drivers/leds/leds-bcm6328.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Driver for BCM6328 memory-mapped LEDs, based on leds-syscon.c
   4  *
   5  * Copyright 2015 Álvaro Fernández Rojas <noltari@gmail.com>
   6  * Copyright 2015 Jonas Gorski <jogo@openwrt.org>
   7  */
   8 #include <linux/io.h>
   9 #include <linux/leds.h>
  10 #include <linux/module.h>
  11 #include <linux/of.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/spinlock.h>
  14
  15 #define BCM6328_REG_INIT                0x00
  16 #define BCM6328_REG_MODE_HI             0x04
  17 #define BCM6328_REG_MODE_LO             0x08
  18 #define BCM6328_REG_HWDIS               0x0c
  19 #define BCM6328_REG_STROBE              0x10
  20 #define BCM6328_REG_LNKACTSEL_HI        0x14
  21 #define BCM6328_REG_LNKACTSEL_LO        0x18
  22 #define BCM6328_REG_RBACK               0x1c
  23 #define BCM6328_REG_SERMUX              0x20
  24
  25 #define BCM6328_LED_MAX_COUNT           24
  26 #define BCM6328_LED_DEF_DELAY           500
  27
  28 #define BCM6328_LED_BLINK_DELAYS        2
  29 #define BCM6328_LED_BLINK_MS            20
  30
  31 #define BCM6328_LED_BLINK_MASK          0x3f
  32 #define BCM6328_LED_BLINK1_SHIFT        0
  33 #define BCM6328_LED_BLINK1_MASK         (BCM6328_LED_BLINK_MASK << \
  34                                          BCM6328_LED_BLINK1_SHIFT)
  35 #define BCM6328_LED_BLINK2_SHIFT        6
  36 #define BCM6328_LED_BLINK2_MASK         (BCM6328_LED_BLINK_MASK << \
  37                                          BCM6328_LED_BLINK2_SHIFT)
  38 #define BCM6328_SERIAL_LED_EN           BIT(12)
  39 #define BCM6328_SERIAL_LED_MUX          BIT(13)
  40 #define BCM6328_SERIAL_LED_CLK_NPOL     BIT(14)
  41 #define BCM6328_SERIAL_LED_DATA_PPOL    BIT(15)
  42 #define BCM6328_SERIAL_LED_SHIFT_DIR    BIT(16)
  43 #define BCM6328_LED_SHIFT_TEST          BIT(30)
  44 #define BCM6328_LED_TEST                BIT(31)
  45 #define BCM6328_INIT_MASK               (BCM6328_SERIAL_LED_EN | \
  46                                          BCM6328_SERIAL_LED_MUX | \
  47                                          BCM6328_SERIAL_LED_CLK_NPOL | \
  48                                          BCM6328_SERIAL_LED_DATA_PPOL | \
  49                                          BCM6328_SERIAL_LED_SHIFT_DIR)
  50
  51 #define BCM6328_LED_MODE_MASK           3
  52 #define BCM6328_LED_MODE_ON             0
  53 #define BCM6328_LED_MODE_BLINK1         1
  54 #define BCM6328_LED_MODE_BLINK2         2
  55 #define BCM6328_LED_MODE_OFF            3
  56 #define BCM6328_LED_SHIFT(X)            ((X) << 1)
  57
  58 /**
  59  * struct bcm6328_led - state container for bcm6328 based LEDs
  60  * @cdev: LED class device for this LED
  61  * @mem: memory resource
  62  * @lock: memory lock
  63  * @pin: LED pin number
  64  * @blink_leds: blinking LEDs
  65  * @blink_delay: blinking delay
  66  * @active_low: LED is active low
  67  */
  68 struct bcm6328_led {
  69         struct led_classdev cdev;
  70         void __iomem *mem;
  71         spinlock_t *lock;
  72         unsigned long pin;
  73         unsigned long *blink_leds;
  74         unsigned long *blink_delay;
  75         bool active_low;
  76 };
  77
  78 static void bcm6328_led_write(void __iomem *reg, unsigned long data)
  79 {
  80 #ifdef CONFIG_CPU_BIG_ENDIAN
  81         iowrite32be(data, reg);
  82 #else
  83         writel(data, reg);
  84 #endif
  85 }
  86
  87 static unsigned long bcm6328_led_read(void __iomem *reg)
  88 {
  89 #ifdef CONFIG_CPU_BIG_ENDIAN
  90         return ioread32be(reg);
  91 #else
  92         return readl(reg);
  93 #endif
  94 }
  95
  96 /**
  97  * LEDMode 64 bits / 24 LEDs
  98  * bits [31:0] -> LEDs 8-23
  99  * bits [47:32] -> LEDs 0-7
 100  * bits [63:48] -> unused
 101  */
 102 static unsigned long bcm6328_pin2shift(unsigned long pin)
 103 {
 104         if (pin < 8)
 105                 return pin + 16; /* LEDs 0-7 (bits 47:32) */
 106         else
 107                 return pin - 8; /* LEDs 8-23 (bits 31:0) */
 108 }
 109
 110 static void bcm6328_led_mode(struct bcm6328_led *led, unsigned long value)
 111 {
 112         void __iomem *mode;
 113         unsigned long val, shift;
 114
 115         shift = bcm6328_pin2shift(led->pin);
 116         if (shift / 16)
 117                 mode = led->mem + BCM6328_REG_MODE_HI;
 118         else
 119                 mode = led->mem + BCM6328_REG_MODE_LO;
 120
 121         val = bcm6328_led_read(mode);
 122         val &= ~(BCM6328_LED_MODE_MASK << BCM6328_LED_SHIFT(shift % 16));
 123         val |= (value << BCM6328_LED_SHIFT(shift % 16));
 124         bcm6328_led_write(mode, val);
 125 }
 126
 127 static void bcm6328_led_set(struct led_classdev *led_cdev,
 128                             enum led_brightness value)
 129 {
 130         struct bcm6328_led *led =
 131                 container_of(led_cdev, struct bcm6328_led, cdev);
 132         unsigned long flags;
 133
 134         spin_lock_irqsave(led->lock, flags);
 135
 136         /* Remove LED from cached HW blinking intervals */
 137         led->blink_leds[0] &= ~BIT(led->pin);
 138         led->blink_leds[1] &= ~BIT(led->pin);
 139
 140         /* Set LED on/off */
 141         if ((led->active_low && value == LED_OFF) ||
 142             (!led->active_low && value != LED_OFF))
 143                 bcm6328_led_mode(led, BCM6328_LED_MODE_ON);
 144         else
 145                 bcm6328_led_mode(led, BCM6328_LED_MODE_OFF);
 146
 147         spin_unlock_irqrestore(led->lock, flags);
 148 }
 149
 150 static unsigned long bcm6328_blink_delay(unsigned long delay)
 151 {
 152         unsigned long bcm6328_delay;
 153
 154         bcm6328_delay = delay + BCM6328_LED_BLINK_MS / 2;
 155         bcm6328_delay = bcm6328_delay / BCM6328_LED_BLINK_MS;
 156         if (bcm6328_delay == 0)
 157                 bcm6328_delay = 1;
 158
 159         return bcm6328_delay;
 160 }
 161
 162 static int bcm6328_blink_set(struct led_classdev *led_cdev,
 163                              unsigned long *delay_on, unsigned long *delay_off)
 164 {
 165         struct bcm6328_led *led =
 166                 container_of(led_cdev, struct bcm6328_led, cdev);
 167         unsigned long delay, flags;
 168         int rc;
 169
 170         if (!*delay_on)
 171                 *delay_on = BCM6328_LED_DEF_DELAY;
 172         if (!*delay_off)
 173                 *delay_off = BCM6328_LED_DEF_DELAY;
 174
 175         delay = bcm6328_blink_delay(*delay_on);
 176         if (delay != bcm6328_blink_delay(*delay_off)) {
 177                 dev_dbg(led_cdev->dev,
 178                         "fallback to soft blinking (delay_on != delay_off)\n");
 179                 return -EINVAL;
 180         }
 181
 182         if (delay > BCM6328_LED_BLINK_MASK) {
 183                 dev_dbg(led_cdev->dev,
 184                         "fallback to soft blinking (delay > %ums)\n",
 185                         BCM6328_LED_BLINK_MASK * BCM6328_LED_BLINK_MS);
 186                 return -EINVAL;
 187         }
 188
 189         spin_lock_irqsave(led->lock, flags);
 190         /*
 191          * Check if any of the two configurable HW blinking intervals is
 192          * available:
 193          *   1. No LEDs assigned to the HW blinking interval.
 194          *   2. Only this LED is assigned to the HW blinking interval.
 195          *   3. LEDs with the same delay assigned.
 196          */
 197         if (led->blink_leds[0] == 0 ||
 198             led->blink_leds[0] == BIT(led->pin) ||
 199             led->blink_delay[0] == delay) {
 200                 unsigned long val;
 201
 202                 /* Add LED to the first HW blinking interval cache */
 203                 led->blink_leds[0] |= BIT(led->pin);
 204
 205                 /* Remove LED from the second HW blinking interval cache */
 206                 led->blink_leds[1] &= ~BIT(led->pin);
 207
 208                 /* Cache first HW blinking interval delay */
 209                 led->blink_delay[0] = delay;
 210
 211                 /* Update the delay for the first HW blinking interval */
 212                 val = bcm6328_led_read(led->mem + BCM6328_REG_INIT);
 213                 val &= ~BCM6328_LED_BLINK1_MASK;
 214                 val |= (delay << BCM6328_LED_BLINK1_SHIFT);
 215                 bcm6328_led_write(led->mem + BCM6328_REG_INIT, val);
 216
 217                 /* Set the LED to first HW blinking interval */
 218                 bcm6328_led_mode(led, BCM6328_LED_MODE_BLINK1);
 219
 220                 rc = 0;
 221         } else if (led->blink_leds[1] == 0 ||
 222                    led->blink_leds[1] == BIT(led->pin) ||
 223                    led->blink_delay[1] == delay) {
 224                 unsigned long val;
 225
 226                 /* Remove LED from the first HW blinking interval */
 227                 led->blink_leds[0] &= ~BIT(led->pin);
 228
 229                 /* Add LED to the second HW blinking interval */
 230                 led->blink_leds[1] |= BIT(led->pin);
 231
 232                 /* Cache second HW blinking interval delay */
 233                 led->blink_delay[1] = delay;
 234
 235                 /* Update the delay for the second HW blinking interval */
 236                 val = bcm6328_led_read(led->mem + BCM6328_REG_INIT);
 237                 val &= ~BCM6328_LED_BLINK2_MASK;
 238                 val |= (delay << BCM6328_LED_BLINK2_SHIFT);
 239                 bcm6328_led_write(led->mem + BCM6328_REG_INIT, val);
 240
 241                 /* Set the LED to second HW blinking interval */
 242                 bcm6328_led_mode(led, BCM6328_LED_MODE_BLINK2);
 243
 244                 rc = 0;
 245         } else {
 246                 dev_dbg(led_cdev->dev,
 247                         "fallback to soft blinking (delay already set)\n");
 248                 rc = -EINVAL;
 249         }
 250         spin_unlock_irqrestore(led->lock, flags);
 251
 252         return rc;
 253 }
 254
 255 static int bcm6328_hwled(struct device *dev, struct device_node *nc, u32 reg,
 256                          void __iomem *mem, spinlock_t *lock)
 257 {
 258         int i, cnt;
 259         unsigned long flags, val;
 260
 261         spin_lock_irqsave(lock, flags);
 262         val = bcm6328_led_read(mem + BCM6328_REG_HWDIS);
 263         val &= ~BIT(reg);
 264         bcm6328_led_write(mem + BCM6328_REG_HWDIS, val);
 265         spin_unlock_irqrestore(lock, flags);
 266
 267         /* Only LEDs 0-7 can be activity/link controlled */
 268         if (reg >= 8)
 269                 return 0;
 270
 271         cnt = of_property_count_elems_of_size(nc, "brcm,link-signal-sources",
 272                                               sizeof(u32));
 273         for (i = 0; i < cnt; i++) {
 274                 u32 sel;
 275                 void __iomem *addr;
 276
 277                 if (reg < 4)
 278                         addr = mem + BCM6328_REG_LNKACTSEL_LO;
 279                 else
 280                         addr = mem + BCM6328_REG_LNKACTSEL_HI;
 281
 282                 of_property_read_u32_index(nc, "brcm,link-signal-sources", i,
 283                                            &sel);
 284
 285                 if (reg / 4 != sel / 4) {
 286                         dev_warn(dev, "invalid link signal source\n");
 287                         continue;
 288                 }
 289
