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SubjectRe: [MeeGo-Dev][PATCH] Topcliff: Update PCH_I2C driver to 2.6.35
Date
----- Original Message ----- 
From: "Ben Dooks" <ben-i2c@fluff.org>
To: "Masayuki Ohtak" <masa-korg@dsn.okisemi.com>
Cc: "Jean Delvare (PC drivers, core)" <khali@linux-fr.org>; "Ben Dooks (embedded platforms)" <ben-linux@fluff.org>;
"Crane Cai" <crane.cai@amd.com>; "Samuel Ortiz" <sameo@linux.intel.com>; "Linus Walleij" <linus.walleij@stericsson.com>;
"Ralf Baechle" <ralf@linux-mips.org>; "srinidhi kasagar" <srinidhi.kasagar@stericsson.com>; <linux-i2c@vger.kernel.org>;
<linux-kernel@vger.kernel.org>; <joe@perches.com>; <yong.y.wang@intel.com>; <qi.wang@intel.com>;
<andrew.chih.howe.khor@intel.com>; <arjan@linux.intel.com>; "Tomoya MORINAGA" <morinaga526@dsn.okisemi.com>; "Arnd
Bergmann" <arnd@arndb.de>
Sent: Wednesday, September 08, 2010 8:55 AM
Subject: Re: [MeeGo-Dev][PATCH] Topcliff: Update PCH_I2C driver to 2.6.35

> On Fri, Sep 03, 2010 at 07:19:44PM +0900, Masayuki Ohtak wrote:
> > I2C driver of Topcliff PCH
> >
> > Topcliff PCH is the platform controller hub that is going to be used in
> > Intel's upcoming general embedded platform. All IO peripherals in
> > Topcliff PCH are actually devices sitting on AMBA bus.
> > Topcliff PCH has I2C I/F. Using this I/F, it is able to access system
> > devices connected to I2C.
> >
> > Signed-off-by: Masayuki Ohtake <masa-korg@dsn.okisemi.com>
> > Reviewed-by: Linus Walleij <linus.walleij@stericsson.com>
> > ---
> > drivers/i2c/busses/Kconfig | 18 +
> > drivers/i2c/busses/Makefile | 1 +
> > drivers/i2c/busses/i2c-pch.c | 944 ++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 963 insertions(+), 0 deletions(-)
> > create mode 100644 drivers/i2c/busses/i2c-pch.c
> >
> > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> > index bceafbf..c5db1e7 100644
> > --- a/drivers/i2c/busses/Kconfig
> > +++ b/drivers/i2c/busses/Kconfig
> > @@ -613,6 +613,24 @@ config I2C_XILINX
> > This driver can also be built as a module. If so, the module
> > will be called xilinx_i2c.
> >
> > +config PCH_I2C
> > + tristate "PCH I2C of Intel Topcliff"
> > + depends on PCI
> > + help
> > + This driver is for PCH(Platform controller Hub) I2C of Topcliff which
> > + is an IOH(Input/Output Hub) for x86 embedded processor.
> > + This driver can access PCH I2C bus device.
> > +
> > +config PCH_I2C_CH_COUNT
> > + int "PCH I2C the number of channel count"
> > + range 1 2
> > + depends on PCH_I2C
> > + help
> > + This driver is for PCH(Platform controller Hub) I2C of Topcliff which
> > + is an IOH(Input/Output Hub) for x86 embedded processor.
> > + The number of I2C buses/channels supported by the PCH I2C controller.
> > + PCH I2C of Topcliff supports only one channel.
> > +
> > comment "External I2C/SMBus adapter drivers"
> >
> > config I2C_PARPORT
> > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> > index 936880b..aa04135 100644
> > --- a/drivers/i2c/busses/Makefile
> > +++ b/drivers/i2c/busses/Makefile
> > @@ -59,6 +59,7 @@ obj-$(CONFIG_I2C_STU300) += i2c-stu300.o
> > obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
> > obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o
> > obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o
> > +obj-$(CONFIG_PCH_I2C) += i2c-pch.o
> >
> > # External I2C/SMBus adapter drivers
> > obj-$(CONFIG_I2C_PARPORT) += i2c-parport.o
> > diff --git a/drivers/i2c/busses/i2c-pch.c b/drivers/i2c/busses/i2c-pch.c
> > new file mode 100644
> > index 0000000..ae55a83
> > --- /dev/null
> > +++ b/drivers/i2c/busses/i2c-pch.c
> > @@ -0,0 +1,944 @@
> > +/*
> > + * Copyright (C) 2010 OKI SEMICONDUCTOR Co., LTD.
> > + *
> > + * 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; version 2 of the License.
> > + *
> > + * 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/module.h>
> > +#include <linux/kernel.h>
> > +#include <linux/delay.h>
> > +#include <linux/init.h>
> > +#include <linux/errno.h>
> > +#include <linux/i2c.h>
> > +#include <linux/fs.h>
> > +#include <linux/io.h>
> > +#include <linux/types.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/jiffies.h>
> > +#include <linux/pci.h>
> > +#include <linux/mutex.h>
> > +#include <linux/ktime.h>
> > +
> > +#define PCH_MAX_CHN CONFIG_PCH_I2C_CH_COUNT /* Maximum I2C channels
> > + available */
> > +#define PCH_EVENT_SET 0 /* I2C Interrupt Event Set Status */
> > +#define PCH_EVENT_NONE 1 /* I2C Interrupt Event Clear Status */
> > +#define PCH_MAX_CLK 100000 /* Maximum Clock speed in MHz */
> > +#define PCH_BUFFER_MODE_ENABLE 0x0002 /* flag for Buffer mode enable */
> > +#define PCH_EEPROM_SW_RST_MODE_ENABLE 0x0008 /* EEPROM SW RST enable flag */
> > +
> > +#define PCH_I2CSADR 0x00 /* I2C slave address register */
> > +#define PCH_I2CCTL 0x04 /* I2C control register */
> > +#define PCH_I2CSR 0x08 /* I2C status register */
> > +#define PCH_I2CDR 0x0C /* I2C data register */
> > +#define PCH_I2CMON 0x10 /* I2C bus monitor register */
> > +#define PCH_I2CBC 0x14 /* I2C bus transfer rate setup counter */
> > +#define PCH_I2CMOD 0x18 /* I2C mode register */
> > +#define PCH_I2CBUFSLV 0x1C /* I2C buffer mode slave address register */
> > +#define PCH_I2CBUFSUB 0x20 /* I2C buffer mode subaddress register */
> > +#define PCH_I2CBUFFOR 0x24 /* I2C buffer mode format register */
> > +#define PCH_I2CBUFCTL 0x28 /* I2C buffer mode control register */
> > +#define PCH_I2CBUFMSK 0x2C /* I2C buffer mode interrupt mask register */
> > +#define PCH_I2CBUFSTA 0x30 /* I2C buffer mode status register */
> > +#define PCH_I2CBUFLEV 0x34 /* I2C buffer mode level register */
> > +#define PCH_I2CESRFOR 0x38 /* EEPROM software reset mode format register */
> > +#define PCH_I2CESRCTL 0x3C /* EEPROM software reset mode ctrl register */
> > +#define PCH_I2CESRMSK 0x40 /* EEPROM software reset mode */
> > +#define PCH_I2CESRSTA 0x44 /* EEPROM software reset mode status register */
> > +#define PCH_I2CTMR 0x48 /* I2C timer register */
> > +#define PCH_I2CSRST 0xFC /* I2C reset register */
> > +#define PCH_I2CNF 0xF8 /* I2C noise filter register */
> > +
> > +#define BUS_IDLE_TIMEOUT 20
> > +#define PCH_I2CCTL_I2CMEN 0x0080
> > +#define TEN_BIT_ADDR_DEFAULT 0xF000
> > +#define TEN_BIT_ADDR_MASK 0xF0
> > +#define PCH_START 0x0020
> > +#define PCH_ESR_START 0x0001
> > +#define PCH_BUFF_START 0x1
> > +#define PCH_REPSTART 0x0004
> > +#define PCH_ACK 0x0008
> > +#define PCH_GETACK 0x0001
> > +#define CLR_REG 0x0
> > +#define I2C_RD 0x1
> > +#define I2CMCF_BIT 0x0080
> > +#define I2CMIF_BIT 0x0002
> > +#define I2CMAL_BIT 0x0010
> > +#define I2CBMFI_BIT 0x0001
> > +#define I2CBMAL_BIT 0x0002
> > +#define I2CBMNA_BIT 0x0004
> > +#define I2CBMTO_BIT 0x0008
> > +#define I2CBMIS_BIT 0x0010
> > +#define I2CESRFI_BIT 0X0001
> > +#define I2CESRTO_BIT 0x0002
> > +#define I2CESRFIIE_BIT 0x1
> > +#define I2CESRTOIE_BIT 0x2
> > +#define I2CBMDZ_BIT 0x0040
> > +#define I2CBMAG_BIT 0x0020
> > +#define I2CMBB_BIT 0x0020
> > +#define BUFFER_MODE_MASK (I2CBMFI_BIT | I2CBMAL_BIT | I2CBMNA_BIT | \
> > + I2CBMTO_BIT | I2CBMIS_BIT)
> > +#define I2C_ADDR_MSK 0xFF
> > +#define I2C_MSB_2B_MSK 0x300
> > +#define FAST_MODE_CLK 400
> > +#define FAST_MODE_EN 0x0001
> > +#define SUB_ADDR_LEN_MAX 4
> > +#define BUF_LEN_MAX 32
> > +#define PCH_BUFFER_MODE 0x1
> > +#define EEPROM_SW_RST_MODE 0x0002
> > +#define NORMAL_INTR_ENBL 0x0300
> > +#define EEPROM_RST_INTR_ENBL (I2CESRFIIE_BIT | I2CESRTOIE_BIT)
> > +#define EEPROM_RST_INTR_DISBL 0x0
> > +#define BUFFER_MODE_INTR_ENBL 0x001F
> > +#define BUFFER_MODE_INTR_DISBL 0x0
> > +#define NORMAL_MODE 0x0
> > +#define BUFFER_MODE 0x1
> > +#define EEPROM_SR_MODE 0x2
> > +#define I2C_TX_MODE 0x0010
> > +#define PCH_BUF_TX 0xFFF7
> > +#define PCH_BUF_RD 0x0008
> > +#define I2C_ERROR_MASK (I2CESRTO_EVENT | I2CBMIS_EVENT | I2CBMTO_EVENT | \
> > + I2CBMNA_EVENT | I2CBMAL_EVENT | I2CMAL_EVENT)
> > +#define I2CMAL_EVENT 0x0001
> > +#define I2CMCF_EVENT 0x0002
> > +#define I2CBMFI_EVENT 0x0004
> > +#define I2CBMAL_EVENT 0x0008
> > +#define I2CBMNA_EVENT 0x0010
> > +#define I2CBMTO_EVENT 0x0020
> > +#define I2CBMIS_EVENT 0x0040
> > +#define I2CESRFI_EVENT 0x0080
