diff options
| -rw-r--r-- | Documentation/devicetree/bindings/gpio/gpio_i2c.txt | 32 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-gpio.c | 98 |
2 files changed, 108 insertions, 22 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio_i2c.txt b/Documentation/devicetree/bindings/gpio/gpio_i2c.txt new file mode 100644 index 000000000000..4f8ec947c6bd --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/gpio_i2c.txt @@ -0,0 +1,32 @@ +Device-Tree bindings for i2c gpio driver + +Required properties: + - compatible = "i2c-gpio"; + - gpios: sda and scl gpio + + +Optional properties: + - i2c-gpio,sda-open-drain: sda as open drain + - i2c-gpio,scl-open-drain: scl as open drain + - i2c-gpio,scl-output-only: scl as output only + - i2c-gpio,delay-us: delay between GPIO operations (may depend on each platform) + - i2c-gpio,timeout-ms: timeout to get data + +Example nodes: + +i2c@0 { + compatible = "i2c-gpio"; + gpios = <&pioA 23 0 /* sda */ + &pioA 24 0 /* scl */ + >; + i2c-gpio,sda-open-drain; + i2c-gpio,scl-open-drain; + i2c-gpio,delay-us = <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 a651779d9ff7..c0330a41db03 100644 --- a/drivers/i2c/busses/i2c-gpio.c +++ b/drivers/i2c/busses/i2c-gpio.c @@ -14,8 +14,15 @@ #include <linux/module.h> #include <linux/slab.h> #include <linux/platform_device.h> - -#include <asm/gpio.h> +#include <linux/gpio.h> +#include <linux/of_gpio.h> +#include <linux/of_i2c.h> + +struct i2c_gpio_private_data { + struct i2c_adapter adap; + struct i2c_algo_bit_data bit_data; + struct i2c_gpio_platform_data pdata; +}; /* Toggle SDA by changing the direction of the pin */ static void i2c_gpio_setsda_dir(void *data, int state) @@ -78,24 +85,62 @@ static int i2c_gpio_getscl(void *data) return gpio_get_value(pdata->scl_pin); } +static int __devinit of_i2c_gpio_probe(struct device_node *np, + struct i2c_gpio_platform_data *pdata) +{ + u32 reg; + + if (of_gpio_count(np) < 2) + return -ENODEV; + + pdata->sda_pin = of_get_gpio(np, 0); + pdata->scl_pin = of_get_gpio(np, 1); + + if (!gpio_is_valid(pdata->sda_pin) || !gpio_is_valid(pdata->scl_pin)) { + pr_err("%s: invalid GPIO pins, sda=%d/scl=%d\n", + np->full_name, pdata->sda_pin, pdata->scl_pin); + return -ENODEV; + } + + of_property_read_u32(np, "i2c-gpio,delay-us", &pdata->udelay); + + if (!of_property_read_u32(np, "i2c-gpio,timeout-ms", ®)) + pdata->timeout = msecs_to_jiffies(reg); + + pdata->sda_is_open_drain = + of_property_read_bool(np, "i2c-gpio,sda-open-drain"); + pdata->scl_is_open_drain = + of_property_read_bool(np, "i2c-gpio,scl-open-drain"); + pdata->scl_is_output_only = + of_property_read_bool(np, "i2c-gpio,scl-output-only"); + + return 0; +} + static int __devinit i2c_gpio_probe(struct platform_device *pdev) { + struct i2c_gpio_private_data *priv; struct i2c_gpio_platform_data *pdata; struct i2c_algo_bit_data *bit_data; struct i2c_adapter *adap; int ret; - pdata = pdev->dev.platform_data; - if (!pdata) - return -ENXIO; - - ret = -ENOMEM; - adap = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL); - if (!adap) - goto err_alloc_adap; - bit_data = kzalloc(sizeof(struct i2c_algo_bit_data), GFP_KERNEL); - if (!bit_data) - goto err_alloc_bit_data; + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + adap = &priv->adap; + bit_data = &priv->bit_data; + pdata = &priv->pdata; + + if (pdev->dev.of_node) { + ret = of_i2c_gpio_probe(pdev->dev.of_node, pdata); + if (ret) + return ret; + } else { + if (!pdev->dev.platform_data) + return -ENXIO; + memcpy(pdata, pdev->dev.platform_data, sizeof(*pdata)); + } ret = gpio_request(pdata->sda_pin, "sda"); if (ret) @@ -143,6 +188,7 @@ 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. @@ -154,7 +200,9 @@ static int __devinit i2c_gpio_probe(struct platform_device *pdev) if (ret) goto err_add_bus; - platform_set_drvdata(pdev, adap); + of_i2c_register_devices(adap); + + platform_set_drvdata(pdev, priv); dev_info(&pdev->dev, "using pins %u (SDA) and %u (SCL%s)\n", pdata->sda_pin, pdata->scl_pin, @@ -168,34 +216,40 @@ err_add_bus: err_request_scl: gpio_free(pdata->sda_pin); err_request_sda: - kfree(bit_data); -err_alloc_bit_data: - kfree(adap); -err_alloc_adap: return ret; } static int __devexit i2c_gpio_remove(struct platform_device *pdev) { + struct i2c_gpio_private_data *priv; struct i2c_gpio_platform_data *pdata; struct i2c_adapter *adap; - adap = platform_get_drvdata(pdev); - pdata = pdev->dev.platform_data; + priv = platform_get_drvdata(pdev); + adap = &priv->adap; + pdata = &priv->pdata; i2c_del_adapter(adap); gpio_free(pdata->scl_pin); gpio_free(pdata->sda_pin); - kfree(adap->algo_data); - kfree(adap); return 0; } +#if defined(CONFIG_OF) +static const struct of_device_id i2c_gpio_dt_ids[] = { + { .compatible = "i2c-gpio", }, + { /* sentinel */ } +}; + +MODULE_DEVICE_TABLE(of, i2c_gpio_dt_ids); +#endif + static struct platform_driver i2c_gpio_driver = { .driver = { .name = "i2c-gpio", .owner = THIS_MODULE, + .of_match_table = of_match_ptr(i2c_gpio_dt_ids), }, .probe = i2c_gpio_probe, .remove = __devexit_p(i2c_gpio_remove), |