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kernel/drivers/leds/leds-sc27xx-bltc.c
Baolin Wang 8dbac65f5c leds: sc27xx: Add pattern_set/clear interfaces for LED controller 
This patch implements the 'pattern_set'and 'pattern_clear'
interfaces to support SC27XX LED breathing mode.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Acked-by: Pavel Machek <pavel@ucw.c>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
2018-10-11 21:59:11 +02:00

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// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Spreadtrum Communications Inc.
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <uapi/linux/uleds.h>
/* PMIC global control register definition */
#define SC27XX_MODULE_EN0 0xc08
#define SC27XX_CLK_EN0 0xc18
#define SC27XX_RGB_CTRL 0xebc
#define SC27XX_BLTC_EN BIT(9)
#define SC27XX_RTC_EN BIT(7)
#define SC27XX_RGB_PD BIT(0)
/* Breathing light controller register definition */
#define SC27XX_LEDS_CTRL 0x00
#define SC27XX_LEDS_PRESCALE 0x04
#define SC27XX_LEDS_DUTY 0x08
#define SC27XX_LEDS_CURVE0 0x0c
#define SC27XX_LEDS_CURVE1 0x10
#define SC27XX_CTRL_SHIFT 4
#define SC27XX_LED_RUN BIT(0)
#define SC27XX_LED_TYPE BIT(1)
#define SC27XX_DUTY_SHIFT 8
#define SC27XX_DUTY_MASK GENMASK(15, 0)
#define SC27XX_MOD_MASK GENMASK(7, 0)
#define SC27XX_CURVE_SHIFT 8
#define SC27XX_CURVE_L_MASK GENMASK(7, 0)
#define SC27XX_CURVE_H_MASK GENMASK(15, 8)
#define SC27XX_LEDS_OFFSET 0x10
#define SC27XX_LEDS_MAX 3
#define SC27XX_LEDS_PATTERN_CNT 4
/* Stage duration step, in milliseconds */
#define SC27XX_LEDS_STEP 125
/* Minimum and maximum duration, in milliseconds */
#define SC27XX_DELTA_T_MIN SC27XX_LEDS_STEP
#define SC27XX_DELTA_T_MAX (SC27XX_LEDS_STEP * 255)
struct sc27xx_led {
char name[LED_MAX_NAME_SIZE];
struct led_classdev ldev;
struct sc27xx_led_priv *priv;
u8 line;
bool active;
};
struct sc27xx_led_priv {
struct sc27xx_led leds[SC27XX_LEDS_MAX];
struct regmap *regmap;
struct mutex lock;
u32 base;
};
#define to_sc27xx_led(ldev) \
container_of(ldev, struct sc27xx_led, ldev)
static int sc27xx_led_init(struct regmap *regmap)
{
int err;
err = regmap_update_bits(regmap, SC27XX_MODULE_EN0, SC27XX_BLTC_EN,
SC27XX_BLTC_EN);
if (err)
return err;
err = regmap_update_bits(regmap, SC27XX_CLK_EN0, SC27XX_RTC_EN,
SC27XX_RTC_EN);
if (err)
return err;
return regmap_update_bits(regmap, SC27XX_RGB_CTRL, SC27XX_RGB_PD, 0);
}
static u32 sc27xx_led_get_offset(struct sc27xx_led *leds)
{
return leds->priv->base + SC27XX_LEDS_OFFSET * leds->line;
}
static int sc27xx_led_enable(struct sc27xx_led *leds, enum led_brightness value)
{
u32 base = sc27xx_led_get_offset(leds);
u32 ctrl_base = leds->priv->base + SC27XX_LEDS_CTRL;
u8 ctrl_shift = SC27XX_CTRL_SHIFT * leds->line;
struct regmap *regmap = leds->priv->regmap;
int err;
err = regmap_update_bits(regmap, base + SC27XX_LEDS_DUTY,
SC27XX_DUTY_MASK,
(value << SC27XX_DUTY_SHIFT) |
SC27XX_MOD_MASK);
if (err)
return err;
return regmap_update_bits(regmap, ctrl_base,
(SC27XX_LED_RUN | SC27XX_LED_TYPE) << ctrl_shift,
(SC27XX_LED_RUN | SC27XX_LED_TYPE) << ctrl_shift);
}
static int sc27xx_led_disable(struct sc27xx_led *leds)
{
struct regmap *regmap = leds->priv->regmap;
u32 ctrl_base = leds->priv->base + SC27XX_LEDS_CTRL;
u8 ctrl_shift = SC27XX_CTRL_SHIFT * leds->line;
return regmap_update_bits(regmap, ctrl_base,
(SC27XX_LED_RUN | SC27XX_LED_TYPE) << ctrl_shift, 0);
}
static int sc27xx_led_set(struct led_classdev *ldev, enum led_brightness value)
{
struct sc27xx_led *leds = to_sc27xx_led(ldev);
int err;
mutex_lock(&leds->priv->lock);
if (value == LED_OFF)
err = sc27xx_led_disable(leds);
else
err = sc27xx_led_enable(leds, value);
mutex_unlock(&leds->priv->lock);
return err;
}
static void sc27xx_led_clamp_align_delta_t(u32 *delta_t)
{
u32 v, offset, t = *delta_t;
v = t + SC27XX_LEDS_STEP / 2;
v = clamp_t(u32, v, SC27XX_DELTA_T_MIN, SC27XX_DELTA_T_MAX);
offset = v - SC27XX_DELTA_T_MIN;
offset = SC27XX_LEDS_STEP * (offset / SC27XX_LEDS_STEP);
*delta_t = SC27XX_DELTA_T_MIN + offset;
}
static int sc27xx_led_pattern_clear(struct led_classdev *ldev)
{
struct sc27xx_led *leds = to_sc27xx_led(ldev);
struct regmap *regmap = leds->priv->regmap;
u32 base = sc27xx_led_get_offset(leds);
u32 ctrl_base = leds->priv->base + SC27XX_LEDS_CTRL;
u8 ctrl_shift = SC27XX_CTRL_SHIFT * leds->line;
int err;
mutex_lock(&leds->priv->lock);
/* Reset the rise, high, fall and low time to zero. */
regmap_write(regmap, base + SC27XX_LEDS_CURVE0, 0);
regmap_write(regmap, base + SC27XX_LEDS_CURVE1, 0);
err = regmap_update_bits(regmap, ctrl_base,
(SC27XX_LED_RUN | SC27XX_LED_TYPE) << ctrl_shift, 0);
ldev->brightness = LED_OFF;
mutex_unlock(&leds->priv->lock);
return err;
}
static int sc27xx_led_pattern_set(struct led_classdev *ldev,
struct led_pattern *pattern,
u32 len, int repeat)
{
struct sc27xx_led *leds = to_sc27xx_led(ldev);
u32 base = sc27xx_led_get_offset(leds);
u32 ctrl_base = leds->priv->base + SC27XX_LEDS_CTRL;
u8 ctrl_shift = SC27XX_CTRL_SHIFT * leds->line;
struct regmap *regmap = leds->priv->regmap;
int err;
/*
* Must contain 4 tuples to configure the rise time, high time, fall
* time and low time to enable the breathing mode.
*/
if (len != SC27XX_LEDS_PATTERN_CNT)
return -EINVAL;
mutex_lock(&leds->priv->lock);
sc27xx_led_clamp_align_delta_t(&pattern[0].delta_t);
err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE0,
SC27XX_CURVE_L_MASK,
pattern[0].delta_t / SC27XX_LEDS_STEP);
if (err)
goto out;
sc27xx_led_clamp_align_delta_t(&pattern[1].delta_t);
err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE1,
SC27XX_CURVE_L_MASK,
pattern[1].delta_t / SC27XX_LEDS_STEP);
if (err)
goto out;
sc27xx_led_clamp_align_delta_t(&pattern[2].delta_t);
err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE0,
SC27XX_CURVE_H_MASK,
(pattern[2].delta_t / SC27XX_LEDS_STEP) <<
SC27XX_CURVE_SHIFT);
if (err)
goto out;
sc27xx_led_clamp_align_delta_t(&pattern[3].delta_t);
err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE1,
SC27XX_CURVE_H_MASK,
(pattern[3].delta_t / SC27XX_LEDS_STEP) <<
SC27XX_CURVE_SHIFT);
if (err)
goto out;
err = regmap_update_bits(regmap, base + SC27XX_LEDS_DUTY,
SC27XX_DUTY_MASK,
(pattern[1].brightness << SC27XX_DUTY_SHIFT) |
SC27XX_MOD_MASK);
if (err)
goto out;
/* Enable the LED breathing mode */
err = regmap_update_bits(regmap, ctrl_base,
SC27XX_LED_RUN << ctrl_shift,
SC27XX_LED_RUN << ctrl_shift);
if (!err)
ldev->brightness = pattern[1].brightness;
out:
mutex_unlock(&leds->priv->lock);
return err;
}
static int sc27xx_led_register(struct device *dev, struct sc27xx_led_priv *priv)
{
int i, err;
err = sc27xx_led_init(priv->regmap);
if (err)
return err;
for (i = 0; i < SC27XX_LEDS_MAX; i++) {
struct sc27xx_led *led = &priv->leds[i];
if (!led->active)
continue;
led->line = i;
led->priv = priv;
led->ldev.name = led->name;
led->ldev.brightness_set_blocking = sc27xx_led_set;
led->ldev.pattern_set = sc27xx_led_pattern_set;
led->ldev.pattern_clear = sc27xx_led_pattern_clear;
led->ldev.default_trigger = "pattern";
err = devm_led_classdev_register(dev, &led->ldev);
if (err)
return err;
}
return 0;
}
static int sc27xx_led_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node, *child;
struct sc27xx_led_priv *priv;
const char *str;
u32 base, count, reg;
int err;
count = of_get_child_count(np);
if (!count || count > SC27XX_LEDS_MAX)
return -EINVAL;
err = of_property_read_u32(np, "reg", &base);
if (err) {
dev_err(dev, "fail to get reg of property\n");
return err;
}
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
platform_set_drvdata(pdev, priv);
mutex_init(&priv->lock);
priv->base = base;
priv->regmap = dev_get_regmap(dev->parent, NULL);
if (!priv->regmap) {
err = -ENODEV;
dev_err(dev, "failed to get regmap: %d\n", err);
return err;
}
for_each_child_of_node(np, child) {
err = of_property_read_u32(child, "reg", &reg);
if (err) {
of_node_put(child);
mutex_destroy(&priv->lock);
return err;
}
if (reg >= SC27XX_LEDS_MAX || priv->leds[reg].active) {
of_node_put(child);
mutex_destroy(&priv->lock);
return -EINVAL;
}
priv->leds[reg].active = true;
err = of_property_read_string(child, "label", &str);
if (err)
snprintf(priv->leds[reg].name, LED_MAX_NAME_SIZE,
"sc27xx::");
else
snprintf(priv->leds[reg].name, LED_MAX_NAME_SIZE,
"sc27xx:%s", str);
}
err = sc27xx_led_register(dev, priv);
if (err)
mutex_destroy(&priv->lock);
return err;
}
static int sc27xx_led_remove(struct platform_device *pdev)
{
struct sc27xx_led_priv *priv = platform_get_drvdata(pdev);
mutex_destroy(&priv->lock);
return 0;
}
static const struct of_device_id sc27xx_led_of_match[] = {
{ .compatible = "sprd,sc2731-bltc", },
{ }
};
MODULE_DEVICE_TABLE(of, sc27xx_led_of_match);
static struct platform_driver sc27xx_led_driver = {
.driver = {
.name = "sprd-bltc",
.of_match_table = sc27xx_led_of_match,
},
.probe = sc27xx_led_probe,
.remove = sc27xx_led_remove,
};
module_platform_driver(sc27xx_led_driver);
MODULE_DESCRIPTION("Spreadtrum SC27xx breathing light controller driver");
MODULE_AUTHOR("Xiaotong Lu <xiaotong.lu@spreadtrum.com>");
MODULE_AUTHOR("Baolin Wang <baolin.wang@linaro.org>");
MODULE_LICENSE("GPL v2");
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