leds-bcm6328.c (13041B)
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 */ 68struct 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 78static 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 87static 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 */ 102static 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 110static 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 127static 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 150static 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 162static 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 255static 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 327static 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 led_init_data init_data = {}; 332 struct bcm6328_led *led; 333 const char *state; 334 int rc; 335 336 led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL); 337 if (!led) 338 return -ENOMEM; 339 340 led->pin = reg; 341 led->mem = mem; 342 led->lock = lock; 343 led->blink_leds = blink_leds; 344 led->blink_delay = blink_delay; 345 346 if (of_property_read_bool(nc, "active-low")) 347 led->active_low = true; 348 349 if (!of_property_read_string(nc, "default-state", &state)) { 350 if (!strcmp(state, "on")) { 351 led->cdev.brightness = LED_FULL; 352 } else if (!strcmp(state, "keep")) { 353 void __iomem *mode; 354 unsigned long val, shift; 355 356 shift = bcm6328_pin2shift(led->pin); 357 if (shift / 16) 358 mode = mem + BCM6328_REG_MODE_HI; 359 else 360 mode = mem + BCM6328_REG_MODE_LO; 361 362 val = bcm6328_led_read(mode) >> 363 BCM6328_LED_SHIFT(shift % 16); 364 val &= BCM6328_LED_MODE_MASK; 365 if ((led->active_low && val == BCM6328_LED_MODE_OFF) || 366 (!led->active_low && val == BCM6328_LED_MODE_ON)) 367 led->cdev.brightness = LED_FULL; 368 else 369 led->cdev.brightness = LED_OFF; 370 } else { 371 led->cdev.brightness = LED_OFF; 372 } 373 } else { 374 led->cdev.brightness = LED_OFF; 375 } 376 377 bcm6328_led_set(&led->cdev, led->cdev.brightness); 378 379 led->cdev.brightness_set = bcm6328_led_set; 380 led->cdev.blink_set = bcm6328_blink_set; 381 init_data.fwnode = of_fwnode_handle(nc); 382 383 rc = devm_led_classdev_register_ext(dev, &led->cdev, &init_data); 384 if (rc < 0) 385 return rc; 386 387 dev_dbg(dev, "registered LED %s\n", led->cdev.name); 388 389 return 0; 390} 391 392static int bcm6328_leds_probe(struct platform_device *pdev) 393{ 394 struct device *dev = &pdev->dev; 395 struct device_node *np = dev_of_node(&pdev->dev); 396 struct device_node *child; 397 void __iomem *mem; 398 spinlock_t *lock; /* memory lock */ 399 unsigned long val, *blink_leds, *blink_delay; 400 401 mem = devm_platform_ioremap_resource(pdev, 0); 402 if (IS_ERR(mem)) 403 return PTR_ERR(mem); 404 405 lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL); 406 if (!lock) 407 return -ENOMEM; 408 409 blink_leds = devm_kcalloc(dev, BCM6328_LED_BLINK_DELAYS, 410 sizeof(*blink_leds), GFP_KERNEL); 411 if (!blink_leds) 412 return -ENOMEM; 413 414 blink_delay = devm_kcalloc(dev, BCM6328_LED_BLINK_DELAYS, 415 sizeof(*blink_delay), GFP_KERNEL); 416 if (!blink_delay) 417 return -ENOMEM; 418 419 spin_lock_init(lock); 420 421 bcm6328_led_write(mem + BCM6328_REG_HWDIS, ~0); 422 bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_HI, 0); 423 bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_LO, 0); 424 425 val = bcm6328_led_read(mem + BCM6328_REG_INIT); 426 val &= ~(BCM6328_INIT_MASK); 427 if (of_property_read_bool(np, "brcm,serial-leds")) 428 val |= BCM6328_SERIAL_LED_EN; 429 if (of_property_read_bool(np, "brcm,serial-mux")) 430 val |= BCM6328_SERIAL_LED_MUX; 431 if (of_property_read_bool(np, "brcm,serial-clk-low")) 432 val |= BCM6328_SERIAL_LED_CLK_NPOL; 433 if (!of_property_read_bool(np, "brcm,serial-dat-low")) 434 val |= BCM6328_SERIAL_LED_DATA_PPOL; 435 if (!of_property_read_bool(np, "brcm,serial-shift-inv")) 436 val |= BCM6328_SERIAL_LED_SHIFT_DIR; 437 bcm6328_led_write(mem + BCM6328_REG_INIT, val); 438 439 for_each_available_child_of_node(np, child) { 440 int rc; 441 u32 reg; 442 443 if (of_property_read_u32(child, "reg", ®)) 444 continue; 445 446 if (reg >= BCM6328_LED_MAX_COUNT) { 447 dev_err(dev, "invalid LED (%u >= %d)\n", reg, 448 BCM6328_LED_MAX_COUNT); 449 continue; 450 } 451 452 if (of_property_read_bool(child, "brcm,hardware-controlled")) 453 rc = bcm6328_hwled(dev, child, reg, mem, lock); 454 else 455 rc = bcm6328_led(dev, child, reg, mem, lock, 456 blink_leds, blink_delay); 457 458 if (rc < 0) { 459 of_node_put(child); 460 return rc; 461 } 462 } 463 464 return 0; 465} 466 467static const struct of_device_id bcm6328_leds_of_match[] = { 468 { .compatible = "brcm,bcm6328-leds", }, 469 { }, 470}; 471MODULE_DEVICE_TABLE(of, bcm6328_leds_of_match); 472 473static struct platform_driver bcm6328_leds_driver = { 474 .probe = bcm6328_leds_probe, 475 .driver = { 476 .name = "leds-bcm6328", 477 .of_match_table = bcm6328_leds_of_match, 478 }, 479}; 480 481module_platform_driver(bcm6328_leds_driver); 482 483MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>"); 484MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>"); 485MODULE_DESCRIPTION("LED driver for BCM6328 controllers"); 486MODULE_LICENSE("GPL v2"); 487MODULE_ALIAS("platform:leds-bcm6328");