From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-lb0-f180.google.com ([209.85.217.180]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1U2bjZ-0002vI-6X for barebox@lists.infradead.org; Tue, 05 Feb 2013 06:10:22 +0000 Received: by mail-lb0-f180.google.com with SMTP id q12so7184307lbc.25 for ; Mon, 04 Feb 2013 22:10:18 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20130204083759.GB1906@pengutronix.de> References: <1359918977-1932-1-git-send-email-antonynpavlov@gmail.com> <20130203211352.GH18068@game.jcrosoft.org> <20130204083759.GB1906@pengutronix.de> Date: Tue, 5 Feb 2013 10:10:18 +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: Sascha Hauer Cc: barebox@lists.infradead.org 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? -- Best regards, Antony Pavlov _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox