[PATCH 3/4] leds: Add LED support for MT6323 PMIC
From: sean.wang
Date: Sun Jan 22 2017 - 22:55:11 EST
From: Sean Wang <sean.wang@xxxxxxxxxxxx>
MT6323 PMIC is a multi-function device that includes
LED function. It allows attaching upto 4 LEDs which can
either be on, off or dimmed and/or blinked with the the
controller.
Signed-off-by: Sean Wang <sean.wang@xxxxxxxxxxxx>
---
drivers/leds/Kconfig | 8 +
drivers/leds/Makefile | 1 +
drivers/leds/leds-mt6323.c | 391 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 400 insertions(+)
create mode 100644 drivers/leds/leds-mt6323.c
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index c621cbb..30095fc 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -117,6 +117,14 @@ config LEDS_MIKROTIK_RB532
This option enables support for the so called "User LED" of
Mikrotik's Routerboard 532.
+config LEDS_MT6323
+ tristate "LED Support for Mediatek MT6323 PMIC"
+ depends on LEDS_CLASS
+ depends on MFD_MT6397
+ help
+ This option enables support for on-chip LED drivers found on
+ Mediatek MT6323 PMIC.
+
config LEDS_S3C24XX
tristate "LED Support for Samsung S3C24XX GPIO LEDs"
depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 6b82737..4feb332 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -72,6 +72,7 @@ obj-$(CONFIG_LEDS_IS31FL32XX) += leds-is31fl32xx.o
obj-$(CONFIG_LEDS_PM8058) += leds-pm8058.o
obj-$(CONFIG_LEDS_MLXCPLD) += leds-mlxcpld.o
obj-$(CONFIG_LEDS_NIC78BX) += leds-nic78bx.o
+obj-$(CONFIG_LEDS_MT6323) += leds-mt6323.o
# LED SPI Drivers
obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o
diff --git a/drivers/leds/leds-mt6323.c b/drivers/leds/leds-mt6323.c
new file mode 100644
index 0000000..de3006d
--- /dev/null
+++ b/drivers/leds/leds-mt6323.c
@@ -0,0 +1,391 @@
+/*
+ * LED driver for Mediatek MT6323 PMIC
+ *
+ * Copyright (C) 2017 Sean Wang <sean.wang@xxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/leds.h>
+#include <linux/regmap.h>
+#include <linux/mfd/mt6397/core.h>
+#include <linux/mfd/mt6323/registers.h>
+#include <linux/module.h>
+
+/* Register to enable 32K clock common for LED device */
+#define MTK_MT6323_TOP_CKPDN0 0x0102
+#define RG_DRV_32K_CK_PDN BIT(11)
+#define RG_DRV_32K_CK_PDN_MASK BIT(11)
+
+/* Register to enable individual clock for LED device */
+#define MTK_MT6323_TOP_CKPDN2 0x010E
+#define RG_ISINK_CK_PDN(i) BIT(i)
+#define RG_ISINK_CK_PDN_MASK(i) BIT(i)
+
+/* Register to select clock source */
+#define MTK_MT6323_TOP_CKCON1 0x0126
+#define RG_ISINK_CK_SEL_MASK(i) (BIT(10) << (i))
+
+/* Register to setup the duty cycle of the blink */
+#define MTK_MT6323_ISINK_CON0(i) (0x0330 + 0x8 * (i))
+#define ISINK_DIM_DUTY(i) (((i) << 8) & GENMASK(12, 8))
+#define ISINK_DIM_DUTY_MASK GENMASK(12, 8)
+
+/* Register to setup the period of the blink */
+#define MTK_MT6323_ISINK_CON1(i) (0x0332 + 0x8 * (i))
+#define ISINK_DIM_FSEL(i) ((i) & GENMASK(15, 0))
+#define ISINK_DIM_FSEL_MASK GENMASK(15, 0)
+
+/* Register to control the brightness */
+#define MTK_MT6323_ISINK_CON2(i) (0x0334 + 0x8 * (i))
+#define ISINK_CH_STEP(i) (((i) << 12) & GENMASK(14, 12))
+#define ISINK_CH_STEP_MASK GENMASK(14, 12)
+#define ISINK_SFSTR0_TC(i) (((i) << 1) & GENMASK(2, 1))
+#define ISINK_SFSTR0_TC_MASK GENMASK(2, 1)
+#define ISINK_SFSTR0_EN BIT(0)
+#define ISINK_SFSTR0_EN_MASK BIT(0)
+
+/* Register to LED channel enablement */
+#define MTK_MT6323_ISINK_EN_CTRL 0x0356
+#define ISINK_CH_EN(i) BIT(i)
+#define ISINK_CH_EN_MASK(i) BIT(i)
+
+#define MTK_MAX_PERIOD 10000
+#define MTK_MAX_DEVICES 4
+#define MTK_MAX_BRIGHTNESS 6
+
+struct mtk_led;
+struct mtk_leds;
+
+/**
+ * struct mtk_led - state container for the LED device
+ * @id: the identifier in MT6323 LED device
+ * @parent: the pointer to MT6323 LED controller
+ * @cdev: LED class device for this LED device
+ * @current_brightness: current state of the LED device
+ */
+struct mtk_led {
+ int id;
+ struct mtk_leds *parent;
+ struct led_classdev cdev;
+ u8 current_brightness;
+};
+
+/* struct mtk_leds - state container for holding LED controller
+ * of the driver
+ * @dev: The device pointer
+ * @hw: The underlying hardware providing shared
+ bus for the register operations
+ * @led_num: How much the LED device the controller could control
+ * @lock: The lock among process context
+ * @led: The array that contains the state of individual
+ LED device
+ */
+struct mtk_leds {
+ struct device *dev;
+ struct mt6397_chip *hw;
+ u8 led_num;
+ /* protect among process context */
+ struct mutex lock;
+ struct mtk_led led[4];
+};
+
+static void mtk_led_hw_off(struct led_classdev *cdev)
+{
+ struct mtk_led *led = container_of(cdev, struct mtk_led, cdev);
+ struct mtk_leds *leds = led->parent;
+ struct regmap *regmap = leds->hw->regmap;
+ unsigned int status;
+
+ status = ISINK_CH_EN(led->id);
+ regmap_update_bits(regmap, MTK_MT6323_ISINK_EN_CTRL,
+ ISINK_CH_EN_MASK(led->id), ~status);
+
+ usleep_range(100, 300);
+ regmap_update_bits(regmap, MTK_MT6323_TOP_CKPDN2,
+ RG_ISINK_CK_PDN_MASK(led->id),
+ RG_ISINK_CK_PDN(led->id));
+
+ dev_dbg(leds->dev, "%s called for led%d\n",
+ __func__, led->id);
+}
+
+static u8 get_mtk_led_hw_brightness(struct led_classdev *cdev)
+{
+ struct mtk_led *led = container_of(cdev, struct mtk_led, cdev);
+ struct mtk_leds *leds = led->parent;
+ struct regmap *regmap = leds->hw->regmap;
+ unsigned int status;
+
+ regmap_read(regmap, MTK_MT6323_TOP_CKPDN2, &status);
+ if (status & RG_ISINK_CK_PDN_MASK(led->id))
+ return 0;
+
+ regmap_read(regmap, MTK_MT6323_ISINK_EN_CTRL, &status);
+ if (!(status & ISINK_CH_EN(led->id)))
+ return 0;
+
+ regmap_read(regmap, MTK_MT6323_ISINK_CON2(led->id), &status);
+ return ((status & ISINK_CH_STEP_MASK) >> 12) + 1;
+}
+
+static void mtk_led_hw_on(struct led_classdev *cdev)
+{
+ struct mtk_led *led = container_of(cdev, struct mtk_led, cdev);
+ struct mtk_leds *leds = led->parent;
+ struct regmap *regmap = leds->hw->regmap;
+ unsigned int status;
+
+ /* Setup required clock source, enable the corresponding
+ * clock and channel and let work with continuous blink as
+ * the default
+ */
+ regmap_update_bits(regmap, MTK_MT6323_TOP_CKCON1,
+ RG_ISINK_CK_SEL_MASK(led->id), 0);
+
+ status = RG_ISINK_CK_PDN(led->id);
+ regmap_update_bits(regmap, MTK_MT6323_TOP_CKPDN2,
