[PATCH v4 1/2] i2c: s3c2410: Handle i2c sys_cfg register in i2c driver
Pankaj Dubey
pankaj.dubey at samsung.com
Thu Oct 30 01:04:29 PDT 2014
Let's handle i2c interrupt re-configuration in i2c driver. This will
help us in removing some soc specific checks from machine files and
will help in removing static iomapping of SYS register in exynos.c
Since only Exynos5250, and Exynos5420 has i2c nodes in DT, 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.
CC: Rob Herring <robh+dt at kernel.org>
CC: Randy Dunlap <rdunlap at infradead.org>
CC: Wolfram Sang <wsa at the-dreams.de>
CC: Russell King <linux at arm.linux.org.uk>
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 <pankaj.dubey at samsung.com>
---
.../devicetree/bindings/i2c/i2c-s3c2410.txt | 1 +
arch/arm/boot/dts/exynos5250.dtsi | 4 +++
arch/arm/boot/dts/exynos5420.dtsi | 4 +++
drivers/i2c/busses/i2c-s3c2410.c | 31 ++++++++++++++++++++
4 files changed, 40 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt b/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt
index 278de8e..89b3250 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt
@@ -32,6 +32,7 @@ Optional properties:
specified, default value is 0.
- samsung,i2c-max-bus-freq: Desired frequency in Hz of the bus. If not
specified, the default value in Hz is 100000.
+ - samsung,sysreg-phandle - handle to syscon used to control the system registers
Example:
diff --git a/arch/arm/boot/dts/exynos5250.dtsi b/arch/arm/boot/dts/exynos5250.dtsi
index 012b021..6a32d50 100644
--- a/arch/arm/boot/dts/exynos5250.dtsi
+++ b/arch/arm/boot/dts/exynos5250.dtsi
@@ -293,6 +293,7 @@
clock-names = "i2c";
pinctrl-names = "default";
pinctrl-0 = <&i2c0_bus>;
+ samsung,sysreg-phandle = <&sysreg_system_controller>;
status = "disabled";
};
@@ -306,6 +307,7 @@
clock-names = "i2c";
pinctrl-names = "default";
pinctrl-0 = <&i2c1_bus>;
+ samsung,sysreg-phandle = <&sysreg_system_controller>;
status = "disabled";
};
@@ -319,6 +321,7 @@
clock-names = "i2c";
pinctrl-names = "default";
pinctrl-0 = <&i2c2_bus>;
+ samsung,sysreg-phandle = <&sysreg_system_controller>;
status = "disabled";
};
@@ -332,6 +335,7 @@
clock-names = "i2c";
pinctrl-names = "default";
pinctrl-0 = <&i2c3_bus>;
+ samsung,sysreg-phandle = <&sysreg_system_controller>;
status = "disabled";
};
diff --git a/arch/arm/boot/dts/exynos5420.dtsi b/arch/arm/boot/dts/exynos5420.dtsi
index 8617a03..90bf401 100644
--- a/arch/arm/boot/dts/exynos5420.dtsi
+++ b/arch/arm/boot/dts/exynos5420.dtsi
@@ -560,6 +560,7 @@
clock-names = "i2c";
pinctrl-names = "default";
pinctrl-0 = <&i2c0_bus>;
+ samsung,sysreg-phandle = <&sysreg_system_controller>;
status = "disabled";
};
@@ -573,6 +574,7 @@
clock-names = "i2c";
pinctrl-names = "default";
pinctrl-0 = <&i2c1_bus>;
+ samsung,sysreg-phandle = <&sysreg_system_controller>;
status = "disabled";
};
@@ -586,6 +588,7 @@
clock-names = "i2c";
pinctrl-names = "default";
pinctrl-0 = <&i2c2_bus>;
+ samsung,sysreg-phandle = <&sysreg_system_controller>;
status = "disabled";
};
@@ -599,6 +602,7 @@
clock-names = "i2c";
pinctrl-names = "default";
pinctrl-0 = <&i2c3_bus>;
+ samsung,sysreg-phandle = <&sysreg_system_controller>;
status = "disabled";
};
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index e3b0337..a46435a 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_i2c_cfg;
};
static struct platform_device_id s3c24xx_driver_ids[] = {
@@ -1075,6 +1082,7 @@ static void
s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c)
{
struct s3c2410_platform_i2c *pdata = i2c->pdata;
+ int id;
if (!np)
return;
@@ -1084,6 +1092,23 @@ s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c)
of_property_read_u32(np, "samsung,i2c-slave-addr", &pdata->slave_addr);
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
+ * 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,sysreg-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);
+ return;
+ }
+ regmap_update_bits(i2c->sysreg, EXYNOS5_SYS_I2C_CFG, BIT(id), 0);
}
#else
static void
@@ -1264,6 +1289,9 @@ 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_i2c_cfg);
+
return 0;
}
@@ -1272,6 +1300,9 @@ static int s3c24xx_i2c_resume_noirq(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, EXYNOS5_SYS_I2C_CFG, i2c->sys_i2c_cfg);
+
clk_prepare_enable(i2c->clk);
s3c24xx_i2c_init(i2c);
clk_disable_unprepare(i2c->clk);
--
1.7.9.5
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