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d60ece5f01
linux/drivers/i2c/busses/i2c-omap.c
Felipe Balbi d60ece5f01 i2c: omap: ensure writes to dev->buf_len are ordered 
if we allow compiler reorder our writes, we could
fall into a situation where dev->buf_len is reset
for no apparent reason.

This bug was found with a simple script which would
transfer data to an i2c client from 1 to 1024 bytes
(a simple for loop), when we got to transfer sizes
bigger than the fifo size, dev->buf_len was reset
to zero before we had an oportunity to handle XDR
Interrupt. Because dev->buf_len was zero, we entered
omap_i2c_transmit_data() to transfer zero bytes,
which would mean we would just silently exit
omap_i2c_transmit_data() without actually writing
anything to DATA register. That would cause XDR
IRQ to trigger forever and we would never transfer
the remaining bytes.

After adding the memory barrier, we also drop resetting
dev->buf_len to zero in omap_i2c_xfer_msg() because
both omap_i2c_transmit_data() and omap_i2c_receive_data()
will act until dev->buf_len reaches zero, rendering the
other write in omap_i2c_xfer_msg() redundant.

This patch has been tested with pandaboard for a few
iterations of the script mentioned above.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-14 17:44:37 +01:00

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/*
* TI OMAP I2C master mode driver
*
* Copyright (C) 2003 MontaVista Software, Inc.
* Copyright (C) 2005 Nokia Corporation
* Copyright (C) 2004 - 2007 Texas Instruments.
*
* Originally written by MontaVista Software, Inc.
* Additional contributions by:
* Tony Lindgren <tony@atomide.com>
* Imre Deak <imre.deak@nokia.com>
* Juha Yrjölä <juha.yrjola@solidboot.com>
* Syed Khasim <x0khasim@ti.com>
* Nishant Menon <nm@ti.com>
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/completion.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_i2c.h>
#include <linux/of_device.h>
#include <linux/slab.h>
#include <linux/i2c-omap.h>
#include <linux/pm_runtime.h>
/* I2C controller revisions */
#define OMAP_I2C_OMAP1_REV_2 0x20
/* I2C controller revisions present on specific hardware */
#define OMAP_I2C_REV_ON_2430 0x36
#define OMAP_I2C_REV_ON_3430_3530 0x3C
#define OMAP_I2C_REV_ON_3630_4430 0x40
/* timeout waiting for the controller to respond */
#define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
/* timeout for pm runtime autosuspend */
#define OMAP_I2C_PM_TIMEOUT 1000 /* ms */
/* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
enum {
OMAP_I2C_REV_REG = 0,
OMAP_I2C_IE_REG,
OMAP_I2C_STAT_REG,
OMAP_I2C_IV_REG,
OMAP_I2C_WE_REG,
OMAP_I2C_SYSS_REG,
OMAP_I2C_BUF_REG,
OMAP_I2C_CNT_REG,
OMAP_I2C_DATA_REG,
OMAP_I2C_SYSC_REG,
OMAP_I2C_CON_REG,
OMAP_I2C_OA_REG,
OMAP_I2C_SA_REG,
OMAP_I2C_PSC_REG,
OMAP_I2C_SCLL_REG,
OMAP_I2C_SCLH_REG,
OMAP_I2C_SYSTEST_REG,
OMAP_I2C_BUFSTAT_REG,
/* only on OMAP4430 */
OMAP_I2C_IP_V2_REVNB_LO,
OMAP_I2C_IP_V2_REVNB_HI,
OMAP_I2C_IP_V2_IRQSTATUS_RAW,
OMAP_I2C_IP_V2_IRQENABLE_SET,
OMAP_I2C_IP_V2_IRQENABLE_CLR,
};
/* I2C Interrupt Enable Register (OMAP_I2C_IE): */
#define OMAP_I2C_IE_XDR (1 << 14) /* TX Buffer drain int enable */
#define OMAP_I2C_IE_RDR (1 << 13) /* RX Buffer drain int enable */
#define OMAP_I2C_IE_XRDY (1 << 4) /* TX data ready int enable */
#define OMAP_I2C_IE_RRDY (1 << 3) /* RX data ready int enable */
#define OMAP_I2C_IE_ARDY (1 << 2) /* Access ready int enable */
#define OMAP_I2C_IE_NACK (1 << 1) /* No ack interrupt enable */
#define OMAP_I2C_IE_AL (1 << 0) /* Arbitration lost int ena */
/* I2C Status Register (OMAP_I2C_STAT): */
#define OMAP_I2C_STAT_XDR (1 << 14) /* TX Buffer draining */
#define OMAP_I2C_STAT_RDR (1 << 13) /* RX Buffer draining */
#define OMAP_I2C_STAT_BB (1 << 12) /* Bus busy */
#define OMAP_I2C_STAT_ROVR (1 << 11) /* Receive overrun */
