* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
-#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.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 <linux/cpufreq.h>
-#include <asm/hardware.h>
+#include <mach/hardware.h>
#include <asm/irq.h>
#include <asm/io.h>
-#include <asm/hardware/clock.h>
-#include <asm/arch/regs-gpio.h>
-#include <asm/arch/regs-iic.h>
-#include <asm/arch/iic.h>
+#include <mach/regs-gpio.h>
+#include <asm/plat-s3c/regs-iic.h>
+#include <asm/plat-s3c/iic.h>
/* i2c controller state */
unsigned int msg_idx;
unsigned int msg_ptr;
+ unsigned int tx_setup;
+
enum s3c24xx_i2c_state state;
+ unsigned long clkrate;
void __iomem *regs;
struct clk *clk;
struct resource *irq;
struct resource *ioarea;
struct i2c_adapter adap;
+
+#ifdef CONFIG_CPU_FREQ
+ struct notifier_block freq_transition;
+#endif
};
/* default platform data to use if not supplied in the platform_device
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);
+ /* delay here to ensure the data byte has gotten onto the bus
+ * before the transaction is started */
+
+ ndelay(i2c->tx_setup);
+
dev_dbg(i2c->dev, "iiccon, %08lx\n", iiccon);
writel(iiccon, i2c->regs + S3C2410_IICCON);
switch (i2c->state) {
case STATE_IDLE:
- dev_err(i2c->dev, "%s: called in STATE_IDLE\n", __FUNCTION__);
+ dev_err(i2c->dev, "%s: called in STATE_IDLE\n", __func__);
goto out;
break;
case STATE_STOP:
- dev_err(i2c->dev, "%s: called in STATE_STOP\n", __FUNCTION__);
+ dev_err(i2c->dev, "%s: called in STATE_STOP\n", __func__);
s3c24xx_i2c_disable_irq(i2c);
goto out_ack;
* bus, or started a new i2c message
*/
- if (iicstat & S3C2410_IICSTAT_LASTBIT &&
+ 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);
+ s3c24xx_i2c_stop(i2c, -ENXIO);
goto out_ack;
}
i2c->state = STATE_WRITE;
/* terminate the transfer if there is nothing to do
- * (used by the i2c probe to find devices */
+ * as this is used by the i2c probe to find devices. */
if (is_lastmsg(i2c) && i2c->msg->len == 0) {
s3c24xx_i2c_stop(i2c, 0);
* end of the message, and if so, work out what to do
*/
+ if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) {
+ if (iicstat & S3C2410_IICSTAT_LASTBIT) {
+ dev_dbg(i2c->dev, "WRITE: No Ack\n");
+
+ s3c24xx_i2c_stop(i2c, -ECONNREFUSED);
+ goto out_ack;
+ }
+ }
+
retry_write:
+
if (!is_msgend(i2c)) {
byte = i2c->msg->buf[i2c->msg_ptr++];
writeb(byte, i2c->regs + S3C2410_IICDS);
-
+
+ /* delay after writing the byte to allow the
+ * data setup time on the bus, as writing the
+ * data to the register causes the first bit
+ * to appear on SDA, and SCL will change as
+ * soon as the interrupt is acknowledged */
+
+ ndelay(i2c->tx_setup);
+
} else if (!is_lastmsg(i2c)) {
/* we need to go to the next i2c message */
* 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;
* top level IRQ servicing routine
*/
-static irqreturn_t s3c24xx_i2c_irq(int irqno, void *dev_id,
- struct pt_regs *regs)
+static irqreturn_t s3c24xx_i2c_irq(int irqno, void *dev_id)
{
struct s3c24xx_i2c *i2c = dev_id;
unsigned long status;
unsigned long timeout;
int ret;
+ if (!readl(i2c->regs + S3C2410_IICCON) & S3C2410_IICCON_IRQEN)
+ return -EIO;
+
ret = s3c24xx_i2c_set_master(i2c);
if (ret != 0) {
dev_err(i2c->dev, "cannot get bus (error %d)\n", ret);
/* i2c bus registration info */
-static struct i2c_algorithm s3c24xx_i2c_algorithm = {
+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 = {
+ .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,
+ .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
},
};
return (diff >= -2 && diff <= 2);
}
-/* s3c24xx_i2c_getdivisor
+/* s3c24xx_i2c_clockrate
*
* 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)
+static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
{
+ struct s3c2410_platform_i2c *pdata;
unsigned long clkin = clk_get_rate(i2c->clk);
-
unsigned int divs, div1;
+ 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",
+ 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) {
found:
*got = freq;
- *iicon |= (divs-1);
- *iicon |= (div1 == 512) ? S3C2410_IICCON_TXDIV_512 : 0;
+
+ iiccon = readl(i2c->regs + S3C2410_IICCON);
+ iiccon &= ~(S3C2410_IICCON_SCALEMASK | S3C2410_IICCON_TXDIV_512);
+ iiccon |= (divs-1);
+
+ if (div1 == 512)
+ iiccon |= S3C2410_IICCON_TXDIV_512;
+
+ writel(iiccon, i2c->regs + S3C2410_IICCON);
+
+ return 0;
+}
+
+#ifdef CONFIG_CPU_FREQ
+
+#define freq_to_i2c(_n) container_of(_n, struct s3c24xx_i2c, freq_transition)
+
+static int s3c24xx_i2c_cpufreq_transition(struct notifier_block *nb,
+ unsigned long val, void *data)
+{
+ struct s3c24xx_i2c *i2c = freq_to_i2c(nb);
+ unsigned long flags;
+ unsigned int got;
+ int delta_f;
+ int ret;
+
+ delta_f = clk_get_rate(i2c->clk) - i2c->clkrate;
+
+ /* if we're post-change and the input clock has slowed down
+ * or at pre-change and the clock is about to speed up, then
+ * adjust our clock rate. <0 is slow, >0 speedup.
