drivers/leds/leds-el15203000.c

   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 led_classdev     ldev;
  72         struct el15203000       *priv;
  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 #define to_el15203000_led(d)    container_of(d, struct el15203000_led, ldev)
  86
  87 static int el15203000_cmd(struct el15203000_led *led, u8 brightness)
  88 {
  89         int             ret;
  90         u8              cmd[2];
  91         size_t          i;
  92
  93         mutex_lock(&led->priv->lock);
  94
  95         dev_dbg(led->priv->dev, "Set brightness of 0x%02x(%c) to 0x%02x(%c)",
  96                 led->reg, led->reg, brightness, brightness);
  97
  98         /* to avoid SPI mistiming with firmware we should wait some time */
  99         if (time_after(led->priv->delay, jiffies)) {
 100                 dev_dbg(led->priv->dev, "Wait %luus to sync",
 101                         EL_FW_DELAY_USEC);
 102
 103                 usleep_range(EL_FW_DELAY_USEC,
 104                              EL_FW_DELAY_USEC + 1);
 105         }
 106
 107         cmd[0] = led->reg;
 108         cmd[1] = brightness;
 109
 110         for (i = 0; i < ARRAY_SIZE(cmd); i++) {
 111                 if (i)
 112                         usleep_range(EL_FW_DELAY_USEC,
 113                                      EL_FW_DELAY_USEC + 1);
 114
 115                 ret = spi_write(led->priv->spi, &cmd[i], sizeof(cmd[i]));
 116                 if (ret) {
 117                         dev_err(led->priv->dev,
 118                                 "spi_write() error %d", ret);
 119                         break;
 120                 }
 121         }
 122
 123         led->priv->delay = jiffies + usecs_to_jiffies(EL_FW_DELAY_USEC);
 124
 125         mutex_unlock(&led->priv->lock);
 126
 127         return ret;
 128 }
 129
 130 static int el15203000_set_blocking(struct led_classdev *ldev,
 131                                    enum led_brightness brightness)
 132 {
 133         struct el15203000_led *led = to_el15203000_led(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 = to_el15203000_led(ldev);
 143
 144         if (repeat > 0 || len != 2 ||
 145             pattern[0].delta_t != 4000 || pattern[0].brightness != 0 ||
 146             pattern[1].delta_t != 4000 || pattern[1].brightness != 1)
 147                 return -EINVAL;
 148
 149         dev_dbg(led->priv->dev, "Breathing mode for 0x%02x(%c)",
 150                 led->reg, led->reg);
 151
 152         return el15203000_cmd(led, EL_SCREEN_BREATHING);
 153 }
 154
 155 static bool is_cascade(const struct led_pattern *pattern, u32 len,
 156                        bool inv, bool right)
 157 {
 158         int val, t;
 159         u32 i;
 160
 161         if (len != EL_PATTERN_HALF_LEN)
 162                 return false;
 163
 164         val = right ? BIT(4) : BIT(0);
 165
 166         for (i = 0; i < len; i++) {
 167                 t = inv ? ~val & GENMASK(4, 0) : val;
 168
 169                 if (pattern[i].delta_t != EL_PATTERN_DELAY_MSEC ||
 170                     pattern[i].brightness != t)
 171                         return false;
 172
 173                 val = right ? val >> 1 : val << 1;
 174         }
 175
 176         return true;
 177 }
 178
 179 static bool is_bounce(const struct led_pattern *pattern, u32 len, bool inv)
 180 {
 181         if (len != EL_PATTERN_LEN)
 182                 return false;
 183
 184         return is_cascade(pattern, EL_PATTERN_HALF_LEN, inv, false) &&
 185                is_cascade(pattern + EL_PATTERN_HALF_LEN,
 186                           EL_PATTERN_HALF_LEN, inv, true);
 187 }
 188
 189 static int el15203000_pattern_set_P(struct led_classdev *ldev,
 190                                     struct led_pattern *pattern,
 191                                     u32 len, int repeat)
 192 {
 193         struct el15203000_led   *led = to_el15203000_led(ldev);
 194         u8                      cmd;
 195
 196         if (repeat > 0)
 197                 return -EINVAL;
 198
 199         if (is_cascade(pattern, len, false, false)) {
 200                 dev_dbg(led->priv->dev, "Cascade mode for 0x%02x(%c)",
 201                         led->reg, led->reg);
 202
 203                 cmd = EL_PIPE_CASCADE;
 204         } else if (is_cascade(pattern, len, true, false)) {
 205                 dev_dbg(led->priv->dev, "Inverse cascade mode for 0x%02x(%c)",
 206                         led->reg, led->reg);
 207
 208                 cmd = EL_PIPE_INV_CASCADE;
 209         } else if (is_bounce(pattern, len, false)) {
 210                 dev_dbg(led->priv->dev, "Bounce mode for 0x%02x(%c)",
 211                         led->reg, led->reg);
 212
 213                 cmd = EL_PIPE_BOUNCE;
