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android_kernel_xiaomi_sm8350/drivers/i2c/busses/i2c-s3c2410.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

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/* linux/drivers/i2c/busses/i2c-s3c2410.c
*
* Copyright (C) 2004,2005 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*
* S3C2410 I2C Controller
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/i2c-id.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <asm/hardware.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/arch/regs-gpio.h>
#include <asm/arch/regs-iic.h>
#include <asm/arch/iic.h>
/* i2c controller state */
enum s3c24xx_i2c_state {
STATE_IDLE,
STATE_START,
STATE_READ,
STATE_WRITE,
STATE_STOP
};
struct s3c24xx_i2c {
spinlock_t lock;
wait_queue_head_t wait;
struct i2c_msg *msg;
unsigned int msg_num;
unsigned int msg_idx;
unsigned int msg_ptr;
enum s3c24xx_i2c_state state;
void __iomem *regs;
struct clk *clk;
struct device *dev;
struct resource *irq;
struct resource *ioarea;
struct i2c_adapter adap;
};
/* default platform data to use if not supplied in the platform_device
*/
static struct s3c2410_platform_i2c s3c24xx_i2c_default_platform = {
.flags = 0,
.slave_addr = 0x10,
.bus_freq = 100*1000,
.max_freq = 400*1000,
.sda_delay = S3C2410_IICLC_SDA_DELAY5 | S3C2410_IICLC_FILTER_ON,
};
/* s3c24xx_i2c_is2440()
*
* return true is this is an s3c2440
*/
static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c)
{
struct platform_device *pdev = to_platform_device(i2c->dev);
return !strcmp(pdev->name, "s3c2440-i2c");
}
/* s3c24xx_i2c_get_platformdata
*
* get the platform data associated with the given device, or return
* the default if there is none
*/
static inline struct s3c2410_platform_i2c *s3c24xx_i2c_get_platformdata(struct device *dev)
{
if (dev->platform_data != NULL)
return (struct s3c2410_platform_i2c *)dev->platform_data;
return &s3c24xx_i2c_default_platform;
}
/* s3c24xx_i2c_master_complete
*
* complete the message and wake up the caller, using the given return code,
* or zero to mean ok.
*/
static inline void s3c24xx_i2c_master_complete(struct s3c24xx_i2c *i2c, int ret)
{
dev_dbg(i2c->dev, "master_complete %d\n", ret);
i2c->msg_ptr = 0;
i2c->msg = NULL;
i2c->msg_idx ++;
i2c->msg_num = 0;
if (ret)
i2c->msg_idx = ret;
wake_up(&i2c->wait);
}
static inline void s3c24xx_i2c_disable_ack(struct s3c24xx_i2c *i2c)
{
unsigned long tmp;
tmp = readl(i2c->regs + S3C2410_IICCON);
writel(tmp & ~S3C2410_IICCON_ACKEN, i2c->regs + S3C2410_IICCON);
}
static inline void s3c24xx_i2c_enable_ack(struct s3c24xx_i2c *i2c)
{
unsigned long tmp;
tmp = readl(i2c->regs + S3C2410_IICCON);
writel(tmp | S3C2410_IICCON_ACKEN, i2c->regs + S3C2410_IICCON);
}
/* irq enable/disable functions */
static inline void s3c24xx_i2c_disable_irq(struct s3c24xx_i2c *i2c)
{
unsigned long tmp;
tmp = readl(i2c->regs + S3C2410_IICCON);
writel(tmp & ~S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON);
}
static inline void s3c24xx_i2c_enable_irq(struct s3c24xx_i2c *i2c)
{
unsigned long tmp;
tmp = readl(i2c->regs + S3C2410_IICCON);
