Re: [PATCH v2 11/13] leds: max77650: add LEDs support
From: Jacek Anaszewski
Date: Wed Jan 30 2019 - 14:59:59 EST
Hi Bartosz,
Thank you for the update.
One more thing drew my attention, please refer below.
On 1/29/19 2:35 PM, Bartosz Golaszewski wrote:
From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
This adds basic support for LEDs for the max77650 PMIC. The device has
three current sinks for driving LEDs.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
---
drivers/leds/Kconfig | 6 ++
drivers/leds/Makefile | 1 +
drivers/leds/leds-max77650.c | 152 +++++++++++++++++++++++++++++++++++
3 files changed, 159 insertions(+)
create mode 100644 drivers/leds/leds-max77650.c
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index a72f97fca57b..6e7a8f51eccc 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -608,6 +608,12 @@ config LEDS_TLC591XX
This option enables support for Texas Instruments TLC59108
and TLC59116 LED controllers.
+config LEDS_MAX77650
+ tristate "LED support for Maxim MAX77650 PMIC"
+ depends on MFD_MAX77650
+ help
+ LEDs driver for MAX77650 family of PMICs from Maxim Integrated."
+
config LEDS_MAX77693
tristate "LED support for MAX77693 Flash"
depends on LEDS_CLASS_FLASH
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 4c1b0054f379..f48b2404dbb7 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_LEDS_MC13783) += leds-mc13783.o
obj-$(CONFIG_LEDS_NS2) += leds-ns2.o
obj-$(CONFIG_LEDS_NETXBIG) += leds-netxbig.o
obj-$(CONFIG_LEDS_ASIC3) += leds-asic3.o
+obj-$(CONFIG_LEDS_MAX77650) += leds-max77650.o
obj-$(CONFIG_LEDS_MAX77693) += leds-max77693.o
obj-$(CONFIG_LEDS_MAX8997) += leds-max8997.o
obj-$(CONFIG_LEDS_LM355x) += leds-lm355x.o
diff --git a/drivers/leds/leds-max77650.c b/drivers/leds/leds-max77650.c
new file mode 100644
index 000000000000..e3a3c0e79b7a
--- /dev/null
+++ b/drivers/leds/leds-max77650.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (C) 2018 BayLibre SAS
+// Author: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
+//
+// LED driver for MAXIM 77650/77651 charger/power-supply.
+
+#include <linux/i2c.h>
+#include <linux/leds.h>
+#include <linux/mfd/max77650.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define MAX77650_NUM_LEDS 3
+
+#define MAX77650_LED_A_BASE 0x40
+#define MAX77650_LED_B_BASE 0x43
+
+#define MAX77650_LED_BR_MASK GENMASK(4, 0)
+#define MAX77650_LED_EN_MASK GENMASK(7, 6)
+
+/* Enable EN_LED_MSTR. */
+#define MAX77650_LED_TOP_DEFAULT BIT(0)
+
+#define MAX77650_LED_ENABLE GENMASK(7, 6)
+#define MAX77650_LED_DISABLE 0x00
+
+#define MAX77650_LED_A_DEFAULT MAX77650_LED_DISABLE
+/* 100% on duty */
+#define MAX77650_LED_B_DEFAULT GENMASK(3, 0)
+
+struct max77650_led {
+ struct led_classdev cdev;
+ struct regmap *map;
+ unsigned int regA;
+ unsigned int regB;
+};
+
+static struct max77650_led *max77650_to_led(struct led_classdev *cdev)
+{
+ return container_of(cdev, struct max77650_led, cdev);
+}
+
+static int max77650_led_brightness_set(struct led_classdev *cdev,
+ enum led_brightness brightness)
+{
+ struct max77650_led *led = max77650_to_led(cdev);
+ int val, mask;
+
+ mask = MAX77650_LED_BR_MASK | MAX77650_LED_EN_MASK;
+
+ if (brightness == LED_OFF) {
+ val = MAX77650_LED_DISABLE;
+ } else {
+ val = MAX77650_LED_ENABLE;
+ /*
+ * We can set the brightness with 5-bit resolution.
+ *
+ * For brightness == 1, the bits we're writing will be 0, but
+ * since we keep LED_FS0 set to 12.8mA full-scale range, the
+ * LED will be lit slightly.
+ */
+ val |= brightness / 8;
We have max_brightness property and you seem not to use it.
With 5-bit brightness resolution it should be initialized
to 32 and then we will be able to avoid the division here.
+ }
+
+ return regmap_update_bits(led->map, led->regA, mask, val);
+}
+
+static int max77650_led_probe(struct platform_device *pdev)
+{
+ struct device_node *of_node, *child;
+ struct max77650_led *leds, *led;
+ struct device *parent;
+ struct device *dev;
+ struct regmap *map;
+ const char *label;
+ int rv, num_leds;
+ u32 reg;
+
+ dev = &pdev->dev;
+ parent = dev->parent;
+ of_node = dev->of_node;
+
+ if (!of_node)
+ return -ENODEV;
+
+ leds = devm_kcalloc(dev, sizeof(*leds), MAX77650_NUM_LEDS, GFP_KERNEL);
+ if (!leds)
+ return -ENOMEM;
+
+ map = dev_get_regmap(dev->parent, NULL);
+ if (!map)
+ return -ENODEV;
+
+ num_leds = of_get_child_count(of_node);
+ if (!num_leds || num_leds > MAX77650_NUM_LEDS)
+ return -ENODEV;
+
+ for_each_child_of_node(of_node, child) {
+ rv = of_property_read_u32(child, "reg", ®);
+ if (rv || reg >= MAX77650_NUM_LEDS)
+ return -EINVAL;
+
+ led = &leds[reg];
+ led->map = map;
+ led->regA = MAX77650_LED_A_BASE + reg;
+ led->regB = MAX77650_LED_B_BASE + reg;
+ led->cdev.brightness_set_blocking = max77650_led_brightness_set;
+
+ label = of_get_property(child, "label", NULL);
+ if (!label) {
+ led->cdev.name = "max77650::";
+ } else {
+ led->cdev.name = devm_kasprintf(dev, GFP_KERNEL,
+ "max77650:%s", label);
+ if (!led->cdev.name)
+ return -ENOMEM;
+ }
+
+ of_property_read_string(child, "linux,default-trigger",
+ &led->cdev.default_trigger);
+
+ rv = devm_of_led_classdev_register(dev, child, &led->cdev);
+ if (rv)
+ return rv;
+
+ rv = regmap_write(map, led->regA, MAX77650_LED_A_DEFAULT);
+ if (rv)
+ return rv;
+
+ rv = regmap_write(map, led->regB, MAX77650_LED_B_DEFAULT);
+ if (rv)
+ return rv;
+ }
+
+ return regmap_write(map,
+ MAX77650_REG_CNFG_LED_TOP,
+ MAX77650_LED_TOP_DEFAULT);
+}
+
+static struct platform_driver max77650_led_driver = {
+ .driver = {
+ .name = "max77650-led",
+ },
+ .probe = max77650_led_probe,
+};
+module_platform_driver(max77650_led_driver);
+
+MODULE_DESCRIPTION("MAXIM 77650/77651 LED driver");
+MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
--
Best regards,
Jacek Anaszewski