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 <thomas.abraham@xxxxxxxxxx>
---
.../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 majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