writel(tmp | S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON);
}
/* s3c24xx_i2c_message_start
*
* put the start of a message onto the bus
*/
static void s3c24xx_i2c_message_start(struct s3c24xx_i2c *i2c,
struct i2c_msg *msg)
{
unsigned int addr = (msg->addr & 0x7f) << 1;
unsigned long stat;
unsigned long iiccon;
stat = 0;
stat |= S3C2410_IICSTAT_TXRXEN;
if (msg->flags & I2C_M_RD) {
stat |= S3C2410_IICSTAT_MASTER_RX;
addr |= 1;
} else
stat |= S3C2410_IICSTAT_MASTER_TX;
if (msg->flags & I2C_M_REV_DIR_ADDR)
addr ^= 1;
// todo - check for wether ack wanted or not
s3c24xx_i2c_enable_ack(i2c);
iiccon = readl(i2c->regs + S3C2410_IICCON);
writel(stat, i2c->regs + S3C2410_IICSTAT);
dev_dbg(i2c->dev, "START: %08lx to IICSTAT, %02x to DS\n", stat, addr);
writeb(addr, i2c->regs + S3C2410_IICDS);
// delay a bit and reset iiccon before setting start (per samsung)
udelay(1);
dev_dbg(i2c->dev, "iiccon, %08lx\n", iiccon);
writel(iiccon, i2c->regs + S3C2410_IICCON);
stat |= S3C2410_IICSTAT_START;
writel(stat, i2c->regs + S3C2410_IICSTAT);
}
static inline void s3c24xx_i2c_stop(struct s3c24xx_i2c *i2c, int ret)
{
unsigned long iicstat = readl(i2c->regs + S3C2410_IICSTAT);
dev_dbg(i2c->dev, "STOP\n");
/* stop the transfer */
iicstat &= ~ S3C2410_IICSTAT_START;
writel(iicstat, i2c->regs + S3C2410_IICSTAT);
i2c->state = STATE_STOP;
s3c24xx_i2c_master_complete(i2c, ret);
s3c24xx_i2c_disable_irq(i2c);
}
/* helper functions to determine the current state in the set of
* messages we are sending */
/* is_lastmsg()
*
* returns TRUE if the current message is the last in the set
*/
static inline int is_lastmsg(struct s3c24xx_i2c *i2c)
{
return i2c->msg_idx >= (i2c->msg_num - 1);
}
/* is_msglast
*
* returns TRUE if we this is the last byte in the current message
*/
static inline int is_msglast(struct s3c24xx_i2c *i2c)
{
return i2c->msg_ptr == i2c->msg->len-1;
}
/* is_msgend
*
* returns TRUE if we reached the end of the current message
*/
static inline int is_msgend(struct s3c24xx_i2c *i2c)
{
return i2c->msg_ptr >= i2c->msg->len;
}
/* i2s_s3c_irq_nextbyte
*
* process an interrupt and work out what to do
*/
static int i2s_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat)
{
unsigned long tmp;
unsigned char byte;
int ret = 0;
switch (i2c->state) {
case STATE_IDLE:
dev_err(i2c->dev, "%s: called in STATE_IDLE\n", __FUNCTION__);
goto out;
break;
case STATE_STOP:
dev_err(i2c->dev, "%s: called in STATE_STOP\n", __FUNCTION__);
s3c24xx_i2c_disable_irq(i2c);
goto out_ack;
case STATE_START:
/* last thing we did was send a start condition on the
* bus, or started a new i2c message
*/
if (iicstat & S3C2410_IICSTAT_LASTBIT &&
!(i2c->msg->flags & I2C_M_IGNORE_NAK)) {
/* ack was not received... */
dev_dbg(i2c->dev, "ack was not received\n");
s3c24xx_i2c_stop(i2c, -EREMOTEIO);
goto out_ack;
}
if (i2c->msg->flags & I2C_M_RD)
i2c->state = STATE_READ;
else
i2c->state = STATE_WRITE;
/* terminate the transfer if there is nothing to do
* (used by the i2c probe to find devices */
if (is_lastmsg(i2c) && i2c->msg->len == 0) {
s3c24xx_i2c_stop(i2c, 0);
goto out_ack;
}
if (i2c->state == STATE_READ)
goto prepare_read;
/* fall through to the write state, as we will need to
* send a byte as well */
case STATE_WRITE:
/* we are writing data to the device... check for the
* end of the message, and if so, work out what to do
*/
retry_write:
if (!is_msgend(i2c)) {
byte = i2c->msg->buf[i2c->msg_ptr++];
writeb(byte, i2c->regs + S3C2410_IICDS);
} else if (!is_lastmsg(i2c)) {
/* we need to go to the next i2c message */
dev_dbg(i2c->dev, "WRITE: Next Message\n");
i2c->msg_ptr = 0;
i2c->msg_idx ++;
i2c->msg++;
/* check to see if we need to do another message */
if (i2c->msg->flags & I2C_M_NOSTART) {
if (i2c->msg->flags & I2C_M_RD) {
/* cannot do this, the controller
* forces us to send a new START
* when we change direction */
s3c24xx_i2c_stop(i2c, -EINVAL);
}
goto retry_write;
} else {
/* send the new start */
s3c24xx_i2c_message_start(i2c, i2c->msg);
i2c->state = STATE_START;
}
} else {
/* send stop */
s3c24xx_i2c_stop(i2c, 0);
}
break;
case STATE_READ:
/* we have a byte of data in the data register, do
* something with it, and then work out wether we are
* going to do any more read/write
*/
if (!(i2c->msg->flags & I2C_M_IGNORE_NAK) &&
!(is_msglast(i2c) && is_lastmsg(i2c))) {
if (iicstat & S3C2410_IICSTAT_LASTBIT) {
dev_dbg(i2c->dev, "READ: No Ack\n");
s3c24xx_i2c_stop(i2c, -ECONNREFUSED);
goto out_ack;
}
}
byte = readb(i2c->regs + S3C2410_IICDS);
i2c->msg->buf[i2c->msg_ptr++] = byte;
prepare_read:
if (is_msglast(i2c)) {
/* last byte of buffer */
if (is_lastmsg(i2c))
s3c24xx_i2c_disable_ack(i2c);
} else if (is_msgend(i2c)) {
/* ok, we've read the entire buffer, see if there
* is anything else we need to do */
if (is_lastmsg(i2c)) {
/* last message, send stop and complete */
dev_dbg(i2c->dev, "READ: Send Stop\n");
s3c24xx_i2c_stop(i2c, 0);
} else {
/* go to the next transfer */
dev_dbg(i2c->dev, "READ: Next Transfer\n");
i2c->msg_ptr = 0;
i2c->msg_idx++;
i2c->msg++;
}
}
break;
}
/* acknowlegde the IRQ and get back on with the work */
out_ack:
tmp = readl(i2c->regs + S3C2410_IICCON);
tmp &= ~S3C2410_IICCON_IRQPEND;
writel(tmp, i2c->regs + S3C2410_IICCON);
out:
return ret;
}
/* s3c24xx_i2c_irq
*
* top level IRQ servicing routine
*/
static irqreturn_t s3c24xx_i2c_irq(int irqno, void *dev_id)
{
struct s3c24xx_i2c *i2c = dev_id;
unsigned long status;
unsigned long tmp;
status = readl(i2c->regs + S3C2410_IICSTAT);
if (status & S3C2410_IICSTAT_ARBITR) {
// deal with arbitration loss
dev_err(i2c->dev, "deal with arbitration loss\n");
}
if (i2c->state == STATE_IDLE) {
dev_dbg(i2c->dev, "IRQ: error i2c->state == IDLE\n");
tmp = readl(i2c->regs + S3C2410_IICCON);
tmp &= ~S3C2410_IICCON_IRQPEND;
writel(tmp, i2c->regs + S3C2410_IICCON);
goto out;
}
/* pretty much this leaves us with the fact that we've
* transmitted or received whatever byte we last sent */
i2s_s3c_irq_nextbyte(i2c, status);
out:
return IRQ_HANDLED;
}
/* s3c24xx_i2c_set_master
*
* get the i2c bus for a master transaction
*/
static int s3c24xx_i2c_set_master(struct s3c24xx_i2c *i2c)
{
unsigned long iicstat;
int timeout = 400;
while (timeout-- > 0) {
iicstat = readl(i2c->regs + S3C2410_IICSTAT);
if (!(iicstat & S3C2410_IICSTAT_BUSBUSY))