#define OMAP_I2C_STAT_XUDF (1 << 10) /* Transmit underflow */
#define OMAP_I2C_STAT_AAS (1 << 9) /* Address as slave */
#define OMAP_I2C_STAT_AD0 (1 << 8) /* Address zero */
#define OMAP_I2C_STAT_XRDY (1 << 4) /* Transmit data ready */
#define OMAP_I2C_STAT_RRDY (1 << 3) /* Receive data ready */
#define OMAP_I2C_STAT_ARDY (1 << 2) /* Register access ready */
#define OMAP_I2C_STAT_NACK (1 << 1) /* No ack interrupt enable */
#define OMAP_I2C_STAT_AL (1 << 0) /* Arbitration lost int ena */
/* I2C WE wakeup enable register */
#define OMAP_I2C_WE_XDR_WE (1 << 14) /* TX drain wakup */
#define OMAP_I2C_WE_RDR_WE (1 << 13) /* RX drain wakeup */
#define OMAP_I2C_WE_AAS_WE (1 << 9) /* Address as slave wakeup*/
#define OMAP_I2C_WE_BF_WE (1 << 8) /* Bus free wakeup */
#define OMAP_I2C_WE_STC_WE (1 << 6) /* Start condition wakeup */
#define OMAP_I2C_WE_GC_WE (1 << 5) /* General call wakeup */
#define OMAP_I2C_WE_DRDY_WE (1 << 3) /* TX/RX data ready wakeup */
#define OMAP_I2C_WE_ARDY_WE (1 << 2) /* Reg access ready wakeup */
#define OMAP_I2C_WE_NACK_WE (1 << 1) /* No acknowledgment wakeup */
#define OMAP_I2C_WE_AL_WE (1 << 0) /* Arbitration lost wakeup */
#define OMAP_I2C_WE_ALL (OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \
OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \
OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \
OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \
OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE)
/* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
#define OMAP_I2C_BUF_RDMA_EN (1 << 15) /* RX DMA channel enable */
#define OMAP_I2C_BUF_RXFIF_CLR (1 << 14) /* RX FIFO Clear */
#define OMAP_I2C_BUF_XDMA_EN (1 << 7) /* TX DMA channel enable */
#define OMAP_I2C_BUF_TXFIF_CLR (1 << 6) /* TX FIFO Clear */
/* I2C Configuration Register (OMAP_I2C_CON): */
#define OMAP_I2C_CON_EN (1 << 15) /* I2C module enable */
#define OMAP_I2C_CON_BE (1 << 14) /* Big endian mode */
#define OMAP_I2C_CON_OPMODE_HS (1 << 12) /* High Speed support */
#define OMAP_I2C_CON_STB (1 << 11) /* Start byte mode (master) */
#define OMAP_I2C_CON_MST (1 << 10) /* Master/slave mode */
#define OMAP_I2C_CON_TRX (1 << 9) /* TX/RX mode (master only) */
#define OMAP_I2C_CON_XA (1 << 8) /* Expand address */
#define OMAP_I2C_CON_RM (1 << 2) /* Repeat mode (master only) */
#define OMAP_I2C_CON_STP (1 << 1) /* Stop cond (master only) */
#define OMAP_I2C_CON_STT (1 << 0) /* Start condition (master) */
/* I2C SCL time value when Master */
#define OMAP_I2C_SCLL_HSSCLL 8
#define OMAP_I2C_SCLH_HSSCLH 8
/* I2C System Test Register (OMAP_I2C_SYSTEST): */
#ifdef DEBUG
#define OMAP_I2C_SYSTEST_ST_EN (1 << 15) /* System test enable */
#define OMAP_I2C_SYSTEST_FREE (1 << 14) /* Free running mode */
#define OMAP_I2C_SYSTEST_TMODE_MASK (3 << 12) /* Test mode select */
#define OMAP_I2C_SYSTEST_TMODE_SHIFT (12) /* Test mode select */
#define OMAP_I2C_SYSTEST_SCL_I (1 << 3) /* SCL line sense in */
#define OMAP_I2C_SYSTEST_SCL_O (1 << 2) /* SCL line drive out */
#define OMAP_I2C_SYSTEST_SDA_I (1 << 1) /* SDA line sense in */
#define OMAP_I2C_SYSTEST_SDA_O (1 << 0) /* SDA line drive out */
#endif
/* OCP_SYSSTATUS bit definitions */
#define SYSS_RESETDONE_MASK (1 << 0)
/* OCP_SYSCONFIG bit definitions */
#define SYSC_CLOCKACTIVITY_MASK (0x3 << 8)
#define SYSC_SIDLEMODE_MASK (0x3 << 3)
#define SYSC_ENAWAKEUP_MASK (1 << 2)
#define SYSC_SOFTRESET_MASK (1 << 1)
#define SYSC_AUTOIDLE_MASK (1 << 0)
#define SYSC_IDLEMODE_SMART 0x2
#define SYSC_CLOCKACTIVITY_FCLK 0x2
/* Errata definitions */
#define I2C_OMAP_ERRATA_I207 (1 << 0)
#define I2C_OMAP_ERRATA_I462 (1 << 1)
struct omap_i2c_dev {
spinlock_t lock; /* IRQ synchronization */
struct device *dev;
void __iomem *base; /* virtual */
int irq;
int reg_shift; /* bit shift for I2C register addresses */
struct completion cmd_complete;
struct resource *ioarea;
u32 latency; /* maximum mpu wkup latency */
void (*set_mpu_wkup_lat)(struct device *dev,
long latency);
u32 speed; /* Speed of bus in kHz */
u32 dtrev; /* extra revision from DT */
u32 flags;
u16 cmd_err;
u8 *buf;
u8 *regs;
size_t buf_len;
struct i2c_adapter adapter;
u8 threshold;
u8 fifo_size; /* use as flag and value
* fifo_size==0 implies no fifo
* if set, should be trsh+1
*/
u8 rev;
unsigned b_hw:1; /* bad h/w fixes */
unsigned receiver:1; /* true when we're in receiver mode */
u16 iestate; /* Saved interrupt register */
u16 pscstate;
u16 scllstate;
u16 sclhstate;
u16 bufstate;
u16 syscstate;
u16 westate;
u16 errata;
};
static const u8 reg_map_ip_v1[] = {
[OMAP_I2C_REV_REG] = 0x00,
[OMAP_I2C_IE_REG] = 0x01,
[OMAP_I2C_STAT_REG] = 0x02,
[OMAP_I2C_IV_REG] = 0x03,
[OMAP_I2C_WE_REG] = 0x03,
[OMAP_I2C_SYSS_REG] = 0x04,
[OMAP_I2C_BUF_REG] = 0x05,
[OMAP_I2C_CNT_REG] = 0x06,
[OMAP_I2C_DATA_REG] = 0x07,
[OMAP_I2C_SYSC_REG] = 0x08,
[OMAP_I2C_CON_REG] = 0x09,
[OMAP_I2C_OA_REG] = 0x0a,
[OMAP_I2C_SA_REG] = 0x0b,
[OMAP_I2C_PSC_REG] = 0x0c,
[OMAP_I2C_SCLL_REG] = 0x0d,
[OMAP_I2C_SCLH_REG] = 0x0e,
[OMAP_I2C_SYSTEST_REG] = 0x0f,
[OMAP_I2C_BUFSTAT_REG] = 0x10,
};
static const u8 reg_map_ip_v2[] = {
[OMAP_I2C_REV_REG] = 0x04,
[OMAP_I2C_IE_REG] = 0x2c,
[OMAP_I2C_STAT_REG] = 0x28,
[OMAP_I2C_IV_REG] = 0x34,
[OMAP_I2C_WE_REG] = 0x34,
[OMAP_I2C_SYSS_REG] = 0x90,
[OMAP_I2C_BUF_REG] = 0x94,
[OMAP_I2C_CNT_REG] = 0x98,
[OMAP_I2C_DATA_REG] = 0x9c,
[OMAP_I2C_SYSC_REG] = 0x10,
[OMAP_I2C_CON_REG] = 0xa4,
[OMAP_I2C_OA_REG] = 0xa8,
[OMAP_I2C_SA_REG] = 0xac,
[OMAP_I2C_PSC_REG] = 0xb0,
[OMAP_I2C_SCLL_REG] = 0xb4,
[OMAP_I2C_SCLH_REG] = 0xb8,
[OMAP_I2C_SYSTEST_REG] = 0xbC,
[OMAP_I2C_BUFSTAT_REG] = 0xc0,
[OMAP_I2C_IP_V2_REVNB_LO] = 0x00,
[OMAP_I2C_IP_V2_REVNB_HI] = 0x04,
[OMAP_I2C_IP_V2_IRQSTATUS_RAW] = 0x24,
[OMAP_I2C_IP_V2_IRQENABLE_SET] = 0x2c,
[OMAP_I2C_IP_V2_IRQENABLE_CLR] = 0x30,
};
static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
int reg, u16 val)
{
__raw_writew(val, i2c_dev->base +
(i2c_dev->regs[reg] << i2c_dev->reg_shift));
}
static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
{
return __raw_readw(i2c_dev->base +
(i2c_dev->regs[reg] << i2c_dev->reg_shift));
}
static int omap_i2c_init(struct omap_i2c_dev *dev)
{
u16 psc = 0, scll = 0, sclh = 0, buf = 0;
u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
unsigned long fclk_rate = 12000000;
unsigned long timeout;
unsigned long internal_clk = 0;
struct clk *fclk;
if (dev->rev >= OMAP_I2C_OMAP1_REV_2) {
/* Disable I2C controller before soft reset */
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
omap_i2c_read_reg(dev, OMAP_I2C_CON_REG) &
~(OMAP_I2C_CON_EN));
omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
/* For some reason we need to set the EN bit before the
* reset done bit gets set. */
timeout = jiffies + OMAP_I2C_TIMEOUT;
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) &
SYSS_RESETDONE_MASK)) {
if (time_after(jiffies, timeout)) {
dev_warn(dev->dev, "timeout waiting "
"for controller reset\n");
return -ETIMEDOUT;
}
msleep(1);
}
/* SYSC register is cleared by the reset; rewrite it */
if (dev->rev == OMAP_I2C_REV_ON_2430) {
omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
SYSC_AUTOIDLE_MASK);
} else if (dev->rev >= OMAP_I2C_REV_ON_3430_3530) {
dev->syscstate = SYSC_AUTOIDLE_MASK;
dev->syscstate |= SYSC_ENAWAKEUP_MASK;
dev->syscstate |= (SYSC_IDLEMODE_SMART <<
__ffs(SYSC_SIDLEMODE_MASK));
dev->syscstate |= (SYSC_CLOCKACTIVITY_FCLK <<
__ffs(SYSC_CLOCKACTIVITY_MASK));
omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
dev->syscstate);
/*
* Enabling all wakup sources to stop I2C freezing on
* WFI instruction.
* REVISIT: Some wkup sources might not be needed.
