1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Chassis LCD/LED driver for HP-PARISC workstations 4 * 5 * (c) Copyright 2000 Red Hat Software 6 * (c) Copyright 2000 Helge Deller <hdeller@redhat.com> 7 * (c) Copyright 2001 Randolph Chung <tausq@debian.org> 8 * (c) Copyright 2000-2023 Helge Deller <deller@gmx.de> 9 * 10 * The control of the LEDs and LCDs on PARISC machines has to be done 11 * completely in software. 12 * 13 * The LEDs can be configured at runtime in /sys/class/leds/ 14 */ 15 16 #include <linux/module.h> 17 #include <linux/init.h> 18 #include <linux/types.h> 19 #include <linux/ioport.h> 20 #include <linux/utsname.h> 21 #include <linux/capability.h> 22 #include <linux/delay.h> 23 #include <linux/reboot.h> 24 #include <linux/uaccess.h> 25 #include <linux/leds.h> 26 #include <linux/platform_device.h> 27 28 #include <asm/io.h> 29 #include <asm/processor.h> 30 #include <asm/hardware.h> 31 #include <asm/param.h> /* HZ */ 32 #include <asm/led.h> 33 #include <asm/pdc.h> 34 35 #define LED_HAS_LCD 1 36 #define LED_HAS_LED 2 37 38 static unsigned char led_type; /* bitmask of LED_HAS_XXX */ 39 static unsigned char lastleds; /* LED state from most recent update */ 40 static unsigned char lcd_new_text; 41 static unsigned char lcd_text[20]; 42 static unsigned char lcd_no_led_support; /* KittyHawk doesn't support LED on its LCD */ 43 44 struct lcd_block { 45 unsigned char command; /* stores the command byte */ 46 unsigned char on; /* value for turning LED on */ 47 unsigned char off; /* value for turning LED off */ 48 }; 49 50 /* Structure returned by PDC_RETURN_CHASSIS_INFO */ 51 /* NOTE: we use unsigned long:16 two times, since the following member 52 lcd_cmd_reg_addr needs to be 64bit aligned on 64bit PA2.0-machines */ 53 struct pdc_chassis_lcd_info_ret_block { 54 unsigned long model:16; /* DISPLAY_MODEL_XXXX */ 55 unsigned long lcd_width:16; /* width of the LCD in chars (DISPLAY_MODEL_LCD only) */ 56 unsigned long lcd_cmd_reg_addr; /* ptr to LCD cmd-register & data ptr for LED */ 57 unsigned long lcd_data_reg_addr; /* ptr to LCD data-register (LCD only) */ 58 unsigned int min_cmd_delay; /* delay in uS after cmd-write (LCD only) */ 59 unsigned char reset_cmd1; /* command #1 for writing LCD string (LCD only) */ 60 unsigned char reset_cmd2; /* command #2 for writing LCD string (LCD only) */ 61 unsigned char act_enable; /* 0 = no activity (LCD only) */ 62 struct lcd_block heartbeat; 63 struct lcd_block disk_io; 64 struct lcd_block lan_rcv; 65 struct lcd_block lan_tx; 66 char _pad; 67 }; 68 69 70 /* LCD_CMD and LCD_DATA for KittyHawk machines */ 71 #define KITTYHAWK_LCD_CMD F_EXTEND(0xf0190000UL) 72 #define KITTYHAWK_LCD_DATA (KITTYHAWK_LCD_CMD + 1) 73 74 /* lcd_info is pre-initialized to the values needed to program KittyHawk LCD's 75 * HP seems to have used Sharp/Hitachi HD44780 LCDs most of the time. */ 76 static struct pdc_chassis_lcd_info_ret_block 77 lcd_info __attribute__((aligned(8))) = 78 { 79 .model = DISPLAY_MODEL_NONE, 80 .lcd_width = 16, 81 .lcd_cmd_reg_addr = KITTYHAWK_LCD_CMD, 82 .lcd_data_reg_addr = KITTYHAWK_LCD_DATA, 83 .min_cmd_delay = 80, 84 .reset_cmd1 = 0x80, 85 .reset_cmd2 = 0xc0, 86 }; 87 88 /* direct access to some of the lcd_info variables */ 89 #define LCD_CMD_REG lcd_info.lcd_cmd_reg_addr 90 #define LCD_DATA_REG lcd_info.lcd_data_reg_addr 91 #define LED_DATA_REG lcd_info.lcd_cmd_reg_addr /* LASI & ASP only */ 92 93 /* ptr to LCD/LED-specific function */ 94 static void (*led_func_ptr) (unsigned char); 95 96 97 static void lcd_print_now(void) 98 { 99 int i; 100 char *str = lcd_text; 101 102 if (lcd_info.model != DISPLAY_MODEL_LCD) 103 return; 104 105 if (!lcd_new_text) 106 return; 107 lcd_new_text = 0; 108 109 /* Set LCD Cursor to 1st character */ 110 gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG); 111 udelay(lcd_info.min_cmd_delay); 112 113 /* Print the string */ 114 for (i = 0; i < lcd_info.lcd_width; i++) { 115 gsc_writeb(*str ? *str++ : ' ', LCD_DATA_REG); 116 udelay(lcd_info.min_cmd_delay); 117 } 118 } 119 120 /** 121 * lcd_print() 122 * 123 * @str: string to show on the LCD. If NULL, print current string again. 124 * 125 * Displays the given string on the LCD-Display of newer machines. 126 */ 127 void lcd_print(const char *str) 128 { 129 /* copy display string to buffer for procfs */ 130 if (str) 131 strscpy(lcd_text, str, sizeof(lcd_text)); 132 lcd_new_text = 1; 133 134 /* print now if LCD without any LEDs */ 135 if (led_type == LED_HAS_LCD) 136 lcd_print_now(); 137 } 138 139 #define LED_DATA 0x01 /* data to shift (0:on 1:off) */ 140 #define LED_STROBE 0x02 /* strobe to clock data */ 141 142 /** 143 * led_ASP_driver() - LED driver for the ASP controller chip 144 * 145 * @leds: bitmap representing the LED status 146 */ 147 static void led_ASP_driver(unsigned char leds) 148 { 149 int i; 150 151 leds = ~leds; 152 for (i = 0; i < 8; i++) { 153 unsigned char value; 154 value = (leds & 0x80) >> 7; 155 gsc_writeb( value, LED_DATA_REG ); 156 gsc_writeb( value | LED_STROBE, LED_DATA_REG ); 157 leds <<= 1; 158 } 159 } 160 161 /** 162 * led_LASI_driver() - LED driver for the LASI controller chip 163 * 164 * @leds: bitmap representing the LED status 165 */ 166 static void led_LASI_driver(unsigned char leds) 167 { 168 leds = ~leds; 169 gsc_writeb( leds, LED_DATA_REG ); 170 } 171 172 /** 173 * led_LCD_driver() - LED & LCD driver for LCD chips 174 * 175 * @leds: bitmap representing the LED status 176 */ 177 static void led_LCD_driver(unsigned char leds) 178 { 179 static const unsigned char mask[4] = { 180 LED_HEARTBEAT, LED_DISK_IO, 181 LED_LAN_RCV, LED_LAN_TX }; 182 183 static struct lcd_block * const blockp[4] = { 184 &lcd_info.heartbeat, 185 &lcd_info.disk_io, 186 &lcd_info.lan_rcv, 187 &lcd_info.lan_tx 188 }; 189 static unsigned char latest_leds; 190 int i; 191 192 for (i = 0; i < 4; ++i) { 193 if ((leds & mask[i]) == (latest_leds & mask[i])) 194 continue; 195 196 gsc_writeb( blockp[i]->command, LCD_CMD_REG ); 197 udelay(lcd_info.min_cmd_delay); 198 199 gsc_writeb( leds & mask[i] ? blockp[i]->on : 200 blockp[i]->off, LCD_DATA_REG ); 201 udelay(lcd_info.min_cmd_delay); 202 } 203 latest_leds = leds; 204 205 lcd_print_now(); 206 } 207 208 209 /** 210 * lcd_system_halt() 211 * 212 * @nb: pointer to the notifier_block structure 213 * @event: the event (SYS_RESTART, SYS_HALT or SYS_POWER_OFF) 214 * @buf: pointer to a buffer (not used) 215 * 216 * Called by the reboot notifier chain at shutdown. Stops all 217 * LED/LCD activities. 