diff options
| -rw-r--r-- | drivers/gpio/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/gpio/Makefile | 1 | ||||
| -rw-r--r-- | drivers/gpio/gpio-delay.c | 139 |
3 files changed, 148 insertions, 0 deletions
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 60c5c54688e..f69919abc05 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -1,3 +1,11 @@ +config GPIO_DELAY + bool "GPIO delay driver" + depends on DM_GPIO + help + Enable the GPIO delay driver. + This driver allows wrapping another GPIO controller and inserting + ramp-up/ramp-down delays on output changes, as described in the + Linux gpio-delay binding. # # GPIO infrastructure and drivers # diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 910478c0c7a..fec258f59f5 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -21,6 +21,7 @@ obj-$(CONFIG_ATMEL_PIO4) += atmel_pio4.o obj-$(CONFIG_BCM6345_GPIO) += bcm6345_gpio.o obj-$(CONFIG_CORTINA_GPIO) += cortina_gpio.o obj-$(CONFIG_FXL6408_GPIO) += gpio-fxl6408.o +obj-$(CONFIG_GPIO_DELAY) += gpio-delay.o obj-$(CONFIG_INTEL_GPIO) += intel_gpio.o obj-$(CONFIG_INTEL_ICH6_GPIO) += intel_ich6_gpio.o obj-$(CONFIG_INTEL_BROADWELL_GPIO) += intel_broadwell_gpio.o diff --git a/drivers/gpio/gpio-delay.c b/drivers/gpio/gpio-delay.c new file mode 100644 index 00000000000..9105deecc4f --- /dev/null +++ b/drivers/gpio/gpio-delay.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2025 - 2026, Advanced Micro Devices, Inc. + * + * Michal Simek <[email protected]> + */ + +#include <dm.h> +#include <dm/device_compat.h> +#include <dm/devres.h> +#include <asm/gpio.h> +#include <linux/delay.h> + +struct gpio_delay_desc { + struct gpio_desc real_gpio; + u32 ramp_up_us; + u32 ramp_down_us; +}; + +struct gpio_delay_priv { + struct gpio_delay_desc *descs; +}; + +static int gpio_delay_direction_input(struct udevice *dev, unsigned int offset) +{ + return -ENOSYS; +} + +static int gpio_delay_get_value(struct udevice *dev, unsigned int offset) +{ + return -ENOSYS; +} + +static int gpio_delay_set_value(struct udevice *dev, unsigned int offset, + int value) +{ + struct gpio_delay_priv *priv = dev_get_priv(dev); + struct gpio_delay_desc *desc = &priv->descs[offset]; + u32 wait; + int ret; + + dev_dbg(dev, "gpio %d set to %d\n", offset, value); + + ret = dm_gpio_set_value(&desc->real_gpio, value); + if (ret) { + dev_err(dev, "Failed to set gpio %d, value %d\n", offset, value); + return ret; + } + + if (value) + wait = desc->ramp_up_us; + else + wait = desc->ramp_down_us; + + udelay(wait); + + dev_dbg(dev, "waited for %d us\n", wait); + + return 0; +} + +static int gpio_delay_direction_output(struct udevice *dev, unsigned int offset, + int value) +{ + return gpio_delay_set_value(dev, offset, value); +} + +static int gpio_delay_xlate(struct udevice *dev, struct gpio_desc *desc, + struct ofnode_phandle_args *args) +{ + struct gpio_delay_priv *priv = dev_get_priv(dev); + + if (args->args_count < 3) + return -EINVAL; + + if (args->args[0] >= 32) + return -EINVAL; + + struct gpio_delay_desc *d = &priv->descs[args->args[0]]; + + d->ramp_up_us = args->args[1]; + d->ramp_down_us = args->args[2]; + + dev_dbg(dev, "pin: %d, ramp_up_us: %d, ramp_down_us: %d\n", + args->args[0], d->ramp_up_us, d->ramp_down_us); + + return 0; +} + +static const struct dm_gpio_ops gpio_delay_ops = { + .direction_output = gpio_delay_direction_output, + .direction_input = gpio_delay_direction_input, + .get_value = gpio_delay_get_value, + .set_value = gpio_delay_set_value, + .xlate = gpio_delay_xlate, +}; + +static int gpio_delay_probe(struct udevice *dev) +{ + struct gpio_delay_priv *priv = dev_get_priv(dev); + struct gpio_delay_desc *d; + ofnode node = dev_ofnode(dev); + int i = 0, ret, ngpio; + + ngpio = gpio_get_list_count(dev, "gpios"); + if (ngpio < 0) + return ngpio; + + dev_dbg(dev, "gpios: %d\n", ngpio); + + priv->descs = devm_kmalloc_array(dev, ngpio, sizeof(*d), GFP_KERNEL); + if (!priv->descs) + return -ENOMEM; + + /* Request all GPIOs described in the controller node */ + for (i = 0; i < ngpio; i++) { + d = &priv->descs[i]; + ret = gpio_request_by_name_nodev(node, "gpios", i, + &d->real_gpio, 0); + if (ret) + return ret; + } + + return 0; +} + +static const struct udevice_id gpio_delay_ids[] = { + { .compatible = "gpio-delay" }, + { } +}; + +U_BOOT_DRIVER(gpio_delay) = { + .name = "gpio-delay", + .id = UCLASS_GPIO, + .of_match = gpio_delay_ids, + .ops = &gpio_delay_ops, + .priv_auto = sizeof(struct gpio_delay_priv), + .probe = gpio_delay_probe, +}; |