return 0;
msleep(1);
}
dev_dbg(i2c->dev, "timeout: GPEDAT is %08x\n",
__raw_readl(S3C2410_GPEDAT));
return -ETIMEDOUT;
}
/* s3c24xx_i2c_doxfer
*
* this starts an i2c transfer
*/
static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c, struct i2c_msg *msgs, int num)
{
unsigned long timeout;
int ret;
ret = s3c24xx_i2c_set_master(i2c);
if (ret != 0) {
dev_err(i2c->dev, "cannot get bus (error %d)\n", ret);
ret = -EAGAIN;
goto out;
}
spin_lock_irq(&i2c->lock);
i2c->msg = msgs;
i2c->msg_num = num;
i2c->msg_ptr = 0;
i2c->msg_idx = 0;
i2c->state = STATE_START;
s3c24xx_i2c_enable_irq(i2c);
s3c24xx_i2c_message_start(i2c, msgs);
spin_unlock_irq(&i2c->lock);
timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
ret = i2c->msg_idx;
/* having these next two as dev_err() makes life very
* noisy when doing an i2cdetect */
if (timeout == 0)
dev_dbg(i2c->dev, "timeout\n");
else if (ret != num)
dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret);
/* ensure the stop has been through the bus */
msleep(1);
out:
return ret;
}
/* s3c24xx_i2c_xfer
*
* first port of call from the i2c bus code when an message needs
* transferring across the i2c bus.
*/
static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
struct i2c_msg *msgs, int num)
{
struct s3c24xx_i2c *i2c = (struct s3c24xx_i2c *)adap->algo_data;
int retry;
int ret;
for (retry = 0; retry < adap->retries; retry++) {
ret = s3c24xx_i2c_doxfer(i2c, msgs, num);
if (ret != -EAGAIN)
return ret;
dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry);
udelay(100);
}
return -EREMOTEIO;
}
/* declare our i2c functionality */
static u32 s3c24xx_i2c_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
}
/* i2c bus registration info */
static const struct i2c_algorithm s3c24xx_i2c_algorithm = {
.master_xfer = s3c24xx_i2c_xfer,
.functionality = s3c24xx_i2c_func,
};
static struct s3c24xx_i2c s3c24xx_i2c = {
.lock = SPIN_LOCK_UNLOCKED,
.wait = __WAIT_QUEUE_HEAD_INITIALIZER(s3c24xx_i2c.wait),
.adap = {
.name = "s3c2410-i2c",
.owner = THIS_MODULE,
.algo = &s3c24xx_i2c_algorithm,
.retries = 2,
.class = I2C_CLASS_HWMON,
},
};
/* s3c24xx_i2c_calcdivisor
*
* return the divisor settings for a given frequency
*/
static int s3c24xx_i2c_calcdivisor(unsigned long clkin, unsigned int wanted,
unsigned int *div1, unsigned int *divs)
{
unsigned int calc_divs = clkin / wanted;
unsigned int calc_div1;
if (calc_divs > (16*16))
calc_div1 = 512;
else
calc_div1 = 16;
calc_divs += calc_div1-1;
calc_divs /= calc_div1;
if (calc_divs == 0)
calc_divs = 1;
if (calc_divs > 17)
calc_divs = 17;
*divs = calc_divs;
*div1 = calc_div1;
return clkin / (calc_divs * calc_div1);
}
/* freq_acceptable
*
* test wether a frequency is within the acceptable range of error
*/
static inline int freq_acceptable(unsigned int freq, unsigned int wanted)
{
int diff = freq - wanted;
return (diff >= -2 && diff <= 2);
}
/* s3c24xx_i2c_getdivisor
*
* work out a divisor for the user requested frequency setting,
* either by the requested frequency, or scanning the acceptable
* range of frequencies until something is found
*/
