
    > > + clk_disable(ssi_ctrl->ssi_clk);
    > > +rollback4:
    > > + ssi_controller_exit(pd);
    > > +rback5:
    > > + kfree(ssi_ctrl);
    > > + return err;
    > > +}
    > > +
    > > +static void __exit close_all_ch(struct ssi_dev *ssi_ctrl)
    > > +{
    > > + struct ssi_port *ssi_p;
    > > + unsigned int port;
    > > + unsigned int ch;
    > > +
    > > + for (port = 0; port < ssi_ctrl->max_p; port++) {
    > > + ssi_p = &ssi_ctrl->ssi_port[port];
    > > + for (ch = 0; ch < ssi_p->max_ch; ch++)
    > > + ssi_close(ssi_p->ssi_channel[ch].dev);
    > > + }
    > > +}
    > > +
    > > +static int __exit ssi_remove(struct platform_device *pd)
    > > +{
    > > + struct resource *mem;
    > > + struct ssi_platform_data *p_data =
    > > + (struct ssi_platform_data *) pd->dev.platform_data;
    > > + struct ssi_dev *ssi_ctrl = p_data->ssi_ctrl;
    >
    > This should ssi_ctrl = platform_get_drvdata(pd);
    >
    > > +
    > > + close_all_ch(ssi_ctrl);
    > > + free_ssi_gdd_irq(ssi_ctrl);
    > > + free_ssi_irqs(ssi_ctrl);
    > > + mem = platform_get_resource(pd, IORESOURCE_MEM, 0);
    > > + if (mem)
    > > + release_mem_region(mem->start, mem->end - mem->start + 1);
    >
    > when you add proper ioremap(), add iounmap here.
    >
    > > + ssi_controller_exit(pd);
    > > + kfree(ssi_ctrl);
    > > +
    > > + return 0;
    > > +}
    > > +
    > > +static struct platform_driver ssi_pdriver = {
    > > + .probe = ssi_probe,
    > > + .remove = __exit_p(ssi_remove),
    > > + .driver = {
    > > + .name = "omap_ssi",
    > > + .owner = THIS_MODULE,
    > > + }
    > > +};
    > > +
    > > +static int __init ssi_driver_init(void)
    > > +{
    > > + int err = 0;
    > > +
    > > + pr_info("SSI DRIVER Version " SSI_DRIVER_VERSION "\n");
    > > +
    > > + ssi_bus_init();
    > > + err = platform_driver_probe(&ssi_pdriver, ssi_probe);
    > > + if (err < 0) {
    > > + pr_err(LOG_NAME "Platform DRIVER register FAILED: %d\n", err);
    > > + ssi_bus_exit();
    > > + return err;
    > > + }
    > > +
    > > + return 0;
    >
    > return platform_driver_register(&ssi_pdriver);
    > should be enough.
    >
    > > +}
    > > +
    > > +static void __exit ssi_driver_exit(void)
    > > +{
    > > + ssi_bus_exit();
    > > + platform_driver_unregister(&ssi_pdriver);
    > > +
    > > + pr_info("SSI DRIVER removed\n");
    > > +}
    > > +
    > > +module_init(ssi_driver_init);
    > > +module_exit(ssi_driver_exit);
    > > +
    > > +MODULE_ALIAS("platform:omap_ssi");
    > > +MODULE_AUTHOR(SSI_DRIVER_AUTHOR);
    > > +MODULE_DESCRIPTION(SSI_DRIVER_DESC);
    > > +MODULE_LICENSE("GPL");
    > > diff --git a/drivers/misc/ssi/ssi_driver.h b/drivers/misc/ssi/ssi_driver.h
    > > new file mode 100644
    > > index 0000000..3c6d849
    > > --- /dev/null
    > > +++ b/drivers/misc/ssi/ssi_driver.h
    > > @@ -0,0 +1,211 @@
    > > +/*
    > > + * ssi_driver.h
    > > + *
    > > + * Header file for the SSI driver low level interface.
    > > + *
    > > + * Copyright (C) 2007-2008 Nokia Corporation. All rights reserved.
    > > + *
    > > + * Contact: Carlos Chinea <carlos.chinea@nokia.com>
    > > + *
    > > + * This program is free software; you can redistribute it and/or
    > > + * modify it under the terms of the GNU General Public License
    > > + * version 2 as published by the Free Software Foundation.
    > > + *
    > > + * This program is distributed in the hope that it will be useful, but
    > > + * WITHOUT ANY WARRANTY; without even the implied warranty of
    > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    > > + * General Public License for more details.
    > > + *
    > > + * You should have received a copy of the GNU General Public License
    > > + * along with this program; if not, write to the Free Software
    > > + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
    > > + * 02110-1301 USA
    > > + */
    > > +
    > > +#ifndef __SSI_DRIVER_H__
    > > +#define __SSI_DRIVER_H__
    > > +
    > > +#include <linux/module.h>
    > > +#include <linux/init.h>
    > > +#include <linux/clk.h>
    > > +#include <linux/ioport.h>
    > > +#include <linux/interrupt.h>
    > > +#include <linux/irq.h>
    > > +#include <linux/spinlock.h>
    > > +#include <linux/io.h>
    > > +#include <linux/platform_device.h>
    > > +#include <linux/gpio.h>
    > > +
    > > +#include <mach/ssi/ssi_reg_common.h>
    > > +#include <mach/ssi/ssi_sys_reg.h>
    > > +#include <mach/ssi/ssi_ssr_reg.h>
    > > +#include <mach/ssi/ssi_sst_reg.h>
    > > +#include <mach/ssi/ssi_gdd_reg.h>
    > > +
    > > +#include <linux/ssi_driver_if.h>
    > > +
    > > +#define SSI_DRIVER_VERSION "1.1-rc2"
    > > +#define SSI_DRIVER_AUTHOR "Carlos Chinea / Nokia"
    > > +#define SSI_DRIVER_DESC "Synchronous Serial Interface Driver"
    > > +#define SSI_DRIVER_LINCESE "GPL"
    > > +#define SSI_DRIVER_NAME "ssi_driver"
    > > +
    > > +#define SSI_DEVICE_NAME "ssi_device"
    >
    > these should be in the C-file. Nobody needs to access them
    >
    > > +
    > > +/* 10 ms */
    > > +#define SSI_RESETDONE_TIMEOUT 10
    > > +/* Let's retry 20 times.=>20x10 ms=200 ms */
    > > +#define SSI_RESETDONE_RETRIES 20
    > > +
    > > +/* Channel states */
    > > +#define SSI_CH_OPEN 0x01
    > > +
    > > +/*
    > > + * The number of channels to use by the driver in the ports, or the highest
    > > + * port channel number (+1) used. (MAX:8)
    > > + */
    > > +#define SSI_PORT_MAX_CH 4
    > > +/* Number of logical channel in GDD */
    > > +#define SSI_NUM_LCH 8
    > > +
    > > +#define LOG_NAME "OMAP SSI: "
    > > +#define SSI_PREFIX "ssi:"
    > > +
    > > +/*
    > > + * Callbacks use by the SSI upper layer (SSI protocol) to receive data
    > > + * from the port channels.
    > > + */
    > > +struct ssi_channel_ops {
    > > + void (*write_done) (struct ssi_device *dev);
    > > + void (*read_done) (struct ssi_device *dev);
    > > +};
    > > +
    > > +struct ssi_data {
    > > + /* Pointer to the data to be sent/received */
    > > + u32 *addr;
    > > + /*
    > > + * Number of words to be sent or space reserved for data to be
    > > + * received.
    > > + */
    > > + unsigned int size;
    > > + /* Holds GDD logical channed number */
    > > + int lch;
    > > +};
    > > +
    > > +struct ssi_channel {
    > > + struct ssi_channel_ops ops;
    > > + struct ssi_data read_data;
    > > + struct ssi_data write_data;
    > > + struct ssi_port *ssi_port;
    > > + u8 flags;
    > > + u8 channel_number;
    > > + spinlock_t ssi_ch_lock;
    > > + struct ssi_device *dev;
    > > + void *priv;
    > > +};
    > > +
    > > +/* Holds information related to SSI port */
    > > +struct ssi_port {
    > > + struct ssi_channel ssi_channel[SSI_PORT_MAX_CH];
    > > + struct ssi_dev *ssi_controller;
    > > + u8 port_number;
    > > + u8 max_ch;
    > > + u8 n_irq; /* IRQ0 or IRQ1 */
    > > + int irq /* Actual IRQ number */;
    > > + spinlock_t lock;
    > > + struct tasklet_struct ssi_tasklet;
    > > +};
    > > +
    > > +/*
    > > + * Struct definition to hold information about the clocks, ssi controller
    > > + * and the ssi ports.
    > > + */
    > > +struct ssi_dev {
    > > + /* Holds reference to PORT 1 (and PORT2 if defined) */
    > > + struct ssi_port ssi_port[SSI_MAX_PORTS];
    > > + int id;
    > > + u8 flags;
    > > + u8 max_p;
    > > + struct clk *ssi_clk;
    > > + void __iomem *base;
    > > + spinlock_t lock;
    > > + int gdd_irq;
    > > + struct tasklet_struct ssi_gdd_tasklet;
    > > + struct platform_device *pdev;
    > > +};
    > > +
    > > +/* SSI Bus */
    > > +struct ssi_port_event {
    > > + struct ssi_port *ssi_port;
    > > + unsigned int event;
    > > + void *priv;
    > > +};
    > > +extern struct bus_type ssi_bus_type;
    > > +
    > > +int ssi_port_event_handler(struct ssi_port *p, unsigned int event, void *arg);
    > > +int ssi_bus_init(void);
    > > +void ssi_bus_exit(void);
    > > +/* End SSI Bus */
    > > +
    > > +int ssi_driver_read_interrupt(struct ssi_channel *ssi_channel, u32 *data);
    > > +int ssi_driver_write_interrupt(struct ssi_channel *ssi_channel, u32 *data);
    > > +int ssi_driver_read_dma(struct ssi_channel *ssi_channel, u32 *data,
    > > + unsigned int count);
    > > +int ssi_driver_write_dma(struct ssi_channel *ssi_channel, u32 *data,
    > > + unsigned int count);
    > > +
    > > +void ssi_driver_cancel_write_interrupt(struct ssi_channel *ch);
    > > +void ssi_driver_cancel_read_interrupt(struct ssi_channel *ch);
    > > +void ssi_driver_cancel_write_dma(struct ssi_channel *ch);
    > > +void ssi_driver_cancel_read_dma(struct ssi_channel *ch);
    > > +
    > > +irqreturn_t ssi_mpu_handler(int irq, void *ssi_port);
    > > +irqreturn_t ssi_gdd_mpu_handler(int irq, void *ssi_controller);
    > > +
    > > +void do_ssi_tasklet(unsigned long ssi_port);
    > > +void do_ssi_gdd_tasklet(unsigned long device);
    > > +
    > > +static inline u32 ssi_inl(void __iomem *base, u32 offset)
    > > +{
    > > + return inl(OMAP2_IO_ADDRESS(base + offset));
    > > +}
    > > +
    > > +static inline void ssi_outl(u32 data, void __iomem *base, u32 offset)
    > > +{
    > > + outl(data, OMAP2_IO_ADDRESS(base + offset));
    > > +}
    > > +
    > > +static inline void ssi_outl_or(u32 data, void __iomem *base, u32 offset)
    > > +{
    > > + u32 tmp = ssi_inl(base, offset);
    > > + ssi_outl((tmp | data), base, offset);
    > > +}
    > > +
    > > +static inline void ssi_outl_and(u32 data, void __iomem *base, u32 offset)
    > > +{
    > > + u32 tmp = ssi_inl(base, offset);
    > > + ssi_outl((tmp & data), base, offset);
    > > +}
    > > +
    > > +static inline u16 ssi_inw(void __iomem *base, u32 offset)
    > > +{
    > > + return inw(OMAP2_IO_ADDRESS(base + offset));
    > > +}
    > > +
    > > +static inline void ssi_outw(u16 data, void __iomem *base, u32 offset)
    > > +{
    > > + outw(data, OMAP2_IO_ADDRESS(base + offset));
    > > +}
    > > +
    > > +static inline void ssi_outw_or(u16 data, void __iomem *base, u32 offset)
    > > +{
    > > + u16 tmp = ssi_inw(base, offset);
    > > + ssi_outw((tmp | data), base, offset);
    > > +}
    > > +
    > > +static inline void ssi_outw_and(u16 data, void __iomem *base, u32 offset)
    > > +{
    > > + u16 tmp = ssi_inw(base, offset);
    > > + ssi_outw((tmp & data), base, offset);
    > > +}
    > > +#endif
    > > diff --git a/drivers/misc/ssi/ssi_driver_bus.c b/drivers/misc/ssi/ssi_driver_bus.c
    > > new file mode 100644
    > > index 0000000..6a07ee0
    > > --- /dev/null
    > > +++ b/drivers/misc/ssi/ssi_driver_bus.c
    > > @@ -0,0 +1,192 @@
    > > +/*
    > > + * ssi_driver_bus.c
    > > + *
    > > + * Implements SSI bus, device and driver interface.
    > > + *
    > > + * Copyright (C) 2007-2008 Nokia Corporation. All rights reserved.
    > > + *
    > > + * Contact: Carlos Chinea <carlos.chinea@nokia.com>
    > > + *
    > > + * This program is free software; you can redistribute it and/or
    > > + * modify it under the terms of the GNU General Public License
    > > + * version 2 as published by the Free Software Foundation.
    > > + *
    > > + * This program is distributed in the hope that it will be useful, but
    > > + * WITHOUT ANY WARRANTY; without even the implied warranty of
    > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    > > + * General Public License for more details.
    > > + *
    > > + * You should have received a copy of the GNU General Public License
    > > + * along with this program; if not, write to the Free Software
    > > + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
    > > + * 02110-1301 USA
    > > + */
    > > +#include <linux/device.h>
    > > +#include "ssi_driver.h"
    > > +
    > > +/* LDM. defintions for the ssi bus, ssi device, and ssi_device driver */
    > > +struct bus_type ssi_bus_type;
    > > +
    > > +static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
    > > + char *buf)
    > > +{
    > > + return snprintf(buf, BUS_ID_SIZE + 1, "%s%s\n", SSI_PREFIX,
    > > + dev->bus_id);
    > > +}
    > > +
    > > +static struct device_attribute ssi_dev_attrs[] = {
    > > + __ATTR_RO(modalias),
    > > + __ATTR_NULL,
    > > +};
    > > +
    > > +static int ssi_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
    > > +{
    > > + add_uevent_var(env, "MODALIAS=%s%s", SSI_PREFIX, dev->bus_id);
    > > + return 0;
    > > +}
    > > +
    > > +/* NOTE: Function called in interrupt context */
    > > +static int ssi_e_handler(struct device_driver *drv, void *p_event)
    > > +{
    > > + struct ssi_port_event *event = (struct ssi_port_event *)p_event;
    > > + struct ssi_device_driver *ssi_drv = to_ssi_device_driver(drv);
    > > + struct ssi_port *p = event->ssi_port;
    > > +
    > > + BUG_ON(p_event == NULL);
    > > +
    > > + if ((ssi_drv->port_event) &&
    > > + (test_bit(event->event, &ssi_drv->event_mask)) &&
    > > + ((p->ssi_controller->id == -1) ||
    > > + (test_bit(p->ssi_controller->id, &ssi_drv->ctrl_mask))) &&
    > > + (ssi_drv->ch_mask[p->port_number - 1] != 0)) {
    > > +
    > > + (*ssi_drv->port_event)(p->ssi_controller->id, p->port_number,
    > > + event->event, event->priv);
    > > + }
    > > +
    > > + return 0;
    > > +}
    > > +
    > > +int ssi_port_event_handler(struct ssi_port *p, unsigned int event, void *arg)
    > > +{
    > > + int err = 0;
    > > + struct ssi_port_event p_ev = {
    > > + .ssi_port = p,
    > > + .event = event,
    > > + .priv = arg
    > > + };
    > > +
    > > + BUG_ON(p == NULL);
    > > +
    > > + err = bus_for_each_drv(&ssi_bus_type, NULL, &p_ev, ssi_e_handler);
    > > +
    > > + return err;
    > > +}
    > > +
    > > +static int ssi_bus_match(struct device *device, struct device_driver *driver)
    > > +{
    > > + struct ssi_device *dev = to_ssi_device(device);
    > > + struct ssi_device_driver *drv = to_ssi_device_driver(driver);
    > > +
    > > + if (!test_bit(dev->n_ctrl, &drv->ctrl_mask))
    > > + return 0;
    > > +
    > > + if (!test_bit(dev->n_ch, &drv->ch_mask[dev->n_p]))
    > > + return 0;
    > > +
    > > + return 1;
    > > +}
    > > +
    > > +int ssi_bus_unreg_dev(struct device *device, void *p)
    > > +{
    > > + device->release(device);
    > > + device_unregister(device);
    > > +
    > > + return 0;
    > > +}
    > > +
    > > +int __init ssi_bus_init(void)
    > > +{
    > > +

    remove this extra line

    > > + return bus_register(&ssi_bus_type);
    > > +

    remove this extra line

    > > +}
    > > +
    > > +void ssi_bus_exit(void)
    > > +{
    > > + bus_for_each_dev(&ssi_bus_type, NULL, NULL, ssi_bus_unreg_dev);
    > > + bus_unregister(&ssi_bus_type);
    > > +}
    > > +
    > > +static int ssi_driver_probe(struct device *dev)
    > > +{
    > > + struct ssi_device_driver *drv = to_ssi_device_driver(dev->driver);
    int ret;

    if (!drv->probe) /* note if you add MODULE_DEVICE_TABLE test here !drv->id_table */
    return -ENODEV;

    I think would be nice to save a reference of driver inside ssi_device,
    so you would:

    to_ssi_device(dev)->driver = drv;
    dev_dbg(dev, "probe\n");

    ret = driver->probe(to_ssi_device(dev));

    if (ret)
    to_ssi_device(dev)->driver = NULL

    return ret;

    > > +}
    > > +
    > > +static int ssi_driver_remove(struct device *dev)
    > > +{
    > > + struct ssi_device_driver *drv = to_ssi_device_driver(dev->driver);
    int ret;

    if (!dev->driver)
    return 0;

    drv = to_ssi_device_driver(dev->driver);
    if (drv->remove) {
    dev_dbg(dev, "remove\n");
    ret = drv->remove(to_ssi_device(dev));
    } else {
    dev->driver = NULL;
    ret = 0;
    }

    if (ret == 0)
    to_sse_device(dev)->driver = NULL;

    return ret;
    > > +}
    > > +
    > > +static int ssi_driver_suspend(struct device *dev, pm_message_t mesg)
    > > +{
    > > + struct ssi_device_driver *drv = to_ssi_device_driver(dev->driver);
    > > +
    > > + return drv->suspend(to_ssi_device(dev), mesg);
    > > +}
    > > +
    > > +static int ssi_driver_resume(struct device *dev)
    > > +{
    > > + struct ssi_device_driver *drv = to_ssi_device_driver(dev->driver);
    > > +
    > > + return drv->resume(to_ssi_device(dev));

    you need to be careful here. Try something like:

    if (!dev->driver)
    return 0;

    drv = to_ssi_device_driver(dev->driver);

    if (!drv->suspend)
    return 0;

    return driver->suspend(to_ssi_device(dev), msg);

    ditto to suspend

    > > +}
    > > +
    > > +struct bus_type ssi_bus_type = {
    > > + .name = "ssi",
    > > + .dev_attrs = ssi_dev_attrs,
    > > + .match = ssi_bus_match,
    > > + .uevent = ssi_bus_uevent,
    >
    > tabify these
    >
    > .name = "ssi",
    > .dev_attrs = ssi_dev_attrs,
    > .match = ssi_bus_match,
    > .uevent = ssi_bus_uevent,

    add suspend, resume, probe and remove to ssi_bus_type and remove what
    you have in register_ssi_driver.

    > > +int register_ssi_driver(struct ssi_device_driver *driver)
    > > +{
    > > + int ret = 0;
    > > +
    > > + BUG_ON(driver == NULL);
    >
    > don't bug, just return. BUG will oops the kernel. Returning would be
    > more appropriate since what needs fix is the driver trying to register
    > not the bus driver.
    >
    > > +
    > > + driver->driver.bus = &ssi_bus_type;

    --- remove from here

    > > + if (driver->probe)
    > > + driver->driver.probe = ssi_driver_probe;
    > > + if (driver->remove)
    > > + driver->driver.remove = ssi_driver_remove;
    > > + if (driver->suspend)
    > > + driver->driver.suspend = ssi_driver_suspend;
    > > + if (driver->resume)
    > > + driver->driver.resume = ssi_driver_resume;
    > > +

    --- to here.

    > > + ret = driver_register(&driver->driver);

    would be nice to get a success message if ret == 0:

    if (ret == 0)
    pr_debug("ssi: driver %s registered\n", driver->driver.name);

    > > +
    > > + return ret;
    > > +}
    > > +EXPORT_SYMBOL(register_ssi_driver);
    > > +
    > > +/**
    > > + * unregister_ssi_driver - Unregister SSI device driver
    > > + * @driver - reference to the SSI device driver.
    > > + */
    > > +void unregister_ssi_driver(struct ssi_device_driver *driver)
    > > +{
    > > + BUG_ON(driver == NULL);
    >
    > ditto.
    >
    > > +
    > > + driver_unregister(&driver->driver);

    same here:

    pr_debug("ssi: driver %s unregistered\n", driver->driver.name);

    > > +}
    > > +EXPORT_SYMBOL(unregister_ssi_driver);
    > > diff --git a/drivers/misc/ssi/ssi_driver_dma.c b/drivers/misc/ssi/ssi_driver_dma.c
    > > new file mode 100644
    > > index 0000000..2524a12
    > > --- /dev/null
    > > +++ b/drivers/misc/ssi/ssi_driver_dma.c
    > > @@ -0,0 +1,406 @@
    > > +/*
    > > + * ssi_driver_dma.c
    > > + *
    > > + * Implements SSI low level interface driver functionality with DMA support.
    > > + *
    > > + * Copyright (C) 2007-2008 Nokia Corporation. All rights reserved.
    > > + *
    > > + * Contact: Carlos Chinea <carlos.chinea@nokia.com>
    > > + *
    > > + * This program is free software; you can redistribute it and/or
    > > + * modify it under the terms of the GNU General Public License
    > > + * version 2 as published by the Free Software Foundation.
    > > + *
    > > + * This program is distributed in the hope that it will be useful, but
    > > + * WITHOUT ANY WARRANTY; without even the implied warranty of
    > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    > > + * General Public License for more details.
    > > + *
    > > + * You should have received a copy of the GNU General Public License
    > > + * along with this program; if not, write to the Free Software
    > > + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
    > > + * 02110-1301 USA
    > > + */
    > > +#include <linux/dma-mapping.h>
    > > +#include "ssi_driver.h"
    > > +
    > > +#define SSI_SYNC_WRITE 0
    > > +#define SSI_SYNC_READ 1
    > ^^ trailing whitespaces
    > > +
    the following variables and functions, etc please prepend them with ssi_
    to avoid possible namespace conflicts.

    also, fix the comment style to be kerneldoc style:

    /**
    * function name - small description
    *
    * @parameter1: small description
    * @parameter2: small description
    * @parameterN: small description
    *
    * Here you put a long description of the function
    * and what it really does. Just don't extend too much
    * and don't translate C-code into english, just give
    * information on what's the main purpose for that function
    * and anything you think is really valid to mention.
    *
    * Returns 0 on success or negative errno
    */
    of course the Returns blabla will have to change according to what the
    function really returns: channel number, port number, sync type, etc.

    > > +static unsigned char sync_table[2][2][8] = {
    > > + {
    > > + {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08},
    > > + {0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x00}
    > > + },
    > > + {
    >
    > }, { would look better
    >
    > > + {0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17},
    > > + {0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F}
    > > + }
    > > +};
    > > +
    > > +static unsigned int get_sync_type(unsigned int sync)
    > > +{
    > > + return (sync & 0x10) ? SSI_SYNC_READ : SSI_SYNC_WRITE;
    > > +}
    > > +
    > > +static unsigned int get_sync_port(unsigned int sync)
    > > +{
    > > + if (((sync >= 0x01) && (sync <= 0x08)) ||
    > > + ((sync >= 0x10) && (sync <= 0x17)))
    > > + return 1;
    > > + else if (((sync >= 0x09) && (sync <= 0x0F)) ||
    > > + ((sync >= 0x18) && (sync <= 0x1E)))
    > > + return 2;
    > > + else
    > > + return 3;

    what's the main idea here? you pass sync and it's return the port number ??
    this really looks odd. I wanna understand this better and let's try to
    find a better solution, shall we ? :-)

    > > +}
    > > +
    > > +static unsigned int get_sync_channel(unsigned int sync)
    > > +{
    > > + if ((sync == 0x00) || (sync == 0x1F))
    > > + return 8;
    > > +
    > > + if (sync & 0x10)
    > > + return (sync & 0x0F) % 8;
    > > + else
    > > + return (sync - 1) % 8;

    ditto

    > > +}
    > > +
    > > +static unsigned int get_sync(unsigned int port,
    > > + unsigned int channel, unsigned int type)
    > > +{
    > > + if ((port == 0) || (port > SSI_MAX_PORTS) ||
    > > + (channel >= SSI_PORT_MAX_CH) || (type > SSI_SYNC_READ))
    > > + return 0x00;
    > > +
    > > + return sync_table[type][port - 1][channel];

    ditto

    > > +}
    > > +
    > > +static void rst_ch_read(struct ssi_dev *ssi_ctrl,
    > > + unsigned int n_p, unsigned int n_ch)
    > > +{
    > > + struct ssi_channel *ch =
    > > + &ssi_ctrl->ssi_port[n_p - 1].ssi_channel[n_ch];
    > > +
    > > + ch->read_data.addr = NULL;
    > > + ch->read_data.size = 0;
    > > + ch->read_data.lch = -1;
    > > +}
    > > +
    > > +static void rst_ch_write(struct ssi_dev *ssi_ctrl,
    > > + unsigned int n_p, unsigned int n_ch)
    > > +{
    > > + struct ssi_channel *ch =
    > > + &ssi_ctrl->ssi_port[n_p - 1].ssi_channel[n_ch];
    > > +
    > > + ch->write_data.addr = NULL;
    > > + ch->write_data.size = 0;
    > > + ch->write_data.lch = -1;
    > > +}
    > > +
    > > +/*
    > > + * get_free_lch - Get a free GDD(DMA)logical channel
    > > + * @ssi_ctrl- SSI controller of the GDD.
    > > + *
    > > + * Needs to be called holding the gdd controller lock
    > > + */
    > > +static unsigned int get_free_lch(struct ssi_dev *ssi_ctrl)
    > > +{
    > > + unsigned int enable_reg;
    > > + unsigned int lch = 0;
    > > +
    > > + enable_reg = ssi_inl(ssi_ctrl->base, SSI_SYS_GDD_MPU_IRQ_ENABLE_REG);
    > > + while ((lch < SSI_NUM_LCH) && (enable_reg & SSI_GDD_LCH(lch)))
    > > + lch++;
    > > +
    > > + return lch;
    > > +}
    > > +
    > > +/*
    > > + * ssi_driver_write_dma - Program GDD [DMA] to write data from memory to
    > > + * the ssi channel buffer.
    > > + * @ssi_channel - pointer to the ssi_channel to write data to.
    > > + * @data - 32-bit word pointer to the data.
    > > + * @size - Number of 32bit words to be transfered.
    > > + *
    > > + * ssi_controller lock must be hold before calling this function.

    s/hold/held

    > > + */
    > > +int ssi_driver_write_dma(struct ssi_channel *ssi_channel, u32 *data,
    > > + unsigned int size)
    > > +{
    > > + struct ssi_dev *ssi_ctrl = ssi_channel->ssi_port->ssi_controller;
    > > + void __iomem *base = ssi_ctrl->base;
    > > + unsigned int port = ssi_channel->ssi_port->port_number;
    > > + unsigned int channel = ssi_channel->channel_number;
    > > + unsigned int sync;
    > > + int lch;
    > > + dma_addr_t dma_data;
    > > + u32 s_addr;
    > > + u16 tmp;
    > > +
    > > + if ((size < 1) || (data == NULL))
    > > + return -EINVAL;
    > > +
    > > + clk_enable(ssi_ctrl->ssi_clk);
    > > +
    > > + lch = get_free_lch(ssi_ctrl);
    > > + if (lch >= SSI_NUM_LCH) {
    > > + dev_err(&ssi_ctrl->pdev->dev, "No free GDD logical "
    > > + "channels.\n");
    > > + clk_disable(ssi_ctrl->ssi_clk);
    > > + return -EBUSY; /* No free GDD logical channels. */
    > > + }
    > > + /* NOTE: Gettting a free gdd logical channel and
    > > + * reserve it must be done atomicaly. */
    > > + ssi_channel->write_data.lch = lch;
    > > +
    > > + sync = get_sync(port, channel, SSI_SYNC_WRITE);
    > > + dma_data = dma_map_single(NULL, data, size * 4, DMA_TO_DEVICE);
    > > + dma_sync_single(NULL, dma_data, size * 4, DMA_TO_DEVICE);
    > > +
    > > + tmp = SSI_SRC_SINGLE_ACCESS0 |
    > > + SSI_SRC_MEMORY_PORT |
    > > + SSI_DST_SINGLE_ACCESS0 |
    > > + SSI_DST_PERIPHERAL_PORT |
    > > + SSI_DATA_TYPE_S32;
    > > + ssi_outw(tmp, base, SSI_GDD_CSDP_REG(lch));
    > > + tmp = SSI_SRC_AMODE_POSTINC | SSI_DST_AMODE_CONST | sync;
    > > + ssi_outw(tmp, base, SSI_GDD_CCR_REG(lch));
    > > + ssi_outw((SSI_BLOCK_IE | SSI_TOUT_IE), base, SSI_GDD_CICR_REG(lch));
    > > + s_addr = (u32)base + SSI_SST_BUFFER_CH_REG(port, channel);
    > > + ssi_outl(s_addr, base, SSI_GDD_CDSA_REG(lch));
    > > + ssi_outl(dma_data, base, SSI_GDD_CSSA_REG(lch));
    > > + ssi_outw(size, base, SSI_GDD_CEN_REG(lch));
    > > + ssi_outl_or(SSI_GDD_LCH(lch), base, SSI_SYS_GDD_MPU_IRQ_ENABLE_REG);
    > > + ssi_outw_or(SSI_CCR_ENABLE, base, SSI_GDD_CCR_REG(lch));

    a bit of spacing up here will increase readability.

    > > +
    > > + return 0;
    > > +}
    > > +
    > > +/*
    > > + * ssi_driver_read_dma - Program GDD [DMA] to write data to memory from
    > > + * the ssi channel buffer.
    > > + * @ssi_channel - pointer to the ssi_channel to read data from.
    > > + * @data - 32-bit word pointer where to store the incoming data.
    > > + * @size - Number of 32bit words to be transfered to the buffer.
    > > + *
    > > + * ssi_controller lock must be hold before calling this function.
    > > + */
    > > +int ssi_driver_read_dma(struct ssi_channel *ssi_channel, u32 *data,
    > > + unsigned int count)
    > > +{
    > > + struct ssi_dev *ssi_ctrl = ssi_channel->ssi_port->ssi_controller;
    > > + void __iomem *base = ssi_ctrl->base;
    > > + unsigned int port = ssi_channel->ssi_port->port_number;
    > > + unsigned int channel = ssi_channel->channel_number;
    > > + unsigned int sync;
    > > + unsigned int lch;
    > > + dma_addr_t dma_data;
    > > + u32 d_addr;
    > > + u16 tmp;
    > > +
    > > + clk_enable(ssi_ctrl->ssi_clk);
    > > + lch = get_free_lch(ssi_ctrl);
    > > + if (lch >= SSI_NUM_LCH) {
    > > + dev_err(&ssi_ctrl->pdev->dev, "No free GDD logical "
    > > + "channels.\n");
    > > + clk_disable(ssi_ctrl->ssi_clk);
    > > + return -EBUSY; /* No free GDD logical channels. */
    > > + }
    > > + /*
    > > + * NOTE: Gettting a free gdd logical channel and
    > > + * reserve it must be done atomicaly.
    > > + */
    > > + ssi_channel->read_data.lch = lch;
    > > +
    > > + sync = get_sync(port, channel, SSI_SYNC_READ);
    > > +
    > > + dma_data = dma_map_single(NULL, data, count * 4, DMA_FROM_DEVICE);
    > > +
    > > + tmp = SSI_DST_SINGLE_ACCESS0 |
    > > + SSI_DST_MEMORY_PORT |
    > > + SSI_SRC_SINGLE_ACCESS0 |
    > > + SSI_SRC_PERIPHERAL_PORT |
    > > + SSI_DATA_TYPE_S32;
    > > + ssi_outw(tmp, base, SSI_GDD_CSDP_REG(lch));
    > > + tmp = SSI_DST_AMODE_POSTINC | SSI_SRC_AMODE_CONST | sync;
    > > + ssi_outw(tmp, base, SSI_GDD_CCR_REG(lch));
    > > + ssi_outw((SSI_BLOCK_IE | SSI_TOUT_IE), base, SSI_GDD_CICR_REG(lch));
    > > + d_addr = (u32)base + SSI_SSR_BUFFER_CH_REG(port, channel);

    don't keep casting the addresses, find a better solution. If you need to
    keep casting them around between void __iomem * and some unsigned, your
    code needs attention. Ditto to all other occurrencies of this.

    > > + ssi_outl(d_addr, base, SSI_GDD_CSSA_REG(lch));
    > > + ssi_outl((u32)dma_data, base, SSI_GDD_CDSA_REG(lch));
    > > + ssi_outw(count, base, SSI_GDD_CEN_REG(lch));

    ditto.

    > > +
    > > + ssi_outl_or(SSI_GDD_LCH(lch), base, SSI_SYS_GDD_MPU_IRQ_ENABLE_REG);
    > > + ssi_outw_or(SSI_CCR_ENABLE, base, SSI_GDD_CCR_REG(lch));
    > > +
    > > + return 0;
    > > +}
    > > +
    > > +void ssi_driver_cancel_write_dma(struct ssi_channel *ssi_ch)
    > > +{
    > > + int lch = ssi_ch->write_data.lch;
    > > + unsigned int port = ssi_ch->ssi_port->port_number;
    > > + unsigned int channel = ssi_ch->channel_number;
    > > + struct ssi_dev *ssi_ctrl = ssi_ch->ssi_port->ssi_controller;
    > > + u32 ccr;
    > > +
    > > + if (lch < 0)
    > > + return;
    > > +
    > > + clk_enable(ssi_ctrl->ssi_clk);
    > > + ccr = ssi_inw(ssi_ctrl->base, SSI_GDD_CCR_REG(lch));
    > > + if (!(ccr & SSI_CCR_ENABLE)) {
    > > + dev_dbg(&ssi_ch->dev->device, LOG_NAME "Write cancel on not "
    > > + "enabled logical channel %d CCR REG 0x%08X\n", lch, ccr);
    > > + clk_disable(ssi_ctrl->ssi_clk);
    > > + return;
    > > + }
    > > +
    > > + ssi_outw_and(~SSI_CCR_ENABLE, ssi_ctrl->base, SSI_GDD_CCR_REG(lch));
    > > + ssi_outl_and(~SSI_GDD_LCH(lch), ssi_ctrl->base,
    > > + SSI_SYS_GDD_MPU_IRQ_ENABLE_REG);
    > > + ssi_outl(SSI_GDD_LCH(lch), ssi_ctrl->base,
    > > + SSI_SYS_GDD_MPU_IRQ_STATUS_REG);
    > > +
    > > + ssi_outl_and(~NOTFULL(channel), ssi_ctrl->base,
    > > + SSI_SST_BUFSTATE_REG(port));
    > > +
    > > +

    any reason why one blank line isn't enough ?

    > > + ssi_ch->write_data.addr = NULL;
    > > + ssi_ch->write_data.size = 0;
    > > + ssi_ch->write_data.lch = -1;
    > > + clk_disable(ssi_ctrl->ssi_clk);
    > > + clk_disable(ssi_ctrl->ssi_clk);

    clk_disable is duplicated.

    > > +}
    > > +
    > > +void ssi_driver_cancel_read_dma(struct ssi_channel *ssi_ch)
    > > +{
    > > + int lch = ssi_ch->read_data.lch;
    > > + struct ssi_dev *ssi_ctrl = ssi_ch->ssi_port->ssi_controller;
    > > + unsigned int port = ssi_ch->ssi_port->port_number;
    > > + unsigned int channel = ssi_ch->channel_number;
    > > + u32 reg;
    > > +
    > > + if (lch < 0)
    > > + return;
    > > +
    > > + clk_enable(ssi_ctrl->ssi_clk);
    > > + reg = ssi_inw(ssi_ctrl->base, SSI_GDD_CCR_REG(lch));
    > > + if (!(reg & SSI_CCR_ENABLE)) {
    > > + dev_dbg(&ssi_ch->dev->device, LOG_NAME "Read cancel on not "
    > > + "enable logical channel %d CCR REG 0x%08X\n", lch, reg);
    > > + clk_disable(ssi_ctrl->ssi_clk);
    > > + return;
    > > + }
    > > +
    > > + ssi_outw_and(~SSI_CCR_ENABLE, ssi_ctrl->base, SSI_GDD_CCR_REG(lch));
    > > + ssi_outl_and(~SSI_GDD_LCH(lch), ssi_ctrl->base,
    > > + SSI_SYS_GDD_MPU_IRQ_ENABLE_REG);
    > > + ssi_outl(SSI_GDD_LCH(lch), ssi_ctrl->base,
    > > + SSI_SYS_GDD_MPU_IRQ_STATUS_REG);
    > > +
    > > + ssi_outl_and(~NOTEMPTY(channel), ssi_ctrl->base,
    > > + SSI_SSR_BUFSTATE_REG(port));
    > > +
    > > + ssi_ch->read_data.addr = NULL;
    > > + ssi_ch->read_data.size = 0;
    > > + ssi_ch->read_data.lch = -1;
    > > + clk_disable(ssi_ctrl->ssi_clk);
    > > + clk_disable(ssi_ctrl->ssi_clk);

    ditto.

    > > +}
    > > +
    > > +static void dma_read_cb(struct ssi_dev *ctrl, unsigned int port,
    > > + unsigned int channel)

    take a few tabs away from the second line.

    > > +{
    > > + struct ssi_channel *ch = &ctrl->ssi_port[port - 1].ssi_channel[channel];
    > > +
    > > + ch->ops.read_done(ch->dev);
    > > +}
    > > +
    > > +static void dma_write_cb(struct ssi_dev *ctrl, unsigned int port,
    > > + unsigned int channel)

    take a few tabs away from the second line.

    > > +{
    > > + struct ssi_channel *ch = &ctrl->ssi_port[port - 1].ssi_channel[channel];
    > > +
    > > + ch->ops.write_done(ch->dev);
    > > +}
    > > +
    > > +static void do_gdd_lch(struct ssi_dev *ssi_ctrl, unsigned int gdd_lch)
    > > +{
    > > + void __iomem *base = ssi_ctrl->base;
    > > + unsigned int port;
    > > + unsigned int channel;
    > > + u32 sync;
    > > + u32 gdd_csr;
    > > + dma_addr_t dma_h;
    > > + size_t size;
    > > +
    > > + sync = ssi_inw(base, SSI_GDD_CCR_REG(gdd_lch)) & SSI_CCR_SYNC_MASK;
    > > + port = get_sync_port(sync);
    > > + channel = get_sync_channel(sync);
    > > +
    > > + spin_lock(&ssi_ctrl->lock);
    > > +
    > > + ssi_outl_and(~SSI_GDD_LCH(gdd_lch), base,
    > > + SSI_SYS_GDD_MPU_IRQ_ENABLE_REG);
    > > + gdd_csr = ssi_inw(base, SSI_GDD_CSR_REG(gdd_lch));
    > > +
    > > + if (!(gdd_csr & SSI_CSR_TOUR)) {
    > > + if (get_sync_type(sync) == SSI_SYNC_READ) {
    > > + dma_h = ssi_inl(base, SSI_GDD_CDSA_REG(gdd_lch));
    > > + size = ssi_inw(base, SSI_GDD_CEN_REG(gdd_lch)) * 4;
    > > + dma_sync_single(NULL, dma_h, size, DMA_FROM_DEVICE);
    > > + rst_ch_read(ssi_ctrl, port, channel);
    > > + spin_unlock(&ssi_ctrl->lock);
    > > + dma_read_cb(ssi_ctrl, port, channel);
    > > + } else {
    > > + rst_ch_write(ssi_ctrl, port, channel);
    > > + spin_unlock(&ssi_ctrl->lock);
    > > + dma_write_cb(ssi_ctrl, port, channel);
    > > + }
    > > + } else {
    > > + dev_err(&ssi_ctrl->pdev->dev, "Error on GDD transfer "
    > > + "on gdd channel %d port %d channel %d\n",
    > > + gdd_lch, port, channel);
    > > + spin_unlock(&ssi_ctrl->lock);
    > > + ssi_port_event_handler(&ssi_ctrl->ssi_port[port - 1],
    > > + SSI_EVENT_ERROR, NULL);
    > > + }
    > > +}
    > > +
    > > +void do_ssi_gdd_tasklet(unsigned long device)
    > > +{
    > > + struct ssi_dev *ssi_ctrl = (struct ssi_dev *)device;
    > > + void __iomem *base = ssi_ctrl->base;
    > > + unsigned int gdd_lch = 0;
    > > + u32 status_reg = 0;
    > > + u32 lch_served = 0;
    > > +
    > > + clk_enable(ssi_ctrl->ssi_clk);
    > > +
    > > + status_reg = ssi_inl(base, SSI_SYS_GDD_MPU_IRQ_STATUS_REG);
    > > +
    > > + for (gdd_lch = 0; gdd_lch < SSI_NUM_LCH; gdd_lch++) {
    > > + if (status_reg & SSI_GDD_LCH(gdd_lch)) {
    > > + do_gdd_lch(ssi_ctrl, gdd_lch);
    > > + lch_served |= SSI_GDD_LCH(gdd_lch);
    > > + clk_disable(ssi_ctrl->ssi_clk);

    clk_disable() will be called as many times as this loop executes and the
    if condition is met. Fix it.

