Re: Fintek F81865 chip (Wdog support)

From: BrunoFerreira
Date: Fri Aug 02 2013 - 10:56:30 EST

Hi All.

Sorry about the delay.
Please find in attach the driver source code with support for this chip.

Kind regards,
Bruno Ferreira

On 05/26/2013 05:44 PM, Wim Van Sebroeck wrote:
Hi All,

On Wed, 13 Mar 2013 15:04:38 +0000, BrunoFerreira wrote:
I'm currently working with a new board iEi NOVA-PV-D5251 [1] that
have the Fintek F81865 chip for Super I/O support and I will need to
develop the watchdog driver and another to access to the IO that this
board supports (gpio). I made a search and I see that already exists
driver for F71808E chip, I use this driver as an example an I made a
new driver for F81865 chip. My driver is working pretty well, but
a question that I can't find the answer on datasheet of this chip
may be Wim or Giel could know.
On both chips, we need to configure a pin that can work as a normal
GPIO (F81865: Set pin 70 the function of WDTRST#/GPIO15 is WDTRST# |
F71808E: Set pin 21 to GPIO23/WDTRST#, then to WDTRST#), this is here
where I get myself confused, this WDTRST will be mapped in any GPIO
output on my board? I mean, if the watchdog is enable I will get any
output pin set to 1 (i.e. the GPIO15, output 5?) and when the
goes down this output goes to 0?
Sorry, I can't give you a definite answer on that. All Fintek
datasheets I've seen are very poorly written. At one point I actually
stopped trusting the datasheet enough to go through the hassle of
hooking up a scope to the pins of the chip.

Hazarding a guess however, I'd say that when the watchdog is enabled
you cannot use the WDTRST pin as a GPIO pin.

The other question is to Wim, can you tell me if there is interest in
add this chip support to kernel?
This would be a yes, unless there are good reasons not to include it in
The answer is indeed yes. Has a patch been created since this message?

Kind regards,

* Copyright (C) 2013 Bruno Ferreira <bruno.ferreira@xxxxxxxxxx> *
* *
* 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 *
* 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. *

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/errno.h>
#include <linux/ioport.h>

#include <linux/gpio.h>

#define DRVNAME "f81865_gpio"

/* Global Control Registers */
#define SIO_F81865_LD_WDT 0x07 /* Watchdog Logic Number Register (LDN) */
#define SIO_F81865_LD_GPIO 0x06 /* GPIO Logic Number Register (LDN) */
#define SIO_UNLOCK_KEY 0x87 /* Key to enable Super-I/O */
#define SIO_LOCK_KEY 0xAA /* Key to diasble Super-I/O */

#define SIO_REG_DEVID 0x20 /* Device ID (2 bytes) */
#define SIO_REG_DEVREV 0x22 /* Device revision */
#define SIO_REG_MANID 0x23 /* Fintek ID (2 bytes) */

/* Manufacture and Chip Information */
#define SIO_FINTEK_ID 0x1934 /* Manufacturers ID */
#define SIO_F81865_ID 0x0704 /* Chipset ID*/

static DEFINE_SPINLOCK(gpio_lock);

/* GPIO internal data information */
struct gpio_data {
unsigned short sioaddr; /* default index port */
unsigned long opened; /* driver open state */

static struct gpio_data gpio = {};

/* Super-I/O Function prototypes */
static inline int superio_enter(int base);
static inline void superio_exit(int base);
static inline int superio_inb(int base, int reg);
static inline void superio_outb(int base, int reg, u8 val);
static inline int superio_inw(int base, int reg);

static inline void superio_set_bit(int base, int reg, int bit);
static inline void superio_clear_bit(int base, int reg, int bit);

/* Super I/O functions */
static inline int superio_enter(int base)
/* don't step on other drivers' I/O space by accident */
if (!request_muxed_region(base, 2, DRVNAME)) {
printk(KERN_ERR DRVNAME ": I/O address 0x%04x already in use\n", (int)base);
return -EBUSY;

/* according to the datasheet the key must be send twice! */
outb(SIO_UNLOCK_KEY, base);
outb(SIO_UNLOCK_KEY, base);

return 0;

static inline void superio_exit(int base)
outb(SIO_LOCK_KEY, base);
release_region(base, 2);

static inline int superio_inb(int base, int reg)
outb(reg, base);
return inb(base + 1);

static inline void superio_outb(int base, int reg, u8 val)
outb(reg, base);
outb(val, base + 1);

static int superio_inw(int base, int reg)
int val;
val = superio_inb(base, reg) << 8;
val |= superio_inb(base, reg + 1);
return val;

static inline void superio_set_bit(int base, int reg, int bit)
unsigned long val = superio_inb(base, reg);
__set_bit(bit, &val);
superio_outb(base, reg, val);

static inline void superio_clear_bit(int base, int reg, int bit)
unsigned long val = superio_inb(base, reg);
__clear_bit(bit, &val);
superio_outb(base, reg, val);

