Message-ID: <e6df1e25-51fc-0a92-50bd-0eb8d98cf1d8@quicinc.com>
Date:   Thu, 2 Mar 2023 11:36:06 +0800
From:   Fenglin Wu <quic_fenglinw@...cinc.com>
To:     Lee Jones <lee@...nel.org>
CC:     <linux-arm-msm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <pavel@....cz>, <krzysztof.kozlowski@...aro.org>,
        <linux-leds@...r.kernel.org>, <quic_collinsd@...cinc.com>,
        <quic_subbaram@...cinc.com>, Luca Weiss <luca.weiss@...rphone.com>
Subject: Re: [PATCH v7 1/2] leds: flash: add driver to support flash LED
 module in QCOM PMICs



On 3/2/2023 12:04 AM, Lee Jones wrote:
> On Fri, 03 Feb 2023, Fenglin Wu wrote:
> 
>> 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@...cinc.com>
>> Tested-by: Luca Weiss <luca.weiss@...rphone.com> # sm7225-fairphone-fp4 + pm6150l
>> ---
> 
> Change log?

The change log was updated in the cover letter

> 
>>   drivers/leds/flash/Kconfig           |  15 +
>>   drivers/leds/flash/Makefile          |   1 +
>>   drivers/leds/flash/leds-qcom-flash.c | 769 +++++++++++++++++++++++++++
>>   3 files changed, 785 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 current will 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..51ef60e2338c
>> --- /dev/null
>> +++ b/drivers/leds/flash/leds-qcom-flash.c
>> @@ -0,0 +1,769 @@
>> +// 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
>> +#define FLASH_SUBTYPE_4CH_VAL		0x07
>> +
>> +#define FLASH_STS_3CH_OTST1		BIT(0)
>> +#define FLASH_STS_3CH_OTST2		BIT(1)
>> +#define FLASH_STS_3CH_OTST3		BIT(2)
>> +#define FLASH_STS_3CH_BOB_THM_OVERLOAD	BIT(3)
>> +#define FLASH_STS_3CH_VPH_DROOP		BIT(4)
>> +#define FLASH_STS_3CH_BOB_ILIM_S1	BIT(5)
>> +#define FLASH_STS_3CH_BOB_ILIM_S2	BIT(6)
>> +#define FLASH_STS_3CH_BCL_IBAT		BIT(7)
>> +
>> +#define FLASH_STS_4CH_VPH_LOW		BIT(0)
>> +#define FLASH_STS_4CH_BCL_IBAT		BIT(1)
>> +#define FLASH_STS_4CH_BOB_ILIM_S1	BIT(2)
>> +#define FLASH_STS_4CH_BOB_ILIM_S2	BIT(3)
>> +#define FLASH_STS_4CH_OTST2		BIT(4)
>> +#define FLASH_STS_4CH_OTST1		BIT(5)
>> +#define FLASH_STS_4CHG_BOB_THM_OVERLOAD	BIT(6)
>> +
>> +#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
>> +
>> +#define UA_PER_MA			1000
>> +
>> +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	*/
>> +};
>> +
>> +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 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;
>> +	void				*priv_data;
> 
> How is this anything other than an obfuscated version of the previous
> implementation?
> 
> Right, let's go back to first principles:
> 
> Why do you need a separate 'chip' structure anyway?
> 
>> +};
>> +
>> +struct qcom_flash_chip {
>> +	struct qcom_flash_led	*leds;
> 
> Goes away if you just use qcom_flash_led.
> 
>> +	struct regmap_field     *r_fields[REG_MAX_COUNT];
> 
> This looks like it might be an issue.
> 
> If so, why not have another structure that all LEDs get a pointer to,
> but does not have a pointer to the LEDs, thus satisfying our one-way
> rule?
> 
> As far as I can see, the only time you need to point from 'chip' to
> 'leds' is to release v4l2_flash.  If you can find another sane way of
> doing that, you can drop the chip to leds link.
> 
> Take a peak at some other drivers, to see how they manage that.
> 
Thanks.
Right, releasing v4l2_flash in remove() is the only usage for 'chip'. I 
was thinking to keep tracking of the 'v4l2_flash' pointer in 
'qcom_flash_led' for later usage so I tracked all the 'qcom_flash_led" 
pointer in "qcom_flash_chip" as well, but it seems not necessary to keep 
the v4l2_flash pointer in 'qcom_flash_led" chip. I will update this like 
you suggested to avoid the interwoven reference.

>> +	struct device		*dev;
> 
> Can be derived from led_classdev_flash.
> 
>> +	struct mutex		lock;
> 
> Any reason why the lock can't be per LED?
> 
The lock has a very simple usage of protecting the variable 
'chan_en_bits' when programming the 'MODULE_EN' register.
It's basically a register with single valid bit to enable/disable the HW 
module and it impacts all flash LED channels.

>> +	enum hw_type		hw_type;
>> +	u8			leds_count;
> 
> Goes away if you just use qcom_flash_led.
> 
>> +	u8			max_channels;
> 
> What is a channel?  And how does it relate to the LEDs?
> 
> Looks like the LED structure also has a "chan_count" attribute.
> 

A channel is a current sink that can drive the external LED component 
with programmble current upto 1.5A. Flash module with different 
'hw_type' has different channel numers, 3 or 4, so we have the 
'max_channels' variable here.

If anyone expects to driver a flash LED more than 1.5A, two channels can 
be ganged together in HW design and the flash LED can be driven upto 2A, 
the flash LED current will be split equally on these two channels. And 
the 'chan_count' in 'qcom_flash_led' is for this usage, to specify how 
many channels are ganged to drive the flash LED.


>> +	u8			chan_en_bits;
>> +};
>> +
>> +static inline void *flash_led_get_priv_data(struct qcom_flash_led *led)
>> +{
>> +	return led->priv_data;
>> +}
>> +
>> +static int set_flash_module_en(struct qcom_flash_led *led, bool en)
>> +{
>> +	struct qcom_flash_chip *chip = flash_led_get_priv_data(led);
>> +	u8 led_mask = 0, enable;
>> +	int i, rc;
>> +
>> +	for (i = 0; i < led->chan_count; i++)
>> +		led_mask |= BIT(led->chan_id[i]);
>> +
>> +	mutex_lock(&chip->lock);
>> +	if (en)
>> +		chip->chan_en_bits |= led_mask;
>> +	else
>> +		chip->chan_en_bits &= ~led_mask;
>> +
>> +	enable = !!chip->chan_en_bits;
>> +	rc = regmap_field_write(chip->r_fields[REG_MODULE_EN], enable);
>> +	if (rc)
>> +		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 = flash_led_get_priv_data(led);
>> +	u32 itarg_ua, ires_ua;
>> +	u8 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.
>> +	 */
>> +	itarg_ua = (current_ma * UA_PER_MA) / led->chan_count + 1;
>> +	ires_ua = (mode == FLASH_MODE) ? FLASH_IRES_UA : TORCH_IRES_UA;
>> +
>> +	for (i = 0; i < led->chan_count; i++) {
>> +		u8 itarget = 0;
>> +
>> +		if (itarg_ua > ires_ua)
>> +			itarget = itarg_ua / ires_ua - 1;
>> +
>> +		chan_id = led->chan_id[i];
>> +
>> +		rc = regmap_fields_write(chip->r_fields[REG_ITARGET], chan_id, itarget);
>> +		if (rc)
>> +			return rc;
>> +
>> +		if (chip->hw_type == QCOM_MVFLASH_3CH) {
>> +			shift = chan_id * 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;
>> +			ires_mask |= FLASH_IRES_MASK_4CH << shift;
>> +			ires_val |= ((mode == FLASH_MODE) ?
>> +				(FLASH_IRES_12P5MA_VAL << shift) :
>> +				(FLASH_IRES_5MA_VAL_4CH << shift));
>> +		} else {
>> +			dev_err(chip->dev, "HW type %d is not supported\n", chip->hw_type);
>> +			return -ENOTSUPP;
>> +		}
>> +	}
>> +
>> +	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 = flash_led_get_priv_data(led);
>> +	u8 timer, 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];
>> +
>> +		timer = timeout_ms / FLASH_TIMER_STEP_MS;
>> +		timer = clamp_t(u8, timer, 0, FLASH_TIMER_VAL_MASK);
>> +
>> +		if (timeout_ms)
>> +			timer |= FLASH_TIMER_EN_BIT;
>> +
>> +		rc = regmap_fields_write(chip->r_fields[REG_CHAN_TIMER], chan_id, timer);
>> +		if (rc)
>> +			return rc;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int set_flash_strobe(struct qcom_flash_led *led, enum led_strobe strobe, bool state)
>> +{
>> +	struct qcom_flash_chip *chip = flash_led_get_priv_data(led);
>> +	u8 strobe_sel, chan_en, chan_id, 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)
>> +			strobe_sel = FIELD_PREP(FLASH_STROBE_HW_SW_SEL_BIT, SW_STROBE_VAL);
>> +		else
>> +			strobe_sel = FIELD_PREP(FLASH_STROBE_HW_SW_SEL_BIT, HW_STROBE_VAL);
>> +
>> +		strobe_sel |=
>> +			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, strobe_sel);
>> +		if (rc)
>> +			return rc;
>> +
>> +		chan_mask |= BIT(chan_id);
>> +	}
>> +
>> +	/* Enable/disable flash channels */
>> +	chan_en = state ? chan_mask : 0;
>> +	rc = regmap_field_update_bits(chip->r_fields[REG_CHAN_EN], chan_mask, chan_en);
>> +	if (rc)
>> +		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 / UA_PER_MA);
>> +	return 0;
>> +}
>> +
>> +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 / USEC_PER_MSEC;
>> +	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)
>> +		return rc;
>> +
>> +	rc = set_flash_timeout(led, led->flash_timeout_ms);
>> +	if (rc)
>> +		return rc;
>> +
>> +	rc = set_flash_module_en(led, state);
>> +	if (rc)
>> +		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 = flash_led_get_priv_data(led);
>> +	u8 shift, chan_id, chan_mask = 0;
>> +	u8 ot_mask, oc_mask, uv_mask;
>> +	u32 val, fault_sts = 0;
>> +	int i, rc;
>> +
>> +	rc = regmap_field_read(chip->r_fields[REG_STATUS1], &val);
>> +	if (rc)
>> +		return rc;
>> +
>> +	for (i = 0; i < led->chan_count; i++) {
>> +		chan_id = led->chan_id[i];
>> +		shift = chan_id * 2;
>> +
>> +		if (val & BIT(shift))
>> +			fault_sts |= LED_FAULT_SHORT_CIRCUIT;
>> +
>> +		chan_mask |= BIT(chan_id);
>> +	}
>> +
>> +	rc = regmap_field_read(chip->r_fields[REG_STATUS2], &val);
>> +	if (rc)
>> +		return rc;
>> +
>> +	if (chip->hw_type == QCOM_MVFLASH_3CH) {
>> +		ot_mask = FLASH_STS_3CH_OTST1 |
>> +			  FLASH_STS_3CH_OTST2 |
>> +			  FLASH_STS_3CH_OTST3 |
>> +			  FLASH_STS_3CH_BOB_THM_OVERLOAD;
>> +		oc_mask = FLASH_STS_3CH_BOB_ILIM_S1 |
>> +			  FLASH_STS_3CH_BOB_ILIM_S2 |
>> +			  FLASH_STS_3CH_BCL_IBAT;
>> +		uv_mask = FLASH_STS_3CH_VPH_DROOP;
>> +	} else if (chip->hw_type == QCOM_MVFLASH_4CH) {
>> +		ot_mask = FLASH_STS_4CH_OTST2 |
>> +			  FLASH_STS_4CH_OTST1 |
>> +			  FLASH_STS_4CHG_BOB_THM_OVERLOAD;
>> +		oc_mask = FLASH_STS_4CH_BCL_IBAT |
>> +			  FLASH_STS_4CH_BOB_ILIM_S1 |
>> +			  FLASH_STS_4CH_BOB_ILIM_S2;
>> +		uv_mask = FLASH_STS_4CH_VPH_LOW;
>> +	}
>> +
>> +	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)
>> +		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 * 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);
> 
> lcdev_to_flcdev()
> 
>> +	struct qcom_flash_led *led =
>> +		container_of(fled_cdev, struct qcom_flash_led, flash);
> 
> Please create a helper similar to above.
> 
> flcdev_to_qcom_fled()
> 
>> +	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)
>> +		return rc;
>> +
>> +	/* Disable flash timeout for torch LED */
>> +	rc = set_flash_timeout(led, 0);
>> +	if (rc)
>> +		return rc;
>> +
>> +	rc = set_flash_module_en(led, enable);
>> +	if (rc)
>> +		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)
>> +		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 / UA_PER_MA;
>> +
>> +	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 * UA_PER_MA) / 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 qcom_flash_chip *chip = flash_led_get_priv_data(led);
>> +	struct v4l2_flash_config v4l2_cfg = { 0 };
>> +	struct led_flash_setting *intensity = &v4l2_cfg.intensity;
>> +
>> +	if (!(led->flash.led_cdev.flags & LED_DEV_CAP_FLASH))
>> +		return 0;
>> +
>> +	intensity->min = intensity->step = TORCH_IRES_UA * led->chan_count;
>> +	intensity->max = led->max_torch_current_ma * UA_PER_MA;
>> +	intensity->val = min_t(u32, intensity->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 = true;
>> +	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(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 = flash_led_get_priv_data(led);
>> +	struct led_init_data init_data;
>> +	struct led_classdev_flash *flash = &led->flash;
>> +	struct led_flash_setting *brightness, *timeout;
>> +	u32 count, current_ua, timeout_us;
>> +	u32 channels[4];
>> +	int i, rc;
>> +
>> +	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, "Failed to read led-sources property, 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] == 0) || (channels[i] > chip->max_channels)) {
>> +			dev_err(chip->dev, "led-source out of HW support range [1-%u]\n",
>> +					chip->max_channels);
>> +			return -EINVAL;
>> +		}
>> +
>> +		/* Make chan_id indexing from 0 */
>> +		led->chan_id[i] = channels[i] - 1;
>> +	}
>> +
>> +	rc = fwnode_property_read_u32(node, "led-max-microamp", &current_ua);
>> +	if (rc < 0) {
>> +		dev_err(chip->dev, "Failed to read led-max-microamp property, rc=%d\n", rc);
>> +		return rc;
>> +	}
>> +
>> +	if (current_ua == 0) {
>> +		dev_err(chip->dev, "led-max-microamp shouldn't be 0\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	current_ua = min_t(u32, current_ua, TORCH_CURRENT_MAX_UA * led->chan_count);
>> +	led->max_torch_current_ma = current_ua / UA_PER_MA;
>> +
>> +	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", &current_ua);
>> +		if (rc < 0) {
>> +			dev_err(chip->dev, "Failed to read flash-max-microamp property, rc=%d\n",
>> +					rc);
>> +			return rc;
>> +		}
>> +
>> +		current_ua = min_t(u32, current_ua, FLASH_CURRENT_MAX_UA * led->chan_count);
>> +		current_ua = min_t(u32, current_ua, FLASH_TOTAL_CURRENT_MAX_UA);
>> +
>> +		/* Initialize flash class LED device brightness settings */
>> +		brightness = &flash->brightness;
>> +		brightness->min = brightness->step = FLASH_IRES_UA * led->chan_count;
>> +		brightness->max = current_ua;
>> +		brightness->val = min_t(u32, current_ua, FLASH_CURRENT_DEFAULT_UA);
>> +
>> +		led->max_flash_current_ma = current_ua / UA_PER_MA;
>> +		led->flash_current_ma = brightness->val / UA_PER_MA;
>> +
>> +		rc = fwnode_property_read_u32(node, "flash-max-timeout-us", &timeout_us);
>> +		if (rc < 0) {
>> +			dev_err(chip->dev, "Failed to read flash-max-timeout-us property, rc=%d\n",
>> +					rc);
>> +			return rc;
>> +		}
>> +
>> +		timeout_us = min_t(u32, timeout_us, FLASH_TIMEOUT_MAX_US);
>> +
>> +		/* Initialize flash class LED device timeout settings */
>> +		timeout = &flash->timeout;
>> +		timeout->min = timeout->step = FLASH_TIMEOUT_STEP_US;
>> +		timeout->val = timeout->max = timeout_us;
>> +
>> +		led->max_timeout_ms = led->flash_timeout_ms = timeout_us / USEC_PER_MSEC;
>> +
>> +		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 *regmap;
>> +	struct reg_field *regs;
>> +	int count, i, rc;
>> +	u32 val, reg_base;
>> +
>> +	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
>> +	if (!chip)
>> +		return -ENOMEM;
>> +
>> +	regmap = dev_get_regmap(dev->parent, NULL);
>> +	if (!regmap) {
>> +		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(regmap, reg_base + FLASH_TYPE_REG, &val);
>> +	if (rc < 0) {
>> +		dev_err(dev, "Read flash LED module type failed, rc=%d\n", rc);
>> +		return rc;
>> +	}
>> +
>> +	if (val != FLASH_TYPE_VAL) {
>> +		dev_err(dev, "type %#x is not a flash LED module\n", val);
>> +		return -ENODEV;
>> +	}
>> +
>> +	rc = regmap_read(regmap, reg_base + FLASH_SUBTYPE_REG, &val);
>> +	if (rc < 0) {
>> +		dev_err(dev, "Read flash LED 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 LED 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, regmap, chip->r_fields, regs, REG_MAX_COUNT);
>> +	if (rc < 0) {
>> +		dev_err(dev, "Failed to allocate regmap field, 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->priv_data = 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" },
>> +	{ }
>> +};
>> +
>> +MODULE_DEVICE_TABLE(of, qcom_flash_led_match_table);
>> +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");
>> -- 
>> 2.25.1
>>
> 

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