diff options
Diffstat (limited to 'drivers/hwmon/sch56xx-common.c')
| -rw-r--r-- | drivers/hwmon/sch56xx-common.c | 323 |
1 files changed, 301 insertions, 22 deletions
diff --git a/drivers/hwmon/sch56xx-common.c b/drivers/hwmon/sch56xx-common.c index fac32ee0b10..73868198328 100644 --- a/drivers/hwmon/sch56xx-common.c +++ b/drivers/hwmon/sch56xx-common.c @@ -1,5 +1,5 @@ /*************************************************************************** - * Copyright (C) 2010-2011 Hans de Goede <hdegoede@redhat.com> * + * Copyright (C) 2010-2012 Hans de Goede <hdegoede@redhat.com> * * * * This program is free software; you can redistribute it and/or modify * * it under the terms of the GNU General Public License as published by * @@ -26,8 +26,20 @@ #include <linux/io.h> #include <linux/acpi.h> #include <linux/delay.h> +#include <linux/fs.h> +#include <linux/watchdog.h> +#include <linux/miscdevice.h> +#include <linux/uaccess.h> +#include <linux/kref.h> +#include <linux/slab.h> #include "sch56xx-common.h" +/* Insmod parameters */ +static int nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + #define SIO_SCH56XX_LD_EM 0x0C /* Embedded uController Logical Dev */ #define SIO_UNLOCK_KEY 0x55 /* Key to enable Super-I/O */ #define SIO_LOCK_KEY 0xAA /* Key to disable Super-I/O */ @@ -40,11 +52,29 @@ #define SIO_SCH5627_ID 0xC6 /* Chipset ID */ #define SIO_SCH5636_ID 0xC7 /* Chipset ID */ -#define REGION_LENGTH 9 +#define REGION_LENGTH 10 #define SCH56XX_CMD_READ 0x02 #define SCH56XX_CMD_WRITE 0x03 +/* Watchdog registers */ +#define SCH56XX_REG_WDOG_PRESET 0x58B +#define SCH56XX_REG_WDOG_CONTROL 0x58C +#define SCH56XX_WDOG_TIME_BASE_SEC 0x01 +#define SCH56XX_REG_WDOG_OUTPUT_ENABLE 0x58E +#define SCH56XX_WDOG_OUTPUT_ENABLE 0x02 + +struct sch56xx_watchdog_data { + u16 addr; + struct mutex *io_lock; + struct kref kref; + struct watchdog_info wdinfo; + struct watchdog_device wddev; + u8 watchdog_preset; + u8 watchdog_control; + u8 watchdog_output_enable; +}; + static struct platform_device *sch56xx_pdev; /* Super I/O functions */ @@ -131,8 +161,8 @@ static int sch56xx_send_cmd(u16 addr, u8 cmd, u16 reg, u8 v) break; } if (i == max_busy_polls + max_lazy_polls) { - pr_err("Max retries exceeded reading virtual " - "register 0x%04hx (%d)\n", reg, 1); + pr_err("Max retries exceeded reading virtual register 0x%04hx (%d)\n", + reg, 1); return -EIO; } @@ -148,12 +178,12 @@ static int sch56xx_send_cmd(u16 addr, u8 cmd, u16 reg, u8 v) break; if (i == 0) - pr_warn("EC reports: 0x%02x reading virtual register " - "0x%04hx\n", (unsigned int)val, reg); + pr_warn("EC reports: 0x%02x reading virtual register 0x%04hx\n", + (unsigned int)val, reg); } if (i == max_busy_polls) { - pr_err("Max retries exceeded reading virtual " - "register 0x%04hx (%d)\n", reg, 2); + pr_err("Max retries exceeded reading virtual register 0x%04hx (%d)\n", + reg, 2); return -EIO; } @@ -224,10 +254,259 @@ int sch56xx_read_virtual_reg12(u16 addr, u16 msb_reg, u16 lsn_reg, } EXPORT_SYMBOL(sch56xx_read_virtual_reg12); -static int __init sch56xx_find(int sioaddr, unsigned short *address, - const char **name) +/* + * Watchdog routines + */ + +/* Release our data struct when we're unregistered *and* + all references to our watchdog device are released */ +static void watchdog_release_resources(struct kref *r) +{ + struct sch56xx_watchdog_data *data = + container_of(r, struct sch56xx_watchdog_data, kref); + kfree(data); +} + +static int watchdog_set_timeout(struct watchdog_device *wddev, + unsigned int timeout) +{ + struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev); + unsigned int resolution; + u8 control; + int ret; + + /* 1 second or 60 second resolution? */ + if (timeout <= 255) + resolution = 1; + else + resolution = 60; + + if (timeout < resolution || timeout > (resolution * 255)) + return -EINVAL; + + if (resolution == 1) + control = data->watchdog_control | SCH56XX_WDOG_TIME_BASE_SEC; + else + control = data->watchdog_control & ~SCH56XX_WDOG_TIME_BASE_SEC; + + if (data->watchdog_control != control) { + mutex_lock(data->io_lock); + ret = sch56xx_write_virtual_reg(data->addr, + SCH56XX_REG_WDOG_CONTROL, + control); + mutex_unlock(data->io_lock); + if (ret) + return ret; + + data->watchdog_control = control; + } + + /* + * Remember new timeout value, but do not write as that (re)starts + * the watchdog countdown. + */ + data->watchdog_preset = DIV_ROUND_UP(timeout, resolution); + wddev->timeout = data->watchdog_preset * resolution; + + return 0; +} + +static int watchdog_start(struct watchdog_device *wddev) +{ + struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev); + int ret; + u8 val; + + /* + * The sch56xx's watchdog cannot really be started / stopped + * it is always running, but we can avoid the timer expiring + * from causing a system reset by clearing the output enable bit. + * + * The sch56xx's watchdog will set the watchdog event bit, bit 0 + * of the second interrupt source register (at base-address + 9), + * when the timer expires. + * + * This will only cause a system reset if the 0-1 flank happens when + * output enable is true. Setting output enable after the flank will + * not cause a reset, nor will the timer expiring a second time. + * This means we must clear the watchdog event bit in case it is set. + * + * The timer may still be running (after a recent watchdog_stop) and + * mere milliseconds away from expiring, so the timer must be reset + * first! + */ + + mutex_lock(data->io_lock); + + /* 1. Reset the watchdog countdown counter */ + ret = sch56xx_write_virtual_reg(data->addr, SCH56XX_REG_WDOG_PRESET, + data->watchdog_preset); + if (ret) + goto leave; + + /* 2. Enable output */ + val = data->watchdog_output_enable | SCH56XX_WDOG_OUTPUT_ENABLE; + ret = sch56xx_write_virtual_reg(data->addr, + SCH56XX_REG_WDOG_OUTPUT_ENABLE, val); + if (ret) + goto leave; + + data->watchdog_output_enable = val; + + /* 3. Clear the watchdog event bit if set */ + val = inb(data->addr + 9); + if (val & 0x01) + outb(0x01, data->addr + 9); + +leave: + mutex_unlock(data->io_lock); + return ret; +} + +static int watchdog_trigger(struct watchdog_device *wddev) +{ + struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev); + int ret; + + /* Reset the watchdog countdown counter */ + mutex_lock(data->io_lock); + ret = sch56xx_write_virtual_reg(data->addr, SCH56XX_REG_WDOG_PRESET, + data->watchdog_preset); + mutex_unlock(data->io_lock); + + return ret; +} + +static int watchdog_stop(struct watchdog_device *wddev) +{ + struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev); + int ret = 0; + u8 val; + + val = data->watchdog_output_enable & ~SCH56XX_WDOG_OUTPUT_ENABLE; + mutex_lock(data->io_lock); + ret = sch56xx_write_virtual_reg(data->addr, + SCH56XX_REG_WDOG_OUTPUT_ENABLE, val); + mutex_unlock(data->io_lock); + if (ret) + return ret; + + data->watchdog_output_enable = val; + return 0; +} + +static void watchdog_ref(struct watchdog_device *wddev) +{ + struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev); + + kref_get(&data->kref); +} + +static void watchdog_unref(struct watchdog_device *wddev) +{ + struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev); + + kref_put(&data->kref, watchdog_release_resources); +} + +static const struct watchdog_ops watchdog_ops = { + .owner = THIS_MODULE, + .start = watchdog_start, + .stop = watchdog_stop, + .ping = watchdog_trigger, + .set_timeout = watchdog_set_timeout, + .ref = watchdog_ref, + .unref = watchdog_unref, +}; + +struct sch56xx_watchdog_data *sch56xx_watchdog_register(struct device *parent, + u16 addr, u32 revision, struct mutex *io_lock, int check_enabled) +{ + struct sch56xx_watchdog_data *data; + int err, control, output_enable; + + /* Cache the watchdog registers */ + mutex_lock(io_lock); + control = + sch56xx_read_virtual_reg(addr, SCH56XX_REG_WDOG_CONTROL); + output_enable = + sch56xx_read_virtual_reg(addr, SCH56XX_REG_WDOG_OUTPUT_ENABLE); + mutex_unlock(io_lock); + + if (control < 0) + return NULL; + if (output_enable < 0) + return NULL; + if (check_enabled && !(output_enable & SCH56XX_WDOG_OUTPUT_ENABLE)) { + pr_warn("Watchdog not enabled by BIOS, not registering\n"); + return NULL; + } + + data = kzalloc(sizeof(struct sch56xx_watchdog_data), GFP_KERNEL); + if (!data) + return NULL; + + data->addr = addr; + data->io_lock = io_lock; + kref_init(&data->kref); + + strlcpy(data->wdinfo.identity, "sch56xx watchdog", + sizeof(data->wdinfo.identity)); + data->wdinfo.firmware_version = revision; + data->wdinfo.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT; + if (!nowayout) + data->wdinfo.options |= WDIOF_MAGICCLOSE; + + data->wddev.info = &data->wdinfo; + data->wddev.ops = &watchdog_ops; + data->wddev.parent = parent; + data->wddev.timeout = 60; + data->wddev.min_timeout = 1; + data->wddev.max_timeout = 255 * 60; + if (nowayout) + set_bit(WDOG_NO_WAY_OUT, &data->wddev.status); + if (output_enable & SCH56XX_WDOG_OUTPUT_ENABLE) + set_bit(WDOG_ACTIVE, &data->wddev.status); + + /* Since the watchdog uses a downcounter there is no register to read + the BIOS set timeout from (if any was set at all) -> + Choose a preset which will give us a 1 minute timeout */ + if (control & SCH56XX_WDOG_TIME_BASE_SEC) + data->watchdog_preset = 60; /* seconds */ + else + data->watchdog_preset = 1; /* minute */ + + data->watchdog_control = control; + data->watchdog_output_enable = output_enable; + + watchdog_set_drvdata(&data->wddev, data); + err = watchdog_register_device(&data->wddev); + if (err) { + pr_err("Registering watchdog chardev: %d\n", err); + kfree(data); + return NULL; + } + + return data; +} +EXPORT_SYMBOL(sch56xx_watchdog_register); + +void sch56xx_watchdog_unregister(struct sch56xx_watchdog_data *data) +{ + watchdog_unregister_device(&data->wddev); + kref_put(&data->kref, watchdog_release_resources); + /* Don't touch data after this it may have been free-ed! */ +} +EXPORT_SYMBOL(sch56xx_watchdog_unregister); + +/* + * platform dev find, add and remove functions + */ + +static int __init sch56xx_find(int sioaddr, const char **name) { u8 devid; + unsigned short address; int err; err = superio_enter(sioaddr); @@ -261,20 +540,21 @@ static int __init sch56xx_find(int sioaddr, unsigned short *address, * Warning the order of the low / high byte is the other way around * as on most other superio devices!! */ - *address = superio_inb(sioaddr, SIO_REG_ADDR) | + address = superio_inb(sioaddr, SIO_REG_ADDR) | superio_inb(sioaddr, SIO_REG_ADDR + 1) << 8; - if (*address == 0) { + if (address == 0) { pr_warn("Base address not set\n"); err = -ENODEV; goto exit; } + err = address; exit: superio_exit(sioaddr); return err; } -static int __init sch56xx_device_add(unsigned short address, const char *name) +static int __init sch56xx_device_add(int address, const char *name) { struct resource res = { .start = address, @@ -314,15 +594,14 @@ exit_device_put: static int __init sch56xx_init(void) { - int err; - unsigned short address; - const char *name; - - err = sch56xx_find(0x4e, &address, &name); - if (err) - err = sch56xx_find(0x2e, &address, &name); - if (err) - return err; + int address; + const char *name = NULL; + + address = sch56xx_find(0x4e, &name); + if (address < 0) + address = sch56xx_find(0x2e, &name); + if (address < 0) + return address; return sch56xx_device_add(address, name); } |