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_text_default[20]; 43 static unsigned char lcd_no_led_support; /* KittyHawk doesn't support LED on its LCD */ 44 45 struct lcd_block { 46 unsigned char command; /* stores the command byte */ 47 unsigned char on; /* value for turning LED on */ 48 unsigned char off; /* value for turning LED off */ 49 }; 50 51 /* Structure returned by PDC_RETURN_CHASSIS_INFO */ 52 /* NOTE: we use unsigned long:16 two times, since the following member 53 lcd_cmd_reg_addr needs to be 64bit aligned on 64bit PA2.0-machines */ 54 struct pdc_chassis_lcd_info_ret_block { 55 unsigned long model:16; /* DISPLAY_MODEL_XXXX */ 56 unsigned long lcd_width:16; /* width of the LCD in chars (DISPLAY_MODEL_LCD only) */ 57 unsigned long lcd_cmd_reg_addr; /* ptr to LCD cmd-register & data ptr for LED */ 58 unsigned long lcd_data_reg_addr; /* ptr to LCD data-register (LCD only) */ 59 unsigned int min_cmd_delay; /* delay in uS after cmd-write (LCD only) */ 60 unsigned char reset_cmd1; /* command #1 for writing LCD string (LCD only) */ 61 unsigned char reset_cmd2; /* command #2 for writing LCD string (LCD only) */ 62 unsigned char act_enable; /* 0 = no activity (LCD only) */ 63 struct lcd_block heartbeat; 64 struct lcd_block disk_io; 65 struct lcd_block lan_rcv; 66 struct lcd_block lan_tx; 67 char _pad; 68 }; 69 70 71 /* LCD_CMD and LCD_DATA for KittyHawk machines */ 72 #define KITTYHAWK_LCD_CMD F_EXTEND(0xf0190000UL) 73 #define KITTYHAWK_LCD_DATA (KITTYHAWK_LCD_CMD + 1) 74 75 /* lcd_info is pre-initialized to the values needed to program KittyHawk LCD's 76 * HP seems to have used Sharp/Hitachi HD44780 LCDs most of the time. */ 77 static struct pdc_chassis_lcd_info_ret_block 78 lcd_info __attribute__((aligned(8))) = 79 { 80 .model = DISPLAY_MODEL_NONE, 81 .lcd_width = 16, 82 .lcd_cmd_reg_addr = KITTYHAWK_LCD_CMD, 83 .lcd_data_reg_addr = KITTYHAWK_LCD_DATA, 84 .min_cmd_delay = 80, 85 .reset_cmd1 = 0x80, 86 .reset_cmd2 = 0xc0, 87 }; 88 89 /* direct access to some of the lcd_info variables */ 90 #define LCD_CMD_REG lcd_info.lcd_cmd_reg_addr 91 #define LCD_DATA_REG lcd_info.lcd_data_reg_addr 92 #define LED_DATA_REG lcd_info.lcd_cmd_reg_addr /* LASI & ASP only */ 93 94 /* ptr to LCD/LED-specific function */ 95 static void (*led_func_ptr) (unsigned char); 96 97 98 static void lcd_print_now(void) 99 { 100 int i; 101 char *str = lcd_text; 102 103 if (lcd_info.model != DISPLAY_MODEL_LCD) 104 return; 105 106 if (!lcd_new_text) 107 return; 108 lcd_new_text = 0; 109 110 /* Set LCD Cursor to 1st character */ 111 gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG); 112 udelay(lcd_info.min_cmd_delay); 113 114 /* Print the string */ 115 for (i = 0; i < lcd_info.lcd_width; i++) { 116 gsc_writeb(*str ? *str++ : ' ', LCD_DATA_REG); 117 udelay(lcd_info.min_cmd_delay); 118 } 119 } 120 121 /** 122 * lcd_print() 123 * 124 * @str: string to show on the LCD. If NULL, print current string again. 125 * 126 * Displays the given string on the LCD-Display of newer machines. 127 */ 128 void lcd_print(const char *str) 129 { 130 /* copy display string to buffer for procfs */ 131 if (str) 132 strscpy(lcd_text, str, sizeof(lcd_text)); 133 lcd_new_text = 1; 134 135 /* print now if LCD without any LEDs */ 136 if (led_type == LED_HAS_LCD) 137 lcd_print_now(); 138 } 139 140 #define LED_DATA 0x01 /* data to shift (0:on 1:off) */ 141 #define LED_STROBE 0x02 /* strobe to clock data */ 142 143 /** 144 * led_ASP_driver() - LED driver for the ASP controller chip 145 * 146 * @leds: bitmap representing the LED status 147 */ 148 static void led_ASP_driver(unsigned char leds) 149 { 150 int i; 151 