Re: [PATCH v6 12/13] leds: flash: mt6370: Add MediaTek MT6370 flashlight support

From: AngeloGioacchino Del Regno
Date: Fri Jul 22 2022 - 06:48:57 EST


Il 22/07/22 12:24, ChiaEn Wu ha scritto:
From: Alice Chen <alice_chen@xxxxxxxxxxx>

The MediaTek MT6370 is a highly-integrated smart power management IC,
which includes a single cell Li-Ion/Li-Polymer switching battery
charger, a USB Type-C & Power Delivery (PD) controller, dual Flash
LED current sources, a RGB LED driver, a backlight WLED driver,
a display bias driver and a general LDO for portable devices.

The Flash LED in MT6370 has 2 channels and support torch/strobe mode.
Add the support of MT6370 FLASH LED.

Signed-off-by: Alice Chen <alice_chen@xxxxxxxxxxx>
---

v6
- Use 'GENMASK' instead of 'BIT'.
- Use dev_err_probe to decrease LOC.
- Use 'dev' variable to make probe function more clean.
- Refine the return of _mt6370_flash_brightness_set function.
- Refine the descriptions.
- Use mt6370_clamp() instead of clamp_align().
- Use device resource managed API for v4l2 flash_release.
---
drivers/leds/flash/Kconfig | 12 +
drivers/leds/flash/Makefile | 1 +
drivers/leds/flash/leds-mt6370-flash.c | 633 +++++++++++++++++++++++++++++++++
3 files changed, 646 insertions(+)
create mode 100644 drivers/leds/flash/leds-mt6370-flash.c

diff --git a/drivers/leds/flash/Kconfig b/drivers/leds/flash/Kconfig
index d3eb689..d5761ed 100644
--- a/drivers/leds/flash/Kconfig
+++ b/drivers/leds/flash/Kconfig
@@ -90,4 +90,16 @@ config LEDS_SGM3140
This option enables support for the SGM3140 500mA Buck/Boost Charge
Pump LED Driver.
+config LEDS_MT6370_FLASHLIGHT
+ tristate "Flash LED Support for MediaTek MT6370 PMIC"
+ depends on LEDS_CLASS
+ depends on MFD_MT6370
+ help
+ Support 2 channels and torch/strobe mode.
+ Say Y here to enable support for
+ MT6370_FLASH_LED device.
+
+ This driver can also be built as a module. If so, the module
+ will be called "leds-mt6370-flash".
+
endif # LEDS_CLASS_FLASH
diff --git a/drivers/leds/flash/Makefile b/drivers/leds/flash/Makefile
index 0acbddc..4c4c171 100644
--- a/drivers/leds/flash/Makefile
+++ b/drivers/leds/flash/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_LEDS_MAX77693) += leds-max77693.o
obj-$(CONFIG_LEDS_RT4505) += leds-rt4505.o
obj-$(CONFIG_LEDS_RT8515) += leds-rt8515.o
obj-$(CONFIG_LEDS_SGM3140) += leds-sgm3140.o
+obj-$(CONFIG_LEDS_MT6370_FLASHLIGHT) += leds-mt6370-flash.o
diff --git a/drivers/leds/flash/leds-mt6370-flash.c b/drivers/leds/flash/leds-mt6370-flash.c
new file mode 100644
index 0000000..fe439ee
--- /dev/null
+++ b/drivers/leds/flash/leds-mt6370-flash.c
@@ -0,0 +1,633 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2022 Richtek Technology Corp.
+ *
+ * Author: Alice Chen <alice_chen@xxxxxxxxxxx
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+#include <media/v4l2-flash-led-class.h>
+
+enum {
+ MT6370_LED_FLASH1,
+ MT6370_LED_FLASH2,
+ MT6370_MAX_LEDS
+};
+
+/* Virtual definition for multicolor */
+
+#define MT6370_REG_FLEDEN 0x17E
+#define MT6370_REG_STRBTO 0x173
+#define MT6370_REG_CHGSTAT2 0x1D1
+#define MT6370_REG_FLEDSTAT1 0x1D9
+#define MT6370_REG_FLEDISTRB(_id) (0x174 + 4 * _id)

Please fix the indentation.

+#define MT6370_REG_FLEDITOR(_id) (0x175 + 4 * _id)
+#define MT6370_ITORCH_MASK GENMASK(4, 0)
+#define MT6370_ISTROBE_MASK GENMASK(6, 0)
+#define MT6370_STRBTO_MASK GENMASK(6, 0)
+#define MT6370_TORCHEN_MASK BIT(3)

..snip..

+
+static int mt6370_init_flash_properties(struct mt6370_led *led,
+ struct led_init_data *init_data)
+{
+ struct led_classdev_flash *flash = &led->flash;
+ struct led_classdev *lcdev = &flash->led_cdev;
+ struct mt6370_priv *priv = led->priv;
+ struct led_flash_setting *s;
+ u32 sources[MT6370_MAX_LEDS];
+ u32 max_uA, val;
+ int i, ret, num;
+
+ num = fwnode_property_count_u32(init_data->fwnode, "led-sources");
+ if (num < 1 || num > MT6370_MAX_LEDS)
+ return dev_err_probe(priv->dev, -EINVAL,
+ "Not specified or wrong number of led-sources\n");
+
+ ret = fwnode_property_read_u32_array(init_data->fwnode, "led-sources", sources, num);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < num; i++) {
+ if (sources[i] >= MT6370_MAX_LEDS)
+ return -EINVAL;
+ if (priv->leds_active & BIT(sources[i]))
+ return -EINVAL;
+ priv->leds_active |= BIT(sources[i]);
+
+ }
+ led->led_no = (num == MT6370_MAX_LEDS) ? MT6370_LED_JOINT :
+ sources[0];
+
+ max_uA = (num == 2) ? MT6370_ITORCH_DOUBLE_MAX_UA : MT6370_ITORCH_MAX_UA;
+ ret = fwnode_property_read_u32(init_data->fwnode, "led-max-microamp", &val);
+ if (ret) {
+ dev_warn(priv->dev,
+ "Not specified led-max-microamp, config to the minimum\n");

This should be a dev_info() instead.

+ val = MT6370_ITORCH_MIN_UA;
+ } else {
+ val = mt6370_clamp(val, MT6370_ITORCH_MIN_UA, max_uA,
+ MT6370_ITORCH_STEP_UA);
+ }
+
+ lcdev->max_brightness = (val - MT6370_ITORCH_MIN_UA) /
+ MT6370_ITORCH_STEP_UA + 1;
+ lcdev->brightness_set_blocking = mt6370_torch_brightness_set;
+ lcdev->flags |= LED_DEV_CAP_FLASH;
+
+ max_uA = (num == 2) ? MT6370_ISTRB_DOUBLE_MAX_UA : MT6370_ISTRB_MAX_UA;
+ ret = fwnode_property_read_u32(init_data->fwnode, "flash-max-microamp", &val);
+ if (ret) {
+ dev_warn(priv->dev,
+ "Not specified flash-max-microamp, config to the minimum\n");

same here

+ val = MT6370_ISTRB_MIN_UA;
+ } else {
+ val = mt6370_clamp(val, MT6370_ISTRB_MIN_UA, max_uA,
+ MT6370_ISTRB_STEP_UA);
+ }
+
+ s = &flash->brightness;
+ s->min = MT6370_ISTRB_MIN_UA;
+ s->step = MT6370_ISTRB_STEP_UA;
+ s->val = s->max = val;
+
+ /*
+ * Always configure as min level when off to
+ * prevent flash current spike
+ */
+ ret = _mt6370_flash_brightness_set(flash, s->min);
+ if (ret)
+ return ret;
+
+ ret = fwnode_property_read_u32(init_data->fwnode,
+ "flash-max-timeout-us", &val);
+ if (ret) {
+ dev_warn(priv->dev,
+ "Not specified flash-max-timeout-us, config to the minimum\n");

and same here

+ val = MT6370_STRBTO_MIN_US;
+ } else {
+ val = mt6370_clamp(val, MT6370_STRBTO_MIN_US,
+ MT6370_STRBTO_MAX_US, MT6370_STRBTO_STEP_US);
+ }
+
+ s = &flash->timeout;
+ s->min = MT6370_STRBTO_MIN_US;
+ s->step = MT6370_STRBTO_STEP_US;
+ s->val = s->max = val;
+
+ flash->ops = &mt6370_flash_ops;
+
+ return 0;
+}
+
+static int mt6370_init_common_properties(struct mt6370_led *led,
+ struct led_init_data *init_data)
+{
+ const char * const states[] = { "off", "keep", "on" };
+ const char *str = states[STATE_OFF];
+ int ret;
+
+ fwnode_property_read_string(init_data->fwnode, "default-state", &str);
+ ret = match_string(states, ARRAY_SIZE(states), str);
+ if (ret >= 0)
+ led->default_state = ret;
+
+ return 0;
+}
+
+static int mt6370_led_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mt6370_priv *priv;
+ struct fwnode_handle *child;
+ size_t count;
+ int i = 0, ret;
+
+ count = device_get_child_node_count(dev);
+ if (!count || count > MT6370_MAX_LEDS)
+ return dev_err_probe(dev, -EINVAL,
+ "No child node or node count over max led number %zu\n", count);
+
+ priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->leds_count = count;
+ priv->dev = dev;
+ mutex_init(&priv->lock);
+
+ priv->regmap = dev_get_regmap(dev->parent, NULL);
+ if (!priv->regmap)
+ return dev_err_probe(dev, -ENODEV, "Failed to get parent regmap\n");
+
+ device_for_each_child_node(dev, child) {
+ struct mt6370_led *led = priv->leds + i;
+ struct led_init_data init_data = { .fwnode = child, };
+
+ led->priv = priv;
+ ret = mt6370_init_common_properties(led, &init_data);
+ if (ret)
+ return ret;
+
+ ret = mt6370_init_flash_properties(led, &init_data);
+

Unnecessary blank line here.

+ if (ret)
+ return ret;
+
+ ret = mt6370_led_register(dev, led, &init_data);
+ if (ret)
+ return ret;
+
+ i++;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id mt6370_led_of_id[] = {
+ { .compatible = "mediatek,mt6370-flashlight" },

As common practice, write that the last element is a sentinel.

{ /* sentinel */ },


Everything else looks good.

Regards,
Angelo