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kernel_optimize_test/drivers/i2c/busses/i2c-omap.c
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00

677 lines
18 KiB
C
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/*
* TI OMAP I2C master mode driver
*
* Copyright (C) 2003 MontaVista Software, Inc.
* Copyright (C) 2004 Texas Instruments.
*
* Updated to work with multiple I2C interfaces on 24xx by
* Tony Lindgren <tony@atomide.com> and Imre Deak <imre.deak@nokia.com>
* Copyright (C) 2005 Nokia Corporation
*
* Cleaned up by Juha Yrjölä <juha.yrjola@nokia.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 <asm/io.h>
/* timeout waiting for the controller to respond */
#define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
#define OMAP_I2C_REV_REG 0x00
#define OMAP_I2C_IE_REG 0x04
#define OMAP_I2C_STAT_REG 0x08
#define OMAP_I2C_IV_REG 0x0c
#define OMAP_I2C_SYSS_REG 0x10
#define OMAP_I2C_BUF_REG 0x14
#define OMAP_I2C_CNT_REG 0x18
#define OMAP_I2C_DATA_REG 0x1c
#define OMAP_I2C_SYSC_REG 0x20
#define OMAP_I2C_CON_REG 0x24
#define OMAP_I2C_OA_REG 0x28
#define OMAP_I2C_SA_REG 0x2c
#define OMAP_I2C_PSC_REG 0x30
#define OMAP_I2C_SCLL_REG 0x34
#define OMAP_I2C_SCLH_REG 0x38
#define OMAP_I2C_SYSTEST_REG 0x3c
/* I2C Interrupt Enable Register (OMAP_I2C_IE): */
#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_SBD (1 << 15) /* Single byte data */
#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 Buffer Configuration Register (OMAP_I2C_BUF): */
#define OMAP_I2C_BUF_RDMA_EN (1 << 15) /* RX DMA channel enable */
#define OMAP_I2C_BUF_XDMA_EN (1 << 7) /* TX DMA channel enable */
/* 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_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 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
/* I2C System Status register (OMAP_I2C_SYSS): */
#define OMAP_I2C_SYSS_RDONE (1 << 0) /* Reset Done */
/* I2C System Configuration Register (OMAP_I2C_SYSC): */
#define OMAP_I2C_SYSC_SRST (1 << 1) /* Soft Reset */
/* REVISIT: Use platform_data instead of module parameters */
/* Fast Mode = 400 kHz, Standard = 100 kHz */
static int clock = 100; /* Default: 100 kHz */
module_param(clock, int, 0);
MODULE_PARM_DESC(clock, "Set I2C clock in kHz: 400=fast mode (default == 100)");
struct omap_i2c_dev {
struct device *dev;
void __iomem *base; /* virtual */
int irq;
struct clk *iclk; /* Interface clock */
struct clk *fclk; /* Functional clock */
struct completion cmd_complete;
struct resource *ioarea;
u16 cmd_err;
u8 *buf;
size_t buf_len;
struct i2c_adapter adapter;
unsigned rev1:1;
};
static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
int reg, u16 val)
{
__raw_writew(val, i2c_dev->base + reg);
}
static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
{
return __raw_readw(i2c_dev->base + reg);
}
static int omap_i2c_get_clocks(struct omap_i2c_dev *dev)
{
if (cpu_is_omap16xx() || cpu_is_omap24xx()) {
dev->iclk = clk_get(dev->dev, "i2c_ick");
if (IS_ERR(dev->iclk)) {
dev->iclk = NULL;
return -ENODEV;
}
}
dev->fclk = clk_get(dev->dev, "i2c_fck");
if (IS_ERR(dev->fclk)) {
if (dev->iclk != NULL) {
clk_put(dev->iclk);
dev->iclk = NULL;
}
dev->fclk = NULL;
return -ENODEV;
}
return 0;
}
static void omap_i2c_put_clocks(struct omap_i2c_dev *dev)
{
clk_put(dev->fclk);
dev->fclk = NULL;
if (dev->iclk != NULL) {
clk_put(dev->iclk);
dev->iclk = NULL;
}
}
static void omap_i2c_enable_clocks(struct omap_i2c_dev *dev)
{
if (dev->iclk != NULL)
clk_enable(dev->iclk);
clk_enable(dev->fclk);
}
static void omap_i2c_disable_clocks(struct omap_i2c_dev *dev)
{
if (dev->iclk != NULL)
