From ecbd9c87f073f097d9fe56390353e64e963e866a Mon Sep 17 00:00:00 2001 From: John Crispin Date: Tue, 6 Mar 2018 10:03:03 +0100 Subject: [PATCH 03/27] leds: add reset-controller based driver Signed-off-by: John Crispin --- drivers/leds/Kconfig | 11 ++++ drivers/leds/Makefile | 1 + drivers/leds/leds-reset.c | 137 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 149 insertions(+) create mode 100644 drivers/leds/leds-reset.c --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -823,6 +823,17 @@ config LEDS_LM36274 Say Y to enable the LM36274 LED driver for TI LMU devices. This supports the LED device LM36274. +config LEDS_RESET + tristate "LED support for reset-controller API" + depends on LEDS_CLASS + depends on RESET_CONTROLLER + help + This option enables support for LEDs connected to pins driven by reset + controllers. Yes, DNI actual built HW like that. + + To compile this driver as a module, choose M here: the module + will be called leds-reset. + comment "LED Triggers" source "drivers/leds/trigger/Kconfig" --- /dev/null +++ b/drivers/leds/leds-reset.c @@ -0,0 +1,140 @@ +/* + * Copyright (C) 2018 John Crispin + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ +#include +#include +#include +#include +#include +#include +#include +#include + +struct reset_led_data { + struct led_classdev cdev; + struct reset_control *rst; +}; + +static inline struct reset_led_data * + cdev_to_reset_led_data(struct led_classdev *led_cdev) +{ + return container_of(led_cdev, struct reset_led_data, cdev); +} + +static void reset_led_set(struct led_classdev *led_cdev, + enum led_brightness value) +{ + struct reset_led_data *led_dat = cdev_to_reset_led_data(led_cdev); + + if (value == LED_OFF) + reset_control_assert(led_dat->rst); + else + reset_control_deassert(led_dat->rst); +} + +struct reset_leds_priv { + int num_leds; + struct reset_led_data leds[]; +}; + +static inline int sizeof_reset_leds_priv(int num_leds) +{ + return sizeof(struct reset_leds_priv) + + (sizeof(struct reset_led_data) * num_leds); +} + +static struct reset_leds_priv *reset_leds_create(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct fwnode_handle *child; + struct reset_leds_priv *priv; + int count, ret; + + count = device_get_child_node_count(dev); + if (!count) + return ERR_PTR(-ENODEV); + + priv = devm_kzalloc(dev, sizeof_reset_leds_priv(count), GFP_KERNEL); + if (!priv) + return ERR_PTR(-ENOMEM); + + device_for_each_child_node(dev, child) { + struct reset_led_data *led = &priv->leds[priv->num_leds]; + struct device_node *np = to_of_node(child); + + ret = fwnode_property_read_string(child, "label", &led->cdev.name); + if (!led->cdev.name) { + fwnode_handle_put(child); + return ERR_PTR(-EINVAL); + } + led->rst = __of_reset_control_get(np, NULL, 0, 0, 0, true); + if (IS_ERR(led->rst)) + return ERR_PTR(-EINVAL); + + fwnode_property_read_string(child, "linux,default-trigger", + &led->cdev.default_trigger); + + led->cdev.brightness_set = reset_led_set; + ret = devm_led_classdev_register(&pdev->dev, &led->cdev); + if (ret < 0) + return ERR_PTR(ret); + led->cdev.dev->of_node = np; + priv->num_leds++; + } + + return priv; +} + +static const struct of_device_id of_reset_leds_match[] = { + { .compatible = "reset-leds", }, + {}, +}; + +MODULE_DEVICE_TABLE(of, of_reset_leds_match); + +static int reset_led_probe(struct platform_device *pdev) +{ + struct reset_leds_priv *priv; + + priv = reset_leds_create(pdev); + if (IS_ERR(priv)) + return PTR_ERR(priv); + + platform_set_drvdata(pdev, priv); + + return 0; +} + +static void reset_led_shutdown(struct platform_device *pdev) +{ + struct reset_leds_priv *priv = platform_get_drvdata(pdev); + int i; + + for (i = 0; i < priv->num_leds; i++) { + struct reset_led_data *led = &priv->leds[i]; + + if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN)) + reset_led_set(&led->cdev, LED_OFF); + } +} + +static struct platform_driver reset_led_driver = { + .probe = reset_led_probe, + .shutdown = reset_led_shutdown, + .driver = { + .name = "leds-reset", + .of_match_table = of_reset_leds_match, + }, +}; + +module_platform_driver(reset_led_driver); + +MODULE_AUTHOR("John Crispin "); +MODULE_DESCRIPTION("reset controller LED driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:leds-reset"); --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -85,6 +85,7 @@ obj-$(CONFIG_LEDS_LM3601X) += leds-lm36 obj-$(CONFIG_LEDS_TI_LMU_COMMON) += leds-ti-lmu-common.o obj-$(CONFIG_LEDS_LM3697) += leds-lm3697.o obj-$(CONFIG_LEDS_LM36274) += leds-lm36274.o +obj-$(CONFIG_LEDS_RESET) += leds-reset.o # LED SPI Drivers obj-$(CONFIG_LEDS_CR0014114) += leds-cr0014114.o