drivers/watchdog/lenovo_se10_wdt.c - linux - Git at Google

 // 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<dober@lenovo.com>");
 MODULE_AUTHOR("Mark Pearson <mpearson-lenovo@squebb.ca>");
 MODULE_DESCRIPTION("WDT driver for Lenovo SE10");
	// 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<dober@lenovo.com>");
	MODULE_AUTHOR("Mark Pearson <mpearson-lenovo@squebb.ca>");
	MODULE_DESCRIPTION("WDT driver for Lenovo SE10");