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path: root/drivers/i2c/busses/i2c-s3c2410.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-s3c2410.c')
-rw-r--r--drivers/i2c/busses/i2c-s3c2410.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index 65244774bfa3..09a6bace457e 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -35,6 +35,8 @@
#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>
@@ -87,6 +89,9 @@
/* 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,
@@ -123,6 +128,8 @@ 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[] = {
@@ -1071,6 +1078,7 @@ 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;
@@ -1080,6 +1088,21 @@ 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 nodes 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))
+ return;
+
+ regmap_update_bits(i2c->sysreg, EXYNOS5_SYS_I2C_CFG, BIT(id), 0);
}
#else
static void
@@ -1260,6 +1283,9 @@ 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;
}
@@ -1268,6 +1294,9 @@ 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);