// SPDX-License-Identifier: GPL-2.0-or-later /* * Chassis LCD/LED driver for HP-PARISC workstations * * (c) Copyright 2000 Red Hat Software * (c) Copyright 2000 Helge Deller * (c) Copyright 2001-2009 Helge Deller * (c) Copyright 2001 Randolph Chung * * TODO: * - speed-up calculations with inlined assembler * - interface to write to second row of LCD from /proc (if technically possible) * * Changes: * - Audit copy_from_user in led_proc_write. * Daniele Bellucci * - Switch from using a tasklet to a work queue, so the led_LCD_driver * can sleep. * David Pye */ #include #include /* for offsetof() */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* HZ */ #include #include #include /* The control of the LEDs and LCDs on PARISC-machines have to be done completely in software. The necessary calculations are done in a work queue task which is scheduled regularly, and since the calculations may consume a relatively large amount of CPU time, some of the calculations can be turned off with the following variables (controlled via procfs) */ static int led_type __read_mostly = -1; static unsigned char lastleds; /* LED state from most recent update */ static unsigned int led_heartbeat __read_mostly = 1; static unsigned int led_diskio __read_mostly; static unsigned int led_lanrxtx __read_mostly; static char lcd_text[32] __read_mostly; static char lcd_text_default[32] __read_mostly; static int lcd_no_led_support __read_mostly = 0; /* KittyHawk doesn't support LED on its LCD */ static struct workqueue_struct *led_wq; static void led_work_func(struct work_struct *); static DECLARE_DELAYED_WORK(led_task, led_work_func); #if 0 #define DPRINTK(x) printk x #else #define DPRINTK(x) #endif struct lcd_block { unsigned char command; /* stores the command byte */ unsigned char on; /* value for turning LED on */ unsigned char off; /* value for turning LED off */ }; /* Structure returned by PDC_RETURN_CHASSIS_INFO */ /* NOTE: we use unsigned long:16 two times, since the following member lcd_cmd_reg_addr needs to be 64bit aligned on 64bit PA2.0-machines */ struct pdc_chassis_lcd_info_ret_block { unsigned long model:16; /* DISPLAY_MODEL_XXXX */ unsigned long lcd_width:16; /* width of the LCD in chars (DISPLAY_MODEL_LCD only) */ unsigned long lcd_cmd_reg_addr; /* ptr to LCD cmd-register & data ptr for LED */ unsigned long lcd_data_reg_addr; /* ptr to LCD data-register (LCD only) */ unsigned int min_cmd_delay; /* delay in uS after cmd-write (LCD only) */ unsigned char reset_cmd1; /* command #1 for writing LCD string (LCD only) */ unsigned char reset_cmd2; /* command #2 for writing LCD string (LCD only) */ unsigned char act_enable; /* 0 = no activity (LCD only) */ struct lcd_block heartbeat; struct lcd_block disk_io; struct lcd_block lan_rcv; struct lcd_block lan_tx; char _pad; }; /* LCD_CMD and LCD_DATA for KittyHawk machines */ #define KITTYHAWK_LCD_CMD F_EXTEND(0xf0190000UL) /* 64bit-ready */ #define KITTYHAWK_LCD_DATA (KITTYHAWK_LCD_CMD+1) /* lcd_info is pre-initialized to the values needed to program KittyHawk LCD's * HP seems to have used Sharp/Hitachi HD44780 LCDs most of the time. */ static struct pdc_chassis_lcd_info_ret_block lcd_info __attribute__((aligned(8))) __read_mostly = { .model = DISPLAY_MODEL_LCD, .lcd_width = 16, .lcd_cmd_reg_addr = KITTYHAWK_LCD_CMD, .lcd_data_reg_addr = KITTYHAWK_LCD_DATA, .min_cmd_delay = 80, .reset_cmd1 = 0x80, .reset_cmd2 = 0xc0, }; /* direct access to some of the lcd_info variables */ #define LCD_CMD_REG lcd_info.lcd_cmd_reg_addr #define LCD_DATA_REG lcd_info.lcd_data_reg_addr #define LED_DATA_REG lcd_info.lcd_cmd_reg_addr /* LASI & ASP only */ #define