218 */ 219 static int lcd_system_halt(struct notifier_block *nb, unsigned long event, void *buf) 220 { 221 const char *txt; 222 223 switch (event) { 224 case SYS_RESTART: txt = "SYSTEM RESTART"; 225 break; 226 case SYS_HALT: txt = "SYSTEM HALT"; 227 break; 228 case SYS_POWER_OFF: txt = "SYSTEM POWER OFF"; 229 break; 230 default: return NOTIFY_DONE; 231 } 232 233 lcd_print(txt); 234 235 return NOTIFY_OK; 236 } 237 238 static struct notifier_block lcd_system_halt_notifier = { 239 .notifier_call = lcd_system_halt, 240 }; 241 242 static void set_led(struct led_classdev *led_cdev, enum led_brightness brightness); 243 244 struct hppa_led { 245 struct led_classdev led_cdev; 246 unsigned char led_bit; 247 }; 248 #define to_hppa_led(d) container_of(d, struct hppa_led, led_cdev) 249 250 typedef void (*set_handler)(struct led_classdev *, enum led_brightness); 251 struct led_type { 252 const char *name; 253 set_handler handler; 254 const char *default_trigger; 255 }; 256 257 #define NUM_LEDS_PER_BOARD 8 258 struct hppa_drvdata { 259 struct hppa_led leds[NUM_LEDS_PER_BOARD]; 260 }; 261 262 static void set_led(struct led_classdev *led_cdev, enum led_brightness brightness) 263 { 264 struct hppa_led *p = to_hppa_led(led_cdev); 265 unsigned char led_bit = p->led_bit; 266 267 if (brightness == LED_OFF) 268 lastleds &= ~led_bit; 269 else 270 lastleds |= led_bit; 271 272 if (led_func_ptr) 273 led_func_ptr(lastleds); 274 } 275 276 277 static int hppa_led_generic_probe(struct platform_device *pdev, 278 struct led_type *types) 279 { 280 struct hppa_drvdata *p; 281 int i, err; 282 283 p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL); 284 if (!p) 285 return -ENOMEM; 286 287 for (i = 0; i < NUM_LEDS_PER_BOARD; i++) { 288 struct led_classdev *lp = &p->leds[i].led_cdev; 289 290 p->leds[i].led_bit = BIT(i); 291 lp->name = types[i].name; 292 lp->brightness = LED_FULL; 293 lp->brightness_set = types[i].handler; 294 lp->default_trigger = types[i].default_trigger; 295 err = led_classdev_register(&pdev->dev, lp); 296 if (err) { 297 dev_err(&pdev->dev, "Could not register %s LED\n", 298 lp->name); 299 for (i--; i >= 0; i--) 300 led_classdev_unregister(&p->leds[i].led_cdev); 301 return err; 302 } 303 } 304 305 platform_set_drvdata(pdev, p); 306 307 return 0; 308 } 309 310 static void platform_led_remove(struct platform_device *pdev) 311 { 312 struct hppa_drvdata *p = platform_get_drvdata(pdev); 313 int i; 314 315 for (i = 0; i < NUM_LEDS_PER_BOARD; i++) 316 led_classdev_unregister(&p->leds[i].led_cdev); 317 } 318 319 static struct led_type mainboard_led_types[NUM_LEDS_PER_BOARD] = { 320 { 321 .name = "platform-lan-tx", 322 .handler = set_led, 323 .default_trigger = "tx", 324 }, 325 { 326 .name = "platform-lan-rx", 327 .handler = set_led, 328 .default_trigger = "rx", 329 }, 330 { 331 .name = "platform-disk", 332 .handler = set_led, 333 .default_trigger = "disk-activity", 334 }, 335 { 336 .name = "platform-heartbeat", 337 .handler = set_led, 338 .default_trigger = "heartbeat", 339 }, 340 { 341 .name = "platform-LED4", 342 .handler = set_led, 343 .default_trigger = "panic", 344 }, 345 { 346 .name = "platform-LED5", 347 .handler = set_led, 348 .default_trigger = "panic", 349 }, 350 { 351 .name = "platform-LED6", 352 .handler = set_led, 353 .default_trigger = "panic", 354 }, 355 { 356 .name = "platform-LED7", 357 .handler = set_led, 358 .default_trigger = "panic", 359 }, 360 }; 361 362 static int platform_led_probe(struct platform_device *pdev) 363 { 364 return hppa_led_generic_probe(pdev, mainboard_led_types); 365 } 366 367 MODULE_ALIAS("platform:platform-leds"); 368 369 static struct platform_driver hppa_mainboard_led_driver = { 370 .probe = platform_led_probe, 371 .remove = platform_led_remove, 372 .driver = { 373 .name = "platform-leds", 374 }, 375 }; 376 377 static struct platform_driver * const drivers[] = { 378 &hppa_mainboard_led_driver, 379 }; 380 381 static struct platform_device platform_leds = { 382 .name = "platform-leds", 383 }; 384 385 /** 386 * register_led_driver() 387 * 388 * @model: model type, one of the DISPLAY_MODEL_XXXX values 389 * @cmd_reg: physical address of cmd register for the LED/LCD 390 * @data_reg: physical address of data register for the LED/LCD 391 * 392 * Registers a chassis LED or LCD which should be driven by this driver. 393 * Only PDC-based, LASI- or ASP-style LEDs and LCDs are supported. 394 */ 395 int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg) 396 { 397 if (led_func_ptr || !data_reg) 398 return 1; 399 400 /* No LEDs when running in QEMU */ 401 if (running_on_qemu) 402 return 1; 403 404 lcd_info.model = model; /* store the values */ 405 LCD_CMD_REG = (cmd_reg == LED_CMD_REG_NONE) ? 0 : cmd_reg; 406 407 switch (lcd_info.model) { 408 case DISPLAY_MODEL_LCD: 409 LCD_DATA_REG = data_reg; 410 pr_info("led: LCD display at %#lx and %#lx\n", 411 LCD_CMD_REG , LCD_DATA_REG); 412 led_func_ptr = led_LCD_driver; 413 if (lcd_no_led_support) 414 led_type = LED_HAS_LCD; 415 else 416 led_type = LED_HAS_LCD | LED_HAS_LED; 417 break; 418 419 case DISPLAY_MODEL_LASI: 420 LED_DATA_REG = data_reg; 421 led_func_ptr = led_LASI_driver; 422 pr_info("led: LED display at %#lx\n", LED_DATA_REG); 423 led_type = LED_HAS_LED; 424 break; 425 426 case DISPLAY_MODEL_OLD_ASP: 427 LED_DATA_REG = data_reg; 428 led_func_ptr = led_ASP_driver; 429 pr_info("led: LED (ASP-style) display at %#lx\n", 430 LED_DATA_REG); 431 led_type = LED_HAS_LED; 432 break; 433 434 default: 435 pr_err("led: Unknown LCD/LED model type %d\n", lcd_info.model); 436 return 1; 437 } 438 439 platform_register_drivers(drivers, ARRAY_SIZE(drivers)); 440 441 return register_reboot_notifier(&lcd_system_halt_notifier); 442 } 443 444 /** 445 * early_led_init() 446 * 447 * early_led_init() is called early in the bootup-process and asks the 448 * PDC for an usable chassis LCD or LED. If the PDC doesn't return any 449 * info, then a LED might be detected by the LASI or ASP drivers later. 