Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@xxxxxxxxxxxx>
Cc: linux-i2c@xxxxxxxxxxxxxxx
Cc: devicetree-discuss@xxxxxxxxxxxxxxxx
---
.../devicetree/bindings/gpio/gpio_i2c.txt | 33 ++++++++++++
drivers/i2c/busses/i2c-gpio.c | 55 +++++++++++++++++++-
2 files changed, 86 insertions(+), 2 deletions(-)
create mode 100644 Documentation/devicetree/bindings/gpio/gpio_i2c.txt
diff --git a/Documentation/devicetree/bindings/gpio/gpio_i2c.txt b/Documentation/devicetree/bindings/gpio/gpio_i2c.txt
new file mode 100644
index 0000000..15f288da
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio_i2c.txt
@@ -0,0 +1,33 @@
+Device-Tree bindings for i2c gpio driver
+
+Required properties:
+ - compatible = "gpio-i2c";
+ - gpios: sda and scl gpio
+
+
+Optional properties:
+ - gpio-i2c,sda_is_open_drain: sda as open drain
+ - gpio-i2c,scl_is_open_drain: scl as open drain
+ - gpio-i2c,scl_is_output_only: scl as output only
+ - udelay: half clock cycle time in us (may depend on each platform)
+ - timeout: timeout to get data
+
+
+Example nodes:
+
+i2c-gpio@0 {
+ compatible = "gpio-i2c";
+ gpios = <&pioA 23 0 /* sda */
+ &pioA 24 0 /* scl */
+ >;
+ gpio-i2c,sda_is_open_drain;
+ gpio-i2c,scl_is_open_drain;
+ udelay = <2>; /* ~100 kHz */
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ rv3029c2@56 {
+ compatible = "rv3029c2";
+ reg = <0x56>;
+ };
+};
diff --git a/drivers/i2c/busses/i2c-gpio.c b/drivers/i2c/busses/i2c-gpio.c
index a651779..6b5d794 100644
--- a/drivers/i2c/busses/i2c-gpio.c
+++ b/drivers/i2c/busses/i2c-gpio.c
@@ -14,6 +14,8 @@
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
+#include <linux/of_gpio.h>
+#include <linux/of_i2c.h>
#include <asm/gpio.h>
@@ -78,16 +80,51 @@ static int i2c_gpio_getscl(void *data)
return gpio_get_value(pdata->scl_pin);
}
+static int of_i2c_gpio_probe(struct device_node *np,
+ struct i2c_gpio_platform_data *pdata)
+{
+ u32 reg;
+
+ pdata->sda_pin = of_get_gpio(np, 0);
+ pdata->scl_pin = of_get_gpio(np, 1);
+
+ if (of_property_read_u32(np, "udelay", ®))
+ pdata->udelay = reg;
+
+ if (of_property_read_u32(np, "timeout", ®))
+ pdata->timeout = reg;
+
+ pdata->sda_is_open_drain =
+ !!of_get_property(np, "gpio-i2c,sda_is_open_drain", NULL);
+ pdata->scl_is_open_drain =
+ !!of_get_property(np, "gpio-i2c,scl_is_open_drain", NULL);
+ pdata->scl_is_output_only =
+ !!of_get_property(np, "gpio-i2c,scl_is_output_only", NULL);
+
+ return 0;
+}
+
static int __devinit i2c_gpio_probe(struct platform_device *pdev)
{
struct i2c_gpio_platform_data *pdata;
struct i2c_algo_bit_data *bit_data;
struct i2c_adapter *adap;
int ret;
+ int len = sizeof(struct i2c_gpio_platform_data);
- pdata = pdev->dev.platform_data;
+ pdata = kzalloc(len, GFP_KERNEL);
if (!pdata)
- return -ENXIO;
+ return -ENOMEM;
+
+ if (pdev->dev.of_node) {
+ of_i2c_gpio_probe(pdev->dev.of_node, pdata);
+ } else {
+ if (!pdev->dev.platform_data) {
+ ret = -ENXIO;
+ goto err_alloc_adap;
+ }
+ memcpy(pdata, pdev->dev.platform_data, len);
+ }
ret = -ENOMEM;
adap = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
@@ -143,6 +180,7 @@ static int __devinit i2c_gpio_probe(struct platform_device *pdev)
adap->algo_data = bit_data;
adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
adap->dev.parent = &pdev->dev;
+ adap->dev.of_node = pdev->dev.of_node;
/*
* If "dev->id" is negative we consider it as zero.
@@ -154,6 +192,8 @@ static int __devinit i2c_gpio_probe(struct platform_device *pdev)
if (ret)
goto err_add_bus;
+ of_i2c_register_devices(adap);
+
platform_set_drvdata(pdev, adap);
dev_info(&pdev->dev, "using pins %u (SDA) and %u (SCL%s)\n",
@@ -172,6 +212,7 @@ err_request_sda:
err_alloc_bit_data:
kfree(adap);
err_alloc_adap:
+ kfree(pdata);
return ret;
}
@@ -192,10 +233,20 @@ static int __devexit i2c_gpio_remove(struct platform_device *pdev)
return 0;
}
+#if defined(CONFIG_OF)
+static const struct of_device_id gpio_i2c_dt_ids[] = {
+ { .compatible = "gpio-i2c", },
+ { /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, gpio_i2c_dt_ids);
+#endif
+
static struct platform_driver i2c_gpio_driver = {
.driver = {
.name = "i2c-gpio",
.owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(gpio_i2c_dt_ids),
},
.probe = i2c_gpio_probe,
.remove = __devexit_p(i2c_gpio_remove),
--
1.7.7
--
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