linux/drivers/hwmon/sch56xx-common.c
Thomas Gleixner 1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00

577 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/***************************************************************************
* Copyright (C) 2010-2012 Hans de Goede <hdegoede@redhat.com> *
* *
***************************************************************************/
#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/uaccess.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 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
*/
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 const struct watchdog_ops watchdog_ops = {
.owner = THIS_MODULE,
.start = watchdog_start,
.stop = watchdog_stop,
.ping = watchdog_trigger,
.set_timeout = watchdog_set_timeout,
};
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;
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);
kfree(data);
}
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);