On Mon, Feb 14, 2011 at 10:30:10AM +0800, Thomas Chou wrote: > From: Albert Herranz <[email protected]> > > This patch adds devicetree support to i2c-gpio driver. The allocation > of local data is integrated to a private structure, and use devm_* > helper for easy cleanup. > > It is base on an earlier patch for gc-linux from > Albert Herranz <[email protected]>. > > Signed-off-by: Thomas Chou <[email protected]> > CC: Albert Herranz <[email protected]> > Acked-by: Haavard Skinnemoen <[email protected]>
One minor nitpick below, but I'd be fine with cleaning that up via a followup patch. This one looks correct to me. Acked-by: Grant Likely <[email protected]> Ben, this one depends on a patch in my devicetree/next tree. How do you want to handle it? g. > --- > for v2.6.39 > v2 move of nodes probing to a hook, which will be optimized out > when devicetree is not used. > use linux/gpio.h. > move binding doc to i2c/i2c-gpio.txt. > v3 use speed-hz instead of udelay in dts binding. > condition the devicetree probe. > v4 simplify private allocation. > v5 condition module device table export for of. > > Documentation/devicetree/bindings/i2c/i2c-gpio.txt | 40 +++++++ > drivers/i2c/busses/i2c-gpio.c | 113 > ++++++++++++++++---- > 2 files changed, 133 insertions(+), 20 deletions(-) > create mode 100644 Documentation/devicetree/bindings/i2c/i2c-gpio.txt > > diff --git a/Documentation/devicetree/bindings/i2c/i2c-gpio.txt > b/Documentation/devicetree/bindings/i2c/i2c-gpio.txt > new file mode 100644 > index 0000000..38ef4f2 > --- /dev/null > +++ b/Documentation/devicetree/bindings/i2c/i2c-gpio.txt > @@ -0,0 +1,40 @@ > +GPIO-based I2C > + > +Required properties: > +- compatible : should be "i2c-gpio". > +- gpios : should specify GPIOs used for SDA and SCL lines, in that order. > +Optional properties: > +- sda-is-open-drain : present if SDA gpio is open-drain. > +- scl-is-open-drain : present if SCL gpio is open-drain. > +- scl-is-output-only : present if the output driver for SCL cannot be > + turned off. this will prevent clock stretching from working. > +- speed-hz : SCL frequency. > +- timeout : clock stretching timeout in milliseconds. > + > +Example: > + > +gpio0: starlet-gpio@0d8000c0 { > + compatible = "nintendo,starlet-gpio"; > + reg = <0d8000c0 4>; > + gpio-controller; > + #gpio-cells = <2>; > +}; > + > +i2c-video { > + #address-cells = <1>; > + #size-cells = <0>; > + compatible = "i2c-gpio"; > + > + gpios = <&gpio0 10 0 /* SDA line */ > + &gpio0 11 0 /* SCL line */ > + >; > + sda-is-open-drain; > + scl-is-open-drain; > + scl-is-output-only; > + speed-hz = <250000>; > + > + audio-video-encoder { > + compatible = "nintendo,wii-ave-rvl"; > + reg = <70>; > + }; > +}; > diff --git a/drivers/i2c/busses/i2c-gpio.c b/drivers/i2c/busses/i2c-gpio.c > index d9aa9a6..6cc5f15 100644 > --- a/drivers/i2c/busses/i2c-gpio.c > +++ b/drivers/i2c/busses/i2c-gpio.c > @@ -14,8 +14,14 @@ > #include <linux/module.h> > #include <linux/slab.h> > #include <linux/platform_device.h> > +#include <linux/gpio.h> > +#include <linux/of_i2c.h> > > -#include <asm/gpio.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 +84,80 @@ static int i2c_gpio_getscl(void *data) > return gpio_get_value(pdata->scl_pin); > } > > +#ifdef CONFIG_OF > +#include <linux/of_gpio.h> Instead of putting the include here, please add #ifdef CONFIG_OF protection around the contents of linux/of_gpio.h itself. I fully support that change so that includes can remain at the top where they belong. > + > +/* Check if devicetree nodes exist and build platform data */ > +static int i2c_gpio_of_probe(struct platform_device *pdev, > + struct i2c_gpio_platform_data *pdata) > +{ > + struct device_node *np = pdev->dev.of_node; > + const __be32 *prop; > + int sda_pin, scl_pin; > + int len; > + > + if (!np || of_gpio_count(np) < 2) > + return -ENXIO; > + > + sda_pin = of_get_gpio_flags(np, 0, NULL); > + scl_pin = of_get_gpio_flags(np, 1, NULL); > + if (sda_pin < 0 || scl_pin < 0) { > + pr_err("%s: invalid GPIO pins, sda=%d/scl=%d\n", > + np->full_name, sda_pin, scl_pin); > + return -ENXIO; > + } > + > + pdata->sda_pin = sda_pin; > + pdata->scl_pin = scl_pin; > + prop = of_get_property(np, "sda-is-open-drain", NULL); > + if (prop) > + pdata->sda_is_open_drain = 1; > + prop = of_get_property(np, "scl-is-open-drain", NULL); > + if (prop) > + pdata->scl_is_open_drain = 1; > + prop = of_get_property(np, "scl-is-output-only", NULL); > + if (prop) > + pdata->scl_is_output_only = 1; > + prop = of_get_property(np, "speed-hz", &len); > + if (prop && len >= sizeof(__be32)) > + pdata->udelay = DIV_ROUND_UP(1000000, be32_to_cpup(prop) * 2); > + prop = of_get_property(np, "timeout", &len); > + if (prop && len >= sizeof(__be32)) > + pdata->timeout = msecs_to_jiffies(be32_to_cpup(prop)); > + > + return 0; > +} > +#else > +static int i2c_gpio_of_probe(struct platform_device *pdev, > + struct i2c_gpio_platform_data *pdata) > +{ > + return -ENXIO; > +} > +#endif > + > 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; > + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + adap = &priv->adap; > + bit_data = &priv->bit_data; > + pdata = &priv->pdata; > > - 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; > + if (pdev->dev.platform_data) { > + *pdata = *(struct i2c_gpio_platform_data *) > + pdev->dev.platform_data; > + } else { > + ret = i2c_gpio_of_probe(pdev, pdata); > + if (ret) > + return ret; > + } > > ret = gpio_request(pdata->sda_pin, "sda"); > if (ret) > @@ -143,6 +205,7 @@ 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. > @@ -154,13 +217,16 @@ static int __devinit i2c_gpio_probe(struct > platform_device *pdev) > if (ret) > goto err_add_bus; > > - platform_set_drvdata(pdev, 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, > pdata->scl_is_output_only > ? ", no clock stretching" : ""); > > + /* Now register all the child nodes */ > + of_i2c_register_devices(adap); > + > return 0; > > err_add_bus: > @@ -168,34 +234,41 @@ 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; > } > > +#ifdef CONFIG_OF > +static const struct of_device_id i2c_gpio_match[] = { > + { .compatible = "i2c-gpio", }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, i2c_gpio_match); > +#else /* CONFIG_OF */ > +#define i2c_gpio_match NULL > +#endif /* CONFIG_OF */ > + > static struct platform_driver i2c_gpio_driver = { > .driver = { > .name = "i2c-gpio", > .owner = THIS_MODULE, > + .of_match_table = i2c_gpio_match, > }, > .probe = i2c_gpio_probe, > .remove = __devexit_p(i2c_gpio_remove), > -- > 1.7.4 > _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