152 leds = ~leds; 153 for (i = 0; i < 8; i++) { 154 unsigned char value; 155 value = (leds & 0x80) >> 7; 156 gsc_writeb( value, LED_DATA_REG ); 157 gsc_writeb( value | LED_STROBE, LED_DATA_REG ); 158 leds <<= 1; 159 } 160 } 161 162 /** 163 * led_LASI_driver() - LED driver for the LASI controller chip 164 * 165 * @leds: bitmap representing the LED status 166 */ 167 static void led_LASI_driver(unsigned char leds) 168 { 169 leds = ~leds; 170 gsc_writeb( leds, LED_DATA_REG ); 171 } 172 173 /** 174 * led_LCD_driver() - LED & LCD driver for LCD chips 175 * 176 * @leds: bitmap representing the LED status 177 */ 178 static void led_LCD_driver(unsigned char leds) 179 { 180 static const unsigned char mask[4] = { 181 LED_HEARTBEAT, LED_DISK_IO, 182 LED_LAN_RCV, LED_LAN_TX }; 183 184 static struct lcd_block * const blockp[4] = { 185 &lcd_info.heartbeat, 186 &lcd_info.disk_io, 187 &lcd_info.lan_rcv, 188 &lcd_info.lan_tx 189 }; 190 static unsigned char latest_leds; 191 int i; 192 193 for (i = 0; i < 4; ++i) { 194 if ((leds & mask[i]) == (latest_leds & mask[i])) 195 continue; 196 197 gsc_writeb( blockp[i]->command, LCD_CMD_REG ); 198 udelay(lcd_info.min_cmd_delay); 199 200 gsc_writeb( leds & mask[i] ? blockp[i]->on : 201 blockp[i]->off, LCD_DATA_REG ); 202 udelay(lcd_info.min_cmd_delay); 203 } 204 latest_leds = leds; 205 206 lcd_print_now(); 207 } 208 209 210 /** 211 * lcd_system_halt() 212 * 213 * @nb: pointer to the notifier_block structure 214 * @event: the event (SYS_RESTART, SYS_HALT or SYS_POWER_OFF) 215 * @buf: pointer to a buffer (not used) 216 * 217 * Called by the reboot notifier chain at shutdown. Stops all 218 * LED/LCD activities. 219 */ 220 static int lcd_system_halt(struct notifier_block *nb, unsigned long event, void *buf) 221 { 222 const char *txt; 223 224 switch (event) { 225 case SYS_RESTART: txt = "SYSTEM RESTART"; 226 break; 227 case SYS_HALT: txt = "SYSTEM HALT"; 228 break; 229 case SYS_POWER_OFF: txt = "SYSTEM POWER OFF"; 230 break; 231 default: return NOTIFY_DONE; 232 } 233 234 lcd_print(txt); 235 236 return NOTIFY_OK; 237 } 238 239 static struct notifier_block lcd_system_halt_notifier = { 240 .notifier_call = lcd_system_halt, 241 }; 242 243 static void set_led(struct led_classdev *led_cdev, enum led_brightness brightness); 244 245 struct hppa_led { 246 struct led_classdev led_cdev; 247 unsigned char led_bit; 248 }; 249 #define to_hppa_led(d) container_of(d, struct hppa_led, led_cdev) 250 251 typedef void (*set_handler)(struct led_classdev *, enum led_brightness); 252 struct led_type { 253 const char *name; 254 set_handler handler; 255 const char *default_trigger; 256 }; 257 258 #define NUM_LEDS_PER_BOARD 8 259 struct hppa_drvdata { 260 struct hppa_led leds[NUM_LEDS_PER_BOARD]; 261 }; 262 263 static void set_led(struct led_classdev *led_cdev, enum led_brightness brightness) 264 { 265 struct hppa_led *p = to_hppa_led(led_cdev); 266 unsigned char led_bit = p->led_bit; 267 268 if (brightness == LED_OFF) 269 lastleds &= ~led_bit; 270 else 271 lastleds |= led_bit; 272 273 if (led_func_ptr) 274 led_func_ptr(lastleds); 275 } 276 277 278 static int hppa_led_generic_probe(struct platform_device *pdev, 279 struct led_type *types) 280 { 281 struct hppa_drvdata *p; 282 int i, err; 283 284 p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL); 285 if (!p) 286 return -ENOMEM; 287 288 for (i = 0; i < NUM_LEDS_PER_BOARD; i++) { 289 struct led_classdev *lp = &p->leds[i].led_cdev; 290 291 p->leds[i].led_bit = BIT(i); 292 lp->name = types[i].name; 293 lp->brightness = LED_FULL; 294 lp->brightness_set = types[i].handler; 295 lp->default_trigger = types[i].default_trigger; 296 err = led_classdev_register(&pdev->dev, lp); 297 if (err) { 298 dev_err(&pdev->dev, "Could not register %s LED\n", 299 lp->name); 300 for (i--; i >= 0; i--) 301 led_classdev_unregister(&p->leds[i].led_cdev); 302 return err; 303 } 304 } 305 306 platform_set_drvdata(pdev, p); 307 308 return 0; 309 } 310 311 static void platform_led_remove(struct platform_device *pdev) 312 { 313 struct hppa_drvdata *p = platform_get_drvdata(pdev); 314 int i; 315 316 for (i = 0; i < NUM_LEDS_PER_BOARD; i++) 317 led_classdev_unregister(&p->leds[i].led_cdev); 318 } 319 320 static struct led_type mainboard_led_types[NUM_LEDS_PER_BOARD] = { 321 { 322 .name = "platform-lan-tx", 323 .handler = set_led, 324 .default_trigger = "tx", 325 }, 326 { 327 .name = "platform-lan-rx", 328 .handler = set_led, 329 .default_trigger = "rx", 330 }, 331 { 332 .name = "platform-disk", 333 .handler = set_led, 334 .default_trigger = "disk-activity", 335 }, 336 { 337 .name = "platform-heartbeat", 338 .handler = set_led, 339 .default_trigger = "heartbeat", 340 }, 341 { 342 .name = "platform-LED4", 343 .handler = set_led, 344 .default_trigger = "panic", 345 }, 346 { 347 .name = "platform-LED5", 348 .handler = set_led, 349 .default_trigger = "panic", 350 }, 351 { 352 .name = "platform-LED6", 353 .handler = set_led, 354 .default_trigger = "panic", 355 }, 356 { 357 .name = "platform-LED7", 358 .handler = set_led, 359 .default_trigger = "panic", 360 }, 361 }; 362 363 static int platform_led_probe(struct platform_device *pdev) 364 { 365 return hppa_led_generic_probe(pdev, mainboard_led_types); 366 } 367 368 MODULE_ALIAS("platform:platform-leds"); 369 370 static struct platform_driver hppa_mainboard_led_driver = { 371 .probe = platform_led_probe, 372 .remove_new = platform_led_remove, 373 .driver = { 374 .name = "platform-leds", 375 }, 376 }; 377 378 static struct platform_driver * const drivers[] = { 379 &hppa_mainboard_led_driver, 380 }; 381 382 static struct platform_device platform_leds = { 383 .name = "platform-leds", 384 }; 385 386 /** 387 * register_led_driver() 388 * 389 * @model: model type, one of the DISPLAY_MODEL_XXXX values 390 * @cmd_reg: physical address of cmd register for the LED/LCD 391 * @data_reg: physical address of data register for the LED/LCD 392 * 393 * Registers a chassis LED or LCD which should be driven by this driver. 394 * Only PDC-based, LASI- or ASP-style LEDs and LCDs are supported. 395 */ 396 int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg) 397 { 398 if (led_func_ptr || !data_reg) 399 return 1; 400 401 /* No LEDs when running in QEMU */ 402 if (running_on_qemu) 403 return 1; 404 405 lcd_info.model = model; /* store the values */ 406 LCD_CMD_REG = (cmd_reg == LED_CMD_REG_NONE) ? 0 : cmd_reg; 407 408 switch (lcd_info.model) { 409 case DISPLAY_MODEL_LCD: 410 LCD_DATA_REG = data_reg; 411 pr_info("led: LCD display at %#lx and %#lx\n", 412 LCD_CMD_REG , LCD_DATA_REG); 413 led_func_ptr = led_LCD_driver; 414 if (lcd_no_led_support) 415 led_type = LED_HAS_LCD; 416 else 417 led_type = LED_HAS_LCD | LED_HAS_LED; 418 break; 419 420 case DISPLAY_MODEL_LASI: 421 LED_DATA_REG = data_reg; 422 led_func_ptr = led_LASI_driver; 423 pr_info("led: LED display at %#lx\n", LED_DATA_REG); 424 led_type = LED_HAS_LED; 425 break; 426 427 case DISPLAY_MODEL_OLD_ASP: 428 LED_DATA_REG = data_reg; 429 led_func_ptr = led_ASP_driver; 430 pr_info("led: LED (ASP-style) display at %#lx\n", 431 LED_DATA_REG); 432 led_type = LED_HAS_LED; 433 break; 434 435 default: 436 pr_err("led: Unknown LCD/LED model type %d\n", lcd_info.model); 437 return 1; 438 } 439 440 platform_register_drivers(drivers, ARRAY_SIZE(drivers)); 441 442 return register_reboot_notifier(&lcd_system_halt_notifier); 443 } 444 445 /** 446 * early_led_init() 447 * 448 * early_led_init() is called early in the bootup-process and asks the 449 * PDC for an usable chassis LCD or LED. If the PDC doesn't return any 450 * info, then a LED might be detected by the LASI or ASP drivers later. 