diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt index 4e16ba4feab0f309071ffb75e866e1a8980b7700..a33628759d36e10a0c4b2c181458311134561eaa 100644 --- a/Documentation/devicetree/bindings/gpio/gpio.txt +++ b/Documentation/devicetree/bindings/gpio/gpio.txt @@ -75,4 +75,40 @@ Example of two SOC GPIO banks defined as gpio-controller nodes: gpio-controller; }; +2.1) gpio-controller and pinctrl subsystem +------------------------------------------ +gpio-controller on a SOC might be tightly coupled with the pinctrl +subsystem, in the sense that the pins can be used by other functions +together with optional gpio feature. + +While the pin allocation is totally managed by the pin ctrl subsystem, +gpio (under gpiolib) is still maintained by gpio drivers. It may happen +that different pin ranges in a SoC is managed by different gpio drivers. + +This makes it logical to let gpio drivers announce their pin ranges to +the pin ctrl subsystem and call 'pinctrl_request_gpio' in order to +request the corresponding pin before any gpio usage. + +For this, the gpio controller can use a pinctrl phandle and pins to +announce the pinrange to the pin ctrl subsystem. For example, + + qe_pio_e: gpio-controller@1460 { + #gpio-cells = <2>; + compatible = "fsl,qe-pario-bank-e", "fsl,qe-pario-bank"; + reg = <0x1460 0x18>; + gpio-controller; + gpio-ranges = <&pinctrl1 20 10>, <&pinctrl2 50 20>; + + } + +where, + &pinctrl1 and &pinctrl2 is the phandle to the pinctrl DT node. + + Next values specify the base pin and number of pins for the range + handled by 'qe_pio_e' gpio. In the given example from base pin 20 to + pin 29 under pinctrl1 and pin 50 to pin 69 under pinctrl2 is handled + by this gpio controller. + +The pinctrl node must have "#gpio-range-cells" property to show number of +arguments to pass with phandle from gpio controllers node. diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt index e08a883de36e316715bcdacebf9670f952c0de02..77a1d11af723282625dd3c3f326a5b6576fb437c 100644 --- a/Documentation/gpio.txt +++ b/Documentation/gpio.txt @@ -439,6 +439,48 @@ slower clock delays the rising edge of SCK, and the I2C master adjusts its signaling rate accordingly. +GPIO controllers and the pinctrl subsystem +------------------------------------------ + +A GPIO controller on a SOC might be tightly coupled with the pinctrl +subsystem, in the sense that the pins can be used by other functions +together with an optional gpio feature. We have already covered the +case where e.g. a GPIO controller need to reserve a pin or set the +direction of a pin by calling any of: + +pinctrl_request_gpio() +pinctrl_free_gpio() +pinctrl_gpio_direction_input() +pinctrl_gpio_direction_output() + +But how does the pin control subsystem cross-correlate the GPIO +numbers (which are a global business) to a certain pin on a certain +pin controller? + +This is done by registering "ranges" of pins, which are essentially +cross-reference tables. These are described in +Documentation/pinctrl.txt + +While the pin allocation is totally managed by the pinctrl subsystem, +gpio (under gpiolib) is still maintained by gpio drivers. It may happen +that different pin ranges in a SoC is managed by different gpio drivers. + +This makes it logical to let gpio drivers announce their pin ranges to +the pin ctrl subsystem before it will call 'pinctrl_request_gpio' in order +to request the corresponding pin to be prepared by the pinctrl subsystem +before any gpio usage. + +For this, the gpio controller can register its pin range with pinctrl +subsystem. There are two ways of doing it currently: with or without DT. + +For with DT support refer to Documentation/devicetree/bindings/gpio/gpio.txt. + +For non-DT support, user can call gpiochip_add_pin_range() with appropriate +parameters to register a range of gpio pins with a pinctrl driver. For this +exact name string of pinctrl device has to be passed as one of the +argument to this routine. + + What do these conventions omit? =============================== One of the biggest things these conventions omit is pin multiplexing, since diff --git a/Documentation/pinctrl.txt b/Documentation/pinctrl.txt index a1cd2f9428d715d9afb14060f2cb61b1923362e4..da40efbef6ec5599406a1e086f7b11aaaa06e018 100644 --- a/Documentation/pinctrl.txt +++ b/Documentation/pinctrl.txt @@ -364,6 +364,9 @@ will get an pin number into its handled number range. Further it is also passed the range ID value, so that the pin controller knows which range it should deal with. +Calling pinctrl_add_gpio_range from pinctrl driver is DEPRECATED. Please see +section 2.1 of Documentation/devicetree/bindings/gpio/gpio.txt on how to bind +pinctrl and gpio drivers. PINMUX interfaces ================= diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index f1a45997aea8c3255aa7ecb697c72abe0beaf6d0..a5b90c8e984421e97049626f3b6da3cfe85d74f9 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -19,6 +19,7 @@ #include #include #include +#include #include /* Private data structure for of_gpiochip_find_and_xlate */ @@ -216,6 +217,58 @@ int of_mm_gpiochip_add(struct device_node *np, } EXPORT_SYMBOL(of_mm_gpiochip_add); +#ifdef CONFIG_PINCTRL +void of_gpiochip_add_pin_range(struct gpio_chip *chip) +{ + struct device_node *np = chip->of_node; + struct gpio_pin_range *pin_range; + struct of_phandle_args pinspec; + int index = 0, ret; + + if (!np) + return; + + do { + ret = of_parse_phandle_with_args(np, "gpio-ranges", + "#gpio-range-cells", index, &pinspec); + if (ret) + break; + + pin_range = devm_kzalloc(chip->dev, sizeof(*pin_range), + GFP_KERNEL); + if (!pin_range) { + pr_err("%s: GPIO chip: failed to allocate pin ranges\n", + chip->label); + break; + } + + pin_range->range.name = chip->label; + pin_range->range.base = chip->base; + pin_range->range.pin_base = pinspec.args[0]; + pin_range->range.npins = pinspec.args[1]; + pin_range->pctldev = of_pinctrl_add_gpio_range(pinspec.np, + &pin_range->range); + + list_add_tail(&pin_range->node, &chip->pin_ranges); + + } while (index++); +} + +void of_gpiochip_remove_pin_range(struct gpio_chip *chip) +{ + struct gpio_pin_range *pin_range, *tmp; + + list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) { + list_del(&pin_range->node); + pinctrl_remove_gpio_range(pin_range->pctldev, + &pin_range->range); + } +} +#else +void of_gpiochip_add_pin_range(struct gpio_chip *chip) {} +void of_gpiochip_remove_pin_range(struct gpio_chip *chip) {} +#endif + void of_gpiochip_add(struct gpio_chip *chip) { if ((!chip->of_node) && (chip->dev)) @@ -229,11 +282,14 @@ void of_gpiochip_add(struct gpio_chip *chip) chip->of_xlate = of_gpio_simple_xlate; } + of_gpiochip_add_pin_range(chip); of_node_get(chip->of_node); } void of_gpiochip_remove(struct gpio_chip *chip) { + of_gpiochip_remove_pin_range(chip); + if (chip->of_node) of_node_put(chip->of_node); } diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 1c8d9e3380e17276e17e8f009659954e58d05bd1..f0b07bbfcc9a74cfaeed9ddd652c944904c5f96b 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1083,6 +1083,10 @@ int gpiochip_add(struct gpio_chip *chip) } } +#ifdef CONFIG_PINCTRL + INIT_LIST_HEAD(&chip->pin_ranges); +#endif + of_gpiochip_add(chip); unlock: @@ -1180,6 +1184,45 @@ struct gpio_chip *gpiochip_find(void *data, } EXPORT_SYMBOL_GPL(gpiochip_find); +#ifdef CONFIG_PINCTRL +void gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, + unsigned int pin_base, unsigned int npins) +{ + struct gpio_pin_range *pin_range; + + pin_range = devm_kzalloc(chip->dev, sizeof(*pin_range), GFP_KERNEL); + if (!pin_range) { + pr_err("%s: GPIO chip: failed to allocate pin ranges\n", + chip->label); + return; + } + + pin_range->range.name = chip->label; + pin_range->range.base = chip->base; + pin_range->range.pin_base = pin_base; + pin_range->range.npins = npins; + pin_range->pctldev = find_pinctrl_and_add_gpio_range(pinctl_name, + &pin_range->range); + + list_add_tail(&pin_range->node, &chip->pin_ranges); +} + +void gpiochip_remove_pin_ranges(struct gpio_chip *chip) +{ + struct gpio_pin_range *pin_range, *tmp; + + list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) { + list_del(&pin_range->node); + pinctrl_remove_gpio_range(pin_range->pctldev, + &pin_range->range); + } +} +#else +void gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, + unsigned int pin_base, unsigned int npins) {} +void gpiochip_remove_pin_ranges(struct gpio_chip *chip) {} +#endif + /* These "optional" allocation calls help prevent drivers from stomping * on each other, and help provide better diagnostics in debugfs. * They're called even less than the "set direction" calls. diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c