diff options
author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2023-06-15 16:20:22 +0300 |
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committer | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2023-06-16 12:02:07 +0300 |
commit | 81674bea191301396a2ebd73a49a2e61e723c3d9 (patch) | |
tree | 8a2ac564c34f38cd97f9c8391e71c60a59d1d4a1 /drivers/gpio/gpio-aggregator.c | |
parent | b466622cecb9b14577ff0ed3e0bc4756dbe1d3d3 (diff) | |
download | linux-81674bea191301396a2ebd73a49a2e61e723c3d9.tar.xz |
gpio: aggregator: Set up a parser of delay line parameters
The aggregator mode can also handle properties of the platform,
that do not belong to the GPIO controller itself. One of such
a property is a signal delay line. Set up a parser to support it.
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Diffstat (limited to 'drivers/gpio/gpio-aggregator.c')
-rw-r--r-- | drivers/gpio/gpio-aggregator.c | 72 |
1 files changed, 70 insertions, 2 deletions
diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c index 4a470dd8b75d..38e0fff9afe7 100644 --- a/drivers/gpio/gpio-aggregator.c +++ b/drivers/gpio/gpio-aggregator.c @@ -18,6 +18,7 @@ #include <linux/mutex.h> #include <linux/overflow.h> #include <linux/platform_device.h> +#include <linux/property.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/string.h> @@ -422,6 +423,59 @@ static int gpio_fwd_to_irq(struct gpio_chip *chip, unsigned int offset) return gpiod_to_irq(fwd->descs[offset]); } +/* + * The GPIO delay provides a way to configure platform specific delays + * for the GPIO ramp-up or ramp-down delays. This can serve the following + * purposes: + * - Open-drain output using an RC filter + */ +#define FWD_FEATURE_DELAY BIT(0) + +#ifdef CONFIG_OF_GPIO +static int gpiochip_fwd_delay_of_xlate(struct gpio_chip *chip, + const struct of_phandle_args *gpiospec, + u32 *flags) +{ + struct gpiochip_fwd *fwd = gpiochip_get_data(chip); + struct gpiochip_fwd_timing *timings; + u32 line; + + if (gpiospec->args_count != chip->of_gpio_n_cells) + return -EINVAL; + + line = gpiospec->args[0]; + if (line >= chip->ngpio) + return -EINVAL; + + timings = &fwd->delay_timings[line]; + timings->ramp_up_us = gpiospec->args[1]; + timings->ramp_down_us = gpiospec->args[2]; + + return line; +} + +static int gpiochip_fwd_setup_delay_line(struct device *dev, struct gpio_chip *chip, + struct gpiochip_fwd *fwd) +{ + fwd->delay_timings = devm_kcalloc(dev, chip->ngpio, + sizeof(*fwd->delay_timings), + GFP_KERNEL); + if (!fwd->delay_timings) + return -ENOMEM; + + chip->of_xlate = gpiochip_fwd_delay_of_xlate; + chip->of_gpio_n_cells = 3; + + return 0; +} +#else +static int gpiochip_fwd_setup_delay_line(struct device *dev, struct gpio_chip *chip, + struct gpiochip_fwd *fwd) +{ + return 0; +} +#endif /* !CONFIG_OF_GPIO */ + /** * gpiochip_fwd_create() - Create a new GPIO forwarder * @dev: Parent device pointer @@ -429,6 +483,7 @@ static int gpio_fwd_to_irq(struct gpio_chip *chip, unsigned int offset) * @descs: Array containing the GPIO descriptors to forward to. * This array must contain @ngpios entries, and must not be deallocated * before the forwarder has been destroyed again. + * @features: Bitwise ORed features as defined with FWD_FEATURE_*. * * This function creates a new gpiochip, which forwards all GPIO operations to * the passed GPIO descriptors. @@ -438,7 +493,8 @@ static int gpio_fwd_to_irq(struct gpio_chip *chip, unsigned int offset) */ static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev, unsigned int ngpios, - struct gpio_desc *descs[]) + struct gpio_desc *descs[], + unsigned long features) { const char *label = dev_name(dev); struct gpiochip_fwd *fwd; @@ -491,6 +547,12 @@ static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev, else spin_lock_init(&fwd->slock); + if (features & FWD_FEATURE_DELAY) { + error = gpiochip_fwd_setup_delay_line(dev, chip, fwd); + if (error) + return ERR_PTR(error); + } + error = devm_gpiochip_add_data(dev, chip, fwd); if (error) return ERR_PTR(error); @@ -508,6 +570,7 @@ static int gpio_aggregator_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct gpio_desc **descs; struct gpiochip_fwd *fwd; + unsigned long features; int i, n; n = gpiod_count(dev, NULL); @@ -524,7 +587,8 @@ static int gpio_aggregator_probe(struct platform_device *pdev) return PTR_ERR(descs[i]); } - fwd = gpiochip_fwd_create(dev, n, descs); + features = (uintptr_t)device_get_match_data(dev); + fwd = gpiochip_fwd_create(dev, n, descs, features); if (IS_ERR(fwd)) return PTR_ERR(fwd); @@ -533,6 +597,10 @@ static int gpio_aggregator_probe(struct platform_device *pdev) } static const struct of_device_id gpio_aggregator_dt_ids[] = { + { + .compatible = "gpio-delay", + .data = (void *)FWD_FEATURE_DELAY, + }, /* * Add GPIO-operated devices controlled from userspace below, * or use "driver_override" in sysfs. |