/* linux/drivers/i2c/busses/i2c-s3c2410.c
*
- * Copyright (C) 2004,2005 Simtec Electronics
+ * Copyright (C) 2004,2005,2009 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*
* S3C2410 I2C Controller
#include <linux/clk.h>
#include <linux/cpufreq.h>
-#include <mach/hardware.h>
#include <asm/irq.h>
#include <asm/io.h>
-#include <mach/regs-gpio.h>
#include <plat/regs-iic.h>
#include <plat/iic.h>
STATE_STOP
};
+enum s3c24xx_i2c_type {
+ TYPE_S3C2410,
+ TYPE_S3C2440,
+};
+
struct s3c24xx_i2c {
spinlock_t lock;
wait_queue_head_t wait;
+ unsigned int suspended:1;
struct i2c_msg *msg;
unsigned int msg_num;
unsigned int msg_ptr;
unsigned int tx_setup;
+ unsigned int irq;
enum s3c24xx_i2c_state state;
unsigned long clkrate;
void __iomem *regs;
struct clk *clk;
struct device *dev;
- struct resource *irq;
struct resource *ioarea;
struct i2c_adapter adap;
#endif
};
-/* 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,
-};
+/* default platform data removed, dev should always carry data. */
/* s3c24xx_i2c_is2440()
*
static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c)
{
struct platform_device *pdev = to_platform_device(i2c->dev);
+ enum s3c24xx_i2c_type type;
- 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;
+ type = platform_get_device_id(pdev)->driver_data;
+ return type == TYPE_S3C2440;
}
/* s3c24xx_i2c_master_complete
i2c->msg_ptr = 0;
i2c->msg = NULL;
- i2c->msg_idx ++;
+ i2c->msg_idx++;
i2c->msg_num = 0;
if (ret)
i2c->msg_idx = ret;
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
+ * put the start of a message onto the bus
*/
-static void s3c24xx_i2c_message_start(struct s3c24xx_i2c *i2c,
+static void s3c24xx_i2c_message_start(struct s3c24xx_i2c *i2c,
struct i2c_msg *msg)
{
unsigned int addr = (msg->addr & 0x7f) << 1;
if (msg->flags & I2C_M_REV_DIR_ADDR)
addr ^= 1;
- // todo - check for wether ack wanted or not
+ /* 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 here to ensure the data byte has gotten onto the bus
* before the transaction is started */
dev_dbg(i2c->dev, "iiccon, %08lx\n", iiccon);
writel(iiccon, i2c->regs + S3C2410_IICCON);
-
- stat |= S3C2410_IICSTAT_START;
+
+ stat |= S3C2410_IICSTAT_START;
writel(stat, i2c->regs + S3C2410_IICSTAT);
}
dev_dbg(i2c->dev, "STOP\n");
/* stop the transfer */
- iicstat &= ~ S3C2410_IICSTAT_START;
+ 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);
}
/* is_lastmsg()
*
- * returns TRUE if the current message is the last in the set
+ * returns TRUE if the current message is the last in the set
*/
static inline int is_lastmsg(struct s3c24xx_i2c *i2c)
case STATE_STOP:
dev_err(i2c->dev, "%s: called in STATE_STOP\n", __func__);
- s3c24xx_i2c_disable_irq(i2c);
+ 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... */
if (i2c->state == STATE_READ)
goto prepare_read;
- /* fall through to the write state, as we will need to
+ /* fall through to the write state, as we will need to
* send a byte as well */
case STATE_WRITE:
}
}
- retry_write:
+ retry_write:
if (!is_msgend(i2c)) {
byte = i2c->msg->buf[i2c->msg_ptr++];
dev_dbg(i2c->dev, "WRITE: Next Message\n");
i2c->msg_ptr = 0;
- i2c->msg_idx ++;
+ i2c->msg_idx++;
i2c->msg++;
-
+
/* check to see if we need to do another message */
if (i2c->msg->flags & I2C_M_NOSTART) {