    > > + }
    > > + }
    > > +
    > > + ssi_outl(lch_served, base, SSI_SYS_GDD_MPU_IRQ_STATUS_REG);
    > > + clk_disable(ssi_ctrl->ssi_clk);
    > > +
    > > + enable_irq(ssi_ctrl->gdd_irq);
    > > +}
    > > +
    > > +irqreturn_t ssi_gdd_mpu_handler(int irq, void *ssi_controller)
    > > +{
    > > + struct ssi_dev *ssi_ctrl = (struct ssi_dev *)ssi_controller;
    > > +
    > > + tasklet_hi_schedule(&ssi_ctrl->ssi_gdd_tasklet);
    > > + disable_irq_nosync(ssi_ctrl->gdd_irq);
    > > +
    > > + return IRQ_HANDLED;
    > > +}
    > > diff --git a/drivers/misc/ssi/ssi_driver_if.c b/drivers/misc/ssi/ssi_driver_if.c
    > > new file mode 100644
    > > index 0000000..385467e
    > > --- /dev/null
    > > +++ b/drivers/misc/ssi/ssi_driver_if.c
    > > @@ -0,0 +1,335 @@
    > > +/*
    > > + * ssi_driver_if.c
    > > + *
    > > + * Implements SSI hardware driver interfaces for the upper layers.
    > > + *
    > > + * Copyright (C) 2007-2008 Nokia Corporation. All rights reserved.
    > > + *
    > > + * Contact: Carlos Chinea <carlos.chinea@nokia.com>
    > > + *
    > > + * This program is free software; you can redistribute it and/or
    > > + * modify it under the terms of the GNU General Public License
    > > + * version 2 as published by the Free Software Foundation.
    > > + *
    > > + * This program is distributed in the hope that it will be useful, but
    > > + * WITHOUT ANY WARRANTY; without even the implied warranty of
    > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    > > + * General Public License for more details.
    > > + *
    > > + * You should have received a copy of the GNU General Public License
    > > + * along with this program; if not, write to the Free Software
    > > + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
    > > + * 02110-1301 USA
    > > + */
    > > +
    > > +#include "ssi_driver.h"
    > > +
    > > +/**
    > > + * ssi_open - open a ssi device channel.
    > > + * @dev - Reference to the ssi device channel to be openned.
    > > + *
    > > + * Returns 0 on success, -EINVAL on bad parameters, -EBUSY if is already opened.
    > > + */
    > > +int ssi_open(struct ssi_device *dev)
    > > +{
    > > + struct ssi_channel *ch;
    > > + struct ssi_port *port;
    > > + struct ssi_dev *ssi_ctrl;
    > > +
    > > + if (!dev || !dev->ch) {
    > > + pr_err(LOG_NAME "Wrong SSI device %p\n", dev);
    > > + return -EINVAL;
    > > + }
    > > +
    > > + ch = dev->ch;
    > > + if (!ch->ops.read_done || !ch->ops.write_done) {
    > > + dev_err(&dev->device, "Trying to open with no callbacks "
    > > + "registered\n");
    > > + return -EINVAL;
    > > + }
    > > + port = ch->ssi_port;
    > > + ssi_ctrl = port->ssi_controller;
    > > + spin_lock_bh(&ssi_ctrl->lock);
    > > + if (ch->flags & SSI_CH_OPEN) {
    > > + dev_err(&dev->device, "Port %d Channel %d already OPENED\n",
    > > + dev->n_p, dev->n_ch);
    > > + spin_unlock_bh(&ssi_ctrl->lock);
    > > + return -EBUSY;
    > > + }
    > > + clk_enable(ssi_ctrl->ssi_clk);
    > > + ch->flags |= SSI_CH_OPEN;
    > > + ssi_outl_or(SSI_ERROROCCURED | SSI_BREAKDETECTED, ssi_ctrl->base,
    > > + SSI_SYS_MPU_ENABLE_REG(port->port_number, port->n_irq));
    > > + clk_disable(ssi_ctrl->ssi_clk);
    > > + spin_unlock_bh(&ssi_ctrl->lock);
    > > +
    > > + return 0;
    > > +}
    > > +EXPORT_SYMBOL(ssi_open);
    > > +
    > > +/**
    > > + * ssi_write - write data into the ssi device channel
    > > + * @dev - reference to the ssi device channel to write into.
    > > + * @data - pointer to a 32-bit word data to be written.
    > > + * @count - number of 32-bit word to be written.
    > > + *
    > > + * Return 0 on sucess, a negative value on failure.
    > > + * A success values only indicates that the request has been accepted.

    plural or singular ??

    > > + * Transfer is only completed when the write_done callback is called.
    > > + *
    > > + */
    > > +int ssi_write(struct ssi_device *dev, u32 *data, unsigned int count)
    > > +{
    > > + struct ssi_channel *ch;
    > > + int err;
    > > +
    > > + if (unlikely(!dev || !dev->ch || !data || (count <= 0))) {

    if someone doesn't meet this conditions they deserve to oops I'd say.
    It would avoid badly written drivers.

    > > + dev_err(&dev->device, "Wrong paramenters "
    > > + "ssi_device %p data %p count %d", dev, data, count);
    > > + return -EINVAL;
    > > + }
    > > + if (unlikely(!(dev->ch->flags & SSI_CH_OPEN))) {
    > > + dev_err(&dev->device, "SSI device NOT open\n");
    > > + return -EINVAL;
    > > + }
    > > +
    > > + ch = dev->ch;
    > > + spin_lock_bh(&ch->ssi_port->ssi_controller->lock);
    > > + ch->write_data.addr = data;
    > > + ch->write_data.size = count;

    how about matching the names ??

    > > +
    > > + if (count == 1)
    > > + err = ssi_driver_write_interrupt(ch, data);
    > > + else
    > > + err = ssi_driver_write_dma(ch, data, count);
    > > +
    > > + if (unlikely(err < 0)) {
    > > + ch->write_data.addr = NULL;
    > > + ch->write_data.size = 0;
    > > + }
    > > + spin_unlock_bh(&ch->ssi_port->ssi_controller->lock);
    > > +
    > > + return err;
    > > +
    > > +}
    > > +EXPORT_SYMBOL(ssi_write);
    > > +
    > > +/**
    > > + * ssi_read - read data from the ssi device channel
    > > + * @dev - ssi device channel reference to read data from.
    > > + * @data - pointer to a 32-bit word data to store the data.
    > > + * @count - number of 32-bit word to be stored.
    > > + *
    > > + * Return 0 on sucess, a negative value on failure.
    > > + * A success values only indicates that the request has been accepted.
    > > + * Data is only available in the buffer when the read_done callback is called.
    > > + *
    > > + */
    > > +int ssi_read(struct ssi_device *dev, u32 *data, unsigned int count)
    > > +{
    > > + struct ssi_channel *ch;
    > > + int err;
    > > +
    > > + if (unlikely(!dev || !dev->ch || !data || (count <= 0))) {

    ditto.

    > > + dev_err(&dev->device, "Wrong paramenters "
    > > + "ssi_device %p data %p count %d", dev, data, count);
    > > + return -EINVAL;
    > > + }
    > > + if (unlikely(!(dev->ch->flags & SSI_CH_OPEN))) {
    > > + dev_err(&dev->device, "SSI device NOT open\n");
    > > + return -EINVAL;
    > > + }
    > > +
    > > + ch = dev->ch;
    > > + spin_lock_bh(&ch->ssi_port->ssi_controller->lock);
    > > + ch->read_data.addr = data;
    > > + ch->read_data.size = count;

    how about matching the names ??

    > > +
    > > + if (count == 1)
    > > + err = ssi_driver_read_interrupt(ch, data);
    > > + else
    > > + err = ssi_driver_read_dma(ch, data, count);
    > > +
    > > + if (unlikely(err < 0)) {
    > > + ch->read_data.addr = NULL;
    > > + ch->read_data.size = 0;
    > > + }
    > > + spin_unlock_bh(&ch->ssi_port->ssi_controller->lock);
    > > +
    > > + return err;
    > > +}
    > > +EXPORT_SYMBOL(ssi_read);
    > > +
    > > +void __ssi_write_cancel(struct ssi_channel *ch)
    > > +{
    > > + if (ch->write_data.size == 1)
    > > + ssi_driver_cancel_write_interrupt(ch);
    > > + else if (ch->write_data.size > 1)
    > > + ssi_driver_cancel_write_dma(ch);
    > > +
    > > +}
    > > +/**
    > > + * ssi_write_cancel - Cancel pending write request.
    > > + * @dev - ssi device channel where to cancel the pending write.
    > > + *
    > > + * write_done() callback will not be called after sucess of this function.
    > > + */
    > > +void ssi_write_cancel(struct ssi_device *dev)
    > > +{
    > > + if (unlikely(!dev || !dev->ch)) {
    > > + pr_err(LOG_NAME "Wrong SSI device %p\n", dev);
    > > + return;
    > > + }
    > > + if (unlikely(!(dev->ch->flags & SSI_CH_OPEN))) {
    > > + dev_err(&dev->device, "SSI device NOT open\n");
    > > + return;
    > > + }
    > > +
    > > + spin_lock_bh(&dev->ch->ssi_port->ssi_controller->lock);
    > > + __ssi_write_cancel(dev->ch);
    > > + spin_unlock_bh(&dev->ch->ssi_port->ssi_controller->lock);
    > > +}
    > > +EXPORT_SYMBOL(ssi_write_cancel);
    > > +
    > > +void __ssi_read_cancel(struct ssi_channel *ch)
    > > +{
    > > + if (ch->read_data.size == 1)
    > > + ssi_driver_cancel_read_interrupt(ch);
    > > + else if (ch->read_data.size > 1)
    > > + ssi_driver_cancel_read_dma(ch);
    > > +}
    > > +
    > > +/**
    > > + * ssi_read_cancel - Cancel pending read request.
    > > + * @dev - ssi device channel where to cancel the pending read.
    > > + *
    > > + * read_done() callback will not be called after sucess of this function.
    > > + */
    > > +void ssi_read_cancel(struct ssi_device *dev)
    > > +{
    > > + if (unlikely(!dev || !dev->ch)) {
    > > + pr_err(LOG_NAME "Wrong SSI device %p\n", dev);
    > > + return;
    > > + }
    > > +
    > > + if (unlikely(!(dev->ch->flags & SSI_CH_OPEN))) {
    > > + dev_err(&dev->device, "SSI device NOT open\n");
    > > + return;
    > > + }
    > > +
    > > + spin_lock_bh(&dev->ch->ssi_port->ssi_controller->lock);
    > > + __ssi_read_cancel(dev->ch);
    > > + spin_unlock_bh(&dev->ch->ssi_port->ssi_controller->lock);
    > > +
    > > +}
    > > +EXPORT_SYMBOL(ssi_read_cancel);
    > > +
    > > +/**
    > > + * ssi_ioctl - SSI I/O control
    > > + * @dev - ssi device channel reference to apply the I/O control
    > > + * (or port associated to it)
    ^ trailing whitespace and you can remove a few tabs from the
    second line

