From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1U3AiY-0004Fe-Dh for barebox@lists.infradead.org; Wed, 06 Feb 2013 19:31:39 +0000 Date: Wed, 6 Feb 2013 20:31:35 +0100 From: Sascha Hauer Message-ID: <20130206193135.GA9183@pengutronix.de> References: <1359918977-1932-1-git-send-email-antonynpavlov@gmail.com> <20130203211352.GH18068@game.jcrosoft.org> <20130204083759.GB1906@pengutronix.de> <20130205092955.GT1906@pengutronix.de> <20130205101958.GB19322@game.jcrosoft.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: barebox-bounces@lists.infradead.org Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [RFC] gpiolib: import gpio_request_array() from linux 3.7 To: Antony Pavlov Cc: barebox@lists.infradead.org On Tue, Feb 05, 2013 at 03:02:54PM +0400, Antony Pavlov wrote: > On 5 February 2013 14:19, Jean-Christophe PLAGNIOL-VILLARD > wrote: > > On 10:29 Tue 05 Feb , Sascha Hauer wrote: > >> On Tue, Feb 05, 2013 at 10:10:18AM +0400, Antony Pavlov wrote: > >> > On 4 February 2013 12:37, Sascha Hauer wrote: > >> > > On Mon, Feb 04, 2013 at 01:22:39AM +0400, Antony Pavlov wrote: > >> > >> On 4 February 2013 01:13, Jean-Christophe PLAGNIOL-VILLARD > >> > >> wrote: > >> > >> > On 23:16 Sun 03 Feb , Antony Pavlov wrote: > >> > >> >> Also import related functions gpio_request_one() and > >> > >> >> gpio_free_array(). > >> > >> >> > >> > >> >> Signed-off-by: Antony Pavlov > >> > >> >> --- > >> > >> >> drivers/gpio/gpio.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++ > >> > >> >> include/gpio.h | 43 +++++++++++++++++++++++++++++++++ > >> > >> >> 2 files changed, 109 insertions(+) > >> > >> >> > >> > >> >> diff --git a/drivers/gpio/gpio.c b/drivers/gpio/gpio.c > >> > >> >> index d37f5a0..631168d 100644 > >> > >> >> --- a/drivers/gpio/gpio.c > >> > >> >> +++ b/drivers/gpio/gpio.c > >> > >> >> @@ -65,6 +65,72 @@ void gpio_free(unsigned gpio) > >> > >> >> free(gi->label); > >> > >> >> } > >> > >> >> > >> > >> >> +/** > >> > >> >> + * gpio_request_one - request a single GPIO with initial configuration > >> > >> >> + * @gpio: the GPIO number > >> > >> >> + * @flags: GPIO configuration as specified by GPIOF_* > >> > >> >> + * @label: a literal description string of this GPIO > >> > >> >> + */ > >> > >> >> +int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) > >> > >> >> +{ > >> > >> >> + int err; > >> > >> >> + > >> > >> >> + err = gpio_request(gpio, label); > >> > >> >> + if (err) > >> > >> >> + return err; > >> > >> >> + > >> > >> >> + if (flags & GPIOF_DIR_IN) > >> > >> >> + err = gpio_direction_input(gpio); > >> > >> >> + else > >> > >> >> + err = gpio_direction_output(gpio, > >> > >> >> + (flags & GPIOF_INIT_HIGH) ? 1 : 0); > >> > >> >> + > >> > >> >> + if (err) > >> > >> >> + goto free_gpio; > >> > >> >> + > >> > >> >> + return 0; > >> > >> >> + > >> > >> >> +free_gpio: > >> > >> >> + gpio_free(gpio); > >> > >> >> + return err; > >> > >> >> +} > >> > >> >> +EXPORT_SYMBOL(gpio_request_one); > >> > >> >> + > >> > >> >> +/** > >> > >> >> + * gpio_request_array - request multiple GPIOs in a single call > >> > >> >> + * @array: array of the 'struct gpio' > >> > >> >> + * @num: how many GPIOs in the array > >> > >> >> + */ > >> > >> >> +int gpio_request_array(const struct gpio *array, size_t num) > >> > >> >> +{ > >> > >> >> + int i, err; > >> > >> >> + > >> > >> >> + for (i = 0; i < num; i++, array++) { > >> > >> >> + err = gpio_request_one(array->gpio, array->flags, array->label); > >> > >> >> + if (err) > >> > >> >> + goto err_free; > >> > >> >> + } > >> > >> >> + return 0; > >> > >> >> + > >> > >> >> +err_free: > >> > >> >> + while (i--) > >> > >> >> + gpio_free((--array)->gpio); > >> > >> >> + return err; > >> > >> >> +} > >> > >> >> +EXPORT_SYMBOL(gpio_request_array); > >> > >> >> + > >> > >> >> +/** > >> > >> >> + * gpio_free_array - release multiple GPIOs in a single call > >> > >> >> + * @array: array of the 'struct gpio' > >> > >> >> + * @num: how many GPIOs in the array > >> > >> >> + */ > >> > >> >> +void gpio_free_array(const struct gpio *array, size_t num) > >> > >> >> +{ > >> > >> >> + while (num--) > >> > >> >> + gpio_free((array++)->gpio); > >> > >> >> +} > >> > >> >> +EXPORT_SYMBOL(gpio_free_array); > >> > >> >> + > >> > >> >> void gpio_set_value(unsigned gpio, int value) > >> > >> >> { > >> > >> >> struct gpio_info *gi = &gpio_desc[gpio]; > >> > >> >> diff --git a/include/gpio.h b/include/gpio.h > >> > >> >> index eedb980..37c151d 100644 > >> > >> >> --- a/include/gpio.h > >> > >> >> +++ b/include/gpio.h > >> > >> >> @@ -3,6 +3,29 @@ > >> > >> >> > >> > >> >> #include > >> > >> >> > >> > >> >> +/* make these flag values available regardless of GPIO kconfig options */ > >> > >> >> +#define GPIOF_DIR_OUT (0 << 0) > >> > >> >> +#define GPIOF_DIR_IN (1 << 0) > >> > >> >> + > >> > >> >> +#define GPIOF_INIT_LOW (0 << 1) > >> > >> >> +#define GPIOF_INIT_HIGH (1 << 1) > >> > >> >> + > >> > >> >> +#define GPIOF_IN (GPIOF_DIR_IN) > >> > >> >> +#define GPIOF_OUT_INIT_LOW (GPIOF_DIR_OUT | GPIOF_INIT_LOW) > >> > >> >> +#define GPIOF_OUT_INIT_HIGH (GPIOF_DIR_OUT | GPIOF_INIT_HIGH) > >> > >> >> + > >> > >> >> +/** > >> > >> >> + * struct gpio - a structure describing a GPIO with configuration > >> > >> >> + * @gpio: the GPIO number > >> > >> >> + * @flags: GPIO configuration as specified by GPIOF_* > >> > >> >> + * @label: a literal description string of this GPIO > >> > >> >> + */ > >> > >> >> +struct gpio { > >> > >> >> + unsigned gpio; > >> > >> >> + unsigned long flags; > >> > >> >> + const char *label; > >> > >> >> +}; > >> > >> >> + > >> > >> >> #ifndef CONFIG_GPIOLIB > >> > >> >> static inline int gpio_request(unsigned gpio, const char *label) > >> > >> >> { > >> > >> >> @@ -12,9 +35,29 @@ static inline int gpio_request(unsigned gpio, const char *label) > >> > >> >> static inline void gpio_free(unsigned gpio) > >> > >> >> { > >> > >> >> } > >> > >> >> + > >> > >> >> +static inline int gpio_request_one(unsigned gpio, > >> > >> >> + unsigned long flags, const char *label) > >> > >> >> +{ > >> > >> >> + return 0; > >> > >> >> +} > >> > >> >> + > >> > >> >> +static inline int gpio_request_array(const struct gpio *array, size_t num) > >> > >> >> +{ > >> > >> >> + return 0; > >> > >> >> +} > >> > >> > you can not do this > >> > >> > > >> > >> > as if we start to use this in generic driver where gpio_direction_input/output > >> > >> > work > >> > >> > > >> > >> > we will endup with no configuration > >> > >> > >> > >> But now in include/gpio.h we have this: > >> > >> > >> > >> static inline int gpio_request(unsigned gpio, const char *label) > >> > >> { > >> > >> return 0; > >> > >> } > >> > >> > >> > >> Can you explain the difference? > >> > > > >> > > gpio_request is not implemented without gpiolib, still you have to > >> > > configure the direction and value. > >> > > >> > Can we use this functions only if gpiolib is enabled? > >> > Can we skip the function's definiton in the non-gpio situation? > >> > >> Sounds fine. We should get rid of the !gpiolib drivers anyway, maybe > >> this adds some motivation. > > > > until every driver are swith to gpiolib NACK as if we switch any generic > > driver to this as leds, gpio-keys, i2c-gpio etc... we break board support > > siliently > > but leds, gpio-keys, i2c-gpio etc don't use > gpio_request_one()-related functions. > If we ristrict the usage of gpio_request_one()-related functions (use > it only in board code for gpiolib-enabled machines) > we can avoid mentioned problems. You should probably just provide a static inline wrapper for the !gpiolib case. It's sufficiently easy to do and avoids that someone who wants to use the functions in a driver has to fixup all other gpio drivers first. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox