drivers/leds/leds-bcm6328.c

   1 /*
   2  * Driver for BCM6328 memory-mapped LEDs, based on leds-syscon.c
   3  *
   4  * Copyright 2015 Álvaro Fernández Rojas <noltari@gmail.com>
   5  * Copyright 2015 Jonas Gorski <jogo@openwrt.org>
   6  *
   7  * This program is free software; you can redistribute  it and/or modify it
   8  * under  the terms of  the GNU General  Public License as published by the
   9  * Free Software Foundation;  either version 2 of the  License, or (at your
  10  * option) any later version.
  11  */
  12 #include <linux/io.h>
  13 #include <linux/leds.h>
  14 #include <linux/module.h>
  15 #include <linux/of.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/spinlock.h>
  18
  19 #define BCM6328_REG_INIT                0x00
  20 #define BCM6328_REG_MODE_HI             0x04
  21 #define BCM6328_REG_MODE_LO             0x08
  22 #define BCM6328_REG_HWDIS               0x0c
  23 #define BCM6328_REG_STROBE              0x10
  24 #define BCM6328_REG_LNKACTSEL_HI        0x14
  25 #define BCM6328_REG_LNKACTSEL_LO        0x18
  26 #define BCM6328_REG_RBACK               0x1c
  27 #define BCM6328_REG_SERMUX              0x20
  28
  29 #define BCM6328_LED_MAX_COUNT           24
  30 #define BCM6328_LED_DEF_DELAY           500
  31 #define BCM6328_LED_INTERVAL_MS         20
  32
  33 #define BCM6328_LED_INTV_MASK           0x3f
  34 #define BCM6328_LED_FAST_INTV_SHIFT     6
  35 #define BCM6328_LED_FAST_INTV_MASK      (BCM6328_LED_INTV_MASK << \
  36                                          BCM6328_LED_FAST_INTV_SHIFT)
  37 #define BCM6328_SERIAL_LED_EN           BIT(12)
  38 #define BCM6328_SERIAL_LED_MUX          BIT(13)
  39 #define BCM6328_SERIAL_LED_CLK_NPOL     BIT(14)
  40 #define BCM6328_SERIAL_LED_DATA_PPOL    BIT(15)
  41 #define BCM6328_SERIAL_LED_SHIFT_DIR    BIT(16)
  42 #define BCM6328_LED_SHIFT_TEST          BIT(30)
  43 #define BCM6328_LED_TEST                BIT(31)
  44 #define BCM6328_INIT_MASK               (BCM6328_SERIAL_LED_EN | \
  45                                          BCM6328_SERIAL_LED_MUX  | \
  46                                          BCM6328_SERIAL_LED_CLK_NPOL | \
  47                                          BCM6328_SERIAL_LED_DATA_PPOL | \
  48                                          BCM6328_SERIAL_LED_SHIFT_DIR)
  49
  50 #define BCM6328_LED_MODE_MASK           3
  51 #define BCM6328_LED_MODE_OFF            0
  52 #define BCM6328_LED_MODE_FAST           1
  53 #define BCM6328_LED_MODE_BLINK          2
  54 #define BCM6328_LED_MODE_ON             3
  55 #define BCM6328_LED_SHIFT(X)            ((X) << 1)
  56
  57 /**
  58  * struct bcm6328_led - state container for bcm6328 based LEDs
  59  * @cdev: LED class device for this LED
  60  * @mem: memory resource
  61  * @lock: memory lock
  62  * @pin: LED pin number
  63  * @blink_leds: blinking LEDs
  64  * @blink_delay: blinking delay
  65  * @active_low: LED is active low
  66  */
  67 struct bcm6328_led {
  68         struct led_classdev cdev;
  69         void __iomem *mem;
  70         spinlock_t *lock;
  71         unsigned long pin;
  72         unsigned long *blink_leds;
  73         unsigned long *blink_delay;
  74         bool active_low;
  75 };
  76
  77 static void bcm6328_led_write(void __iomem *reg, unsigned long data)
  78 {
  79         iowrite32be(data, reg);
  80 }
  81
  82 static unsigned long bcm6328_led_read(void __iomem *reg)
  83 {
  84         return ioread32be(reg);
  85 }
  86
  87 /**
  88  * LEDMode 64 bits / 24 LEDs
  89  * bits [31:0] -> LEDs 8-23
  90  * bits [47:32] -> LEDs 0-7
  91  * bits [63:48] -> unused
  92  */
  93 static unsigned long bcm6328_pin2shift(unsigned long pin)
  94 {
  95         if (pin < 8)
  96                 return pin + 16; /* LEDs 0-7 (bits 47:32) */
  97         else
  98                 return pin - 8; /* LEDs 8-23 (bits 31:0) */
  99 }
 100
 101 static void bcm6328_led_mode(struct bcm6328_led *led, unsigned long value)
 102 {
 103         void __iomem *mode;
 104         unsigned long val, shift;
 105
 106         shift = bcm6328_pin2shift(led->pin);
 107         if (shift / 16)
 108                 mode = led->mem + BCM6328_REG_MODE_HI;
 109         else
 110                 mode = led->mem + BCM6328_REG_MODE_LO;
 111
 112         val = bcm6328_led_read(mode);
 113         val &= ~(BCM6328_LED_MODE_MASK << BCM6328_LED_SHIFT(shift % 16));
 114         val |= (value << BCM6328_LED_SHIFT(shift % 16));
 115         bcm6328_led_write(mode, val);
 116 }
 117
 118 static void bcm6328_led_set(struct led_classdev *led_cdev,
 119                             enum led_brightness value)
 120 {
 121         struct bcm6328_led *led =
 122                 container_of(led_cdev, struct bcm6328_led, cdev);
 123         unsigned long flags;
 124
 125         spin_lock_irqsave(led->lock, flags);
 126         *(led->blink_leds) &= ~BIT(led->pin);
 127         if ((led->active_low && value == LED_OFF) ||
 128             (!led->active_low && value != LED_OFF))
 129                 bcm6328_led_mode(led, BCM6328_LED_MODE_OFF);
 130         else
 131                 bcm6328_led_mode(led, BCM6328_LED_MODE_ON);
 132         spin_unlock_irqrestore(led->lock, flags);
 133 }
 134
 135 static int bcm6328_blink_set(struct led_classdev *led_cdev,
 136                              unsigned long *delay_on, unsigned long *delay_off)
 137 {
 138         struct bcm6328_led *led =
 139                 container_of(led_cdev, struct bcm6328_led, cdev);
 140         unsigned long delay, flags;
 141
 142         if (!*delay_on)
 143                 *delay_on = BCM6328_LED_DEF_DELAY;
 144         if (!*delay_off)
 145                 *delay_off = BCM6328_LED_DEF_DELAY;
 146
 147         if (*delay_on != *delay_off) {
 148                 dev_dbg(led_cdev->dev,
 149                         "fallback to soft blinking (delay_on != delay_off)\n");
 150                 return -EINVAL;
 151         }
 152
 153         delay = *delay_on / BCM6328_LED_INTERVAL_MS;
 154         if (delay == 0)
 155                 delay = 1;
 156         else if (delay > BCM6328_LED_INTV_MASK) {
 157                 dev_dbg(led_cdev->dev,
 158                         "fallback to soft blinking (delay > %ums)\n",
 159                         BCM6328_LED_INTV_MASK * BCM6328_LED_INTERVAL_MS);
 160                 return -EINVAL;
 161         }
 162
 163         spin_lock_irqsave(led->lock, flags);
 164         if (*(led->blink_leds) == 0 ||
 165             *(led->blink_leds) == BIT(led->pin) ||
 166             *(led->blink_delay) == delay) {
 167                 unsigned long val;
 168
 169                 *(led->blink_leds) |= BIT(led->pin);
 170                 *(led->blink_delay) = delay;
 171
 172                 val = bcm6328_led_read(led->mem + BCM6328_REG_INIT);
 173                 val &= ~BCM6328_LED_FAST_INTV_MASK;
 174                 val |= (delay << BCM6328_LED_FAST_INTV_SHIFT);
 175                 bcm6328_led_write(led->mem + BCM6328_REG_INIT, val);
 176
 177                 bcm6328_led_mode(led, BCM6328_LED_MODE_BLINK);
 178
 179                 spin_unlock_irqrestore(led->lock, flags);
 180         } else {
 181                 spin_unlock_irqrestore(led->lock, flags);
 182                 dev_dbg(led_cdev->dev,
 183                         "fallback to soft blinking (delay already set)\n");
 184                 return -EINVAL;
 185         }
 186
 187         return 0;
 188 }
 189
 190 static int bcm6328_hwled(struct device *dev, struct device_node *nc, u32 reg,
 191                          void __iomem *mem, spinlock_t *lock)
 192 {
 193         int i, cnt;
 194         unsigned long flags, val;
 195
 196         spin_lock_irqsave(lock, flags);
 197         val = bcm6328_led_read(mem + BCM6328_REG_HWDIS);
 198         val &= ~BIT(reg);
 199         bcm6328_led_write(mem + BCM6328_REG_HWDIS, val);
 200         spin_unlock_irqrestore(lock, flags);
 201
 202         /* Only LEDs 0-7 can be activity/link controlled */
 203         if (reg >= 8)
 204                 return 0;
 205
 206         cnt = of_property_count_elems_of_size(nc, "brcm,link-signal-sources",
 207                                               sizeof(u32));
 208         for (i = 0; i < cnt; i++) {
 209                 u32 sel;
 210                 void __iomem *addr;
 211
 212                 if (reg < 4)
 213                         addr = mem + BCM6328_REG_LNKACTSEL_LO;
 214                 else
 215                         addr = mem + BCM6328_REG_LNKACTSEL_HI;
 216
 217                 of_property_read_u32_index(nc, "brcm,link-signal-sources", i,
 218                                            &sel);
 219
 220                 if (reg / 4 != sel / 4) {
 221                         dev_warn(dev, "invalid link signal source\n");
 222                         continue;
 223                 }
 224
 225                 spin_lock_irqsave(lock, flags);
 226                 val = bcm6328_led_read(addr);
 227                 val |= (BIT(reg) << (((sel % 4) * 4) + 16));
 228                 bcm6328_led_write(addr, val);
 229                 spin_unlock_irqrestore(lock, flags);
 230         }
 231
 232         cnt = of_property_count_elems_of_size(nc,
 233                                               "brcm,activity-signal-sources",
 234                                               sizeof(u32));
 235         for (i = 0; i < cnt; i++) {
 236                 u32 sel;
 237                 void __iomem *addr;
 238
 239                 if (reg < 4)
 240                         addr = mem + BCM6328_REG_LNKACTSEL_LO;
 241                 else
 242                         addr = mem + BCM6328_REG_LNKACTSEL_HI;
 243
 244                 of_property_read_u32_index(nc, "brcm,activity-signal-sources",
 245                                            i, &sel);
 246
 247                 if (reg / 4 != sel / 4) {
 248                         dev_warn(dev, "invalid activity signal source\n");
 249                         continue;
 250                 }
 251
 252                 spin_lock_irqsave(lock, flags);
 253                 val = bcm6328_led_read(addr);
 254                 val |= (BIT(reg) << ((sel % 4) * 4));
 255                 bcm6328_led_write(addr, val);
 256                 spin_unlock_irqrestore(lock, flags);
 257         }
 258
 259         return 0;
 260 }
 261
 262 static int bcm6328_led(struct device *dev, struct device_node *nc, u32 reg,
 263                        void __iomem *mem, spinlock_t *lock,
 264                        unsigned long *blink_leds, unsigned long *blink_delay)
 265 {
 266         struct bcm6328_led *led;
 267         unsigned long flags;
 268         const char *state;
 269         int rc;
 270
 271         led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
 272         if (!led)
 273                 return -ENOMEM;
 274
 275         led->pin = reg;
 276         led->mem = mem;
 277         led->lock = lock;
 278         led->blink_leds = blink_leds;
 279         led->blink_delay = blink_delay;
 280
 281         if (of_property_read_bool(nc, "active-low"))
 282                 led->active_low = true;
 283
 284         led->cdev.name = of_get_property(nc, "label", NULL) ? : nc->name;
 285         led->cdev.default_trigger = of_get_property(nc,
 286                                                     "linux,default-trigger",
 287                                                     NULL);
 288
 289         spin_lock_irqsave(lock, flags);
 290         if (!of_property_read_string(nc, "default-state", &state)) {
 291                 if (!strcmp(state, "on")) {
 292                         led->cdev.brightness = LED_FULL;
 293                 } else if (!strcmp(state, "keep")) {
 294                         void __iomem *mode;
 295                         unsigned long val, shift;
 296
 297                         shift = bcm6328_pin2shift(led->pin);
 298                         if (shift / 16)
 299                                 mode = mem + BCM6328_REG_MODE_HI;
 300                         else
 301                                 mode = mem + BCM6328_REG_MODE_LO;
 302
 303                         val = bcm6328_led_read(mode) >>
 304                               BCM6328_LED_SHIFT(shift % 16);
 305                         val &= BCM6328_LED_MODE_MASK;
 306                         if ((led->active_low && val == BCM6328_LED_MODE_ON) ||
 307                             (!led->active_low && val == BCM6328_LED_MODE_OFF))
 308                                 led->cdev.brightness = LED_FULL;
 309                         else
 310                                 led->cdev.brightness = LED_OFF;
 311                 } else {
 312                         led->cdev.brightness = LED_OFF;
 313                 }
 314         } else {
 315                 led->cdev.brightness = LED_OFF;
 316         }
 317
 318         if ((led->active_low && led->cdev.brightness == LED_FULL) ||
 319             (!led->active_low && led->cdev.brightness == LED_OFF))
 320                 bcm6328_led_mode(led, BCM6328_LED_MODE_ON);
 321         else
 322                 bcm6328_led_mode(led, BCM6328_LED_MODE_OFF);
 323         spin_unlock_irqrestore(lock, flags);
 324
 325         led->cdev.brightness_set = bcm6328_led_set;
 326         led->cdev.blink_set = bcm6328_blink_set;
 327
 328         rc = led_classdev_register(dev, &led->cdev);
 329         if (rc < 0)
 330                 return rc;
 331
 332         dev_dbg(dev, "registered LED %s\n", led->cdev.name);
 333
 334         return 0;
 335 }
 336
 337 static int bcm6328_leds_probe(struct platform_device *pdev)
 338 {
 339         struct device *dev = &pdev->dev;
 340         struct device_node *np = pdev->dev.of_node;
 341         struct device_node *child;
 342         struct resource *mem_r;
 343         void __iomem *mem;
 344         spinlock_t *lock;
 345         unsigned long val, *blink_leds, *blink_delay;
 346
 347         mem_r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 348         if (!mem_r)
 349                 return -EINVAL;
 350
 351         mem = devm_ioremap_resource(dev, mem_r);
 352         if (IS_ERR(mem))
 353                 return PTR_ERR(mem);
 354
 355         lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
 356         if (!lock)
 357                 return -ENOMEM;
 358
 359         blink_leds = devm_kzalloc(dev, sizeof(*blink_leds), GFP_KERNEL);
 360         if (!blink_leds)
 361                 return -ENOMEM;
 362
 363         blink_delay = devm_kzalloc(dev, sizeof(*blink_delay), GFP_KERNEL);
 364         if (!blink_delay)
 365                 return -ENOMEM;
 366
 367         spin_lock_init(lock);
 368
 369         bcm6328_led_write(mem + BCM6328_REG_HWDIS, ~0);
 370         bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_HI, 0);
 371         bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_LO, 0);
 372
 373         val = bcm6328_led_read(mem + BCM6328_REG_INIT);
 374         val &= ~(BCM6328_INIT_MASK);
 375         if (of_property_read_bool(np, "brcm,serial-leds"))
 376                 val |= BCM6328_SERIAL_LED_EN;
 377         if (of_property_read_bool(np, "brcm,serial-mux"))
 378                 val |= BCM6328_SERIAL_LED_MUX;
 379         if (of_property_read_bool(np, "brcm,serial-clk-low"))
 380                 val |= BCM6328_SERIAL_LED_CLK_NPOL;
 381         if (!of_property_read_bool(np, "brcm,serial-dat-low"))
 382                 val |= BCM6328_SERIAL_LED_DATA_PPOL;
 383         if (!of_property_read_bool(np, "brcm,serial-shift-inv"))
 384                 val |= BCM6328_SERIAL_LED_SHIFT_DIR;
 385         bcm6328_led_write(mem + BCM6328_REG_INIT, val);
 386
 387         for_each_available_child_of_node(np, child) {
 388                 int rc;
 389                 u32 reg;
 390
 391                 if (of_property_read_u32(child, "reg", &reg))
 392                         continue;
 393
 394                 if (reg >= BCM6328_LED_MAX_COUNT) {
 395                         dev_err(dev, "invalid LED (%u >= %d)\n", reg,
 396                                 BCM6328_LED_MAX_COUNT);
 397                         continue;
 398                 }
 399
 400                 if (of_property_read_bool(child, "brcm,hardware-controlled"))
 401                         rc = bcm6328_hwled(dev, child, reg, mem, lock);
 402                 else
 403                         rc = bcm6328_led(dev, child, reg, mem, lock,
 404                                          blink_leds, blink_delay);
 405
 406                 if (rc < 0) {
 407                         of_node_put(child);
 408                         return rc;
 409                 }
 410         }
 411
 412         return 0;
 413 }
 414
 415 static const struct of_device_id bcm6328_leds_of_match[] = {
 416         { .compatible = "brcm,bcm6328-leds", },
 417         { },
 418 };
 419 MODULE_DEVICE_TABLE(of, bcm6328_leds_of_match);
 420
 421 static struct platform_driver bcm6328_leds_driver = {
 422         .probe = bcm6328_leds_probe,
 423         .driver = {
 424                 .name = "leds-bcm6328",
 425                 .of_match_table = bcm6328_leds_of_match,
 426         },
 427 };
 428
 429 module_platform_driver(bcm6328_leds_driver);
 430
 431 MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
 432 MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
 433 MODULE_DESCRIPTION("LED driver for BCM6328 controllers");
 434 MODULE_LICENSE("GPL v2");
 435 MODULE_ALIAS("platform:leds-bcm6328");