LED_HASLCD 1 #define LED_NOLCD 0 /* The workqueue must be created at init-time */ static int start_task(void) { /* Display the default text now */ if (led_type == LED_HASLCD) lcd_print( lcd_text_default ); /* KittyHawk has no LED support on its LCD */ if (lcd_no_led_support) return 0; /* Create the work queue and queue the LED task */ led_wq = create_singlethread_workqueue("led_wq"); if (!led_wq) return -ENOMEM; queue_delayed_work(led_wq, &led_task, 0); return 0; } device_initcall(start_task); /* ptr to LCD/LED-specific function */ static void (*led_func_ptr) (unsigned char) __read_mostly; #ifdef CONFIG_PROC_FS static int led_proc_show(struct seq_file *m, void *v) { switch ((long)m->private) { case LED_NOLCD: seq_printf(m, "Heartbeat: %d\n", led_heartbeat); seq_printf(m, "Disk IO: %d\n", led_diskio); seq_printf(m, "LAN Rx/Tx: %d\n", led_lanrxtx); break; case LED_HASLCD: seq_printf(m, "%s\n", lcd_text); break; default: return 0; } return 0; } static int led_proc_open(struct inode *inode, struct file *file) { return single_open(file, led_proc_show, PDE_DATA(inode)); } static ssize_t led_proc_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) { void *data = PDE_DATA(file_inode(file)); char *cur, lbuf[32]; int d; if (!capable(CAP_SYS_ADMIN)) return -EACCES; if (count >= sizeof(lbuf)) count = sizeof(lbuf)-1; if (copy_from_user(lbuf, buf, count)) return -EFAULT; lbuf[count] = 0; cur = lbuf; switch ((long)data) { case LED_NOLCD: d = *cur++ - '0'; if (d != 0 && d != 1) goto parse_error; led_heartbeat = d; if (*cur++ != ' ') goto parse_error; d = *cur++ - '0'; if (d != 0 && d != 1) goto parse_error; led_diskio = d; if (*cur++ != ' ') goto parse_error; d = *cur++ - '0'; if (d != 0 && d != 1) goto parse_error; led_lanrxtx = d; break; case LED_HASLCD: if (*cur && cur[strlen(cur)-1] == '\n') cur[strlen(cur)-1] = 0; if (*cur == 0) cur = lcd_text_default; lcd_print(cur); break; default: return 0; } return count; parse_error: if ((long)data == LED_NOLCD) printk(KERN_CRIT "Parse error: expect \"n n n\" (n == 0 or 1) for heartbeat,\ndisk io and lan tx/rx indicators\n"); return -EINVAL; } static const struct proc_ops led_proc_ops = { .proc_open = led_proc_open, .proc_read = seq_read, .proc_lseek = seq_lseek, .proc_release = single_release, .proc_write = led_proc_write, }; static int __init led_create_procfs(void) { struct proc_dir_entry *proc_pdc_root = NULL; struct proc_dir_entry *ent; if (led_type == -1) return -1; proc_pdc_root = proc_mkdir("pdc", NULL); if (!proc_pdc_root) return -1; if (!lcd_no_led_support) { ent = proc_create_data("led", 0644, proc_pdc_root, &led_proc_ops, (void *)LED_NOLCD); /* LED */ if (!ent) return -1; } if (led_type == LED_HASLCD) { ent = proc_create_data("lcd", 0644, proc_pdc_root, &led_proc_ops, (void *)LED_HASLCD); /* LCD */ if (!ent) return -1; } return 0; } #endif /* ** ** led_ASP_driver() ** */ #define LED_DATA 0x01 /* data to shift (0:on 1:off) */ #define LED_STROBE 0x02 /* strobe to clock data */ static void led_ASP_driver(unsigned char leds) { int i; leds = ~leds; for (i = 0; i < 8; i++) { unsigned char value; value = (leds & 0x80) >> 7; gsc_writeb( value, LED_DATA_REG ); gsc_writeb( value | LED_STROBE, LED_DATA_REG ); leds <<= 1; } } /* ** ** led_LASI_driver() ** */ static void led_LASI_driver(unsigned char leds) { leds = ~leds; gsc_writeb( leds, LED_DATA_REG ); } /* ** ** led_LCD_driver() ** */ static void led_LCD_driver(unsigned char leds) { static int i; static unsigned char mask[4] = { LED_HEARTBEAT, LED_DISK_IO, LED_LAN_RCV, LED_LAN_TX }; static struct lcd_block * blockp[4] = { &lcd_info.heartbeat, &lcd_info.disk_io, &lcd_info.lan_rcv, &lcd_info.lan_tx }; /* Convert min_cmd_delay to milliseconds */ unsigned int msec_cmd_delay = 1 + (lcd_info.min_cmd_delay / 1000); for (i=0; i<4; ++i) { if ((leds & mask[i]) != (lastleds & mask[i])) { gsc_writeb( blockp[i]->command, LCD_CMD_REG ); msleep(msec_cmd_delay); gsc_writeb( leds & mask[i] ? blockp[i]->on : blockp[i]->off, LCD_DATA_REG ); msleep(msec_cmd_delay); } } } /* ** ** led_get_net_activity() ** ** calculate if there was TX- or RX-throughput on the network interfaces ** (analog to dev_get_info() from net/core/dev.c) ** */ static __inline__ int led_get_net_activity(void) { #ifndef CONFIG_NET return 0; #else static u64 rx_total_last, tx_total_last; u64 rx_total, tx_total; struct net_device *dev; int retval; rx_total = tx_total = 0; /* we are running as a workqueue task, so we can use an RCU lookup */ rcu_read_lock(); for_each_netdev_rcu(&init_net, dev) { const struct rtnl_link_stats64 *stats; struct rtnl_link_stats64 temp; struct in_device *in_dev = __in_dev_get_rcu(dev); if (!in_dev || !in_dev->ifa_list) continue; if (ipv4_is_loopback(in_dev->ifa_list->ifa_local)) continue; stats = dev_get_stats(dev, &temp); rx_total += stats->rx_packets; tx_total += stats->tx_packets; } rcu_read_unlock(); retval = 0; if (rx_total != rx_total_last) { rx_total_last = rx_total; retval |= LED_LAN_RCV; } if (tx_total != tx_total_last) { tx_total_last = tx_total; retval |= LED_LAN_TX; } return retval; #endif } /* ** ** led_get_diskio_activity() ** ** calculate if there was disk-io in the system ** */ static __inline__ int led_get_diskio_activity(void) { static unsigned long last_pgpgin, last_pgpgout; unsigned long events[NR_VM_EVENT_ITEMS]; int changed; all_vm_events(events); /* Just use a very simple calculation here. Do not care about overflow, since we only want to know if there was activity or not. */ changed = (events[PGPGIN] != last_pgpgin) || (events[PGPGOUT] != last_pgpgout); last_pgpgin = events[PGPGIN]; last_pgpgout = events[PGPGOUT]; return (changed ? LED_DISK_IO : 0); } /* ** led_work_func() ** ** manages when and which chassis LCD/LED gets updated TODO: - display load average (older machines like 715/64 have 4 "free" LED's for that) - optimizations */ #define HEARTBEAT_LEN (HZ*10/100) #define HEARTBEAT_2ND_RANGE_START (HZ*28/100) #define HEARTBEAT_2ND_RANGE_END (HEARTBEAT_2ND_RANGE_START + HEARTBEAT_LEN) #define LED_UPDATE_INTERVAL (1 + (HZ*19/1000)) static void led_work_func (struct work_struct *unused) { static unsigned long last_jiffies; static unsigned long count_HZ; /* counter in range 0..HZ */ unsigned char currentleds = 0; /* stores current value of the LEDs */ /* exit if not initialized */ if (!led_func_ptr) return; /* increment the heartbeat timekeeper */ count_HZ += jiffies - last_jiffies; last_jiffies = jiffies; if (count_HZ >= HZ) count_HZ = 0; if (likely(led_heartbeat)) { /* flash heartbeat-LED like a real heart * (2 x short then a long delay) */ if (count_HZ < HEARTBEAT_LEN || (count_HZ >= HEARTBEAT_2ND_RANGE_START && count_HZ < HEARTBEAT_2ND_RANGE_END)) currentleds |= LED_HEARTBEAT; } if (likely(led_lanrxtx)) currentleds |= led_get_net_activity(); if (likely(led_diskio)) currentleds |= led_get_diskio_activity(); /* blink LEDs if we got an Oops (HPMC) */ if (unlikely(oops_in_progress)) { if (boot_cpu_data.cpu_type >= pcxl2) { /* newer machines don't have loadavg. LEDs, so we * let all LEDs blink twice per second instead */ currentleds = (count_HZ <= (HZ/2)) ? 