Re: [PATCH v4 3/4] leds: Add LED support for MT6323 PMIC

Jacek Anaszewski
2017-02-26T18:30:51Z

Hi Sean,

Thanks for the update. I have one comment to your changes below.

On 02/24/2017 07:47 PM, sean.wang@mediatek.com wrote:
> From: Sean Wang <sean.wang@mediatek.com>
>
> MT6323 PMIC is a multi-function device that includes
> LED function. It allows attaching up to 4 LEDs which
> can either be on, off or dimmed and/or blinked with
> the controller.
>
> Signed-off-by: Sean Wang <sean.wang@mediatek.com>
> ---
> drivers/leds/Kconfig | 8 +
> drivers/leds/Makefile | 1 +
> drivers/leds/leds-mt6323.c | 500 +++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 509 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..7274581
> --- /dev/null
> +++ b/drivers/leds/leds-mt6323.c
> @@ -0,0 +1,500 @@
> +/*
> + * LED driver for Mediatek MT6323 PMIC
> + *
> + * Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com>
> + *
> + * 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/leds.h>
> +#include <linux/mfd/mt6323/registers.h>
> +#include <linux/mfd/mt6397/core.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +/*
> + * Register field for MT6323_TOP_CKPDN0 to enable
> + * 32K clock common for LED device.
> + */
> +#define MT6323_RG_DRV_32K_CK_PDN BIT(11)
> +#define MT6323_RG_DRV_32K_CK_PDN_MASK BIT(11)
> +
> +/*
> + * Register field for MT6323_TOP_CKPDN2 to enable
> + * individual clock for LED device.
> + */
> +#define MT6323_RG_ISINK_CK_PDN(i) BIT(i)
> +#define MT6323_RG_ISINK_CK_PDN_MASK(i) BIT(i)
> +
> +/*
> + * Register field for MT6323_TOP_CKCON1 to select
> + * clock source.
> + */
> +#define MT6323_RG_ISINK_CK_SEL_MASK(i) (BIT(10) << (i))
> +
> +/*
> + * Register for MT6323_ISINK_CON0 to setup the
> + * duty cycle of the blink.
> + */
> +#define MT6323_ISINK_CON0(i) (MT6323_ISINK0_CON0 + 0x8 * (i))
> +#define MT6323_ISINK_DIM_DUTY_MASK (0x1f << 8)
> +#define MT6323_ISINK_DIM_DUTY(i) (((i) << 8) & \
> + MT6323_ISINK_DIM_DUTY_MASK)
> +
> +/* Register to setup the period of the blink. */
> +#define MT6323_ISINK_CON1(i) (MT6323_ISINK0_CON1 + 0x8 * (i))
> +#define MT6323_ISINK_DIM_FSEL_MASK (0xffff)
> +#define MT6323_ISINK_DIM_FSEL(i) ((i) & MT6323_ISINK_DIM_FSEL_MASK)
> +
> +/* Register to control the brightness. */
> +#define MT6323_ISINK_CON2(i) (MT6323_ISINK0_CON2 + 0x8 * (i))
> +#define MT6323_ISINK_CH_STEP_SHIFT 12
> +#define MT6323_ISINK_CH_STEP_MASK (0x7 << 12)
> +#define MT6323_ISINK_CH_STEP(i) (((i) << 12) & \
> + MT6323_ISINK_CH_STEP_MASK)
> +#define MT6323_ISINK_SFSTR0_TC_MASK (0x3 << 1)
> +#define MT6323_ISINK_SFSTR0_TC(i) (((i) << 1) & \
> + MT6323_ISINK_SFSTR0_TC_MASK)
> +#define MT6323_ISINK_SFSTR0_EN_MASK BIT(0)
> +#define MT6323_ISINK_SFSTR0_EN BIT(0)
> +
> +/* Register to LED channel enablement. */
> +#define MT6323_ISINK_CH_EN_MASK(i) BIT(i)
> +#define MT6323_ISINK_CH_EN(i) BIT(i)
> +
> +#define MT6323_MAX_PERIOD 10000
> +#define MT6323_MAX_LEDS 4
> +#define MT6323_MAX_BRIGHTNESS 6
> +#define MT6323_UNIT_DUTY 3125
> +
> +struct mt6323_leds;
> +
> +/**
> + * struct mt6323_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 mt6323_led {
> + int id;
> + struct mt6323_leds *parent;
> + struct led_classdev cdev;
> + enum led_brightness current_brightness;
> +};
> +
> +/**
> + * struct mt6323_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
> + * @lock: the lock among process context
> + * @led: the array that contains the state of individual
> + * LED device
> + */
> +struct mt6323_leds {
> + struct device *dev;
> + struct mt6397_chip *hw;
> + /* protect among process context */
> + struct mutex lock;
> + struct mt6323_led *led[MT6323_MAX_LEDS];
> +};
> +
> +static int mt6323_led_hw_brightness(struct led_classdev *cdev,
> + enum led_brightness brightness)
> +{
> + struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
> + struct mt6323_leds *leds = led->parent;
> + struct regmap *regmap = leds->hw->regmap;
> + u32 con2_mask = 0, con2_val = 0;
> + int ret;
> +
> + /*
> + * Setup current output for the corresponding
> + * brightness level.
> + */
> + con2_mask |= MT6323_ISINK_CH_STEP_MASK |
> + MT6323_ISINK_SFSTR0_TC_MASK |
> + MT6323_ISINK_SFSTR0_EN_MASK;
> + con2_val |= MT6323_ISINK_CH_STEP(brightness - 1) |
> + MT6323_ISINK_SFSTR0_TC(2) |
> + MT6323_ISINK_SFSTR0_EN;
> +
> + ret = regmap_update_bits(regmap, MT6323_ISINK_CON2(led->id),
> + con2_mask, con2_val);
> + return ret;
> +}
> +
> +static int mt6323_led_hw_off(struct led_classdev *cdev)
> +{
> + struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
> + struct mt6323_leds *leds = led->parent;
> + struct regmap *regmap = leds->hw->regmap;
> + unsigned int status;
> + int ret;
> +
> + status = MT6323_ISINK_CH_EN(led->id);
> + ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL,
> + MT6323_ISINK_CH_EN_MASK(led->id), ~status);
> + if (ret < 0)
> + return ret;
> +
> + usleep_range(100, 300);
> + ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2,
> + MT6323_RG_ISINK_CK_PDN_MASK(led->id),
> + MT6323_RG_ISINK_CK_PDN(led->id));
> + if (ret < 0)
> + return ret;
> +
> + return 0;
> +}
> +
> +static enum led_brightness
> +mt6323_get_led_hw_brightness(struct led_classdev *cdev)
> +{
> + struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
> + struct mt6323_leds *leds = led->parent;
> + struct regmap *regmap = leds->hw->regmap;
> + unsigned int status;
> + int ret;
> +
> + ret = regmap_read(regmap, MT6323_TOP_CKPDN2, &status);
> + if (ret < 0)
> + return ret;
> +
> + if (status & MT6323_RG_ISINK_CK_PDN_MASK(led->id))
> + return 0;
> +
> + ret = regmap_read(regmap, MT6323_ISINK_EN_CTRL, &status);
> + if (ret < 0)
> + return ret;
> +
> + if (!(status & MT6323_ISINK_CH_EN(led->id)))
> + return 0;
> +
> + ret = regmap_read(regmap, MT6323_ISINK_CON2(led->id), &status);
> + if (ret < 0)
> + return ret;
> +
> + return ((status & MT6323_ISINK_CH_STEP_MASK)
> + >> MT6323_ISINK_CH_STEP_SHIFT) + 1;
> +}
> +
> +static int mt6323_led_hw_on(struct led_classdev *cdev,
> + enum led_brightness brightness)
> +{
> + struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
> + struct mt6323_leds *leds = led->parent;
> + struct regmap *regmap = leds->hw->regmap;
> + unsigned int status;
> + int ret;
> +
> + /*
> + * Setup required clock source, enable the corresponding
> + * clock and channel and let work with continuous blink as
> + * the default.
> + */
> + ret = regmap_update_bits(regmap, MT6323_TOP_CKCON1,
> + MT6323_RG_ISINK_CK_SEL_MASK(led->id), 0);
> + if (ret < 0)
> + return ret;
> +
> + status = MT6323_RG_ISINK_CK_PDN(led->id);
> + ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2,
> + MT6323_RG_ISINK_CK_PDN_MASK(led->id),
> + ~status);
> + if (ret < 0)
> + return ret;
> +
> + usleep_range(100, 300);
> +
> + ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL,
> + MT6323_ISINK_CH_EN_MASK(led->id),
> + MT6323_ISINK_CH_EN(led->id));
> + if (ret < 0)
> + return ret;
> +
> + ret = mt6323_led_hw_brightness(cdev, brightness);
> + if (ret < 0)
> + return ret;
> +
> + ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id),
> + MT6323_ISINK_DIM_DUTY_MASK,
> + MT6323_ISINK_DIM_DUTY(31));
> + if (ret < 0)
> + return ret;
> +
> + ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id),
> + MT6323_ISINK_DIM_FSEL_MASK,
> + MT6323_ISINK_DIM_FSEL(1000));
> + if (ret < 0)
> + return ret;
> +
> + return 0;
> +}
> +
> +static int mt6323_led_set_blink(struct led_classdev *cdev,
> + unsigned long *delay_on,
> + unsigned long *delay_off)
> +{
> + struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
> + struct mt6323_leds *leds = led->parent;
> + struct regmap *regmap = leds->hw->regmap;
> + u16 period;
> + u8 duty_cycle, duty_hw;
> + int ret;
> +
> + /*
> + * Units are in ms, if over the hardware able
> + * to support, fallback into software blink
> + */
> + if (*delay_on + *delay_off > MT6323_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 && !*delay_off) {
> + *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;
> +
> + /* hardware doesn't support zero duty cycle. */
> + if (!duty_cycle)
> + return -EINVAL;
> +
> + mutex_lock(&leds->lock);
> + /*
> + * Set max_brightness as the software blink behavior
> + * when no blink brightness.
> + */
> + if (!led->current_brightness) {
> + ret = mt6323_led_hw_on(cdev, cdev->max_brightness);
> + if (ret < 0)
> + goto out;
> + led->current_brightness = cdev->max_brightness;
> + }
> +
> + duty_hw = DIV_ROUND_CLOSEST(duty_cycle * 1000, MT6323_UNIT_DUTY);
> + ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id),
> + MT6323_ISINK_DIM_DUTY_MASK,
> + MT6323_ISINK_DIM_DUTY(duty_hw - 1));
> + if (ret < 0)
> + goto out;
> +
> + ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id),
> + MT6323_ISINK_DIM_FSEL_MASK,
> + MT6323_ISINK_DIM_FSEL(period - 1));
> +out:
> + mutex_unlock(&leds->lock);
> +
> + return ret;
> +}
> +
> +static int mt6323_led_set_brightness(struct led_classdev *cdev,
> + enum led_brightness brightness)
> +{
> + struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
> + struct mt6323_leds *leds = led->parent;
> + int ret;
> +
> + mutex_lock(&leds->lock);
> +
> + if (!led->current_brightness && brightness) {
> + ret = mt6323_led_hw_on(cdev, brightness);
> + if (ret < 0)
> + goto out;
> + } else if (brightness) {
> + ret = mt6323_led_hw_brightness(cdev, brightness);
> + if (ret < 0)
> + goto out;
> + } else {
> + ret = mt6323_led_hw_off(cdev);
> + if (ret < 0)
> + goto out;
> + }
> +
> + led->current_brightness = brightness;
> +out:
> + mutex_unlock(&leds->lock);
> +
> + return ret;
> +}
> +
> +static int mt6323_led_set_dt_default(struct led_classdev *cdev,
> + struct device_node *np)
> +{
> + struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
> + const char *state;
> + int ret = 0;
> +
> + led->cdev.name = of_get_property(np, "label", NULL) ? : np->name;
> + led->cdev.default_trigger = of_get_property(np,
> + "linux,default-trigger",
> + NULL);
> +
> + state = of_get_property(np, "default-state", NULL);
> + if (state) {
> + if (!strcmp(state, "keep")) {
> + ret = mt6323_get_led_hw_brightness(cdev);
> + if (ret < 0)
> + return ret;
> + led->current_brightness = ret;
> + ret = 0;
> + } else if (!strcmp(state, "on")) {
> + ret =
> + mt6323_led_set_brightness(cdev, cdev->max_brightness);
> + } else {
> + ret = mt6323_led_set_brightness(cdev, LED_OFF);
> + }
> + }
> +
> + return ret;
> +}
> +
> +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 mt6323_leds *leds;
> + struct mt6323_led *led;
> + int ret;
> + unsigned int status;
> + u32 reg;
> +
> + leds = devm_kzalloc(dev, sizeof(*leds), 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);
> +
> + status = MT6323_RG_DRV_32K_CK_PDN;
> + ret = regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
> + MT6323_RG_DRV_32K_CK_PDN_MASK, ~status);
> + if (ret < 0) {
> + dev_err(leds->dev,
> + "Failed to update MT6323_TOP_CKPDN0 Register\n");
> + return ret;
> + }
> +
> + for_each_available_child_of_node(np, child) {
> + ret = of_property_read_u32(child, "reg", &reg);
> + if (ret) {
> + dev_err(dev, "Failed to read led 'reg' property\n");
> + goto put_child_node;
> + }
> +
> + if (reg < 0 || reg > MT6323_MAX_LEDS || leds->led[reg]) {
> + dev_err(dev, "Invalid led reg %u\n", reg);
> + ret = -EINVAL;
> + goto put_child_node;
> + }
> +
> + led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
> + if (!led) {
> + ret = -ENOMEM;
> + goto put_child_node;
> + }
> +
> + leds->led[reg] = led;
> + leds->led[reg]->id = reg;
> + leds->led[reg]->cdev.max_brightness = MT6323_MAX_BRIGHTNESS;
> + leds->led[reg]->cdev.brightness_set_blocking =
> + mt6323_led_set_brightness;
> + leds->led[reg]->cdev.blink_set = mt6323_led_set_blink;
> + leds->led[reg]->cdev.brightness_get =
> + mt6323_get_led_hw_brightness;
> + leds->led[reg]->parent = leds;
> +
> + ret = mt6323_led_set_dt_default(&leds->led[reg]->cdev, child);
> + if (ret < 0) {
> + dev_err(leds->dev,
> + "Failed to LED set default from devicetree\n");
> + return ret;

Here you also need "goto put_child_node;".

> + }
> +
> + ret = devm_led_classdev_register(dev, &leds->led[reg]->cdev);
> + if (ret) {
> + dev_err(&pdev->dev, "Failed to register LED: %d\n",
> + ret);
> + return ret;

Ditto.

> + }
> + leds->led[reg]->cdev.dev->of_node = child;
> + }
> +
> + return 0;
> +
> +put_child_node:
> + of_node_put(child);
> + return ret;
> +}
> +
> +static int mt6323_led_remove(struct platform_device *pdev)
> +{
> + struct mt6323_leds *leds = platform_get_drvdata(pdev);
> + int i;
> +
> + /* Turn the LEDs off on driver removal. */
> + for (i = 0 ; leds->led[i] ; i++)
> + mt6323_led_hw_off(&leds->led[i]->cdev);
> +
> + regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
> + MT6323_RG_DRV_32K_CK_PDN_MASK,
> + MT6323_RG_DRV_32K_CK_PDN);
> +
> + mutex_destroy(&leds->lock);
> +
> + 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@mediatek.com>");
> +MODULE_LICENSE("GPL");
>

--
Best regards,
Jacek Anaszewski