*/
dev->westate = OMAP_I2C_WE_ALL;
omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
dev->westate);
}
}
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
if (dev->flags & OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK) {
/*
* The I2C functional clock is the armxor_ck, so there's
* no need to get "armxor_ck" separately. Now, if OMAP2420
* always returns 12MHz for the functional clock, we can
* do this bit unconditionally.
*/
fclk = clk_get(dev->dev, "fck");
fclk_rate = clk_get_rate(fclk);
clk_put(fclk);
/* TRM for 5912 says the I2C clock must be prescaled to be
* between 7 - 12 MHz. The XOR input clock is typically
* 12, 13 or 19.2 MHz. So we should have code that produces:
*
* XOR MHz Divider Prescaler
* 12 1 0
* 13 2 1
* 19.2 2 1
*/
if (fclk_rate > 12000000)
psc = fclk_rate / 12000000;
}
if (!(dev->flags & OMAP_I2C_FLAG_SIMPLE_CLOCK)) {
/*
* HSI2C controller internal clk rate should be 19.2 Mhz for
* HS and for all modes on 2430. On 34xx we can use lower rate
* to get longer filter period for better noise suppression.
* The filter is iclk (fclk for HS) period.
*/
if (dev->speed > 400 ||
dev->flags & OMAP_I2C_FLAG_FORCE_19200_INT_CLK)
internal_clk = 19200;
else if (dev->speed > 100)
internal_clk = 9600;
else
internal_clk = 4000;
fclk = clk_get(dev->dev, "fck");
fclk_rate = clk_get_rate(fclk) / 1000;
clk_put(fclk);
/* Compute prescaler divisor */
psc = fclk_rate / internal_clk;
psc = psc - 1;
/* If configured for High Speed */
if (dev->speed > 400) {
unsigned long scl;
/* For first phase of HS mode */
scl = internal_clk / 400;
fsscll = scl - (scl / 3) - 7;
fssclh = (scl / 3) - 5;
/* For second phase of HS mode */
scl = fclk_rate / dev->speed;
hsscll = scl - (scl / 3) - 7;
hssclh = (scl / 3) - 5;
} else if (dev->speed > 100) {
unsigned long scl;
/* Fast mode */
scl = internal_clk / dev->speed;
fsscll = scl - (scl / 3) - 7;
fssclh = (scl / 3) - 5;
} else {
/* Standard mode */
fsscll = internal_clk / (dev->speed * 2) - 7;
fssclh = internal_clk / (dev->speed * 2) - 5;
}
scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll;
sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh;
} else {
/* Program desired operating rate */
fclk_rate /= (psc + 1) * 1000;
if (psc > 2)
psc = 2;
scll = fclk_rate / (dev->speed * 2) - 7 + psc;
sclh = fclk_rate / (dev->speed * 2) - 7 + psc;
}
/* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc);
/* SCL low and high time values */
omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, scll);
omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, sclh);
/* Take the I2C module out of reset: */
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
/* Enable interrupts */
dev->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
OMAP_I2C_IE_AL) | ((dev->fifo_size) ?
(OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0);
omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
if (dev->flags & OMAP_I2C_FLAG_RESET_REGS_POSTIDLE) {
dev->pscstate = psc;
dev->scllstate = scll;
dev->sclhstate = sclh;
dev->bufstate = buf;
}
return 0;
}
/*
* Waiting on Bus Busy
*/
static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
{
unsigned long timeout;
timeout = jiffies + OMAP_I2C_TIMEOUT;
while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
if (time_after(jiffies, timeout)) {
dev_warn(dev->dev, "timeout waiting for bus ready\n");
return -ETIMEDOUT;
}
msleep(1);
}
return 0;
}
static void omap_i2c_resize_fifo(struct omap_i2c_dev *dev, u8 size, bool is_rx)
{
u16 buf;
if (dev->flags & OMAP_I2C_FLAG_NO_FIFO)
return;
/*
* Set up notification threshold based on message size. We're doing
* this to try and avoid draining feature as much as possible. Whenever
* we have big messages to transfer (bigger than our total fifo size)
* then we might use draining feature to transfer the remaining bytes.
*/
dev->threshold = clamp(size, (u8) 1, dev->fifo_size);
buf = omap_i2c_read_reg(dev, OMAP_I2C_BUF_REG);
if (is_rx) {
/* Clear RX Threshold */
buf &= ~(0x3f << 8);
buf |= ((dev->threshold - 1) << 8) | OMAP_I2C_BUF_RXFIF_CLR;
} else {
/* Clear TX Threshold */
buf &= ~0x3f;
buf |= (dev->threshold - 1) | OMAP_I2C_BUF_TXFIF_CLR;
}
omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf);
if (dev->rev < OMAP_I2C_REV_ON_3630_4430)
dev->b_hw = 1; /* Enable hardware fixes */
/* calculate wakeup latency constraint for MPU */
if (dev->set_mpu_wkup_lat != NULL)
dev->latency = (1000000 * dev->threshold) /
(1000 * dev->speed / 8);
}
/*
* Low level master read/write transaction.
*/
static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
struct i2c_msg *msg, int stop)
{
struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
unsigned long timeout;
u16 w;
dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
msg->addr, msg->len, msg->flags, stop);
if (msg->len == 0)
return -EINVAL;
dev->receiver = !!(msg->flags & I2C_M_RD);
omap_i2c_resize_fifo(dev, msg->len, dev->receiver);
omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr);
/* REVISIT: Could the STB bit of I2C_CON be used with probing? */
dev->buf = msg->buf;
dev->buf_len = msg->len;
/* make sure writes to dev->buf_len are ordered */
barrier();
omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len);
/* Clear the FIFO Buffers */
w = omap_i2c_read_reg(dev, OMAP_I2C_BUF_REG);
w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, w);
INIT_COMPLETION(dev->cmd_complete);
dev->cmd_err = 0;
w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
/* High speed configuration */
if (dev->speed > 400)
w |= OMAP_I2C_CON_OPMODE_HS;
if (msg->flags & I2C_M_STOP)
stop = 1;
if (msg->flags & I2C_M_TEN)
w |= OMAP_I2C_CON_XA;
if (!(msg->flags & I2C_M_RD))
w |= OMAP_I2C_CON_TRX;
if (!dev->b_hw && stop)
w |= OMAP_I2C_CON_STP;
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
/*
* Don't write stt and stp together on some hardware.
*/
if (dev->b_hw && stop) {
unsigned long delay = jiffies + OMAP_I2C_TIMEOUT;
u16 con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
while (con & OMAP_I2C_CON_STT) {
con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
/* Let the user know if i2c is in a bad state */
if (time_after(jiffies, delay)) {
dev_err(dev->dev, "controller timed out "
"waiting for start condition to finish\n");
return -ETIMEDOUT;
}
cpu_relax();
}
w |= OMAP_I2C_CON_STP;
w &= ~OMAP_I2C_CON_STT;
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
}
/*
* REVISIT: We should abort the transfer on signals, but the bus goes
* into arbitration and we're currently unable to recover from it.
*/
timeout = wait_for_completion_timeout(&dev->cmd_complete,
OMAP_I2C_TIMEOUT);
if (timeout == 0) {
dev_err(dev->dev, "controller timed out\n");
omap_i2c_init(dev);
return -ETIMEDOUT;
}
if (likely(!dev->cmd_err))
return 0;
/* We have an error */
if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
OMAP_I2C_STAT_XUDF)) {
omap_i2c_init(dev);
return -EIO;
}
if (dev->cmd_err & OMAP_I2C_STAT_NACK) {
if (msg->flags & I2C_M_IGNORE_NAK)
return 0;
if (stop) {
w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
w |= OMAP_I2C_CON_STP;
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
}
return -EREMOTEIO;
}
return -EIO;
}
/*
* Prepare controller for a transaction and call omap_i2c_xfer_msg
* to do the work during IRQ processing.
*/
static int
omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
{
struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
int i;
int r;
r = pm_runtime_get_sync(dev->dev);
if (IS_ERR_VALUE(r))
goto out;
r = omap_i2c_wait_for_bb(dev);
if (r < 0)
goto out;
if (dev->set_mpu_wkup_lat != NULL)
dev->set_mpu_wkup_lat(dev->dev, dev->latency);
for (i = 0; i < num; i++) {
r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
if (r != 0)
break;
}
if (dev->set_mpu_wkup_lat != NULL)
dev->set_mpu_wkup_lat(dev->dev, -1);
if (r == 0)
r = num;
omap_i2c_wait_for_bb(dev);
out:
pm_runtime_mark_last_busy(dev->dev);
pm_runtime_put_autosuspend(dev->dev);
return r;
}
static u32
omap_i2c_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
I2C_FUNC_PROTOCOL_MANGLING;
}
static inline void
omap_i2c_complete_cmd(struct omap_i2c_dev *dev, u16 err)
{
dev->cmd_err |= err;
complete(&dev->cmd_complete);
}
static inline void
omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat)
{
omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
}
static inline void i2c_omap_errata_i207(struct omap_i2c_dev *dev, u16 stat)
{
/*
* I2C Errata(Errata Nos. OMAP2: 1.67, OMAP3: 1.8)
* Not applicable for OMAP4.
* Under certain rare conditions, RDR could be set again
* when the bus is busy, then ignore the interrupt and
* clear the interrupt.
*/
if (stat & OMAP_I2C_STAT_RDR) {
/* Step 1: If RDR is set, clear it */
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
/* Step 2: */
if (!(omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG)
& OMAP_I2C_STAT_BB)) {
/* Step 3: */
if (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG)
& OMAP_I2C_STAT_RDR) {
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
dev_dbg(dev->dev, "RDR when bus is busy.\n");
}
}
}
}
/* rev1 devices are apparently only on some 15xx */
#ifdef CONFIG_ARCH_OMAP15XX
static irqreturn_t
omap_i2c_omap1_isr(int this_irq, void *dev_id)
{
struct omap_i2c_dev *dev = dev_id;
u16 iv, w;
if (pm_runtime_suspended(dev->dev))
return IRQ_NONE;
iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
switch (iv) {
case 0x00: /* None */
break;
case 0x01: /* Arbitration lost */
dev_err(dev->dev, "Arbitration lost\n");
omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
break;
case 0x02: /* No acknowledgement */
omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP);
break;
case 0x03: /* Register access ready */
omap_i2c_complete_cmd(dev, 0);
break;
case 0x04: /* Receive data ready */
if (dev->buf_len) {
w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
*dev->buf++ = w;
dev->buf_len--;
if (dev->buf_len) {
*dev->buf++ = w >> 8;
dev->buf_len--;
}
} else
dev_err(dev->dev, "RRDY IRQ while no data requested\n");
break;
case 0x05: /* Transmit data ready */
if (dev->buf_len) {
w = *dev->buf++;
dev->buf_len--;
if (dev->buf_len) {
w |= *dev->buf++ << 8;
dev->buf_len--;
}
omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
} else
dev_err(dev->dev, "XRDY IRQ while no data to send\n");
break;
default:
return IRQ_NONE;
}
return IRQ_HANDLED;
}
#else
#define omap_i2c_omap1_isr NULL
#endif
/*
* OMAP3430 Errata i462: When an XRDY/XDR is hit, wait for XUDF before writing
* data to DATA_REG. Otherwise some data bytes can be lost while transferring
* them from the memory to the I2C interface.
