diff options
Diffstat (limited to 'drivers/leds/leds-lm36274.c')
| -rw-r--r-- | drivers/leds/leds-lm36274.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/drivers/leds/leds-lm36274.c b/drivers/leds/leds-lm36274.c new file mode 100644 index 000000000000..ed9dc857ec8f --- /dev/null +++ b/drivers/leds/leds-lm36274.c @@ -0,0 +1,172 @@ +// SPDX-License-Identifier: GPL-2.0 +// TI LM36274 LED chip family driver +// Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/ + +#include <linux/bitops.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/leds.h> +#include <linux/leds-ti-lmu-common.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> + +#include <linux/mfd/ti-lmu.h> +#include <linux/mfd/ti-lmu-register.h> + +#include <uapi/linux/uleds.h> + +#define LM36274_MAX_STRINGS 4 +#define LM36274_BL_EN BIT(4) + +/** + * struct lm36274 + * @pdev: platform device + * @led_dev: led class device + * @lmu_data: Register and setting values for common code + * @regmap: Devices register map + * @dev: Pointer to the devices device struct + * @led_sources - The LED strings supported in this array + * @num_leds - Number of LED strings are supported in this array + */ +struct lm36274 { + struct platform_device *pdev; + struct led_classdev led_dev; + struct ti_lmu_bank lmu_data; + struct regmap *regmap; + struct device *dev; + + u32 led_sources[LM36274_MAX_STRINGS]; + int num_leds; +}; + +static int lm36274_brightness_set(struct led_classdev *led_cdev, + enum led_brightness brt_val) +{ + struct lm36274 *led = container_of(led_cdev, struct lm36274, led_dev); + + return ti_lmu_common_set_brightness(&led->lmu_data, brt_val); +} + +static int lm36274_init(struct lm36274 *lm36274_data) +{ + int enable_val = 0; + int i; + + for (i = 0; i < lm36274_data->num_leds; i++) + enable_val |= (1 << lm36274_data->led_sources[i]); + + if (!enable_val) { + dev_err(lm36274_data->dev, "No LEDs were enabled\n"); + return -EINVAL; + } + + enable_val |= LM36274_BL_EN; + + return regmap_write(lm36274_data->regmap, LM36274_REG_BL_EN, + enable_val); +} + +static int lm36274_parse_dt(struct lm36274 *lm36274_data) +{ + struct fwnode_handle *child = NULL; + char label[LED_MAX_NAME_SIZE]; + struct device *dev = &lm36274_data->pdev->dev; + const char *name; + int child_cnt; + int ret = -EINVAL; + + /* There should only be 1 node */ + child_cnt = device_get_child_node_count(dev); + if (child_cnt != 1) + return -EINVAL; + + device_for_each_child_node(dev, child) { + ret = fwnode_property_read_string(child, "label", &name); + if (ret) + snprintf(label, sizeof(label), + "%s::", lm36274_data->pdev->name); + else + snprintf(label, sizeof(label), + "%s:%s", lm36274_data->pdev->name, name); + + lm36274_data->num_leds = fwnode_property_read_u32_array(child, + "led-sources", + NULL, 0); + if (lm36274_data->num_leds <= 0) + return -ENODEV; + + ret = fwnode_property_read_u32_array(child, "led-sources", + lm36274_data->led_sources, + lm36274_data->num_leds); + if (ret) { + dev_err(dev, "led-sources property missing\n"); + return ret; + } + + fwnode_property_read_string(child, "linux,default-trigger", + &lm36274_data->led_dev.default_trigger); + + } + + lm36274_data->lmu_data.regmap = lm36274_data->regmap; + lm36274_data->lmu_data.max_brightness = MAX_BRIGHTNESS_11BIT; + lm36274_data->lmu_data.msb_brightness_reg = LM36274_REG_BRT_MSB; + lm36274_data->lmu_data.lsb_brightness_reg = LM36274_REG_BRT_LSB; + + lm36274_data->led_dev.name = label; + lm36274_data->led_dev.max_brightness = MAX_BRIGHTNESS_11BIT; + lm36274_data->led_dev.brightness_set_blocking = lm36274_brightness_set; + + return 0; +} + +static int lm36274_probe(struct platform_device *pdev) +{ + struct ti_lmu *lmu = dev_get_drvdata(pdev->dev.parent); + struct lm36274 *lm36274_data; + int ret; + + lm36274_data = devm_kzalloc(&pdev->dev, sizeof(*lm36274_data), + GFP_KERNEL); + if (!lm36274_data) + return -ENOMEM; + + lm36274_data->pdev = pdev; + lm36274_data->dev = lmu->dev; + lm36274_data->regmap = lmu->regmap; + dev_set_drvdata(&pdev->dev, lm36274_data); + + ret = lm36274_parse_dt(lm36274_data); + if (ret) { + dev_err(lm36274_data->dev, "Failed to parse DT node\n"); + return ret; + } + + ret = lm36274_init(lm36274_data); + if (ret) { + dev_err(lm36274_data->dev, "Failed to init the device\n"); + return ret; + } + + return devm_led_classdev_register(lm36274_data->dev, + &lm36274_data->led_dev); +} + +static const struct of_device_id of_lm36274_leds_match[] = { + { .compatible = "ti,lm36274-backlight", }, + {}, +}; +MODULE_DEVICE_TABLE(of, of_lm36274_leds_match); + +static struct platform_driver lm36274_driver = { + .probe = lm36274_probe, + .driver = { + .name = "lm36274-leds", + }, +}; +module_platform_driver(lm36274_driver) + +MODULE_DESCRIPTION("Texas Instruments LM36274 LED driver"); +MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>"); +MODULE_LICENSE("GPL v2"); |