1 // SPDX-License-Identifier: GPL-2.0 2 // 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/module.h> 8 #include <linux/of_device.h> 9 #include <linux/spi/spi.h> 10 11 /* 12 * EL15203000 SPI protocol description: 13 * +-----+---------+ 14 * | LED | COMMAND | 15 * +-----+---------+ 16 * | 1 | 1 | 17 * +-----+---------+ 18 * (*) LEDs MCU board expects 20 msec delay per byte. 19 * 20 * LEDs: 21 * +----------+--------------+-------------------------------------------+ 22 * | ID | NAME | DESCRIPTION | 23 * +----------+--------------+-------------------------------------------+ 24 * | 'P' 0x50 | Pipe | Consists from 5 LEDs, controlled by board | 25 * +----------+--------------+-------------------------------------------+ 26 * | 'S' 0x53 | Screen frame | Light tube around the screen | 27 * +----------+--------------+-------------------------------------------+ 28 * | 'V' 0x56 | Vending area | Highlights a cup of coffee | 29 * +----------+--------------+-------------------------------------------+ 30 * 31 * COMMAND: 32 * +----------+-----------------+--------------+--------------+ 33 * | VALUES | PIPE | SCREEN FRAME | VENDING AREA | 34 * +----------+-----------------+--------------+--------------+ 35 * | '0' 0x30 | Off | 36 * +----------+-----------------------------------------------+ 37 * | '1' 0x31 | On | 38 * +----------+-----------------+--------------+--------------+ 39 * | '2' 0x32 | Cascade | Breathing | 40 * +----------+-----------------+--------------+ 41 * | '3' 0x33 | Inverse cascade | 42 * +----------+-----------------+ 43 * | '4' 0x34 | Bounce | 44 * +----------+-----------------+ 45 * | '5' 0x35 | Inverse bounce | 46 * +----------+-----------------+ 47 */ 48 49 /* EL15203000 default settings */ 50 #define EL_FW_DELAY_USEC 20000ul 51 #define EL_PATTERN_DELAY_MSEC 800u 52 #define EL_PATTERN_LEN 10u 53 #define EL_PATTERN_HALF_LEN (EL_PATTERN_LEN / 2) 54 55 enum el15203000_command { 56 /* for all LEDs */ 57 EL_OFF = '0', 58 EL_ON = '1', 59 60 /* for Screen LED */ 61 EL_SCREEN_BREATHING = '2', 62 63 /* for Pipe LED */ 64 EL_PIPE_CASCADE = '2', 65 EL_PIPE_INV_CASCADE = '3', 66 EL_PIPE_BOUNCE = '4', 67 EL_PIPE_INV_BOUNCE = '5', 68 }; 69 70 struct el15203000_led { 71 struct el15203000 *priv; 72 struct led_classdev ldev; 73 u32 reg; 74 }; 75 76 struct el15203000 { 77 struct device *dev; 78 struct mutex lock; 79 struct spi_device *spi; 80 unsigned long delay; 81 size_t count; 82 struct el15203000_led leds[]; 83 }; 84 85 static int el15203000_cmd(struct el15203000_led *led, u8 brightness) 86 { 87 int ret; 88 u8 cmd[2]; 89 size_t i; 90 91 mutex_lock(&led->priv->lock); 92 93 dev_dbg(led->priv->dev, "Set brightness of 0x%02x(%c) to 0x%02x(%c)", 94 led->reg, led->reg, brightness, brightness); 95 96 /* to avoid SPI mistiming with firmware we should wait some time */ 97 if (time_after(led->priv->delay, jiffies)) { 98 dev_dbg(led->priv->dev, "Wait %luus to sync", 99 EL_FW_DELAY_USEC); 100 101 usleep_range(EL_FW_DELAY_USEC, 102 EL_FW_DELAY_USEC + 1); 103 } 104 105 cmd[0] = led->reg; 106 cmd[1] = brightness; 107 108 for (i = 0; i < ARRAY_SIZE(cmd); i++) { 109 if (i) 110 usleep_range(EL_FW_DELAY_USEC, 111 EL_FW_DELAY_USEC + 1); 112 113 ret = spi_write(led->priv->spi, &cmd[i], sizeof(cmd[i])); 114 if (ret) { 115 dev_err(led->priv->dev, 116 "spi_write() error %d", ret); 117 break; 118 } 119 } 120 121 led->priv->delay = jiffies + usecs_to_jiffies(EL_FW_DELAY_USEC); 122 123 mutex_unlock(&led->priv->lock); 124 125 return ret; 126 } 127 128 static int el15203000_set_blocking(struct led_classdev *ldev, 129 enum led_brightness brightness) 130 { 131 struct el15203000_led *led = container_of(ldev, 132 struct el15203000_led, 133 ldev); 134 135 return el15203000_cmd(led, brightness == LED_OFF ? EL_OFF : EL_ON); 136 } 137 138 static int el15203000_pattern_set_S(struct led_classdev *ldev, 139 struct led_pattern *pattern, 140 u32 len, int repeat) 141 { 142 struct el15203000_led *led = container_of(ldev, 143 struct el15203000_led, 144 ldev); 145 146 if (repeat > 0 || len != 2 || 147 pattern[0].delta_t != 4000 || pattern[0].brightness != 0 || 148 pattern[1].delta_t != 4000 || pattern[1].brightness != 1) 149 return -EINVAL; 150 151 dev_dbg(led->priv->dev, "Breathing mode for 0x%02x(%c)", 152 led->reg, led->reg); 153 154 return el15203000_cmd(led, EL_SCREEN_BREATHING); 155 } 156 157 static bool is_cascade(const struct led_pattern *pattern, u32 len, 158 bool inv, bool right) 159 { 160 int val, t; 161 u32 i; 162 163 if (len != EL_PATTERN_HALF_LEN) 164 return false; 165 166 val = right ? BIT(4) : BIT(0); 167 168 for (i = 0; i < len; i++) { 169 t = inv ? ~val & GENMASK(4, 0) : val; 170 171 if (pattern[i].delta_t != EL_PATTERN_DELAY_MSEC || 172 pattern[i].brightness != t) 173 return false; 174 175 val = right ? val >> 1 : val << 1; 176 } 177 178 return true; 179 } 180 181 static bool is_bounce(const struct led_pattern *pattern, u32 len, bool inv) 182 { 183 if (len != EL_PATTERN_LEN) 184 return false; 185 186 return is_cascade(pattern, EL_PATTERN_HALF_LEN, inv, false) && 187 is_cascade(pattern + EL_PATTERN_HALF_LEN, 188 EL_PATTERN_HALF_LEN, inv, true); 189 } 190 191 static int el15203000_pattern_set_P(struct led_classdev *ldev, 192 struct led_pattern *pattern, 193 u32 len, int repeat) 194 { 195 u8 cmd; 196 struct el15203000_led *led = container_of(ldev, 197 struct el15203000_led, 198 ldev); 199 200 if (repeat > 0) 201 return -EINVAL; 202 203 if (is_cascade(pattern, len, false, false)) { 204 dev_dbg(led->priv->dev, "Cascade mode for 0x%02x(%c)", 205 led->reg, led->reg); 206 207 cmd = EL_PIPE_CASCADE; 208 } else if (is_cascade(pattern, len, true, false)) { 209 dev_dbg(led->priv->dev, "Inverse cascade mode for 0x%02x(%c)", 210 led->reg, led->reg); 211 212 cmd = EL_PIPE_INV_CASCADE; 213 } else if (is_bounce(pattern, len, false)) { 214 dev_dbg(led->priv->dev, "Bounce mode for 0x%02x(%c)", 215 led->reg, led->reg); 216 217 cmd = EL_PIPE_BOUNCE; 218 } else if (is_bounce(pattern, len, true)) { 219 dev_dbg(led->priv->dev, "Inverse bounce mode for 0x%02x(%c)", 220 led->reg, led->reg); 221 222 cmd = EL_PIPE_INV_BOUNCE; 223 } else { 224 dev_err(led->priv->dev, "Invalid hw_pattern for 0x%02x(%c)!", 225 led->reg, led->reg); 226 227 return -EINVAL; 228 } 229 230 return el15203000_cmd(led, cmd); 