goto retry_write;
} else {
-
/* send the new start */
s3c24xx_i2c_message_start(i2c, i2c->msg);
i2c->state = STATE_START;
break;
case STATE_READ:
- /* we have a byte of data in the data register, do
+ /* 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
*/
byte = readb(i2c->regs + S3C2410_IICDS);
i2c->msg->buf[i2c->msg_ptr++] = byte;
- prepare_read:
+ 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 */
/* acknowlegde the IRQ and get back on with the work */
out_ack:
- tmp = readl(i2c->regs + S3C2410_IICCON);
+ tmp = readl(i2c->regs + S3C2410_IICCON);
tmp &= ~S3C2410_IICCON_IRQPEND;
writel(tmp, i2c->regs + S3C2410_IICCON);
out:
status = readl(i2c->regs + S3C2410_IICSTAT);
if (status & S3C2410_IICSTAT_ARBITR) {
- // deal with arbitration loss
+ /* 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 = 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 */
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;
}
* this starts an i2c transfer
*/
-static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c, struct i2c_msg *msgs, int num)
+static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c,
+ struct i2c_msg *msgs, int num)
{
unsigned long timeout;
int ret;
- if (!readl(i2c->regs + S3C2410_IICCON) & S3C2410_IICCON_IRQEN)
+ if (i2c->suspended)
return -EIO;
ret = s3c24xx_i2c_set_master(i2c);
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
+ /* having these next two as dev_err() makes life very
* noisy when doing an i2cdetect */
if (timeout == 0)
.functionality = s3c24xx_i2c_func,
};
-static struct s3c24xx_i2c s3c24xx_i2c = {
- .lock = __SPIN_LOCK_UNLOCKED(s3c24xx_i2c.lock),
- .wait = __WAIT_QUEUE_HEAD_INITIALIZER(s3c24xx_i2c.wait),
- .tx_setup = 50,
- .adap = {
- .name = "s3c2410-i2c",
- .owner = THIS_MODULE,
- .algo = &s3c24xx_i2c_algorithm,
- .retries = 2,
- .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
- },
-};
-
/* s3c24xx_i2c_calcdivisor
*
* return the divisor settings for a given frequency
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_clockrate
*
* work out a divisor for the user requested frequency setting,
static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
{
- struct s3c2410_platform_i2c *pdata;
+ struct s3c2410_platform_i2c *pdata = i2c->dev->platform_data;
unsigned long clkin = clk_get_rate(i2c->clk);
unsigned int divs, div1;
+ unsigned long target_frequency;
u32 iiccon;
int freq;
- int start, end;
i2c->clkrate = clkin;
-
- pdata = s3c24xx_i2c_get_platformdata(i2c->adap.dev.parent);
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... */
+ dev_dbg(i2c->dev, "pdata desired frequency %lu\n", pdata->frequency);
- start = (pdata->max_freq == 0) ? pdata->bus_freq : pdata->max_freq;
- end = pdata->min_freq;
+ target_frequency = pdata->frequency ? pdata->frequency : 100000;
- start /= 1000;
- end /= 1000;
+ target_frequency /= 1000; /* Target frequency now in KHz */
- /* search loop... */
+ freq = s3c24xx_i2c_calcdivisor(clkin, target_frequency, &div1, &divs);
- for (; start > end; start--) {
- freq = s3c24xx_i2c_calcdivisor(clkin, start, &div1, &divs);
- if (freq_acceptable(freq, start))
- goto found;
+ if (freq > target_frequency) {
+ dev_err(i2c->dev,
+ "Unable to achieve desired frequency %luKHz." \
+ " Lowest achievable %dKHz\n", target_frequency, freq);
+ return -EINVAL;
}
- /* cannot find frequency spec */
-
- return -EINVAL;
-
- found:
*got = freq;
iiccon = readl(i2c->regs + S3C2410_IICCON);
writel(iiccon, i2c->regs + S3C2410_IICCON);
+ if (s3c24xx_i2c_is2440(i2c)) {
+ unsigned long sda_delay;
+
+ if (pdata->sda_delay) {
+ sda_delay = (freq / 1000) * pdata->sda_delay;
+ sda_delay /= 1000000;
+ sda_delay = DIV_ROUND_UP(sda_delay, 5);
+ if (sda_delay > 3)
+ sda_delay = 3;
+ sda_delay |= S3C2410_IICLC_FILTER_ON;
+ } else
+ sda_delay = 0;
+
+ dev_dbg(i2c->dev, "IICLC=%08lx\n", sda_delay);
+ writel(sda_delay, i2c->regs + S3C2440_IICLC);
+ }
+
return 0;
}
/* s3c24xx_i2c_init
*
- * initialise the controller, set the IO lines and frequency
+ * initialise the controller, set the IO lines and frequency
*/
static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
/* get the plafrom data */
- pdata = s3c24xx_i2c_get_platformdata(i2c->adap.dev.parent);
+ pdata = i2c->dev->platform_data;
/* inititalise the gpio */
- s3c2410_gpio_cfgpin(S3C2410_GPE15, S3C2410_GPE15_IICSDA);
- s3c2410_gpio_cfgpin(S3C2410_GPE14, S3C2410_GPE14_IICSCL);
+ if (pdata->cfg_gpio)
+ pdata->cfg_gpio(to_platform_device(i2c->dev));
/* write slave address */
-
+
writeb(pdata->slave_addr, i2c->regs + S3C2410_IICADD);
dev_info(i2c->dev, "slave address 0x%02x\n", pdata->slave_addr);
dev_info(i2c->dev, "bus frequency set to %d KHz\n", freq);
dev_dbg(i2c->dev, "S3C2410_IICCON=0x%02lx\n", iicon);
- /* 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 int s3c24xx_i2c_probe(struct platform_device *pdev)
{
- struct s3c24xx_i2c *i2c = &s3c24xx_i2c;
+ struct s3c24xx_i2c *i2c;
struct s3c2410_platform_i2c *pdata;
struct resource *res;
int ret;
- pdata = s3c24xx_i2c_get_platformdata(&pdev->dev);
+ pdata = pdev->dev.platform_data;
+ if (!pdata) {
+ dev_err(&pdev->dev, "no platform data\n");
+ return -EINVAL;
+ }
+
+ i2c = kzalloc(sizeof(struct s3c24xx_i2c), GFP_KERNEL);
+ if (!i2c) {
+ dev_err(&pdev->dev, "no memory for state\n");
+ return -ENOMEM;
+ }
+
+ strlcpy(i2c->adap.name, "s3c2410-i2c", sizeof(i2c->adap.name));
+ i2c->adap.owner = THIS_MODULE;
+ i2c->adap.algo = &s3c24xx_i2c_algorithm;
+ i2c->adap.retries = 2;
+ i2c->adap.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+ i2c->tx_setup = 50;
+
+ spin_lock_init(&i2c->lock);
+ init_waitqueue_head(&i2c->wait);
/* find the clock and enable it */
goto err_clk;
}
- i2c->ioarea = request_mem_region(res->start, (res->end-res->start)+1,
+ i2c->ioarea = request_mem_region(res->start, resource_size(res),
pdev->name);
if (i2c->ioarea == NULL) {
goto err_clk;
}
- i2c->regs = ioremap(res->start, (res->end-res->start)+1);
+ i2c->regs = ioremap(res->start, resource_size(res));
if (i2c->regs == NULL) {
dev_err(&pdev->dev, "cannot map IO\n");
goto err_ioarea;
}
- dev_dbg(&pdev->dev, "registers %p (%p, %p)\n", i2c->regs, i2c->ioarea, res);
+ dev_dbg(&pdev->dev, "registers %p (%p, %p)\n",
+ i2c->regs, i2c->ioarea, res);
/* setup info block for the i2c core */
goto err_iomap;
/* find the IRQ for this unit (note, this relies on the init call to
- * ensure no current IRQs pending
+ * ensure no current IRQs pending
*/
- res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
- if (res == NULL) {
+ i2c->irq = ret = platform_get_irq(pdev, 0);
+ if (ret <= 0) {
dev_err(&pdev->dev, "cannot find IRQ\n");
- ret = -ENOENT;
goto err_iomap;
}
- ret = request_irq(res->start, s3c24xx_i2c_irq, IRQF_DISABLED,
- pdev->name, i2c);
+ ret = request_irq(i2c->irq, s3c24xx_i2c_irq, IRQF_DISABLED,
+ dev_name(&pdev->dev), i2c);
if (ret != 0) {
- dev_err(&pdev->dev, "cannot claim IRQ\n");
+ dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq);
goto err_iomap;
}
- i2c->irq = res;
-
- dev_dbg(&pdev->dev, "irq resource %p (%lu)\n", res,
- (unsigned long)res->start);
-
ret = s3c24xx_i2c_register_cpufreq(i2c);
if (ret < 0) {
dev_err(&pdev->dev, "failed to register cpufreq notifier\n");
platform_set_drvdata(pdev, i2c);
- dev_info(&pdev->dev, "%s: S3C I2C adapter\n", i2c->adap.dev.bus_id);
+ dev_info(&pdev->dev, "%s: S3C I2C adapter\n", dev_name(&i2c->adap.dev));
return 0;
err_cpufreq:
s3c24xx_i2c_deregister_cpufreq(i2c);
err_irq:
- free_irq(i2c->irq->start, i2c);
+ free_irq(i2c->irq, i2c);
err_iomap:
iounmap(i2c->regs);
clk_put(i2c->clk);
err_noclk:
+ kfree(i2c);
return ret;
}
s3c24xx_i2c_deregister_cpufreq(i2c);
i2c_del_adapter(&i2c->adap);
- free_irq(i2c->irq->start, i2c);
+ free_irq(i2c->irq, i2c);
clk_disable(i2c->clk);
clk_put(i2c->clk);
release_resource(i2c->ioarea);
kfree(i2c->ioarea);
+ kfree(i2c);
return 0;
}
#ifdef CONFIG_PM
-static int s3c24xx_i2c_resume(struct platform_device *dev)
+static int s3c24xx_i2c_suspend_noirq(struct device *dev)
{
- struct s3c24xx_i2c *i2c = platform_get_drvdata(dev);
+ struct platform_device *pdev = to_platform_device(dev);
+ struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
- if (i2c != NULL)
- s3c24xx_i2c_init(i2c);
+ i2c->suspended = 1;
return 0;
}
+static int s3c24xx_i2c_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
+
+ i2c->suspended = 0;
+ s3c24xx_i2c_init(i2c);
+
+ return 0;
+}
+
+static const struct dev_pm_ops s3c24xx_i2c_dev_pm_ops = {
+ .suspend_noirq = s3c24xx_i2c_suspend_noirq,
+ .resume = s3c24xx_i2c_resume,
+};
+
+#define S3C24XX_DEV_PM_OPS (&s3c24xx_i2c_dev_pm_ops)
#else
-#define s3c24xx_i2c_resume NULL
+#define S3C24XX_DEV_PM_OPS 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_device_id s3c24xx_driver_ids[] = {
+ {
+ .name = "s3c2410-i2c",
+ .driver_data = TYPE_S3C2410,
+ }, {
+ .name = "s3c2440-i2c",
+ .driver_data = TYPE_S3C2440,
+ }, { },
};
+MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
-static struct platform_driver s3c2440_i2c_driver = {
+static struct platform_driver s3c24xx_i2c_driver = {
.probe = s3c24xx_i2c_probe,
.remove = s3c24xx_i2c_remove,
- .resume = s3c24xx_i2c_resume,
+ .id_table = s3c24xx_driver_ids,
.driver = {
.owner = THIS_MODULE,
- .name = "s3c2440-i2c",
+ .name = "s3c-i2c",
+ .pm = S3C24XX_DEV_PM_OPS,
},
};
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;
+ return platform_driver_register(&s3c24xx_i2c_driver);
}
+subsys_initcall(i2c_adap_s3c_init);
static void __exit i2c_adap_s3c_exit(void)
{
- platform_driver_unregister(&s3c2410_i2c_driver);
- platform_driver_unregister(&s3c2440_i2c_driver);
+ platform_driver_unregister(&s3c24xx_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");
-MODULE_ALIAS("platform:s3c2410-i2c");
-MODULE_ALIAS("platform:s3c2440-i2c");
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff