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1// SPDX-License-Identifier: GPL-2.02// Copyright (c) 2019 Crane Merchandising Systems. All rights reserved.3// Copyright (C) 2019 Oleh Kravchenko <oleg@kaa.org.ua>4 5#include <linux/delay.h>6#include <linux/leds.h>7#include <linux/mod_devicetable.h>8#include <linux/module.h>9#include <linux/property.h>10#include <linux/spi/spi.h>11 12/*13 * EL15203000 SPI protocol description:14 * +-----+---------+15 * | LED | COMMAND |16 * +-----+---------+17 * | 1 | 1 |18 * +-----+---------+19 * (*) LEDs MCU board expects 20 msec delay per byte.20 *21 * LEDs:22 * +----------+--------------+-------------------------------------------+23 * | ID | NAME | DESCRIPTION |24 * +----------+--------------+-------------------------------------------+25 * | 'P' 0x50 | Pipe | Consists from 5 LEDs, controlled by board |26 * +----------+--------------+-------------------------------------------+27 * | 'S' 0x53 | Screen frame | Light tube around the screen |28 * +----------+--------------+-------------------------------------------+29 * | 'V' 0x56 | Vending area | Highlights a cup of coffee |30 * +----------+--------------+-------------------------------------------+31 *32 * COMMAND:33 * +----------+-----------------+--------------+--------------+34 * | VALUES | PIPE | SCREEN FRAME | VENDING AREA |35 * +----------+-----------------+--------------+--------------+36 * | '0' 0x30 | Off |37 * +----------+-----------------------------------------------+38 * | '1' 0x31 | On |39 * +----------+-----------------+--------------+--------------+40 * | '2' 0x32 | Cascade | Breathing |41 * +----------+-----------------+--------------+42 * | '3' 0x33 | Inverse cascade |43 * +----------+-----------------+44 * | '4' 0x34 | Bounce |45 * +----------+-----------------+46 * | '5' 0x35 | Inverse bounce |47 * +----------+-----------------+48 */49 50/* EL15203000 default settings */51#define EL_FW_DELAY_USEC 20000ul52#define EL_PATTERN_DELAY_MSEC 800u53#define EL_PATTERN_LEN 10u54#define EL_PATTERN_HALF_LEN (EL_PATTERN_LEN / 2)55 56enum el15203000_command {57 /* for all LEDs */58 EL_OFF = '0',59 EL_ON = '1',60 61 /* for Screen LED */62 EL_SCREEN_BREATHING = '2',63 64 /* for Pipe LED */65 EL_PIPE_CASCADE = '2',66 EL_PIPE_INV_CASCADE = '3',67 EL_PIPE_BOUNCE = '4',68 EL_PIPE_INV_BOUNCE = '5',69};70 71struct el15203000_led {72 struct led_classdev ldev;73 struct el15203000 *priv;74 u32 reg;75};76 77struct el15203000 {78 struct device *dev;79 struct mutex lock;80 struct spi_device *spi;81 unsigned long delay;82 size_t count;83 struct el15203000_led leds[] __counted_by(count);84};85 86#define to_el15203000_led(d) container_of(d, struct el15203000_led, ldev)87 88static int el15203000_cmd(struct el15203000_led *led, u8 brightness)89{90 int ret;91 u8 cmd[2];92 size_t i;93 94 mutex_lock(&led->priv->lock);95 96 dev_dbg(led->priv->dev, "Set brightness of 0x%02x(%c) to 0x%02x(%c)",97 led->reg, led->reg, brightness, brightness);98 99 /* to avoid SPI mistiming with firmware we should wait some time */100 if (time_after(led->priv->delay, jiffies)) {101 dev_dbg(led->priv->dev, "Wait %luus to sync",102 EL_FW_DELAY_USEC);103 104 usleep_range(EL_FW_DELAY_USEC,105 EL_FW_DELAY_USEC + 1);106 }107 108 cmd[0] = led->reg;109 cmd[1] = brightness;110 111 for (i = 0; i < ARRAY_SIZE(cmd); i++) {112 if (i)113 usleep_range(EL_FW_DELAY_USEC,114 EL_FW_DELAY_USEC + 1);115 116 ret = spi_write(led->priv->spi, &cmd[i], sizeof(cmd[i]));117 if (ret) {118 dev_err(led->priv->dev,119 "spi_write() error %d", ret);120 break;121 }122 }123 124 led->priv->delay = jiffies + usecs_to_jiffies(EL_FW_DELAY_USEC);125 126 mutex_unlock(&led->priv->lock);127 128 return ret;129}130 131static int el15203000_set_blocking(struct led_classdev *ldev,132 enum led_brightness brightness)133{134 struct el15203000_led *led = to_el15203000_led(ldev);135 136 return el15203000_cmd(led, brightness == LED_OFF ? EL_OFF : EL_ON);137}138 139static int el15203000_pattern_set_S(struct led_classdev *ldev,140 struct led_pattern *pattern,141 u32 len, int repeat)142{143 struct el15203000_led *led = to_el15203000_led(ldev);144 145 if (repeat > 0 || len != 2 ||146 pattern[0].delta_t != 4000 || pattern[0].brightness != 0 ||147 pattern[1].delta_t != 4000 || pattern[1].brightness != 1)148 return -EINVAL;149 150 dev_dbg(led->priv->dev, "Breathing mode for 0x%02x(%c)",151 led->reg, led->reg);152 153 return el15203000_cmd(led, EL_SCREEN_BREATHING);154}155 156static bool is_cascade(const struct led_pattern *pattern, u32 len,157 bool inv, bool right)158{159 int val, t;160 u32 i;161 