/***************************************************************************
* Copyright (C) 2010-2011 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 "sch56xx-common.h"
#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 9
#define SCH56XX_CMD_READ 0x02
#define SCH56XX_CMD_WRITE 0x03
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);
static int __init sch56xx_find(int sioaddr, unsigned short *address,
const char **name)
{
u8 devid;
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;
}
exit:
superio_exit(sioaddr);
return err;
}
static int __init sch56xx_device_add(unsigned short 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 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;
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);