+ */
+
+ if ((val == CPUFREQ_POSTCHANGE && delta_f < 0) ||
+ (val == CPUFREQ_PRECHANGE && delta_f > 0)) {
+ spin_lock_irqsave(&i2c->lock, flags);
+ ret = s3c24xx_i2c_clockrate(i2c, &got);
+ spin_unlock_irqrestore(&i2c->lock, flags);
+
+ if (ret < 0)
+ dev_err(i2c->dev, "cannot find frequency\n");
+ else
+ dev_info(i2c->dev, "setting freq %d\n", got);
+ }
+
+ return 0;
+}
+
+static inline int s3c24xx_i2c_register_cpufreq(struct s3c24xx_i2c *i2c)
+{
+ i2c->freq_transition.notifier_call = s3c24xx_i2c_cpufreq_transition;
+
+ return cpufreq_register_notifier(&i2c->freq_transition,
+ CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+static inline void s3c24xx_i2c_deregister_cpufreq(struct s3c24xx_i2c *i2c)
+{
+ cpufreq_unregister_notifier(&i2c->freq_transition,
+ CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+#else
+static inline int s3c24xx_i2c_register_cpufreq(struct s3c24xx_i2c *i2c)
+{
return 0;
}
+static inline void s3c24xx_i2c_deregister_cpufreq(struct s3c24xx_i2c *i2c)
+{
+}
+#endif
+
/* s3c24xx_i2c_init
*
* initialise the controller, set the IO lines and frequency
dev_info(i2c->dev, "slave address 0x%02x\n", pdata->slave_addr);
+ writel(iicon, i2c->regs + S3C2410_IICCON);
+
/* we need to work out the divisors for the clock... */
- if (s3c24xx_i2c_getdivisor(i2c, pdata, &iicon, &freq) != 0) {
+ if (s3c24xx_i2c_clockrate(i2c, &freq) != 0) {
+ writel(0, i2c->regs + S3C2410_IICCON);
dev_err(i2c->dev, "cannot meet bus frequency required\n");
return -EINVAL;
}
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 */
return 0;
}
-static void s3c24xx_i2c_free(struct s3c24xx_i2c *i2c)
-{
- if (i2c->clk != NULL && !IS_ERR(i2c->clk)) {
- clk_disable(i2c->clk);
- clk_unuse(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 device *dev)
+static int s3c24xx_i2c_probe(struct platform_device *pdev)
{
- struct platform_device *pdev = to_platform_device(dev);
struct s3c24xx_i2c *i2c = &s3c24xx_i2c;
+ struct s3c2410_platform_i2c *pdata;
struct resource *res;
int ret;
+ pdata = s3c24xx_i2c_get_platformdata(&pdev->dev);
+
/* find the clock and enable it */
- i2c->dev = dev;
- i2c->clk = clk_get(dev, "i2c");
+ i2c->dev = &pdev->dev;
+ i2c->clk = clk_get(&pdev->dev, "i2c");
if (IS_ERR(i2c->clk)) {
- dev_err(dev, "cannot get clock\n");
+ dev_err(&pdev->dev, "cannot get clock\n");
ret = -ENOENT;
- goto out;
+ goto err_noclk;
}
- dev_dbg(dev, "clock source %p\n", i2c->clk);
+ dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk);
- clk_use(i2c->clk);
clk_enable(i2c->clk);
/* map the registers */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (res == NULL) {
- dev_err(dev, "cannot find IO resource\n");
+ dev_err(&pdev->dev, "cannot find IO resource\n");
ret = -ENOENT;
- goto out;
+ goto err_clk;
}
i2c->ioarea = request_mem_region(res->start, (res->end-res->start)+1,
pdev->name);
if (i2c->ioarea == NULL) {
- dev_err(dev, "cannot request IO\n");
+ dev_err(&pdev->dev, "cannot request IO\n");
ret = -ENXIO;
- goto out;
+ goto err_clk;
}
i2c->regs = ioremap(res->start, (res->end-res->start)+1);
if (i2c->regs == NULL) {
- dev_err(dev, "cannot map IO\n");
+ dev_err(&pdev->dev, "cannot map IO\n");
ret = -ENXIO;
- goto out;
+ goto err_ioarea;
}
- dev_dbg(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 */
i2c->adap.algo_data = i2c;
- i2c->adap.dev.parent = dev;
+ i2c->adap.dev.parent = &pdev->dev;
/* initialise the i2c controller */
ret = s3c24xx_i2c_init(i2c);
if (ret != 0)
- goto out;
+ goto err_iomap;
/* 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(dev, "cannot find IRQ\n");
+ dev_err(&pdev->dev, "cannot find IRQ\n");