clk_disable(dev->iclk);
clk_disable(dev->fclk);
}
static int omap_i2c_init(struct omap_i2c_dev *dev)
{
u16 psc = 0;
unsigned long fclk_rate = 12000000;
unsigned long timeout;
if (!dev->rev1) {
omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, OMAP_I2C_SYSC_SRST);
/* 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) &
OMAP_I2C_SYSS_RDONE)) {
if (time_after(jiffies, timeout)) {
dev_warn(dev->dev, "timeout waiting"
"for controller reset\n");
return -ETIMEDOUT;
}
msleep(1);
}
}
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
if (cpu_class_is_omap1()) {
struct clk *armxor_ck;
armxor_ck = clk_get(NULL, "armxor_ck");
if (IS_ERR(armxor_ck))
dev_warn(dev->dev, "Could not get armxor_ck\n");
else {
fclk_rate = clk_get_rate(armxor_ck);
clk_put(armxor_ck);
}
/* 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 > 16000000)
psc = (fclk_rate + 8000000) / 12000000;
}
/* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc);
/* Program desired operating rate */
fclk_rate /= (psc + 1) * 1000;
if (psc > 2)
psc = 2;
omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG,
fclk_rate / (clock * 2) - 7 + psc);
omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG,
fclk_rate / (clock * 2) - 7 + psc);
/* Take the I2C module out of reset: */
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
/* Enable interrupts */
omap_i2c_write_reg(dev, OMAP_I2C_IE_REG,
(OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
OMAP_I2C_IE_AL));
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;
}
/*
* 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);
int r;
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;
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;
omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len);
init_completion(&dev->cmd_complete);
dev->cmd_err = 0;
w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
if (msg->flags & I2C_M_TEN)
w |= OMAP_I2C_CON_XA;
if (!(msg->flags & I2C_M_RD))
w |= OMAP_I2C_CON_TRX;
if (stop)
w |= OMAP_I2C_CON_STP;
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
r = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
OMAP_I2C_TIMEOUT);
dev->buf_len = 0;
if (r < 0)
return r;
if (r == 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;
omap_i2c_enable_clocks(dev);
/* REVISIT: initialize and use adap->retries. This is an optional
* feature */
if ((r = omap_i2c_wait_for_bb(dev)) < 0)
goto out;
for (i = 0; i < num; i++) {
r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
if (r != 0)
break;
}
if (r == 0)
r = num;
out:
omap_i2c_disable_clocks(dev);
return r;
}
static u32
omap_i2c_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
}
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 irqreturn_t
omap_i2c_rev1_isr(int this_irq, void *dev_id)
{
struct omap_i2c_dev *dev = dev_id;
u16 iv, w;
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;
}
static irqreturn_t
omap_i2c_isr(int this_irq, void *dev_id)
{
struct omap_i2c_dev *dev = dev_id;
u16 bits;
u16 stat, w;
int count = 0;
bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) {
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;
}
omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
if (stat & OMAP_I2C_STAT_ARDY) {
omap_i2c_complete_cmd(dev, 0);
continue;
}
if (stat & OMAP_I2C_STAT_RRDY) {
w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
if (dev->buf_len) {
*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");
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RRDY);
continue;
}
if (stat & OMAP_I2C_STAT_XRDY) {
w = 0;
if (dev->buf_len) {
w = *dev->buf++;
dev->buf_len--;
if (dev->buf_len) {
