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Subject[PATCH v4 01/12] misc: add driver for sequencer serial port
Date
TI's sequencer serial port (TI-SSP) is a jack-of-all-trades type of serial port
device. It has a built-in programmable execution engine that can be programmed
to operate as almost any serial bus (I2C, SPI, EasyScale, and others).

This patch adds a driver for this controller device. The driver does not
expose a user-land interface. Protocol drivers built on top of this layer are
expected to remain in-kernel.

Signed-off-by: Cyril Chemparathy <cyril@ti.com>
---
arch/arm/mach-davinci/include/mach/ti_ssp.h | 89 +++++
drivers/misc/Kconfig | 10 +
drivers/misc/Makefile | 1 +
drivers/misc/ti_ssp.c | 492 +++++++++++++++++++++++++++
4 files changed, 592 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/mach-davinci/include/mach/ti_ssp.h
create mode 100644 drivers/misc/ti_ssp.c

diff --git a/arch/arm/mach-davinci/include/mach/ti_ssp.h b/arch/arm/mach-davinci/include/mach/ti_ssp.h
new file mode 100644
index 0000000..c98d0f2
--- /dev/null
+++ b/arch/arm/mach-davinci/include/mach/ti_ssp.h
@@ -0,0 +1,89 @@
+/*
+ * Sequencer Serial Port (SSP) driver for Texas Instruments' SoCs
+ *
+ * Copyright (C) 2010 Texas Instruments Inc
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef __TI_SSP_H__
+#define __TI_SSP_H__
+
+struct ti_ssp_dev_data {
+ const char *dev_name;
+ unsigned long iosel; /* see note below */
+ unsigned long config;
+ const void *pdata;
+ size_t pdata_size;
+};
+
+struct ti_ssp_data {
+ unsigned long out_clock;
+ struct ti_ssp_dev_data dev_data[2];
+};
+
+/*
+ * Sequencer port IO pin configuration bits. These do not correlate 1-1 with
+ * the hardware. The iosel field in the port data combines iosel1 and iosel2,
+ * and is therefore not a direct map to register space. It is best to use the
+ * macros below to construct iosel values.
+ *
+ * least significant 16 bits --> iosel1
+ * most significant 16 bits --> iosel2
+ */
+
+#define SSP_IN 0x0000
+#define SSP_DATA 0x0001
+#define SSP_CLOCK 0x0002
+#define SSP_CHIPSEL 0x0003
+#define SSP_OUT 0x0004
+#define SSP_PIN_SEL(pin, v) ((v) << ((pin) * 3))
+#define SSP_PIN_MASK(pin) SSP_PIN_SEL(pin, 0x7)
+#define SSP_INPUT_SEL(pin) ((pin) << 16)
+
+/* Sequencer port config bits */
+#define SSP_EARLY_DIN BIT(8)
+#define SSP_DELAY_DOUT BIT(9)
+
+/* Sequence map definitions */
+#define SSP_CLK_HIGH BIT(0)
+#define SSP_CLK_LOW 0
+#define SSP_DATA_HIGH BIT(1)
+#define SSP_DATA_LOW 0
+#define SSP_CS_HIGH BIT(2)
+#define SSP_CS_LOW 0
+#define SSP_OUT_MODE BIT(3)
+#define SSP_IN_MODE 0
+#define SSP_DATA_REG BIT(4)
+#define SSP_ADDR_REG 0
+
+#define SSP_OPCODE_DIRECT ((0x0) << 5)
+#define SSP_OPCODE_TOGGLE ((0x1) << 5)
+#define SSP_OPCODE_SHIFT ((0x2) << 5)
+#define SSP_OPCODE_BRANCH0 ((0x4) << 5)
+#define SSP_OPCODE_BRANCH1 ((0x5) << 5)
+#define SSP_OPCODE_BRANCH ((0x6) << 5)
+#define SSP_OPCODE_STOP ((0x7) << 5)
+#define SSP_BRANCH(addr) ((addr) << 8)
+#define SSP_COUNT(cycles) ((cycles) << 8)
+
+int ti_ssp_raw_read(struct device *dev);
+int ti_ssp_raw_write(struct device *dev, u32 val);
+int ti_ssp_load(struct device *dev, int offs, u32* prog, int len);
+int ti_ssp_run(struct device *dev, u32 pc, u32 input, u32 *output);
+int ti_ssp_set_mode(struct device *dev, int mode);
+int ti_ssp_set_iosel(struct device *dev, u32 iosel);
+
+#endif /* __TI_SSP_H__ */
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index b743312..a8b7ce3 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -390,6 +390,16 @@ config BMP085
To compile this driver as a module, choose M here: the
module will be called bmp085.

+config TI_SSP
+ tristate "Sequencer Serial Port support"
+ depends on ARCH_DAVINCI_TNETV107X
+ ---help---
+ Say Y here if you want support for the Sequencer Serial Port
+ in a Texas Instruments TNETV107X SoC.
+
+ To compile this driver as a module, choose M here: the
+ module will be called ti_ssp.
+
source "drivers/misc/c2port/Kconfig"
source "drivers/misc/eeprom/Kconfig"
source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 42eab95..7568100 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_SENSORS_TSL2550) += tsl2550.o
obj-$(CONFIG_EP93XX_PWM) += ep93xx_pwm.o
obj-$(CONFIG_DS1682) += ds1682.o
obj-$(CONFIG_TI_DAC7512) += ti_dac7512.o
+obj-$(CONFIG_TI_SSP) += ti_ssp.o
obj-$(CONFIG_C2PORT) += c2port/
obj-$(CONFIG_IWMC3200TOP) += iwmc3200top/
obj-$(CONFIG_HMC6352) += hmc6352.o
diff --git a/drivers/misc/ti_ssp.c b/drivers/misc/ti_ssp.c
new file mode 100644
index 0000000..5d9dc23
--- /dev/null
+++ b/drivers/misc/ti_ssp.c
@@ -0,0 +1,492 @@
+/*
+ * Sequencer Serial Port (SSP) driver for Texas Instruments' SoCs
+ *
+ * Copyright (C) 2010 Texas Instruments Inc
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/wait.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/spinlock.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+
+#include <mach/ti_ssp.h>
+
+/* Register Offsets */
+#define REG_REV 0x00
+#define REG_IOSEL_1 0x04
+#define REG_IOSEL_2 0x08
+#define REG_PREDIV 0x0c
+#define REG_INTR_ST 0x10
+#define REG_INTR_EN 0x14
+#define REG_TEST_CTRL 0x18
+
+/* Per port registers */
+#define PORT_CFG_2 0x00
+#define PORT_ADDR 0x04
+#define PORT_DATA 0x08
+#define PORT_CFG_1 0x0c
+#define PORT_STATE 0x10
+
+#define SSP_PORT_CONFIG_MASK (SSP_EARLY_DIN | SSP_DELAY_DOUT)
+#define SSP_PORT_CLKRATE_MASK 0x0f
+
+#define SSP_SEQRAM_WR_EN BIT(4)
+#define SSP_SEQRAM_RD_EN BIT(5)
+#define SSP_START BIT(15)
+#define SSP_BUSY BIT(10)
+#define SSP_PORT_ASL BIT(7)
+#define SSP_PORT_CFO1 BIT(6)
+
+#define SSP_PORT_SEQRAM_SIZE 32
+
+static const int ssp_port_base[] = {0x040, 0x080};
+static const int ssp_port_seqram[] = {0x100, 0x180};
+
+struct ti_ssp {
+ struct resource *res;
+ struct device *dev;
+ void __iomem *regs;
+ spinlock_t lock;
+ struct clk *clk;
+ int irq;
+ const struct ti_ssp_data *data;
+ wait_queue_head_t wqh;
+};
+
+static inline struct ti_ssp *dev_to_ssp(struct device *dev)
+{
+ return dev_get_drvdata(dev->parent);
+}
+
+static inline int dev_to_port(struct device *dev)
+{
+ return to_platform_device(dev)->id;
+}
+
+/* Register Access Helpers, rmw() functions need to run locked */
+static inline u32 ssp_read(struct ti_ssp *ssp, int reg)
+{
+ return __raw_readl(ssp->regs + reg);
+}
+
+static inline void ssp_write(struct ti_ssp *ssp, int reg, u32 val)
+{
+ __raw_writel(val, ssp->regs + reg);
+}
+
+static inline void ssp_rmw(struct ti_ssp *ssp, int reg, u32 mask, u32 bits)
+{
+ u32 val = ssp_read(ssp, reg);
+ val &= ~mask;
+ val |= bits;
+ ssp_write(ssp, reg, val);
+}
+
+static inline u32 ssp_port_read(struct ti_ssp *ssp, int port, int reg)
+{
+ return ssp_read(ssp, ssp_port_base[port] + reg);
+}
+
+static inline void ssp_port_write(struct ti_ssp *ssp, int port, int reg,
+ u32 val)
+{
+ ssp_write(ssp, ssp_port_base[port] + reg, val);
+}
+
+static inline void ssp_port_rmw(struct ti_ssp *ssp, int port, int reg,
+ u32 mask, u32 bits)
+{
+ ssp_rmw(ssp, ssp_port_base[port] + reg, mask, bits);
+}
+
+static inline void ssp_port_clr_bits(struct ti_ssp *ssp, int port, int reg,
+ u32 bits)
+{
+ ssp_port_rmw(ssp, port, reg, bits, 0);
+}
+
+static inline void ssp_port_set_bits(struct ti_ssp *ssp, int port, int reg,
+ u32 bits)
+{
+ ssp_port_rmw(ssp, port, reg, 0, bits);
+}
+
+/* Called to setup port clock mode, caller must hold ssp->lock */
+static int __set_mode(struct ti_ssp *ssp, int port, int mode)
+{
+ mode &= SSP_PORT_CONFIG_MASK;
+ ssp_port_rmw(ssp, port, PORT_CFG_1, SSP_PORT_CONFIG_MASK, mode);
+
+ return 0;
+}
+
+int ti_ssp_set_mode(struct device *dev, int mode)
+{
+ struct ti_ssp *ssp = dev_to_ssp(dev);
+ int port = dev_to_port(dev);
+ int ret;
+
+ spin_lock(&ssp->lock);
+ ret = __set_mode(ssp, port, mode);
+ spin_unlock(&ssp->lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(ti_ssp_set_mode);
+
+/* Called to setup port iosel, caller must hold ssp->lock */
+static int __set_iosel(struct ti_ssp *ssp, int port, u32 iosel)
+{
+ unsigned val;
+
+ /* IOSEL1 gets the least significant 16 bits */
+ val = ssp_read(ssp, REG_IOSEL_1);
+ val &= 0xffff << (port ? 0 : 16);
+ val |= (iosel & 0xffff) << (port ? 16 : 0);
+ ssp_write(ssp, REG_IOSEL_1, val);
+
+ /* IOSEL2 gets the most significant 16 bits */
+ val = ssp_read(ssp, REG_IOSEL_2);
+ val &= 0x0007 << (port ? 0 : 16);
+ val |= (iosel & 0x00070000) >> (port ? 0 : 16);
+ ssp_write(ssp, REG_IOSEL_2, val);
+
+ return 0;
+}
+
+int ti_ssp_set_iosel(struct device *dev, u32 iosel)
+{
+ struct ti_ssp *ssp = dev_to_ssp(dev);
+ int port = dev_to_port(dev);
+ int ret;
+
+ spin_lock(&ssp->lock);
+ ret = __set_iosel(ssp, port, iosel);
+ spin_unlock(&ssp->lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(ti_ssp_set_iosel);
+
+int ti_ssp_load(struct device *dev, int offs, u32* prog, int len)
+{
+ struct ti_ssp *ssp = dev_to_ssp(dev);
+ int port = dev_to_port(dev);
+ int i;
+
+ if (len > SSP_PORT_SEQRAM_SIZE)
+ return -ENOSPC;
+
+ spin_lock(&ssp->lock);
+
+ /* Enable SeqRAM access */
+ ssp_port_set_bits(ssp, port, PORT_CFG_2, SSP_SEQRAM_WR_EN);
+
+ /* Copy code */
+ for (i = 0; i < len; i++) {
+ __raw_writel(prog[i], ssp->regs + offs + 4*i +
+ ssp_port_seqram[port]);
+ }
+
+ /* Disable SeqRAM access */
+ ssp_port_clr_bits(ssp, port, PORT_CFG_2, SSP_SEQRAM_WR_EN);
+
+ spin_unlock(&ssp->lock);
+
+ return 0;
+}
+EXPORT_SYMBOL(ti_ssp_load);
+
+int ti_ssp_raw_read(struct device *dev)
+{
+ struct ti_ssp *ssp = dev_to_ssp(dev);
+ int port = dev_to_port(dev);
+ u32 val;
+
+ val = ssp_read(ssp, REG_IOSEL_2);
+ val >>= (port ? 27 : 11);
+
+ return val & 0x0f;
+}
+EXPORT_SYMBOL(ti_ssp_raw_read);
+
+int ti_ssp_raw_write(struct device *dev, u32 val)
+{
+ struct ti_ssp *ssp = dev_to_ssp(dev);
+ int port = dev_to_port(dev);
+ u32 mask;
+
+ spin_lock(&ssp->lock);
+
+ val &= 0x0f;
+ val <<= (port ? 22 : 6);
+ mask = 0x0f << (port ? 22 : 6);
+ ssp_rmw(ssp, REG_IOSEL_2, mask, val);
+
+ spin_unlock(&ssp->lock);
+
+ return 0;
+}
+EXPORT_SYMBOL(ti_ssp_raw_write);
+
+static inline int __xfer_done(struct ti_ssp *ssp, int port)
+{
+ return !(ssp_port_read(ssp, port, PORT_CFG_1) & SSP_BUSY);
+}
+
+int ti_ssp_run(struct device *dev, u32 pc, u32 input, u32 *output)
+{
+ struct ti_ssp *ssp = dev_to_ssp(dev);
+ int port = dev_to_port(dev);
+ int ret;
+
+ if (pc & ~(0x3f))
+ return -EINVAL;
+
+ /* Grab ssp->lock to serialize rmw on ssp registers */
+ spin_lock(&ssp->lock);
+
+ ssp_port_write(ssp, port, PORT_ADDR, input >> 16);
+ ssp_port_write(ssp, port, PORT_DATA, input & 0xffff);
+ ssp_port_rmw(ssp, port, PORT_CFG_1, 0x3f, pc);
+
+ /* grab wait queue head lock to avoid race with the isr */
+ spin_lock_irq(&ssp->wqh.lock);
+
+ /* kick off sequence execution in hardware */
+ ssp_port_set_bits(ssp, port, PORT_CFG_1, SSP_START);
+
+ /* drop ssp lock; no register writes beyond this */
+ spin_unlock(&ssp->lock);
+
+ ret = wait_event_interruptible_locked_irq(ssp->wqh,
+ __xfer_done(ssp, port));
+ spin_unlock_irq(&ssp->wqh.lock);
+
+ if (ret < 0)
+ return ret;
+
+ if (output) {
+ *output = (ssp_port_read(ssp, port, PORT_ADDR) << 16) |
+ (ssp_port_read(ssp, port, PORT_DATA) & 0xffff);
+ }
+
+ ret = ssp_port_read(ssp, port, PORT_STATE) & 0x3f; /* stop address */
+
+ return ret;
+}
+EXPORT_SYMBOL(ti_ssp_run);
+
+static irqreturn_t ti_ssp_interrupt(int irq, void *data)
+{
+ struct ti_ssp *ssp = data;
+
+ spin_lock(&ssp->wqh.lock);
+
+ ssp_write(ssp, REG_INTR_ST, 0x3);
+ wake_up_locked(&ssp->wqh);
+
+ spin_unlock(&ssp->wqh.lock);
+
+ return IRQ_HANDLED;
+}
+
+static int __unregister_subdev(struct device *dev, void *unused)
+{
+ platform_device_unregister(to_platform_device(dev));
+ return 0;
+}
+
+static int unregister_subdevs(struct ti_ssp *ssp)
+{
+ return device_for_each_child(ssp->dev, NULL, __unregister_subdev);
+}
+
+static void register_subdevs(struct ti_ssp *ssp)
+{
+ int id;
+
+ for (id = 0; id < 2; id++) {
+ const struct ti_ssp_dev_data *data = &ssp->data->dev_data[id];
+
+ if (!data->dev_name)
+ continue;
+
+ spin_lock(&ssp->lock);
+ __set_iosel(ssp, id, data->iosel);
+ ssp_port_rmw(ssp, id, PORT_CFG_1, SSP_PORT_CONFIG_MASK,
+ data->config);
+ ssp_port_rmw(ssp, id, PORT_CFG_2, SSP_PORT_CLKRATE_MASK, 0);
+ spin_unlock(&ssp->lock);
+
+ platform_device_register_data(ssp->dev, data->dev_name, id,
+ data->pdata, data->pdata_size);
+ }
+}
+
+static int __devinit ti_ssp_probe(struct platform_device *pdev)
+{
+ static struct ti_ssp *ssp;
+ const struct ti_ssp_data *pdata = pdev->dev.platform_data;
+ int ret = 0, prediv = 0xff;
+ unsigned long sysclk;
+ struct device *dev = &pdev->dev;
+
+ ssp = kzalloc(sizeof(*ssp), GFP_KERNEL);
+ if (!ssp) {
+ dev_err(dev, "cannot allocate device info\n");
+ return -ENOMEM;
+ }
+
+ ssp->data = pdata;
+ ssp->dev = dev;
+ dev_set_drvdata(dev, ssp);
+
+ ret = -ENODEV;
+ ssp->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!ssp->res) {
+ dev_err(dev, "cannot determine register area\n");
+ goto error_res;
+ }
+
+ ret = -EINVAL;
+ if (!request_mem_region(ssp->res->start, resource_size(ssp->res),
+ pdev->name)) {
+ dev_err(dev, "cannot claim register memory\n");
+ goto error_res;
+ }
+
+ ret = -ENOMEM;
+ ssp->regs = ioremap(ssp->res->start, resource_size(ssp->res));
+ if (!ssp->regs) {
+ dev_err(dev, "cannot map register memory\n");
+ goto error_map;
+ }
+
+ ret = -EINVAL;
+ ssp->clk = clk_get(dev, NULL);
+ if (IS_ERR(ssp->clk)) {
+ dev_err(dev, "cannot claim device clock\n");
+ goto error_clk;
+ }
+
+ ssp->irq = platform_get_irq(pdev, 0);
+ if (ssp->irq < 0) {
+ dev_err(dev, "unknown irq\n");
+ goto error_irq;
+ }
+
+ ret = request_threaded_irq(ssp->irq, NULL, ti_ssp_interrupt, 0,
+ dev_name(dev), ssp);
+ if (ret < 0) {
+ dev_err(dev, "cannot acquire irq\n");
+ goto error_irq;
+ }
+
+ spin_lock_init(&ssp->lock);
+ init_waitqueue_head(&ssp->wqh);
+
+ /* Power on and initialize SSP */
+ ret = clk_enable(ssp->clk);
+ if (ret)
+ goto error_enable;
+
+ /* Reset registers to a sensible known state */
+ ssp_write(ssp, REG_IOSEL_1, 0);
+ ssp_write(ssp, REG_IOSEL_2, 0);
+ ssp_write(ssp, REG_INTR_EN, 0x3);
+ ssp_write(ssp, REG_INTR_ST, 0x3);
+ ssp_write(ssp, REG_TEST_CTRL, 0);
+ ssp_port_write(ssp, 0, PORT_CFG_1, SSP_PORT_ASL);
+ ssp_port_write(ssp, 1, PORT_CFG_1, SSP_PORT_ASL);
+ ssp_port_write(ssp, 0, PORT_CFG_2, SSP_PORT_CFO1);
+ ssp_port_write(ssp, 1, PORT_CFG_2, SSP_PORT_CFO1);
+
+ sysclk = clk_get_rate(ssp->clk);
+ if (pdata && pdata->out_clock)
+ prediv = (sysclk / pdata->out_clock) - 1;
+ prediv = clamp(prediv, 0, 0xff);
+ ssp_rmw(ssp, REG_PREDIV, 0xff, prediv);
+
+ register_subdevs(ssp);
+
+ return 0;
+
+error_enable:
+ free_irq(ssp->irq, ssp);
+error_irq:
+ clk_put(ssp->clk);
+error_clk:
+ iounmap(ssp->regs);
+error_map:
+ release_mem_region(ssp->res->start, resource_size(ssp->res));
+error_res:
+ kfree(ssp);
+ return ret;
+}
+
+static int __devexit ti_ssp_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ti_ssp *ssp = dev_get_drvdata(dev);
+
+ unregister_subdevs(ssp);
+ clk_disable(ssp->clk);
+ free_irq(ssp->irq, ssp);
+ clk_put(ssp->clk);
+ iounmap(ssp->regs);
+ release_mem_region(ssp->res->start, resource_size(ssp->res));
+ kfree(ssp);
+ dev_set_drvdata(dev, NULL);
+ return 0;
+}
+
+static struct platform_driver ti_ssp_driver = {
+ .probe = ti_ssp_probe,
+ .remove = __devexit_p(ti_ssp_remove),
+ .driver = {
+ .name = "ti-ssp",
+ .owner = THIS_MODULE,
+ }
+};
+
+static int __init ti_ssp_init(void)
+{
+ return platform_driver_register(&ti_ssp_driver);
+}
+arch_initcall_sync(ti_ssp_init);
+
+static void __exit ti_ssp_exit(void)
+{
+ platform_driver_unregister(&ti_ssp_driver);
+}
+module_exit(ti_ssp_exit);
+
+MODULE_DESCRIPTION("Sequencer Serial Port (SSP) Driver");
+MODULE_AUTHOR("Cyril Chemparathy");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:ti_ssp");
--
1.7.0.4


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