451 * KittyHawk machines have often a buggy PDC, so that we explicitly check 452 * for those machines here. 453 */ 454 static int __init early_led_init(void) 455 { 456 struct pdc_chassis_info chassis_info; 457 int ret; 458 459 snprintf(lcd_text_default, sizeof(lcd_text_default), 460 "Linux %s", init_utsname()->release); 461 strcpy(lcd_text, lcd_text_default); 462 lcd_new_text = 1; 463 464 /* Work around the buggy PDC of KittyHawk-machines */ 465 switch (CPU_HVERSION) { 466 case 0x580: /* KittyHawk DC2-100 (K100) */ 467 case 0x581: /* KittyHawk DC3-120 (K210) */ 468 case 0x582: /* KittyHawk DC3 100 (K400) */ 469 case 0x583: /* KittyHawk DC3 120 (K410) */ 470 case 0x58B: /* KittyHawk DC2 100 (K200) */ 471 pr_info("LCD on KittyHawk-Machine found.\n"); 472 lcd_info.model = DISPLAY_MODEL_LCD; 473 /* KittyHawk has no LED support on its LCD, so skip LED detection */ 474 lcd_no_led_support = 1; 475 goto found; /* use the preinitialized values of lcd_info */ 476 } 477 478 /* initialize the struct, so that we can check for valid return values */ 479 chassis_info.actcnt = chassis_info.maxcnt = 0; 480 481 ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info)); 482 if (ret != PDC_OK) { 483 not_found: 484 lcd_info.model = DISPLAY_MODEL_NONE; 485 return 1; 486 } 487 488 /* check the results. Some machines have a buggy PDC */ 489 if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt) 490 goto not_found; 491 492 switch (lcd_info.model) { 493 case DISPLAY_MODEL_LCD: /* LCD display */ 494 if (chassis_info.actcnt < 495 offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1) 496 goto not_found; 497 if (!lcd_info.act_enable) { 498 /* PDC tells LCD should not be used. */ 499 goto not_found; 500 } 501 break; 502 503 case DISPLAY_MODEL_NONE: /* no LED or LCD available */ 504 goto not_found; 505 506 case DISPLAY_MODEL_LASI: /* Lasi style 8 bit LED display */ 507 if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32) 508 goto not_found; 509 break; 510 511 default: 512 pr_warn("PDC reported unknown LCD/LED model %d\n", 513 lcd_info.model); 514 goto not_found; 515 } 516 517 found: 518 /* register the LCD/LED driver */ 519 return register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG); 520 } 521 arch_initcall(early_led_init); 522 523 /** 524 * register_led_regions() 525 * 526 * Register_led_regions() registers the LCD/LED regions for /procfs. 527 * At bootup - where the initialisation of the LCD/LED often happens 528 * not all internal structures of request_region() are properly set up, 529 * so that we delay the led-registration until after busdevices_init() 530 * has been executed. 531 */ 532 static void __init register_led_regions(void) 533 { 534 switch (lcd_info.model) { 535 case DISPLAY_MODEL_LCD: 536 request_mem_region((unsigned long)LCD_CMD_REG, 1, "lcd_cmd"); 537 request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data"); 538 break; 539 case DISPLAY_MODEL_LASI: 540 case DISPLAY_MODEL_OLD_ASP: 541 request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data"); 542 break; 543 } 544 } 545 546 static int __init startup_leds(void) 547 { 548 if (platform_device_register(&platform_leds)) 549 printk(KERN_INFO "LED: failed to register LEDs\n"); 550 register_led_regions(); 551 return 0; 552 } 553 device_initcall(startup_leds); 554