0 : 0xff; } else { /* old machines: blink loadavg. LEDs twice per second */ if (count_HZ <= (HZ/2)) currentleds &= ~(LED4|LED5|LED6|LED7); else currentleds |= (LED4|LED5|LED6|LED7); } } if (currentleds != lastleds) { led_func_ptr(currentleds); /* Update the LCD/LEDs */ lastleds = currentleds; } queue_delayed_work(led_wq, &led_task, LED_UPDATE_INTERVAL); } /* ** led_halt() ** ** called by the reboot notifier chain at shutdown and stops all ** LED/LCD activities. ** */ static int led_halt(struct notifier_block *, unsigned long, void *); static struct notifier_block led_notifier = { .notifier_call = led_halt, }; static int notifier_disabled = 0; static int led_halt(struct notifier_block *nb, unsigned long event, void *buf) { char *txt; if (notifier_disabled) return NOTIFY_OK; notifier_disabled = 1; switch (event) { case SYS_RESTART: txt = "SYSTEM RESTART"; break; case SYS_HALT: txt = "SYSTEM HALT"; break; case SYS_POWER_OFF: txt = "SYSTEM POWER OFF"; break; default: return NOTIFY_DONE; } /* Cancel the work item and delete the queue */ if (led_wq) { cancel_delayed_work_sync(&led_task); destroy_workqueue(led_wq); led_wq = NULL; } if (lcd_info.model == DISPLAY_MODEL_LCD) lcd_print(txt); else if (led_func_ptr) led_func_ptr(0xff); /* turn all LEDs ON */ return NOTIFY_OK; } /* ** register_led_driver() ** ** registers an external LED or LCD for usage by this driver. ** currently only LCD-, LASI- and ASP-style LCD/LED's are supported. ** */ int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg) { static int initialized; if (initialized || !data_reg) return 1; lcd_info.model = model; /* store the values */ LCD_CMD_REG = (cmd_reg == LED_CMD_REG_NONE) ? 0 : cmd_reg; switch (lcd_info.model) { case DISPLAY_MODEL_LCD: LCD_DATA_REG = data_reg; printk(KERN_INFO "LCD display at %lx,%lx registered\n", LCD_CMD_REG , LCD_DATA_REG); led_func_ptr = led_LCD_driver; led_type = LED_HASLCD; break; case DISPLAY_MODEL_LASI: /* Skip to register LED in QEMU */ if (running_on_qemu) return 1; LED_DATA_REG = data_reg; led_func_ptr = led_LASI_driver; printk(KERN_INFO "LED display at %lx registered\n", LED_DATA_REG); led_type = LED_NOLCD; break; case DISPLAY_MODEL_OLD_ASP: LED_DATA_REG = data_reg; led_func_ptr = led_ASP_driver; printk(KERN_INFO "LED (ASP-style) display at %lx registered\n", LED_DATA_REG); led_type = LED_NOLCD; break; default: printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n", __func__, lcd_info.model); return 1; } /* mark the LCD/LED driver now as initialized and * register to the reboot notifier chain */ initialized++; register_reboot_notifier(&led_notifier); /* Ensure the work is queued */ if (led_wq) { queue_delayed_work(led_wq, &led_task, 0); } return 0; } /* ** register_led_regions() ** ** register_led_regions() registers the LCD/LED regions for /procfs. ** At bootup - where the initialisation of the LCD/LED normally happens - ** not all internal structures of request_region() are properly set up, ** so that we delay the led-registration until after busdevices_init() ** has been executed. ** */ void __init register_led_regions(void) { switch (lcd_info.model) { case DISPLAY_MODEL_LCD: request_mem_region((unsigned long)LCD_CMD_REG, 1, "lcd_cmd"); request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data"); break; case DISPLAY_MODEL_LASI: case DISPLAY_MODEL_OLD_ASP: request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data"); break; } } /* ** ** lcd_print() ** ** Displays the given string on the LCD-Display of newer machines. ** lcd_print() disables/enables the timer-based led work queue to ** avoid a race condition while writing the CMD/DATA register pair. ** */ int lcd_print( const char *str ) { int i; if (!led_func_ptr || lcd_info.model != DISPLAY_MODEL_LCD) return 0; /* temporarily disable the led work task */ if (led_wq) cancel_delayed_work_sync(&led_task); /* copy display string to buffer for procfs */ strlcpy(lcd_text, str, sizeof(lcd_text)); /* Set LCD Cursor to 1st character */ gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG); udelay(lcd_info.min_cmd_delay); /* Print the string */ for (i=0; i < lcd_info.lcd_width; i++) { if (str && *str) gsc_writeb(*str++, LCD_DATA_REG); else gsc_writeb(' ', LCD_DATA_REG); udelay(lcd_info.min_cmd_delay); } /* re-queue the work */ if (led_wq) { queue_delayed_work(led_wq, &led_task, 0); } return lcd_info.lcd_width; } /* ** led_init() ** ** led_init() is called very early in the bootup-process from setup.c ** and asks the PDC for an usable chassis LCD or LED. ** If the PDC doesn't return any info, then the LED ** is detected by lasi.c or asp.c and registered with the ** above functions lasi_led_init() or asp_led_init(). ** KittyHawk machines have often a buggy PDC, so that ** we explicitly check for those machines here. */ int __init led_init(void) { struct pdc_chassis_info chassis_info; int ret; snprintf(lcd_text_default, sizeof(lcd_text_default), "Linux %s", init_utsname()->release); /* Work around the buggy PDC of KittyHawk-machines */ switch (CPU_HVERSION) { case 0x580: /* KittyHawk DC2-100 (K100) */ case 0x581: /* KittyHawk DC3-120 (K210) */ case 0x582: /* KittyHawk DC3 100 (K400) */ case 0x583: /* KittyHawk DC3 120 (K410) */ case 0x58B: /* KittyHawk DC2 100 (K200) */ printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, " "LED detection skipped.\n", __FILE__, CPU_HVERSION); lcd_no_led_support = 1; goto found; /* use the preinitialized values of lcd_info */ } /* initialize the struct, so that we can check for valid return values */ lcd_info.model = DISPLAY_MODEL_NONE; chassis_info.actcnt = chassis_info.maxcnt = 0; ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info)); if (ret == PDC_OK) { DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), " "lcd_width=%d, cmd_delay=%u,\n" "%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n", __FILE__, lcd_info.model, (lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" : (lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown", lcd_info.lcd_width, lcd_info.min_cmd_delay, __FILE__, sizeof(lcd_info), chassis_info.actcnt, chassis_info.maxcnt)); DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n", __FILE__, lcd_info.lcd_cmd_reg_addr, lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1, lcd_info.reset_cmd2, lcd_info.act_enable )); /* check the results. Some machines have a buggy PDC */ if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt) goto not_found; switch (lcd_info.model) { case DISPLAY_MODEL_LCD: /* LCD display */ if (chassis_info.actcnt < offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1) goto not_found; if (!lcd_info.act_enable) { DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n")); goto not_found; } break; case DISPLAY_MODEL_NONE: /* no LED or LCD available */ printk(KERN_INFO "PDC reported no LCD or LED.\n"); goto not_found; case DISPLAY_MODEL_LASI: /* Lasi style 8 bit LED display */ if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32) goto not_found; break; default: printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n", lcd_info.model); goto not_found; } /* switch() */ found: /* register the LCD/LED driver */ register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG); return 0; } else { /* if() */ DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret)); } not_found: lcd_info.model = DISPLAY_MODEL_NONE; return 1; } static void __exit led_exit(void) { unregister_reboot_notifier(&led_notifier); return; } #ifdef CONFIG_PROC_FS module_init(led_create_procfs) #endif