mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 18:14:07 +08:00
4e2912901e
Kerneldoc expects struct properties to be documented using the syntax '@.*: ', but no ':' has been provided in 'struct it87_gpio's header. Add them to stop confusing kerneldoc. Fixes the following W=1 warnings: drivers/gpio/gpio-it87.c:69: warning: Function parameter or member 'chip' not described in 'it87_gpio' drivers/gpio/gpio-it87.c:69: warning: Function parameter or member 'lock' not described in 'it87_gpio' drivers/gpio/gpio-it87.c:69: warning: Function parameter or member 'io_base' not described in 'it87_gpio' drivers/gpio/gpio-it87.c:69: warning: Function parameter or member 'io_size' not described in 'it87_gpio' drivers/gpio/gpio-it87.c:69: warning: Function parameter or member 'output_base' not described in 'it87_gpio' drivers/gpio/gpio-it87.c:69: warning: Function parameter or member 'simple_base' not described in 'it87_gpio' drivers/gpio/gpio-it87.c:69: warning: Function parameter or member 'simple_size' not described in 'it87_gpio' Signed-off-by: Lee Jones <lee.jones@linaro.org> Cc: "Diego Elio Pettenò" <flameeyes@flameeyes.eu> Link: https://lore.kernel.org/r/20200630133345.2232932-8-lee.jones@linaro.org Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
421 lines
9.1 KiB
C
421 lines
9.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* GPIO interface for IT87xx Super I/O chips
|
|
*
|
|
* Author: Diego Elio Pettenò <flameeyes@flameeyes.eu>
|
|
* Copyright (c) 2017 Google, Inc.
|
|
*
|
|
* Based on it87_wdt.c by Oliver Schuster
|
|
* gpio-it8761e.c by Denis Turischev
|
|
* gpio-stmpe.c by Rabin Vincent
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#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/slab.h>
|
|
#include <linux/gpio/driver.h>
|
|
|
|
/* Chip Id numbers */
|
|
#define NO_DEV_ID 0xffff
|
|
#define IT8613_ID 0x8613
|
|
#define IT8620_ID 0x8620
|
|
#define IT8628_ID 0x8628
|
|
#define IT8718_ID 0x8718
|
|
#define IT8728_ID 0x8728
|
|
#define IT8732_ID 0x8732
|
|
#define IT8761_ID 0x8761
|
|
#define IT8772_ID 0x8772
|
|
#define IT8786_ID 0x8786
|
|
|
|
/* IO Ports */
|
|
#define REG 0x2e
|
|
#define VAL 0x2f
|
|
|
|
/* Logical device Numbers LDN */
|
|
#define GPIO 0x07
|
|
|
|
/* Configuration Registers and Functions */
|
|
#define LDNREG 0x07
|
|
#define CHIPID 0x20
|
|
#define CHIPREV 0x22
|
|
|
|
/**
|
|
* struct it87_gpio - it87-specific GPIO chip
|
|
* @chip: the underlying gpio_chip structure
|
|
* @lock: a lock to avoid races between operations
|
|
* @io_base: base address for gpio ports
|
|
* @io_size: size of the port rage starting from io_base.
|
|
* @output_base: Super I/O register address for Output Enable register
|
|
* @simple_base: Super I/O 'Simple I/O' Enable register
|
|
* @simple_size: Super IO 'Simple I/O' Enable register size; this is
|
|
* required because IT87xx chips might only provide Simple I/O
|
|
* switches on a subset of lines, whereas the others keep the
|
|
* same status all time.
|
|
*/
|
|
struct it87_gpio {
|
|
struct gpio_chip chip;
|
|
spinlock_t lock;
|
|
u16 io_base;
|
|
u16 io_size;
|
|
u8 output_base;
|
|
u8 simple_base;
|
|
u8 simple_size;
|
|
};
|
|
|
|
static struct it87_gpio it87_gpio_chip = {
|
|
.lock = __SPIN_LOCK_UNLOCKED(it87_gpio_chip.lock),
|
|
};
|
|
|
|
/* Superio chip access functions; copied from wdt_it87 */
|
|
|
|
static inline int superio_enter(void)
|
|
{
|
|
/*
|
|
* Try to reserve REG and REG + 1 for exclusive access.
|
|
*/
|
|
if (!request_muxed_region(REG, 2, KBUILD_MODNAME))
|
|
return -EBUSY;
|
|
|
|
outb(0x87, REG);
|
|
outb(0x01, REG);
|
|
outb(0x55, REG);
|
|
outb(0x55, REG);
|
|
return 0;
|
|
}
|
|
|
|
static inline void superio_exit(void)
|
|
{
|
|
outb(0x02, REG);
|
|
outb(0x02, VAL);
|
|
release_region(REG, 2);
|
|
}
|
|
|
|
static inline void superio_select(int ldn)
|
|
{
|
|
outb(LDNREG, REG);
|
|
outb(ldn, VAL);
|
|
}
|
|
|
|
static inline int superio_inb(int reg)
|
|
{
|
|
outb(reg, REG);
|
|
return inb(VAL);
|
|
}
|
|
|
|
static inline void superio_outb(int val, int reg)
|
|
{
|
|
outb(reg, REG);
|
|
outb(val, VAL);
|
|
}
|
|
|
|
static inline int superio_inw(int reg)
|
|
{
|
|
int val;
|
|
|
|
outb(reg++, REG);
|
|
val = inb(VAL) << 8;
|
|
outb(reg, REG);
|
|
val |= inb(VAL);
|
|
return val;
|
|
}
|
|
|
|
static inline void superio_outw(int val, int reg)
|
|
{
|
|
outb(reg++, REG);
|
|
outb(val >> 8, VAL);
|
|
outb(reg, REG);
|
|
outb(val, VAL);
|
|
}
|
|
|
|
static inline void superio_set_mask(int mask, int reg)
|
|
{
|
|
u8 curr_val = superio_inb(reg);
|
|
u8 new_val = curr_val | mask;
|
|
|
|
if (curr_val != new_val)
|
|
superio_outb(new_val, reg);
|
|
}
|
|
|
|
static inline void superio_clear_mask(int mask, int reg)
|
|
{
|
|
u8 curr_val = superio_inb(reg);
|
|
u8 new_val = curr_val & ~mask;
|
|
|
|
if (curr_val != new_val)
|
|
superio_outb(new_val, reg);
|
|
}
|
|
|
|
static int it87_gpio_request(struct gpio_chip *chip, unsigned gpio_num)
|
|
{
|
|
u8 mask, group;
|
|
int rc = 0;
|
|
struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
|
|
|
|
mask = 1 << (gpio_num % 8);
|
|
group = (gpio_num / 8);
|
|
|
|
spin_lock(&it87_gpio->lock);
|
|
|
|
rc = superio_enter();
|
|
if (rc)
|
|
goto exit;
|
|
|
|
/* not all the IT87xx chips support Simple I/O and not all of
|
|
* them allow all the lines to be set/unset to Simple I/O.
|
|
*/
|
|
if (group < it87_gpio->simple_size)
|
|
superio_set_mask(mask, group + it87_gpio->simple_base);
|
|
|
|
/* clear output enable, setting the pin to input, as all the
|
|
* newly-exported GPIO interfaces are set to input.
|
|
*/
|
|
superio_clear_mask(mask, group + it87_gpio->output_base);
|
|
|
|
superio_exit();
|
|
|
|
exit:
|
|
spin_unlock(&it87_gpio->lock);
|
|
return rc;
|
|
}
|
|
|
|
static int it87_gpio_get(struct gpio_chip *chip, unsigned gpio_num)
|
|
{
|
|
u16 reg;
|
|
u8 mask;
|
|
struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
|
|
|
|
mask = 1 << (gpio_num % 8);
|
|
reg = (gpio_num / 8) + it87_gpio->io_base;
|
|
|
|
return !!(inb(reg) & mask);
|
|
}
|
|
|
|
static int it87_gpio_direction_in(struct gpio_chip *chip, unsigned gpio_num)
|
|
{
|
|
u8 mask, group;
|
|
int rc = 0;
|
|
struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
|
|
|
|
mask = 1 << (gpio_num % 8);
|
|
group = (gpio_num / 8);
|
|
|
|
spin_lock(&it87_gpio->lock);
|
|
|
|
rc = superio_enter();
|
|
if (rc)
|
|
goto exit;
|
|
|
|
/* clear the output enable bit */
|
|
superio_clear_mask(mask, group + it87_gpio->output_base);
|
|
|
|
superio_exit();
|
|
|
|
exit:
|
|
spin_unlock(&it87_gpio->lock);
|
|
return rc;
|
|
}
|
|
|
|
static void it87_gpio_set(struct gpio_chip *chip,
|
|
unsigned gpio_num, int val)
|
|
{
|
|
u8 mask, curr_vals;
|
|
u16 reg;
|
|
struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
|
|
|
|
mask = 1 << (gpio_num % 8);
|
|
reg = (gpio_num / 8) + it87_gpio->io_base;
|
|
|
|
curr_vals = inb(reg);
|
|
if (val)
|
|
outb(curr_vals | mask, reg);
|
|
else
|
|
outb(curr_vals & ~mask, reg);
|
|
}
|
|
|
|
static int it87_gpio_direction_out(struct gpio_chip *chip,
|
|
unsigned gpio_num, int val)
|
|
{
|
|
u8 mask, group;
|
|
int rc = 0;
|
|
struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
|
|
|
|
mask = 1 << (gpio_num % 8);
|
|
group = (gpio_num / 8);
|
|
|
|
spin_lock(&it87_gpio->lock);
|
|
|
|
rc = superio_enter();
|
|
if (rc)
|
|
goto exit;
|
|
|
|
/* set the output enable bit */
|
|
superio_set_mask(mask, group + it87_gpio->output_base);
|
|
|
|
it87_gpio_set(chip, gpio_num, val);
|
|
|
|
superio_exit();
|
|
|
|
exit:
|
|
spin_unlock(&it87_gpio->lock);
|
|
return rc;
|
|
}
|
|
|
|
static const struct gpio_chip it87_template_chip = {
|
|
.label = KBUILD_MODNAME,
|
|
.owner = THIS_MODULE,
|
|
.request = it87_gpio_request,
|
|
.get = it87_gpio_get,
|
|
.direction_input = it87_gpio_direction_in,
|
|
.set = it87_gpio_set,
|
|
.direction_output = it87_gpio_direction_out,
|
|
.base = -1
|
|
};
|
|
|
|
static int __init it87_gpio_init(void)
|
|
{
|
|
int rc = 0, i;
|
|
u16 chip_type;
|
|
u8 chip_rev, gpio_ba_reg;
|
|
char *labels, **labels_table;
|
|
|
|
struct it87_gpio *it87_gpio = &it87_gpio_chip;
|
|
|
|
rc = superio_enter();
|
|
if (rc)
|
|
return rc;
|
|
|
|
chip_type = superio_inw(CHIPID);
|
|
chip_rev = superio_inb(CHIPREV) & 0x0f;
|
|
superio_exit();
|
|
|
|
it87_gpio->chip = it87_template_chip;
|
|
|
|
switch (chip_type) {
|
|
case IT8613_ID:
|
|
gpio_ba_reg = 0x62;
|
|
it87_gpio->io_size = 8; /* it8613 only needs 6, use 8 for alignment */
|
|
it87_gpio->output_base = 0xc8;
|
|
it87_gpio->simple_base = 0xc0;
|
|
it87_gpio->simple_size = 6;
|
|
it87_gpio->chip.ngpio = 64; /* has 48, use 64 for convenient calc */
