Hi Tomasz,

Hi Pankaj,

On 10.05.2014 09:20, Pankaj Dubey wrote:

quoted

Let's handle i2c interrupt re-configuration in i2c driver. This will
help us in removing some soc specific checks from machine files.
Since only Exynos5250, and Exynos5420 need to do this, added syscon
based phandle to i2c device nodes of respective SoC DT files.
Also handle saving and restoring of SYS_I2C_CFG register during
suspend and resume of i2c driver. This will help in removing soc
specific check from mach-exynos/pm.c.

CC: Rob Herring <robh+dt@kernel.org>
CC: Randy Dunlap <redacted>
CC: Wolfram Sang <redacted>
CC: Russell King <redacted>
CC: devicetree at vger.kernel.org
CC: linux-doc at vger.kernel.org
CC: linux-i2c at vger.kernel.org
Signed-off-by: Pankaj Dubey <redacted>
---
 .../devicetree/bindings/arm/samsung/sysreg.txt     |    1 +
 arch/arm/boot/dts/exynos5.dtsi                     |    5 +++
 arch/arm/boot/dts/exynos5250.dtsi                  |    4 +++
 arch/arm/boot/dts/exynos5420.dtsi                  |    4 +++

What about Exynos5410 and Exynos5800?

OK, I will check user manuals of these two SoCs and if required will update.

quoted

 drivers/i2c/busses/i2c-s3c2410.c                   |   32

++++++++++++++++++++

quoted

 5 files changed, 46 insertions(+)

[snip]

quoted

diff --git a/drivers/i2c/busses/i2c-s3c2410.c

b/drivers/i2c/busses/i2c-s3c2410.c
index ae44910..e707062 100644

--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c

@@ -39,6 +39,8 @@
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/pinctrl/consumer.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>

 #include <asm/irq.h>

@@ -91,6 +93,9 @@
 /* Max time to wait for bus to become idle after a xfer (in us) */
 #define S3C2410_IDLE_TIMEOUT	5000

+/* Exynos5 Sysreg offset */
+#define EXYNOS5_SYS_I2C_CFG	0x0234
+
 /* i2c controller state */
 enum s3c24xx_i2c_state {
 	STATE_IDLE,

@@ -127,6 +132,8 @@ struct s3c24xx_i2c {  #if

defined(CONFIG_ARM_S3C24XX_CPUFREQ)
 	struct notifier_block	freq_transition;
 #endif
+	struct regmap		*sysreg;
+	unsigned int		sys_i2s_cfg;

typo: s/i2s/i2c/

Oops, sorry I will correct this. 

quoted

 };

 static struct platform_device_id s3c24xx_driver_ids[] = { @@ -1075,6
+1082,8 @@ static void  s3c24xx_i2c_parse_dt(struct device_node *np,
struct s3c24xx_i2c *i2c)  {
 	struct s3c2410_platform_i2c *pdata = i2c->pdata;
+	u32 val = 0;
+	int id;

 	if (!np)
 		return;

@@ -1084,6 +1093,23 @@ s3c24xx_i2c_parse_dt(struct device_node *np,

struct

s3c24xx_i2c *i2c)

quoted

 	of_property_read_u32(np, "samsung,i2c-slave-addr",

&pdata->slave_addr);

quoted

 	of_property_read_u32(np, "samsung,i2c-max-bus-freq",
 				(u32 *)&pdata->frequency);
+	/*
+	 * Exynos5's legacy i2c controller and new high speed i2c
+	 * controller have muxed interrupt sources. By default the

What do you mean by "by default"? Is it a setting from the bootloader or

reset value?

It's a reset value.

Probably to ensure that the mux is set correctly, same thing should be

also added to

hsi2c driver.

quoted

+	 * interrupts for 4-channel HS-I2C controller are enabled.
+	 * If node for first four channels of legacy i2c controller
+	 * are available then re-configure the interrupts via the
+	 * system register.
+	 */
+	id = of_alias_get_id(np, "i2c");
+	i2c->sysreg = syscon_regmap_lookup_by_phandle(np,
+			"samsung,syscon-phandle");
+	if (IS_ERR(i2c->sysreg)) {
+		/* As this is not compulsory do not return error */
+		pr_info("i2c-%d skipping re-configuration of interrutps\n",

id);

quoted

+		return;
+	}
+	regmap_update_bits(i2c->sysreg, EXYNOS5_SYS_I2C_CFG, BIT(id), val);

As Wolfram pointed, val can be replaced with immediate 0 here.

OK, I will take care as per suggestion.

quoted

 }
 #else
 static void

@@ -1268,6 +1294,9 @@ static int s3c24xx_i2c_suspend_noirq(struct

device *dev)

 	i2c->suspended = 1;

+	if (!IS_ERR(i2c->sysreg))
+		regmap_read(i2c->sysreg, EXYNOS5_SYS_I2C_CFG, &i2c-
sys_i2s_cfg);
+
 	return 0;
 }

@@ -1276,6 +1305,9 @@ static int s3c24xx_i2c_resume(struct device *dev)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);

+	if (!IS_ERR(i2c->sysreg))
+		regmap_write(i2c->sysreg, i2c->sys_i2s_cfg,

EXYNOS5_SYS_I2C_CFG);

According to include/linux/regmap.h:

int regmap_write(struct regmap *map, unsigned int reg, unsigned int val);

So in your code reg is swapped with val.

Yes. I will correct this.

Best regards,
Tomasz