misc: rtsx: make various functions static

[mirror_ubuntu-bionic-kernel.git] / drivers / leds / leds-qcom-lpg.c

/*
 * Copyright (c) 2017 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/leds.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
 * @pwm_9bit_mask: bitmask for enabling 9bit pwm
 * @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
 * @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;

        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
 * @num_channels:       number of @channels
 * @channels:           list of channels associated with the LED
 */
struct lpg_led {
        struct lpg *lpg;

        struct led_classdev cdev;

        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, const u16 *values, 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] = values[i] & 0xff;
                val[1] = values[i] >> 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 u16 *lpg_lut_read(struct lpg *lpg, unsigned int lo_idx,
                         unsigned int hi_idx, size_t *len)
{
        u16 *values;
        u8 val[2];
        int ret;
        int i;

        *len = hi_idx - lo_idx + 1;

        values = kcalloc(*len, sizeof(u16), GFP_KERNEL);
        if (!values)
                return ERR_PTR(-ENOMEM);

        for (i = 0; i < *len; i++) {
                ret = regmap_bulk_read(lpg->map,
                                       lpg->lut_base + LPG_LUT_REG(lo_idx + i),
                                       &val, 2);
                if (ret < 0) {
                        kfree(values);
                        return ERR_PTR(ret);
                }

                values[i] = val[0] | val[1] << 8;
        }

        return values;
}

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_update_bits(lpg->map, lpg->lut_base + RAMP_CONTROL_REG,
                                  mask, 0xff);
}

#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 led_classdev *cdev,
                              enum led_brightness value)
{
        struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
        struct lpg_channel *chan;
        struct lpg *lpg = led->lpg;
        unsigned int duty_us;
        unsigned int triled_mask = 0;
        unsigned int lut_mask = 0;
        int i;

        for (i = 0; i < led->num_channels; i++) {
                chan = led->channels[i];

                if (value == 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 = value * 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 enum led_brightness lpg_brightness_get(struct led_classdev *cdev)
{
        struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
        struct lpg_channel *chan = led->channels[0];
        unsigned long max = (1 << chan->pwm_size) - 1;

        if (!chan->enabled)
                return LED_OFF;
        else if (chan->pattern_lo_idx != chan->pattern_hi_idx)
                return LED_FULL;
        else
                return chan->pwm_value * cdev->max_brightness / max;
}

static int lpg_blink_set(struct led_classdev *cdev,
                         unsigned long *delay_on, unsigned long *delay_off)
{
        struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
        struct lpg_channel *chan = led->channels[0];
        unsigned int period_us;
        unsigned int duty_us;

        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;

        lpg_calc_freq(chan, period_us);
        lpg_calc_duty(chan, duty_us);

        chan->enabled = true;
        chan->ramp_enabled = false;

        lpg_apply(chan);

        return 0;
}

#define interpolate(x1, y1, x2, y2, x) \
        ((y1) + ((y2) - (y1)) * ((x) - (x1)) / ((x2) - (x1)))

static int lpg_pattern_set(struct led_classdev *led_cdev,
                           struct led_pattern *led_pattern, int len,
                           bool repeat)
{
        struct lpg_led *led = container_of(led_cdev, struct lpg_led, cdev);
        struct lpg_channel *chan = led->channels[0];
        struct lpg *lpg = led->lpg;
        unsigned int duration = 0;
        unsigned int min_delta = (unsigned int)-1;
        unsigned int hi_pause;
        unsigned int lo_pause = 0;
        unsigned int lo_idx;
        unsigned int hi_idx;
        unsigned int max = (1 << chan->pwm_size) - 1;
        bool ping_pong = true;
        int brightness_a;
        int brightness_b;
        u16 *pattern;
        int src_idx;
        int dst_idx;
        int step_t;
        int time_a;
        int time_b;
        int value;
        int steps;
        int ret = 0;
        int i;

        /*
         * The led_pattern specifies brightness values, potentially distributed
         * unevenly over the duration of the pattern. The LPG only support
         * evenly distributed values, so we interpolate new values from the
         * led_pattern.
         */

        /* Sum the duration over the inner delta_ts and the tail is hi_pause */
        for (src_idx = 0; src_idx < len - 1; src_idx++)
                duration += led_pattern[src_idx].delta_t;
        hi_pause = led_pattern[src_idx].delta_t;

        for (src_idx = 0; src_idx < len; src_idx++) {
                min_delta = min_t(unsigned int, min_delta,
                                  led_pattern[src_idx].delta_t);
        }

        steps = duration / min_delta + 1;
        pattern = kcalloc(steps, sizeof(*pattern), GFP_KERNEL);
        if (!pattern)
                return -ENOMEM;

        time_a = 0;
        for (src_idx = 0, dst_idx = 0; dst_idx < steps; dst_idx++) {
                /* The timestamp of this evenly distributed data point */
                step_t = dst_idx * min_delta;

                /*
                 * Find time_a - time_b interval from source pattern that spans
                 * step_t
                 */
                while (time_a + led_pattern[src_idx].delta_t < step_t) {
                        if (src_idx >= len - 1)
                                break;
                        time_a += led_pattern[++src_idx].delta_t;
                }

                if (src_idx < len - 1) {
                        time_b = time_a + led_pattern[src_idx].delta_t;

                        brightness_a = led_pattern[src_idx].brightness;
                        brightness_b = led_pattern[src_idx + 1].brightness;

                        /* Interpolate over the source pattern segment */
                        value = interpolate(time_a, brightness_a, time_b,
                                            brightness_b, step_t);
                } else {
                        value = led_pattern[src_idx].brightness;
                }

                /* Scale calculated value to the hardware brightness value */
                pattern[dst_idx] = value * max / led_cdev->max_brightness;
        }

        /* Detect palindromes and use "ping pong" to reduce LUT usage */
        for (dst_idx = 0; dst_idx < steps / 2; dst_idx++) {
                if (pattern[dst_idx] != pattern[len - dst_idx - 1]) {
                        ping_pong = false;
                        break;
                }
        }
        if (ping_pong) {
                steps = (steps + 1) / 2;

                /*
                 * When ping_pong is set the hi_pause will happen in the middle
                 * of the pattern, so we need to use lo_pause to delay between
                 * the loops.
                 */
                if (repeat)
                        lo_pause = hi_pause;

                hi_pause = 0;
        }

        ret = lpg_lut_store(lpg, pattern, steps, &lo_idx, &hi_idx);
        if (ret < 0)
                goto out;

        chan = led->channels[0];

        lpg_lut_free(lpg, chan->pattern_lo_idx, chan->pattern_hi_idx);

        /* Update settings on each associated channel */
        for (i = 0; i < led->num_channels; i++) {
                chan = led->channels[i];

                chan->ramp_duration_ms = duration;
                chan->ramp_ping_pong = ping_pong;
                chan->ramp_oneshot = !repeat;

                chan->pattern_lo_idx = lo_idx;
                chan->pattern_hi_idx = hi_idx;
        }

out:
        kfree(pattern);

        return ret;
}

static int lpg_pattern_clear(struct led_classdev *cdev)
{
        struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
        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 struct led_pattern *lpg_pattern_get(struct led_classdev *cdev,
                                           size_t *len, bool *repeat)
{
        struct led_pattern *led_pattern;
        struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
        struct lpg *lpg = led->lpg;
        struct lpg_channel *chan = led->channels[0];
        unsigned int delta_t;
        unsigned int max = (1 << chan->pwm_size) - 1;
        size_t all_steps;
        size_t steps;
        u16 *pattern;
        size_t i;
        u16 val;

        pattern = lpg_lut_read(lpg, chan->pattern_lo_idx, chan->pattern_hi_idx,
                               &steps);
        if (IS_ERR_OR_NULL(pattern))
                return ERR_CAST(pattern);

        all_steps = chan->ramp_ping_pong ? steps * 2 - 1 : steps;

        delta_t = (chan->ramp_duration_ms + chan->ramp_hi_pause_ms) / all_steps;

        led_pattern = kcalloc(all_steps, sizeof(*pattern), GFP_KERNEL);
        if (!led_pattern) {
                led_pattern = ERR_PTR(-ENOMEM);
                goto out;
        }

        for (i = 0; i < all_steps; i++) {
                if (i < steps)
                        val = pattern[i];
                else
                        val = pattern[steps - i];

                led_pattern[i].delta_t = delta_t;
                led_pattern[i].brightness = val * cdev->max_brightness / max;
        }

        *len = all_steps;
        *repeat = !chan->ramp_oneshot;

out:
        kfree(pattern);
        return led_pattern;
}

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,
                         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);

        state->polarity = PWM_POLARITY_NORMAL;
        state->period = chan->period_us * NSEC_PER_USEC;

        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_add_led(struct lpg *lpg, struct device_node *np)
{
        struct lpg_led *led;
        const char *state;
        int sources;
        int size;
        u32 chan;
        int ret;
        int i;

        sources = of_property_count_u32_elems(np, "led-sources");
        if (sources <= 0) {
                dev_err(lpg->dev, "invalid led-sources of %s\n",
                        np->name);
                return -EINVAL;
        }

        size = sizeof(*led) + sources * sizeof(struct lpg_channel*);
        led = devm_kzalloc(lpg->dev, size, GFP_KERNEL);
        if (!led)
                return -ENOMEM;

        led->lpg = lpg;
        led->num_channels = sources;

        for (i = 0; i < sources; i++) {
                ret = of_property_read_u32_index(np, "led-sources",
                                                 i, &chan);
                if (ret || !chan || chan > lpg->num_channels) {
                        dev_err(lpg->dev,
                                "invalid led-sources of %s\n",
                                np->name);
                        return -EINVAL;
                }

                led->channels[i] = &lpg->channels[chan - 1];

                led->channels[i]->in_use = true;
        }

        /* Use label else node name */
        led->cdev.name = of_get_property(np, "label", NULL) ? : np->name;
        led->cdev.default_trigger = of_get_property(np, "linux,default-trigger", NULL);
        led->cdev.brightness_set = lpg_brightness_set;
        led->cdev.brightness_get = lpg_brightness_get;
        led->cdev.blink_set = lpg_blink_set;
        led->cdev.max_brightness = 255;

        /* Register pattern accessors only if we have a LUT block */
        if (lpg->lut_base) {
                led->cdev.pattern_set = lpg_pattern_set;
                led->cdev.pattern_clear = lpg_pattern_clear;
                led->cdev.pattern_get = lpg_pattern_get;
        }

        if (!of_property_read_string(np, "default-state", &state) &&
            !strcmp(state, "on"))
                led->cdev.brightness = LED_FULL;
        else
                led->cdev.brightness = LED_OFF;

        lpg_brightness_set(&led->cdev, led->cdev.brightness);

        ret = devm_led_classdev_register(lpg->dev, &led->cdev);
        if (ret)
                dev_err(lpg->dev, "unable to register %s\n", led->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);

        return lpg->lut_bitmap ? 0 : -ENOMEM;
}

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 || count != lpg->data->num_channels * 2) {
                ret = count;
                goto err_malformed;
        }

        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 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;

        ret = lpg_parse_dtest(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 TRI LED driver");
MODULE_LICENSE("GPL v2");