> > +#define I2CESRTO_EVENT 0x0100
> > +#define PCI_DEVICE_ID_PCH_I2C 0x8817
> > +
> > +#define pch_dbg(adap, fmt, arg...) \
> > + dev_dbg(adap->pch_adapter.dev.parent, "%s :" fmt, __func__, ##arg)
> > +
> > +#define pch_err(adap, fmt, arg...) \
> > + dev_err(adap->pch_adapter.dev.parent, "%s :" fmt, __func__, ##arg)
> > +
> > +#define pch_pci_err(pdev, fmt, arg...) \
> > + dev_err(&pdev->dev, "%s :" fmt, __func__, ##arg)
> > +
> > +#define pch_pci_dbg(pdev, fmt, arg...) \
> > + dev_dbg(&pdev->dev, "%s :" fmt, __func__, ##arg)
> > +
> > +/**
> > + * struct i2c_algo_pch_data - for I2C driver functionalities
> > + * @p_adapter_info: stores the reference to adapter_info structure
> > + * @pch_adapter: stores the reference to i2c_adapter structure
> > + * @pch_base_address: specifies the remapped base address
> > + * @pch_buff_mode_en: specifies if buffer mode is enabled
> > + * @pch_event_flag: specifies occurrence of interrupt events
> > + * @pch_xfer_in_progress: specifies whether the transfer is completed
> > + */
> > +struct i2c_algo_pch_data {
> > + struct adapter_info *p_adapter_info;
> > + struct i2c_adapter pch_adapter;
> > + void __iomem *pch_base_address;
> > + int pch_buff_mode_en;
> > + u32 pch_event_flag;
> > + bool pch_xfer_in_progress;
> > +};
> > +
> > +/**
> > + * struct adapter_info - This structure holds the adapter information for the
> > + PCH i2c controller
> > + * @pch_data: stores a list of i2c_algo_pch_data
> > + * @pch_suspended: specifies whether the system is suspended or not
> > + * perhaps with more lines and words.
> > + *
> > + * pch_data has as many elements as maximum I2C channels
> > + */
> > +struct adapter_info {
> > + struct i2c_algo_pch_data pch_data[PCH_MAX_CHN];
> > + bool pch_suspended;
> > +};
> > +
> > +
> > +static int pch_i2c_speed = 100; /* I2C bus speed in Kbps */
> > +static int pch_clk = 50000; /* specifies I2C clock speed in KHz */
> > +static wait_queue_head_t pch_event;
> > +static DEFINE_MUTEX(pch_mutex);
> > +
> > +static struct pci_device_id __devinitdata pch_pcidev_id[] = {
> > + {PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_PCH_I2C)},
> > + {0,}
> > +};
> > +
> > +static irqreturn_t pch_handler_ch0(int irq, void *pData);
> > +static irqreturn_t(*pch_handler_list[PCH_MAX_CHN]) (int irq, void *pData) = {
> > + pch_handler_ch0,
> > +};
> > +
> > +static inline void pch_setbit(void __iomem *addr, u32 offset, u32 bitmask)
> > +{
> > + u32 val;
> > + val = ioread32(addr + offset);
> > + val |= bitmask;
> > + iowrite32(val, addr + offset);
> > +}
> > +
> > +static inline void pch_clrbit(void __iomem *addr, u32 offset, u32 bitmask)
> > +{
> > + u32 val;
> > + val = ioread32(addr + offset);
> > + val &= (~bitmask);
> > + iowrite32(val, addr + offset);
> > +}
> > +
> > +/**
> > + * pch_init() - hardware initialization of I2C module
> > + * @adap: Pointer to struct i2c_algo_pch_data.
> > + */
> > +static void pch_init(struct i2c_algo_pch_data *adap)
> > +{
> > + u32 pch_i2cbc;
> > + u32 pch_i2ctmr;
> > + u32 reg_value;
> > + void __iomem *p = adap->pch_base_address;
>
> my personal preference is to put the larger items at the top of the list.
>
> > + /* reset I2C controller */
> > + iowrite32(0x01, p + PCH_I2CSRST);
> > + iowrite32(0x0, p + PCH_I2CSRST);
> > + /* Initialize I2C registers */
> > + iowrite32(CLR_REG, p + PCH_I2CCTL);
> > + iowrite32(CLR_REG, p + PCH_I2CMOD);
> > + iowrite32(CLR_REG, p + PCH_I2CBUFFOR);
> > + iowrite32(CLR_REG, p + PCH_I2CBUFSLV);
> > + iowrite32(CLR_REG, p + PCH_I2CBUFSUB);
> > + iowrite32(CLR_REG, p + PCH_I2CBUFMSK);
> > + iowrite32(CLR_REG, p + PCH_I2CESRFOR);
> > + iowrite32(CLR_REG, p + PCH_I2CESRMSK);
> > + iowrite32(0x21, p + PCH_I2CNF);
> > +
> > + reg_value = PCH_I2CCTL_I2CMEN;
> > + pch_setbit((adap->pch_base_address), PCH_I2CCTL,
> > + PCH_I2CCTL_I2CMEN);
> > +
> > + if (pch_i2c_speed != 400)
> > + pch_i2c_speed = 100;
> > +
> > + if (pch_i2c_speed == FAST_MODE_CLK) {
> > + reg_value |= FAST_MODE_EN;
> > + pch_dbg(adap, "Fast mode enabled\n");
> > + }
> > +
> > + if (pch_clk <= 0 || pch_clk > PCH_MAX_CLK)
> > + pch_clk = 62500;
> > +
> > + pch_i2cbc = ((pch_clk) + (pch_i2c_speed * 4)) / (pch_i2c_speed * 8);
>
> do you really need the () around pch_clk? there seems to be quite a few
> of these around. you also don't need them around pch_i2c_speed * 4. I would
> like to see these gone.
>
> > + /* Set transfer speed in I2CBC */
> > + iowrite32(pch_i2cbc, p + PCH_I2CBC);
> > +
> > + pch_i2ctmr = (pch_clk) / 8;
> > + iowrite32(pch_i2ctmr, p + PCH_I2CTMR);
> > +
> > + reg_value |= NORMAL_INTR_ENBL; /* Enable interrupts in normal mode */
> > + iowrite32(reg_value, p + PCH_I2CCTL);
> > +
> > + pch_dbg(adap,
> > + "I2CCTL=%x pch_i2cbc=%x pch_i2ctmr=%x Enable interrupts\n",
> > + ioread32(p + PCH_I2CCTL), pch_i2cbc, pch_i2ctmr);
> > +
> > + init_waitqueue_head(&pch_event);
> > +}
> > +
> > +static inline int ktime_lt(const ktime_t cmp1, const ktime_t cmp2)
> > +{
> > + return cmp1.tv64 < cmp2.tv64;
> > +}
>
> surely this should be with the ktime headers?


You mean should we use keime_sub_ns instead of our ktime_lt ?



>
> > +/**
> > + * pch_wait_for_bus_idle() - check the status of bus.
> > + * @adap: Pointer to struct i2c_algo_pch_data.
> > + * @timeout: waiting time counter (us).
> > + */
> > +static s32 pch_wait_for_bus_idle(struct i2c_algo_pch_data *adap,
> > + s32 timeout)
> > +{
> > + void __iomem *p = adap->pch_base_address;
> > +
> > + /* MAX timeout value is timeout*1000*1000nsec */
> > + ktime_t ns_val = ktime_add_ns(ktime_get(), timeout*1000*1000);
> > + do {
> > + if ((ioread32(p + PCH_I2CSR) & I2CMBB_BIT) == 0)
> > + break;
> > + msleep(1);
> > + } while (ktime_lt(ktime_get(), ns_val));
> > +
> > + pch_dbg(adap, "I2CSR = %x\n", ioread32(p + PCH_I2CSR));
> > +
> > + if (timeout == 0) {
> > + pch_err(adap, "return%d\n", -ETIME);
>
> how about just printing timedout? would be easier to work out what
> happened.
>
> > + return -ETIME;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * pch_start() - Generate I2C start condition in normal mode.
> > + * @adap: Pointer to struct i2c_algo_pch_data.
> > + *
> > + * Generate I2C start condition in normal mode by setting I2CCTL.I2CMSTA to 1.
> > + */
> > +static void pch_start(struct i2c_algo_pch_data *adap)
> > +{
> > + void __iomem *p = adap->pch_base_address;
> > + pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
> > + pch_setbit((adap->pch_base_address), PCH_I2CCTL, PCH_START);
>
> again with the ()s.
>
> > +static s32 pch_getack(struct i2c_algo_pch_data *adap)
> > +{
> > + u32 reg_val;
> > + void __iomem *p = adap->pch_base_address;
> > + reg_val = ioread32(p + PCH_I2CSR) & PCH_GETACK;
> > +
> > + if (reg_val != 0) {
> > + pch_err(adap, "return%d\n", -EPROTO);
> > + return -EPROTO;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * pch_stop() - generate stop condition in normal mode.
> > + * @adap: Pointer to struct i2c_algo_pch_data.
> > + */
> > +static void pch_stop(struct i2c_algo_pch_data *adap)
> > +{
> > + void __iomem *p = adap->pch_base_address;
> > + pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
> > + /* clear the start bit */
> > + pch_clrbit((adap->pch_base_address), PCH_I2CCTL, PCH_START);
> > +}
> > +
> > +/**
> > + * pch_repstart() - generate repeated start condition in normal mode
> > + * @adap: Pointer to struct i2c_algo_pch_data.
> > + */
> > +static void pch_repstart(struct i2c_algo_pch_data *adap)
> > +{
> > + void __iomem *p = adap->pch_base_address;
> > + pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
> > + pch_setbit((adap->pch_base_address), PCH_I2CCTL, PCH_REPSTART);
> > +}
> > +
> > +/**
> > + * pch_writebytes() - write data to I2C bus in normal mode
> > + * @i2c_adap: Pointer to the struct i2c_adapter.
> > + * @last: specifies whether last message or not.
> > + * In the case of compound mode it will be 1 for last message,
> > + * otherwise 0.
> > + * @first: specifies whether first message or not.
> > + * 1 for first message otherwise 0.
