Re: [PATCH v4 1/2] leds: flash: add driver to support flash LED module in QCOM PMICs

From: Fenglin Wu
Date: Tue Nov 01 2022 - 01:10:33 EST




On 2022/10/31 18:34, Dylan Van Assche wrote:

Hi Fenglin,

Thanks for submitting these patches! They are really nice!
I tested these patches on an SDM845 based device as the downstream
driver is the same for the PMI8998 compared to the mentioned PMICs in
this patchseries.

Tested-by: Dylan Van Assche <me@xxxxxxxxxxxxxxxxx> # sdm845-shift-
axolotl + pmi8998

Thanks for testing the patch at your side, Dylan!

Add initial driver to support flash LED module found in Qualcomm
Technologies, Inc. PMICs. The flash module can have 3 or 4 channels
and each channel can be controlled indepedently and support full >
scale
current up to 1.5 A. It also supports connecting two channels >
together
to supply one LED component with full scale current up to 2 A. In >
that
case, the current will be split on each channel symmetrically and
the
channels will be enabled and disabled at the same time.

Signed-off-by: Fenglin Wu <quic_fenglinw@xxxxxxxxxxx>
Tested-by: Luca Weiss <luca.weiss@xxxxxxxxxxxxx> # > sm7225-
fairphone-fp4 + pm6150l
---
 drivers/leds/flash/Kconfig           |  15 +
 drivers/leds/flash/Makefile          |   1 +
 drivers/leds/flash/leds-qcom-flash.c | 700 >
+++++++++++++++++++++++++++
 3 files changed, 716 insertions(+)
 create mode 100644 drivers/leds/flash/leds-qcom-flash.c

diff --git a/drivers/leds/flash/Kconfig
b/drivers/leds/flash/Kconfig
index d3eb689b193c..f36a60409290 100644
--- a/drivers/leds/flash/Kconfig
+++ b/drivers/leds/flash/Kconfig
@@ -61,6 +61,21 @@ config LEDS_MT6360
          Independent current sources supply for each flash LED >
support torch
          and strobe mode.
+config LEDS_QCOM_FLASH
+       tristate "LED support for flash module inside Qualcomm >
Technologies, Inc. PMIC"
+       depends on MFD_SPMI_PMIC || COMPILE_TEST
+       depends on LEDS_CLASS && OF
+       depends on V4L2_FLASH_LED_CLASS || !V4L2_FLASH_LED_CLASS
+       select REGMAP
+       help
+         This option enables support for the flash module found in
Qualcomm
+         Technologies, Inc. PMICs. The flash module can have 3 or
4 > flash LED
+         channels and each channel is programmable to support up
to > 1.5 A full
+         scale current. It also supports connecting two channels'
output together
+         to supply one LED component to achieve current up to 2 A.
In such case,
+         the total LED currentwill be split symmetrically on each
channel and
+         they will be enabled/disabled at the same time.
+
 config LEDS_RT4505
        tristate "LED support for RT4505 flashlight controller"
        depends on I2C && OF
diff --git a/drivers/leds/flash/Makefile >
b/drivers/leds/flash/Makefile
index 0acbddc0b91b..8a60993f1a25 100644
--- a/drivers/leds/flash/Makefile
+++ b/drivers/leds/flash/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_LEDS_AS3645A)      += leds-as3645a.o
 obj-$(CONFIG_LEDS_KTD2692)     += leds-ktd2692.o
 obj-$(CONFIG_LEDS_LM3601X)     += leds-lm3601x.o
 obj-$(CONFIG_LEDS_MAX77693)    += leds-max77693.o
+obj-$(CONFIG_LEDS_QCOM_FLASH)  += leds-qcom-flash.o
 obj-$(CONFIG_LEDS_RT4505)      += leds-rt4505.o
 obj-$(CONFIG_LEDS_RT8515)      += leds-rt8515.o
 obj-$(CONFIG_LEDS_SGM3140)     += leds-sgm3140.o
diff --git a/drivers/leds/flash/leds-qcom-flash.c >
b/drivers/leds/flash/leds-qcom-flash.c
new file mode 100644
index 000000000000..a9fcf61600c3
--- /dev/null
+++ b/drivers/leds/flash/leds-qcom-flash.c
@@ -0,0 +1,700 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights
reserved.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/leds.h>
+#include <linux/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <media/v4l2-flash-led-class.h>
+
+/* registers definitions */
+#define FLASH_TYPE_REG                 0x04
+#define FLASH_TYPE_VAL                 0x18
+
+#define FLASH_SUBTYPE_REG              0x05
+#define FLASH_SUBTYPE_3CH_VAL          0x04

PMI8998 has also a 3 channel flash subtype, but reports 0x03 as
subtype. The driver won't probe because of this since the subtype did
not match. Changing this value to 0x03 made this driver work on SDM845
based device as well with PMI8998. Would you consider supporting
SDM845+PMI8998 as well?

I just double checked, flash module in PMI8998 (with subtype 0x3) has very similar register definition as the flash module in PM8150C (with subtype 0x4) that the driver is intended to support, it's good know that it's 99% work.
I can add the 0x3 subtype support but the only problem is I couldn't find a device with PMI8998 to test it out. Would it be good if I add the support and rely on your test result?

+#define FLASH_SUBTYPE_4CH_VAL          0x07
+
+#define FLASH_TIMER_EN_BIT             BIT(7)
+#define FLASH_TIMER_VAL_MASK           GENMASK(6, 0)
+#define FLASH_TIMER_STEP_MS            10
+
+#define FLASH_STROBE_HW_SW_SEL_BIT     BIT(2)
+#define SW_STROBE_VAL                  0
+#define HW_STROBE_VAL                  1
+#define FLASH_HW_STROBE_TRIGGER_SEL_BIT        BIT(1)
+#define STROBE_LEVEL_TRIGGER_VAL       0
+#define STROBE_EDGE_TRIGGER_VAL                1
+#define FLASH_STROBE_POLARITY_BIT      BIT(0)
+#define STROBE_ACTIVE_HIGH_VAL         1
+
+#define FLASH_IRES_MASK_4CH            BIT(0)
+#define FLASH_IRES_MASK_3CH            GENMASK(1, 0)
+#define FLASH_IRES_12P5MA_VAL          0
+#define FLASH_IRES_5MA_VAL_4CH         1
+#define FLASH_IRES_5MA_VAL_3CH         3
+
+/* constants */
+#define FLASH_CURRENT_MAX_UA           1500000
+#define TORCH_CURRENT_MAX_UA           500000
+#define FLASH_TOTAL_CURRENT_MAX_UA     2000000
+#define FLASH_CURRENT_DEFAULT_UA       1000000
+#define TORCH_CURRENT_DEFAULT_UA       200000
+
+#define TORCH_IRES_UA                  5000
+#define FLASH_IRES_UA                  12500
+
+#define FLASH_TIMEOUT_MAX_US           1280000
+#define FLASH_TIMEOUT_STEP_US          10000
+
+enum hw_type {
+       QCOM_MVFLASH_3CH,
+       QCOM_MVFLASH_4CH,
+};
+
+enum led_mode {
+       FLASH_MODE,
+       TORCH_MODE,
+};
+
+enum led_strobe {
+       SW_STROBE,
+       HW_STROBE,
+};
+
+enum {
+       REG_STATUS1,
+       REG_STATUS2,
+       REG_STATUS3,
+       REG_CHAN_TIMER,
+       REG_ITARGET,
+       REG_MODULE_EN,
+       REG_IRESOLUTION,
+       REG_CHAN_STROBE,
+       REG_CHAN_EN,
+       REG_MAX_COUNT,
+};
+
+struct reg_field mvflash_3ch_regs[REG_MAX_COUNT] = {
+       REG_FIELD(0x08, 0, 7),                  /* status1      */
+       REG_FIELD(0x09, 0, 7),                  /* status2      */
+       REG_FIELD(0x0a, 0, 7),                  /* status3      */
+       REG_FIELD_ID(0x40, 0, 7, 3, 1),         /* chan_timer   */
+       REG_FIELD_ID(0x43, 0, 6, 3, 1),         /* itarget      */
+       REG_FIELD(0x46, 7, 7),                  /* module_en    */
+       REG_FIELD(0x47, 0, 5),                  /* iresolution  */
+       REG_FIELD_ID(0x49, 0, 2, 3, 1),         /* chan_strobe  */
+       REG_FIELD(0x4c, 0, 2),                  /* chan_en      */
+};

These registers map perfectly for SDM845 with PMI8998 as well, adding
support for this subtype (0x03) would be great.

+
+struct reg_field mvflash_4ch_regs[REG_MAX_COUNT] = {
+       REG_FIELD(0x06, 0, 7),                  /* status1      */
+       REG_FIELD(0x07, 0, 6),                  /* status2      */
+       REG_FIELD(0x09, 0, 7),                  /* status3      */
+       REG_FIELD_ID(0x3e, 0, 7, 4, 1),         /* chan_timer   */
+       REG_FIELD_ID(0x42, 0, 6, 4, 1),         /* itarget      */
+       REG_FIELD(0x46, 7, 7),                  /* module_en    */
+       REG_FIELD(0x49, 0, 3),                  /* iresolution  */
+       REG_FIELD_ID(0x4a, 0, 6, 4, 1),         /* chan_strobe  */
+       REG_FIELD(0x4e, 0, 3),                  /* chan_en      */
+};
+
+struct qcom_flash_led {
+       struct qcom_flash_chip          *chip;
+       struct led_classdev_flash       flash;
+       struct v4l2_flash               *v4l2_flash;
+       u32                             max_flash_current_ma;
+       u32                             max_torch_current_ma;
+       u32                             max_timeout_ms;
+       u32                             flash_current_ma;
+       u32                             flash_timeout_ms;
+       u8                              *chan_id;
+       u8                              chan_count;
+       bool                            enabled;
+};
+
+struct qcom_flash_chip {
+       struct qcom_flash_led   *leds;
+       struct regmap_field     *r_fields[REG_MAX_COUNT];
+       struct device           *dev;
+       struct mutex            lock;
+       enum hw_type            hw_type;
+       u8                      leds_count;
+       u8                      max_channels;
+       u8                      chan_en_bits;
+};
+
+static int set_flash_module_en(struct qcom_flash_led *led, bool
en)
+{
+       struct qcom_flash_chip *chip= led->chip;
+       u8 led_mask = 0, val;
+       int i, rc;
+
+       for (i = 0; i < led->chan_count; i++)
+               led_mask |= BIT(led->chan_id[i] - 1);
+
+       mutex_lock(&chip->lock);
+       if (en)
+               chip->chan_en_bits |= led_mask;
+       else
+               chip->chan_en_bits &= ~led_mask;
+
+       val = !!chip->chan_en_bits;
+       rc = regmap_field_write(chip->r_fields[REG_MODULE_EN],
val);
+       if (rc < 0)
+               dev_err(chip->dev, "write module_en failed,
rc=%d\n", > rc);
+       mutex_unlock(&chip->lock);
+
+       return rc;
+}
+
+static int set_flash_current(struct qcom_flash_led *led, u32 >
current_ma, enum led_mode mode)
+{
+       struct qcom_flash_chip *chip= led->chip;
+       u32 itarg_ua = current_ma * 1000 / led->chan_count + 1;
+       u32 ires_ua = (mode ==FLASH_MODE) ? FLASH_IRES_UA : >
TORCH_IRES_UA;
+       u8 val, shift, ires_mask =0, ires_val = 0, chan_id;
+       int i, rc;
+
+       /*
+        * Split the current across the channels and set the
+        * IRESOLUTION and ITARGET registers accordingly.
+        */
+       for (i = 0; i < led->chan_count; i++) {
+               chan_id = led->chan_id[i];
+               if (itarg_ua < ires_ua)
+                       val = 0;
+               else
+                       val = itarg_ua / ires_ua - 1;
+
+               rc = regmap_fields_write(chip-
r_fields[REG_ITARGET], > chan_id - 1, val);
+               if (rc < 0)
+                       returnrc;
+
+               if (chip->hw_type == QCOM_MVFLASH_3CH) {
+                       shift = (chan_id - 1) * 2;
+                       ires_mask |= FLASH_IRES_MASK_3CH << shift;
+                       ires_val |= ((mode == FLASH_MODE) ?
+                               (FLASH_IRES_12P5MA_VAL << shift) :
+                               (FLASH_IRES_5MA_VAL_3CH << shift));
+               } else if (chip->hw_type == QCOM_MVFLASH_4CH) {
+                       shift = chan_id - 1;
+                       ires_mask |= FLASH_IRES_MASK_4CH << shift;
+                       ires_val |= ((mode == FLASH_MODE) ?
+                               (FLASH_IRES_12P5MA_VAL << shift) :
+                               (FLASH_IRES_5MA_VAL_4CH << shift));
+               }
+       }
+
+       return > regmap_field_update_bits(chip-
r_fields[REG_IRESOLUTION], ires_mask, > ires_val);
+}
+
+static int set_flash_timeout(struct qcom_flash_led *led, u32 >
timeout_ms)
+{
+       struct qcom_flash_chip *chip= led->chip;
+       u8 val, chan_id;
+       int rc, i;
+
+       /* set SAFETY_TIMER for all the channels connected to the >
same LED */
+       timeout_ms = min_t(u32, timeout_ms, led->max_timeout_ms);
+       for (i = 0; i < led->chan_count; i++) {
+               chan_id = led->chan_id[i];
+               val = timeout_ms / FLASH_TIMER_STEP_MS;
+               val = clamp_t(u8, val, 0, FLASH_TIMER_VAL_MASK);
+               if (timeout_ms)
+                       val |= FLASH_TIMER_EN_BIT;
+
+               rc = > regmap_fields_write(chip-
r_fields[REG_CHAN_TIMER], chan_id - 1, > val);
+               if (rc < 0)
+                       returnrc;
+       }
+
+       return 0;
+}
+
+static int set_flash_strobe(struct qcom_flash_led *led, enum >
led_strobe strobe, bool state)
+{
+       struct qcom_flash_chip *chip= led->chip;
+       u8 mask, val, chan_id = 0,chan_mask = 0;
+       int rc, i;
+
+       /* Set SW strobe config for all channels connected to the
LED > */
+       for (i = 0; i < led->chan_count; i++) {
+               chan_id = led->chan_id[i];
+               if (strobe == SW_STROBE)
+                       val =
FIELD_PREP(FLASH_STROBE_HW_SW_SEL_BIT, > SW_STROBE_VAL);
+               else
+                       val =
FIELD_PREP(FLASH_STROBE_HW_SW_SEL_BIT, > HW_STROBE_VAL);
+
+               val |= FIELD_PREP(FLASH_HW_STROBE_TRIGGER_SEL_BIT,
STROBE_LEVEL_TRIGGER_VAL) |
+                       FIELD_PREP(FLASH_STROBE_POLARITY_BIT, >
STROBE_ACTIVE_HIGH_VAL);
+               rc = > regmap_fields_write(chip-
r_fields[REG_CHAN_STROBE], chan_id - 1, > val);
+               if (rc < 0)
+                       returnrc;
+
+               chan_mask |= BIT(chan_id - 1);
+       }
+
+       /* enable/disable flash channels */
+       mask = chan_mask;
+       val = state ? mask : 0;
+       rc = regmap_field_update_bits(chip->r_fields[REG_CHAN_EN],
mask, val);
+       if (rc < 0)
+               return rc;
+
+       led->enabled = state;
+       return 0;
+}
+
+static int qcom_flash_brightness_set(struct led_classdev_flash >
*fled_cdev, u32 brightness)
+{
+       struct qcom_flash_led *led = container_of(fled_cdev, struct
qcom_flash_led, flash);
+
+       led->flash_current_ma = min_t(u32, led-
max_flash_current_ma, > brightness / 1000);
+       return 0;
+}

This doesn't seem to work in torch mode for me on PMI8998. If the
brightness is 0, the torch is OFF as expected, but when the torch is
ON, you cannot control the brightness. The brightness is the same for
[1, 255]. If the hardware cannot change the brightness in torch mode,
it would be nice to report a max_brightness value of 1 instead of 255
for userspace. This could be a limitation of the PMI8998, not sure.
Do you have any insights here? This driver is already 99% working for
SDM845+PMI8998.

Flash mode works great, timeout & brightness can be configured just
fine.


Here, function qcom_flash_brightness_set() is used for setting brightness in flash mode and it was supposed to be working with following commands combination:
echo xxx > flash_brightness
echo 1 > flash_strobe (you will need to toggle flash_strobe when you enabling it again)

Can you check if you can see the brightness change in flash mode when you updating the flash_brightness value with these commands?

You can echo any value between [0, max_flash_brightness] into the flash_brightness, there is a "max_flash_brightness" sysfs node and the value comes from DT property "flash-max-microamp", ex. my dtsi node has "flash-max-microamp = <2000000>;" defined so I am having following value for max_flash_brightness:

kalama:/sys/class/leds/white:flash-0 # cat max_flash_brightness
2000000

And by default flash mode uses 12500uA resolution so you won't see brightness change when you update it with values between [1, 12500].

If you want to update the brightness for torch node, you can directly update the "brightness" node with values between [0, 255], and it's mapping to the torch current between [0, led-max-microamp]. "led-max-microamp" is also has value coming from the DT property.

This worked at my side on both pm8150C and pm8550.I think it should work on PMI8998 as well because the flash module in it is very similar to the one in PM8150c. Let me know if you still see such issues at your side.
Thanks

+
+static int qcom_flash_timeout_set(struct led_classdev_flash >
*fled_cdev, u32 timeout)
+{
+       struct qcom_flash_led *led = container_of(fled_cdev, struct
qcom_flash_led, flash);
+
+       led->flash_timeout_ms = timeout / 1000;
+       return 0;
+}
+
+static int qcom_flash_strobe_set(struct led_classdev_flash >
*fled_cdev, bool state)
+{
+       struct qcom_flash_led *led = container_of(fled_cdev, struct
qcom_flash_led, flash);
+       int rc;
+
+       rc = set_flash_current(led, led->flash_current_ma, >
FLASH_MODE);
+       if (rc < 0)
+               return rc;
+
+       rc = set_flash_timeout(led, led->flash_timeout_ms);
+       if (rc < 0)
+               return rc;
+
+       rc = set_flash_module_en(led, state);
+       if (rc < 0)
+               return rc;
+
+       return set_flash_strobe(led,SW_STROBE, state);
+}
+
+static int qcom_flash_strobe_get(struct led_classdev_flash >
*fled_cdev, bool *state)
+{
+       struct qcom_flash_led *led = container_of(fled_cdev, struct
qcom_flash_led, flash);
+
+       *state = led->enabled;
+       return 0;
+}
+
+static int qcom_flash_fault_get(struct led_classdev_flash >
*fled_cdev, u32 *fault)
+{
+       struct qcom_flash_led *led = container_of(fled_cdev, struct
qcom_flash_led, flash);
+       struct qcom_flash_chip *chip= led->chip;
+       u8 shift, chan_id = 0, chan_mask = 0;
+       u8 ot_mask = 0, oc_mask = 0, uv_mask = 0;
+       u32 val, fault_sts = 0;
+       int i, rc;
+
+       rc = regmap_field_read(chip->r_fields[REG_STATUS1], &val);
+       if (rc < 0)
+               return rc;
+
+       for (i = 0; i < led->chan_count; i++) {
+               chan_id = led->chan_id[i];
+               shift = (chan_id - 1) * 2;
+               if (val & BIT(shift))
+                       fault_sts |= LED_FAULT_SHORT_CIRCUIT;
+               chan_mask |= BIT(chan_id - 1);
+       }
+
+       rc = regmap_field_read(chip->r_fields[REG_STATUS2], &val);
+       if (rc < 0)
+               return rc;
+
+       if (chip->hw_type == QCOM_MVFLASH_3CH) {
+               ot_mask = 0x0f;
+               oc_mask = 0xe0;
+               uv_mask = 0x10;
+       } else if (chip->hw_type == QCOM_MVFLASH_4CH) {
+               ot_mask = 0x70;
+               oc_mask = 0x0e;
+               uv_mask = 0x01;
+       }
+
+       if (val & ot_mask)
+               fault_sts |= LED_FAULT_OVER_TEMPERATURE;
+       if (val & oc_mask)
+               fault_sts |= LED_FAULT_OVER_CURRENT;
+       if (val & uv_mask)
+               fault_sts |= LED_FAULT_INPUT_VOLTAGE;
+
+       rc = regmap_field_read(chip->r_fields[REG_STATUS3], &val);
+       if (rc < 0)
+               return rc;
+
+       if (chip->hw_type == QCOM_MVFLASH_3CH) {
+               if (val & chan_mask)
+                       fault_sts |= LED_FAULT_TIMEOUT;
+       } else if (chip->hw_type == QCOM_MVFLASH_4CH) {
+               for (i = 0; i < led->chan_count; i++) {
+                       chan_id = led->chan_id[i];
+                       shift = (chan_id - 1) * 2;
+                       if (val & BIT(shift))
+                               fault_sts |= LED_FAULT_TIMEOUT;
+               }
+       }
+
+       *fault = fault_sts;
+       return 0;
+}
+
+static int qcom_flash_led_brightness_set(struct led_classdev >
*led_cdev,
+                                       enum led_brightness >
brightness)
+{
+       struct led_classdev_flash *fled_cdev =
+               container_of(led_cdev, struct led_classdev_flash, >
led_cdev);
+       struct qcom_flash_led *led =
+               container_of(fled_cdev, struct qcom_flash_led, >
flash);
+       u32 current_ma = brightness * led->max_torch_current_ma / >
LED_FULL;
+       bool enable = !!brightness;
+       int rc;
+
+       rc = set_flash_current(led, current_ma, TORCH_MODE);
+       if (rc < 0)
+               return rc;
+
+       /* disable flash timeout fortorch LED */
+       rc = set_flash_timeout(led, 0);
+       if (rc < 0)
+               return rc;
+
+       rc = set_flash_module_en(led, enable);
+       if (rc < 0)
+               return rc;
+
+       return set_flash_strobe(led,SW_STROBE, enable);
+}
+
+static const struct led_flash_ops qcom_flash_ops = {
+       .flash_brightness_set = qcom_flash_brightness_set,
+       .strobe_set = qcom_flash_strobe_set,
+       .strobe_get = qcom_flash_strobe_get,
+       .timeout_set = qcom_flash_timeout_set,
+       .fault_get = qcom_flash_fault_get,
+};
+
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+static int qcom_flash_external_strobe_set(struct v4l2_flash >
*v4l2_flash, bool enable)
+{
+       struct led_classdev_flash *flash = v4l2_flash->fled_cdev;
+       struct qcom_flash_led *led = container_of(flash, struct >
qcom_flash_led, flash);
+       int rc;
+
+       rc = set_flash_module_en(led, enable);
+       if (rc < 0)
+               return rc;
+
+       if (enable)
+               return set_flash_strobe(led, HW_STROBE, true);
+       else
+               return set_flash_strobe(led, SW_STROBE, false);
+}
+
+static enum led_brightness qcom_flash_intensity_to_led_brightness(
+               struct v4l2_flash *v4l2_flash, s32 intensity)
+{
+       struct led_classdev_flash *flash = v4l2_flash->fled_cdev;
+       struct qcom_flash_led *led = container_of(flash, struct >
qcom_flash_led, flash);
+       u32 current_ma = intensity/ 1000;
+
+       current_ma = min_t(u32, current_ma, > led-
max_torch_current_ma);
+       if (!current_ma)
+               return LED_OFF;
+
+       return current_ma * LED_FULL/ led->max_torch_current_ma;
+}
+
+static s32 qcom_flash_brightness_to_led_intensity(struct
v4l2_flash > *v4l2_flash,
+                                       enum led_brightness >
brightness)
+{
+       struct led_classdev_flash *flash = v4l2_flash->fled_cdev;
+       struct qcom_flash_led *led = container_of(flash, struct >
qcom_flash_led, flash);
+
+       return (brightness * led->max_torch_current_ma * 1000) / >
LED_FULL;
+}
+
+static const struct v4l2_flash_ops qcom_v4l2_flash_ops = {
+       .external_strobe_set = qcom_flash_external_strobe_set,
+       .intensity_to_led_brightness= >
qcom_flash_intensity_to_led_brightness,
+       .led_brightness_to_intensity= >
qcom_flash_brightness_to_led_intensity,
+};
+
+static int qcom_flash_v4l2_init(struct qcom_flash_led *led, struct
fwnode_handle *fwnode)
+{
+       struct v4l2_flash_config v4l2_cfg = {0};
+       struct led_flash_setting *s = &v4l2_cfg.intensity;
+
+       if (!(led->flash.led_cdev.flags & LED_DEV_CAP_FLASH))
+               return 0;
+
+       s->min = s->step = TORCH_IRES_UA * led->chan_count;
+       s->max = led->max_torch_current_ma * 1000;
+       s->val = min_t(u32, s->max, TORCH_CURRENT_DEFAULT_UA);
+
+       strscpy(v4l2_cfg.dev_name, >led->flash.led_cdev.dev-
kobj.name,
+                                       sizeof(v4l2_cfg.dev_name));
+       v4l2_cfg.has_external_strobe= 1;
+       v4l2_cfg.flash_faults = LED_FAULT_INPUT_VOLTAGE | >
LED_FAULT_OVER_CURRENT |
+               LED_FAULT_SHORT_CIRCUIT |
LED_FAULT_OVER_TEMPERATURE > | LED_FAULT_TIMEOUT;
+
+       led->v4l2_flash = v4l2_flash_init(led->chip->dev, fwnode, >
&led->flash,
+                                       &qcom_v4l2_flash_ops, >
&v4l2_cfg);
+       return PTR_ERR_OR_ZERO(led->v4l2_flash);
+}
+# else
+static int qcom_flash_v4l2_init(struct qcom_flash_led *led, struct
fwnode_handle *fwnode)
+{
+       return 0;
+}
+#endif
+
+static int qcom_flash_register_led_device(struct device *parent,
+               struct fwnode_handle *node, struct qcom_flash_led >
*led)
+{
+       struct qcom_flash_chip *chip= led->chip;
+       struct led_init_data init_data;
+       struct led_classdev_flash *flash;
+       struct led_flash_setting *s;
+       u32 count, val;
+       u32 channels[4];
+       int i, rc;
+
+       flash = &led->flash;
+       count = fwnode_property_count_u32(node, "led-sources");
+       if (count <= 0) {
+               dev_err(chip->dev, "No led-sources specified\n");
+               return -ENODEV;
+       }
+
+       if (count > chip->max_channels) {
+               dev_err(chip->dev, "led-sources count %u exceeds >
maximum channel count %u\n",
+                               count, chip->max_channels);
+               return -EINVAL;
+       }
+
+       rc = fwnode_property_read_u32_array(node, "led-sources", >
channels, count);
+       if (rc < 0) {
+               dev_err(chip->dev, "get led-sources failed,
rc=%d\n", > rc);
+               return rc;
+       }
+
+       led->chan_count = count;
+       led->chan_id = devm_kcalloc(chip->dev, count, sizeof(u8), >
GFP_KERNEL);
+       if (!led->chan_id)
+               return -ENOMEM;
+
+       for (i = 0; i < count; i++) {
+               if (channels[i] > chip->max_channels) {
+                       dev_err(chip->dev, "led-source out of HW >
support range [1-%u]\n",
+                                       chip->max_channels);
+                       return-EINVAL;
+               }
+
+               led->chan_id[i] = channels[i];
+       }
+
+       rc = fwnode_property_read_u32(node, "led-max-microamp", >
&val);
+       if (rc < 0) {
+               dev_err(chip->dev, "Get led-max-microamp failed, >
rc=%d\n", rc);
+               return rc;
+       }
+
+       if (!val) {
+               dev_err(chip->dev, "led-max-microamp shouldn't be >
0\n");
+               return -EINVAL;
+       }
+
+       val = min_t(u32, val, TORCH_CURRENT_MAX_UA * > led-
chan_count);
+       led->max_torch_current_ma = val / 1000;
+
+       if (fwnode_property_present(node, "flash-max-microamp")) {
+               flash->led_cdev.flags |= LED_DEV_CAP_FLASH;
+               rc = fwnode_property_read_u32(node, > "flash-max-
microamp", &val);
+               if (rc < 0) {
+                       dev_err(chip->dev, "Get flash-max-microamp
failed, rc=%d\n", rc);
+                       returnrc;
+               }
+
+               val = min_t(u32, val, FLASH_CURRENT_MAX_UA * > led-
chan_count);
+               val = min_t(u32, val, FLASH_TOTAL_CURRENT_MAX_UA);
+               s = &flash->brightness;
+               s->min = s->step = FLASH_IRES_UA * led->chan_count;
+               s->max = val;
+               s->val = min_t(u32, val, FLASH_CURRENT_DEFAULT_UA);
+               led->max_flash_current_ma = val / 1000;
+               led->flash_current_ma = s->val / 1000;
+
+               rc = fwnode_property_read_u32(node, > "flash-max-
timeout-us", &val);
+               if (rc < 0) {
+                       dev_err(chip->dev, "Get flash-max-timeout-
us > failed, rc=%d\n", rc);
+                       returnrc;
+               }
+
+               val = min_t(u32, val, FLASH_TIMEOUT_MAX_US);
+               s = &flash->timeout;
+               s->min = s->step = FLASH_TIMEOUT_STEP_US;
+               s->val = s->max = val;
+               led->max_timeout_ms = led->flash_timeout_ms = val /
1000;
+
+               flash->ops = &qcom_flash_ops;
+       }
+
+       flash->led_cdev.brightness_set_blocking = >
qcom_flash_led_brightness_set;
+       init_data.fwnode = node;
+       init_data.devicename = NULL;
+       init_data.default_label = NULL;
+       init_data.devname_mandatory = false;
+       rc = devm_led_classdev_flash_register_ext(parent, flash, >
&init_data);
+       if (rc < 0) {
+               dev_err(chip->dev, "Register flash LED classdev >
failed, rc=%d\n", rc);
+               return rc;
+       }
+
+       return qcom_flash_v4l2_init(led, node);
+}
+
+static int qcom_flash_led_probe(struct platform_device *pdev)
+{
+       struct qcom_flash_chip *chip;
+       struct qcom_flash_led *led;
+       struct fwnode_handle *child;
+       struct device *dev = &pdev->dev;
+       struct regmap *map;
+       struct reg_field *regs;
+       int count, i, rc;
+       u32 val, reg_base;
+
+       chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+       if (!chip)
+               return -ENOMEM;
+
+       map = dev_get_regmap(dev->parent, NULL);
+       if (!map) {
+               dev_err(dev, "Failed to get parent regmap\n");
+               return -EINVAL;
+       }
+
+       rc = fwnode_property_read_u32(dev->fwnode, "reg",
&reg_base);
+       if (rc < 0) {
+               dev_err(dev, "Failed to get register base address,
rc=%d\n", rc);
+               return rc;
+       }
+
+       rc = regmap_read(map, reg_base + FLASH_TYPE_REG, &val);
+       if (rc < 0) {
+               dev_err(dev, "Read flash module type failed, >
rc=%d\n", rc);
+               return rc;
+       }
+
+       if (val != FLASH_TYPE_VAL){
+               dev_err(dev, "type %#x is not a flash module\n", >
val);
+               return -ENODEV;
+       }
+
+       rc = regmap_read(map, reg_base + FLASH_SUBTYPE_REG, &val);
+       if (rc < 0) {
+               dev_err(dev, "Read flash module subtype failed, >
rc=%d\n", rc);
+               return rc;
+       }
+
+       if (val == FLASH_SUBTYPE_3CH_VAL) {
+               chip->hw_type = QCOM_MVFLASH_3CH;
+               chip->max_channels = 3;
+               regs = mvflash_3ch_regs;
+       } else if (val == FLASH_SUBTYPE_4CH_VAL) {
+               chip->hw_type = QCOM_MVFLASH_4CH;
+               chip->max_channels = 4;
+               regs = mvflash_4ch_regs;
+       } else {
+               dev_err(dev, "flash subtype %#x is not yet >
supported\n", val);
+               return -ENODEV;
+       }
+
+       for (i = 0; i < REG_MAX_COUNT; i++)
+               regs[i].reg += reg_base;
+
+       rc = devm_regmap_field_bulk_alloc(dev, map, chip->r_fields,
regs, REG_MAX_COUNT);
+       if (rc < 0) {
+               dev_err(dev, "failed to alloc regmap filed,
rc=%d\n", > rc);
+               return rc;
+       }
+
+       chip->dev = dev;
+       platform_set_drvdata(pdev, chip);
+       mutex_init(&chip->lock);
+       count = device_get_child_node_count(dev);
+       if (count == 0 || count > chip->max_channels) {
+               dev_err(dev, "No child or child count exceeds
%d\n", > chip->max_channels);
+               return -EINVAL;
+       }
+
+       chip->leds = devm_kcalloc(dev, count, sizeof(*chip->leds),
GFP_KERNEL);
+       if (!chip->leds)
+               return -ENOMEM;
+
+       device_for_each_child_node(dev, child) {
+               led = &chip->leds[chip->leds_count];
+               led->chip = chip;
+               rc = qcom_flash_register_led_device(dev, child,
led);
+               if (rc < 0)
+                       goto release;
+
+               chip->leds_count++;
+       }
+
+       return 0;
+release:
+       while (chip->leds && chip->leds_count--)
+               v4l2_flash_release(chip->leds[chip-
leds_count].v4l2_> flash);
+       return rc;
+}
+
+static int qcom_flash_led_remove(struct platform_device *pdev)
+{
+       struct qcom_flash_chip *chip= platform_get_drvdata(pdev);
+
+       while (chip->leds_count--)
+               v4l2_flash_release(chip->leds[chip-
leds_count].v4l2_> flash);
+
+       mutex_destroy(&chip->lock);
+       return 0;
+}
+
+static const struct of_device_id qcom_flash_led_match_table[] = {
+       { .compatible = "qcom,spmi-flash-led" },
+       { }
+};
+
+static struct platform_driver qcom_flash_led_driver = {
+       .driver = {
+               .name = "leds-qcom-flash",
+               .of_match_table = qcom_flash_led_match_table,
+       },
+       .probe = qcom_flash_led_probe,
+       .remove = qcom_flash_led_remove,
+};
+
+module_platform_driver(qcom_flash_led_driver);
+
+MODULE_DESCRIPTION("QCOM Flash LED driver");
+MODULE_LICENSE("GPL");

Kind regards,
Dylan Van Assche