From: Shawn Guo Date: Sun, 5 Aug 2012 06:01:26 +0000 (+0800) Subject: gpio/mxc: specify gpio base for device tree probe X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=7e6086d9e54a159a6257c02bb7fc5805c614aad2;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git gpio/mxc: specify gpio base for device tree probe Currently, unlike the non-DT probe where the gpio base is specified with pdev->id, the DT probe uses the base dynamically allocated by gpio core, which uses a completely different numbering scheme. This causes two issues to user space applications which access sysfs entry /sys/class/gpio/gpioN. * It breaks the compatibility with user space applications between non-DT and DT kernels. * It's not intuitive and sometimes hard for users to map the Linux gpio number to the actual hardware pin. Use alias to identify the gpio port/bank, and then the gpio base can be specified with port id to solve above issues. If alias is not defined in device tree, the base number dynamically allocated by gpio core will be used. Signed-off-by: Shawn Guo Tested-by: Uwe Kleine-König Signed-off-by: Linus Walleij --- diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c index 76e8cda9c06f..80f44bb64a87 100644 --- a/drivers/gpio/gpio-mxc.c +++ b/drivers/gpio/gpio-mxc.c @@ -465,7 +465,8 @@ static int __devinit mxc_gpio_probe(struct platform_device *pdev) goto out_iounmap; port->bgc.gc.to_irq = mxc_gpio_to_irq; - port->bgc.gc.base = pdev->id * 32; + port->bgc.gc.base = (pdev->id < 0) ? of_alias_get_id(np, "gpio") * 32 : + pdev->id * 32; err = gpiochip_add(&port->bgc.gc); if (err)