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