u-boot/drivers/gpio/tegra_gpio.c
Simon Glass 651827c0fc tegra: gpio: Show the GPIO value for outputs
The tegra GPIO controller has two ways of reading the value of a GPIO. It
can supply the 'input' value (which is the value read from the pin) and the
'output' value (which is the value being driven from the pin. With a GPIO
set to output mode, the 'input' value is always low which is not very
useful.

This has the unfortunate result that setting a GPIO high still leaves it
showing as low in the 'gpio status' command.

Adjust the driver to check which direction the GPIO is set to, then read
the value from the appropriate register: 'input' for input GPIOs, 'output'
for output GPIOs.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
2016-02-16 09:17:50 -07:00

383 lines
9.6 KiB
C

/*
* NVIDIA Tegra20 GPIO handling.
* (C) Copyright 2010-2012,2015
* NVIDIA Corporation <www.nvidia.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
/*
* Based on (mostly copied from) kw_gpio.c based Linux 2.6 kernel driver.
* Tom Warren (twarren@nvidia.com)
*/
#include <common.h>
#include <dm.h>
#include <malloc.h>
#include <errno.h>
#include <fdtdec.h>
#include <asm/io.h>
#include <asm/bitops.h>
#include <asm/arch/tegra.h>
#include <asm/gpio.h>
#include <dm/device-internal.h>
#include <dt-bindings/gpio/gpio.h>
DECLARE_GLOBAL_DATA_PTR;
static const int CONFIG_SFIO = 0;
static const int CONFIG_GPIO = 1;
static const int DIRECTION_INPUT = 0;
static const int DIRECTION_OUTPUT = 1;
struct tegra_gpio_platdata {
struct gpio_ctlr_bank *bank;
const char *port_name; /* Name of port, e.g. "B" */
int base_gpio; /* Port number for this port (0, 1,.., n-1) */
};
/* Information about each port at run-time */
struct tegra_port_info {
struct gpio_ctlr_bank *bank;
int base_gpio; /* Port number for this port (0, 1,.., n-1) */
};
/* Return config of pin 'gpio' as GPIO (1) or SFIO (0) */
static int get_config(unsigned gpio)
{
struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
u32 u;
int type;
u = readl(&bank->gpio_config[GPIO_PORT(gpio)]);
type = (u >> GPIO_BIT(gpio)) & 1;
debug("get_config: port = %d, bit = %d is %s\n",
GPIO_FULLPORT(gpio), GPIO_BIT(gpio), type ? "GPIO" : "SFPIO");
return type ? CONFIG_GPIO : CONFIG_SFIO;
}
/* Config pin 'gpio' as GPIO or SFIO, based on 'type' */
static void set_config(unsigned gpio, int type)
{
struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
u32 u;
debug("set_config: port = %d, bit = %d, %s\n",
GPIO_FULLPORT(gpio), GPIO_BIT(gpio), type ? "GPIO" : "SFPIO");
u = readl(&bank->gpio_config[GPIO_PORT(gpio)]);
if (type != CONFIG_SFIO)
u |= 1 << GPIO_BIT(gpio);
else
u &= ~(1 << GPIO_BIT(gpio));
writel(u, &bank->gpio_config[GPIO_PORT(gpio)]);
}
/* Return GPIO pin 'gpio' direction - 0 = input or 1 = output */
static int get_direction(unsigned gpio)
{
struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
u32 u;
int dir;
u = readl(&bank->gpio_dir_out[GPIO_PORT(gpio)]);
dir = (u >> GPIO_BIT(gpio)) & 1;
debug("get_direction: port = %d, bit = %d, %s\n",
GPIO_FULLPORT(gpio), GPIO_BIT(gpio), dir ? "OUT" : "IN");
return dir ? DIRECTION_OUTPUT : DIRECTION_INPUT;
}
/* Config GPIO pin 'gpio' as input or output (OE) as per 'output' */
static void set_direction(unsigned gpio, int output)
{
struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
u32 u;
debug("set_direction: port = %d, bit = %d, %s\n",
GPIO_FULLPORT(gpio), GPIO_BIT(gpio), output ? "OUT" : "IN");
u = readl(&bank->gpio_dir_out[GPIO_PORT(gpio)]);
if (output != DIRECTION_INPUT)
u |= 1 << GPIO_BIT(gpio);
else
u &= ~(1 << GPIO_BIT(gpio));
writel(u, &bank->gpio_dir_out[GPIO_PORT(gpio)]);
}
/* set GPIO pin 'gpio' output bit as 0 or 1 as per 'high' */
static void set_level(unsigned gpio, int high)
{
struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
u32 u;
debug("set_level: port = %d, bit %d == %d\n",
GPIO_FULLPORT(gpio), GPIO_BIT(gpio), high);
u = readl(&bank->gpio_out[GPIO_PORT(gpio)]);
if (high)
u |= 1 << GPIO_BIT(gpio);
else
u &= ~(1 << GPIO_BIT(gpio));
writel(u, &bank->gpio_out[GPIO_PORT(gpio)]);
}
/*
* Generic_GPIO primitives.
*/
/* set GPIO pin 'gpio' as an input */
static int tegra_gpio_direction_input(struct udevice *dev, unsigned offset)
{
struct tegra_port_info *state = dev_get_priv(dev);
/* Configure GPIO direction as input. */
set_direction(state->base_gpio + offset, DIRECTION_INPUT);
/* Enable the pin as a GPIO */
set_config(state->base_gpio + offset, 1);
return 0;
}
/* set GPIO pin 'gpio' as an output, with polarity 'value' */
static int tegra_gpio_direction_output(struct udevice *dev, unsigned offset,
int value)
{
struct tegra_port_info *state = dev_get_priv(dev);
int gpio = state->base_gpio + offset;
/* Configure GPIO output value. */
set_level(gpio, value);
/* Configure GPIO direction as output. */
set_direction(gpio, DIRECTION_OUTPUT);
/* Enable the pin as a GPIO */
set_config(state->base_gpio + offset, 1);
return 0;
}
/* read GPIO IN value of pin 'gpio' */
static int tegra_gpio_get_value(struct udevice *dev, unsigned offset)
{
struct tegra_port_info *state = dev_get_priv(dev);
int gpio = state->base_gpio + offset;
int val;
debug("%s: pin = %d (port %d:bit %d)\n", __func__,
gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio));
if (get_direction(gpio) == DIRECTION_INPUT)
val = readl(&state->bank->gpio_in[GPIO_PORT(gpio)]);
else
val = readl(&state->bank->gpio_out[GPIO_PORT(gpio)]);
return (val >> GPIO_BIT(gpio)) & 1;
}
/* write GPIO OUT value to pin 'gpio' */
static int tegra_gpio_set_value(struct udevice *dev, unsigned offset, int value)
{
struct tegra_port_info *state = dev_get_priv(dev);
int gpio = state->base_gpio + offset;
debug("gpio_set_value: pin = %d (port %d:bit %d), value = %d\n",
gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio), value);
/* Configure GPIO output value. */
set_level(gpio, value);
return 0;
}
void gpio_config_table(const struct tegra_gpio_config *config, int len)
{
int i;
for (i = 0; i < len; i++) {
switch (config[i].init) {
case TEGRA_GPIO_INIT_IN:
set_direction(config[i].gpio, DIRECTION_INPUT);
break;
case TEGRA_GPIO_INIT_OUT0:
set_level(config[i].gpio, 0);
set_direction(config[i].gpio, DIRECTION_OUTPUT);
break;
case TEGRA_GPIO_INIT_OUT1:
set_level(config[i].gpio, 1);
set_direction(config[i].gpio, DIRECTION_OUTPUT);
break;
}
set_config(config[i].gpio, CONFIG_GPIO);
}
}
static int tegra_gpio_get_function(struct udevice *dev, unsigned offset)
{
struct tegra_port_info *state = dev_get_priv(dev);
int gpio = state->base_gpio + offset;
if (!get_config(gpio))
return GPIOF_FUNC;
else if (get_direction(gpio))
return GPIOF_OUTPUT;
else
return GPIOF_INPUT;
}
static int tegra_gpio_xlate(struct udevice *dev, struct gpio_desc *desc,
struct fdtdec_phandle_args *args)
{
int gpio, port, ret;
gpio = args->args[0];
port = gpio / TEGRA_GPIOS_PER_PORT;
ret = device_get_child(dev, port, &desc->dev);
if (ret)
return ret;
desc->offset = gpio % TEGRA_GPIOS_PER_PORT;
desc->flags = args->args[1] & GPIO_ACTIVE_LOW ? GPIOD_ACTIVE_LOW : 0;
return 0;
}
static const struct dm_gpio_ops gpio_tegra_ops = {
.direction_input = tegra_gpio_direction_input,
.direction_output = tegra_gpio_direction_output,
.get_value = tegra_gpio_get_value,
.set_value = tegra_gpio_set_value,
.get_function = tegra_gpio_get_function,
.xlate = tegra_gpio_xlate,
};
/**
* Returns the name of a GPIO port
*
* GPIOs are named A, B, C, ..., Z, AA, BB, CC, ...