+ RG_ISINK_CK_PDN_MASK(led->id), ~status);
+
+ usleep_range(100, 300);
+
+ regmap_update_bits(regmap, MTK_MT6323_ISINK_EN_CTRL,
+ ISINK_CH_EN_MASK(led->id),
+ ISINK_CH_EN(led->id));
+
+ regmap_update_bits(regmap, MTK_MT6323_ISINK_CON2(led->id),
+ ISINK_CH_STEP_MASK,
+ ISINK_CH_STEP(1));
+
+ regmap_update_bits(regmap, MTK_MT6323_ISINK_CON0(led->id),
+ ISINK_DIM_DUTY_MASK, ISINK_DIM_DUTY(31));
+
+ regmap_update_bits(regmap, MTK_MT6323_ISINK_CON1(led->id),
+ ISINK_DIM_FSEL_MASK, ISINK_DIM_FSEL(1000));
+
+ led->current_brightness = 1;
+
+ dev_dbg(leds->dev, "%s called for led%d\n",
+ __func__, led->id);
+}
+
+static int mtk_led_set_blink(struct led_classdev *cdev,
+ unsigned long *delay_on,
+ unsigned long *delay_off)
+{
+ struct mtk_led *led = container_of(cdev, struct mtk_led, cdev);
+ struct mtk_leds *leds = led->parent;
+ struct regmap *regmap = leds->hw->regmap;
+ u16 period;
+ u8 duty_cycle, duty_hw;
+
+ /* Units are in ms , if over the hardware able
+ * to support, fallback into software blink
+ */
+ if (*delay_on + *delay_off > MTK_MAX_PERIOD)
+ return -EINVAL;
+
+ /* LED subsystem requires a default user
+ * friendly blink pattern for the LED so using
+ * 1Hz duty cycle 50% here if without specific
+ * value delay_on and delay off being assigned
+ */
+ if (*delay_on == 0 && *delay_off == 0) {
+ *delay_on = 500;
+ *delay_off = 500;
+ }
+
+ period = *delay_on + *delay_off;
+
+ /* duty_cycle is the percentage of period during
+ * which the led is ON
+ */
+ duty_cycle = 100 * (*delay_on) / period;
+
+ mutex_lock(&leds->lock);
+
+ if (!led->current_brightness)
+ mtk_led_hw_on(cdev);
+
+ duty_hw = DIV_ROUND_CLOSEST(duty_cycle * 1000, 3125);
+ regmap_update_bits(regmap, MTK_MT6323_ISINK_CON0(led->id),
+ ISINK_DIM_DUTY_MASK, ISINK_DIM_DUTY(duty_hw));
+
+ regmap_update_bits(regmap, MTK_MT6323_ISINK_CON1(led->id),
+ ISINK_DIM_FSEL_MASK, ISINK_DIM_FSEL(period - 1));
+
+ mutex_unlock(&leds->lock);
+
+ dev_dbg(leds->dev, "%s: Hardware blink! period=%dms duty=%d for led%d\n",
+ __func__, period, duty_cycle, led->id);
+
+ return 0;
+}
+
+static int mtk_led_set_brightness(struct led_classdev *cdev,
+ enum led_brightness brightness)
+{
+ struct mtk_led *led = container_of(cdev, struct mtk_led, cdev);
+ struct mtk_leds *leds = led->parent;
+ struct regmap *regmap = leds->hw->regmap;
+
+ mutex_lock(&leds->lock);
+
+ if (!led->current_brightness && brightness)
+ mtk_led_hw_on(cdev);
+
+ if (brightness) {
+ /* Setup current output for the corresponding
+ * brightness level
+ */
+ regmap_update_bits(regmap, MTK_MT6323_ISINK_CON2(led->id),
+ ISINK_CH_STEP_MASK,
+ ISINK_CH_STEP(brightness - 1));
+
+ regmap_update_bits(regmap, MTK_MT6323_ISINK_CON2(led->id),
+ ISINK_SFSTR0_TC_MASK | ISINK_SFSTR0_EN_MASK,
+ ISINK_SFSTR0_TC(2) | ISINK_SFSTR0_EN);
+
+ dev_dbg(leds->dev, "Update led brightness:%d\n",
+ brightness);
+ }
+
+ if (!brightness)
+ mtk_led_hw_off(cdev);
+ led->current_brightness = brightness;
+
+ mutex_unlock(&leds->lock);
+
+ return 0;
+}
+
+static int mt6323_led_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = pdev->dev.of_node;
+ struct device_node *child;
+ struct mt6397_chip *hw = dev_get_drvdata(pdev->dev.parent);
+ struct mtk_leds *leds;
+ int ret, i = 0, count;
+ const char *state;
+ unsigned int status;
+
+ count = of_get_child_count(np);
+ if (!count)
+ return -ENODEV;
+
+ /* The number the LEDs on MT6323 could be support is
+ * up to MTK_MAX_DEVICES
+ */
+ count = (count <= MTK_MAX_DEVICES) ? count : MTK_MAX_DEVICES;
+
+ leds = devm_kzalloc(dev, sizeof(struct mtk_leds) +
+ sizeof(struct mtk_led) * count,
+ GFP_KERNEL);
+ if (!leds)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, leds);
+ leds->dev = dev;
+
+ /* leds->hw points to the underlying bus for the register
+ * controlled
+ */
+ leds->hw = hw;
+ mutex_init(&leds->lock);
+ leds->led_num = count;
+
+ status = RG_DRV_32K_CK_PDN;
+ regmap_update_bits(leds->hw->regmap, MTK_MT6323_TOP_CKPDN0,
+ RG_DRV_32K_CK_PDN_MASK, ~status);
+
+ /* Waiting for 32K stable prior to give the default value
+ * to each LED state decided through these useful common
+ * propertys such as label, linux,default-trigger and
+ * default-state
+ */
+ usleep_range(300, 500);
+
+ for_each_available_child_of_node(np, child) {
+ leds->led[i].cdev.name =
+ of_get_property(child, "label", NULL) ? :
+ child->name;
+ leds->led[i].cdev.default_trigger = of_get_property(child,
+ "linux,default-trigger",
+ NULL);
+ leds->led[i].cdev.max_brightness = MTK_MAX_BRIGHTNESS;
+ leds->led[i].cdev.brightness_set_blocking =
+ mtk_led_set_brightness;
+ leds->led[i].cdev.blink_set = mtk_led_set_blink;
+ leds->led[i].id = i;
+ leds->led[i].parent = leds;
+ state = of_get_property(child, "default-state", NULL);
+ if (state) {
+ if (!strcmp(state, "keep")) {
+ leds->led[i].current_brightness =
+ get_mtk_led_hw_brightness(&leds->led[i].cdev);
+ } else if (!strcmp(state, "on")) {
+ mtk_led_set_brightness(&leds->led[i].cdev, 1);
+ } else {
+ mtk_led_set_brightness(&leds->led[i].cdev,
+ 0);
+ }
+ }
+ ret = devm_led_classdev_register(dev, &leds->led[i].cdev);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to register LED: %d\n",
+ ret);
+ return ret;
+ }
+ leds->led[i].cdev.dev->of_node = child;
+ i++;
+ }
+
+ return 0;
+}
+
+static int mt6323_led_remove(struct platform_device *pdev)
+{
+ struct mtk_leds *leds = platform_get_drvdata(pdev);
+ int i;
+
+ /* Turned the LED to OFF state if driver removal */
+ for (i = 0 ; i < leds->led_num ; i++)
+ mtk_led_hw_off(&leds->led[i].cdev);
+
+ regmap_update_bits(leds->hw->regmap, MTK_MT6323_TOP_CKPDN0,
+ RG_DRV_32K_CK_PDN_MASK, RG_DRV_32K_CK_PDN);
+ return 0;
+}
+
+static const struct of_device_id mt6323_led_dt_match[] = {
+ { .compatible = "mediatek,mt6323-led" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, mt6323_led_dt_match);
+
+static struct platform_driver mt6323_led_driver = {
+ .probe = mt6323_led_probe,
+ .remove = mt6323_led_remove,
+ .driver = {
+ .name = "mt6323-led",
+ .of_match_table = mt6323_led_dt_match,
+ },
+};
+
+module_platform_driver(mt6323_led_driver);
+
+MODULE_DESCRIPTION("LED driver for Mediatek MT6323 PMIC");
+MODULE_AUTHOR("Sean Wang <sean.wang@xxxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
--
1.9.1