// SPDX-License-Identifier: GPL-2.0-or-later
/*
* WDT driver for Lenovo SE10.
*/
#include <linux/delay.h>
#include <linux/dmi.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#define STATUS_PORT 0x6C
#define CMD_PORT 0x6C
#define DATA_PORT 0x68
#define OUTBUF_FULL 0x01
#define INBUF_EMPTY 0x02
#define CFG_LDN 0x07
#define CFG_BRAM_LDN 0x10 /* for BRAM Base */
#define CFG_PORT 0x2E
#define CFG_SIZE 2
#define CMD_SIZE 4
#define BRAM_SIZE 2
#define UNLOCK_KEY 0x87
#define LOCK_KEY 0xAA
#define CUS_WDT_SWI 0x1A
#define CUS_WDT_CFG 0x1B
#define CUS_WDT_FEED 0xB0
#define CUS_WDT_CNT 0xB1
#define DRVNAME "lenovo-se10-wdt"
/*The timeout range is 1-255 seconds*/
#define MIN_TIMEOUT 1
#define MAX_TIMEOUT 255
#define MAX_WAIT 10
#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
static unsigned short bram_base;
static struct platform_device *se10_pdev;
static int timeout; /* in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
"Watchdog timeout in seconds. 1 <= timeout <= 255, default="
__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
struct se10_wdt {
struct watchdog_device wdd;
};
static int set_bram(unsigned char offset, unsigned char val)
{
if (!request_muxed_region(bram_base, BRAM_SIZE, DRVNAME))
return -EBUSY;
outb(offset, bram_base);
outb(val, bram_base + 1);
release_region(bram_base, BRAM_SIZE);
return 0;
}
static void wait_for_buffer(int condition)
{
int loop = 0;
while (1) {
if (inb(STATUS_PORT) & condition || loop > MAX_WAIT)
break;
loop++;
usleep_range(10, 125);
}
}
static void send_cmd(unsigned char cmd)
{
wait_for_buffer(INBUF_EMPTY);
outb(cmd, CMD_PORT);
wait_for_buffer(INBUF_EMPTY);
}
static void lpc_write(unsigned char index, unsigned char data)
{
outb(index, CFG_PORT);
outb(data, CFG_PORT + 1);
}
static unsigned char lpc_read(unsigned char index)
{
outb(index, CFG_PORT);
return inb(CFG_PORT + 1);
}
static int wdt_start(struct watchdog_device *wdog)
{
return set_bram(CUS_WDT_SWI, 0x80);
}
static int wdt_set_timeout(struct watchdog_device *wdog, unsigned int timeout)
{
wdog->timeout = timeout;
return set_bram(CUS_WDT_CFG, wdog->timeout);
}
static int wdt_stop(struct watchdog_device *wdog)
{
return set_bram(CUS_WDT_SWI, 0);
}
static unsigned int wdt_get_time(struct watchdog_device *wdog)
{
unsigned char time;
if (!request_muxed_region(CMD_PORT, CMD_SIZE, DRVNAME))
return -EBUSY;
send_cmd(CUS_WDT_CNT);
wait_for_buffer(OUTBUF_FULL);
time = inb(DATA_PORT);
release_region(CMD_PORT, CMD_SIZE);
return time;
}
static int wdt_ping(struct watchdog_device *wdog)
{
if (!request_muxed_region(CMD_PORT, CMD_SIZE, DRVNAME))
return -EBUSY;
send_cmd(CUS_WDT_FEED);
release_region(CMD_PORT, CMD_SIZE);
return 0;
}
static const struct watchdog_info wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "Lenovo SE10 Watchdog",
};
static const struct watchdog_ops se10_wdt_ops = {
.owner = THIS_MODULE,
.start = wdt_start,
.stop = wdt_stop,
.ping = wdt_ping,
.set_timeout = wdt_set_timeout,
.get_timeleft = wdt_get_time,
};
static unsigned int get_chipID(void)
{
unsigned char msb, lsb;
outb(UNLOCK_KEY, CFG_PORT);
outb(0x01, CFG_PORT);