*
* @base_port: Base port number (0, 1..n-1)
* @return allocated string containing the name
*/
static char *gpio_port_name(int base_port)
{
char *name, *s;
name = malloc(3);
if (name) {
s = name;
*s++ = 'A' + (base_port % 26);
if (base_port >= 26)
*s++ = *name;
*s = '\0';
}
return name;
}
static const struct udevice_id tegra_gpio_ids[] = {
{ .compatible = "nvidia,tegra30-gpio" },
{ .compatible = "nvidia,tegra20-gpio" },
{ }
};
static int gpio_tegra_probe(struct udevice *dev)
{
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
struct tegra_port_info *priv = dev->priv;
struct tegra_gpio_platdata *plat = dev->platdata;
/* Only child devices have ports */
if (!plat)
return 0;
priv->bank = plat->bank;
priv->base_gpio = plat->base_gpio;
uc_priv->gpio_count = TEGRA_GPIOS_PER_PORT;
uc_priv->bank_name = plat->port_name;
return 0;
}
/**
* We have a top-level GPIO device with no actual GPIOs. It has a child
* device for each Tegra port.
*/
static int gpio_tegra_bind(struct udevice *parent)
{
struct tegra_gpio_platdata *plat = parent->platdata;
struct gpio_ctlr *ctlr;
int bank_count;
int bank;
int ret;
/* If this is a child device, there is nothing to do here */
if (plat)
return 0;
/* TODO(sjg@chromium.org): Remove once SPL supports device tree */
#ifdef CONFIG_SPL_BUILD
ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
bank_count = TEGRA_GPIO_BANKS;
#else
{
int len;
/*
* This driver does not make use of interrupts, other than to figure
* out the number of GPIO banks
*/
if (!fdt_getprop(gd->fdt_blob, parent->of_offset, "interrupts", &len))
return -EINVAL;
bank_count = len / 3 / sizeof(u32);
ctlr = (struct gpio_ctlr *)dev_get_addr(parent);
}
#endif
for (bank = 0; bank < bank_count; bank++) {
int port;
for (port = 0; port < TEGRA_PORTS_PER_BANK; port++) {
struct tegra_gpio_platdata *plat;
struct udevice *dev;
int base_port;
plat = calloc(1, sizeof(*plat));
if (!plat)
return -ENOMEM;
plat->bank = &ctlr->gpio_bank[bank];
base_port = bank * TEGRA_PORTS_PER_BANK + port;
plat->base_gpio = TEGRA_GPIOS_PER_PORT * base_port;
plat->port_name = gpio_port_name(base_port);
ret = device_bind(parent, parent->driver,
plat->port_name, plat, -1, &dev);
if (ret)
return ret;
dev->of_offset = parent->of_offset;
}
}
return 0;
}
U_BOOT_DRIVER(gpio_tegra) = {
.name = "gpio_tegra",
.id = UCLASS_GPIO,
.of_match = tegra_gpio_ids,
.bind = gpio_tegra_bind,
.probe = gpio_tegra_probe,
.priv_auto_alloc_size = sizeof(struct tegra_port_info),
.ops = &gpio_tegra_ops,
.flags = DM_FLAG_PRE_RELOC,
};