On 4/29/21 2:15 PM, Bjorn Andersson wrote:
> The Light Pulse Generator (LPG) is a PWM-block found in a wide range of
> PMICs from Qualcomm. It can operate on fixed parameters or based on a
> lookup-table, altering the duty cycle over time - which provides the
> means for e.g. hardware assisted transitions of LED brightness.
>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> ---
>
> Changes since v6:
> - Moved code into drivers/leds/rgb/
> - Reverted to earlier qcom,dtest handling to support routing pwm signals
> through dtest lines.
> - Remember the duration of each step of the pattern, rather than adding up and
> then dividing when the value is used.
> - Added missing error prints on DT parse errors.
> - Added sm8150[lb] and made led source and atc presence optional
> - Added missing parenthesis around (len + 1) / 2 in search for hi_pause in the
> pattern.
>
> drivers/leds/Kconfig | 3 +
> drivers/leds/Makefile | 3 +
> drivers/leds/rgb/leds-qcom-lpg.c | 1286 ++++++++++++++++++++++++++++++
> 3 files changed, 1292 insertions(+)
> create mode 100644 drivers/leds/rgb/leds-qcom-lpg.c
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 49d99cb084db..8ab06b3f162d 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -933,6 +933,9 @@ source "drivers/leds/blink/Kconfig"
> comment "Flash and Torch LED drivers"
> source "drivers/leds/flash/Kconfig"
>
> +comment "RGB LED drivers"
> +source "drivers/leds/rgb/Kconfig"
Are you planning to add "drivers/leds/rgb/Kconfig" and "drivers/leds/rgb/Makefile" as a separate change?
> +
> comment "LED Triggers"
> source "drivers/leds/trigger/Kconfig"
>
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index 7e604d3028c8..8cad0465aae0 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -106,6 +106,9 @@ obj-$(CONFIG_LEDS_USER) += uleds.o
> # Flash and Torch LED Drivers
> obj-$(CONFIG_LEDS_CLASS_FLASH) += flash/
>
> +# RGB LED Drivers
> +obj-$(CONFIG_LEDS_CLASS_MULTICOLOR) += rgb/
> +
> # LED Triggers
> obj-$(CONFIG_LEDS_TRIGGERS) += trigger/
>
> diff --git a/drivers/leds/rgb/leds-qcom-lpg.c b/drivers/leds/rgb/leds-qcom-lpg.c
> new file mode 100644
> index 000000000000..c68233b43c2c
> --- /dev/null
> +++ b/drivers/leds/rgb/leds-qcom-lpg.c
> @@ -0,0 +1,1286 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2017-2021 Linaro Ltd
> + * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
> + */
> +#include <linux/bits.h>
> +#include <linux/led-class-multicolor.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/pwm.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +
> +#define LPG_PATTERN_CONFIG_REG 0x40
> +#define LPG_SIZE_CLK_REG 0x41
> +#define LPG_PREDIV_CLK_REG 0x42
> +#define PWM_TYPE_CONFIG_REG 0x43
> +#define PWM_VALUE_REG 0x44
> +#define PWM_ENABLE_CONTROL_REG 0x46
> +#define PWM_SYNC_REG 0x47
> +#define LPG_RAMP_DURATION_REG 0x50
> +#define LPG_HI_PAUSE_REG 0x52
> +#define LPG_LO_PAUSE_REG 0x54
> +#define LPG_HI_IDX_REG 0x56
> +#define LPG_LO_IDX_REG 0x57
> +#define PWM_SEC_ACCESS_REG 0xd0
> +#define PWM_DTEST_REG(x) (0xe2 + (x) - 1)
> +
> +#define TRI_LED_SRC_SEL 0x45
> +#define TRI_LED_EN_CTL 0x46
> +#define TRI_LED_ATC_CTL 0x47
> +
> +#define LPG_LUT_REG(x) (0x40 + (x) * 2)
> +#define RAMP_CONTROL_REG 0xc8
> +
> +struct lpg_channel;
> +struct lpg_data;
> +
> +/**
> + * struct lpg - LPG device context
> + * @dev: struct device for LPG device
> + * @map: regmap for register access
> + * @pwm: PWM-chip object, if operating in PWM mode
> + * @lut_base: base address of the LUT block (optional)
> + * @lut_size: number of entries in the LUT block
> + * @lut_bitmap: allocation bitmap for LUT entries
> + * @triled_base: base address of the TRILED block (optional)
> + * @triled_src: power-source for the TRILED
> + * @triled_has_atc_ctl: true if there is TRI_LED_ATC_CTL register
> + * @triled_has_src_sel: true if there is TRI_LED_SRC_SEL register
> + * @channels: list of PWM channels
> + * @num_channels: number of @channels
> + */
> +struct lpg {
> + struct device *dev;
> + struct regmap *map;
> +
> + struct pwm_chip pwm;
> +
> + const struct lpg_data *data;
> +
> + u32 lut_base;
> + u32 lut_size;
> + unsigned long *lut_bitmap;
> +
> + u32 triled_base;
> + u32 triled_src;
> + bool triled_has_atc_ctl;
> + bool triled_has_src_sel;
> +
> + struct lpg_channel *channels;
> + unsigned int num_channels;
> +};
> +
> +/**
> + * struct lpg_channel - per channel data
> + * @lpg: reference to parent lpg
> + * @base: base address of the PWM channel
> + * @triled_mask: mask in TRILED to enable this channel
> + * @lut_mask: mask in LUT to start pattern generator for this channel
> + * @in_use: channel is exposed to LED framework
> + * @color: color of the LED attached to this channel
> + * @dtest_line: DTEST line for output, or 0 if disabled
> + * @dtest_value: DTEST line configuration
> + * @pwm_value: duty (in microseconds) of the generated pulses, overridden by LUT
> + * @enabled: output enabled?
> + * @period_us: period (in microseconds) of the generated pulses
> + * @pwm_size: resolution of the @pwm_value, 6 or 9 bits
> + * @clk: base frequency of the clock generator
> + * @pre_div: divider of @clk
> + * @pre_div_exp: exponential divider of @clk
> + * @ramp_enabled: duty cycle is driven by iterating over lookup table
> + * @ramp_ping_pong: reverse through pattern, rather than wrapping to start
> + * @ramp_oneshot: perform only a single pass over the pattern
> + * @ramp_reverse: iterate over pattern backwards
> + * @ramp_tick_ms: length (in milliseconds) of one step in the pattern
> + * @ramp_lo_pause_ms: pause (in milliseconds) before iterating over pattern
> + * @ramp_hi_pause_ms: pause (in milliseconds) after iterating over pattern
> + * @pattern_lo_idx: start index of associated pattern
> + * @pattern_hi_idx: last index of associated pattern
> + */
> +struct lpg_channel {
> + struct lpg *lpg;
> +
> + u32 base;
> + unsigned int triled_mask;
> + unsigned int lut_mask;
> +
> + bool in_use;
> +
> + int color;
> +
> + u32 dtest_line;
> + u32 dtest_value;
> +
> + u16 pwm_value;
> + bool enabled;
> +
> + unsigned int period_us;
> + unsigned int pwm_size;
> + unsigned int clk;
> + unsigned int pre_div;
> + unsigned int pre_div_exp;
> +
> + bool ramp_enabled;
> + bool ramp_ping_pong;
> + bool ramp_oneshot;
> + bool ramp_reverse;
> + unsigned long ramp_tick_ms;
> + unsigned long ramp_lo_pause_ms;
> + unsigned long ramp_hi_pause_ms;
> +
> + unsigned int pattern_lo_idx;
> + unsigned int pattern_hi_idx;
> +};
> +
> +/**
> + * struct lpg_led - logical LED object
> + * @lpg: lpg context reference
> + * @cdev: LED class device
> + * @mcdev: Multicolor LED class device
> + * @num_channels: number of @channels
> + * @channels: list of channels associated with the LED
> + */
> +struct lpg_led {
> + struct lpg *lpg;
> +
> + struct led_classdev cdev;
> + struct led_classdev_mc mcdev;
> +
> + unsigned int num_channels;
> + struct lpg_channel *channels[];
> +};
> +
> +/**
> + * struct lpg_channel_data - per channel initialization data
> + * @base: base address for PWM channel registers
> + * @triled_mask: bitmask for controlling this channel in TRILED
> + */
> +struct lpg_channel_data {
> + unsigned int base;
> + u8 triled_mask;
> +};
> +
> +/**
> + * struct lpg_data - initialization data
> + * @lut_base: base address of LUT block
> + * @lut_size: number of entries in LUT
> + * @triled_base: base address of TRILED
> + * @triled_has_atc_ctl: true if there is TRI_LED_ATC_CTL register
> + * @triled_has_src_sel: true if there is TRI_LED_SRC_SEL register
> + * @pwm_9bit_mask: bitmask for switching from 6bit to 9bit pwm
> + * @num_channels: number of channels in LPG
> + * @channels: list of channel initialization data
> + */
> +struct lpg_data {
> + unsigned int lut_base;
> + unsigned int lut_size;
> + unsigned int triled_base;
> + bool triled_has_atc_ctl;
> + bool triled_has_src_sel;
> + unsigned int pwm_9bit_mask;
> + int num_channels;
> + struct lpg_channel_data *channels;
> +};
> +
> +static int triled_set(struct lpg *lpg, unsigned int mask, unsigned int enable)
> +{
> + /* Skip if we don't have a triled block */
> + if (!lpg->triled_base)
> + return 0;
> +
> + return regmap_update_bits(lpg->map, lpg->triled_base + TRI_LED_EN_CTL,
> + mask, enable);
> +}
> +
> +static int lpg_lut_store(struct lpg *lpg, struct led_pattern *pattern,
> + size_t len, unsigned int *lo_idx, unsigned int *hi_idx)
> +{
> + unsigned int idx;
> + u16 val;
> + int i;
> +
> + /* Hardware does not behave when LO_IDX == HI_IDX */
> + if (len == 1)
> + return -EINVAL;
> +
> + idx = bitmap_find_next_zero_area(lpg->lut_bitmap, lpg->lut_size,
> + 0, len, 0);
> + if (idx >= lpg->lut_size)
> + return -ENOMEM;
> +
> + for (i = 0; i < len; i++) {
> + val = pattern[i].brightness;
> +
> + regmap_bulk_write(lpg->map, lpg->lut_base + LPG_LUT_REG(idx + i), &val, 1);
> + }
> +
> + bitmap_set(lpg->lut_bitmap, idx, len);
> +
> + *lo_idx = idx;
> + *hi_idx = idx + len - 1;
> +
> + return 0;
> +}
> +
> +static void lpg_lut_free(struct lpg *lpg, unsigned int lo_idx, unsigned int hi_idx)
> +{
> + int len;
> +
> + if (lo_idx == hi_idx)
> + return;
> +
> + len = hi_idx - lo_idx + 1;
> + bitmap_clear(lpg->lut_bitmap, lo_idx, len);
> +}
> +
> +static int lpg_lut_sync(struct lpg *lpg, unsigned int mask)
> +{
> + return regmap_write(lpg->map, lpg->lut_base + RAMP_CONTROL_REG, mask);
> +}
> +
> +#define NUM_PWM_PREDIV 4
> +#define NUM_PWM_CLK 3
> +#define NUM_EXP 7
> +
> +static const unsigned int lpg_clk_table[NUM_PWM_PREDIV][NUM_PWM_CLK] = {
> + {
> + 1 * (NSEC_PER_SEC / 1024),
> + 1 * (NSEC_PER_SEC / 32768),
> + 1 * (NSEC_PER_SEC / 19200000),
> + },
> + {
> + 3 * (NSEC_PER_SEC / 1024),
> + 3 * (NSEC_PER_SEC / 32768),
> + 3 * (NSEC_PER_SEC / 19200000),
> + },
> + {
> + 5 * (NSEC_PER_SEC / 1024),
> + 5 * (NSEC_PER_SEC / 32768),
> + 5 * (NSEC_PER_SEC / 19200000),
> + },
> + {
> + 6 * (NSEC_PER_SEC / 1024),
> + 6 * (NSEC_PER_SEC / 32768),
> + 6 * (NSEC_PER_SEC / 19200000),
> + },
> +};
> +
> +/*
> + * PWM Frequency = Clock Frequency / (N * T)
> + * or
> + * PWM Period = Clock Period * (N * T)
> + * where
> + * N = 2^9 or 2^6 for 9-bit or 6-bit PWM size
> + * T = Pre-divide * 2^m, where m = 0..7 (exponent)
> + *
> + * This is the formula to figure out m for the best pre-divide and clock:
> + * (PWM Period / N) = (Pre-divide * Clock Period) * 2^m
> + */
> +static void lpg_calc_freq(struct lpg_channel *chan, unsigned int period_us)
> +{
> + int n, m, clk, div;
> + int best_m, best_div, best_clk;
> + unsigned int last_err, cur_err, min_err;
> + unsigned int tmp_p, period_n;
> +
> + if (period_us == chan->period_us)
> + return;
> +
> + /* PWM Period / N */
> + if (period_us < UINT_MAX / NSEC_PER_USEC)
> + n = 6;
> + else
> + n = 9;
> +
> + period_n = ((u64)period_us * NSEC_PER_USEC) >> n;
> +
> + min_err = UINT_MAX;
> + last_err = UINT_MAX;
> + best_m = 0;
> + best_clk = 0;
> + best_div = 0;
> + for (clk = 0; clk < NUM_PWM_CLK; clk++) {
> + for (div = 0; div < NUM_PWM_PREDIV; div++) {
> + /* period_n = (PWM Period / N) */
> + /* tmp_p = (Pre-divide * Clock Period) * 2^m */
> + tmp_p = lpg_clk_table[div][clk];
> + for (m = 0; m <= NUM_EXP; m++) {
> + cur_err = abs(period_n - tmp_p);
> + if (cur_err < min_err) {
> + min_err = cur_err;
> + best_m = m;
> + best_clk = clk;
> + best_div = div;
> + }
> +
> + if (m && cur_err > last_err)
> + /* Break for bigger cur_err */
> + break;
> +
> + last_err = cur_err;
> + tmp_p <<= 1;
> + }
> + }
> + }
> +
> + /* Use higher resolution */
> + if (best_m >= 3 && n == 6) {
> + n += 3;
> + best_m -= 3;
> + }
> +
> + chan->clk = best_clk;
> + chan->pre_div = best_div;
> + chan->pre_div_exp = best_m;
> + chan->pwm_size = n;
> +
> + chan->period_us = period_us;
> +}
> +
> +static void lpg_calc_duty(struct lpg_channel *chan, unsigned int duty_us)
> +{
> + unsigned int max = (1 << chan->pwm_size) - 1;
> + unsigned int val = div_u64((u64)duty_us << chan->pwm_size, chan->period_us);
> +
> + chan->pwm_value = min(val, max);
> +}
> +
> +static void lpg_apply_freq(struct lpg_channel *chan)
> +{
> + unsigned long val;
> + struct lpg *lpg = chan->lpg;
> +
> + if (!chan->enabled)
> + return;
> +
> + /* Clock register values are off-by-one from lpg_clk_table */
> + val = chan->clk + 1;
> +
> + if (chan->pwm_size == 9)
> + val |= lpg->data->pwm_9bit_mask;
> +
> + regmap_write(lpg->map, chan->base + LPG_SIZE_CLK_REG, val);
> +
> + val = chan->pre_div << 5 | chan->pre_div_exp;
> + regmap_write(lpg->map, chan->base + LPG_PREDIV_CLK_REG, val);
> +}
> +
> +#define LPG_ENABLE_GLITCH_REMOVAL BIT(5)
> +
> +static void lpg_enable_glitch(struct lpg_channel *chan)
> +{
> + struct lpg *lpg = chan->lpg;
> +
> + regmap_update_bits(lpg->map, chan->base + PWM_TYPE_CONFIG_REG,
> + LPG_ENABLE_GLITCH_REMOVAL, 0);
> +}
> +
> +static void lpg_disable_glitch(struct lpg_channel *chan)
> +{
> + struct lpg *lpg = chan->lpg;
> +
> + regmap_update_bits(lpg->map, chan->base + PWM_TYPE_CONFIG_REG,
> + LPG_ENABLE_GLITCH_REMOVAL,
> + LPG_ENABLE_GLITCH_REMOVAL);
> +}
> +
> +static void lpg_apply_pwm_value(struct lpg_channel *chan)
> +{
> + struct lpg *lpg = chan->lpg;
> + u16 val = chan->pwm_value;
> +
> + if (!chan->enabled)
> + return;
> +
> + regmap_bulk_write(lpg->map, chan->base + PWM_VALUE_REG, &val, 1);
> +}
> +
> +#define LPG_PATTERN_CONFIG_LO_TO_HI BIT(4)
> +#define LPG_PATTERN_CONFIG_REPEAT BIT(3)
> +#define LPG_PATTERN_CONFIG_TOGGLE BIT(2)
> +#define LPG_PATTERN_CONFIG_PAUSE_HI BIT(1)
> +#define LPG_PATTERN_CONFIG_PAUSE_LO BIT(0)
> +
> +static void lpg_apply_lut_control(struct lpg_channel *chan)
> +{
> + struct lpg *lpg = chan->lpg;
> + unsigned int hi_pause;
> + unsigned int lo_pause;
> + unsigned int step;
> + unsigned int conf = 0;
> + unsigned int lo_idx = chan->pattern_lo_idx;
> + unsigned int hi_idx = chan->pattern_hi_idx;
> + int pattern_len;
> +
> + if (!chan->ramp_enabled || chan->pattern_lo_idx == chan->pattern_hi_idx)
> + return;
> +
> + pattern_len = hi_idx - lo_idx + 1;
> +
> + step = chan->ramp_tick_ms;
> + hi_pause = DIV_ROUND_UP(chan->ramp_hi_pause_ms, step);
> + lo_pause = DIV_ROUND_UP(chan->ramp_lo_pause_ms, step);
> +
> + if (!chan->ramp_reverse)
> + conf |= LPG_PATTERN_CONFIG_LO_TO_HI;
> + if (!chan->ramp_oneshot)
> + conf |= LPG_PATTERN_CONFIG_REPEAT;
> + if (chan->ramp_ping_pong)
> + conf |= LPG_PATTERN_CONFIG_TOGGLE;
> + if (chan->ramp_hi_pause_ms)
> + conf |= LPG_PATTERN_CONFIG_PAUSE_HI;
> + if (chan->ramp_lo_pause_ms)
> + conf |= LPG_PATTERN_CONFIG_PAUSE_LO;
> +
> + regmap_write(lpg->map, chan->base + LPG_PATTERN_CONFIG_REG, conf);
> + regmap_write(lpg->map, chan->base + LPG_HI_IDX_REG, hi_idx);
> + regmap_write(lpg->map, chan->base + LPG_LO_IDX_REG, lo_idx);
> +
> + regmap_write(lpg->map, chan->base + LPG_RAMP_DURATION_REG, step);
> + regmap_write(lpg->map, chan->base + LPG_HI_PAUSE_REG, hi_pause);
> + regmap_write(lpg->map, chan->base + LPG_LO_PAUSE_REG, lo_pause);
> +}
> +
> +#define LPG_ENABLE_CONTROL_OUTPUT BIT(7)
> +#define LPG_ENABLE_CONTROL_BUFFER_TRISTATE BIT(5)
> +#define LPG_ENABLE_CONTROL_SRC_PWM BIT(2)
> +#define LPG_ENABLE_CONTROL_RAMP_GEN BIT(1)
> +
> +static void lpg_apply_control(struct lpg_channel *chan)
> +{
> + unsigned int ctrl;
> + struct lpg *lpg = chan->lpg;
> +
> + ctrl = LPG_ENABLE_CONTROL_BUFFER_TRISTATE;
> +
> + if (chan->enabled)
> + ctrl |= LPG_ENABLE_CONTROL_OUTPUT;
> +
> + if (chan->pattern_lo_idx != chan->pattern_hi_idx)
> + ctrl |= LPG_ENABLE_CONTROL_RAMP_GEN;
> + else
> + ctrl |= LPG_ENABLE_CONTROL_SRC_PWM;
> +
> + regmap_write(lpg->map, chan->base + PWM_ENABLE_CONTROL_REG, ctrl);
> +
> + /*
> + * Due to LPG hardware bug, in the PWM mode, having enabled PWM,
> + * We have to write PWM values one more time.
> + */
> + if (chan->enabled)
> + lpg_apply_pwm_value(chan);
> +}
> +
> +#define LPG_SYNC_PWM BIT(0)
> +
> +static void lpg_apply_sync(struct lpg_channel *chan)
> +{
> + struct lpg *lpg = chan->lpg;
> +
> + regmap_write(lpg->map, chan->base + PWM_SYNC_REG, LPG_SYNC_PWM);
> +}
> +
> +static int lpg_parse_dtest(struct lpg *lpg)
> +{
> + struct lpg_channel *chan;
> + struct device_node *np = lpg->dev->of_node;
> + int count;
> + int ret;
> + int i;
> +
> + count = of_property_count_u32_elems(np, "qcom,dtest");
> + if (count == -EINVAL) {
> + return 0;
> + } else if (count < 0) {
> + ret = count;
> + goto err_malformed;
> + } else if (count != lpg->data->num_channels * 2) {
> + dev_err(lpg->dev, "qcom,dtest needs to be %d items\n",
> + lpg->data->num_channels * 2);
> + return -EINVAL;
> + }
> +
> + for (i = 0; i < lpg->data->num_channels; i++) {
> + chan = &lpg->channels[i];
> +
> + ret = of_property_read_u32_index(np, "qcom,dtest", i * 2,
> + &chan->dtest_line);
> + if (ret)
> + goto err_malformed;
> +
> + ret = of_property_read_u32_index(np, "qcom,dtest", i * 2 + 1,
> + &chan->dtest_value);
> + if (ret)
> + goto err_malformed;
> + }
> +
> + return 0;
> +
> +err_malformed:
> + dev_err(lpg->dev, "malformed qcom,dtest\n");
> + return ret;
> +}
> +
> +static void lpg_apply_dtest(struct lpg_channel *chan)
> +{
> + struct lpg *lpg = chan->lpg;
> +
> + if (!chan->dtest_line)
> + return;
> +
> + regmap_write(lpg->map, chan->base + PWM_SEC_ACCESS_REG, 0xa5);
> + regmap_write(lpg->map, chan->base + PWM_DTEST_REG(chan->dtest_line),
> + chan->dtest_value);
> +}
> +
> +static void lpg_apply(struct lpg_channel *chan)
> +{
> + lpg_disable_glitch(chan);
> + lpg_apply_freq(chan);
> + lpg_apply_pwm_value(chan);
> + lpg_apply_control(chan);
> + lpg_apply_sync(chan);
> + lpg_apply_lut_control(chan);
> + lpg_enable_glitch(chan);
> +}
> +
> +static void lpg_brightness_set(struct lpg_led *led, struct led_classdev *cdev,
> + struct mc_subled *subleds)
> +{
> + enum led_brightness brightness;
> + struct lpg_channel *chan;
> + unsigned int triled_enabled = 0;
> + unsigned int triled_mask = 0;
> + unsigned int lut_mask = 0;
> + unsigned int duty_us;
> + struct lpg *lpg = led->lpg;
> + int i;
> +
> + for (i = 0; i < led->num_channels; i++) {
> + chan = led->channels[i];
> + brightness = subleds[i].brightness;
> +
> + if (brightness == LED_OFF) {
> + chan->enabled = false;
> + chan->ramp_enabled = false;
> + } else if (chan->pattern_lo_idx != chan->pattern_hi_idx) {
> + lpg_calc_freq(chan, NSEC_PER_USEC);
> +
> + chan->enabled = true;
> + chan->ramp_enabled = true;
> +
> + lut_mask |= chan->lut_mask;
> + triled_enabled |= chan->triled_mask;
> + } else {
> + lpg_calc_freq(chan, NSEC_PER_USEC);
> +
> + duty_us = brightness * chan->period_us / cdev->max_brightness;
> + lpg_calc_duty(chan, duty_us);
> + chan->enabled = true;
> + chan->ramp_enabled = false;
> +
> + triled_enabled |= chan->triled_mask;
> + }
> +
> + triled_mask |= chan->triled_mask;
> +
> + lpg_apply(chan);
> + }
> +
> + /* Toggle triled lines */
> + if (triled_mask)
> + triled_set(lpg, triled_mask, triled_enabled);
> +
> + /* Trigger start of ramp generator(s) */
> + if (lut_mask)
> + lpg_lut_sync(lpg, lut_mask);
> +}
> +
> +static void lpg_brightness_single_set(struct led_classdev *cdev,
> + enum led_brightness value)
> +{
> + struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
> + struct mc_subled info;
> +
> + info.brightness = value;
> + lpg_brightness_set(led, cdev, &info);
> +}
> +
> +static void lpg_brightness_mc_set(struct led_classdev *cdev,
> + enum led_brightness value)
> +{
> + struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
> + struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
> +
> + led_mc_calc_color_components(mc, value);
> + lpg_brightness_set(led, cdev, mc->subled_info);
> +}
> +
> +static int lpg_blink_set(struct lpg_led *led,
> + unsigned long *delay_on, unsigned long *delay_off)
> +{
> + struct lpg_channel *chan;
> + unsigned int period_us;
> + unsigned int duty_us;
> + int i;
> +
> + if (!*delay_on && !*delay_off) {
> + *delay_on = 500;
> + *delay_off = 500;
> + }
> +
> + duty_us = *delay_on * USEC_PER_MSEC;
> + period_us = (*delay_on + *delay_off) * USEC_PER_MSEC;
> +
> + for (i = 0; i < led->num_channels; i++) {
> + chan = led->channels[i];
> +
> + lpg_calc_freq(chan, period_us);
> + lpg_calc_duty(chan, duty_us);
> +
> + chan->enabled = true;
> + chan->ramp_enabled = false;
> +
> + lpg_apply(chan);
> + }
> +
> + return 0;
> +}
> +
> +static int lpg_blink_single_set(struct led_classdev *cdev,
> + unsigned long *delay_on, unsigned long *delay_off)
> +{
> + struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
> +
> + return lpg_blink_set(led, delay_on, delay_off);
> +}
> +
> +static int lpg_blink_mc_set(struct led_classdev *cdev,
> + unsigned long *delay_on, unsigned long *delay_off)
> +{
> + struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
> + struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
> +
> + return lpg_blink_set(led, delay_on, delay_off);
> +}
> +
> +static int lpg_pattern_set(struct lpg_led *led, struct led_pattern *pattern,
> + u32 len, int repeat)
> +{
> + struct lpg_channel *chan;
> + struct lpg *lpg = led->lpg;
> + unsigned int hi_pause;
> + unsigned int lo_pause;
> + unsigned int lo_idx;
> + unsigned int hi_idx;
> + bool ping_pong = true;
> + int brightness_a;
> + int brightness_b;
> + int ret;
> + int i;
> +
> + /* Only support oneshot or indefinite loops, due to limited pattern space */
> + if (repeat != -1 && repeat != 1)
> + return -EINVAL;
> +
> + /*
> + * The LPG plays patterns with at a fixed pace, a "low pause" can be
> + * performed before the pattern and a "high pause" after. In order to
> + * save space the pattern can be played in "ping pong" mode, in which
> + * the pattern is first played forward, then "high pause" is applied,
> + * then the pattern is played backwards and finally the "low pause" is
> + * applied.
> + *
> + * The delta_t of the first entry is used to determine the pace of the
> + * pattern.
> + *
> + * If the specified pattern is a palindrome the ping pong mode is
> + * enabled. In this scenario the delta_t of the last entry determines
> + * the "low pause" time and the delta_t of the middle entry (i.e. the
> + * last in the programmed pattern) determines the "high pause". If the
> + * pattern consists of an odd number of values, no "high pause" is
> + * used.
> + *
> + * When ping pong mode is not selected, the delta_t of the last entry
> + * is used as "high pause". No "low pause" is used.
> + *
> + * delta_t of any other members of the pattern is ignored.
> + */
> +
> + /* Detect palindromes and use "ping pong" to reduce LUT usage */
> + for (i = 0; i < len / 2; i++) {
> + brightness_a = pattern[i].brightness;
> + brightness_b = pattern[len - i - 1].brightness;
> +
> + if (brightness_a != brightness_b) {
> + ping_pong = false;
> + break;
> + }
> + }
> +
> + if (ping_pong) {
> + if (len % 2)
> + hi_pause = 0;
> + else
> + hi_pause = pattern[(len + 1) / 2].delta_t;
> + lo_pause = pattern[len - 1].delta_t;
> +
> + len = (len + 1) / 2;
> + } else {
> + hi_pause = pattern[len - 1].delta_t;
> + lo_pause = 0;
> + }
> +
> + ret = lpg_lut_store(lpg, pattern, len, &lo_idx, &hi_idx);
> + if (ret < 0)
> + return ret;
> +
> + for (i = 0; i < led->num_channels; i++) {
> + chan = led->channels[i];
> +
> + chan->ramp_tick_ms = pattern[0].delta_t;
> + chan->ramp_ping_pong = ping_pong;
> + chan->ramp_oneshot = repeat != -1;
> +
> + chan->ramp_lo_pause_ms = lo_pause;
> + chan->ramp_hi_pause_ms = hi_pause;
> +
> + chan->pattern_lo_idx = lo_idx;
> + chan->pattern_hi_idx = hi_idx;
> + }
> +
> + return 0;
> +}
> +
> +static int lpg_pattern_single_set(struct led_classdev *cdev,
> + struct led_pattern *pattern, u32 len,
> + int repeat)
> +{
> + struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
> + int ret;
> +
> + ret = lpg_pattern_set(led, pattern, len, repeat);
> + if (ret < 0)
> + return ret;
> +
> + lpg_brightness_single_set(cdev, LED_FULL);
> +
> + return 0;
> +}
> +
> +static int lpg_pattern_mc_set(struct led_classdev *cdev,
> + struct led_pattern *pattern, u32 len,
> + int repeat)
> +{
> + struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
> + struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
> + int ret;
> +
> + ret = lpg_pattern_set(led, pattern, len, repeat);
> + if (ret < 0)
> + return ret;
> +
> + led_mc_calc_color_components(mc, LED_FULL);
> + lpg_brightness_set(led, cdev, mc->subled_info);
> +
> + return 0;
> +}
> +
> +static int lpg_pattern_clear(struct lpg_led *led)
> +{
> + struct lpg_channel *chan;
> + struct lpg *lpg = led->lpg;
> + int i;
> +
> + chan = led->channels[0];
> + lpg_lut_free(lpg, chan->pattern_lo_idx, chan->pattern_hi_idx);
> +
> + for (i = 0; i < led->num_channels; i++) {
> + chan = led->channels[i];
> + chan->pattern_lo_idx = 0;
> + chan->pattern_hi_idx = 0;
> + }
> +
> + return 0;
> +}
> +
> +static int lpg_pattern_single_clear(struct led_classdev *cdev)
> +{
> + struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
> +
> + return lpg_pattern_clear(led);
> +}
> +
> +static int lpg_pattern_mc_clear(struct led_classdev *cdev)
> +{
> + struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
> + struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
> +
> + return lpg_pattern_clear(led);
> +}
> +
> +static int lpg_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
> +{
> + struct lpg *lpg = container_of(chip, struct lpg, pwm);
> + struct lpg_channel *chan = &lpg->channels[pwm->hwpwm];
> +
> + return chan->in_use ? -EBUSY : 0;
> +}
> +
> +static int lpg_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> + const struct pwm_state *state)
> +{
> + struct lpg *lpg = container_of(chip, struct lpg, pwm);
> + struct lpg_channel *chan = &lpg->channels[pwm->hwpwm];
> +
> + lpg_calc_freq(chan, div_u64(state->period, NSEC_PER_USEC));
> + lpg_calc_duty(chan, div_u64(state->duty_cycle, NSEC_PER_USEC));
> + chan->enabled = state->enabled;
> +
> + lpg_apply(chan);
> +
> + triled_set(lpg, chan->triled_mask, chan->enabled ? chan->triled_mask : 0);
> +
> + return 0;
> +}
> +
> +static const struct pwm_ops lpg_pwm_ops = {
> + .request = lpg_pwm_request,
> + .apply = lpg_pwm_apply,
> + .owner = THIS_MODULE,
> +};
> +
> +static int lpg_add_pwm(struct lpg *lpg)
> +{
> + int ret;
> +
> + lpg->pwm.base = -1;
> + lpg->pwm.dev = lpg->dev;
> + lpg->pwm.npwm = lpg->num_channels;
> + lpg->pwm.ops = &lpg_pwm_ops;
> +
> + ret = pwmchip_add(&lpg->pwm);
> + if (ret)
> + dev_err(lpg->dev, "failed to add PWM chip: ret %d\n", ret);
> +
> + return ret;
> +}
> +
> +static int lpg_parse_channel(struct lpg *lpg, struct device_node *np,
> + struct lpg_channel **channel)
> +{
> + struct lpg_channel *chan;
> + u32 color = LED_COLOR_ID_GREEN;
> + u32 reg;
> + int ret;
> +
> + ret = of_property_read_u32(np, "reg", ®);
> + if (ret || !reg || reg > lpg->num_channels) {
> + dev_err(lpg->dev, "invalid reg of %pOFn\n", np);
> + return -EINVAL;
> + }
> +
> + chan = &lpg->channels[reg - 1];
> + chan->in_use = true;
> +
> + ret = of_property_read_u32(np, "color", &color);
> + if (ret < 0 && ret != -EINVAL) {
> + dev_err(lpg->dev, "failed to parse \"color\" of %pOF\n", np);
> + return ret;
> + }
> +
> + chan->color = color;
> +
> + *channel = chan;
> +
> + return 0;
> +}
> +
> +static int lpg_add_led(struct lpg *lpg, struct device_node *np)
> +{
> + struct led_classdev *cdev;
> + struct device_node *child;
> + struct mc_subled *info;
> + struct lpg_led *led;
> + const char *state;
> + int num_channels;
> + u32 color = 0;
> + int ret;
> + int i;
> +
> + ret = of_property_read_u32(np, "color", &color);
> + if (ret < 0 && ret != -EINVAL) {
> + dev_err(lpg->dev, "failed to parse \"color\" of %pOF\n", np);
> + return ret;
> + }
> +
> + if (color == LED_COLOR_ID_MULTI)
> + num_channels = of_get_available_child_count(np);
> + else
> + num_channels = 1;
> +
> + led = devm_kzalloc(lpg->dev, struct_size(led, channels, num_channels), GFP_KERNEL);
> + if (!led)
> + return -ENOMEM;
> +
> + led->lpg = lpg;
> + led->num_channels = num_channels;
> +
> + if (color == LED_COLOR_ID_MULTI) {
> + info = devm_kcalloc(lpg->dev, num_channels, sizeof(*info), GFP_KERNEL);
> + if (!info)
> + return -ENOMEM;
> + i = 0;
> + for_each_available_child_of_node(np, child) {
> + ret = lpg_parse_channel(lpg, child, &led->channels[i]);
> + if (ret < 0)
> + return ret;
> +
> + info[i].color_index = led->channels[i]->color;
> + info[i].intensity = LED_FULL;
> + i++;
> + }
> +
> + led->mcdev.subled_info = info;
> + led->mcdev.num_colors = num_channels;
> +
> + cdev = &led->mcdev.led_cdev;
> + cdev->brightness_set = lpg_brightness_mc_set;
> + cdev->blink_set = lpg_blink_mc_set;
> +
> + /* Register pattern accessors only if we have a LUT block */
> + if (lpg->lut_base) {
> + cdev->pattern_set = lpg_pattern_mc_set;
> + cdev->pattern_clear = lpg_pattern_mc_clear;
> + }
> + } else {
> + ret = lpg_parse_channel(lpg, np, &led->channels[0]);
> + if (ret < 0)
> + return ret;
> +
> + cdev = &led->cdev;
> + cdev->brightness_set = lpg_brightness_single_set;
> + cdev->blink_set = lpg_blink_single_set;
> +
> + /* Register pattern accessors only if we have a LUT block */
> + if (lpg->lut_base) {
> + cdev->pattern_set = lpg_pattern_single_set;
> + cdev->pattern_clear = lpg_pattern_single_clear;
> + }
> + }
> +
> + /* Use label else node name */
> + cdev->name = of_get_property(np, "label", NULL) ? : np->name;
> + cdev->default_trigger = of_get_property(np, "linux,default-trigger", NULL);
> + cdev->max_brightness = 255;
> +
> + if (!of_property_read_string(np, "default-state", &state) &&
> + !strcmp(state, "on"))
> + cdev->brightness = LED_FULL;
> + else
> + cdev->brightness = LED_OFF;
> +
> + cdev->brightness_set(cdev, cdev->brightness);
> +
> + if (color == LED_COLOR_ID_MULTI)
> + ret = devm_led_classdev_multicolor_register(lpg->dev, &led->mcdev);
> + else
> + ret = devm_led_classdev_register(lpg->dev, &led->cdev);
> + if (ret)
> + dev_err(lpg->dev, "unable to register %s\n", cdev->name);
> +
> + return ret;
> +}
> +
> +static int lpg_init_channels(struct lpg *lpg)
> +{
> + const struct lpg_data *data = lpg->data;
> + int i;
> +
> + lpg->num_channels = data->num_channels;
> + lpg->channels = devm_kcalloc(lpg->dev, data->num_channels,
> + sizeof(struct lpg_channel), GFP_KERNEL);
> + if (!lpg->channels)
> + return -ENOMEM;
> +
> + for (i = 0; i < data->num_channels; i++) {
> + lpg->channels[i].lpg = lpg;
> + lpg->channels[i].base = data->channels[i].base;
> + lpg->channels[i].triled_mask = data->channels[i].triled_mask;
> + lpg->channels[i].lut_mask = BIT(i);
> + }
> +
> + return 0;
> +}
> +
> +static int lpg_init_triled(struct lpg *lpg)
> +{
> + struct device_node *np = lpg->dev->of_node;
> + int ret;
> +
> + /* Skip initialization if we don't have a triled block */
> + if (!lpg->data->triled_base)
> + return 0;
> +
> + lpg->triled_base = lpg->data->triled_base;
> + lpg->triled_has_atc_ctl = lpg->data->triled_has_atc_ctl;
> + lpg->triled_has_src_sel = lpg->data->triled_has_src_sel;
> +
> + if (lpg->triled_has_src_sel) {
> + ret = of_property_read_u32(np, "qcom,power-source", &lpg->triled_src);
> + if (ret || lpg->triled_src == 2 || lpg->triled_src > 3) {
> + dev_err(lpg->dev, "invalid power source\n");
> + return -EINVAL;
> + }
> + }
> +
> + /* Disable automatic trickle charge LED */
> + if (lpg->triled_has_atc_ctl)
> + regmap_write(lpg->map, lpg->triled_base + TRI_LED_ATC_CTL, 0);
> +
> + /* Configure power source */
> + if (lpg->triled_has_src_sel)
> + regmap_write(lpg->map, lpg->triled_base + TRI_LED_SRC_SEL, lpg->triled_src);
> +
> + /* Default all outputs to off */
> + regmap_write(lpg->map, lpg->triled_base + TRI_LED_EN_CTL, 0);
> +
> + return 0;
> +}
> +
> +static int lpg_init_lut(struct lpg *lpg)
> +{
> + const struct lpg_data *data = lpg->data;
> + size_t bitmap_size;
> +
> + if (!data->lut_base)
> + return 0;
> +
> + lpg->lut_base = data->lut_base;
> + lpg->lut_size = data->lut_size;
> +
> + bitmap_size = BITS_TO_BYTES(lpg->lut_size);
> + lpg->lut_bitmap = devm_kzalloc(lpg->dev, bitmap_size, GFP_KERNEL);
> + if (!lpg->lut_bitmap)
> + return -ENOMEM;
> +
> + bitmap_clear(lpg->lut_bitmap, 0, lpg->lut_size);
> +
> + return 0;
> +}
> +
> +static int lpg_probe(struct platform_device *pdev)
> +{
> + struct device_node *np;
> + struct lpg *lpg;
> + int ret;
> + int i;
> +
> + lpg = devm_kzalloc(&pdev->dev, sizeof(*lpg), GFP_KERNEL);
> + if (!lpg)
> + return -ENOMEM;
> +
> + lpg->data = of_device_get_match_data(&pdev->dev);
> + if (!lpg->data)
> + return -EINVAL;
> +
> + lpg->dev = &pdev->dev;
> +
> + lpg->map = dev_get_regmap(pdev->dev.parent, NULL);
> + if (!lpg->map) {
> + dev_err(&pdev->dev, "parent regmap unavailable\n");
> + return -ENXIO;
> + }
> +
> + ret = lpg_init_channels(lpg);
> + if (ret < 0)
> + return ret;
> +
> + ret = lpg_parse_dtest(lpg);
> + if (ret < 0)
> + return ret;
> +
> + ret = lpg_init_triled(lpg);
> + if (ret < 0)
> + return ret;
> +
> + ret = lpg_init_lut(lpg);
> + if (ret < 0)
> + return ret;
> +
> + for_each_available_child_of_node(pdev->dev.of_node, np) {
> + ret = lpg_add_led(lpg, np);
> + if (ret)
> + return ret;
> + }
> +
> + for (i = 0; i < lpg->num_channels; i++)
> + lpg_apply_dtest(&lpg->channels[i]);
> +
> + ret = lpg_add_pwm(lpg);
> + if (ret)
> + return ret;
> +
> + platform_set_drvdata(pdev, lpg);
> +
> + return 0;
> +}
> +
> +static int lpg_remove(struct platform_device *pdev)
> +{
> + struct lpg *lpg = platform_get_drvdata(pdev);
> +
> + pwmchip_remove(&lpg->pwm);
> +
> + return 0;
> +}
> +
> +static const struct lpg_data pm8916_pwm_data = {
> + .pwm_9bit_mask = BIT(2),
> +
> + .num_channels = 1,
> + .channels = (struct lpg_channel_data[]) {
> + { .base = 0xbc00 },
> + },
> +};
> +
> +static const struct lpg_data pm8941_lpg_data = {
> + .lut_base = 0xb000,
> + .lut_size = 64,
> +
> + .triled_base = 0xd000,
> + .triled_has_atc_ctl = true,
> + .triled_has_src_sel = true,
> +
> + .pwm_9bit_mask = 3 << 4,
> +
> + .num_channels = 8,
> + .channels = (struct lpg_channel_data[]) {
> + { .base = 0xb100 },
> + { .base = 0xb200 },
> + { .base = 0xb300 },
> + { .base = 0xb400 },
> + { .base = 0xb500, .triled_mask = BIT(5) },
> + { .base = 0xb600, .triled_mask = BIT(6) },
> + { .base = 0xb700, .triled_mask = BIT(7) },
> + { .base = 0xb800 },
> + },
> +};
> +
> +static const struct lpg_data pm8994_lpg_data = {
> + .lut_base = 0xb000,
> + .lut_size = 64,
> +
> + .pwm_9bit_mask = 3 << 4,
> +
> + .num_channels = 6,
> + .channels = (struct lpg_channel_data[]) {
> + { .base = 0xb100 },
> + { .base = 0xb200 },
> + { .base = 0xb300 },
> + { .base = 0xb400 },
> + { .base = 0xb500 },
> + { .base = 0xb600 },
> + },
> +};
> +
> +static const struct lpg_data pmi8994_lpg_data = {
> + .lut_base = 0xb000,
> + .lut_size = 24,
> +
> + .triled_base = 0xd000,
> + .triled_has_atc_ctl = true,
> + .triled_has_src_sel = true,
> +
> + .pwm_9bit_mask = BIT(4),
> +
> + .num_channels = 4,
> + .channels = (struct lpg_channel_data[]) {
> + { .base = 0xb100, .triled_mask = BIT(5) },
> + { .base = 0xb200, .triled_mask = BIT(6) },
> + { .base = 0xb300, .triled_mask = BIT(7) },
> + { .base = 0xb400 },
> + },
> +};
> +
> +static const struct lpg_data pmi8998_lpg_data = {
> + .lut_base = 0xb000,
> + .lut_size = 49,
> +
> + .triled_base = 0xd000,
> +
> + .pwm_9bit_mask = BIT(4),
> +
> + .num_channels = 6,
> + .channels = (struct lpg_channel_data[]) {
> + { .base = 0xb100 },
> + { .base = 0xb200 },
> + { .base = 0xb300, .triled_mask = BIT(5) },
> + { .base = 0xb400, .triled_mask = BIT(6) },
> + { .base = 0xb500, .triled_mask = BIT(7) },
> + { .base = 0xb600 },
> + },
> +};
> +
> +static const struct lpg_data pm8150b_lpg_data = {
> + .lut_base = 0xb000,
> + .lut_size = 49,
> +
> + .triled_base = 0xd000,
For the LED peripheral under PM8150B we've some quirks. If one of the channels is enabled, then we need to do an additional SDAM register write to trigger a PBS (programmable boot sequence).
This is required to set the headroom voltage of BOB peripheral that is on PM8150L PMIC. When both the LED channels are disabled, a similar register write has to be made
again to trigger the PBS again to unvote the headroom voltage request made before.
> +
> + .pwm_9bit_mask = BIT(4),
> +
> + .num_channels = 2,
> + .channels = (struct lpg_channel_data[]) {
> + { .base = 0xb100, .triled_mask = BIT(7) },
> + { .base = 0xb200, .triled_mask = BIT(6) },
> + },
> +};
> +
> +static const struct lpg_data pm8150l_lpg_data = {
> + .lut_base = 0xb000,
> + .lut_size = 49,
> +
> + .triled_base = 0xd000,
> +
> + .pwm_9bit_mask = BIT(4),
> +
> + .num_channels = 5,
Not a big concern but I'm wondering how to represent 2 different blocks of HW from a PMIC here. First one is a LPG peripheral with 3 channels starting from 0xb100 which is consumed for TRI_LED.
Second one is a PWM peripheral with 2 channel starting from 0xbc00 which can never use LUT specified above. Looks like here you want to represent them as a whole. But in the case, if
an user wants to use the PWM channel (not a LPG channel) along with LUT, it shouldn't be supported. Can this be enforced by allowing LUT to be configured only for a peripheral of subtype LPG?
> + .channels = (struct lpg_channel_data[]) {
> + { .base = 0xb100, .triled_mask = BIT(7) },
> + { .base = 0xb200, .triled_mask = BIT(6) },
> + { .base = 0xb300, .triled_mask = BIT(5) },
> + { .base = 0xbc00 },
> + { .base = 0xbd00 },
> +
> + },
> +};
> +
> +static const struct of_device_id lpg_of_table[] = {
> + { .compatible = "qcom,pm8150b-lpg", .data = &pm8150b_lpg_data },
> + { .compatible = "qcom,pm8150l-lpg", .data = &pm8150l_lpg_data },
> + { .compatible = "qcom,pm8916-pwm", .data = &pm8916_pwm_data },
> + { .compatible = "qcom,pm8941-lpg", .data = &pm8941_lpg_data },
> + { .compatible = "qcom,pm8994-lpg", .data = &pm8994_lpg_data },
> + { .compatible = "qcom,pmi8994-lpg", .data = &pmi8994_lpg_data },
> + { .compatible = "qcom,pmi8998-lpg", .data = &pmi8998_lpg_data },
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, lpg_of_table);
> +
> +static struct platform_driver lpg_driver = {
> + .probe = lpg_probe,
> + .remove = lpg_remove,
> + .driver = {
> + .name = "qcom-spmi-lpg",
> + .of_match_table = lpg_of_table,
> + },
> +};
> +module_platform_driver(lpg_driver);
> +
> +MODULE_DESCRIPTION("Qualcomm LPG LED driver");
> +MODULE_LICENSE("GPL v2");
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