diff options
Diffstat (limited to 'drivers/parisc/led.c')
| -rw-r--r-- | drivers/parisc/led.c | 555 |
1 files changed, 555 insertions, 0 deletions
diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c new file mode 100644 index 0000000000..1f75d24160 --- /dev/null +++ b/drivers/parisc/led.c @@ -0,0 +1,555 @@ +// 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 <hdeller@redhat.com> + * (c) Copyright 2001 Randolph Chung <tausq@debian.org> + * (c) Copyright 2000-2023 Helge Deller <deller@gmx.de> + * + * The control of the LEDs and LCDs on PARISC machines has to be done + * completely in software. + * + * The LEDs can be configured at runtime in /sys/class/leds/ + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/ioport.h> +#include <linux/utsname.h> +#include <linux/capability.h> +#include <linux/delay.h> +#include <linux/reboot.h> +#include <linux/uaccess.h> +#include <linux/leds.h> +#include <linux/platform_device.h> + +#include <asm/io.h> +#include <asm/processor.h> +#include <asm/hardware.h> +#include <asm/param.h> /* HZ */ +#include <asm/led.h> +#include <asm/pdc.h> + +#define LED_HAS_LCD 1 +#define LED_HAS_LED 2 + +static unsigned char led_type; /* bitmask of LED_HAS_XXX */ +static unsigned char lastleds; /* LED state from most recent update */ +static unsigned char lcd_new_text; +static unsigned char lcd_text[20]; +static unsigned char lcd_text_default[20]; +static unsigned char lcd_no_led_support; /* KittyHawk doesn't support LED on its LCD */ + +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) +#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))) = +{ + .model = DISPLAY_MODEL_NONE, + .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 */ + +/* ptr to LCD/LED-specific function */ +static void (*led_func_ptr) (unsigned char); + + +static void lcd_print_now(void) +{ + int i; + char *str = lcd_text; + + if (lcd_info.model != DISPLAY_MODEL_LCD) + return; + + if (!lcd_new_text) + return; + lcd_new_text = 0; + + /* 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++) { + gsc_writeb(*str ? *str++ : ' ', LCD_DATA_REG); + udelay(lcd_info.min_cmd_delay); + } +} + +/** + * lcd_print() + * + * @str: string to show on the LCD. If NULL, print current string again. + * + * Displays the given string on the LCD-Display of newer machines. + */ +void lcd_print(const char *str) +{ + /* copy display string to buffer for procfs */ + if (str) + strscpy(lcd_text, str, sizeof(lcd_text)); + lcd_new_text = 1; + + /* print now if LCD without any LEDs */ + if (led_type == LED_HAS_LCD) + lcd_print_now(); +} + +#define LED_DATA 0x01 /* data to shift (0:on 1:off) */ +#define LED_STROBE 0x02 /* strobe to clock data */ + +/** + * led_ASP_driver() - LED driver for the ASP controller chip + * + * @leds: bitmap representing the LED status + */ +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() - LED driver for the LASI controller chip + * + * @leds: bitmap representing the LED status + */ +static void led_LASI_driver(unsigned char leds) +{ + leds = ~leds; + gsc_writeb( leds, LED_DATA_REG ); +} + +/** + * led_LCD_driver() - LED & LCD driver for LCD chips + * + * @leds: bitmap representing the LED status + */ +static void led_LCD_driver(unsigned char leds) +{ + static const unsigned char mask[4] = { + LED_HEARTBEAT, LED_DISK_IO, + LED_LAN_RCV, LED_LAN_TX }; + + static struct lcd_block * const blockp[4] = { + &lcd_info.heartbeat, + &lcd_info.disk_io, + &lcd_info.lan_rcv, + &lcd_info.lan_tx + }; + static unsigned char latest_leds; + int i; + + for (i = 0; i < 4; ++i) { + if ((leds & mask[i]) == (latest_leds & mask[i])) + continue; + + gsc_writeb( blockp[i]->command, LCD_CMD_REG ); + udelay(lcd_info.min_cmd_delay); + + gsc_writeb( leds & mask[i] ? blockp[i]->on : + blockp[i]->off, LCD_DATA_REG ); + udelay(lcd_info.min_cmd_delay); + } + latest_leds = leds; + + lcd_print_now(); +} + + +/** + * lcd_system_halt() + * + * @nb: pointer to the notifier_block structure + * @event: the event (SYS_RESTART, SYS_HALT or SYS_POWER_OFF) + * @buf: pointer to a buffer (not used) + * + * Called by the reboot notifier chain at shutdown. Stops all + * LED/LCD activities. + */ +static int lcd_system_halt(struct notifier_block *nb, unsigned long event, void *buf) +{ + const char *txt; + + 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; + } + + lcd_print(txt); + + return NOTIFY_OK; +} + +static struct notifier_block lcd_system_halt_notifier = { + .notifier_call = lcd_system_halt, +}; + +static void set_led(struct led_classdev *led_cdev, enum led_brightness brightness); + +struct hppa_led { + struct led_classdev led_cdev; + unsigned char led_bit; +}; +#define to_hppa_led(d) container_of(d, struct hppa_led, led_cdev) + +typedef void (*set_handler)(struct led_classdev *, enum led_brightness); +struct led_type { + const char *name; + set_handler handler; + const char *default_trigger; +}; + +#define NUM_LEDS_PER_BOARD 8 +struct hppa_drvdata { + struct hppa_led leds[NUM_LEDS_PER_BOARD]; +}; + +static void set_led(struct led_classdev *led_cdev, enum led_brightness brightness) +{ + struct hppa_led *p = to_hppa_led(led_cdev); + unsigned char led_bit = p->led_bit; + + if (brightness == LED_OFF) + lastleds &= ~led_bit; + else + lastleds |= led_bit; + + if (led_func_ptr) + led_func_ptr(lastleds); +} + + +static int hppa_led_generic_probe(struct platform_device *pdev, + struct led_type *types) +{ + struct hppa_drvdata *p; + int i, err; + + p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL); + if (!p) + return -ENOMEM; + + for (i = 0; i < NUM_LEDS_PER_BOARD; i++) { + struct led_classdev *lp = &p->leds[i].led_cdev; + + p->leds[i].led_bit = BIT(i); + lp->name = types[i].name; + lp->brightness = LED_FULL; + lp->brightness_set = types[i].handler; + lp->default_trigger = types[i].default_trigger; + err = led_classdev_register(&pdev->dev, lp); + if (err) { + dev_err(&pdev->dev, "Could not register %s LED\n", + lp->name); + for (i--; i >= 0; i--) + led_classdev_unregister(&p->leds[i].led_cdev); + return err; + } + } + + platform_set_drvdata(pdev, p); + + return 0; +} + +static int platform_led_remove(struct platform_device *pdev) +{ + struct hppa_drvdata *p = platform_get_drvdata(pdev); + int i; + + for (i = 0; i < NUM_LEDS_PER_BOARD; i++) + led_classdev_unregister(&p->leds[i].led_cdev); + + return 0; +} + +static struct led_type mainboard_led_types[NUM_LEDS_PER_BOARD] = { + { + .name = "platform-lan-tx", + .handler = set_led, + .default_trigger = "tx", + }, + { + .name = "platform-lan-rx", + .handler = set_led, + .default_trigger = "rx", + }, + { + .name = "platform-disk", + .handler = set_led, + .default_trigger = "disk-activity", + }, + { + .name = "platform-heartbeat", + .handler = set_led, + .default_trigger = "heartbeat", + }, + { + .name = "platform-LED4", + .handler = set_led, + .default_trigger = "panic", + }, + { + .name = "platform-LED5", + .handler = set_led, + .default_trigger = "panic", + }, + { + .name = "platform-LED6", + .handler = set_led, + .default_trigger = "panic", + }, + { + .name = "platform-LED7", + .handler = set_led, + .default_trigger = "panic", + }, +}; + +static int platform_led_probe(struct platform_device *pdev) +{ + return hppa_led_generic_probe(pdev, mainboard_led_types); +} + +MODULE_ALIAS("platform:platform-leds"); + +static struct platform_driver hppa_mainboard_led_driver = { + .probe = platform_led_probe, + .remove = platform_led_remove, + .driver = { + .name = "platform-leds", + }, +}; + +static struct platform_driver * const drivers[] = { + &hppa_mainboard_led_driver, +}; + +static struct platform_device platform_leds = { + .name = "platform-leds", +}; + +/** + * register_led_driver() + * + * @model: model type, one of the DISPLAY_MODEL_XXXX values + * @cmd_reg: physical address of cmd register for the LED/LCD + * @data_reg: physical address of data register for the LED/LCD + * + * Registers a chassis LED or LCD which should be driven by this driver. + * Only PDC-based, LASI- or ASP-style LEDs and LCDs are supported. + */ +int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg) +{ + if (led_func_ptr || !data_reg) + return 1; + + /* No LEDs when running in QEMU */ + if (running_on_qemu) + 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; + pr_info("led: LCD display at %#lx and %#lx\n", + LCD_CMD_REG , LCD_DATA_REG); + led_func_ptr = led_LCD_driver; + if (lcd_no_led_support) + led_type = LED_HAS_LCD; + else + led_type = LED_HAS_LCD | LED_HAS_LED; + break; + + case DISPLAY_MODEL_LASI: + LED_DATA_REG = data_reg; + led_func_ptr = led_LASI_driver; + pr_info("led: LED display at %#lx\n", LED_DATA_REG); + led_type = LED_HAS_LED; + break; + + case DISPLAY_MODEL_OLD_ASP: + LED_DATA_REG = data_reg; + led_func_ptr = led_ASP_driver; + pr_info("led: LED (ASP-style) display at %#lx\n", + LED_DATA_REG); + led_type = LED_HAS_LED; + break; + + default: + pr_err("led: Unknown LCD/LED model type %d\n", lcd_info.model); + return 1; + } + + platform_register_drivers(drivers, ARRAY_SIZE(drivers)); + + return register_reboot_notifier(&lcd_system_halt_notifier); +} + +/** + * early_led_init() + * + * early_led_init() is called early in the bootup-process and asks the + * PDC for an usable chassis LCD or LED. If the PDC doesn't return any + * info, then a LED might be detected by the LASI or ASP drivers later. + * KittyHawk machines have often a buggy PDC, so that we explicitly check + * for those machines here. + */ +static int __init early_led_init(void) +{ + struct pdc_chassis_info chassis_info; + int ret; + + snprintf(lcd_text_default, sizeof(lcd_text_default), + "Linux %s", init_utsname()->release); + strcpy(lcd_text, lcd_text_default); + lcd_new_text = 1; + + /* 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) */ + pr_info("LCD on KittyHawk-Machine found.\n"); + lcd_info.model = DISPLAY_MODEL_LCD; + /* KittyHawk has no LED support on its LCD, so skip LED detection */ + 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 */ + chassis_info.actcnt = chassis_info.maxcnt = 0; + + ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info)); + if (ret != PDC_OK) { +not_found: + lcd_info.model = DISPLAY_MODEL_NONE; + return 1; + } + + /* 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) { + /* PDC tells LCD should not be used. */ + goto not_found; + } + break; + + case DISPLAY_MODEL_NONE: /* no LED or LCD available */ + 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: + pr_warn("PDC reported unknown LCD/LED model %d\n", + lcd_info.model); + goto not_found; + } + +found: + /* register the LCD/LED driver */ + return register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG); +} +arch_initcall(early_led_init); + +/** + * register_led_regions() + * + * Register_led_regions() registers the LCD/LED regions for /procfs. + * At bootup - where the initialisation of the LCD/LED often 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. + */ +static 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; + } +} + +static int __init startup_leds(void) +{ + if (platform_device_register(&platform_leds)) + printk(KERN_INFO "LED: failed to register LEDs\n"); + register_led_regions(); + return 0; +} +device_initcall(startup_leds); |