*/
static int errata_omap3_i462(struct omap_i2c_dev *dev)
{
unsigned long timeout = 10000;
u16 stat;
do {
stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
if (stat & OMAP_I2C_STAT_XUDF)
break;
if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_XRDY |
OMAP_I2C_STAT_XDR));
if (stat & OMAP_I2C_STAT_NACK) {
dev->cmd_err |= OMAP_I2C_STAT_NACK;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
}
if (stat & OMAP_I2C_STAT_AL) {
dev_err(dev->dev, "Arbitration lost\n");
dev->cmd_err |= OMAP_I2C_STAT_AL;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
}
return -EIO;
}
cpu_relax();
} while (--timeout);
if (!timeout) {
dev_err(dev->dev, "timeout waiting on XUDF bit\n");
return 0;
}
return 0;
}
static void omap_i2c_receive_data(struct omap_i2c_dev *dev, u8 num_bytes,
bool is_rdr)
{
u16 w;
while (num_bytes--) {
w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
*dev->buf++ = w;
dev->buf_len--;
/*
* Data reg in 2430, omap3 and
* omap4 is 8 bit wide
*/
if (dev->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
*dev->buf++ = w >> 8;
dev->buf_len--;
}
}
}
static int omap_i2c_transmit_data(struct omap_i2c_dev *dev, u8 num_bytes,
bool is_xdr)
{
u16 w;
while (num_bytes--) {
w = *dev->buf++;
dev->buf_len--;
/*
* Data reg in 2430, omap3 and
* omap4 is 8 bit wide
*/
if (dev->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
w |= *dev->buf++ << 8;
dev->buf_len--;
}
if (dev->errata & I2C_OMAP_ERRATA_I462) {
int ret;
ret = errata_omap3_i462(dev);
if (ret < 0)
return ret;
}
omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
}
return 0;
}
static irqreturn_t
omap_i2c_isr(int irq, void *dev_id)
{
struct omap_i2c_dev *dev = dev_id;
irqreturn_t ret = IRQ_HANDLED;
u16 mask;
u16 stat;
spin_lock(&dev->lock);
mask = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
if (stat & mask)
ret = IRQ_WAKE_THREAD;
spin_unlock(&dev->lock);
return ret;
}
static irqreturn_t
omap_i2c_isr_thread(int this_irq, void *dev_id)
{
struct omap_i2c_dev *dev = dev_id;
unsigned long flags;
u16 bits;
u16 stat;
int err = 0, count = 0;
spin_lock_irqsave(&dev->lock, flags);
do {
bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
stat &= bits;
/* If we're in receiver mode, ignore XDR/XRDY */
if (dev->receiver)
stat &= ~(OMAP_I2C_STAT_XDR | OMAP_I2C_STAT_XRDY);
else
stat &= ~(OMAP_I2C_STAT_RDR | OMAP_I2C_STAT_RRDY);
if (!stat) {
/* my work here is done */
goto out;
}
dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
if (count++ == 100) {
dev_warn(dev->dev, "Too much work in one IRQ\n");
break;
}
if (stat & OMAP_I2C_STAT_NACK) {
err |= OMAP_I2C_STAT_NACK;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
break;
}
if (stat & OMAP_I2C_STAT_AL) {
dev_err(dev->dev, "Arbitration lost\n");
err |= OMAP_I2C_STAT_AL;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_AL);
break;
}
/*
* ProDB0017052: Clear ARDY bit twice
*/
if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
OMAP_I2C_STAT_AL)) {
omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_RRDY |
OMAP_I2C_STAT_RDR |
OMAP_I2C_STAT_XRDY |
OMAP_I2C_STAT_XDR |
OMAP_I2C_STAT_ARDY));
break;
}
if (stat & OMAP_I2C_STAT_RDR) {
u8 num_bytes = 1;
if (dev->fifo_size)
num_bytes = dev->buf_len;
omap_i2c_receive_data(dev, num_bytes, true);
if (dev->errata & I2C_OMAP_ERRATA_I207)
i2c_omap_errata_i207(dev, stat);
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
break;
}
if (stat & OMAP_I2C_STAT_RRDY) {
u8 num_bytes = 1;
if (dev->threshold)
num_bytes = dev->threshold;
omap_i2c_receive_data(dev, num_bytes, false);
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RRDY);
continue;
}
if (stat & OMAP_I2C_STAT_XDR) {
u8 num_bytes = 1;
int ret;
if (dev->fifo_size)
num_bytes = dev->buf_len;
ret = omap_i2c_transmit_data(dev, num_bytes, true);
if (ret < 0)
break;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XDR);
break;
}
if (stat & OMAP_I2C_STAT_XRDY) {
