From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932644Ab2ERIFf (ORCPT ); Fri, 18 May 2012 04:05:35 -0400 Received: from antcom.de ([188.40.178.216]:59415 "EHLO chuck.antcom.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757069Ab2ERIFZ (ORCPT ); Fri, 18 May 2012 04:05:25 -0400 Message-ID: <4FB602C3.4060208@antcom.de> Date: Fri, 18 May 2012 10:05:23 +0200 From: Roland Stigge Organization: ANTCOM IT Research & Development User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:8.0) Gecko/20120216 Icedove/8.0 MIME-Version: 1.0 To: Grant Likely CC: linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] gpio: Adjust of_xlate API to support multiple GPIO chips References: <1337285060-31919-1-git-send-email-grant.likely@secretlab.ca> In-Reply-To: <1337285060-31919-1-git-send-email-grant.likely@secretlab.ca> X-Enigmail-Version: 1.3.4 OpenPGP: url=subkeys.pgp.net Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/17/2012 10:04 PM, Grant Likely wrote: > This patch changes the of_xlate API to make it possible for multiple > gpio_chips to refer to the same device tree node. This is useful for > banked GPIO controllers that use multiple gpio_chips for a single > device. With this change the core code will try calling of_xlate on > each gpio_chip that references the device_node and will return the > gpio number for the first one to return 'true'. > > Cc: Roland Stigge > Signed-off-by: Grant Likely Tested-by: Roland Stigge > --- > arch/arm/mach-imx/mach-mx35_3ds.c | 3 +- > drivers/gpio/gpiolib-of.c | 80 ++++++++++++++++++------------------- > drivers/gpio/gpiolib.c | 2 +- > include/asm-generic/gpio.h | 2 +- > include/linux/of_gpio.h | 1 - > 5 files changed, 41 insertions(+), 47 deletions(-) > > diff --git a/arch/arm/mach-imx/mach-mx35_3ds.c b/arch/arm/mach-imx/mach-mx35_3ds.c > index 6ae51c6..6a7cf91 100644 > --- a/arch/arm/mach-imx/mach-mx35_3ds.c > +++ b/arch/arm/mach-imx/mach-mx35_3ds.c > @@ -96,8 +96,7 @@ static struct i2c_board_info __initdata i2c_devices_3ds[] = { > > static int lcd_power_gpio = -ENXIO; > > -static int mc9s08dz60_gpiochip_match(struct gpio_chip *chip, > - const void *data) > +static int mc9s08dz60_gpiochip_match(struct gpio_chip *chip, void *data) > { > return !strcmp(chip->label, data); > } > diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c > index bf984b6..d18068a 100644 > --- a/drivers/gpio/gpiolib-of.c > +++ b/drivers/gpio/gpiolib-of.c > @@ -15,11 +15,39 @@ > #include > #include > #include > +#include > #include > #include > #include > #include > > +/* Private data structure for of_gpiochip_is_match */ > +struct gg_data { > + enum of_gpio_flags *flags; > + struct of_phandle_args gpiospec; > + > + int out_gpio; > +}; > + > +/* Private function for resolving node pointer to gpio_chip */ > +static int of_gpiochip_find_and_xlate(struct gpio_chip *gc, void *data) > +{ > + struct gg_data *gg_data = data; > + int ret; > + > + if ((gc->of_node != gg_data->gpiospec.np) || > + (gc->of_gpio_n_cells != gg_data->gpiospec.args_count) || > + (!gc->of_xlate)) > + return false; > + > + ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags); > + if (ret < 0) > + return false; > + > + gg_data->out_gpio = ret + gc->base; > + return true; > +} > + > /** > * of_get_named_gpio_flags() - Get a GPIO number and flags to use with GPIO API > * @np: device node to get GPIO from > @@ -34,46 +62,25 @@ > int of_get_named_gpio_flags(struct device_node *np, const char *propname, > int index, enum of_gpio_flags *flags) > { > + struct gg_data gg_data = { .flags = flags, .out_gpio = -ENODEV }; > int ret; > - struct gpio_chip *gc; > - struct of_phandle_args gpiospec; > + > + /* .of_xlate might decide to not fill in the flags, so clear it. */ > + if (flags) > + *flags = 0; > > ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index, > - &gpiospec); > + &gg_data.gpiospec); > if (ret) { > pr_debug("%s: can't parse gpios property\n", __func__); > - goto err0; > - } > - > - gc = of_node_to_gpiochip(gpiospec.np); > - if (!gc) { > - pr_debug("%s: gpio controller %s isn't registered\n", > - np->full_name, gpiospec.np->full_name); > - ret = -ENODEV; > - goto err1; > - } > - > - if (gpiospec.args_count != gc->of_gpio_n_cells) { > - pr_debug("%s: wrong #gpio-cells for %s\n", > - np->full_name, gpiospec.np->full_name); > - ret = -EINVAL; > - goto err1; > + return -EINVAL; > } > > - /* .xlate might decide to not fill in the flags, so clear it. */ > - if (flags) > - *flags = 0; > - > - ret = gc->of_xlate(gc, &gpiospec, flags); > - if (ret < 0) > - goto err1; > + gpiochip_find(&gg_data, of_gpiochip_find_and_xlate); > > - ret += gc->base; > -err1: > - of_node_put(gpiospec.np); > -err0: > + of_node_put(gg_data.gpiospec.np); > pr_debug("%s exited with status %d\n", __func__, ret); > - return ret; > + return gg_data.out_gpio; > } > EXPORT_SYMBOL(of_get_named_gpio_flags); > > @@ -227,14 +234,3 @@ void of_gpiochip_remove(struct gpio_chip *chip) > if (chip->of_node) > of_node_put(chip->of_node); > } > - > -/* Private function for resolving node pointer to gpio_chip */ > -static int of_gpiochip_is_match(struct gpio_chip *chip, const void *data) > -{ > - return chip->of_node == data; > -} > - > -struct gpio_chip *of_node_to_gpiochip(struct device_node *np) > -{ > - return gpiochip_find(np, of_gpiochip_is_match); > -} > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c > index 566d012..38353c0 100644 > --- a/drivers/gpio/gpiolib.c > +++ b/drivers/gpio/gpiolib.c > @@ -1156,7 +1156,7 @@ EXPORT_SYMBOL_GPL(gpiochip_remove); > */ > struct gpio_chip *gpiochip_find(const void *data, > int (*match)(struct gpio_chip *chip, > - const void *data)) > + void *data)) > { > struct gpio_chip *chip = NULL; > unsigned long flags; > diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h > index 5f52690..1cb3dd1 100644 > --- a/include/asm-generic/gpio.h > +++ b/include/asm-generic/gpio.h > @@ -144,7 +144,7 @@ extern int gpiochip_add(struct gpio_chip *chip); > extern int __must_check gpiochip_remove(struct gpio_chip *chip); > extern struct gpio_chip *gpiochip_find(const void *data, > int (*match)(struct gpio_chip *chip, > - const void *data)); > + void *data)); > > > /* Always use the library code for GPIO management calls, > diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h > index 81733d1..c454f57 100644 > --- a/include/linux/of_gpio.h > +++ b/include/linux/of_gpio.h > @@ -58,7 +58,6 @@ extern int of_mm_gpiochip_add(struct device_node *np, > > extern void of_gpiochip_add(struct gpio_chip *gc); > extern void of_gpiochip_remove(struct gpio_chip *gc); > -extern struct gpio_chip *of_node_to_gpiochip(struct device_node *np); > extern int of_gpio_simple_xlate(struct gpio_chip *gc, > const struct of_phandle_args *gpiospec, > u32 *flags);