> > + */
> > +static s32 pch_writebytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs,
> > + u32 last, u32 first)
> > +{
> > + struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
> > + u8 *buf;
> > + u32 length;
> > + u32 addr;
> > + u32 addr_2_msb;
> > + u32 addr_8_lsb;
> > + s32 wrcount;
> > + void __iomem *p = adap->pch_base_address;
> > + length = msgs->len;
> > + buf = msgs->buf;
> > + addr = msgs->addr;
>
> blank line between decls and code please.
>
> > + /* enable master tx */
> > + pch_setbit((adap->pch_base_address), PCH_I2CCTL, I2C_TX_MODE);
>
> this is the last warning on ()s...
>
> > + pch_dbg(adap, "I2CCTL = %x msgs->len = %d\n", ioread32(p + PCH_I2CCTL),
> > + length);
> > +
> > + if (first) {
> > + if (pch_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
> > + return -ETIME;
> > + }
>
> hmm, -ETIME versus -ETIMEDOUT elsewhere?
>
> > + if (msgs->flags & I2C_M_TEN) {
> > + addr_2_msb = ((addr & I2C_MSB_2B_MSK) >> 7);
> > + iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
> > + if (first)
> > + pch_start(adap);
> > + if ((pch_wait_for_xfer_complete(adap) == 0) &&
> > + (pch_getack(adap) == 0)) {
>
> and no need for most of the ()s here...
>
> > + addr_8_lsb = (addr & I2C_ADDR_MSK);
> > + iowrite32(addr_8_lsb, p + PCH_I2CDR);
> > + } else {
> > + pch_stop(adap);
> > + return -ETIME;
> > + }
> > + } else {
> > + /* set 7 bit slave address and R/W bit as 0 */
> > + iowrite32(addr << 1, p + PCH_I2CDR);
> > + if (first)
> > + pch_start(adap);
> > + }
> > +
> > + if ((pch_wait_for_xfer_complete(adap) == 0) &&
> > + (pch_getack(adap) == 0)) {
> > + for (wrcount = 0; wrcount < length; ++wrcount) {
> > + /* write buffer value to I2C data register */
> > + iowrite32(buf[wrcount], p + PCH_I2CDR);
> > + pch_dbg(adap, "writing %x to Data register\n",
> > + buf[wrcount]);
> > +
> > + if (pch_wait_for_xfer_complete(adap) != 0)
> > + return -ETIME;
> > +
> > + if (pch_getack(adap))
> > + return -ETIME;
>
> you sure it isn't -EIO here if ack problem?
>
> > + }
> > +
> > + /* check if this is the last message */
> > + if (last)
> > + pch_stop(adap);
> > + else
> > + pch_repstart(adap);
> > + } else {
> > + pch_stop(adap);
> > + return -EIO;
> > + }
> > +
> > + pch_dbg(adap, "return=%d\n", wrcount);
> > +
> > + return wrcount;
> > +}
> > +
> > +/**
> > + * pch_sendack() - send ACK
> > + * @adap: Pointer to struct i2c_algo_pch_data.
> > + */
> > +static void pch_sendack(struct i2c_algo_pch_data *adap)
> > +{
> > + void __iomem *p = adap->pch_base_address;
> > + pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
> > + pch_clrbit((adap->pch_base_address), PCH_I2CCTL, PCH_ACK);
> > +}
> > +
> > +/**
> > + * pch_sendnack() - send NACK
> > + * @adap: Pointer to struct i2c_algo_pch_data.
> > + */
> > +static void pch_sendnack(struct i2c_algo_pch_data *adap)
> > +{
> > + void __iomem *p = adap->pch_base_address;
> > + pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
> > + pch_setbit((adap->pch_base_address), PCH_I2CCTL, PCH_ACK);
> > +}
> > +
> > +/**
> > + * pch_readbytes() - read data from I2C bus in normal mode.
> > + * @i2c_adap: Pointer to the struct i2c_adapter.
> > + * @msgs: Pointer to i2c_msg structure.
> > + * @last: specifies whether last message or not.
> > + * @first: specifies whether first message or not.
> > + */
> > +s32 pch_readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs,
> > + u32 last, u32 first)
> > +{
> > + struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
> > +
> > + u8 *buf;
> > + u32 count;
> > + u32 length;
> > + u32 addr;
> > + u32 addr_2_msb;
> > + void __iomem *p = adap->pch_base_address;
> > + length = msgs->len;
> > + buf = msgs->buf;
> > + addr = msgs->addr;
> > +
> > + /* enable master reception */
> > + pch_clrbit((adap->pch_base_address), PCH_I2CCTL, I2C_TX_MODE);
> > +
> > + if (first) {
> > + if (pch_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
> > + return -ETIME;
> > + }
> > +
> > + if (msgs->flags & I2C_M_TEN) {
> > + addr_2_msb = (((addr & I2C_MSB_2B_MSK) >> 7) | (I2C_RD));
> > + iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
> > +
> > + } else {
> > + /* 7 address bits + R/W bit */
> > + addr = (((addr) << 1) | (I2C_RD));
> > + iowrite32(addr, p + PCH_I2CDR);
> > + }
> > +
> > + /* check if it is the first message */
> > + if (first)
> > + pch_start(adap);
> > +
> > + if ((pch_wait_for_xfer_complete(adap) == 0) &&
> > + (pch_getack(adap) == 0)) {
> > + pch_dbg(adap, "return %d\n", 0);
> > +
> > + if (length == 0) {
> > + pch_stop(adap);
> > + ioread32(p + PCH_I2CDR); /* Dummy read needs */
> > +
> > + count = length;
> > + } else {
> > + int read_index;
> > + int loop;
> > + pch_sendack(adap);
> > +
> > + /* Dummy read */
> > + for (loop = 1, read_index = 0; loop < length; loop++) {
> > + buf[read_index] = ioread32(p + PCH_I2CDR);
> > +
> > + if (loop != 1)
> > + read_index++;
> > +
> > + if (pch_wait_for_xfer_complete(adap) != 0) {
> > + pch_stop(adap);
> > + return -ETIME;
> > + }
> > + } /* end for */
> > +
> > + pch_sendnack(adap);
> > +
> > + buf[read_index] = ioread32(p + PCH_I2CDR);
> > +
> > + if (length != 1)
> > + read_index++;
> > +
> > + if (pch_wait_for_xfer_complete(adap) == 0) {
> > + if (last)
> > + pch_stop(adap);
> > + else
> > + pch_repstart(adap);
> > +
> > + buf[read_index++] = ioread32(p + PCH_I2CDR);
> > + count = read_index;
> > + } else {
> > + count = -ETIME;
> > + }
> > +
> > + }
> > + } else {
> > + count = -ETIME;
> > + pch_stop(adap);
> > + }
> > +
> > + return count;
> > +}
> > +
> > +/**
> > + * pch_cb_ch0() - Interrupt handler Call back function
> > + * @adap: Pointer to struct i2c_algo_pch_data.
