[PATCH v3 3/3] leds: tps68470: Add LED control for tps68470

[Kate Hsuan <hpa@redhat.com>]

There are two LED controllers, LEDA indicator LED and LEDB flash LED for
tps68470. LEDA can be enabled by setting TPS68470_ILEDCTL_ENA. Moreover,
tps68470 provides four levels of power status for LEDB. If the
properties called "ti,ledb-current" can be found, the current will be
set according to the property values. These two LEDs can be controlled
through the LED class of sysfs (tps68470-leda and tps68470-ledb).

Signed-off-by: Kate Hsuan <hpa@redhat.com>
---
 drivers/leds/Kconfig         |  12 +++
 drivers/leds/Makefile        |   1 +
 drivers/leds/leds-tps68470.c | 185 +++++++++++++++++++++++++++++++++++
 3 files changed, 198 insertions(+)
 create mode 100644 drivers/leds/leds-tps68470.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 9dbce09eabac..ab9073b2cfef 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -827,6 +827,18 @@ config LEDS_TPS6105X
 	  It is a single boost converter primarily for white LEDs and
 	  audio amplifiers.
 
+config LEDS_TPS68470
+	tristate "LED support for TI TPS68470"
+	depends on LEDS_CLASS
+	depends on INTEL_SKL_INT3472
+	help
+	  This driver supports TPS68470 PMIC with LED chip.
+	  It provides two LED controllers, with the ability to drive 2
+	  indicator LEDs and 2 flash LEDs.
+
+	  To compile this driver as a module, choose M and it will be
+	  called leds-tps68470
+
 config LEDS_IP30
 	tristate "LED support for SGI Octane machines"
 	depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index d30395d11fd8..515a69953e73 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -80,6 +80,7 @@ obj-$(CONFIG_LEDS_TCA6507)		+= leds-tca6507.o
 obj-$(CONFIG_LEDS_TI_LMU_COMMON)	+= leds-ti-lmu-common.o
 obj-$(CONFIG_LEDS_TLC591XX)		+= leds-tlc591xx.o
 obj-$(CONFIG_LEDS_TPS6105X)		+= leds-tps6105x.o
+obj-$(CONFIG_LEDS_TPS68470)		+= leds-tps68470.o
 obj-$(CONFIG_LEDS_TURRIS_OMNIA)		+= leds-turris-omnia.o
 obj-$(CONFIG_LEDS_WM831X_STATUS)	+= leds-wm831x-status.o
 obj-$(CONFIG_LEDS_WM8350)		+= leds-wm8350.o
diff --git a/drivers/leds/leds-tps68470.c b/drivers/leds/leds-tps68470.c
new file mode 100644
index 000000000000..35aeb5db89c8
--- /dev/null
+++ b/drivers/leds/leds-tps68470.c
@@ -0,0 +1,185 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * LED driver for TPS68470 PMIC
+ *
+ * Copyright (C) 2023 Red Hat
+ *
+ * Authors:
+ *	Kate Hsuan <hpa@redhat.com>
+ */
+
+#include <linux/leds.h>
+#include <linux/mfd/tps68470.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+
+#define lcdev_to_led(led_cdev) \
+	container_of(led_cdev, struct tps68470_led, lcdev)
+
+#define led_to_tps68470(led, index) \
+	container_of(led, struct tps68470_device, leds[index])
+
+enum tps68470_led_ids {
+	TPS68470_ILED_A,
+	TPS68470_ILED_B,
+	TPS68470_NUM_LEDS
+};
+
+static const char *tps68470_led_names[] = {
+	[TPS68470_ILED_A] = "tps68470-iled_a",
+	[TPS68470_ILED_B] = "tps68470-iled_b",
+};
+
+struct tps68470_led {
+	unsigned int led_id;
+	struct led_classdev lcdev;
+};
+
+struct tps68470_device {
+	struct device *dev;
+	struct regmap *regmap;
+	struct tps68470_led leds[TPS68470_NUM_LEDS];
+};
+
+enum ctrlb_current {
+	CTRLB_2MA	= 0,
+	CTRLB_4MA	= 1,
+	CTRLB_8MA	= 2,
+	CTRLB_16MA	= 3,
+};
+
+static int tps68470_brightness_set(struct led_classdev *led_cdev, enum led_brightness brightness)
+{
+	struct tps68470_led *led = lcdev_to_led(led_cdev);
