From: Alexander Sverdlin <alexander.sverd...@siemens.com>

Add driver for TI LP8864, LP8864S, LP8866 4/6 channel LED-backlight drivers
with I2C interface.

Link: https://www.ti.com/lit/gpn/lp8866-q1
Link: https://www.ti.com/lit/gpn/lp8864-q1
Link: https://www.ti.com/lit/gpn/lp8864s-q1
Signed-off-by: Alexander Sverdlin <alexander.sverd...@siemens.com>
---
 MAINTAINERS                |   7 +
 drivers/leds/Kconfig       |  12 ++
 drivers/leds/Makefile      |   1 +
 drivers/leds/leds-lp8864.c | 320 +++++++++++++++++++++++++++++++++++++
 4 files changed, 340 insertions(+)
 create mode 100644 drivers/leds/leds-lp8864.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 21f855fe468bc..14e87b6b37b8a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -23262,6 +23262,13 @@ S:     Supported
 F:     Documentation/devicetree/bindings/iio/dac/ti,dac7612.yaml
 F:     drivers/iio/dac/ti-dac7612.c
 
+TEXAS INSTRUMENTS' LB8864 LED BACKLIGHT DRIVER
+M:     Alexander Sverdlin <alexander.sverd...@siemens.com>
+L:     linux-l...@vger.kernel.org
+S:     Maintained
+F:     Documentation/devicetree/bindings/leds/backlight/ti,lp8860.yaml
+F:     drivers/leds/leds-lp8864.c
+
 TEXAS INSTRUMENTS' SYSTEM CONTROL INTERFACE (TISCI) PROTOCOL DRIVER
 M:     Nishanth Menon <n...@ti.com>
 M:     Tero Kristo <kri...@kernel.org>
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index b784bb74a8378..6d0e88e501614 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -511,6 +511,18 @@ config LEDS_LP8860
          on the LP8860 4 channel LED driver using the I2C communication
          bus.
 
+config LEDS_LP8864
+       tristate "LED support for the TI LP8864/LP8866 4/6 channel LED drivers"
+       depends on LEDS_CLASS && I2C && OF
+       select REGMAP_I2C
+       help
+         If you say yes here you get support for the TI LP8864-Q1,
+         LP8864S-Q1, LP8866-Q1, LP8866S-Q1 4/6 channel LED backlight
+         drivers with I2C interface.
+
+         To compile this driver as a module, choose M here: the
+         module will be called leds-lp8864.
+
 config LEDS_CLEVO_MAIL
        tristate "Mail LED on Clevo notebook"
        depends on LEDS_CLASS && BROKEN
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 18afbb5a23ee5..f66bf2e13665f 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -57,6 +57,7 @@ obj-$(CONFIG_LEDS_LP55XX_COMMON)      += leds-lp55xx-common.o
 obj-$(CONFIG_LEDS_LP8501)              += leds-lp8501.o
 obj-$(CONFIG_LEDS_LP8788)              += leds-lp8788.o
 obj-$(CONFIG_LEDS_LP8860)              += leds-lp8860.o
+obj-$(CONFIG_LEDS_LP8864)              += leds-lp8864.o
 obj-$(CONFIG_LEDS_LT3593)              += leds-lt3593.o
 obj-$(CONFIG_LEDS_MAX5970)             += leds-max5970.o
 obj-$(CONFIG_LEDS_MAX77650)            += leds-max77650.o
diff --git a/drivers/leds/leds-lp8864.c b/drivers/leds/leds-lp8864.c
new file mode 100644
index 0000000000000..da02e29bbf4b7
--- /dev/null
+++ b/drivers/leds/leds-lp8864.c
@@ -0,0 +1,320 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TI LP8864/LP8866 4/6 Channel LED Driver
+ *
+ * Copyright (C) 2024 Siemens AG
+ *
+ * Based on LP8860 driver by Dan Murphy <dmur...@ti.com>
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+#define LP8864_BRT_CONTROL             0x00
+#define LP8864_USER_CONFIG1            0x04
+#define   LP8864_BRT_MODE_MASK         GENMASK(9, 8)
+/* Brightness controlled by DISPLAY_BRT register */
+#define   LP8864_BRT_MODE_REG          BIT(9)
+#define LP8864_SUPPLY_STATUS           0x0e
+#define LP8864_BOOST_STATUS            0x10
+#define LP8864_LED_STATUS              0x12
+/* Writeable bits in the LED_STATUS register */
+#define   LP8864_LED_STATUS_WR_MASK    GENMASK(14, 9)
+
+/* Textual meaning for every register bit */
+static const char *const lp8864_supply_status_msg[] = {
+       NULL, "Vin under-voltage fault",
+       NULL, "Vin over-voltage fault",
+       NULL, "Vdd under-voltage fault",
+       NULL, "Vin over-current fault",
+       NULL, "Missing charge pump fault",
+       NULL, "Charge pump fault",
+       NULL, "Missing boost sync fault",
+       NULL, "CRC error fault ",
+};
+
+/* Textual meaning for every register bit */
+static const char *const lp8864_boost_status_msg[] = {
+       NULL, "Boost OVP low fault",
+       NULL, "Boost OVP high fault",
+       NULL, "Boost over-current fault",
+       NULL, "Missing boost FSET resistor fault",
+       NULL, "Missing MODE SEL resistor fault",
+       NULL, "Missing LED resistor fault",
+       NULL, "ISET resistor short to ground fault",
+       NULL, "Thermal shutdown fault",
+};
+
+/* Textual meaning for every register bit */
+static const char *const lp8864_led_status_msg[] = {
+       "LED 1 fault",
+       "LED 2 fault",
+       "LED 3 fault",
+       "LED 4 fault",
+       "LED 5 fault",
+       "LED 6 fault",
+       "LED open fault",
+       "LED internal short fault",
+       "LED short to GND fault",
+       NULL, NULL, NULL,
+       "Invalid string configuration fault",
+       NULL,
+       "I2C time out fault",
+};
+
+/**
+ * struct lp8864_led
+ * @client: Pointer to the I2C client
+ * @led_dev: led class device pointer
+ * @regmap: Devices register map
+ * @led_status_mask: Helps to report LED fault only once
+ */
+struct lp8864_led {
+       struct i2c_client *client;
+       struct led_classdev led_dev;
+       struct regmap *regmap;
+       u16 led_status_mask;
+};
+
+static int lp8864_fault_check(struct lp8864_led *led)
+{
+       int ret, i;
+       unsigned int buf;
+
+       ret = regmap_read(led->regmap, LP8864_SUPPLY_STATUS, &buf);
+       if (ret)
+               goto err;
+
+       for (i = 0; i < ARRAY_SIZE(lp8864_supply_status_msg); i++)
+               if (lp8864_supply_status_msg[i] && buf & BIT(i))
+                       dev_err(&led->client->dev, "%s\n",
+                               lp8864_supply_status_msg[i]);
+
+       /*
+        * Clear bits have an index preceding the corresponding Status bits;
+        * both have to be written "1" simultaneously to clear the corresponding
+        * Status bit.
+        */
+       if (buf)
+               ret = regmap_write(led->regmap, LP8864_SUPPLY_STATUS,
+                                  buf >> 1 | buf);
+       if (ret)
+               goto err;
+
+       ret = regmap_read(led->regmap, LP8864_BOOST_STATUS, &buf);
+       if (ret)
+               goto err;
+
+       for (i = 0; i < ARRAY_SIZE(lp8864_boost_status_msg); i++)
+               if (lp8864_boost_status_msg[i] && buf & BIT(i))
+                       dev_err(&led->client->dev, "%s\n",
+                               lp8864_boost_status_msg[i]);
+
+       if (buf)
+               ret = regmap_write(led->regmap, LP8864_BOOST_STATUS,
+                                  buf >> 1 | buf);
+       if (ret)
+               goto err;
+
+       ret = regmap_read(led->regmap, LP8864_LED_STATUS, &buf);
+       if (ret)
+               goto err;
+
+       /*
+        * Clear already reported faults that maintain their value until device
+        * power-down
+        */
+       buf &= ~led->led_status_mask;
+
+       for (i = 0; i < ARRAY_SIZE(lp8864_led_status_msg); i++)
+               if (lp8864_led_status_msg[i] && buf & BIT(i))
+                       dev_err(&led->client->dev, "%s\n",
+                               lp8864_led_status_msg[i]);
+
+       /*
+        * Mark those which maintain their value until device power-down as