u8 num_bytes = 1;
int ret;
if (dev->threshold)
num_bytes = dev->threshold;
ret = omap_i2c_transmit_data(dev, num_bytes, false);
if (ret < 0)
break;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY);
continue;
}
if (stat & OMAP_I2C_STAT_ROVR) {
dev_err(dev->dev, "Receive overrun\n");
err |= OMAP_I2C_STAT_ROVR;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_ROVR);
break;
}
if (stat & OMAP_I2C_STAT_XUDF) {
dev_err(dev->dev, "Transmit underflow\n");
err |= OMAP_I2C_STAT_XUDF;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XUDF);
break;
}
} while (stat);
omap_i2c_complete_cmd(dev, err);
out:
spin_unlock_irqrestore(&dev->lock, flags);
return IRQ_HANDLED;
}
static const struct i2c_algorithm omap_i2c_algo = {
.master_xfer = omap_i2c_xfer,
.functionality = omap_i2c_func,
};
#ifdef CONFIG_OF
static struct omap_i2c_bus_platform_data omap3_pdata = {
.rev = OMAP_I2C_IP_VERSION_1,
.flags = OMAP_I2C_FLAG_APPLY_ERRATA_I207 |
OMAP_I2C_FLAG_RESET_REGS_POSTIDLE |
OMAP_I2C_FLAG_BUS_SHIFT_2,
};
static struct omap_i2c_bus_platform_data omap4_pdata = {
.rev = OMAP_I2C_IP_VERSION_2,
};
static const struct of_device_id omap_i2c_of_match[] = {
{
.compatible = "ti,omap4-i2c",
.data = &omap4_pdata,
},
{
.compatible = "ti,omap3-i2c",
.data = &omap3_pdata,
},
{ },
};
MODULE_DEVICE_TABLE(of, omap_i2c_of_match);
#endif
static int __devinit
omap_i2c_probe(struct platform_device *pdev)
{
struct omap_i2c_dev *dev;
struct i2c_adapter *adap;
struct resource *mem;
const struct omap_i2c_bus_platform_data *pdata =
pdev->dev.platform_data;
struct device_node *node = pdev->dev.of_node;
const struct of_device_id *match;
int irq;
int r;
/* NOTE: driver uses the static register mapping */
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!mem) {
dev_err(&pdev->dev, "no mem resource?\n");
return -ENODEV;
}
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "no irq resource?\n");
return irq;
}
dev = devm_kzalloc(&pdev->dev, sizeof(struct omap_i2c_dev), GFP_KERNEL);
if (!dev) {
dev_err(&pdev->dev, "Menory allocation failed\n");
return -ENOMEM;
}
dev->base = devm_request_and_ioremap(&pdev->dev, mem);
if (!dev->base) {
dev_err(&pdev->dev, "I2C region already claimed\n");
return -ENOMEM;
}
match = of_match_device(of_match_ptr(omap_i2c_of_match), &pdev->dev);
if (match) {
u32 freq = 100000; /* default to 100000 Hz */
pdata = match->data;
dev->dtrev = pdata->rev;
dev->flags = pdata->flags;
of_property_read_u32(node, "clock-frequency", &freq);
/* convert DT freq value in Hz into kHz for speed */
dev->speed = freq / 1000;
} else if (pdata != NULL) {
dev->speed = pdata->clkrate;
dev->flags = pdata->flags;
dev->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat;
dev->dtrev = pdata->rev;
}
dev->dev = &pdev->dev;
dev->irq = irq;
spin_lock_init(&dev->lock);
platform_set_drvdata(pdev, dev);
init_completion(&dev->cmd_complete);
dev->reg_shift = (dev->flags >> OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3;
if (dev->dtrev == OMAP_I2C_IP_VERSION_2)
dev->regs = (u8 *)reg_map_ip_v2;
else
dev->regs = (u8 *)reg_map_ip_v1;
pm_runtime_enable(dev->dev);
pm_runtime_set_autosuspend_delay(dev->dev, OMAP_I2C_PM_TIMEOUT);
pm_runtime_use_autosuspend(dev->dev);
r = pm_runtime_get_sync(dev->dev);
if (IS_ERR_VALUE(r))
goto err_free_mem;
dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
dev->errata = 0;
if (dev->flags & OMAP_I2C_FLAG_APPLY_ERRATA_I207)
dev->errata |= I2C_OMAP_ERRATA_I207;
if (dev->rev <= OMAP_I2C_REV_ON_3430_3530)
dev->errata |= I2C_OMAP_ERRATA_I462;
if (!(dev->flags & OMAP_I2C_FLAG_NO_FIFO)) {
u16 s;
/* Set up the fifo size - Get total size */
s = (omap_i2c_read_reg(dev, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3;
dev->fifo_size = 0x8 << s;
/*
* Set up notification threshold as half the total available
* size. This is to ensure that we can handle the status on int
* call back latencies.
*/
dev->fifo_size = (dev->fifo_size / 2);
if (dev->rev < OMAP_I2C_REV_ON_3630_4430)
dev->b_hw = 1; /* Enable hardware fixes */
/* calculate wakeup latency constraint for MPU */
if (dev->set_mpu_wkup_lat != NULL)
dev->latency = (1000000 * dev->fifo_size) /
(1000 * dev->speed / 8);
}
/* reset ASAP, clearing any IRQs */
omap_i2c_init(dev);
if (dev->rev < OMAP_I2C_OMAP1_REV_2)
r = devm_request_irq(&pdev->dev, dev->irq, omap_i2c_omap1_isr,
IRQF_NO_SUSPEND, pdev->name, dev);
else
r = devm_request_threaded_irq(&pdev->dev, dev->irq,
omap_i2c_isr, omap_i2c_isr_thread,
IRQF_NO_SUSPEND | IRQF_ONESHOT,
pdev->name, dev);
if (r) {
dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
goto err_unuse_clocks;
}
adap = &dev->adapter;
i2c_set_adapdata(adap, dev);
adap->owner = THIS_MODULE;
adap->class = I2C_CLASS_HWMON;
strlcpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
adap->algo = &omap_i2c_algo;
adap->dev.parent = &pdev->dev;
adap->dev.of_node = pdev->dev.of_node;
/* i2c device drivers may be active on return from add_adapter() */
adap->nr = pdev->id;
r = i2c_add_numbered_adapter(adap);
if (r) {
dev_err(dev->dev, "failure adding adapter\n");
goto err_unuse_clocks;
}
dev_info(dev->dev, "bus %d rev%d.%d.%d at %d kHz\n", adap->nr,
dev->dtrev, dev->rev >> 4, dev->rev & 0xf, dev->speed);
of_i2c_register_devices(adap);
pm_runtime_mark_last_busy(dev->dev);
pm_runtime_put_autosuspend(dev->dev);
return 0;
err_unuse_clocks:
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
pm_runtime_put(dev->dev);
pm_runtime_disable(&pdev->dev);
err_free_mem:
platform_set_drvdata(pdev, NULL);
return r;
}
static int __devexit omap_i2c_remove(struct platform_device *pdev)
{
struct omap_i2c_dev *dev = platform_get_drvdata(pdev);
int ret;
platform_set_drvdata(pdev, NULL);
i2c_del_adapter(&dev->adapter);
ret = pm_runtime_get_sync(&pdev->dev);
if (IS_ERR_VALUE(ret))
return ret;
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
pm_runtime_put(&pdev->dev);
pm_runtime_disable(&pdev->dev);
return 0;
}
#ifdef CONFIG_PM
#ifdef CONFIG_PM_RUNTIME
static int omap_i2c_runtime_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
u16 iv;
_dev->iestate = omap_i2c_read_reg(_dev, OMAP_I2C_IE_REG);
omap_i2c_write_reg(_dev, OMAP_I2C_IE_REG, 0);
if (_dev->rev < OMAP_I2C_OMAP1_REV_2) {
iv = omap_i2c_read_reg(_dev, OMAP_I2C_IV_REG); /* Read clears */
} else {
omap_i2c_write_reg(_dev, OMAP_I2C_STAT_REG, _dev->iestate);
/* Flush posted write */
omap_i2c_read_reg(_dev, OMAP_I2C_STAT_REG);
}
return 0;
}
static int omap_i2c_runtime_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
if (_dev->flags & OMAP_I2C_FLAG_RESET_REGS_POSTIDLE) {
omap_i2c_write_reg(_dev, OMAP_I2C_CON_REG, 0);
omap_i2c_write_reg(_dev, OMAP_I2C_PSC_REG, _dev->pscstate);
omap_i2c_write_reg(_dev, OMAP_I2C_SCLL_REG, _dev->scllstate);
omap_i2c_write_reg(_dev, OMAP_I2C_SCLH_REG, _dev->sclhstate);
omap_i2c_write_reg(_dev, OMAP_I2C_BUF_REG, _dev->bufstate);
omap_i2c_write_reg(_dev, OMAP_I2C_SYSC_REG, _dev->syscstate);
omap_i2c_write_reg(_dev, OMAP_I2C_WE_REG, _dev->westate);
omap_i2c_write_reg(_dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
}
/*
* Don't write to this register if the IE state is 0 as it can
* cause deadlock.
*/
if (_dev->iestate)
omap_i2c_write_reg(_dev, OMAP_I2C_IE_REG, _dev->iestate);
return 0;
}
#endif /* CONFIG_PM_RUNTIME */
static struct dev_pm_ops omap_i2c_pm_ops = {
SET_RUNTIME_PM_OPS(omap_i2c_runtime_suspend,
omap_i2c_runtime_resume, NULL)
};
#define OMAP_I2C_PM_OPS (&omap_i2c_pm_ops)
#else
#define OMAP_I2C_PM_OPS NULL
#endif /* CONFIG_PM */
static struct platform_driver omap_i2c_driver = {
.probe = omap_i2c_probe,
.remove = __devexit_p(omap_i2c_remove),
.driver = {
.name = "omap_i2c",
.owner = THIS_MODULE,
.pm = OMAP_I2C_PM_OPS,
.of_match_table = of_match_ptr(omap_i2c_of_match),
},
};
/* I2C may be needed to bring up other drivers */
static int __init
omap_i2c_init_driver(void)
{
return platform_driver_register(&omap_i2c_driver);
}
subsys_initcall(omap_i2c_init_driver);
static void __exit omap_i2c_exit_driver(void)
{
platform_driver_unregister(&omap_i2c_driver);
}
module_exit(omap_i2c_exit_driver);
MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:omap_i2c");
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