/* GPIO api */
static int f81865_gpio_direction_in(struct gpio_chip *gc, unsigned _gpio_num)
return 0;

static int f81865_gpio_direction_out(struct gpio_chip *gc, unsigned _gpio_num, int val)
return 0;

static int f81865_gpio_get(struct gpio_chip *gc, unsigned _gpio_num)
return 0;

static void f81865_gpio_set(struct gpio_chip *gc, unsigned _gpio_num, int val)


static struct gpio_chip f81865_gpio_chip =
.label = DRVNAME,
.owner = THIS_MODULE,
.get = f81865_gpio_get,
.direction_input = f81865_gpio_direction_in,
.set = f81865_gpio_set,
.direction_output = f81865_gpio_direction_out,

/* Driver useful functions */
static int __init f81865_configure(void)
int err = 0;
/* temporary */
//u8 io_reg, curr_vals;

/* Enable all pins with GPIO capability */
/* By default we enable all possible GPIOs on the chip */
err = superio_enter(gpio.sioaddr);
if (err) goto exit_unlock;

/* Enable GPIO... */

//io_reg = 0x27; /* Enable Rom Address Register */
//curr_vals = superio_inb(gpio.sioaddr, io_reg);
//printk(KERN_INFO DRVNAME ": Rom Address Register: (%d) \n", curr_vals);
//superio_set_bit(gpio.sioaddr, io_reg, 4); /* PORT_4E_EN to 1*/

/* Enable GPIO[10-17], GPIO1 | WARNING the GPIO15 could be the WDTRST# */
/* GPIO1 Enable Register - Index 2Bh */
superio_outb(gpio.sioaddr, 0x2b, 0xff);

/* Enable GPIO[20-27], GPIO1 */
/* GPIO2 Enable Register - Index 2Ch */
superio_outb(gpio.sioaddr, 0x2c, 0xff);

/* Enable GPIO[30-37], GPIO1 */
/* GPIO3 Enable Register - Index 29h */
superio_outb(gpio.sioaddr, 0x29, 0xff);

/* Enable GPIO[40-47], GPIO1 */
/* GPIO4 Enable Register - Index 28h */
superio_outb(gpio.sioaddr, 0x28, 0xff);



printk(KERN_INFO DRVNAME ": configured(%d)...\n", err);
return err;

static int __init f81865_find(int sio_addr)
u16 devid;
int err = superio_enter(sio_addr);
if (err) return err;

devid = superio_inw(sio_addr, SIO_REG_MANID);
if (devid != SIO_FINTEK_ID) {
pr_debug(DRVNAME ": Not a Fintek device\n");
err = -ENODEV;
goto exit;

devid = superio_inw(sio_addr, SIO_REG_DEVID);
if (devid != SIO_F81865_ID) {
printk(KERN_INFO DRVNAME ": Unrecognized Fintek device: %04x\n", (unsigned int) devid);
err = -ENODEV;
goto exit;

printk(KERN_INFO DRVNAME ": Found F81865 Super I/O chip, revision %d\n", (int) superio_inb(sio_addr, SIO_REG_DEVREV));


return err;

static int __init f81865_gpio_init(void)
static const unsigned short addrs[] = { 0x2e, 0x4e };
int err = -ENODEV, i;

for (i=0; i < ARRAY_SIZE(addrs); i++) {
err = f81865_find(addrs[i]);
if (err == 0) break;
if (i == ARRAY_SIZE(addrs)) return err;

/* set GPIO base address */
gpio.sioaddr = addrs[i];

/* configure GPIO pins capability */
err = f81865_configure();
if (err)
printk(KERN_ERR DRVNAME ": configuring the GPIO...\n");
return EAGAIN;

f81865_gpio_chip.base = -1;
f81865_gpio_chip.ngpio = 26; /* !!! FIX THIS !!! */

err = gpiochip_add(&f81865_gpio_chip);

return (err < 0) ? err : 0;

static void __exit f81865_gpio_exit(void)
printk(KERN_INFO DRVNAME ": unloaded...\n");

MODULE_AUTHOR("Bruno Ferreira");
MODULE_DESCRIPTION("GPIO interface for F81865 Super I/O chip");