// 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 <[email protected]>
* (c) Copyright 2001 Randolph Chung <[email protected]>
* (c) Copyright 2000-2023 Helge Deller <[email protected]>
*
* 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 void 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);
}
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_new = 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);
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