162 if (len != EL_PATTERN_HALF_LEN)163 return false;164 165 val = right ? BIT(4) : BIT(0);166 167 for (i = 0; i < len; i++) {168 t = inv ? ~val & GENMASK(4, 0) : val;169 170 if (pattern[i].delta_t != EL_PATTERN_DELAY_MSEC ||171 pattern[i].brightness != t)172 return false;173 174 val = right ? val >> 1 : val << 1;175 }176 177 return true;178}179 180static bool is_bounce(const struct led_pattern *pattern, u32 len, bool inv)181{182 if (len != EL_PATTERN_LEN)183 return false;184 185 return is_cascade(pattern, EL_PATTERN_HALF_LEN, inv, false) &&186 is_cascade(pattern + EL_PATTERN_HALF_LEN,187 EL_PATTERN_HALF_LEN, inv, true);188}189 190static int el15203000_pattern_set_P(struct led_classdev *ldev,191 struct led_pattern *pattern,192 u32 len, int repeat)193{194 struct el15203000_led *led = to_el15203000_led(ldev);195 u8 cmd;196 197 if (repeat > 0)198 return -EINVAL;199 200 if (is_cascade(pattern, len, false, false)) {201 dev_dbg(led->priv->dev, "Cascade mode for 0x%02x(%c)",202 led->reg, led->reg);203 204 cmd = EL_PIPE_CASCADE;205 } else if (is_cascade(pattern, len, true, false)) {206 dev_dbg(led->priv->dev, "Inverse cascade mode for 0x%02x(%c)",207 led->reg, led->reg);208 209 cmd = EL_PIPE_INV_CASCADE;210 } else if (is_bounce(pattern, len, false)) {211 dev_dbg(led->priv->dev, "Bounce mode for 0x%02x(%c)",212 led->reg, led->reg);213 214 cmd = EL_PIPE_BOUNCE;215 } else if (is_bounce(pattern, len, true)) {216 dev_dbg(led->priv->dev, "Inverse bounce mode for 0x%02x(%c)",217 led->reg, led->reg);218 219 cmd = EL_PIPE_INV_BOUNCE;220 } else {221 dev_err(led->priv->dev, "Invalid hw_pattern for 0x%02x(%c)!",222 led->reg, led->reg);223 224 return -EINVAL;225 }226 227 return el15203000_cmd(led, cmd);228}229 230static int el15203000_pattern_clear(struct led_classdev *ldev)231{232 struct el15203000_led *led = to_el15203000_led(ldev);233 234 return el15203000_cmd(led, EL_OFF);235}236 237static int el15203000_probe_dt(struct el15203000 *priv)238{239 struct el15203000_led *led = priv->leds;240 struct fwnode_handle *child;241 int ret;242 243 device_for_each_child_node(priv->dev, child) {244 struct led_init_data init_data = {};245 246 ret = fwnode_property_read_u32(child, "reg", &led->reg);247 if (ret) {248 dev_err(priv->dev, "LED without ID number");249 goto err_child_out;250 }251 252 if (led->reg > U8_MAX) {253 dev_err(priv->dev, "LED value %d is invalid", led->reg);254 ret = -EINVAL;255 goto err_child_out;256 }257 258 led->priv = priv;259 led->ldev.max_brightness = LED_ON;260 led->ldev.brightness_set_blocking = el15203000_set_blocking;261 262 if (led->reg == 'S') {263 led->ldev.pattern_set = el15203000_pattern_set_S;264 led->ldev.pattern_clear = el15203000_pattern_clear;265 } else if (led->reg == 'P') {266 led->ldev.pattern_set = el15203000_pattern_set_P;267 led->ldev.pattern_clear = el15203000_pattern_clear;268 }269 270 init_data.fwnode = child;271 ret = devm_led_classdev_register_ext(priv->dev, &led->ldev,272 &init_data);273 if (ret) {274 dev_err(priv->dev,275 "failed to register LED device %s, err %d",276 led->ldev.name, ret);277 goto err_child_out;278 }279 280 led++;281 }282 283 return 0;284 285err_child_out:286 fwnode_handle_put(child);287 return ret;288}289 290static int el15203000_probe(struct spi_device *spi)291{292 struct el15203000 *priv;293 size_t count;294 295 count = device_get_child_node_count(&spi->dev);296 if (!count) {297 dev_err(&spi->dev, "LEDs are not defined in device tree!");298 return -ENODEV;299 }300 301 priv = devm_kzalloc(&spi->dev, struct_size(priv, leds, count),302 GFP_KERNEL);303 if (!priv)304 return -ENOMEM;305 306 mutex_init(&priv->lock);307 priv->count = count;308 priv->dev = &spi->dev;309 priv->spi = spi;310 priv->delay = jiffies -311 usecs_to_jiffies(EL_FW_DELAY_USEC);312 313 spi_set_drvdata(spi, priv);314 315 return el15203000_probe_dt(priv);316}317 318static void el15203000_remove(struct spi_device *spi)319{320 struct el15203000 *priv = spi_get_drvdata(spi);321 322 mutex_destroy(&priv->lock);323}324 325static const struct of_device_id el15203000_dt_ids[] = {326 { .compatible = "crane,el15203000", },327 {},328};329 330MODULE_DEVICE_TABLE(of, el15203000_dt_ids);331 332static struct spi_driver el15203000_driver = {333 .probe = el15203000_probe,334 .remove = el15203000_remove,335 .driver = {336 .name = KBUILD_MODNAME,337 .of_match_table = el15203000_dt_ids,338 },339};340 341module_spi_driver(el15203000_driver);342 343MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>");344MODULE_DESCRIPTION("el15203000 LED driver");345MODULE_LICENSE("GPL v2");346MODULE_ALIAS("spi:el15203000");347