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", ®)) 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"); 491