This patch adds polling mode support for i2c s3c-2410 driver.
The I2C_SATAPHY controller lacks an interrupt line but the s3c-2410 driver
is interrupt driven. Hence this support is required for functioning
of the I2C_SATAPHY controller.
Signed-off-by: Vasanth Ananthan <vasanth.a@xxxxxxxxxxx>
---
drivers/i2c/busses/i2c-s3c2410.c | 84 +++++++++++++++++++++++++++++---------
1 files changed, 65 insertions(+), 19 deletions(-)
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index 5ae3b02..699b530 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -48,6 +48,7 @@
#define QUIRK_S3C2440 (1 << 0)
#define QUIRK_HDMIPHY (1 << 1)
#define QUIRK_NO_GPIO (1 << 2)
+#define QUIRK_SATAPHY (1 << 3)
/* i2c controller state */
enum s3c24xx_i2c_state {
@@ -102,10 +103,14 @@ static struct platform_device_id s3c24xx_driver_ids[] = {
};
MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
+static int i2c_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat);
+
#ifdef CONFIG_OF
static const struct of_device_id s3c24xx_i2c_match[] = {
{ .compatible = "samsung,s3c2410-i2c", .data = (void *)0 },
{ .compatible = "samsung,s3c2440-i2c", .data = (void *)QUIRK_S3C2440 },
+ { .compatible = "samsung,s3c2440-sataphy-i2c",
+ .data = (void *)(QUIRK_S3C2440|QUIRK_SATAPHY|QUIRK_NO_GPIO) },
{ .compatible = "samsung,s3c2440-hdmiphy-i2c",
.data = (void *)(QUIRK_S3C2440 | QUIRK_HDMIPHY | QUIRK_NO_GPIO) },
{},
@@ -146,7 +151,8 @@ static inline void s3c24xx_i2c_master_complete(struct s3c24xx_i2c *i2c, int ret)
if (ret)
i2c->msg_idx = ret;
- wake_up(&i2c->wait);
+ if (!(i2c->quirks & QUIRK_SATAPHY))
+ wake_up(&i2c->wait);
}
static inline void s3c24xx_i2c_disable_ack(struct s3c24xx_i2c *i2c)
@@ -184,6 +190,21 @@ static inline void s3c24xx_i2c_enable_irq(struct s3c24xx_i2c *i2c)
}
+static bool is_ack(struct s3c24xx_i2c *i2c)
+{
+ u32 time_out = i2c->tx_setup;
+ while (--time_out) {
+ if (readl(i2c->regs + S3C2410_IICCON)
+ & S3C2410_IICCON_IRQPEND) {
+ if (!(readl(i2c->regs + S3C2410_IICSTAT)
+ & S3C2410_IICSTAT_LASTBIT))
+ return true;
+ }
+ udelay(time_out);
+ }
+ return false;
+}
+
/* s3c24xx_i2c_message_start
*
* put the start of a message onto the bus
@@ -227,6 +248,21 @@ static void s3c24xx_i2c_message_start(struct s3c24xx_i2c *i2c,
stat |= S3C2410_IICSTAT_START;
writel(stat, i2c->regs + S3C2410_IICSTAT);
+
+ if (i2c->quirks & QUIRK_SATAPHY) {
+
+ while ((i2c->msg_num != 0) && is_ack(i2c)) {
+
+ i2c_s3c_irq_nextbyte(i2c, stat);
+
+ stat = readl(i2c->regs + S3C2410_IICSTAT);
+ if (stat & S3C2410_IICSTAT_ARBITR)
+ dev_err(i2c->dev, "deal with arbitration loss\n");
+
+ }
+
+ }
+
}
static inline void s3c24xx_i2c_stop(struct s3c24xx_i2c *i2c, int ret)
@@ -552,22 +588,27 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *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 (!(i2c->quirks & QUIRK_SATAPHY)) {
- if (timeout == 0)
- dev_dbg(i2c->dev, "timeout\n");
- else if (ret != num)
- dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret);
+ timeout = wait_event_timeout(i2c->wait,
+ i2c->msg_num == 0, HZ * 5);
- /* ensure the stop has been through the bus */
+ /* 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 */
+ }
dev_dbg(i2c->dev, "waiting for bus idle\n");
+
/* first, try busy waiting briefly */
do {
cpu_relax();
@@ -710,6 +751,9 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
if (div1 == 512)
iiccon |= S3C2410_IICCON_TXDIV_512;
+ if (i2c->quirks & QUIRK_SATAPHY)
+ iiccon |= S3C2410_IICCON_SCALE(2);
+
writel(iiccon, i2c->regs + S3C2410_IICCON);
if (i2c->quirks & QUIRK_S3C2440) {
@@ -1023,18 +1067,20 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
* ensure no current IRQs pending
*/
- i2c->irq = ret = platform_get_irq(pdev, 0);
- if (ret <= 0) {
- dev_err(&pdev->dev, "cannot find IRQ\n");
- goto err_iomap;
- }
+ if (!(i2c->quirks & QUIRK_SATAPHY)) {
+ i2c->irq = ret = platform_get_irq(pdev, 0);
+ if (ret <= 0) {
+ dev_err(&pdev->dev, "cannot find IRQ\n");
+ goto err_iomap;
+ }
- ret = request_irq(i2c->irq, s3c24xx_i2c_irq, 0,
+ ret = request_irq(i2c->irq, s3c24xx_i2c_irq, 0,
dev_name(&pdev->dev), i2c);
- if (ret != 0) {
- dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq);
- goto err_iomap;
+ if (ret != 0) {
+ dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq);
+ goto err_iomap;
+ }
}
ret = s3c24xx_i2c_register_cpufreq(i2c);
--
1.7.5.4
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