outb(0x55, CFG_PORT);
outb(0x55, CFG_PORT);
msb = lpc_read(0x20);
lsb = lpc_read(0x21);
outb(LOCK_KEY, CFG_PORT);
return (msb * 256 + lsb);
}
static int se10_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct se10_wdt *priv;
unsigned int chip_id;
int ret;
if (!request_muxed_region(CFG_PORT, CFG_SIZE, DRVNAME))
return -EBUSY;
chip_id = get_chipID();
if (chip_id != 0x5632) {
release_region(CFG_PORT, CFG_SIZE);
return -ENODEV;
}
lpc_write(CFG_LDN, CFG_BRAM_LDN);
bram_base = (lpc_read(0x60) << 8) | lpc_read(0x61);
release_region(CFG_PORT, CFG_SIZE);
dev_info(dev, "Found Lenovo SE10 0x%x\n", chip_id);
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
watchdog_set_drvdata(&priv->wdd, priv);
priv->wdd.parent = dev;
priv->wdd.info = &wdt_info;
priv->wdd.ops = &se10_wdt_ops;
priv->wdd.timeout = WATCHDOG_TIMEOUT; /* Set default timeout */
priv->wdd.min_timeout = MIN_TIMEOUT;
priv->wdd.max_timeout = MAX_TIMEOUT;
set_bram(CUS_WDT_CFG, WATCHDOG_TIMEOUT); /* Set time to default */
watchdog_init_timeout(&priv->wdd, timeout, dev);
watchdog_set_nowayout(&priv->wdd, nowayout);
watchdog_stop_on_reboot(&priv->wdd);
watchdog_stop_on_unregister(&priv->wdd);
ret = devm_watchdog_register_device(dev, &priv->wdd);
dev_dbg(&pdev->dev, "initialized. timeout=%d sec (nowayout=%d)\n",
priv->wdd.timeout, nowayout);
return ret;
}
static struct platform_driver se10_wdt_driver = {
.driver = {
.name = DRVNAME,
},
.probe = se10_wdt_probe,
};
static int se10_create_platform_device(const struct dmi_system_id *id)
{
int err;
se10_pdev = platform_device_alloc("lenovo-se10-wdt", -1);
if (!se10_pdev)
return -ENOMEM;
err = platform_device_add(se10_pdev);
if (err)
platform_device_put(se10_pdev);
return err;
}
static const struct dmi_system_id se10_dmi_table[] __initconst = {
{
.ident = "LENOVO-SE10",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_NAME, "12NH"),
},
.callback = se10_create_platform_device,
},
{
.ident = "LENOVO-SE10",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_NAME, "12NJ"),
},
.callback = se10_create_platform_device,
},
{
.ident = "LENOVO-SE10",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_NAME, "12NK"),
},
.callback = se10_create_platform_device,
},
{
.ident = "LENOVO-SE10",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_NAME, "12NL"),
},
.callback = se10_create_platform_device,
},
{
.ident = "LENOVO-SE10",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_NAME, "12NM"),
},
.callback = se10_create_platform_device,
},
{}
};
MODULE_DEVICE_TABLE(dmi, se10_dmi_table);
static int __init se10_wdt_init(void)
{
if (!dmi_check_system(se10_dmi_table))
return -ENODEV;
return platform_driver_register(&se10_wdt_driver);
}
static void __exit se10_wdt_exit(void)
{
if (se10_pdev)
platform_device_unregister(se10_pdev);
platform_driver_unregister(&se10_wdt_driver);
}
module_init(se10_wdt_init);
module_exit(se10_wdt_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Ober<[email protected]>");
MODULE_AUTHOR("Mark Pearson <[email protected]>");
MODULE_DESCRIPTION("WDT driver for Lenovo SE10");
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