231 } 232 233 static int el15203000_pattern_clear(struct led_classdev *ldev) 234 { 235 struct el15203000_led *led = container_of(ldev, 236 struct el15203000_led, 237 ldev); 238 239 return el15203000_cmd(led, EL_OFF); 240 } 241 242 static int el15203000_probe_dt(struct el15203000 *priv) 243 { 244 struct el15203000_led *led = priv->leds; 245 struct fwnode_handle *child; 246 int ret; 247 248 device_for_each_child_node(priv->dev, child) { 249 struct led_init_data init_data = {}; 250 251 ret = fwnode_property_read_u32(child, "reg", &led->reg); 252 if (ret) { 253 dev_err(priv->dev, "LED without ID number"); 254 fwnode_handle_put(child); 255 256 break; 257 } 258 259 if (led->reg > U8_MAX) { 260 dev_err(priv->dev, "LED value %d is invalid", led->reg); 261 fwnode_handle_put(child); 262 263 return -EINVAL; 264 } 265 266 fwnode_property_read_string(child, "linux,default-trigger", 267 &led->ldev.default_trigger); 268 269 led->priv = priv; 270 led->ldev.max_brightness = LED_ON; 271 led->ldev.brightness_set_blocking = el15203000_set_blocking; 272 273 if (led->reg == 'S') { 274 led->ldev.pattern_set = el15203000_pattern_set_S; 275 led->ldev.pattern_clear = el15203000_pattern_clear; 276 } else if (led->reg == 'P') { 277 led->ldev.pattern_set = el15203000_pattern_set_P; 278 led->ldev.pattern_clear = el15203000_pattern_clear; 279 } 280 281 init_data.fwnode = child; 282 ret = devm_led_classdev_register_ext(priv->dev, &led->ldev, 283 &init_data); 284 if (ret) { 285 dev_err(priv->dev, 286 "failed to register LED device %s, err %d", 287 led->ldev.name, ret); 288 fwnode_handle_put(child); 289 290 break; 291 } 292 293 led++; 294 } 295 296 return ret; 297 } 298 299 static int el15203000_probe(struct spi_device *spi) 300 { 301 struct el15203000 *priv; 302 size_t count; 303 304 count = device_get_child_node_count(&spi->dev); 305 if (!count) { 306 dev_err(&spi->dev, "LEDs are not defined in device tree!"); 307 return -ENODEV; 308 } 309 310 priv = devm_kzalloc(&spi->dev, struct_size(priv, leds, count), 311 GFP_KERNEL); 312 if (!priv) 313 return -ENOMEM; 314 315 mutex_init(&priv->lock); 316 priv->count = count; 317 priv->dev = &spi->dev; 318 priv->spi = spi; 319 priv->delay = jiffies - 320 usecs_to_jiffies(EL_FW_DELAY_USEC); 321 322 spi_set_drvdata(spi, priv); 323 324 return el15203000_probe_dt(priv); 325 } 326 327 static int el15203000_remove(struct spi_device *spi) 328 { 329 struct el15203000 *priv = spi_get_drvdata(spi); 330 331 mutex_destroy(&priv->lock); 332 333 return 0; 334 } 335 336 static const struct of_device_id el15203000_dt_ids[] = { 337 { .compatible = "crane,el15203000", }, 338 {}, 339 }; 340 341 MODULE_DEVICE_TABLE(of, el15203000_dt_ids); 342 343 static struct spi_driver el15203000_driver = { 344 .probe = el15203000_probe, 345 .remove = el15203000_remove, 346 .driver = { 347 .name = KBUILD_MODNAME, 348 .of_match_table = el15203000_dt_ids, 349 }, 350 }; 351 352 module_spi_driver(el15203000_driver); 353 354 MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>"); 355 MODULE_DESCRIPTION("el15203000 LED driver"); 356 MODULE_LICENSE("GPL v2"); 357 MODULE_ALIAS("spi:el15203000"); 358