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/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 20000ul 52 #define EL_PATTERN_DELAY_MSEC 800u 53 #define EL_PATTERN_LEN 10u 54 #define EL_PATTERN_HALF_LEN (EL_PATTERN_LEN / 2) 55 56 enum 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 71 struct el15203000_led { 72 struct led_classdev ldev; 73 struct el15203000 *priv; 74 u32 reg; 75 }; 76 77 struct 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[]; 84 }; 85 86 #define to_el15203000_led(d) container_of(d, struct el15203000_led, ldev) 87 88 static 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 } 130 131 static 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 } 138 139 static 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 } 155 156 static 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 } 179 180 static 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 } 189 190 static 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 } 229 230 static 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 } 236 237 static 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; 284 285 err_child_out: 286 fwnode_handle_put(child); 287 return ret; 288 } 289 290 static 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 } 317 318 static void el15203000_remove(struct spi_device *spi) 319 { 320 struct el15203000 *priv = spi_get_drvdata(spi); 321 322 mutex_destroy(&priv->lock); 323 } 324 325 static const struct of_device_id el15203000_dt_ids[] = { 326 { .compatible = "crane,el15203000", }, 327 {}, 328 }; 329 330 MODULE_DEVICE_TABLE(of, el15203000_dt_ids); 331 332 static 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 }; 340 341 module_spi_driver(el15203000_driver); 342 343 MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>"); 344 MODULE_DESCRIPTION("el15203000 LED driver"); 345 MODULE_LICENSE("GPL v2"); 346 MODULE_ALIAS("spi:el15203000"); 347