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/*
* Intel ICH6-10, Series 5 and 6 GPIO driver
*
* Copyright (C) 2010 Extreme Engineering Solutions.
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/gpio.h>
#include <linux/platform_device.h>
#include <linux/mfd/lpc_ich.h>
#define DRV_NAME "gpio_ich"
/*
* GPIO register offsets in GPIO I/O space.
* Each chunk of 32 GPIOs is manipulated via its own USE_SELx, IO_SELx, and
* LVLx registers. Logic in the read/write functions takes a register and
* an absolute bit number and determines the proper register offset and bit
* number in that register. For example, to read the value of GPIO bit 50
* the code would access offset ichx_regs[2(=GPIO_LVL)][1(=50/32)],
* bit 18 (50%32).
*/
enum GPIO_REG {
GPIO_USE_SEL = 0,
GPIO_IO_SEL,
GPIO_LVL,
GPO_BLINK
};
static const u8 ichx_regs[4][3] = {
{0x00, 0x30, 0x40}, /* USE_SEL[1-3] offsets */
{0x04, 0x34, 0x44}, /* IO_SEL[1-3] offsets */
{0x0c, 0x38, 0x48}, /* LVL[1-3] offsets */
{0x18, 0x18, 0x18}, /* BLINK offset */
};
static const u8 ichx_reglen[3] = {
0x30, 0x10, 0x10,
};
#define ICHX_WRITE(val, reg, base_res) outl(val, (reg) + (base_res)->start)
#define ICHX_READ(reg, base_res) inl((reg) + (base_res)->start)
struct ichx_desc {
/* Max GPIO pins the chipset can have */
uint ngpio;
/* Whether the chipset has GPIO in GPE0_STS in the PM IO region */
bool uses_gpe0;
/* USE_SEL is bogus on some chipsets, eg 3100 */
u32 use_sel_ignore[3];
/* Some chipsets have quirks, let these use their own request/get */
int (*request)(struct gpio_chip *chip, unsigned offset);
int (*get)(struct gpio_chip *chip, unsigned offset);
};
static struct {
spinlock_t lock;
struct platform_device *dev;
struct gpio_chip chip;
struct resource *gpio_base; /* GPIO IO base */
struct resource *pm_base; /* Power Mangagment IO base */
struct ichx_desc *desc; /* Pointer to chipset-specific description */
u32 orig_gpio_ctrl; /* Orig CTRL value, used to restore on exit */
u8 use_gpio; /* Which GPIO groups are usable */
} ichx_priv;
static int modparam_gpiobase = -1; /* dynamic */
module_param_named(gpiobase, modparam_gpiobase, int, 0444);
MODULE_PARM_DESC(gpiobase, "The GPIO number base. -1 means dynamic, "
"which is the default.");
static int ichx_write_bit(int reg, unsigned nr, int val, int verify)
{
unsigned long flags;
u32 data, tmp;
int reg_nr = nr / 32;
int bit = nr & 0x1f;
int ret = 0;
spin_lock_irqsave(&ichx_priv.lock, flags);
data = ICHX_READ(ichx_regs[reg][reg_nr], ichx_priv.gpio_base);
if (val)
data |= 1 << bit;
else
data &= ~(1 << bit);
ICHX_WRITE(data, ichx_regs[reg][reg_nr], ichx_priv.gpio_base);
tmp = ICHX_READ(ichx_regs[reg][reg_nr], ichx_priv.gpio_base);
if (verify && data != tmp)
ret = -EPERM;
spin_unlock_irqrestore(&ichx_priv.lock, flags);
return ret;
}
static int ichx_read_bit(int reg, unsigned nr)
{
unsigned long flags;
u32 data;
int reg_nr = nr / 32;
int bit = nr & 0x1f;
spin_lock_irqsave(&ichx_priv.lock, flags);
data = ICHX_READ(ichx_regs[reg][reg_nr], ichx_priv.gpio_base);
spin_unlock_irqrestore(&ichx_priv.lock, flags);
return data & (1 << bit) ? 1 : 0;
}
static bool ichx_gpio_check_available(struct gpio_chip *gpio, unsigned nr)
{
return !!(ichx_priv.use_gpio & (1 << (nr / 32)));
}
static int ichx_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
{
/*
* Try setting pin as an input and verify it worked since many pins
* are output-only.
*/
if (ichx_write_bit(GPIO_IO_SEL, nr, 1, 1))
return -EINVAL;
return 0;
}
static int ichx_gpio_direction_output(struct gpio_chip *gpio, unsigned nr,
int val)
{
/* Disable blink hardware which is available for GPIOs from 0 to 31. */
if (nr < 32)
ichx_write_bit(GPO_BLINK, nr, 0, 0);
/* Set GPIO output value. */
ichx_write_bit(GPIO_LVL, nr, val, 0);
/*
* Try setting pin as an output and verify it worked since many pins
* are input-only.
*/
if (ichx_write_bit(GPIO_IO_SEL, nr, 0, 1))
return -EINVAL;
return 0;
}
static int ichx_gpio_get(struct gpio_chip *chip, unsigned nr)
{
return ichx_read_bit(GPIO_LVL, nr);
}
static int ich6_gpio_get(struct gpio_chip *chip, unsigned nr)
{
unsigned long flags;
u32 data;
/*
* GPI 0 - 15 need to be read from the power management registers on
* a ICH6/3100 bridge.
*/
if (nr < 16) {
if (!ichx_priv.pm_base)
return -ENXIO;
spin_lock_irqsave(&ichx_priv.lock, flags);
/* GPI 0 - 15 are latched, write 1 to clear*/
ICHX_WRITE(1 << (16 + nr), 0, ichx_priv.pm_base);
data = ICHX_READ(0, ichx_priv.pm_base);
spin_unlock_irqrestore(&ichx_priv.lock, flags);
return (data >> 16) & (1 << nr) ? 1 : 0;
} else {
return ichx_gpio_get(chip, nr);
}
}
static int ichx_gpio_request(struct gpio_chip *chip, unsigned nr)
{
if (!ichx_gpio_check_available(chip, nr))
return -ENXIO;
/*
* Note we assume the BIOS properly set a bridge's USE value. Some
* chips (eg Intel 3100) have bogus USE values though, so first see if
* the chipset's USE value can be trusted for this specific bit.
* If it can't be trusted, assume that the pin can be used as a GPIO.
*/
if (ichx_priv.desc->use_sel_ignore[nr / 32] & (1 << (nr & 0x1f)))
return 0;
return ichx_read_bit(GPIO_USE_SEL, nr) ? 0 : -ENODEV;
}
static int ich6_gpio_request(struct gpio_chip *chip, unsigned nr)
{
/*
* Fixups for bits 16 and 17 are necessary on the Intel ICH6/3100
* bridge as they are controlled by USE register bits 0 and 1. See
* "Table 704 GPIO_USE_SEL1 register" in the i3100 datasheet for
* additional info.
*/
if (nr == 16 || nr == 17)
nr -= 16;
return ichx_gpio_request(chip, nr);
}
static void ichx_gpio_set(struct gpio_chip *chip, unsigned nr, int val)
{
ichx_write_bit(GPIO_LVL, nr, val, 0);
}
static void ichx_gpiolib_setup(struct gpio_chip *chip)
{
chip->owner = THIS_MODULE;
chip->label = DRV_NAME;
chip->dev = &ichx_priv.dev->dev;
/* Allow chip-specific overrides of request()/get() */
chip->request = ichx_priv.desc->request ?
ichx_priv.desc->request : ichx_gpio_request;
chip->get = ichx_priv.desc->get ?
ichx_priv.desc->get : ichx_gpio_get;
chip->set = ichx_gpio_set;
chip->direction_input = ichx_gpio_direction_input;
chip->direction_output = ichx_gpio_direction_output;
chip->base = modparam_gpiobase;
chip->ngpio = ichx_priv.desc->ngpio;
chip->can_sleep = false;
chip->dbg_show = NULL;
}
/* ICH6-based, 631xesb-based */
static struct ichx_desc ich6_desc = {
/* Bridges using the ICH6 controller need fixups for GPIO 0 - 17 */<
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