 214         } else if (is_bounce(pattern, len, true)) {
 215                 dev_dbg(led->priv->dev, "Inverse bounce mode for 0x%02x(%c)",
 216                         led->reg, led->reg);
 217
 218                 cmd = EL_PIPE_INV_BOUNCE;
 219         } else {
 220                 dev_err(led->priv->dev, "Invalid hw_pattern for 0x%02x(%c)!",
 221                         led->reg, led->reg);
 222
 223                 return -EINVAL;
 224         }
 225
 226         return el15203000_cmd(led, cmd);
 227 }
 228
 229 static int el15203000_pattern_clear(struct led_classdev *ldev)
 230 {
 231         struct el15203000_led *led = to_el15203000_led(ldev);
 232
 233         return el15203000_cmd(led, EL_OFF);
 234 }
 235
 236 static int el15203000_probe_dt(struct el15203000 *priv)
 237 {
 238         struct el15203000_led   *led = priv->leds;
 239         struct fwnode_handle    *child;
 240         int                     ret;
 241
 242         device_for_each_child_node(priv->dev, child) {
 243                 struct led_init_data init_data = {};
 244
 245                 ret = fwnode_property_read_u32(child, "reg", &led->reg);
 246                 if (ret) {
 247                         dev_err(priv->dev, "LED without ID number");
 248                         goto err_child_out;
 249                 }
 250
 251                 if (led->reg > U8_MAX) {
 252                         dev_err(priv->dev, "LED value %d is invalid", led->reg);
 253                         ret = -EINVAL;
 254                         goto err_child_out;
 255                 }
 256
 257                 led->priv                         = priv;
 258                 led->ldev.max_brightness          = LED_ON;
 259                 led->ldev.brightness_set_blocking = el15203000_set_blocking;
 260
 261                 if (led->reg == 'S') {
 262                         led->ldev.pattern_set   = el15203000_pattern_set_S;
 263                         led->ldev.pattern_clear = el15203000_pattern_clear;
 264                 } else if (led->reg == 'P') {
 265                         led->ldev.pattern_set   = el15203000_pattern_set_P;
 266                         led->ldev.pattern_clear = el15203000_pattern_clear;
 267                 }
 268
 269                 init_data.fwnode = child;
 270                 ret = devm_led_classdev_register_ext(priv->dev, &led->ldev,
 271                                                      &init_data);
 272                 if (ret) {
 273                         dev_err(priv->dev,
 274                                 "failed to register LED device %s, err %d",
 275                                 led->ldev.name, ret);
 276                         goto err_child_out;
 277                 }
 278
 279                 led++;
 280         }
 281
 282         return 0;
 283
 284 err_child_out:
 285         fwnode_handle_put(child);
 286         return ret;
 287 }
 288
 289 static int el15203000_probe(struct spi_device *spi)
 290 {
 291         struct el15203000       *priv;
 292         size_t                  count;
 293
 294         count = device_get_child_node_count(&spi->dev);
 295         if (!count) {
 296                 dev_err(&spi->dev, "LEDs are not defined in device tree!");
 297                 return -ENODEV;
 298         }
 299
 300         priv = devm_kzalloc(&spi->dev, struct_size(priv, leds, count),
 301                             GFP_KERNEL);
 302         if (!priv)
 303                 return -ENOMEM;
 304
 305         mutex_init(&priv->lock);
 306         priv->count     = count;
 307         priv->dev       = &spi->dev;
 308         priv->spi       = spi;
 309         priv->delay     = jiffies -
 310                           usecs_to_jiffies(EL_FW_DELAY_USEC);
 311
 312         spi_set_drvdata(spi, priv);
 313
 314         return el15203000_probe_dt(priv);
 315 }
 316
 317 static int el15203000_remove(struct spi_device *spi)
 318 {
 319         struct el15203000 *priv = spi_get_drvdata(spi);
 320
 321         mutex_destroy(&priv->lock);
 322
 323         return 0;
 324 }
 325
 326 static const struct of_device_id el15203000_dt_ids[] = {
 327         { .compatible = "crane,el15203000", },
 328         {},
 329 };
 330
 331 MODULE_DEVICE_TABLE(of, el15203000_dt_ids);
 332
 333 static struct spi_driver el15203000_driver = {
 334         .probe          = el15203000_probe,
 335         .remove         = el15203000_remove,
 336         .driver = {
 337                 .name           = KBUILD_MODNAME,
 338                 .of_match_table = el15203000_dt_ids,
 339         },
 340 };
 341
 342 module_spi_driver(el15203000_driver);
 343
 344 MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>");
 345 MODULE_DESCRIPTION("el15203000 LED driver");
 346 MODULE_LICENSE("GPL v2");
 347 MODULE_ALIAS("spi:el15203000");