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