u-boot/drivers/gpio/tegra_gpio.c
Stephen Warren fe82857c4b gpio: tegra: use named constants
In order to make it clear what the parameters to set_config() and
set_direction() mean, and similarly for the return values from the
respective get_*(), define named constants for these values.

Disassembly shows no diff in the generated code, except that the
order of the code in the branches of tegra_gpio_get_function() gets
modified without affecting behaviour.

Suggested-by: Tom Warren <twarren@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
2015-10-02 11:05:56 -07:00

379 lines
9.4 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));
val = readl(&state->bank->gpio_in[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,
};