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linux/drivers/i2c/busses/i2c-eg20t.c
Yadi.hu 371a015344 i2c-eg20t: fix race between i2c init and interrupt enable 
the eg20t driver call request_irq() function before the pch_base_address,
base address of i2c controller's register, is assigned an effective value.

there is one possible scenario that an interrupt which isn't inside eg20t
arrives immediately after request_irq() is executed when i2c controller
shares an interrupt number with others. since the interrupt handler
pch_i2c_handler() has already active as shared action, it will be called
and read its own register to determine if this interrupt is from itself.

At that moment, since base address of i2c registers is not remapped
in kernel space yet,so the INT handler will access an illegal address
and then a error occurs.

Signed-off-by: Yadi.hu <yadi.hu@windriver.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
2016-09-21 18:07:51 +02:00

941 lines
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/*
* Copyright (C) 2011 LAPIS 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.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.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>
#include <linux/slab.h>
#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_RESTART 0x0004
#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)
/*
Set the number of I2C instance max
Intel EG20T PCH : 1ch
LAPIS Semiconductor ML7213 IOH : 2ch
LAPIS Semiconductor ML7831 IOH : 1ch
*/
#define PCH_I2C_MAX_DEV 2
/**
* struct i2c_algo_pch_data - for I2C driver functionalities
* @pch_adapter: stores the reference to i2c_adapter structure
* @p_adapter_info: stores the reference to adapter_info 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_i2c_xfer_in_progress: specifies whether the transfer is completed
*/
struct i2c_algo_pch_data {
struct i2c_adapter pch_adapter;
struct adapter_info *p_adapter_info;
void __iomem *pch_base_address;
int pch_buff_mode_en;
u32 pch_event_flag;
bool pch_i2c_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_i2c_suspended: specifies whether the system is suspended or not
* perhaps with more lines and words.
* @ch_num: specifies the number of i2c instance
*
* pch_data has as many elements as maximum I2C channels
*/
struct adapter_info {
struct i2c_algo_pch_data pch_data[PCH_I2C_MAX_DEV];
bool pch_i2c_suspended;
int ch_num;
};
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);
/* Definition for ML7213 by LAPIS Semiconductor */
#define PCI_VENDOR_ID_ROHM 0x10DB
#define PCI_DEVICE_ID_ML7213_I2C 0x802D
#define PCI_DEVICE_ID_ML7223_I2C 0x8010
#define PCI_DEVICE_ID_ML7831_I2C 0x8817
static const struct pci_device_id pch_pcidev_id[] = {
{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_PCH_I2C), 1, },
{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_I2C), 2, },
{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_I2C), 1, },
{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_I2C), 1, },
{0,}
};
static irqreturn_t pch_i2c_handler(int irq, void *pData);
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_i2c_init() - hardware initialization of I2C module
* @adap: Pointer to struct i2c_algo_pch_data.
*/
static void pch_i2c_init(struct i2c_algo_pch_data *adap)
{
void __iomem *p = adap->pch_base_address;
u32 pch_i2cbc;
u32 pch_i2ctmr;
u32 reg_value;
/* reset I2C controller */
iowrite32(0x01, p + PCH_I2CSRST);
msleep(20);
iowrite32(0x0, p + PCH_I2CSRST);
/* Initialize I2C registers */
iowrite32(0x21, p + PCH_I2CNF);
pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_I2CCTL_I2CMEN);
if (pch_i2c_speed != 400)
pch_i2c_speed = 100;
reg_value = PCH_I2CCTL_I2CMEN;
if (pch_i2c_speed == FAST_MODE_CLK) {
reg_value |= FAST_MODE_EN;
pch_dbg(adap, "Fast mode enabled\n");
}
if (pch_clk > PCH_MAX_CLK)
pch_clk = 62500;
pch_i2cbc = (pch_clk + (pch_i2c_speed * 4)) / (pch_i2c_speed * 8);
/* 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);
}
/**
* pch_i2c_wait_for_bus_idle() - check the status of bus.
* @adap: Pointer to struct i2c_algo_pch_data.
* @timeout: waiting time counter (ms).
*/
static s32 pch_i2c_wait_for_bus_idle(struct i2c_algo_pch_data *adap,
s32 timeout)
{
void __iomem *p = adap->pch_base_address;
int schedule = 0;
unsigned long end = jiffies + msecs_to_jiffies(timeout);
while (ioread32(p + PCH_I2CSR) & I2CMBB_BIT) {
if (time_after(jiffies, end)) {
pch_dbg(adap, "I2CSR = %x\n", ioread32(p + PCH_I2CSR));
pch_err(adap, "%s: Timeout Error.return%d\n",
__func__, -ETIME);
pch_i2c_init(adap);
return -ETIME;
}
if (!schedule)
/* Retry after some usecs */
udelay(5);
else
/* Wait a bit more without consuming CPU */
usleep_range(20, 1000);
schedule = 1;
}
return 0;
}
/**
* pch_i2c_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_i2c_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);
}
/**
* pch_i2c_stop() - generate stop condition in normal mode.
* @adap: Pointer to struct i2c_algo_pch_data.
*/
static void pch_i2c_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);
}
static int pch_i2c_wait_for_check_xfer(struct i2c_algo_pch_data *adap)
{
long ret;
void __iomem *p = adap->pch_base_address;
ret = wait_event_timeout(pch_event,
(adap->pch_event_flag != 0), msecs_to_jiffies(1000));
if (!ret) {
pch_err(adap, "%s:wait-event timeout\n", __func__);
adap->pch_event_flag = 0;
pch_i2c_stop(adap);
pch_i2c_init(adap);
return -ETIMEDOUT;
}
if (adap->pch_event_flag & I2C_ERROR_MASK) {
pch_err(adap, "Lost Arbitration\n");
adap->pch_event_flag = 0;
pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMAL_BIT);
pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
pch_i2c_init(adap);
return -EAGAIN;
}
adap->pch_event_flag = 0;
if (ioread32(p + PCH_I2CSR) & PCH_GETACK) {
pch_dbg(adap, "Receive NACK for slave address setting\n");
return -ENXIO;
}
return 0;
}
/**
* pch_i2c_repstart() - generate repeated start condition in normal mode
* @adap: Pointer to struct i2c_algo_pch_data.
*/
static void pch_i2c_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_i2c_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_i2c_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;
s32 rtn;
void __iomem *p = adap->pch_base_address;
length = msgs->len;
buf = msgs->buf;
addr = msgs->addr;
/* enable master tx */
pch_setbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
pch_dbg(adap, "I2CCTL = %x msgs->len = %d\n", ioread32(p + PCH_I2CCTL),
length);
if (first) {
if (pch_i2c_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) & 0x06;
iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
if (first)
pch_i2c_start(adap);
rtn = pch_i2c_wait_for_check_xfer(adap);
if (rtn)
return rtn;
addr_8_lsb = (addr & I2C_ADDR_MSK);
iowrite32(addr_8_lsb, p + PCH_I2CDR);
} else {
/* set 7 bit slave address and R/W bit as 0 */
iowrite32(addr << 1, p + PCH_I2CDR);
if (first)
pch_i2c_start(adap);
}
rtn = pch_i2c_wait_for_check_xfer(adap);
if (rtn)
return rtn;
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]);
rtn = pch_i2c_wait_for_check_xfer(adap);
if (rtn)
return rtn;
pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMCF_BIT);
pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
}
/* check if this is the last message */
if (last)
pch_i2c_stop(adap);
else
pch_i2c_repstart(adap);
pch_dbg(adap, "return=%d\n", wrcount);
return wrcount;
}
/**
* pch_i2c_sendack() - send ACK
* @adap: Pointer to struct i2c_algo_pch_data.
*/
static void pch_i2c_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_i2c_sendnack() - send NACK
* @adap: Pointer to struct i2c_algo_pch_data.
*/
static void pch_i2c_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_i2c_restart() - Generate I2C restart condition in normal mode.
* @adap: Pointer to struct i2c_algo_pch_data.
*
* Generate I2C restart condition in normal mode by setting I2CCTL.I2CRSTA.
*/
static void pch_i2c_restart(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_RESTART);
}
/**
* pch_i2c_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.
*/
static s32 pch_i2c_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;
u32 addr_8_lsb;
void __iomem *p = adap->pch_base_address;
s32 rtn;
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_i2c_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);
iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
if (first)
pch_i2c_start(adap);
rtn = pch_i2c_wait_for_check_xfer(adap);
if (rtn)
return rtn;
addr_8_lsb = (addr & I2C_ADDR_MSK);
iowrite32(addr_8_lsb, p + PCH_I2CDR);
pch_i2c_restart(adap);
rtn = pch_i2c_wait_for_check_xfer(adap);
if (rtn)
return rtn;
addr_2_msb |= 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_i2c_start(adap);
rtn = pch_i2c_wait_for_check_xfer(adap);
if (rtn)
return rtn;
if (length == 0) {
pch_i2c_stop(adap);
ioread32(p + PCH_I2CDR); /* Dummy read needs */
count = length;
} else {
int read_index;
int loop;
pch_i2c_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++;
rtn = pch_i2c_wait_for_check_xfer(adap);
if (rtn)
return rtn;
} /* end for */
pch_i2c_sendnack(adap);
buf[read_index] = ioread32(p + PCH_I2CDR); /* Read final - 1 */
if (length != 1)
read_index++;
rtn = pch_i2c_wait_for_check_xfer(adap);
if (rtn)
return rtn;
if (last)
pch_i2c_stop(adap);
else
pch_i2c_repstart(adap);
buf[read_index++] = ioread32(p + PCH_I2CDR); /* Read Final */
count = read_index;
}
return count;
}
/**
* pch_i2c_cb() - Interrupt handler Call back function
* @adap: Pointer to struct i2c_algo_pch_data.
*/
static void pch_i2c_cb(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 (sts & I2CMAL_BIT)
adap->pch_event_flag |= I2CMAL_EVENT;
if (sts & I2CMCF_BIT)
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(&pch_event);
}
/**
* pch_i2c_handler() - interrupt handler for the PCH I2C controller
* @irq: irq number.
* @pData: cookie passed back to the handler function.
*/
static irqreturn_t pch_i2c_handler(int irq, void *pData)
{
u32 reg_val;
int flag;
int i;
struct adapter_info *adap_info = pData;
void __iomem *p;
u32 mode;
for (i = 0, flag = 0; i < adap_info->ch_num; i++) {
p = adap_info->pch_data[i].pch_base_address;
mode = ioread32(p + PCH_I2CMOD);
mode &= BUFFER_MODE | EEPROM_SR_MODE;
if (mode != NORMAL_MODE) {
pch_err(adap_info->pch_data,
"I2C-%d mode(%d) is not supported\n", mode, i);
continue;
}
reg_val = ioread32(p + PCH_I2CSR);
if (reg_val & (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT)) {
pch_i2c_cb(&adap_info->pch_data[i]);
flag = 1;
}
}
return flag ? IRQ_HANDLED : IRQ_NONE;
}
/**
* pch_i2c_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_i2c_xfer(struct i2c_adapter *i2c_adap,
struct i2c_msg *msgs, s32 num)
{
struct i2c_msg *pmsg;
u32 i = 0;
u32 status;
s32 ret;
struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
ret = mutex_lock_interruptible(&pch_mutex);
if (ret)
return ret;
if (adap->p_adapter_info->pch_i2c_suspended) {
mutex_unlock(&pch_mutex);
return -EBUSY;
}
pch_dbg(adap, "adap->p_adapter_info->pch_i2c_suspended is %d\n",
adap->p_adapter_info->pch_i2c_suspended);
/* transfer not completed */
adap->pch_i2c_xfer_in_progress = true;
for (i = 0; i < num && ret >= 0; 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);
if ((status & (I2C_M_RD)) != false) {
ret = pch_i2c_readbytes(i2c_adap, pmsg, (i + 1 == num),
(i == 0));
} else {
ret = pch_i2c_writebytes(i2c_adap, pmsg, (i + 1 == num),
(i == 0));
}
}
adap->pch_i2c_xfer_in_progress = false; /* transfer completed */
mutex_unlock(&pch_mutex);
return (ret < 0) ? ret : num;
}
/**
* pch_i2c_func() - return the functionality of the I2C driver
* @adap: Pointer to struct i2c_algo_pch_data.
*/
static u32 pch_i2c_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
}
static struct i2c_algorithm pch_algorithm = {
.master_xfer = pch_i2c_xfer,
.functionality = pch_i2c_func
};
/**
* pch_i2c_disbl_int() - Disable PCH I2C interrupts
* @adap: Pointer to struct i2c_algo_pch_data.
