--- /dev/null
+/***************************************************************************
+ * 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);
Code Review / kvmfornfv.git / blobdiff