450 * KittyHawk machines have often a buggy PDC, so that we explicitly check 451 * for those machines here. 452 */ 453 static int __init early_led_init(void) 454 { 455 struct pdc_chassis_info chassis_info; 456 int ret; 457 458 scnprintf(lcd_text, sizeof(lcd_text), 459 "Linux %s", init_utsname()->release); 460 lcd_new_text = 1; 461 462 /* Work around the buggy PDC of KittyHawk-machines */ 463 switch (CPU_HVERSION) { 464 case 0x580: /* KittyHawk DC2-100 (K100) */ 465 case 0x581: /* KittyHawk DC3-120 (K210) */ 466 case 0x582: /* KittyHawk DC3 100 (K400) */ 467 case 0x583: /* KittyHawk DC3 120 (K410) */ 468 case 0x58B: /* KittyHawk DC2 100 (K200) */ 469 pr_info("LCD on KittyHawk-Machine found.\n"); 470 lcd_info.model = DISPLAY_MODEL_LCD; 471 /* KittyHawk has no LED support on its LCD, so skip LED detection */ 472 lcd_no_led_support = 1; 473 goto found; /* use the preinitialized values of lcd_info */ 474 } 475 476 /* initialize the struct, so that we can check for valid return values */ 477 chassis_info.actcnt = chassis_info.maxcnt = 0; 478 479 ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info)); 480 if (ret != PDC_OK) { 481 not_found: 482 lcd_info.model = DISPLAY_MODEL_NONE; 483 return 1; 484 } 485 486 /* check the results. Some machines have a buggy PDC */ 487 if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt) 488 goto not_found; 489 490 switch (lcd_info.model) { 491 case DISPLAY_MODEL_LCD: /* LCD display */ 492 if (chassis_info.actcnt < 493 offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1) 494 goto not_found; 495 if (!lcd_info.act_enable) { 496 /* PDC tells LCD should not be used. */ 497 goto not_found; 498 } 499 break; 500 501 case DISPLAY_MODEL_NONE: /* no LED or LCD available */ 502 goto not_found; 503 504 case DISPLAY_MODEL_LASI: /* Lasi style 8 bit LED display */ 505 if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32) 506 goto not_found; 507 break; 508 509 default: 510 pr_warn("PDC reported unknown LCD/LED model %d\n", 511 lcd_info.model); 512 goto not_found; 513 } 514 515 found: 516 /* register the LCD/LED driver */ 517 return register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG); 518 } 519 arch_initcall(early_led_init); 520 521 /** 522 * register_led_regions() 523 * 524 * Register_led_regions() registers the LCD/LED regions for /procfs. 525 * At bootup - where the initialisation of the LCD/LED often happens 526 * not all internal structures of request_region() are properly set up, 527 * so that we delay the led-registration until after busdevices_init() 528 * has been executed. 529 */ 530 static void __init register_led_regions(void) 531 { 532 switch (lcd_info.model) { 533 case DISPLAY_MODEL_LCD: 534 request_mem_region((unsigned long)LCD_CMD_REG, 1, "lcd_cmd"); 535 request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data"); 536 break; 537 case DISPLAY_MODEL_LASI: 538 case DISPLAY_MODEL_OLD_ASP: 539 request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data"); 540 break; 541 } 542 } 543 544 static int __init startup_leds(void) 545 { 546 if (platform_device_register(&platform_leds)) 547 printk(KERN_INFO "LED: failed to register LEDs\n"); 548 register_led_regions(); 549 return 0; 550 } 551 device_initcall(startup_leds); 552