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Message-ID: <51BAC3A1.80105@st.com>
Date: Fri, 14 Jun 2013 09:17:53 +0200
From: Patrice CHOTARD <patrice.chotard@...com>
To: Christian Ruppert <christian.ruppert@...lis.com>
Cc: Linus Walleij <linus.walleij@...aro.org>,
Stephen Warren <swarren@...dotorg.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
Grant Likely <grant.likely@...retlab.ca>,
Rob Herring <rob.herring@...xeda.com>,
Rob Landley <rob@...dley.net>,
Sascha Leuenberger <sascha.leuenberger@...lis.com>,
Pierrick Hascoet <pierrick.hascoet@...lis.com>,
"devicetree-discuss@...ts.ozlabs.org"
<devicetree-discuss@...ts.ozlabs.org>,
"linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
Alexandre Courbot <acourbot@...dia.com>
Subject: Re: [PATCH 1/2] Add pin list based GPIO ranges
On 06/13/2013 02:55 PM, Christian Ruppert wrote:
> Traditionally, GPIO ranges are based on consecutive ranges of both GPIO
> and pin numbers. This patch allows for GPIO ranges with arbitrary lists
> of pin numbers.
>
> Signed-off-by: Christian Ruppert <christian.ruppert@...lis.com>
> ---
> drivers/pinctrl/core.c | 59 ++++++++++++++++++++++++++++++++------
> include/linux/pinctrl/pinctrl.h | 4 ++-
> 2 files changed, 52 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
> index 5327f35..25bb17e 100644
> --- a/drivers/pinctrl/core.c
> +++ b/drivers/pinctrl/core.c
> @@ -280,6 +280,29 @@ static int pinctrl_register_pins(struct pinctrl_dev *pctldev,
> }
>
> /**
> + * gpio_to_pin() - GPIO range GPIO number to pin number translation
> + * @range: GPIO range used for the translation
> + * @gpio: gpio pin to translate to a pin number
> + *
> + * Finds the pin number for a given GPIO using the specified GPIO range
> + * as a base for translation. The distinction between linear GPIO ranges
> + * and pin list based GPIO ranges is managed correctly by this function.
> + *
> + * This function assumes the gpio is part of the specified GPIO range, use
> + * only after making sure this is the case (e.g. by calling it on the
> + * result of successful pinctrl_get_device_gpio_range calls)!
> + */
> +static inline int gpio_to_pin(struct pinctrl_gpio_range *range,
> + unsigned int gpio)
> +{
> + unsigned int offset = gpio - range->base;
> + if (range->pins)
> + return range->pins[offset];
> + else
> + return range->pin_base + offset;
> +}
> +
> +/**
> * pinctrl_match_gpio_range() - check if a certain GPIO pin is in range
> * @pctldev: pin controller device to check
> * @gpio: gpio pin to check taken from the global GPIO pin space
> @@ -444,8 +467,14 @@ pinctrl_find_gpio_range_from_pin(struct pinctrl_dev *pctldev,
> /* Loop over the ranges */
> list_for_each_entry(range, &pctldev->gpio_ranges, node) {
> /* Check if we're in the valid range */
> - if (pin >= range->pin_base &&
> - pin < range->pin_base + range->npins) {
> + if (range->pins) {
> + int a;
> + for (a = 0; a < range->npins; a++) {
> + if (range->pins[a] == pin)
> + return range;
> + }
> + } else if (pin >= range->pin_base &&
> + pin < range->pin_base + range->npins) {
> mutex_unlock(&pctldev->mutex);
> return range;
> }
> @@ -528,7 +557,7 @@ int pinctrl_request_gpio(unsigned gpio)
> }
>
> /* Convert to the pin controllers number space */
> - pin = gpio - range->base + range->pin_base;
> + pin = gpio_to_pin(range, gpio);
>
> ret = pinmux_request_gpio(pctldev, range, pin, gpio);
>
> @@ -562,7 +591,7 @@ void pinctrl_free_gpio(unsigned gpio)
> mutex_lock(&pctldev->mutex);
>
> /* Convert to the pin controllers number space */
> - pin = gpio - range->base + range->pin_base;
> + pin = gpio_to_pin(range, gpio);
>
> pinmux_free_gpio(pctldev, pin, range);
>
> @@ -589,7 +618,7 @@ static int pinctrl_gpio_direction(unsigned gpio, bool input)
> mutex_lock(&pctldev->mutex);
>
> /* Convert to the pin controllers number space */
> - pin = gpio - range->base + range->pin_base;
> + pin = gpio_to_pin(range, gpio);
> ret = pinmux_gpio_direction(pctldev, range, pin, input);
>
> mutex_unlock(&pctldev->mutex);
> @@ -1296,11 +1325,21 @@ static int pinctrl_gpioranges_show(struct seq_file *s, void *what)
>
> /* Loop over the ranges */
> list_for_each_entry(range, &pctldev->gpio_ranges, node) {
> - seq_printf(s, "%u: %s GPIOS [%u - %u] PINS [%u - %u]\n",
> - range->id, range->name,
> - range->base, (range->base + range->npins - 1),
> - range->pin_base,
> - (range->pin_base + range->npins - 1));
> + if (range->pins) {
> + int a;
> + seq_printf(s, "%u: %s GPIOS [%u - %u] PINS {",
> + range->id, range->name,
> + range->base, (range->base + range->npins - 1));
> + for (a = 0; a < range->npins - 1; a++)
> + seq_printf(s, "%u, ", range->pins[a]);
> + seq_printf(s, "%u}\n", range->pins[a]);
> + }
> + else
> + seq_printf(s, "%u: %s GPIOS [%u - %u] PINS [%u - %u]\n",
> + range->id, range->name,
> + range->base, (range->base + range->npins - 1),
> + range->pin_base,
> + (range->pin_base + range->npins - 1));
> }
>
> mutex_unlock(&pctldev->mutex);
> diff --git a/include/linux/pinctrl/pinctrl.h b/include/linux/pinctrl/pinctrl.h
> index 2c2a9e8..176a6c1 100644
> --- a/include/linux/pinctrl/pinctrl.h
> +++ b/include/linux/pinctrl/pinctrl.h
> @@ -49,7 +49,8 @@ struct pinctrl_pin_desc {
> * @name: a name for the chip in this range
> * @id: an ID number for the chip in this range
> * @base: base offset of the GPIO range
> - * @pin_base: base pin number of the GPIO range
> + * @pin_base: base pin number of the GPIO range if pins != NULL
Hi Christian,
It seems that your comment is not correct, it should be :
* @pin_base: base pin number of the GPIO range if pins == NULL
Patrice
> + * @pins: enumeration of pins in GPIO range or NULL
> * @npins: number of pins in the GPIO range, including the base number
> * @gc: an optional pointer to a gpio_chip
> */
> @@ -59,6 +60,7 @@ struct pinctrl_gpio_range {
> unsigned int id;
> unsigned int base;
> unsigned int pin_base;
> + unsigned const *pins;
> unsigned int npins;
> struct gpio_chip *gc;
> };
--
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