diff options
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/samsung-i2c.txt | 39 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-s3c2410.c | 110 |
2 files changed, 145 insertions, 4 deletions
diff --git a/Documentation/devicetree/bindings/i2c/samsung-i2c.txt b/Documentation/devicetree/bindings/i2c/samsung-i2c.txt new file mode 100644 index 000000000000..38832c712919 --- /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@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@1a { + compatible = "wlf,wm8994"; + reg = <0x1a>; + }; + }; diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c index 266dd83a3ec2..9c00ad1f50a2 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, }, }; 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