[PATCH 4/6] ARM: S3C2410: I2C driver polling mode support

From: Tomasz Figa <hidden>
Date: 2012-10-12 22:36:46
Also in: linux-ide, linux-samsung-soc

Hi,

On Tuesday 09 of October 2012 17:18:50 Vasanth Ananthan wrote:

quoted hunk ↗ jump to hunk

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 <redacted>
---
 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) },

nitpick: Please insert spaces around bitwise OR operators.

quoted hunk ↗ jump to hunk

 	{ .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;

nitpick: Separate local variable declaration from code with a blank line.

+	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);
+	}

nitpick: Here a blank line would be fine.

quoted hunk ↗ jump to hunk

+	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) {
+

nitpick: Unnecessary blank line.

+		while ((i2c->msg_num != 0) && is_ack(i2c)) {
+

Same here.

+			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");
+

Same here.

+		}
+

Same here.

+	}
+

Same here.

Best regards,
Tomasz Figa

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