w |= *dev->buf++ << 8;
dev->buf_len--;
}
} else
dev_err(dev->dev, "XRDY IRQ while no"
"data to send\n");
omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY);
continue;
}
if (stat & OMAP_I2C_STAT_ROVR) {
dev_err(dev->dev, "Receive overrun\n");
dev->cmd_err |= OMAP_I2C_STAT_ROVR;
}
if (stat & OMAP_I2C_STAT_XUDF) {
dev_err(dev->dev, "Transmit overflow\n");
dev->cmd_err |= OMAP_I2C_STAT_XUDF;
}
if (stat & OMAP_I2C_STAT_NACK) {
omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
OMAP_I2C_CON_STP);
}
if (stat & OMAP_I2C_STAT_AL) {
dev_err(dev->dev, "Arbitration lost\n");
omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
}
}
return count ? IRQ_HANDLED : IRQ_NONE;
}
static const struct i2c_algorithm omap_i2c_algo = {
.master_xfer = omap_i2c_xfer,
.functionality = omap_i2c_func,
};
static int
omap_i2c_probe(struct platform_device *pdev)
{
struct omap_i2c_dev *dev;
struct i2c_adapter *adap;
struct resource *mem, *irq, *ioarea;
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_resource(pdev, IORESOURCE_IRQ, 0);
if (!irq) {
dev_err(&pdev->dev, "no irq resource?\n");
return -ENODEV;
}
ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
pdev->name);
if (!ioarea) {
dev_err(&pdev->dev, "I2C region already claimed\n");
return -EBUSY;
}
if (clock > 200)
clock = 400; /* Fast mode */
else
clock = 100; /* Standard mode */
dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL);
if (!dev) {
r = -ENOMEM;
goto err_release_region;
}
dev->dev = &pdev->dev;
dev->irq = irq->start;
dev->base = (void __iomem *) IO_ADDRESS(mem->start);
platform_set_drvdata(pdev, dev);
if ((r = omap_i2c_get_clocks(dev)) != 0)
goto err_free_mem;
omap_i2c_enable_clocks(dev);
if (cpu_is_omap15xx())
dev->rev1 = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) < 0x20;
/* reset ASAP, clearing any IRQs */
omap_i2c_init(dev);
r = request_irq(dev->irq, dev->rev1 ? omap_i2c_rev1_isr : omap_i2c_isr,
0, pdev->name, dev);
if (r) {
dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
goto err_unuse_clocks;
}
r = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n",
pdev->id, r >> 4, r & 0xf, clock);
adap = &dev->adapter;
i2c_set_adapdata(adap, dev);
adap->owner = THIS_MODULE;
adap->class = I2C_CLASS_HWMON;
strncpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
adap->algo = &omap_i2c_algo;
adap->dev.parent = &pdev->dev;
/* i2c device drivers may be active on return from add_adapter() */
r = i2c_add_adapter(adap);
if (r) {
dev_err(dev->dev, "failure adding adapter\n");
goto err_free_irq;
}
omap_i2c_disable_clocks(dev);
return 0;
err_free_irq:
free_irq(dev->irq, dev);
err_unuse_clocks:
omap_i2c_disable_clocks(dev);
omap_i2c_put_clocks(dev);
err_free_mem:
platform_set_drvdata(pdev, NULL);
kfree(dev);
err_release_region:
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
release_mem_region(mem->start, (mem->end - mem->start) + 1);
return r;
}
static int
omap_i2c_remove(struct platform_device *pdev)
{
struct omap_i2c_dev *dev = platform_get_drvdata(pdev);
struct resource *mem;
platform_set_drvdata(pdev, NULL);
free_irq(dev->irq, dev);
i2c_del_adapter(&dev->adapter);
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
omap_i2c_put_clocks(dev);
kfree(dev);
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(mem->start, (mem->end - mem->start) + 1);
return 0;
}
static struct platform_driver omap_i2c_driver = {
.probe = omap_i2c_probe,
.remove = omap_i2c_remove,
.driver = {
.name = "i2c_omap",
.owner = THIS_MODULE,
},
};
/* 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");
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