static int s3c24xx_i2c_getdivisor(struct s3c24xx_i2c *i2c,
struct s3c2410_platform_i2c *pdata,
unsigned long *iicon,
unsigned int *got)
{
unsigned long clkin = clk_get_rate(i2c->clk);
unsigned int divs, div1;
int freq;
int start, end;
clkin /= 1000; /* clkin now in KHz */
dev_dbg(i2c->dev, "pdata %p, freq %lu %lu..%lu\n",
pdata, pdata->bus_freq, pdata->min_freq, pdata->max_freq);
if (pdata->bus_freq != 0) {
freq = s3c24xx_i2c_calcdivisor(clkin, pdata->bus_freq/1000,
&div1, &divs);
if (freq_acceptable(freq, pdata->bus_freq/1000))
goto found;
}
/* ok, we may have to search for something suitable... */
start = (pdata->max_freq == 0) ? pdata->bus_freq : pdata->max_freq;
end = pdata->min_freq;
start /= 1000;
end /= 1000;
/* search loop... */
for (; start > end; start--) {
freq = s3c24xx_i2c_calcdivisor(clkin, start, &div1, &divs);
if (freq_acceptable(freq, start))
goto found;
}
/* cannot find frequency spec */
return -EINVAL;
found:
*got = freq;
*iicon |= (divs-1);
*iicon |= (div1 == 512) ? S3C2410_IICCON_TXDIV_512 : 0;
return 0;
}
/* s3c24xx_i2c_init
*
* initialise the controller, set the IO lines and frequency
*/
static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
{
unsigned long iicon = S3C2410_IICCON_IRQEN | S3C2410_IICCON_ACKEN;
struct s3c2410_platform_i2c *pdata;
unsigned int freq;
/* get the plafrom data */
pdata = s3c24xx_i2c_get_platformdata(i2c->adap.dev.parent);
/* inititalise the gpio */
s3c2410_gpio_cfgpin(S3C2410_GPE15, S3C2410_GPE15_IICSDA);
s3c2410_gpio_cfgpin(S3C2410_GPE14, S3C2410_GPE14_IICSCL);
/* write slave address */
writeb(pdata->slave_addr, i2c->regs + S3C2410_IICADD);
dev_info(i2c->dev, "slave address 0x%02x\n", pdata->slave_addr);
/* we need to work out the divisors for the clock... */
if (s3c24xx_i2c_getdivisor(i2c, pdata, &iicon, &freq) != 0) {
dev_err(i2c->dev, "cannot meet bus frequency required\n");
return -EINVAL;
}
/* todo - check that the i2c lines aren't being dragged anywhere */
dev_info(i2c->dev, "bus frequency set to %d KHz\n", freq);
dev_dbg(i2c->dev, "S3C2410_IICCON=0x%02lx\n", iicon);
writel(iicon, i2c->regs + S3C2410_IICCON);
/* check for s3c2440 i2c controller */
if (s3c24xx_i2c_is2440(i2c)) {
dev_dbg(i2c->dev, "S3C2440_IICLC=%08x\n", pdata->sda_delay);
writel(pdata->sda_delay, i2c->regs + S3C2440_IICLC);
}
return 0;
}
static void s3c24xx_i2c_free(struct s3c24xx_i2c *i2c)
{
if (i2c->clk != NULL && !IS_ERR(i2c->clk)) {
clk_disable(i2c->clk);
clk_put(i2c->clk);
i2c->clk = NULL;
}
if (i2c->regs != NULL) {
iounmap(i2c->regs);
i2c->regs = NULL;
}
if (i2c->ioarea != NULL) {
release_resource(i2c->ioarea);
kfree(i2c->ioarea);
i2c->ioarea = NULL;
}
}
/* s3c24xx_i2c_probe
*
* called by the bus driver when a suitable device is found
*/
static int s3c24xx_i2c_probe(struct platform_device *pdev)
{
struct s3c24xx_i2c *i2c = &s3c24xx_i2c;
struct resource *res;
int ret;
/* find the clock and enable it */
i2c->dev = &pdev->dev;
i2c->clk = clk_get(&pdev->dev, "i2c");
if (IS_ERR(i2c->clk)) {
dev_err(&pdev->dev, "cannot get clock\n");
ret = -ENOENT;
goto out;
}
dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk);
clk_enable(i2c->clk);
/* map the registers */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (res == NULL) {
dev_err(&pdev->dev, "cannot find IO resource\n");
ret = -ENOENT;
goto out;
}
i2c->ioarea = request_mem_region(res->start, (res->end-res->start)+1,
pdev->name);
if (i2c->ioarea == NULL) {
dev_err(&pdev->dev, "cannot request IO\n");
ret = -ENXIO;
goto out;
}
i2c->regs = ioremap(res->start, (res->end-res->start)+1);
if (i2c->regs == NULL) {
dev_err(&pdev->dev, "cannot map IO\n");
ret = -ENXIO;
goto out;
}
dev_dbg(&pdev->dev, "registers %p (%p, %p)\n", i2c->regs, i2c->ioarea, res);
/* setup info block for the i2c core */
i2c->adap.algo_data = i2c;
i2c->adap.dev.parent = &pdev->dev;
/* initialise the i2c controller */
ret = s3c24xx_i2c_init(i2c);
if (ret != 0)
goto out;
/* find the IRQ for this unit (note, this relies on the init call to
* ensure no current IRQs pending
*/
res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (res == NULL) {
dev_err(&pdev->dev, "cannot find IRQ\n");
ret = -ENOENT;
goto out;
}
ret = request_irq(res->start, s3c24xx_i2c_irq, IRQF_DISABLED,
pdev->name, i2c);
if (ret != 0) {
dev_err(&pdev->dev, "cannot claim IRQ\n");
goto out;
}
i2c->irq = res;
dev_dbg(&pdev->dev, "irq resource %p (%ld)\n", res, res->start);
ret = i2c_add_adapter(&i2c->adap);
if (ret < 0) {
dev_err(&pdev->dev, "failed to add bus to i2c core\n");
goto out;
}
platform_set_drvdata(pdev, i2c);
dev_info(&pdev->dev, "%s: S3C I2C adapter\n", i2c->adap.dev.bus_id);
out:
if (ret < 0)
s3c24xx_i2c_free(i2c);
return ret;
}
/* s3c24xx_i2c_remove
*
* called when device is removed from the bus
*/
static int s3c24xx_i2c_remove(struct platform_device *pdev)
{
struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
if (i2c != NULL) {
s3c24xx_i2c_free(i2c);
platform_set_drvdata(pdev, NULL);
}
return 0;
}
#ifdef CONFIG_PM
static int s3c24xx_i2c_resume(struct platform_device *dev)
{
struct s3c24xx_i2c *i2c = platform_get_drvdata(dev);
if (i2c != NULL)
s3c24xx_i2c_init(i2c);
return 0;
}
#else
#define s3c24xx_i2c_resume NULL
#endif
/* device driver for platform bus bits */
static struct platform_driver s3c2410_i2c_driver = {
.probe = s3c24xx_i2c_probe,
.remove = s3c24xx_i2c_remove,
.resume = s3c24xx_i2c_resume,
.driver = {
.owner = THIS_MODULE,
.name = "s3c2410-i2c",
},
};
static struct platform_driver s3c2440_i2c_driver = {
.probe = s3c24xx_i2c_probe,
.remove = s3c24xx_i2c_remove,
.resume = s3c24xx_i2c_resume,
.driver = {
.owner = THIS_MODULE,
.name = "s3c2440-i2c",
},
};
static int __init i2c_adap_s3c_init(void)
{
int ret;
ret = platform_driver_register(&s3c2410_i2c_driver);
if (ret == 0) {
ret = platform_driver_register(&s3c2440_i2c_driver);
if (ret)
platform_driver_unregister(&s3c2410_i2c_driver);
}
return ret;
}
static void __exit i2c_adap_s3c_exit(void)
{
platform_driver_unregister(&s3c2410_i2c_driver);
platform_driver_unregister(&s3c2440_i2c_driver);
}
module_init(i2c_adap_s3c_init);
module_exit(i2c_adap_s3c_exit);
MODULE_DESCRIPTION("S3C24XX I2C Bus driver");
MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
MODULE_LICENSE("GPL");
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