From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mout.gmx.net ([212.227.17.20]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jyUsA-0007or-EK for barebox@lists.infradead.org; Thu, 23 Jul 2020 06:38:31 +0000 Received: from [192.168.178.55] ([95.90.205.186]) by mail.gmx.com (mrgmx105 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MmDIu-1kgavc1JYW-00iG7k for ; Thu, 23 Jul 2020 08:25:24 +0200 References: <20200720064108.8426-1-o.rempel@pengutronix.de> From: Oleksij Rempel Message-ID: <5cf6b88f-db0b-bcce-b2f4-f9e14659b6e6@rempel-privat.de> Date: Thu, 23 Jul 2020 08:25:21 +0200 MIME-Version: 1.0 In-Reply-To: <20200720064108.8426-1-o.rempel@pengutronix.de> Content-Language: en-US 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" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH v1] gpiolib: add gpio_array_to_id helper to get ID out of GPIO array To: barebox@lists.infradead.org This version need some fixes, I'll send a new version soon Am 20.07.20 um 08:41 schrieb Oleksij Rempel: > Some boards provide a board version and/or ID coded by pull-up/down > resistors connected to the gpio pins (or pins which can be multiplexed > at some point as gpio). In this case every one implements own gpio id > reader function. > > To avoid it, provide the common helper function to extract a value out > of provided gpio array. > > Signed-off-by: Oleksij Rempel > --- > drivers/gpio/gpiolib.c | 28 ++++++++++++++++++++++++++++ > include/gpio.h | 5 +++++ > 2 files changed, 33 insertions(+) > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c > index 27674af54c..b3d7450ef2 100644 > --- a/drivers/gpio/gpiolib.c > +++ b/drivers/gpio/gpiolib.c > @@ -381,6 +381,34 @@ void gpio_free_array(const struct gpio *array, size_t num) > } > EXPORT_SYMBOL_GPL(gpio_free_array); > > +int gpio_array_to_id(const struct gpio *array, size_t num, u32 *val) > +{ > + u32 id = 0; > + int ret, i; > + > + if (num >= 32) > + return -EOVERFLOW; > + > + ret = gpio_request_array(array, num); > + if (ret) > + return ret; > + > + /* Wait untill logic level will be stable */ > + udelay(5); > + for (i = 0; i < num; i++) { > + ret = gpio_get_value(array[i].gpio); > + if (ret < 0) > + return ret; > + > + id |= ret << i; > + } > + > + *val = id; > + > + return 0; > +} > +EXPORT_SYMBOL(gpio_array_to_id); > + > static int gpiochip_find_base(int start, int ngpio) > { > int i; > diff --git a/include/gpio.h b/include/gpio.h > index 98c5b93ba2..81beb47309 100644 > --- a/include/gpio.h > +++ b/include/gpio.h > @@ -145,6 +145,10 @@ static inline void gpio_free_array(const struct gpio *array, size_t num) > /* GPIO can never have been requested */ > WARN_ON(1); > } > +static inline int gpio_array_to_id(const struct gpio *array, size_t num, u32 *val) > +{ > + return -EINVAL; > +} > #else > int gpio_request(unsigned gpio, const char *label); > int gpio_find_by_name(const char *name); > @@ -153,6 +157,7 @@ void gpio_free(unsigned gpio); > int gpio_request_one(unsigned gpio, unsigned long flags, const char *label); > int gpio_request_array(const struct gpio *array, size_t num); > void gpio_free_array(const struct gpio *array, size_t num); > +int gpio_array_to_id(const struct gpio *array, size_t num, u32 *val); > #endif > > struct gpio_chip; > -- Regards, Oleksij _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox