On 19:38 Mon 06 Feb , Karol Lewandowski wrote: > On 05.02.2012 11:38, Jean-Christophe PLAGNIOL-VILLARD wrote: > > Hi! > > >+Device-Tree bindings for i2c gpio driver > >+ > >+Required properties: > >+ - compatible = "gpio-i2c"; > > Driver name is "i2c-gpio" in file i2c-gpio.c. Previous version of > patch adding DT-support (prepared by Thomas Chou[1]) used i2c-gpio - > could we stick to that name? > > [1] https://lkml.org/lkml/2011/2/23/584 > > >+ - 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 > > Most of DT-properties I've seen used hyphen, not underscore. Could > we stick to that convention? > > (Nitpick: I think that "is" in property names is redundant too.) > > >+ - udelay: half clock cycle time in us (may depend on each platform) > > Could we use "clock-frequency" as Grant have suggested during review > of previous patch to i2c-gpio? as exaplained no as for gpio the delay is platform dependent > > https://lkml.org/lkml/2011/2/24/220 > > >+ - 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; > >+ > > if (of_gpio_count(np) < 2) > return -EINVAL; ok > > >+ pdata->sda_pin = of_get_gpio(np, 0); > >+ pdata->scl_pin = of_get_gpio(np, 1); > > if (pdata->sda_pin < 0 || pdata->scl_pin < 0) > return -EINVAL; > > >+ > >+ 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); > > Could you also take into account Grant's comment about > private/platform data? > > https://lkml.org/lkml/2011/2/3/221 > > > if (!pdata) > >- return -ENXIO; > >+ return -ENOMEM; > >+ > >+ if (pdev->dev.of_node) { > >+ of_i2c_gpio_probe(pdev->dev.of_node, pdata); > > Above might fail if configuration is corrupted. > > >+ } 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", }, > > There seem to be no good reason to make DT-compatible string > different from driver's name that's already in use: > > > static struct platform_driver i2c_gpio_driver = { > > .driver = { > > .name = "i2c-gpio", > > Regards, > -- > Karol Lewandowski | Samsung Poland R&D Center | Linux/Platform -- 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
