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/*
* Copyright (c) 2012 The Chromium OS Authors.
* SPDX-License-Identifier: GPL-2.0+
*/
/*
* This is a GPIO driver for Intel ICH6 and later. The x86 GPIOs are accessed
* through the PCI bus. Each PCI device has 256 bytes of configuration space,
* consisting of a standard header and a device-specific set of registers. PCI
* bus 0, device 31, function 0 gives us access to the chipset GPIOs (among
* other things). Within the PCI configuration space, the GPIOBASE register
* tells us where in the device's I/O region we can find more registers to
* actually access the GPIOs.
*
* PCI bus/device/function 0:1f:0 => PCI config registers
* PCI config register "GPIOBASE"
* PCI I/O space + [GPIOBASE] => start of GPIO registers
* GPIO registers => gpio pin function, direction, value
*
*
* Danger Will Robinson! Bank 0 (GPIOs 0-31) seems to be fairly stable. Most
* ICH versions have more, but the decoding the matrix that describes them is
* absurdly complex and constantly changing. We'll provide Bank 1 and Bank 2,
* but they will ONLY work for certain unspecified chipsets because the offset
* from GPIOBASE changes randomly. Even then, many GPIOs are unimplemented or
* reserved or subject to arcane restrictions.
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <fdtdec.h>
#include <pch.h>
#include <pci.h>
#include <asm/cpu.h>
#include <asm/gpio.h>
#include <asm/io.h>
#include <asm/pci.h>
DECLARE_GLOBAL_DATA_PTR;
#define GPIO_PER_BANK 32
struct ich6_bank_priv {
/* These are I/O addresses */
uint16_t use_sel;
uint16_t io_sel;
uint16_t lvl;
};
#define GPIO_USESEL_OFFSET(x) (x)
#define GPIO_IOSEL_OFFSET(x) (x + 4)
#define GPIO_LVL_OFFSET(x) (x + 8)
static int _ich6_gpio_set_value(uint16_t base, unsigned offset, int value)
{
u32 val;
val = inl(base);
if (value)
val |= (1UL << offset);
else
val &= ~(1UL << offset);
outl(val, base);
return 0;
}
static int _ich6_gpio_set_direction(uint16_t base, unsigned offset, int dir)
{
u32 val;
if (!dir) {
val = inl(base);
val |= (1UL << offset);
outl(val, base);
} else {
val = inl(base);
val &= ~(1UL << offset);
outl(val, base);
}
return 0;
}
static int gpio_ich6_ofdata_to_platdata(struct udevice *dev)
{
struct ich6_bank_platdata *plat = dev_get_platdata(dev);
u32 gpiobase;
int offset;
int ret;
ret = pch_get_gpio_base(dev->parent, &gpiobase);
if (ret)
return ret;
offset = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev), "reg", -1);
if (offset == -1) {
debug("%s: Invalid register offset %d\n", __func__, offset);
return -EINVAL;
}
plat->offset = offset;
plat->base_addr = gpiobase + offset;
plat->bank_name = fdt_getprop(gd->fdt_blob, dev_of_offset(dev),
"bank-name", NULL);
return 0;
}
static int ich6_gpio_probe(struct udevice *dev)
{
struct ich6_bank_platdata *plat = dev_get_platdata(dev);
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
struct ich6_bank_priv *bank = dev_get_priv(dev);
uc_priv->gpio_count = GPIO_PER_BANK;
uc_priv->bank_name = plat->bank_name;
bank->use_sel = plat->base_addr;
bank->io_sel = plat->base_addr + 4;
bank->lvl = plat->base_addr + 8;
return 0;
}
static int ich6_gpio_request(struct udevice *dev, unsigned offset,
const char *label)
{
struct ich6_bank_priv *bank = dev_get_priv(dev);
u32 tmplong;
/*
* Make sure that the GPIO pin we want isn't already in use for some
* built-in hardware function. We have to check this for every
* requested pin.
*/
tmplong = inl(bank->use_sel);
if (!(tmplong & (1UL << offset))) {
debug("%s: gpio %d is reserved for internal use\n", __func__,
offset);
return -EPERM;
}
return 0;
}
static int ich6_gpio_direction_input(struct udevice *dev, unsigned offset)
{
struct ich6_bank_priv *bank = dev_get_priv(dev);
return _ich6_gpio_set_direction(bank->io_sel, offset, 0);
}
static int ich6_gpio_direction_output(struct udevice *dev, unsigned offset,
int value)
{
int ret;
struct ich6_bank_priv *bank = dev_get_priv(dev);
ret = _ich6_gpio_set_direction(bank->io_sel, offset, 1);
if (ret)
return ret;
return _ich6_gpio_set_value(bank->lvl, offset, value);
}
static int ich6_gpio_get_value(struct udevice *dev, unsigned offset)
{
struct ich6_bank_priv *bank = dev_get_priv(dev);
u32 tmplong;
int r;
tmplong = inl(bank->lvl);
r = (tmplong & (1UL << offset)) ? 1 : 0;
return r;
}
static int ich6_gpio_set_value(struct udevice *dev, unsigned offset,
int value)
{
struct ich6_bank_priv *bank = dev_get_priv(dev);
return _ich6_gpio_set_value(bank->lvl, offset, value);
}
static int ich6_gpio_get_function(struct udevice *dev, unsigned offset)
{
struct ich6_bank_priv *bank = dev_get_priv(dev);
u32 mask = 1UL << offset;
if (!(inl(bank->use_sel) & mask))
return GPIOF_FUNC;
if (inl(bank->io_sel) & mask)
return GPIOF_INPUT;
else
return GPIOF_OUTPUT;
}
static const struct dm_gpio_ops gpio_ich6_ops = {
.request = ich6_gpio_request,
.direction_input = ich6_gpio_direction_input,
.direction_output = ich6_gpio_direction_output,
.get_value = ich6_gpio_get_value,
.set_value = ich6_gpio_set_value,
.get_function = ich6_gpio_get_function,
};
static const struct udevice_id intel_ich6_gpio_ids[] = {
{ .compatible = "intel,ich6-gpio" },
{ }
};
U_BOOT_DRIVER(gpio_ich6) = {
.name = "gpio_ich6",
.id = UCLASS_GPIO,
.of_match = intel_ich6_gpio_ids,
.ops = &gpio_ich6_ops,
.ofdata_to_platdata = gpio_ich6_ofdata_to_platdata,
.probe = ich6_gpio_probe,
.priv_auto_alloc_size = sizeof(struct ich6_bank_priv),
.platdata_auto_alloc_size = sizeof(struct ich6_bank_platdata),
};
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