u-boot-brain/drivers/gpio/mpc8xxx_gpio.c
Rasmus Villemoes dd4cf53f98 gpio: mpc8xxx: don't do RMW on gpdat register when setting value
The driver correctly handles reading back the value of an output gpio
by reading from the shadow register for output, and from gpdat for
inputs.

Unfortunately, when setting the value of some gpio, we do a RMW cycle
on the gpdat register without taking the shadow register into account,
thus accidentally setting other output gpios (at least those whose
value cannot be read back) to 0 at the same time.

When changing a gpio from input to output, we still need to make sure
it initially has the requested value. So, the procedure is

- update the shadow register
- compute the new gpdir register
- write the bitwise and of the shadow and new gpdir register to gpdat
- write the new gpdir register

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
2020-03-31 10:06:52 -04:00

260 lines
6.3 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2016
* Mario Six, Guntermann & Drunck GmbH, mario.six@gdsys.cc
*
* based on arch/powerpc/include/asm/mpc85xx_gpio.h, which is
*
* Copyright 2010 eXMeritus, A Boeing Company
*/
#include <common.h>
#include <dm.h>
#include <mapmem.h>
#include <asm/gpio.h>
struct ccsr_gpio {
u32 gpdir;
u32 gpodr;
u32 gpdat;
u32 gpier;
u32 gpimr;
u32 gpicr;
};
struct mpc8xxx_gpio_data {
/* The bank's register base in memory */
struct ccsr_gpio __iomem *base;
/* The address of the registers; used to identify the bank */
ulong addr;
/* The GPIO count of the bank */
uint gpio_count;
/* The GPDAT register cannot be used to determine the value of output
* pins on MPC8572/MPC8536, so we shadow it and use the shadowed value
* for output pins
*/
u32 dat_shadow;
ulong type;
};
enum {
MPC8XXX_GPIO_TYPE,
MPC5121_GPIO_TYPE,
};
inline u32 gpio_mask(uint gpio)
{
return (1U << (31 - (gpio)));
}
static inline u32 mpc8xxx_gpio_get_val(struct ccsr_gpio *base, u32 mask)
{
return in_be32(&base->gpdat) & mask;
}
static inline u32 mpc8xxx_gpio_get_dir(struct ccsr_gpio *base, u32 mask)
{
return in_be32(&base->gpdir) & mask;
}
static inline int mpc8xxx_gpio_open_drain_val(struct ccsr_gpio *base, u32 mask)
{
return in_be32(&base->gpodr) & mask;
}
static inline void mpc8xxx_gpio_open_drain_on(struct ccsr_gpio *base, u32
gpios)
{
/* GPODR register 1 -> open drain on */
setbits_be32(&base->gpodr, gpios);
}
static inline void mpc8xxx_gpio_open_drain_off(struct ccsr_gpio *base,
u32 gpios)
{
/* GPODR register 0 -> open drain off (actively driven) */
clrbits_be32(&base->gpodr, gpios);
}
static int mpc8xxx_gpio_direction_input(struct udevice *dev, uint gpio)
{
struct mpc8xxx_gpio_data *data = dev_get_priv(dev);
u32 mask = gpio_mask(gpio);
/* GPDIR register 0 -> input */
clrbits_be32(&data->base->gpdir, mask);
return 0;
}
static int mpc8xxx_gpio_set_value(struct udevice *dev, uint gpio, int value)
{
struct mpc8xxx_gpio_data *data = dev_get_priv(dev);
struct ccsr_gpio *base = data->base;
u32 mask = gpio_mask(gpio);
u32 gpdir;
if (value) {
data->dat_shadow |= mask;
} else {
data->dat_shadow &= ~mask;
}
gpdir = in_be32(&base->gpdir);
gpdir |= gpio_mask(gpio);
out_be32(&base->gpdat, gpdir & data->dat_shadow);
out_be32(&base->gpdir, gpdir);
return 0;
}
static int mpc8xxx_gpio_direction_output(struct udevice *dev, uint gpio,
int value)
{
struct mpc8xxx_gpio_data *data = dev_get_priv(dev);
/* GPIO 28..31 are input only on MPC5121 */
if (data->type == MPC5121_GPIO_TYPE && gpio >= 28)
return -EINVAL;
return mpc8xxx_gpio_set_value(dev, gpio, value);
}
static int mpc8xxx_gpio_get_value(struct udevice *dev, uint gpio)
{
struct mpc8xxx_gpio_data *data = dev_get_priv(dev);
if (!!mpc8xxx_gpio_get_dir(data->base, gpio_mask(gpio))) {
/* Output -> use shadowed value */
return !!(data->dat_shadow & gpio_mask(gpio));
}
/* Input -> read value from GPDAT register */
return !!mpc8xxx_gpio_get_val(data->base, gpio_mask(gpio));
}
static int mpc8xxx_gpio_get_open_drain(struct udevice *dev, uint gpio)
{
struct mpc8xxx_gpio_data *data = dev_get_priv(dev);
return !!mpc8xxx_gpio_open_drain_val(data->base, gpio_mask(gpio));
}
static int mpc8xxx_gpio_set_open_drain(struct udevice *dev, uint gpio,
int value)
{
struct mpc8xxx_gpio_data *data = dev_get_priv(dev);
if (value)
mpc8xxx_gpio_open_drain_on(data->base, gpio_mask(gpio));
else
mpc8xxx_gpio_open_drain_off(data->base, gpio_mask(gpio));
return 0;
}
static int mpc8xxx_gpio_get_function(struct udevice *dev, uint gpio)
{
struct mpc8xxx_gpio_data *data = dev_get_priv(dev);
int dir;
dir = !!mpc8xxx_gpio_get_dir(data->base, gpio_mask(gpio));
return dir ? GPIOF_OUTPUT : GPIOF_INPUT;
}
#if CONFIG_IS_ENABLED(OF_CONTROL)
static int mpc8xxx_gpio_ofdata_to_platdata(struct udevice *dev)
{
struct mpc8xxx_gpio_plat *plat = dev_get_platdata(dev);
fdt_addr_t addr;
u32 reg[2];
dev_read_u32_array(dev, "reg", reg, 2);
addr = dev_translate_address(dev, reg);
plat->addr = addr;
plat->size = reg[1];
plat->ngpios = dev_read_u32_default(dev, "ngpios", 32);
return 0;
}
#endif
static int mpc8xxx_gpio_platdata_to_priv(struct udevice *dev)
{
struct mpc8xxx_gpio_data *priv = dev_get_priv(dev);
struct mpc8xxx_gpio_plat *plat = dev_get_platdata(dev);
unsigned long size = plat->size;
ulong driver_data = dev_get_driver_data(dev);
if (size == 0)
size = 0x100;
priv->addr = plat->addr;
priv->base = map_sysmem(plat->addr, size);
if (!priv->base)
return -ENOMEM;
priv->gpio_count = plat->ngpios;
priv->dat_shadow = 0;
priv->type = driver_data;
return 0;
}
static int mpc8xxx_gpio_probe(struct udevice *dev)
{
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
struct mpc8xxx_gpio_data *data = dev_get_priv(dev);
char name[32], *str;
mpc8xxx_gpio_platdata_to_priv(dev);
snprintf(name, sizeof(name), "MPC@%lx_", data->addr);
str = strdup(name);
if (!str)
return -ENOMEM;
uc_priv->bank_name = str;
uc_priv->gpio_count = data->gpio_count;
return 0;
}
static const struct dm_gpio_ops gpio_mpc8xxx_ops = {
.direction_input = mpc8xxx_gpio_direction_input,
.direction_output = mpc8xxx_gpio_direction_output,
.get_value = mpc8xxx_gpio_get_value,
.set_value = mpc8xxx_gpio_set_value,
.get_open_drain = mpc8xxx_gpio_get_open_drain,
.set_open_drain = mpc8xxx_gpio_set_open_drain,
.get_function = mpc8xxx_gpio_get_function,
};
static const struct udevice_id mpc8xxx_gpio_ids[] = {
{ .compatible = "fsl,pq3-gpio", .data = MPC8XXX_GPIO_TYPE },
{ .compatible = "fsl,mpc8308-gpio", .data = MPC8XXX_GPIO_TYPE },
{ .compatible = "fsl,mpc8349-gpio", .data = MPC8XXX_GPIO_TYPE },
{ .compatible = "fsl,mpc8572-gpio", .data = MPC8XXX_GPIO_TYPE},
{ .compatible = "fsl,mpc8610-gpio", .data = MPC8XXX_GPIO_TYPE},
{ .compatible = "fsl,mpc5121-gpio", .data = MPC5121_GPIO_TYPE, },
{ .compatible = "fsl,qoriq-gpio", .data = MPC8XXX_GPIO_TYPE },
{ /* sentinel */ }
};
U_BOOT_DRIVER(gpio_mpc8xxx) = {
.name = "gpio_mpc8xxx",
.id = UCLASS_GPIO,
.ops = &gpio_mpc8xxx_ops,
#if CONFIG_IS_ENABLED(OF_CONTROL)
.ofdata_to_platdata = mpc8xxx_gpio_ofdata_to_platdata,
.platdata_auto_alloc_size = sizeof(struct mpc8xxx_gpio_plat),
.of_match = mpc8xxx_gpio_ids,
#endif
.probe = mpc8xxx_gpio_probe,
.priv_auto_alloc_size = sizeof(struct mpc8xxx_gpio_data),
};