[PATCH v3 2/2] i2c: s3c2410: Add device tree support
Thomas Abraham
thomas.abraham at linaro.org
Tue Sep 13 14:16:05 EST 2011
Add device tree probe support for Samsung's s3c2410 i2c driver.
Cc: Ben Dooks <ben-linux at fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham at linaro.org>
Acked-by: Grant Likely <grant.likely at secretlab.ca>
---
.../devicetree/bindings/i2c/samsung-i2c.txt | 39 +++++++
drivers/i2c/busses/i2c-s3c2410.c | 110 +++++++++++++++++++-
2 files changed, 145 insertions(+), 4 deletions(-)
create mode 100644 Documentation/devicetree/bindings/i2c/samsung-i2c.txt
diff --git a/Documentation/devicetree/bindings/i2c/samsung-i2c.txt b/Documentation/devicetree/bindings/i2c/samsung-i2c.txt
new file mode 100644
index 0000000..d04186d
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/samsung-i2c.txt
@@ -0,0 +1,39 @@
+* Samsung's I2C controller
+
+The Samsung's I2C controller is used to interface with I2C devices.
+
+Required properties:
+ - compatible: value should be either of the following.
+ (a) "samsung, s3c2410-i2c", for i2c compatible with s3c2410 i2c.
+ (b) "samsung, s3c2440-i2c", for i2c compatible with s3c2440 i2c.
+ - reg: physical base address of the controller and length of memory mapped
+ region.
+ - interrupts: interrupt number to the cpu.
+ - samsung,i2c-sda-delay: Delay (in ns) applied to data line (SDA) edges.
+ - gpios: The order of the gpios should be the following: <SDA, SCL>.
+ The gpio specifier depends on the gpio controller.
+
+Optional properties:
+ - samsung,i2c-slave-addr: Slave address in multi-master enviroment. If not
+ 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.
+
+Example:
+
+ i2c at 13870000 {
+ compatible = "samsung,s3c2440-i2c";
+ reg = <0x13870000 0x100>;
+ interrupts = <345>;
+ samsung,i2c-sda-delay = <100>;
+ samsung,i2c-max-bus-freq = <100000>;
+ gpios = <&gpd1 2 0 /* SDA */
+ &gpd1 3 0 /* SCL */>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ wm8994 at 1a {
+ compatible = "wlf,wm8994";
+ reg = <0x1a>;
+ };
+ };
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index 266dd83..aaeabf9 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -35,6 +35,8 @@
#include <linux/cpufreq.h>
#include <linux/slab.h>
#include <linux/io.h>
+#include <linux/of_i2c.h>
+#include <linux/of_gpio.h>
#include <asm/irq.h>
@@ -79,6 +81,7 @@ struct s3c24xx_i2c {
struct i2c_adapter adap;
struct s3c2410_platform_i2c *pdata;
+ int gpios[2];
#ifdef CONFIG_CPU_FREQ
struct notifier_block freq_transition;
#endif
@@ -96,6 +99,12 @@ static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c)
struct platform_device *pdev = to_platform_device(i2c->dev);
enum s3c24xx_i2c_type type;
+#ifdef CONFIG_OF
+ if (i2c->dev->of_node)
+ return of_device_is_compatible(i2c->dev->of_node,
+ "samsung,s3c2440-i2c");
+#endif
+
type = platform_get_device_id(pdev)->driver_data;
return type == TYPE_S3C2440;
}
@@ -742,6 +751,49 @@ static inline void s3c24xx_i2c_deregister_cpufreq(struct s3c24xx_i2c *i2c)
}
#endif
+#ifdef CONFIG_OF
+static int s3c24xx_i2c_parse_dt_gpio(struct s3c24xx_i2c *i2c)
+{
+ int idx, gpio, ret;
+
+ for (idx = 0; idx < 2; idx++) {
+ gpio = of_get_gpio(i2c->dev->of_node, idx);
+ if (!gpio_is_valid(gpio)) {
+ dev_err(i2c->dev, "invalid gpio[%d]: %d\n", idx, gpio);
+ goto free_gpio;
+ }
+
+ ret = gpio_request(gpio, "i2c-bus");
+ if (ret) {
+ dev_err(i2c->dev, "gpio [%d] request failed\n", gpio);
+ goto free_gpio;
+ }
+ }
+ return 0;
+
+free_gpio:
+ while (--idx >= 0)
+ gpio_free(i2c->gpios[idx]);
+ return -EINVAL;
+}
+
+static void s3c24xx_i2c_dt_gpio_free(struct s3c24xx_i2c *i2c)
+{
+ unsigned int idx;
+ for (idx = 0; idx < 2; idx++)
+ gpio_free(i2c->gpios[idx]);
+}
+#else
+static int s3c24xx_i2c_parse_dt_gpio(struct s3c24xx_i2c *i2c)
+{
+ return -EINVAL;
+}
+
+static void s3c24xx_i2c_dt_gpio_free(struct s3c24xx_i2c *i2c)
+{
+}
+#endif
+
/* s3c24xx_i2c_init
*
* initialise the controller, set the IO lines and frequency
@@ -761,6 +813,9 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
if (pdata->cfg_gpio)
pdata->cfg_gpio(to_platform_device(i2c->dev));
+ else
+ if (s3c24xx_i2c_parse_dt_gpio(i2c))
+ return -EINVAL;
/* write slave address */
@@ -786,6 +841,34 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
return 0;
}
+#ifdef CONFIG_OF
+/* s3c24xx_i2c_parse_dt
+ *
+ * Parse the device tree node and retreive the platform data.
+*/
+
+static void
+s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c)
+{
+ struct s3c2410_platform_i2c *pdata = i2c->pdata;
+
+ if (!np)
+ return;
+
+ pdata->bus_num = -1; /* i2c bus number is dynamically assigned */
+ of_property_read_u32(np, "samsung,i2c-sda-delay", &pdata->sda_delay);
+ 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);
+}
+#else
+static void
+s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c)
+{
+ return;
+}
+#endif
+
/* s3c24xx_i2c_probe
*
* called by the bus driver when a suitable device is found
@@ -798,10 +881,12 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
struct resource *res;
int ret;
- pdata = pdev->dev.platform_data;
- if (!pdata) {
- dev_err(&pdev->dev, "no platform data\n");
- return -EINVAL;
+ if (!pdev->dev.of_node) {
+ pdata = pdev->dev.platform_data;
+ if (!pdata) {
+ dev_err(&pdev->dev, "no platform data\n");
+ return -EINVAL;
+ }
}
i2c = kzalloc(sizeof(struct s3c24xx_i2c), GFP_KERNEL);
@@ -818,6 +903,8 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
if (pdata)
memcpy(i2c->pdata, pdata, sizeof(*pdata));
+ else
+ s3c24xx_i2c_parse_dt(pdev->dev.of_node, i2c);
strlcpy(i2c->adap.name, "s3c2410-i2c", sizeof(i2c->adap.name));
i2c->adap.owner = THIS_MODULE;
@@ -914,6 +1001,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
*/
i2c->adap.nr = i2c->pdata->bus_num;
+ i2c->adap.dev.of_node = pdev->dev.of_node;
ret = i2c_add_numbered_adapter(&i2c->adap);
if (ret < 0) {
@@ -921,6 +1009,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
goto err_cpufreq;
}
+ of_i2c_register_devices(&i2c->adap);
platform_set_drvdata(pdev, i2c);
dev_info(&pdev->dev, "%s: S3C I2C adapter\n", dev_name(&i2c->adap.dev));
@@ -969,6 +1058,7 @@ static int s3c24xx_i2c_remove(struct platform_device *pdev)
iounmap(i2c->regs);
release_resource(i2c->ioarea);
+ s3c24xx_i2c_dt_gpio_free(i2c);
kfree(i2c->ioarea);
kfree(i2c);
@@ -1022,6 +1112,17 @@ static struct platform_device_id s3c24xx_driver_ids[] = {
};
MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
+#ifdef CONFIG_OF
+static const struct of_device_id s3c24xx_i2c_match[] = {
+ { .compatible = "samsung,s3c2410-i2c" },
+ { .compatible = "samsung,s3c2440-i2c" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match);
+#else
+#define s3c24xx_i2c_match NULL
+#endif
+
static struct platform_driver s3c24xx_i2c_driver = {
.probe = s3c24xx_i2c_probe,
.remove = s3c24xx_i2c_remove,
@@ -1030,6 +1131,7 @@ static struct platform_driver s3c24xx_i2c_driver = {
.owner = THIS_MODULE,
.name = "s3c-i2c",
.pm = S3C24XX_DEV_PM_OPS,
+ .of_match_table = s3c24xx_i2c_match,
},
};
--
1.6.6.rc2
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