From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-la0-x22c.google.com ([2a00:1450:4010:c03::22c]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1U2gIk-0005oe-Ur for barebox@lists.infradead.org; Tue, 05 Feb 2013 11:03:00 +0000 Received: by mail-la0-f44.google.com with SMTP id eb20so1719lab.17 for ; Tue, 05 Feb 2013 03:02:54 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20130205101958.GB19322@game.jcrosoft.org> 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> Date: Tue, 5 Feb 2013 15:02:54 +0400 Message-ID: From: Antony Pavlov 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: Jean-Christophe PLAGNIOL-VILLARD Cc: barebox@lists.infradead.org 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. -- Best regards, Antony Pavlov _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox