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Subject[PATCH v4 2/4] leds: Add driver for Qualcomm LPG
Date
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@linaro.org>
---

Changes since v3:
- Adopt multicolor model
- Simplified hw_pattern implementation

drivers/leds/Kconfig | 9 +
drivers/leds/Makefile | 1 +
drivers/leds/leds-qcom-lpg.c | 1213 ++++++++++++++++++++++++++++++++++
3 files changed, 1223 insertions(+)
create mode 100644 drivers/leds/leds-qcom-lpg.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 849d3c5f908e..d500648c586f 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -803,6 +803,15 @@ config LEDS_POWERNV
To compile this driver as a module, choose 'm' here: the module
will be called leds-powernv.

+config LEDS_QCOM_LPG
+ tristate "LED support for Qualcomm LPG"
+ depends on LEDS_CLASS_MULTICOLOR
+ depends on OF
+ depends on SPMI
+ help
+ This option enables support for the Light Pulse Generator found in a
+ wide variety of Qualcomm PMICs.
+
config LEDS_SYSCON
bool "LED support for LEDs on system controllers"
depends on LEDS_CLASS=y
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 73e603e1727e..52d0ea26fc35 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -79,6 +79,7 @@ obj-$(CONFIG_LEDS_PCA963X) += leds-pca963x.o
obj-$(CONFIG_LEDS_PM8058) += leds-pm8058.o
obj-$(CONFIG_LEDS_POWERNV) += leds-powernv.o
obj-$(CONFIG_LEDS_PWM) += leds-pwm.o
+obj-$(CONFIG_LEDS_QCOM_LPG) += leds-qcom-lpg.o
obj-$(CONFIG_LEDS_REGULATOR) += leds-regulator.o
obj-$(CONFIG_LEDS_S3C24XX) += leds-s3c24xx.o
obj-$(CONFIG_LEDS_SC27XX_BLTC) += leds-sc27xx-bltc.o
diff --git a/drivers/leds/leds-qcom-lpg.c b/drivers/leds/leds-qcom-lpg.c
new file mode 100644
index 000000000000..17594ce37c9a
--- /dev/null
+++ b/drivers/leds/leds-qcom-lpg.c
@@ -0,0 +1,1213 @@
+/*
+ * Copyright (c) 2017-2019 Linaro Ltd
+ * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+#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
+ * @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;
+
+ 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, overriden 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_duration_ms: length (in milliseconds) of one pattern run
+ * @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_duration_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
+ * @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;
+ unsigned int pwm_9bit_mask;
+ int num_channels;
+ struct lpg_channel_data *channels;
+};
+
+static int triled_set(struct lpg *lpg, unsigned int mask, bool 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 ? mask : 0);
+}
+
+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;
+ u8 val[2];
+ 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[0] = pattern[i].brightness & 0xff;
+ val[1] = pattern[i].brightness >> 8;
+
+ regmap_bulk_write(lpg->map,
+ lpg->lut_base + LPG_LUT_REG(idx + i), val, 2);
+ }
+
+ 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 < ((unsigned int)(-1) / NSEC_PER_USEC)) {
+ period_n = (period_us * NSEC_PER_USEC) >> 6;
+ n = 6;
+ } else {
+ period_n = (period_us >> 9) * NSEC_PER_USEC;
+ n = 9;
+ }
+
+ min_err = last_err = (unsigned int)(-1);
+ 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++) {
+ if (period_n > tmp_p)
+ cur_err = period_n - tmp_p;
+ else
+ cur_err = tmp_p - period_n;
+
+ 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 long max = (1 << chan->pwm_size) - 1;
+ unsigned long val;
+
+ /* Figure out pwm_value with overflow handling */
+ if (duty_us < 1 << (sizeof(val) * 8 - chan->pwm_size))
+ val = (duty_us << chan->pwm_size) / chan->period_us;
+ else
+ val = duty_us / (chan->period_us >> chan->pwm_size);
+
+ if (val > max)
+ val = max;
+
+ chan->pwm_value = val;
+}
+
+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)
+{
+ u8 val[] = { chan->pwm_value & 0xff, chan->pwm_value >> 8 };
+ struct lpg *lpg = chan->lpg;
+
+ if (!chan->enabled)
+ return;
+
+ regmap_bulk_write(lpg->map, chan->base + PWM_VALUE_REG, val, 2);
+}
+
+#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 = DIV_ROUND_UP(chan->ramp_duration_ms, pattern_len);
+ 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 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_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_mask |= 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_mask |= chan->triled_mask;
+ }
+
+ lpg_apply(chan);
+ }
+
+ /* Toggle triled lines */
+ if (triled_mask)
+ triled_set(lpg, triled_mask, chan->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);
+}
+
+#define interpolate(x1, y1, x2, y2, x) \
+ ((y1) + ((y2) - (y1)) * ((x) - (x1)) / ((x2) - (x1)))
+
+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)
+ goto out;
+
+ for (i = 0; i < led->num_channels; i++) {
+ chan = led->channels[i];
+
+ chan->ramp_duration_ms = pattern[0].delta_t * len;
+ 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;
+ }
+
+out:
+ return ret;
+}
+
+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, state->period / NSEC_PER_USEC);
+ lpg_calc_duty(chan, state->duty_cycle / NSEC_PER_USEC);
+ chan->enabled = state->enabled;
+
+ lpg_apply(chan);
+
+ triled_set(lpg, chan->triled_mask, chan->enabled);
+
+ 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 dtest[2];
+ u32 color = LED_COLOR_ID_GREEN;
+ u32 reg;
+ int ret;
+
+ ret = of_property_read_u32(np, "reg", &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)
+ return ret;
+
+ chan->color = color;
+
+ ret = of_property_read_u32_array(np, "qcom,dtest", dtest, 2);
+ if (ret < 0 && ret != -EINVAL) {
+ dev_err(lpg->dev, "malformed qcom,dtest of %pOFn\n", np);
+ return ret;
+ } else if (!ret) {
+ chan->dtest_line = dtest[0];
+ chan->dtest_value = dtest[1];
+ }
+
+ *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 size;
+ int ret;
+ int i;
+
+ ret = of_property_read_u32(np, "color", &color);
+ if (ret < 0 && ret != -EINVAL)
+ return ret;
+
+ if (color == LED_COLOR_ID_MULTI)
+ num_channels = of_get_available_child_count(np);
+ else
+ num_channels = 1;
+
+ size = sizeof(*led) + num_channels * sizeof(struct lpg_channel*);
+ led = devm_kzalloc(lpg->dev, size, 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;
+
+ 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 */
+ regmap_write(lpg->map, lpg->triled_base + TRI_LED_ATC_CTL, 0);
+
+ /* Configure power source */
+ 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_LONGS(lpg->lut_size) * sizeof(unsigned long);
+ lpg->lut_bitmap = devm_kzalloc(lpg->dev, bitmap_size, GFP_KERNEL);
+
+ bitmap_clear(lpg->lut_bitmap, 0, lpg->lut_size);
+ return lpg->lut_bitmap ? 0 : -ENOMEM;
+}
+
+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_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,
+
+ .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,
+
+ .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,
+
+ .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 of_device_id lpg_of_table[] = {
+ { .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");
--
2.28.0
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  Last update: 2020-09-29 05:15    [W:0.101 / U:10.444 seconds]
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