ret = -ENOENT;
- goto out;
+ goto err_iomap;
}
- ret = request_irq(res->start, s3c24xx_i2c_irq, SA_INTERRUPT,
+ ret = request_irq(res->start, s3c24xx_i2c_irq, IRQF_DISABLED,
pdev->name, i2c);
if (ret != 0) {
- dev_err(dev, "cannot claim IRQ\n");
- goto out;
+ dev_err(&pdev->dev, "cannot claim IRQ\n");
+ goto err_iomap;
}
i2c->irq = res;
- dev_dbg(dev, "irq resource %p (%ld)\n", res, res->start);
+ dev_dbg(&pdev->dev, "irq resource %p (%lu)\n", res,
+ (unsigned long)res->start);
- ret = i2c_add_adapter(&i2c->adap);
+ ret = s3c24xx_i2c_register_cpufreq(i2c);
if (ret < 0) {
- dev_err(dev, "failed to add bus to i2c core\n");
- goto out;
+ dev_err(&pdev->dev, "failed to register cpufreq notifier\n");
+ goto err_irq;
+ }
+
+ /* Note, previous versions of the driver used i2c_add_adapter()
+ * to add the bus at any number. We now pass the bus number via
+ * the platform data, so if unset it will now default to always
+ * being bus 0.
+ */
+
+ i2c->adap.nr = pdata->bus_num;
+
+ ret = i2c_add_numbered_adapter(&i2c->adap);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to add bus to i2c core\n");
+ goto err_cpufreq;
}
- dev_set_drvdata(dev, i2c);
+ platform_set_drvdata(pdev, i2c);
- dev_info(dev, "%s: S3C I2C adapter\n", i2c->adap.dev.bus_id);
+ dev_info(&pdev->dev, "%s: S3C I2C adapter\n", i2c->adap.dev.bus_id);
+ return 0;
- out:
- if (ret < 0)
- s3c24xx_i2c_free(i2c);
+ err_cpufreq:
+ s3c24xx_i2c_deregister_cpufreq(i2c);
+ err_irq:
+ free_irq(i2c->irq->start, i2c);
+
+ err_iomap:
+ iounmap(i2c->regs);
+
+ err_ioarea:
+ release_resource(i2c->ioarea);
+ kfree(i2c->ioarea);
+
+ err_clk:
+ clk_disable(i2c->clk);
+ clk_put(i2c->clk);
+
+ err_noclk:
return ret;
}
* called when device is removed from the bus
*/
-static int s3c24xx_i2c_remove(struct device *dev)
+static int s3c24xx_i2c_remove(struct platform_device *pdev)
{
- struct s3c24xx_i2c *i2c = dev_get_drvdata(dev);
-
- if (i2c != NULL) {
- s3c24xx_i2c_free(i2c);
- dev_set_drvdata(dev, NULL);
- }
+ struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
+
+ s3c24xx_i2c_deregister_cpufreq(i2c);
+
+ i2c_del_adapter(&i2c->adap);
+ free_irq(i2c->irq->start, i2c);
+
+ clk_disable(i2c->clk);
+ clk_put(i2c->clk);
+
+ iounmap(i2c->regs);
+
+ release_resource(i2c->ioarea);
+ kfree(i2c->ioarea);
return 0;
}
#ifdef CONFIG_PM
-static int s3c24xx_i2c_resume(struct device *dev)
+static int s3c24xx_i2c_resume(struct platform_device *dev)
{
- struct s3c24xx_i2c *i2c = dev_get_drvdata(dev);
+ struct s3c24xx_i2c *i2c = platform_get_drvdata(dev);
if (i2c != NULL)
s3c24xx_i2c_init(i2c);
/* device driver for platform bus bits */
-static struct device_driver s3c2410_i2c_driver = {
- .owner = THIS_MODULE,
- .name = "s3c2410-i2c",
- .bus = &platform_bus_type,
+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 device_driver s3c2440_i2c_driver = {
- .owner = THIS_MODULE,
- .name = "s3c2440-i2c",
- .bus = &platform_bus_type,
+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 = driver_register(&s3c2410_i2c_driver);
+ ret = platform_driver_register(&s3c2410_i2c_driver);
if (ret == 0) {
- ret = driver_register(&s3c2440_i2c_driver);
+ ret = platform_driver_register(&s3c2440_i2c_driver);
if (ret)
- driver_unregister(&s3c2410_i2c_driver);
+ platform_driver_unregister(&s3c2410_i2c_driver);
}
return ret;
static void __exit i2c_adap_s3c_exit(void)
{
- driver_unregister(&s3c2410_i2c_driver);
- driver_unregister(&s3c2440_i2c_driver);
+ platform_driver_unregister(&s3c2410_i2c_driver);
+ platform_driver_unregister(&s3c2440_i2c_driver);
}
module_init(i2c_adap_s3c_init);
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