index b1086dcde15dd6d49b9d5cc3153e096164bcffbd..71db586b2afdcdaed07039e7511a817370535b2e 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -345,6 +345,19 @@ void pinctrl_add_gpio_ranges(struct pinctrl_dev *pctldev, } EXPORT_SYMBOL_GPL(pinctrl_add_gpio_ranges); +struct pinctrl_dev *find_pinctrl_and_add_gpio_range(const char *devname, + struct pinctrl_gpio_range *range) +{ + struct pinctrl_dev *pctldev = get_pinctrl_dev_from_devname(devname); + + if (!pctldev) + return NULL; + + pinctrl_add_gpio_range(pctldev, range); + return pctldev; +} +EXPORT_SYMBOL_GPL(find_pinctrl_and_add_gpio_range); + /** * pinctrl_remove_gpio_range() - remove a range of GPIOs fro a pin controller * @pctldev: pin controller device to remove the range from diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c index fcb1de45473cd2f7f6df93cbe28542b774f59ab3..6728ec71cb6536b25e92c04e2b3237164fa0ec32 100644 --- a/drivers/pinctrl/devicetree.c +++ b/drivers/pinctrl/devicetree.c @@ -106,6 +106,19 @@ static struct pinctrl_dev *find_pinctrl_by_of_node(struct device_node *np) return NULL; } +struct pinctrl_dev *of_pinctrl_add_gpio_range(struct device_node *np, + struct pinctrl_gpio_range *range) +{ + struct pinctrl_dev *pctldev; + + pctldev = find_pinctrl_by_of_node(np); + if (!pctldev) + return NULL; + + pinctrl_add_gpio_range(pctldev, range); + return pctldev; +} + static int dt_to_map_one_config(struct pinctrl *p, const char *statename, struct device_node *np_config) { diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index a9432fc6b8ba7ade0b50d85c2582e81998c301fe..92e5c432421cd34fa68cb51823bb2b485a06fb1a 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -5,6 +5,7 @@ #include #include #include +#include #ifdef CONFIG_GPIOLIB @@ -47,6 +48,21 @@ struct seq_file; struct module; struct device_node; +#ifdef CONFIG_PINCTRL +/** + * struct gpio_pin_range - pin range controlled by a gpio chip + * @head: list for maintaining set of pin ranges, used internally + * @pctldev: pinctrl device which handles corresponding pins + * @range: actual range of pins controlled by a gpio controller + */ + +struct gpio_pin_range { + struct list_head node; + struct pinctrl_dev *pctldev; + struct pinctrl_gpio_range range; +}; +#endif + /** * struct gpio_chip - abstract a GPIO controller * @label: for diagnostics @@ -134,6 +150,15 @@ struct gpio_chip { int (*of_xlate)(struct gpio_chip *gc, const struct of_phandle_args *gpiospec, u32 *flags); #endif +#ifdef CONFIG_PINCTRL + /* + * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally + * describe the actual pin range which they serve in an SoC. This + * information would be used by pinctrl subsystem to configure + * corresponding pins for gpio usage. + */ + struct list_head pin_ranges; +#endif }; extern const char *gpiochip_is_requested(struct gpio_chip *chip, diff --git a/include/linux/gpio.h b/include/linux/gpio.h index 2e31e8b3a190bb652bb597104139d2f2b440d347..a28445992b7fcb44b145e8dc325623be9f5d1d22 100644 --- a/include/linux/gpio.h +++ b/include/linux/gpio.h @@ -231,6 +231,9 @@ static inline int irq_to_gpio(unsigned irq) return -EINVAL; } +void gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, + unsigned int pin_base, unsigned int npins); +void gpiochip_remove_pin_ranges(struct gpio_chip *chip); #endif #endif /* __LINUX_GPIO_H */ diff --git a/include/linux/pinctrl/pinctrl.h b/include/linux/pinctrl/pinctrl.h index eda04674633dd9ded2dd7cdcca293e3a8a87234a..434e5a94e131ab5ee9b04024a0fcfa8979071da0 100644 --- a/include/linux/pinctrl/pinctrl.h +++ b/include/linux/pinctrl/pinctrl.h @@ -136,6 +136,23 @@ extern void pinctrl_add_gpio_ranges(struct pinctrl_dev *pctldev, unsigned nranges); extern void pinctrl_remove_gpio_range(struct pinctrl_dev *pctldev, struct pinctrl_gpio_range *range); + +extern struct pinctrl_dev *find_pinctrl_and_add_gpio_range(const char *devname, + struct pinctrl_gpio_range *range); + +#ifdef CONFIG_OF +extern struct pinctrl_dev *of_pinctrl_add_gpio_range(struct device_node *np, + struct pinctrl_gpio_range *range); +#else +static inline +struct pinctrl_dev *of_pinctrl_add_gpio_range(struct device_node *np, + struct pinctrl_gpio_range *range) +{ + return NULL; +} + +#endif /* CONFIG_OF */ + extern const char *pinctrl_dev_get_name(struct pinctrl_dev *pctldev); extern void *pinctrl_dev_get_drvdata(struct pinctrl_dev *pctldev); #else