> > + */
> > +static void pch_cb_ch0(struct i2c_algo_pch_data *adap)
> > +{
> > + u32 sts;
> > + void __iomem *p = adap->pch_base_address;
> > +
> > + sts = ioread32(p + PCH_I2CSR);
> > + sts &= (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT);
> > + if (I2CMAL_BIT & sts)
> > + adap->pch_event_flag |= I2CMAL_EVENT;
> > +
> > + if (I2CMCF_BIT & sts)
> > + adap->pch_event_flag |= I2CMCF_EVENT;
> > +
> > + /* clear the applicable bits */
> > + pch_clrbit((adap->pch_base_address), PCH_I2CSR, sts);
> > +
> > + pch_dbg(adap, "PCH_I2CSR = %x\n", ioread32(p + PCH_I2CSR));
> > +
> > + wake_up_interruptible(&pch_event);
> > +}
> > +
> > +/**
> > + * pch_handler_ch0() - interrupt handler for the PCH I2C controller
> > + * @irq: irq number.
> > + * @pData: cookie passed back to the handler function.
> > + */
> > +static irqreturn_t pch_handler_ch0(int irq, void *pData)
> > +{
> > + s32 reg_val;
> > +
> > + struct i2c_algo_pch_data *adap_data = (struct i2c_algo_pch_data *)pData;
> > + void __iomem *p = adap_data->pch_base_address;
> > + u32 mode = ioread32(p + PCH_I2CMOD) & (BUFFER_MODE | EEPROM_SR_MODE);
> > +
> > + if (mode != NORMAL_MODE) {
> > + pch_err(adap_data, "I2C mode is not supported\n");
> > + return IRQ_NONE;
> > + }
> > +
> > + reg_val = ioread32(p + PCH_I2CSR);
> > + if (reg_val & (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT))
> > + pch_cb_ch0(adap_data);
> > + else
> > + return IRQ_NONE;
> > +
> > + return IRQ_HANDLED;
> > +}
> > +#if 0
> > + if (mode == NORMAL_MODE) {
> > + reg_val = ioread32(p + PCH_I2CSR);
> > + if (reg_val & (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT))
> > + pch_cb_ch0(adap_data);
> > + else
> > + goto err_out;
> > + } else {
> > + pch_err(adap_data, "I2C mode is not supported\n");
> > + goto err_out;
> > + }
> > + return IRQ_HANDLED;
> > +
> > +err_out:
> > + return IRQ_NONE;
> > +}
> > +#endif
>
> please, no #if 0. either remove completely or do something with it.
>
> > +/**
> > + * pch_xfer() - Reading adnd writing data through I2C bus
> > + * @i2c_adap: Pointer to the struct i2c_adapter.
> > + * @msgs: Pointer to i2c_msg structure.
> > + * @num: number of messages.
> > + */
> > +static s32 pch_xfer(struct i2c_adapter *i2c_adap,
> > + struct i2c_msg *msgs, s32 num)
> > +{
> > + struct i2c_msg *pmsg;
> > + u32 i;
> > + u32 status;
> > + u32 msglen;
> > + u32 subaddrlen;
> > + s32 ret;
> > +
> > + struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
> > +
> > + ret = mutex_lock_interruptible(&pch_mutex);
> > + if (ret)
> > + return -ERESTARTSYS;
> > +
> > + if (adap->p_adapter_info->pch_suspended) {
> > + mutex_unlock(&pch_mutex);
> > + return -EBUSY;
> > + }
> > +
> > + pch_dbg(adap, "adap->p_adapter_info->pch_suspended is %d\n",
> > + adap->p_adapter_info->pch_suspended);
> > + /* transfer not completed */
> > + adap->pch_xfer_in_progress = true;
> > +
> > + for (i = 0; i < num; i++) {
> > + pmsg = &msgs[i];
> > + pmsg->flags |= adap->pch_buff_mode_en;
> > + status = pmsg->flags;
> > + pch_dbg(adap,
> > + "After invoking I2C_MODE_SEL :flag= 0x%x\n", status);
> > + /* calculate sub address length and message length */
> > + /* these are applicable only for buffer mode */
> > + subaddrlen = pmsg->buf[0];
> > + /* calculate actual message length excluding
> > + * the sub address fields */
> > + msglen = (pmsg->len) - (subaddrlen + 1);
> > + if (status & (I2C_M_RD)) {
> > + pch_dbg(adap, "invoking pch_readbytes\n");
> > + ret = pch_readbytes(i2c_adap, pmsg, (i + 1 == num),
> > + (i == 0));
> > + } else {
> > + pch_dbg(adap, "invoking pch_writebytes\n");
> > + ret = pch_writebytes(i2c_adap, pmsg, (i + 1 == num),
> > + (i == 0));
> > + }
> > +
> > + }
> > +
> > + adap->pch_xfer_in_progress = false; /* transfer completed */
> > +
> > + mutex_unlock(&pch_mutex);
> > +
> > + return ret;
> > +}
> > +
> > +/**
> > + * pch_func() - return the functionality of the I2C driver
> > + * @adap: Pointer to struct i2c_algo_pch_data.
> > + */
> > +static u32 pch_func(struct i2c_adapter *adap)
> > +{
> > + u32 ret;
> > + ret = I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
> > + return ret;
> > +}
>
> how about just return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
>
> > +static struct i2c_algorithm pch_algorithm = {
> > + .master_xfer = pch_xfer,
> > + .functionality = pch_func
> > +};
> > +
> > +/**
> > + * pch_disbl_int() - Disable PCH I2C interrupts
> > + * @adap: Pointer to struct i2c_algo_pch_data.
> > + */
> > +static void pch_disbl_int(struct i2c_algo_pch_data *adap)
> > +{
> > + void __iomem *p = adap->pch_base_address;
> > +
> > + pch_clrbit((adap->pch_base_address), PCH_I2CCTL,
> > + NORMAL_INTR_ENBL);
> > +
> > + iowrite32(EEPROM_RST_INTR_DISBL, p + PCH_I2CESRMSK);
> > +
> > + iowrite32(BUFFER_MODE_INTR_DISBL, p + PCH_I2CBUFMSK);
> > +}
> > +
> > +static int __devinit pch_probe(struct pci_dev *pdev,
> > + const struct pci_device_id *id)
> > +{
> > + int i;
> > + void __iomem *base_addr;
> > + s32 ret;
> > + struct adapter_info *adap_info =
> > + kzalloc((sizeof(struct adapter_info)), GFP_KERNEL);
>
> this would be a good case to putting the kzalloc() on a different line
> from the decleration.
>
> > + pch_pci_dbg(pdev, "Entered.\n");
> > +
> > + if (adap_info == NULL) {
> > + pch_pci_err(pdev, "Memory allocation FAILED\n");
> > + return -ENOMEM;
> > + }
> > +
> > + ret = pci_enable_device(pdev);
> > + if (ret) {
> > + pch_pci_err(pdev, "pci_enable_device FAILED\n");
> > + goto err_pci_enable;
> > + }
>
> do you really need to put FAILED in capitals here?


You mean should we use "failed" not "FAILED" ?



>
> > + ret = pci_request_regions(pdev, KBUILD_MODNAME);
> > + if (ret) {
> > + pch_pci_err(pdev, "pci_request_regions FAILED\n");
> > + goto err_pci_req;
> > + }
> > +
> > + base_addr = pci_iomap(pdev, 1, 0);
> > +
> > + if (base_addr == 0) {
>
> surley that would be == NULL?
>
> > + pch_pci_err(pdev, "pci_iomap FAILED\n");
> > + ret = -ENOMEM;
> > + goto err_pci_iomap;
> > + }
> > +
> > + adap_info->pch_suspended = false;
> > +
> > + for (i = 0; i < PCH_MAX_CHN; i++) {
> > + adap_info->pch_data[i].p_adapter_info = adap_info;
>
> looks like a pointer to adap_info->pch_data[i] would make the source
> smaller and a bit easier to read.


This code have already modified.(PCH_MAX_CHN is deleted.)
Please refer the latest our i2c patch.

>
> > + adap_info->pch_data[i].pch_adapter.owner = THIS_MODULE;
> > + adap_info->pch_data[i].pch_adapter.class = I2C_CLASS_HWMON;
> > + strcpy(adap_info->pch_data[i].pch_adapter.name, KBUILD_MODNAME);
> > + adap_info->pch_data[i].pch_adapter.algo = &pch_algorithm;
> > + adap_info->pch_data[i].pch_adapter.algo_data =
> > + &adap_info->pch_data[i];
> > +
> > + /* (i * 0x80) + base_addr; */
> > + adap_info->pch_data[i].pch_base_address = base_addr;
> > +
> > + adap_info->pch_data[i].pch_adapter.dev.parent = &pdev->dev;
> > +
> > + ret = i2c_add_adapter(&(adap_info->pch_data[i].pch_adapter));
> > +
> > + if (ret) {
> > + pch_pci_err(pdev, "i2c_add_adapter FAILED\n");
> > + goto err_i2c_add_adapter;
> > + }
> > +
> > + pch_init(&adap_info->pch_data[i]);
> > + ret = request_irq(pdev->irq, pch_handler_list[i], IRQF_SHARED,
> > + KBUILD_MODNAME, &adap_info->pch_data[i]);
> > + if (ret) {
> > + pch_pci_err(pdev, "request_irq FAILED\n");
> > + goto err_request_irq;
> > + }
> > + }
> > +
> > + pci_set_drvdata(pdev, adap_info);
> > + pch_pci_dbg(pdev, "returns %d.\n", ret);
> > + return 0;
> > +
> > +err_request_irq:
> > + for (i = 0; i < PCH_MAX_CHN; i++)
> > + i2c_del_adapter(&(adap_info->pch_data[i].pch_adapter));
> > +err_i2c_add_adapter:
> > + pci_iounmap(pdev, base_addr);
> > +err_pci_iomap:
> > + pci_release_regions(pdev);
> > +err_pci_req:
> > + pci_disable_device(pdev);
> > +err_pci_enable:
> > + kfree(adap_info);
> > + return ret;
> > +}
> > +
> > +static void __devexit pch_remove(struct pci_dev *pdev)
> > +{
> > + int i;
> > +
> > + struct adapter_info *adap_info = pci_get_drvdata(pdev);
>
> no need for the blank line.
>
> > +
> > +
> > + for (i = 0; i < PCH_MAX_CHN; i++) {
> > + pch_disbl_int(&adap_info->pch_data[i]);
> > + free_irq(pdev->irq, &adap_info->pch_data[i]);
> > + i2c_del_adapter(&(adap_info->pch_data[i].pch_adapter));
> > + }
> > +
> > + if (adap_info->pch_data[0].pch_base_address) {
> > + pci_iounmap(pdev, adap_info->pch_data[0].pch_base_address);
> > + adap_info->pch_data[0].pch_base_address = 0;
> > + }
> > +
> > + pci_set_drvdata(pdev, NULL);
> > +
> > + pci_release_regions(pdev);
> > +
> > + pci_disable_device(pdev);
> > + kfree(adap_info);
> > +}
> > +
> > +#ifdef CONFIG_PM
> > +static int pch_suspend(struct pci_dev *pdev, pm_message_t state)
> > +{
> > + int i;
> > + int ret;
> > +
> > + struct adapter_info *adap_info = pci_get_drvdata(pdev);
> > + void __iomem *p = adap_info->pch_data[0].pch_base_address;
> >
> again, blank line, also see notes on ordering.
>
> > + adap_info->pch_suspended = true;
> > +
> > + for (i = 0; i < PCH_MAX_CHN; i++) {
> > + while ((adap_info->pch_data[i].pch_xfer_in_progress)) {
> > + /* Wait until all channel transfers are completed */
> > + msleep(1);
> > + }
> > + /* Disable the i2c interrupts */
> > + pch_disbl_int(&adap_info->pch_data[i]);
> > + }
> > +
> > + pch_pci_dbg(pdev, "I2CSR = %x I2CBUFSTA = %x I2CESRSTA = %x "
> > + "invoked function pch_disbl_int successfully\n",
> > + ioread32(p + 0x08), ioread32(p + 0x30), ioread32(p + 0x44));
>
> magic numbers being used to ioread32?
>
> > + ret = pci_save_state(pdev);
> > +
> > + if (ret) {
> > + pch_pci_err(pdev, "pci_save_state\n");
> > + return ret;
> > + }
> > +
> > + pci_enable_wake(pdev, PCI_D3hot, 0);
> > + pci_disable_device(pdev);
> > + pci_set_power_state(pdev, pci_choose_state(pdev, state));
> > +
> > + return 0;
> > +}
> > +
> > +static int pch_resume(struct pci_dev *pdev)
> > +{
> > + struct adapter_info *adap_info = pci_get_drvdata(pdev);
> > + int i;
> > +
> > + pci_set_power_state(pdev, PCI_D0);
> > + pci_restore_state(pdev);
> > +
> > + if (pci_enable_device(pdev) < 0) {
> > + pch_pci_err(pdev, "pci_enable_device FAILED in pch_resume\n");
> > + return -EIO;
> > + }
> > +
> > + pci_enable_wake(pdev, PCI_D3hot, 0);
> > +
> > + for (i = 0; i < PCH_MAX_CHN; i++)
> > + pch_init(&adap_info->pch_data[i]);
> > +
> > + adap_info->pch_suspended = false;
> > +
> > + return 0;
> > +}
> > +#else
> > +#define pch_suspend NULL
> > +#define pch_resume NULL
> > +#endif
> > +
> > +static struct pci_driver pch_pcidriver = {
> > + .name = KBUILD_MODNAME,
> > + .id_table = pch_pcidev_id,
> > + .probe = pch_probe,
> > + .remove = __devexit_p(pch_remove),
> > + .suspend = pch_suspend,
> > + .resume = pch_resume
> > +};
> > +
> > +static int __init pch_pci_init(void)
> > +{
> > + return pci_register_driver(&pch_pcidriver);
> > +}
> > +
> > +static void __exit pch_pci_exit(void)
> > +{
> > + pci_unregister_driver(&pch_pcidriver);
> > +}
> > +
> > +MODULE_DESCRIPTION("PCH I2C PCI Driver");
> > +MODULE_LICENSE("GPL");
>
> no MODULE_AUTHOR?
>
> > +module_init(pch_pci_init);
> > +module_exit(pch_pci_exit);
> > +module_param(pch_i2c_speed, int, (S_IRUSR | S_IWUSR));
> > +module_param(pch_clk, int, (S_IRUSR | S_IWUSR));
>

Thanks, Ohtake(OKISemi)




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