|
|
break;
|
|
case IT8620_ID:
|
|
case IT8628_ID:
|
|
gpio_ba_reg = 0x62;
|
|
it87_gpio->io_size = 11;
|
|
it87_gpio->output_base = 0xc8;
|
|
it87_gpio->simple_size = 0;
|
|
it87_gpio->chip.ngpio = 64;
|
|
break;
|
|
case IT8718_ID:
|
|
case IT8728_ID:
|
|
case IT8732_ID:
|
|
case IT8772_ID:
|
|
case IT8786_ID:
|
|
gpio_ba_reg = 0x62;
|
|
it87_gpio->io_size = 8;
|
|
it87_gpio->output_base = 0xc8;
|
|
it87_gpio->simple_base = 0xc0;
|
|
it87_gpio->simple_size = 5;
|
|
it87_gpio->chip.ngpio = 64;
|
|
break;
|
|
case IT8761_ID:
|
|
gpio_ba_reg = 0x60;
|
|
it87_gpio->io_size = 4;
|
|
it87_gpio->output_base = 0xf0;
|
|
it87_gpio->simple_size = 0;
|
|
it87_gpio->chip.ngpio = 16;
|
|
break;
|
|
case NO_DEV_ID:
|
|
pr_err("no device\n");
|
|
return -ENODEV;
|
|
default:
|
|
pr_err("Unknown Chip found, Chip %04x Revision %x\n",
|
|
chip_type, chip_rev);
|
|
return -ENODEV;
|
|
}
|
|
|
|
rc = superio_enter();
|
|
if (rc)
|
|
return rc;
|
|
|
|
superio_select(GPIO);
|
|
|
|
/* fetch GPIO base address */
|
|
it87_gpio->io_base = superio_inw(gpio_ba_reg);
|
|
|
|
superio_exit();
|
|
|
|
pr_info("Found Chip IT%04x rev %x. %u GPIO lines starting at %04xh\n",
|
|
chip_type, chip_rev, it87_gpio->chip.ngpio,
|
|
it87_gpio->io_base);
|
|
|
|
if (!request_region(it87_gpio->io_base, it87_gpio->io_size,
|
|
KBUILD_MODNAME))
|
|
return -EBUSY;
|
|
|
|
/* Set up aliases for the GPIO connection.
|
|
*
|
|
* ITE documentation for recent chips such as the IT8728F
|
|
* refers to the GPIO lines as GPxy, with a coordinates system
|
|
* where x is the GPIO group (starting from 1) and y is the
|
|
* bit within the group.
|
|
*
|
|
* By creating these aliases, we make it easier to understand
|
|
* to which GPIO pin we're referring to.
|
|
*/
|
|
labels = kcalloc(it87_gpio->chip.ngpio, sizeof("it87_gpXY"),
|
|
GFP_KERNEL);
|
|
labels_table = kcalloc(it87_gpio->chip.ngpio, sizeof(const char *),
|
|
GFP_KERNEL);
|
|
|
|
if (!labels || !labels_table) {
|
|
rc = -ENOMEM;
|
|
goto labels_free;
|
|
}
|
|
|
|
for (i = 0; i < it87_gpio->chip.ngpio; i++) {
|
|
char *label = &labels[i * sizeof("it87_gpXY")];
|
|
|
|
sprintf(label, "it87_gp%u%u", 1+(i/8), i%8);
|
|
labels_table[i] = label;
|
|
}
|
|
|
|
it87_gpio->chip.names = (const char *const*)labels_table;
|
|
|
|
rc = gpiochip_add_data(&it87_gpio->chip, it87_gpio);
|
|
if (rc)
|
|
goto labels_free;
|
|
|
|
return 0;
|
|
|
|
labels_free:
|
|
kfree(labels_table);
|
|
kfree(labels);
|
|
release_region(it87_gpio->io_base, it87_gpio->io_size);
|
|
return rc;
|
|
}
|
|
|
|
static void __exit it87_gpio_exit(void)
|
|
{
|
|
struct it87_gpio *it87_gpio = &it87_gpio_chip;
|
|
|
|
gpiochip_remove(&it87_gpio->chip);
|
|
release_region(it87_gpio->io_base, it87_gpio->io_size);
|
|
kfree(it87_gpio->chip.names[0]);
|
|
kfree(it87_gpio->chip.names);
|
|
}
|
|
|
|
module_init(it87_gpio_init);
|
|
module_exit(it87_gpio_exit);
|
|
|
|
MODULE_AUTHOR("Diego Elio Pettenò <flameeyes@flameeyes.eu>");
|
|
MODULE_DESCRIPTION("GPIO interface for IT87xx Super I/O chips");
|
|
MODULE_LICENSE("GPL");
|