*/
static void pch_i2c_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 pch_i2c_probe(struct pci_dev *pdev,
const struct pci_device_id *id)
{
void __iomem *base_addr;
int ret;
int i, j;
struct adapter_info *adap_info;
struct i2c_adapter *pch_adap;
pch_pci_dbg(pdev, "Entered.\n");
adap_info = kzalloc((sizeof(struct adapter_info)), GFP_KERNEL);
if (adap_info == NULL)
return -ENOMEM;
ret = pci_enable_device(pdev);
if (ret) {
pch_pci_err(pdev, "pci_enable_device FAILED\n");
goto err_pci_enable;
}
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 == NULL) {
pch_pci_err(pdev, "pci_iomap FAILED\n");
ret = -ENOMEM;
goto err_pci_iomap;
}
/* Set the number of I2C channel instance */
adap_info->ch_num = id->driver_data;
for (i = 0; i < adap_info->ch_num; i++) {
pch_adap = &adap_info->pch_data[i].pch_adapter;
adap_info->pch_i2c_suspended = false;
adap_info->pch_data[i].p_adapter_info = adap_info;
pch_adap->owner = THIS_MODULE;
pch_adap->class = I2C_CLASS_HWMON;
strlcpy(pch_adap->name, KBUILD_MODNAME, sizeof(pch_adap->name));
pch_adap->algo = &pch_algorithm;
pch_adap->algo_data = &adap_info->pch_data[i];
/* base_addr + offset; */
adap_info->pch_data[i].pch_base_address = base_addr + 0x100 * i;
pch_adap->dev.of_node = pdev->dev.of_node;
pch_adap->dev.parent = &pdev->dev;
}
ret = request_irq(pdev->irq, pch_i2c_handler, IRQF_SHARED,
KBUILD_MODNAME, adap_info);
if (ret) {
pch_pci_err(pdev, "request_irq FAILED\n");
goto err_request_irq;
}
for (i = 0; i < adap_info->ch_num; i++) {
pch_adap = &adap_info->pch_data[i].pch_adapter;
pch_i2c_init(&adap_info->pch_data[i]);
pch_adap->nr = i;
ret = i2c_add_numbered_adapter(pch_adap);
if (ret) {
pch_pci_err(pdev, "i2c_add_adapter[ch:%d] FAILED\n", i);
goto err_add_adapter;
}
}
pci_set_drvdata(pdev, adap_info);
pch_pci_dbg(pdev, "returns %d.\n", ret);
return 0;
err_add_adapter:
for (j = 0; j < i; j++)
i2c_del_adapter(&adap_info->pch_data[j].pch_adapter);
free_irq(pdev->irq, adap_info);
err_request_irq:
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 pch_i2c_remove(struct pci_dev *pdev)
{
int i;
struct adapter_info *adap_info = pci_get_drvdata(pdev);
free_irq(pdev->irq, adap_info);
for (i = 0; i < adap_info->ch_num; i++) {
pch_i2c_disbl_int(&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);
for (i = 0; i < adap_info->ch_num; i++)
adap_info->pch_data[i].pch_base_address = NULL;
pci_release_regions(pdev);
pci_disable_device(pdev);
kfree(adap_info);
}
#ifdef CONFIG_PM
static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
{
int ret;
int i;
struct adapter_info *adap_info = pci_get_drvdata(pdev);
void __iomem *p = adap_info->pch_data[0].pch_base_address;
adap_info->pch_i2c_suspended = true;
for (i = 0; i < adap_info->ch_num; i++) {
while ((adap_info->pch_data[i].pch_i2c_xfer_in_progress)) {
/* Wait until all channel transfers are completed */
msleep(20);
}
}
/* Disable the i2c interrupts */
for (i = 0; i < adap_info->ch_num; i++)
pch_i2c_disbl_int(&adap_info->pch_data[i]);
pch_pci_dbg(pdev, "I2CSR = %x I2CBUFSTA = %x I2CESRSTA = %x "
"invoked function pch_i2c_disbl_int successfully\n",
ioread32(p + PCH_I2CSR), ioread32(p + PCH_I2CBUFSTA),
ioread32(p + PCH_I2CESRSTA));
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_i2c_resume(struct pci_dev *pdev)
{
int i;
struct adapter_info *adap_info = pci_get_drvdata(pdev);
pci_set_power_state(pdev, PCI_D0);
pci_restore_state(pdev);
if (pci_enable_device(pdev) < 0) {
pch_pci_err(pdev, "pch_i2c_resume:pci_enable_device FAILED\n");
return -EIO;
}
pci_enable_wake(pdev, PCI_D3hot, 0);
for (i = 0; i < adap_info->ch_num; i++)
pch_i2c_init(&adap_info->pch_data[i]);
adap_info->pch_i2c_suspended = false;
return 0;
}
#else
#define pch_i2c_suspend NULL
#define pch_i2c_resume NULL
#endif
static struct pci_driver pch_pcidriver = {
.name = KBUILD_MODNAME,
.id_table = pch_pcidev_id,
.probe = pch_i2c_probe,
.remove = pch_i2c_remove,
.suspend = pch_i2c_suspend,
.resume = pch_i2c_resume
};
module_pci_driver(pch_pcidriver);
MODULE_DESCRIPTION("Intel EG20T PCH/LAPIS Semico ML7213/ML7223/ML7831 IOH I2C");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Tomoya MORINAGA. <tomoya.rohm@gmail.com>");
module_param(pch_i2c_speed, int, (S_IRUSR | S_IWUSR));
module_param(pch_clk, int, (S_IRUSR | S_IWUSR));
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