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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/leds/leds-syscon.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/leds/leds-syscon.c')
-rw-r--r-- | drivers/leds/leds-syscon.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/drivers/leds/leds-syscon.c b/drivers/leds/leds-syscon.c new file mode 100644 index 000000000..7eddb8ecb --- /dev/null +++ b/drivers/leds/leds-syscon.c @@ -0,0 +1,140 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Generic Syscon LEDs Driver + * + * Copyright (c) 2014, Linaro Limited + * Author: Linus Walleij <linus.walleij@linaro.org> + */ +#include <linux/io.h> +#include <linux/init.h> +#include <linux/of_device.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/stat.h> +#include <linux/slab.h> +#include <linux/mfd/syscon.h> +#include <linux/regmap.h> +#include <linux/leds.h> + +/** + * struct syscon_led - state container for syscon based LEDs + * @cdev: LED class device for this LED + * @map: regmap to access the syscon device backing this LED + * @offset: the offset into the syscon regmap for the LED register + * @mask: the bit in the register corresponding to the LED + * @state: current state of the LED + */ +struct syscon_led { + struct led_classdev cdev; + struct regmap *map; + u32 offset; + u32 mask; + bool state; +}; + +static void syscon_led_set(struct led_classdev *led_cdev, + enum led_brightness value) +{ + struct syscon_led *sled = + container_of(led_cdev, struct syscon_led, cdev); + u32 val; + int ret; + + if (value == LED_OFF) { + val = 0; + sled->state = false; + } else { + val = sled->mask; + sled->state = true; + } + + ret = regmap_update_bits(sled->map, sled->offset, sled->mask, val); + if (ret < 0) + dev_err(sled->cdev.dev, "error updating LED status\n"); +} + +static int syscon_led_probe(struct platform_device *pdev) +{ + struct led_init_data init_data = {}; + struct device *dev = &pdev->dev; + struct device_node *np = dev_of_node(dev); + struct device *parent; + struct regmap *map; + struct syscon_led *sled; + const char *state; + int ret; + + parent = dev->parent; + if (!parent) { + dev_err(dev, "no parent for syscon LED\n"); + return -ENODEV; + } + map = syscon_node_to_regmap(dev_of_node(parent)); + if (IS_ERR(map)) { + dev_err(dev, "no regmap for syscon LED parent\n"); + return PTR_ERR(map); + } + + sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL); + if (!sled) + return -ENOMEM; + + sled->map = map; + + if (of_property_read_u32(np, "offset", &sled->offset)) + return -EINVAL; + if (of_property_read_u32(np, "mask", &sled->mask)) + return -EINVAL; + + state = of_get_property(np, "default-state", NULL); + if (state) { + if (!strcmp(state, "keep")) { + u32 val; + + ret = regmap_read(map, sled->offset, &val); + if (ret < 0) + return ret; + sled->state = !!(val & sled->mask); + } else if (!strcmp(state, "on")) { + sled->state = true; + ret = regmap_update_bits(map, sled->offset, + sled->mask, + sled->mask); + if (ret < 0) + return ret; + } else { + sled->state = false; + ret = regmap_update_bits(map, sled->offset, + sled->mask, 0); + if (ret < 0) + return ret; + } + } + sled->cdev.brightness_set = syscon_led_set; + + init_data.fwnode = of_fwnode_handle(np); + + ret = devm_led_classdev_register_ext(dev, &sled->cdev, &init_data); + if (ret < 0) + return ret; + + platform_set_drvdata(pdev, sled); + dev_info(dev, "registered LED %s\n", sled->cdev.name); + + return 0; +} + +static const struct of_device_id of_syscon_leds_match[] = { + { .compatible = "register-bit-led", }, + {}, +}; + +static struct platform_driver syscon_led_driver = { + .probe = syscon_led_probe, + .driver = { + .name = "leds-syscon", + .of_match_table = of_syscon_leds_match, + .suppress_bind_attrs = true, + }, +}; +builtin_platform_driver(syscon_led_driver); |