Hi Ben, On 02/23/2011 09:12 AM, Ben Dooks wrote:
On Mon, Feb 14, 2011 at 10:30:10AM +0800, Thomas Chou wrote:From: Albert Herranz<albert_herranz@xxxxxxxx> 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<albert_herranz@xxxxxxxx>. Signed-off-by: Thomas Chou<thomas@xxxxxxxxxxxxx> CC: Albert Herranz<albert_herranz@xxxxxxxx> Acked-by: Haavard Skinnemoen<hskinnemoen@xxxxxxxxx> --- 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.
+/* 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;Would prefer to see different return code, most bus probe functions tend to drop these without signalling to the user as they assume the device was either never there or totally faulty.+ 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; + }see same as above.+ 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; +}might be valid here, however can we make this NULL if no support?
Thanks. How about return NULL if no support, and return pdata if support? - Thomas -- 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
