Re: [PATCH 2/4] leds: axp20x: Support charger LED on AXP20x like PMICs

From: Dan Murphy
Date: Tue Feb 25 2020 - 07:59:59 EST

Ondrej

On 2/23/20 7:14 AM, Ondrej Jirman wrote:
There is single LED that can be turned on and off by the user, or set to
be controlled by the charger in 2 different modes.

The driver initializes the LED to be controlled by the charger, but
allows to switch it to user control, and change the mode of charging
indication via a sysfs.

The driver was developed on AXP813, but should work on other PMICs like
that without changes.

Signed-off-by: Ondrej Jirman <megous@xxxxxxxxxx>
---
drivers/leds/Kconfig | 7 ++
drivers/leds/Makefile | 1 +
drivers/leds/leds-axp20x.c | 240 +++++++++++++++++++++++++++++++++++++
drivers/mfd/axp20x.c | 3 +
4 files changed, 251 insertions(+)
create mode 100644 drivers/leds/leds-axp20x.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index d82f1dea37111..80a3f31f6f4c3 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -846,6 +846,13 @@ config LEDS_TPS6105X
It is a single boost converter primarily for white LEDs and
audio amplifiers.
+config LEDS_AXP20X
+ tristate "Charger LED support for AXP20X-like PMICs (AXP813, ...)"
+ depends on LEDS_CLASS && MFD_AXP20X
+ help
+ This option enables support for on-chip LED driver on
+ AXP20X-like PMICs.
+
comment "LED Triggers"
source "drivers/leds/trigger/Kconfig"
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index d7e1107753fb1..80ea1bc4744b0 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -86,6 +86,7 @@ obj-$(CONFIG_LEDS_TI_LMU_COMMON) += leds-ti-lmu-common.o
obj-$(CONFIG_LEDS_LM3697) += leds-lm3697.o
obj-$(CONFIG_LEDS_LM36274) += leds-lm36274.o
obj-$(CONFIG_LEDS_TPS6105X) += leds-tps6105x.o
+obj-$(CONFIG_LEDS_AXP20X) += leds-axp20x.o
# LED SPI Drivers
obj-$(CONFIG_LEDS_CR0014114) += leds-cr0014114.o
diff --git a/drivers/leds/leds-axp20x.c b/drivers/leds/leds-axp20x.c
new file mode 100644
index 0000000000000..e6c9853b84d52
--- /dev/null
+++ b/drivers/leds/leds-axp20x.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * LED Driver for X-Powers AXP813 PMIC and similar.
+ *
+ * Copyright(c) 2020 Ondrej Jirman <megous@xxxxxxxxxx>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/leds.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/mfd/axp20x.h>
+
+#define AXP20X_CHGLED_CTRL_MASK BIT(3)
+#define AXP20X_CHGLED_CTRL_CHARGER BIT(3)
+#define AXP20X_CHGLED_CTRL_USER 0
+
+#define AXP20X_CHRG_CTRL2_MODE BIT(4)
+
+#define AXP20X_CHGLED_USER_STATE_MASK GENMASK(5, 4)
+#define AXP20X_CHGLED_USER_STATE_OFF (0 << 4)
+#define AXP20X_CHGLED_USER_STATE_BLINK_SLOW (1 << 4)
+#define AXP20X_CHGLED_USER_STATE_BLINK_FAST (2 << 4)
+#define AXP20X_CHGLED_USER_STATE_ON (3 << 4)
+
+struct axp20x_led {
+ struct led_classdev cdev;
+ struct regmap *regmap;
+};
+
+static int axp20x_led_set(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ struct axp20x_led *led =
+ container_of(led_cdev, struct axp20x_led, cdev);
+ unsigned int val;
+
+ val = value == LED_OFF ? AXP20X_CHGLED_USER_STATE_OFF :
+ AXP20X_CHGLED_USER_STATE_ON;
+
+ return regmap_update_bits(led->regmap, AXP20X_OFF_CTRL,
+ AXP20X_CHGLED_USER_STATE_MASK, val);
+
+}
+
+static ssize_t charger_control_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct axp20x_led *led =
+ container_of(led_cdev, struct axp20x_led, cdev);
+ unsigned int val;
+ int ret;
+
+ ret = regmap_read(led->regmap, AXP20X_OFF_CTRL, &val);
+ if (ret)
+ return ret;
+
+ return scnprintf(buf, PAGE_SIZE, "%u\n",
+ val & AXP20X_CHGLED_CTRL_MASK ? 1 : 0);
+}
+
+static ssize_t charger_control_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct axp20x_led *led =
+ container_of(led_cdev, struct axp20x_led, cdev);
+ bool status;
+ int ret;
+
+ ret = kstrtobool(buf, &status);
+ if (ret)
+ return ret;
+
+ ret = regmap_update_bits(led->regmap, AXP20X_OFF_CTRL,
+ AXP20X_CHGLED_CTRL_MASK,
+ status ? AXP20X_CHGLED_CTRL_CHARGER :
+ AXP20X_CHGLED_CTRL_USER);
+ if (ret)
+ return ret;
+
+ return len;
+}
+
+static ssize_t charger_mode_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct axp20x_led *led =
+ container_of(led_cdev, struct axp20x_led, cdev);
+ unsigned int val;
+ int ret;
+
+ ret = regmap_read(led->regmap, AXP20X_CHRG_CTRL2, &val);
+ if (ret)
+ return ret;
+
+ return scnprintf(buf, PAGE_SIZE, "%u\n",
+ val & AXP20X_CHRG_CTRL2_MODE ? 1 : 0);
+}
+
+static ssize_t charger_mode_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct axp20x_led *led =
+ container_of(led_cdev, struct axp20x_led, cdev);
+ unsigned int mode;
+ int ret;
+
+ ret = kstrtouint(buf, 0, &mode);
+ if (ret)
+ return ret;
+
+ if (mode > 1)
+ return -ERANGE;
+
+ ret = regmap_update_bits(led->regmap, AXP20X_CHRG_CTRL2,
+ AXP20X_CHRG_CTRL2_MODE,
+ mode ? AXP20X_CHRG_CTRL2_MODE : 0);
+ if (ret)
+ return ret;
+
+ return len;
+}
+
+static DEVICE_ATTR_RW(charger_control);
+static DEVICE_ATTR_RW(charger_mode);
+
+static struct attribute *axp20x_led_attrs[] = {
+ &dev_attr_charger_control.attr,
+ &dev_attr_charger_mode.attr,
+ NULL,
+};
+
+ATTRIBUTE_GROUPS(axp20x_led);
+
+static int axp20x_led_probe(struct platform_device *pdev)
+{
+ struct axp20x_dev *axp20x;
+ struct axp20x_led *led;
+ int ret;
+
+ if (!of_device_is_available(pdev->dev.of_node))
+ return -ENODEV;
+
+ axp20x = dev_get_drvdata(pdev->dev.parent);
+ if (!axp20x)
+ return -EINVAL;
+
+ led = devm_kzalloc(&pdev->dev,
+ sizeof(struct axp20x_led),
+ GFP_KERNEL);
+ if (!led)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, led);
+
+ led->regmap = axp20x->regmap;
+
+ led->cdev.name = "axp20x-chgarger-led";


This does not follow the LED device naming convention please refer to the leds-class.rst document

https://elixir.bootlin.com/linux/latest/source/Documentation/leds/leds-class.rst

Dan