Add device tree support for Samsung's s3c24xx i2c driver. It adds support for parsing platform data from device tree and initialize all the slave devices specified as child nodes.
Signed-off-by: Thomas Abraham <[email protected]> --- .../devicetree/bindings/i2c/samsung-i2c.txt | 43 ++++++++++ drivers/i2c/busses/i2c-s3c2410.c | 87 ++++++++++++++++---- 2 files changed, 115 insertions(+), 15 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..73191c3 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/samsung-i2c.txt @@ -0,0 +1,43 @@ +* 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-bus-number: Specifies the i2c bus number. + + - samsung,i2c-sda-delay: Delay (in ns) applied to data line (SDA) edges. + +Optional properties: + - samsung,i2c-slave-addr: Slave address in multi-master enviroment. If not + specified, default value is 0x10. + + - 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-bus-number = <1>; + samsung,i2c-slave-addr = <16>; + samsung,i2c-sda-delay = <100>; + samsung,i2c-max-bus-freq = <100000>; + #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 6c00c10..5a84a0b 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -35,6 +35,9 @@ #include <linux/cpufreq.h> #include <linux/slab.h> #include <linux/io.h> +#include <linux/of.h> +#include <linux/of_i2c.h> +#include <linux/of_device.h> #include <asm/irq.h> @@ -83,6 +86,33 @@ struct s3c24xx_i2c { #endif }; +#ifdef CONFIG_OF +static enum s3c24xx_i2c_type samsung_i2c_types[] = { + TYPE_S3C2410, + TYPE_S3C2440 +}; + +static const struct of_device_id s3c24xx_i2c_match[] = { + { .compatible = "samsung,s3c2410-i2c", .data = &samsung_i2c_types[0], }, + { .compatible = "samsung,s3c2440-i2c", .data = &samsung_i2c_types[1], }, + {}, +}; +MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match); + +static const struct +of_device_id *s3c24xx_i2c_get_of_device_id(struct platform_device *pdev) +{ + return of_match_device(s3c24xx_i2c_match, &pdev->dev); +} +#else +#define s3c24xx_i2c_match NULL +static const struct +of_device_id *s3c24xx_i2c_get_of_device_id(struct platform_device *pdev) +{ + return NULL; +} +#endif + /* default platform data removed, dev should always carry data. */ /* s3c24xx_i2c_is2440() @@ -93,9 +123,15 @@ struct s3c24xx_i2c { static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c) { struct platform_device *pdev = to_platform_device(i2c->dev); + const struct of_device_id *i2c_of_id; enum s3c24xx_i2c_type type; - type = platform_get_device_id(pdev)->driver_data; + i2c_of_id = s3c24xx_i2c_get_of_device_id(pdev); + if (platform_get_device_id(pdev)) + type = platform_get_device_id(pdev)->driver_data; + else + type = *(enum s3c24xx_i2c_type *)i2c_of_id->data; + return type == TYPE_S3C2440; } @@ -630,16 +666,21 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got) unsigned long clkin = clk_get_rate(i2c->clk); unsigned int divs, div1; unsigned long target_frequency; + unsigned int max_freq = 0; u32 iiccon; int freq; i2c->clkrate = clkin; clkin /= 1000; /* clkin now in KHz */ - dev_dbg(i2c->dev, "pdata desired frequency %lu\n", pdata->frequency); - - target_frequency = pdata->frequency ? pdata->frequency : 100000; + if (i2c->dev->of_node) + of_property_read_u32(i2c->dev->of_node, + "samsung,i2c-max-bus-freq", &max_freq); + else + max_freq = pdata->frequency; + dev_dbg(i2c->dev, "desired frequency %u\n", max_freq); + target_frequency = max_freq ? max_freq : 100000; target_frequency /= 1000; /* Target frequency now in KHz */ freq = s3c24xx_i2c_calcdivisor(clkin, target_frequency, &div1, &divs); @@ -663,19 +704,24 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got) writel(iiccon, i2c->regs + S3C2410_IICCON); if (s3c24xx_i2c_is2440(i2c)) { - unsigned long sda_delay; + unsigned int sda_delay = 0; - if (pdata->sda_delay) { - sda_delay = clkin * pdata->sda_delay; + if (i2c->dev->of_node) + of_property_read_u32(i2c->dev->of_node, + "samsung,i2c-sda-delay", &sda_delay); + else + sda_delay = pdata->sda_delay; + + if (sda_delay) { + sda_delay *= clkin; sda_delay = DIV_ROUND_UP(sda_delay, 1000000); sda_delay = DIV_ROUND_UP(sda_delay, 5); if (sda_delay > 3) sda_delay = 3; sda_delay |= S3C2410_IICLC_FILTER_ON; - } else - sda_delay = 0; + } - dev_dbg(i2c->dev, "IICLC=%08lx\n", sda_delay); + dev_dbg(i2c->dev, "IICLC=%08x\n", sda_delay); writel(sda_delay, i2c->regs + S3C2440_IICLC); } @@ -751,7 +797,7 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c) { unsigned long iicon = S3C2410_IICCON_IRQEN | S3C2410_IICCON_ACKEN; struct s3c2410_platform_i2c *pdata; - unsigned int freq; + unsigned int freq, slave_addr = 0x10; /* get the plafrom data */ @@ -763,10 +809,14 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c) pdata->cfg_gpio(to_platform_device(i2c->dev)); /* write slave address */ + if (i2c->dev->of_node) + of_property_read_u32(i2c->dev->of_node, + "samsung,i2c-slave-addr", &slave_addr); + else + slave_addr = pdata->slave_addr; + writeb(slave_addr, i2c->regs + S3C2410_IICADD); - writeb(pdata->slave_addr, i2c->regs + S3C2410_IICADD); - - dev_info(i2c->dev, "slave address 0x%02x\n", pdata->slave_addr); + dev_info(i2c->dev, "slave address 0x%02x\n", slave_addr); writel(iicon, i2c->regs + S3C2410_IICCON); @@ -904,7 +954,12 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) * being bus 0. */ - i2c->adap.nr = pdata->bus_num; + if (i2c->dev->of_node) + of_property_read_u32(i2c->dev->of_node, + "samsung,i2c-bus-number", &i2c->adap.nr); + else + i2c->adap.nr = pdata->bus_num; + i2c->adap.dev.of_node = pdev->dev.of_node; ret = i2c_add_numbered_adapter(&i2c->adap); if (ret < 0) { @@ -912,6 +967,7 @@ 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)); @@ -1021,6 +1077,7 @@ static struct platform_driver s3c24xx_i2c_driver = { .owner = THIS_MODULE, .name = "s3c-i2c", .pm = S3C24XX_DEV_PM_OPS, + .of_match_table = s3c24xx_i2c_match, }, }; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