 290                 spin_lock_irqsave(lock, flags);
 291                 val = bcm6328_led_read(addr);
 292                 val |= (BIT(reg % 4) << (((sel % 4) * 4) + 16));
 293                 bcm6328_led_write(addr, val);
 294                 spin_unlock_irqrestore(lock, flags);
 295         }
 296
 297         cnt = of_property_count_elems_of_size(nc,
 298                                               "brcm,activity-signal-sources",
 299                                               sizeof(u32));
 300         for (i = 0; i < cnt; i++) {
 301                 u32 sel;
 302                 void __iomem *addr;
 303
 304                 if (reg < 4)
 305                         addr = mem + BCM6328_REG_LNKACTSEL_LO;
 306                 else
 307                         addr = mem + BCM6328_REG_LNKACTSEL_HI;
 308
 309                 of_property_read_u32_index(nc, "brcm,activity-signal-sources",
 310                                            i, &sel);
 311
 312                 if (reg / 4 != sel / 4) {
 313                         dev_warn(dev, "invalid activity signal source\n");
 314                         continue;
 315                 }
 316
 317                 spin_lock_irqsave(lock, flags);
 318                 val = bcm6328_led_read(addr);
 319                 val |= (BIT(reg % 4) << ((sel % 4) * 4));
 320                 bcm6328_led_write(addr, val);
 321                 spin_unlock_irqrestore(lock, flags);
 322         }
 323
 324         return 0;
 325 }
 326
 327 static int bcm6328_led(struct device *dev, struct device_node *nc, u32 reg,
 328                        void __iomem *mem, spinlock_t *lock,
 329                        unsigned long *blink_leds, unsigned long *blink_delay)
 330 {
 331         struct bcm6328_led *led;
 332         const char *state;
 333         int rc;
 334
 335         led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
 336         if (!led)
 337                 return -ENOMEM;
 338
 339         led->pin = reg;
 340         led->mem = mem;
 341         led->lock = lock;
 342         led->blink_leds = blink_leds;
 343         led->blink_delay = blink_delay;
 344
 345         if (of_property_read_bool(nc, "active-low"))
 346                 led->active_low = true;
 347
 348         led->cdev.name = of_get_property(nc, "label", NULL) ? : nc->name;
 349         led->cdev.default_trigger = of_get_property(nc,
 350                                                     "linux,default-trigger",
 351                                                     NULL);
 352
 353         if (!of_property_read_string(nc, "default-state", &state)) {
 354                 if (!strcmp(state, "on")) {
 355                         led->cdev.brightness = LED_FULL;
 356                 } else if (!strcmp(state, "keep")) {
 357                         void __iomem *mode;
 358                         unsigned long val, shift;
 359
 360                         shift = bcm6328_pin2shift(led->pin);
 361                         if (shift / 16)
 362                                 mode = mem + BCM6328_REG_MODE_HI;
 363                         else
 364                                 mode = mem + BCM6328_REG_MODE_LO;
 365
 366                         val = bcm6328_led_read(mode) >>
 367                               BCM6328_LED_SHIFT(shift % 16);
 368                         val &= BCM6328_LED_MODE_MASK;
 369                         if ((led->active_low && val == BCM6328_LED_MODE_OFF) ||
 370                             (!led->active_low && val == BCM6328_LED_MODE_ON))
 371                                 led->cdev.brightness = LED_FULL;
 372                         else
 373                                 led->cdev.brightness = LED_OFF;
 374                 } else {
 375                         led->cdev.brightness = LED_OFF;
 376                 }
 377         } else {
 378                 led->cdev.brightness = LED_OFF;
 379         }
 380
 381         bcm6328_led_set(&led->cdev, led->cdev.brightness);
 382
 383         led->cdev.brightness_set = bcm6328_led_set;
 384         led->cdev.blink_set = bcm6328_blink_set;
 385
