/*
* 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,
};
static const u8 ichx_regs[3][3] = {
{0x00, 0x30, 0x40}, /* USE_SEL[1-3] offsets */
{0x04, 0x34, 0x44}, /* IO_SEL[1-3] offsets */
{0x0c, 0x38, 0x48}, /* LVL[1-3] offsets */
};
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)
{
/* 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 = 0;
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 */
.request = ich6_gpio_request,
.get = ich6_gpio_get,
/* GPIO 0-15 are read in the GPE0_STS PM register */
.uses_gpe0 = true,
.ngpio = 50,
};
/* Intel 3100 */
static struct ichx_desc i3100_desc = {
/*
* Bits 16,17, 20 of USE_SEL and bit 16 of USE_SEL2 always read 0 on
* the Intel 3100. See "Table 712. GPIO Summary Table" of 3100
* Datasheet for more info.
*/
.use_sel_ignore = {0x00130000, 0x00010000, 0x0},
/* The 3100 needs fixups for GPIO 0 - 17 */
.request = ich6_gpio_request,
.get = ich6_gpio_get,
/* GPIO 0-15 are read in the GPE0_STS PM register */
.uses_gpe0 = true,
.ngpio = 50,
};
/* ICH7 and ICH8-based */
static struct ichx_desc ich7_desc = {
.ngpio = 50,
};
/* ICH9-based */
static struct ichx_desc ich9_desc = {
.ngpio = 61,
};
/* ICH10-based - Consumer/corporate versions have different amount of GPIO */
static struct ichx_desc ich10_cons_desc = {
.ngpio = 61,
};
static struct ichx_desc ich10_corp_desc = {
.ngpio = 72,
};
/* Intel 5 series, 6 series, 3400 series, and C200 series */
static struct ichx_desc intel5_desc = {
.ngpio = 76,
};
static int ichx_gpio_request_regions(struct resource *res_base,
const char *name, u8 use_gpio)
{
int i;
if (!res_base || !res_base->start || !res_base->end)
return -ENODEV;
for (i = 0; i < ARRAY_SIZE(ichx_regs[0]); i++) {
if (!(use_gpio & (1 << i)))
continue;
if (!request_region(res_base->start + ichx_regs[0][i],
ichx_reglen[i], name))
goto request_err;
}
return 0;
request_err:
/* Clean up: release already requested regions, if any */
for (i--; i >= 0; i--) {
if (!(use_gpio & (1 << i)))
continue;
release_region(res_base->start + ichx_regs[0][i],
ichx_reglen[i]);
}
return -EBUSY;
}
static void ichx_gpio_release_regions(struct resource *res_base, u8 use_gpio)
{
int i;
for (i = 0; i < ARRAY_SIZE(ichx_regs[0]); i++) {
if (!(use_gpio & (1 << i)))
continue;
release_region(res_base->start + ichx_regs[0][i],
ichx_reglen[i]);
}
}
static int ichx_gpio_probe(struct platform_device *pdev)
{
struct resource *res_base, *res_pm;
int err;
struct lpc_ich_info *ich_info = pdev->dev.platform_data;
if (!ich_info)
return -ENODEV;
ichx_priv.dev = pdev;
switch (ich_info->gpio_version) {
case ICH_I3100_GPIO:
ichx_priv.desc = &i3100_desc;
break;
case ICH_V5_GPIO:
ichx_priv.desc = &intel5_desc;
break;
case ICH_V6_GPIO:
ichx_priv.desc = &ich6_desc;
break;
case ICH_V7_GPIO:
ichx_priv.desc = &ich7_desc;
break;
case ICH_V9_GPIO:
ichx_priv.desc = &ich9_desc;
break;
case ICH_V10CORP_GPIO:
ichx_priv.desc = &ich10_corp_desc;
break;
case ICH_V10CONS_GPIO:
ichx_priv.desc = &ich10_cons_desc;
break;
default:
return -ENODEV;
}
spin_lock_init(&ichx_priv.lock);
res_base = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_GPIO);
ichx_priv.use_gpio = ich_info->use_gpio;
err = ichx_gpio_request_regions(res_base, pdev->name,
ichx_priv.use_gpio);
if (err)
return err;
ichx_priv.gpio_base = res_base;
/*
* If necessary, determine the I/O address of ACPI/power management
* registers which are needed to read the the GPE0 register for GPI pins
* 0 - 15 on some chipsets.
*/
if (!ichx_priv.desc->uses_gpe0)
goto init;
res_pm = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_GPE0);
if (!res_pm) {
pr_warn("ACPI BAR is unavailable, GPI 0 - 15 unavailable\n");
goto init;
}
if (!request_region(res_pm->start, resource_size(res_pm),
pdev->name)) {
pr_warn("ACPI BAR is busy, GPI 0 - 15 unavailable\n");
goto init;
}
ichx_priv.pm_base = res_pm;
init:
ichx_gpiolib_setup(&ichx_priv.chip);
err = gpiochip_add(&ichx_priv.chip);
if (err) {
pr_err("Failed to register GPIOs\n");
goto add_err;
}
pr_info("GPIO from %d to %d on %s\n", ichx_priv.chip.base,
ichx_priv.chip.base + ichx_priv.chip.ngpio - 1, DRV_NAME);
return 0;
add_err:
ichx_gpio_release_regions(ichx_priv.gpio_base, ichx_priv.use_gpio);
if (ichx_priv.pm_base)
release_region(ichx_priv.pm_base->start,
resource_size(ichx_priv.pm_base));
return err;
}
static int ichx_gpio_remove(struct platform_device *pdev)
{
int err;
err = gpiochip_remove(&ichx_priv.chip);
if (err) {
dev_err(&pdev->dev, "%s failed, %d\n",
"gpiochip_remove()", err);
return err;
}
ichx_gpio_release_regions(ichx_priv.gpio_base, ichx_priv.use_gpio);
if (ichx_priv.pm_base)
release_region(ichx_priv.pm_base->start,
resource_size(ichx_priv.pm_base));
return 0;
}
static struct platform_driver ichx_gpio_driver = {
.driver = {
.owner = THIS_MODULE,
.name = DRV_NAME,
},
.probe = ichx_gpio_probe,
.remove = ichx_gpio_remove,
};
module_platform_driver(ichx_gpio_driver);
MODULE_AUTHOR("Peter Tyser <ptyser@xes-inc.com>");
MODULE_DESCRIPTION("GPIO interface for Intel ICH series");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:"DRV_NAME);