    > > + * @command - SSI I/O control command
    > > + * @arg - parameter associated to the control command. NULL, if no parameter.
    > > + *
    > > + * Return 0 on sucess, a negative value on failure.
    > > + *
    > > + */
    > > +int ssi_ioctl(struct ssi_device *dev, unsigned int command, void *arg)
    > > +{
    > > + struct ssi_channel *ch;
    > > + struct ssi_dev *ssi_ctrl;
    > > + void __iomem *base;
    > > + unsigned int port, channel;
    > > + u32 wake;
    > > + int err = 0;
    > > +
    > > + if (unlikely((!dev) ||
    > > + (!dev->ch) ||
    > > + (!dev->ch->ssi_port) ||
    > > + (!dev->ch->ssi_port->ssi_controller)) ||
    > > + (!(dev->ch->flags & SSI_CH_OPEN))) {
    > > + pr_err(LOG_NAME "SSI IOCTL Invalid parameter\n");
    > > + return -EINVAL;
    > > + }
    > > +
    > > +

    remove one blank line.

    > > + ch = dev->ch;
    > > + ssi_ctrl = ch->ssi_port->ssi_controller;
    > > + port = ch->ssi_port->port_number;
    > > + channel = ch->channel_number;
    > > + base = ssi_ctrl->base;
    > > + clk_enable(ssi_ctrl->ssi_clk);
    > > +
    > > + switch (command) {
    > > + case SSI_IOCTL_WAKE_UP:
    > > + /* We only claim once the wake line per channel */
    > > + wake = ssi_inl(base, SSI_SYS_WAKE_REG(port));
    > > + if (!(wake & SSI_WAKE(channel))) {
    > > + clk_enable(ssi_ctrl->ssi_clk);
    > > + ssi_outl(SSI_WAKE(channel), base,
    > > + SSI_SYS_SET_WAKE_REG(port));
    > > + }
    > > + break;
    > > + case SSI_IOCTL_WAKE_DOWN:
    > > + wake = ssi_inl(base, SSI_SYS_WAKE_REG(port));
    > > + if ((wake & SSI_WAKE(channel))) {
    > > + ssi_outl(SSI_WAKE(channel), base,
    > > + SSI_SYS_CLEAR_WAKE_REG(port));
    > > + clk_disable(ssi_ctrl->ssi_clk);
    > > + }
    > > + break;
    > > + case SSI_IOCTL_SEND_BREAK:
    > > + ssi_outl(1, base, SSI_SST_BREAK_REG(port));
    > > + break;
    > > + case SSI_IOCTL_WAKE:
    > > + if (arg == NULL)
    > > + err = -EINVAL;
    > > + else
    > > + *(u32 *)arg = ssi_inl(base, SSI_SYS_WAKE_REG(port));
    > > + break;
    > > + default:
    > > + err = -ENOIOCTLCMD;
    > > + break;
    > > + }
    > > +
    > > + clk_disable(ssi_ctrl->ssi_clk);
    > > +
    > > + return err;
    > > +}
    > > +EXPORT_SYMBOL(ssi_ioctl);
    > > +
    > > +/**
    > > + * ssi_close - close given ssi device channel
    > > + * @dev - reference to ssi device channel.
    > > + */
    > > +void ssi_close(struct ssi_device *dev)
    > > +{
    > > + if (!dev || !dev->ch) {
    > > + pr_err(LOG_NAME "Trying to close wrong SSI device %p\n", dev);
    > > + return;
    > > + }
    > > +
    > > + spin_lock_bh(&dev->ch->ssi_port->ssi_controller->lock);
    > > + if (dev->ch->flags & SSI_CH_OPEN) {
    > > + dev->ch->flags &= ~SSI_CH_OPEN;
    > > + __ssi_write_cancel(dev->ch);
    > > + __ssi_read_cancel(dev->ch);
    > > + }
    > > + spin_unlock_bh(&dev->ch->ssi_port->ssi_controller->lock);
    > > +
    > > +}
    > > +EXPORT_SYMBOL(ssi_close);
    > > +
    > > +/**
    > > + * ssi_dev_set_cb - register read_done() and write_done() callbacks.
    > > + * @dev - reference to ssi device channel where callbacks are associated.
    > > + * @r_cb - callback to signal read transfer completed.
    > > + * @w_cb - callback to signal write transfer completed.

    I'd call them read and write. Or maybe have only one 'complete' and it
    handles read and write inside itself, would have to think a bit more
    about this.

    > > + */
    > > +void ssi_dev_set_cb(struct ssi_device *dev, void (*r_cb)(struct ssi_device *dev)
    > > + , void (*w_cb)(struct ssi_device *dev))
    > > +{
    > > + dev->ch->ops.read_done = r_cb;
    > > + dev->ch->ops.write_done = w_cb;
    > > +}
    > > +EXPORT_SYMBOL(ssi_dev_set_cb);
    > > diff --git a/drivers/misc/ssi/ssi_driver_int.c b/drivers/misc/ssi/ssi_driver_int.c
    > > new file mode 100644
    > > index 0000000..6491e48
    > > --- /dev/null
    > > +++ b/drivers/misc/ssi/ssi_driver_int.c
    > > @@ -0,0 +1,232 @@
    > > +/*
    > > + * ssi_driver_int.c
    > > + *
    > > + * Implements SSI interrupt functionality.
    > > + *
    > > + * Copyright (C) 2007-2008 Nokia Corporation. All rights reserved.
    > > + *
    > > + * Contact: Carlos Chinea <carlos.chinea@nokia.com>
    > > + *
    > > + * This program is free software; you can redistribute it and/or
    > > + * modify it under the terms of the GNU General Public License
    > > + * version 2 as published by the Free Software Foundation.
    > > + *
    > > + * This program is distributed in the hope that it will be useful, but
    > > + * WITHOUT ANY WARRANTY; without even the implied warranty of
    > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    > > + * General Public License for more details.
    > > + *
    > > + * You should have received a copy of the GNU General Public License
    > > + * along with this program; if not, write to the Free Software
    > > + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
    > > + * 02110-1301 USA
    > > + */
    > > +#include "ssi_driver.h"
    > > +
    > > +static void reset_ch_read(struct ssi_channel *ch)
    > > +{
    > > + ch->read_data.addr = NULL;
    > > + ch->read_data.size = 0;
    > > + ch->read_data.lch = -1;
    > > +}
    > > +
    > > +static void reset_ch_write(struct ssi_channel *ch)
    > > +{
    > > + ch->write_data.addr = NULL;
    > > + ch->write_data.size = 0;
    > > + ch->write_data.lch = -1;
    > > +}
    > > +
    > > +int ssi_driver_write_interrupt(struct ssi_channel *ch, u32 *data)
    > > +{
    > > + struct ssi_port *p = ch->ssi_port;
    > > + unsigned int port = p->port_number;
    > > + unsigned int channel = ch->channel_number;
    > > +
    > > + clk_enable(p->ssi_controller->ssi_clk);
    > > + ssi_outl_or(SSI_SST_DATAACCEPT(channel), p->ssi_controller->base,
    > > + SSI_SYS_MPU_ENABLE_REG(port, p->n_irq));
    > > +
    > > +

    one blank line is enough.

    > > + return 0;
    > > +}
    > > +
    > > +int ssi_driver_read_interrupt(struct ssi_channel *ch, u32 *data)
    > > +{
    > > + struct ssi_port *p = ch->ssi_port;
    > > + unsigned int port = p->port_number;
    > > + unsigned int channel = ch->channel_number;
    > > +
    > > + clk_enable(p->ssi_controller->ssi_clk);
    > > +
    > > + ssi_outl_or(SSI_SSR_DATAAVAILABLE(channel), p->ssi_controller->base,
    > > + SSI_SYS_MPU_ENABLE_REG(port, p->n_irq));
    > > +
    > > + clk_disable(p->ssi_controller->ssi_clk);
    > > +
    > > + return 0;
    > > +}
    > > +
    > > +void ssi_driver_cancel_write_interrupt(struct ssi_channel *ch)
    > > +{
    > > + struct ssi_port *p = ch->ssi_port;
    > > + unsigned int port = p->port_number;
    > > + unsigned int channel = ch->channel_number;
    > > + void __iomem *base = p->ssi_controller->base;
    > > + u32 enable;
    > > +
    > > + clk_enable(p->ssi_controller->ssi_clk);
    > > +
    > > + enable = ssi_inl(base, SSI_SYS_MPU_ENABLE_REG(port, p->n_irq));
    > > + if (!(enable & SSI_SST_DATAACCEPT(channel))) {
    > > + dev_dbg(&ch->dev->device, LOG_NAME "Write cancel on not "
    > > + "enabled channel %d ENABLE REG 0x%08X", channel, enable);
    > > + clk_disable(p->ssi_controller->ssi_clk);
    > > + return;
    > > + }
    > > + ssi_outl_and(~SSI_SST_DATAACCEPT(channel), base,
    > > + SSI_SYS_MPU_ENABLE_REG(port, p->n_irq));
    > > + ssi_outl_and(~NOTFULL(channel), base, SSI_SST_BUFSTATE_REG(port));
    > > + reset_ch_write(ch);
    > > +
    > > + clk_disable(p->ssi_controller->ssi_clk);
    > > + clk_disable(p->ssi_controller->ssi_clk);
    > > +

    remove this extra line

    > > +}
    > > +
    > > +void ssi_driver_cancel_read_interrupt(struct ssi_channel *ch)
    > > +{
    > > + struct ssi_port *p = ch->ssi_port;
    > > + unsigned int port = p->port_number;
    > > + unsigned int channel = ch->channel_number;
    > > + void __iomem *base = p->ssi_controller->base;
    > > +
    > > + clk_enable(p->ssi_controller->ssi_clk);
    > > +
    > > + ssi_outl_and(~SSI_SSR_DATAAVAILABLE(channel), base,
    > > + SSI_SYS_MPU_ENABLE_REG(port, p->n_irq));
    > > + ssi_outl_and(~NOTEMPTY(channel), base, SSI_SSR_BUFSTATE_REG(port));
    > > + reset_ch_read(ch);
    > > +
    > > + clk_disable(p->ssi_controller->ssi_clk);
    > > +}
    > > +
    > > +static void do_channel_tx(struct ssi_channel *ch)
    > > +{
    > > + struct ssi_dev *ssi_ctrl = ch->ssi_port->ssi_controller;
    > > + void __iomem *base = ssi_ctrl->base;
    > > + unsigned int n_ch;
    > > + unsigned int n_p;
    > > + unsigned int irq;
    > > +
    > > + n_ch = ch->channel_number;
    > > + n_p = ch->ssi_port->port_number;
    > > + irq = ch->ssi_port->n_irq;
    > > +
    > > + spin_lock(&ssi_ctrl->lock);
    > > +
    > > + if (ch->write_data.addr == NULL) {
    > > + ssi_outl_and(~SSI_SST_DATAACCEPT(n_ch), base,
    > > + SSI_SYS_MPU_ENABLE_REG(n_p, irq));
    > > + reset_ch_write(ch);
    > > + spin_unlock(&ssi_ctrl->lock);
    > > + clk_disable(ssi_ctrl->ssi_clk);
    > > + (*ch->ops.write_done)(ch->dev);
    > > + } else {
    > > + ssi_outl(*(ch->write_data.addr), base,
    > > + SSI_SST_BUFFER_CH_REG(n_p, n_ch));
    > > + ch->write_data.addr = NULL;
    > > + spin_unlock(&ssi_ctrl->lock);
    > > + }
    > > +}
    > > +
    > > +static void do_channel_rx(struct ssi_channel *ch)
    > > +{
    > > + struct ssi_dev *ssi_ctrl = ch->ssi_port->ssi_controller;
    > > + void __iomem *base = ch->ssi_port->ssi_controller->base;
    > > + unsigned int n_ch;
    > > + unsigned int n_p;
    > > + unsigned int irq;
    > > +
    > > + n_ch = ch->channel_number;
    > > + n_p = ch->ssi_port->port_number;
    > > + irq = ch->ssi_port->n_irq;
    > > +
    > > + spin_lock(&ssi_ctrl->lock);
    > > +
    > > + *(ch->read_data.addr) = ssi_inl(base, SSI_SSR_BUFFER_CH_REG(n_p, n_ch));
    > > +
    > > + ssi_outl_and(~SSI_SSR_DATAAVAILABLE(n_ch), base,
    > > + SSI_SYS_MPU_ENABLE_REG(n_p, irq));
    > > + reset_ch_read(ch);
    > > +
    > > + spin_unlock(&ssi_ctrl->lock);
    > > +
    > > + (*ch->ops.read_done)(ch->dev);
    > > +}
    > > +
    > > +void do_ssi_tasklet(unsigned long ssi_port)
    > > +{
    > > + struct ssi_port *pport = (struct ssi_port *)ssi_port;
    > > + struct ssi_dev *ssi_ctrl = pport->ssi_controller;
    > > + void __iomem *base = ssi_ctrl->base;
    > > + unsigned int port = pport->port_number;
    > > + unsigned int channel = 0;
    > > + unsigned int irq = pport->n_irq;
    > > + u32 status_reg;
    > > + u32 enable_reg;
    > > + u32 ssr_err_reg;
    > > + u32 channels_served;
    > > +
    > > + clk_enable(ssi_ctrl->ssi_clk);
    > > +
    > > + channels_served = 0;
    > > + status_reg = ssi_inl(base, SSI_SYS_MPU_STATUS_REG(port, irq));
    > > + enable_reg = ssi_inl(base, SSI_SYS_MPU_ENABLE_REG(port, irq));
    > > +
    > > + for (channel = 0; channel < pport->max_ch; channel++) {
    > > + if ((status_reg & SSI_SST_DATAACCEPT(channel)) &&
    > > + (enable_reg & SSI_SST_DATAACCEPT(channel))) {
    > > + do_channel_tx(&pport->ssi_channel[channel]);
    > > + channels_served |= SSI_SST_DATAACCEPT(channel);
    > > + }
    > > +
    > > + if ((status_reg & SSI_SSR_DATAAVAILABLE(channel)) &&
    > > + (enable_reg & SSI_SSR_DATAAVAILABLE(channel))) {
    > > + do_channel_rx(&pport->ssi_channel[channel]);
    > > + channels_served |= SSI_SSR_DATAAVAILABLE(channel);
    > > + }
    > > + }
    > > +
    > > + if ((status_reg & SSI_BREAKDETECTED) &&
    > > + (enable_reg & SSI_BREAKDETECTED)) {
    > > + dev_info(&ssi_ctrl->pdev->dev,
    > > + "Hardware BREAK on port %d\n", port);
    > > + ssi_outl(0, base, SSI_SSR_BREAK_REG(port));
    > > + ssi_port_event_handler(pport, SSI_EVENT_BREAK_DETECTED, NULL);
    > > + }
    > > +
    > > + if (status_reg & SSI_ERROROCCURED) {
    > > + ssr_err_reg = ssi_inl(base, SSI_SSR_ERROR_REG(port));
    > > + dev_err(&ssi_ctrl->pdev->dev, "SSI ERROR Port %d: 0x%02x\n",
    > > + port, ssr_err_reg);
    > > + ssi_outl(ssr_err_reg, base, SSI_SSR_ERRORACK_REG(port));
    > > + ssi_port_event_handler(pport, SSI_EVENT_ERROR, NULL);
    > > + }
    > > +
    > > + ssi_outl((channels_served | SSI_ERROROCCURED | SSI_BREAKDETECTED), base,
    > > + SSI_SYS_MPU_STATUS_REG(port, irq));
    > > +
    > > + clk_disable(ssi_ctrl->ssi_clk);
    > > + enable_irq(pport->irq);
    > > +}

    I might have more comments on this later. But I'll wait until you come
    with the new version and these comments fixed to look at it again.

    --
    balbi


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