+        * "already reported"
+        */
+       led->led_status_mask |= buf & ~LP8864_LED_STATUS_WR_MASK;
+
+       /*
+        * Only bits 14, 12, 10 have to be cleared here, but others are RO,
+        * we don't care what we write to them.
+        */
+       if (buf & LP8864_LED_STATUS_WR_MASK)
+               ret = regmap_write(led->regmap, LP8864_LED_STATUS,
+                                  buf >> 1 | buf);
+       if (ret)
+               goto err;
+
+       return 0;
+
+err:
+       dev_err(&led->client->dev, "Cannot read/clear faults (%pe)\n",
+               ERR_PTR(ret));
+
+       return ret;
+}
+
+static int lp8864_brightness_set(struct led_classdev *led_cdev,
+                                enum led_brightness brt_val)
+{
+       struct lp8864_led *led = container_of(led_cdev, struct lp8864_led,
+                                             led_dev);
+       unsigned int val = brt_val * 0xffff / LED_FULL;
+       int ret;
+
+       ret = lp8864_fault_check(led);
+       if (ret)
+               return ret;
+
+       ret = regmap_write(led->regmap, LP8864_BRT_CONTROL, val);
+       if (ret)
+               dev_err(&led->client->dev, "Cannot write BRT_CONTROL\n");
+
+       return ret;
+}
+
+static enum led_brightness lp8864_brightness_get(struct led_classdev *led_cdev)
+{
+       struct lp8864_led *led = container_of(led_cdev, struct lp8864_led,
+                                             led_dev);
+       unsigned int buf;
+       int ret;
+
+       ret = regmap_read(led->regmap, LP8864_BRT_CONTROL, &buf);
+       if (ret) {
+               dev_err(&led->client->dev, "Cannot read BRT_CONTROL\n");
+               return ret;
+       }
+
+       return buf * LED_FULL / 0xffff;
+}
+
+static int lp8864_init(struct lp8864_led *led)
+{
+       int ret;
+
+       /* Control brightness by DISPLAY_BRT register */
+       ret = regmap_update_bits(led->regmap, LP8864_USER_CONFIG1,
+                                LP8864_BRT_MODE_MASK, LP8864_BRT_MODE_REG);
+       if (ret) {
+               dev_err(&led->client->dev, "Cannot write USER_CONFIG1\n");
+               return ret;
+       }
+
+       return lp8864_fault_check(led);
+}
+
+static const struct regmap_config lp8864_regmap_config = {
+       .reg_bits               = 8,
+       .val_bits               = 16,
+       .val_format_endian      = REGMAP_ENDIAN_LITTLE,
+       .cache_type             = REGCACHE_NONE,
+};
+
+static void lp8864_disable_gpio(void *data)
+{
+       struct gpio_desc *gpio = data;
+
+       gpiod_set_value(gpio, 0);
+}
+
+static int lp8864_probe(struct i2c_client *client)
+{
+       int ret;
+       struct lp8864_led *led;
+       struct device_node *np = dev_of_node(&client->dev);
+       struct device_node *child_node;
+       struct led_init_data init_data = {};
+       struct gpio_desc *enable_gpio;
+
+       led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
+       if (!led)
+               return -ENOMEM;
+
+       child_node = of_get_next_available_child(np, NULL);
+       if (!child_node) {
+               dev_err(&client->dev, "No LED function defined\n");
+               return -EINVAL;
+       }
+
+       ret = devm_regulator_get_enable_optional(&client->dev, "vled");
+       if (ret && ret != -ENODEV)
+               return dev_err_probe(&client->dev, ret,
+                                    "Failed to enable vled regulator (%pe)\n",
+                                    ERR_PTR(ret));
+
+       enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
+                                             GPIOD_OUT_HIGH);
+       if (IS_ERR(enable_gpio))
+               return dev_err_probe(&client->dev, PTR_ERR(enable_gpio),
+                                    "Failed to get enable GPIO (%pe)\n",
+                                    enable_gpio);
+
+       ret = devm_add_action_or_reset(&client->dev, lp8864_disable_gpio,
+                                      enable_gpio);
+
+       led->client = client;
+       led->led_dev.brightness_set_blocking = lp8864_brightness_set;
+       led->led_dev.brightness_get = lp8864_brightness_get;
+
+       i2c_set_clientdata(client, led);
+
+       led->regmap = devm_regmap_init_i2c(client, &lp8864_regmap_config);
+       if (IS_ERR(led->regmap)) {
+               dev_err(&client->dev, "Failed to allocate register map (%pe)\n",
+                       led->regmap);
+               return PTR_ERR(led->regmap);
+       }
+
+       ret = lp8864_init(led);
+       if (ret)
+               return ret;
+
+       init_data.fwnode = of_fwnode_handle(child_node);
+       init_data.devicename = "lp8864";
+       init_data.default_label = ":display_cluster";
+
+       ret = devm_led_classdev_register_ext(&client->dev, &led->led_dev,
+                                            &init_data);
+       if (ret)
+               dev_err(&client->dev, "Failed to register LED device (%pe)\n",
+                       ERR_PTR(ret));
+
+       return ret;
+}
+
+static const struct i2c_device_id lp8864_id[] = {
+       { "lp8864" },
+       {}
+};
+MODULE_DEVICE_TABLE(i2c, lp8864_id);
+
+static const struct of_device_id of_lp8864_leds_match[] = {
+       { .compatible = "ti,lp8864" },
+       {}
+};
+MODULE_DEVICE_TABLE(of, of_lp8864_leds_match);
+
+static struct i2c_driver lp8864_driver = {
+       .driver = {
+               .name   = "lp8864",
+               .of_match_table = of_lp8864_leds_match,
+       },
+       .probe          = lp8864_probe,
+       .id_table       = lp8864_id,
+};
+module_i2c_driver(lp8864_driver);
+
+MODULE_DESCRIPTION("Texas Instruments LP8864/LP8866 LED driver");
+MODULE_AUTHOR("Alexander Sverdlin <alexander.sverd...@siemens.com>");
+MODULE_LICENSE("GPL");
-- 
2.47.1

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