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path: root/drivers/leds/leds-lm36274.c
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Diffstat (limited to 'drivers/leds/leds-lm36274.c')
-rw-r--r--drivers/leds/leds-lm36274.c172
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");