 386         rc = led_classdev_register(dev, &led->cdev);
 387         if (rc < 0)
 388                 return rc;
 389
 390         dev_dbg(dev, "registered LED %s\n", led->cdev.name);
 391
 392         return 0;
 393 }
 394
 395 static int bcm6328_leds_probe(struct platform_device *pdev)
 396 {
 397         struct device *dev = &pdev->dev;
 398         struct device_node *np = pdev->dev.of_node;
 399         struct device_node *child;
 400         void __iomem *mem;
 401         spinlock_t *lock; /* memory lock */
 402         unsigned long val, *blink_leds, *blink_delay;
 403
 404         mem = devm_platform_ioremap_resource(pdev, 0);
 405         if (IS_ERR(mem))
 406                 return PTR_ERR(mem);
 407
 408         lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
 409         if (!lock)
 410                 return -ENOMEM;
 411
 412         blink_leds = devm_kcalloc(dev, BCM6328_LED_BLINK_DELAYS,
 413                                   sizeof(*blink_leds), GFP_KERNEL);
 414         if (!blink_leds)
 415                 return -ENOMEM;
 416
 417         blink_delay = devm_kcalloc(dev, BCM6328_LED_BLINK_DELAYS,
 418                                    sizeof(*blink_delay), GFP_KERNEL);
 419         if (!blink_delay)
 420                 return -ENOMEM;
 421
 422         spin_lock_init(lock);
 423
 424         bcm6328_led_write(mem + BCM6328_REG_HWDIS, ~0);
 425         bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_HI, 0);
 426         bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_LO, 0);
 427
 428         val = bcm6328_led_read(mem + BCM6328_REG_INIT);
 429         val &= ~(BCM6328_INIT_MASK);
 430         if (of_property_read_bool(np, "brcm,serial-leds"))
 431                 val |= BCM6328_SERIAL_LED_EN;
 432         if (of_property_read_bool(np, "brcm,serial-mux"))
 433                 val |= BCM6328_SERIAL_LED_MUX;
 434         if (of_property_read_bool(np, "brcm,serial-clk-low"))
 435                 val |= BCM6328_SERIAL_LED_CLK_NPOL;
 436         if (!of_property_read_bool(np, "brcm,serial-dat-low"))
 437                 val |= BCM6328_SERIAL_LED_DATA_PPOL;
 438         if (!of_property_read_bool(np, "brcm,serial-shift-inv"))
 439                 val |= BCM6328_SERIAL_LED_SHIFT_DIR;
 440         bcm6328_led_write(mem + BCM6328_REG_INIT, val);
 441
 442         for_each_available_child_of_node(np, child) {
 443                 int rc;
 444                 u32 reg;
 445
 446                 if (of_property_read_u32(child, "reg", &reg))
 447                         continue;
 448
 449                 if (reg >= BCM6328_LED_MAX_COUNT) {
 450                         dev_err(dev, "invalid LED (%u >= %d)\n", reg,
 451                                 BCM6328_LED_MAX_COUNT);
 452                         continue;
 453                 }
 454
 455                 if (of_property_read_bool(child, "brcm,hardware-controlled"))
 456                         rc = bcm6328_hwled(dev, child, reg, mem, lock);
 457                 else
 458                         rc = bcm6328_led(dev, child, reg, mem, lock,
 459                                          blink_leds, blink_delay);
 460
 461                 if (rc < 0) {
 462                         of_node_put(child);
 463                         return rc;
 464                 }
 465         }
 466
 467         return 0;
 468 }
 469
 470 static const struct of_device_id bcm6328_leds_of_match[] = {
 471         { .compatible = "brcm,bcm6328-leds", },
 472         { },
 473 };
 474 MODULE_DEVICE_TABLE(of, bcm6328_leds_of_match);
 475
 476 static struct platform_driver bcm6328_leds_driver = {
 477         .probe = bcm6328_leds_probe,
 478         .driver = {
 479                 .name = "leds-bcm6328",
 480                 .of_match_table = bcm6328_leds_of_match,
 481         },
 482 };
 483
 484 module_platform_driver(bcm6328_leds_driver);
 485
 486 MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
 487 MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
 488 MODULE_DESCRIPTION("LED driver for BCM6328 controllers");
 489 MODULE_LICENSE("GPL v2");
 490 MODULE_ALIAS("platform:leds-bcm6328");