+	struct tps68470_device *tps68470 = led_to_tps68470(led, led->led_id);
+	struct regmap *regmap = tps68470->regmap;
+
+	switch (led->led_id) {
+	case TPS68470_ILED_A:
+		return regmap_update_bits(regmap, TPS68470_REG_ILEDCTL, TPS68470_ILEDCTL_ENA,
+					  brightness ? TPS68470_ILEDCTL_ENA : 0);
+	case TPS68470_ILED_B:
+		return regmap_update_bits(regmap, TPS68470_REG_ILEDCTL, TPS68470_ILEDCTL_ENB,
+					  brightness ? TPS68470_ILEDCTL_ENB : 0);
+	}
+	return -EINVAL;
+}
+
+static enum led_brightness tps68470_brightness_get(struct led_classdev *led_cdev)
+{
+	struct tps68470_led *led = lcdev_to_led(led_cdev);
+	struct tps68470_device *tps68470 = led_to_tps68470(led, led->led_id);
+	struct regmap *regmap = tps68470->regmap;
+	int ret = 0;
+	int value = 0;
+
+	ret =  regmap_read(regmap, TPS68470_REG_ILEDCTL, &value);
+	if (ret)
+		return dev_err_probe(led_cdev->dev, -EINVAL, "failed on reading register\n");
+
+	switch (led->led_id) {
+	case TPS68470_ILED_A:
+		value = value & TPS68470_ILEDCTL_ENA;
+		break;
+	case TPS68470_ILED_B:
+		value = value & TPS68470_ILEDCTL_ENB;
+		break;
+	}
+
+	return value ? LED_ON : LED_OFF;
+}
+
+
+static int tps68470_ledb_current_init(struct platform_device *pdev,
+				      struct tps68470_device *tps68470)
+{
+	int ret = 0;
+	unsigned int curr;
+
+	/* configure LEDB current if the properties can be got */
+	if (!device_property_read_u32(&pdev->dev, "ti,ledb-current", &curr)) {
+		if (curr > CTRLB_16MA) {
+			dev_err(&pdev->dev,
+				"Invalid LEDB current value: %d\n",
+				curr);
+			return -EINVAL;
+		}
+		ret = regmap_update_bits(tps68470->regmap, TPS68470_REG_ILEDCTL,
+					 TPS68470_ILEDCTL_CTRLB, curr);
+	}
+	return ret;
+}
+
+static int tps68470_leds_probe(struct platform_device *pdev)
+{
+	int i = 0;
+	int ret = 0;
+	struct tps68470_device *tps68470;
+	struct tps68470_led *led;
+	struct led_classdev *lcdev;
+
+	tps68470 = devm_kzalloc(&pdev->dev, sizeof(struct tps68470_device),
+				GFP_KERNEL);
+	if (!tps68470)
+		return -ENOMEM;
+
+	tps68470->dev = &pdev->dev;
+	tps68470->regmap = dev_get_drvdata(pdev->dev.parent);
+
+	for (i = 0; i < TPS68470_NUM_LEDS; i++) {
+		led = &tps68470->leds[i];
+		lcdev = &led->lcdev;
+
+		led->led_id = i;
+
+		lcdev->name = devm_kasprintf(tps68470->dev, GFP_KERNEL, "%s::%s",
+					     tps68470_led_names[i], LED_FUNCTION_INDICATOR);
+		if (!lcdev->name)
+			return -ENOMEM;
+
+		lcdev->max_brightness = 1;
+		lcdev->brightness = 0;
+		lcdev->brightness_set_blocking = tps68470_brightness_set;
+		lcdev->brightness_get = tps68470_brightness_get;
+		lcdev->dev = &pdev->dev;
+
+		ret = devm_led_classdev_register(tps68470->dev, lcdev);
+		if (ret) {
+			dev_err_probe(tps68470->dev, ret,
+				      "error registering led\n");
+			goto err_exit;
+		}
+
+		if (i == TPS68470_ILED_B) {
+			ret = tps68470_ledb_current_init(pdev, tps68470);
+			if (ret)
+				goto err_exit;
+		}
+	}
+
+err_exit:
+	if (ret) {
+		for (i = 0; i < TPS68470_NUM_LEDS; i++) {
+			if (tps68470->leds[i].lcdev.name)
+				devm_led_classdev_unregister(&pdev->dev,
+							     &tps68470->leds[i].lcdev);
+		}
+	}
+
+	return ret;
+}
+static struct platform_driver tps68470_led_driver = {
+	.driver = {
+		   .name = "tps68470-led",
+	},
+	.probe = tps68470_leds_probe,
+};
+
+module_platform_driver(tps68470_led_driver);
+
+MODULE_ALIAS("platform:tps68470-led");
+MODULE_DESCRIPTION("LED driver for TPS68470 PMIC");
+MODULE_LICENSE("GPL v2");
-- 
2.39.2