diff options
Diffstat (limited to 'drivers/hwmon/sch56xx-common.c')
| -rw-r--r-- | drivers/hwmon/sch56xx-common.c | 619 |
1 files changed, 619 insertions, 0 deletions
diff --git a/drivers/hwmon/sch56xx-common.c b/drivers/hwmon/sch56xx-common.c new file mode 100644 index 000000000..738681983 --- /dev/null +++ b/drivers/hwmon/sch56xx-common.c @@ -0,0 +1,619 @@ +/*************************************************************************** + * 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 * + * the Free Software Foundation; either version 2 of the License, or * + * (at your option) any later version. * + * * + * This program is distributed in the hope that it will be useful, * + * but WITHOUT ANY WARRANTY; without even the implied warranty of * + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * + * GNU General Public License for more details. * + * * + * You should have received a copy of the GNU General Public License * + * along with this program; if not, write to the * + * Free Software Foundation, Inc., * + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * + ***************************************************************************/ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/err.h> +#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 */ + +#define SIO_REG_LDSEL 0x07 /* Logical device select */ +#define SIO_REG_DEVID 0x20 /* Device ID */ +#define SIO_REG_ENABLE 0x30 /* Logical device enable */ +#define SIO_REG_ADDR 0x66 /* Logical device address (2 bytes) */ + +#define SIO_SCH5627_ID 0xC6 /* Chipset ID */ +#define SIO_SCH5636_ID 0xC7 /* Chipset ID */ + +#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 */ +static inline int superio_inb(int base, int reg) +{ + outb(reg, base); + return inb(base + 1); +} + +static inline int superio_enter(int base) +{ + /* Don't step on other drivers' I/O space by accident */ + if (!request_muxed_region(base, 2, "sch56xx")) { + pr_err("I/O address 0x%04x already in use\n", base); + return -EBUSY; + } + + outb(SIO_UNLOCK_KEY, base); + + return 0; +} + +static inline void superio_select(int base, int ld) +{ + outb(SIO_REG_LDSEL, base); + outb(ld, base + 1); +} + +static inline void superio_exit(int base) +{ + outb(SIO_LOCK_KEY, base); + release_region(base, 2); +} + +static int sch56xx_send_cmd(u16 addr, u8 cmd, u16 reg, u8 v) +{ + u8 val; + int i; + /* + * According to SMSC for the commands we use the maximum time for + * the EM to respond is 15 ms, but testing shows in practice it + * responds within 15-32 reads, so we first busy poll, and if + * that fails sleep a bit and try again until we are way past + * the 15 ms maximum response time. + */ + const int max_busy_polls = 64; + const int max_lazy_polls = 32; + + /* (Optional) Write-Clear the EC to Host Mailbox Register */ + val = inb(addr + 1); + outb(val, addr + 1); + + /* Set Mailbox Address Pointer to first location in Region 1 */ + outb(0x00, addr + 2); + outb(0x80, addr + 3); + + /* Write Request Packet Header */ + outb(cmd, addr + 4); /* VREG Access Type read:0x02 write:0x03 */ + outb(0x01, addr + 5); /* # of Entries: 1 Byte (8-bit) */ + outb(0x04, addr + 2); /* Mailbox AP to first data entry loc. */ + + /* Write Value field */ + if (cmd == SCH56XX_CMD_WRITE) + outb(v, addr + 4); + + /* Write Address field */ + outb(reg & 0xff, addr + 6); + outb(reg >> 8, addr + 7); + + /* Execute the Random Access Command */ + outb(0x01, addr); /* Write 01h to the Host-to-EC register */ + + /* EM Interface Polling "Algorithm" */ + for (i = 0; i < max_busy_polls + max_lazy_polls; i++) { + if (i >= max_busy_polls) + msleep(1); + /* Read Interrupt source Register */ + val = inb(addr + 8); + /* Write Clear the interrupt source bits */ + if (val) + outb(val, addr + 8); + /* Command Completed ? */ + if (val & 0x01) + break; + } + if (i == max_busy_polls + max_lazy_polls) { + pr_err("Max retries exceeded reading virtual register 0x%04hx (%d)\n", + reg, 1); + return -EIO; + } + + /* + * According to SMSC we may need to retry this, but sofar I've always + * seen this succeed in 1 try. + */ + for (i = 0; i < max_busy_polls; i++) { + /* Read EC-to-Host Register */ + val = inb(addr + 1); + /* Command Completed ? */ + if (val == 0x01) + break; + + if (i == 0) + 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); + return -EIO; + } + + /* + * According to the SMSC app note we should now do: + * + * Set Mailbox Address Pointer to first location in Region 1 * + * outb(0x00, addr + 2); + * outb(0x80, addr + 3); + * + * But if we do that things don't work, so let's not. + */ + + /* Read Value field */ + if (cmd == SCH56XX_CMD_READ) + return inb(addr + 4); + + return 0; +} + +int sch56xx_read_virtual_reg(u16 addr, u16 reg) +{ + return sch56xx_send_cmd(addr, SCH56XX_CMD_READ, reg, 0); +} +EXPORT_SYMBOL(sch56xx_read_virtual_reg); + +int sch56xx_write_virtual_reg(u16 addr, u16 reg, u8 val) +{ + return sch56xx_send_cmd(addr, SCH56XX_CMD_WRITE, reg, val); +} +EXPORT_SYMBOL(sch56xx_write_virtual_reg); + +int sch56xx_read_virtual_reg16(u16 addr, u16 reg) +{ + int lsb, msb; + + /* Read LSB first, this will cause the matching MSB to be latched */ + lsb = sch56xx_read_virtual_reg(addr, reg); + if (lsb < 0) + return lsb; + + msb = sch56xx_read_virtual_reg(addr, reg + 1); + if (msb < 0) + return msb; + + return lsb | (msb << 8); +} +EXPORT_SYMBOL(sch56xx_read_virtual_reg16); + +int sch56xx_read_virtual_reg12(u16 addr, u16 msb_reg, u16 lsn_reg, + int high_nibble) +{ + int msb, lsn; + + /* Read MSB first, this will cause the matching LSN to be latched */ + msb = sch56xx_read_virtual_reg(addr, msb_reg); + if (msb < 0) + return msb; + + lsn = sch56xx_read_virtual_reg(addr, lsn_reg); + if (lsn < 0) + return lsn; + + if (high_nibble) + return (msb << 4) | (lsn >> 4); + else + return (msb << 4) | (lsn & 0x0f); +} +EXPORT_SYMBOL(sch56xx_read_virtual_reg12); + +/* + * 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); + if (err) + return err; + + devid = superio_inb(sioaddr, SIO_REG_DEVID); + switch (devid) { + case SIO_SCH5627_ID: + *name = "sch5627"; + break; + case SIO_SCH5636_ID: + *name = "sch5636"; + break; + default: + pr_debug("Unsupported device id: 0x%02x\n", + (unsigned int)devid); + err = -ENODEV; + goto exit; + } + + superio_select(sioaddr, SIO_SCH56XX_LD_EM); + + if (!(superio_inb(sioaddr, SIO_REG_ENABLE) & 0x01)) { + pr_warn("Device not activated\n"); + err = -ENODEV; + goto exit; + } + + /* + * 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) | + superio_inb(sioaddr, SIO_REG_ADDR + 1) << 8; + 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(int address, const char *name) +{ + struct resource res = { + .start = address, + .end = address + REGION_LENGTH - 1, + .flags = IORESOURCE_IO, + }; + int err; + + sch56xx_pdev = platform_device_alloc(name, address); + if (!sch56xx_pdev) + return -ENOMEM; + + res.name = sch56xx_pdev->name; + err = acpi_check_resource_conflict(&res); + if (err) + goto exit_device_put; + + err = platform_device_add_resources(sch56xx_pdev, &res, 1); + if (err) { + pr_err("Device resource addition failed\n"); + goto exit_device_put; + } + + err = platform_device_add(sch56xx_pdev); + if (err) { + pr_err("Device addition failed\n"); + goto exit_device_put; + } + + return 0; + +exit_device_put: + platform_device_put(sch56xx_pdev); + + return err; +} + +static int __init sch56xx_init(void) +{ + 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); +} + +static void __exit sch56xx_exit(void) +{ + platform_device_unregister(sch56xx_pdev); +} + +MODULE_DESCRIPTION("SMSC SCH56xx Hardware Monitoring Common Code"); +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); +MODULE_LICENSE("GPL"); + +module_init(sch56xx_init); +module_exit(sch56xx_exit); |