u-boot/drivers/gpio/gpio-uclass.c
Simon Glass 962f5caf60 dm: gpio: Add error handling and a function to claim vector GPIOs
gpio_get_values_as_int() should return an error if something goes wrong.
Also provide gpio_claim_vector(), a function to request the GPIOs and set
them to input mode. Otherwise callers have to do this themselves.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
2015-05-13 09:24:06 -07:00

763 lines
17 KiB
C

/*
* Copyright (c) 2013 Google, Inc
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <fdtdec.h>
#include <malloc.h>
#include <asm/gpio.h>
#include <linux/ctype.h>
DECLARE_GLOBAL_DATA_PTR;
/**
* gpio_to_device() - Convert global GPIO number to device, number
*
* Convert the GPIO number to an entry in the list of GPIOs
* or GPIO blocks registered with the GPIO controller. Returns
* entry on success, NULL on error.
*
* @gpio: The numeric representation of the GPIO
* @desc: Returns description (desc->flags will always be 0)
* @return 0 if found, -ENOENT if not found
*/
static int gpio_to_device(unsigned int gpio, struct gpio_desc *desc)
{
struct gpio_dev_priv *uc_priv;
struct udevice *dev;
int ret;
for (ret = uclass_first_device(UCLASS_GPIO, &dev);
dev;
ret = uclass_next_device(&dev)) {
uc_priv = dev_get_uclass_priv(dev);
if (gpio >= uc_priv->gpio_base &&
gpio < uc_priv->gpio_base + uc_priv->gpio_count) {
desc->dev = dev;
desc->offset = gpio - uc_priv->gpio_base;
desc->flags = 0;
return 0;
}
}
/* No such GPIO */
return ret ? ret : -ENOENT;
}
int gpio_lookup_name(const char *name, struct udevice **devp,
unsigned int *offsetp, unsigned int *gpiop)
{
struct gpio_dev_priv *uc_priv = NULL;
struct udevice *dev;
ulong offset;
int numeric;
int ret;
if (devp)
*devp = NULL;
numeric = isdigit(*name) ? simple_strtoul(name, NULL, 10) : -1;
for (ret = uclass_first_device(UCLASS_GPIO, &dev);
dev;
ret = uclass_next_device(&dev)) {
int len;
uc_priv = dev_get_uclass_priv(dev);
if (numeric != -1) {
offset = numeric - uc_priv->gpio_base;
/* Allow GPIOs to be numbered from 0 */
if (offset >= 0 && offset < uc_priv->gpio_count)
break;
}
len = uc_priv->bank_name ? strlen(uc_priv->bank_name) : 0;
if (!strncasecmp(name, uc_priv->bank_name, len)) {
if (!strict_strtoul(name + len, 10, &offset))
break;
}
}
if (!dev)
return ret ? ret : -EINVAL;
if (devp)
*devp = dev;
if (offsetp)
*offsetp = offset;
if (gpiop)
*gpiop = uc_priv->gpio_base + offset;
return 0;
}
static int gpio_find_and_xlate(struct gpio_desc *desc,
struct fdtdec_phandle_args *args)
{
struct dm_gpio_ops *ops = gpio_get_ops(desc->dev);
/* Use the first argument as the offset by default */
if (args->args_count > 0)
desc->offset = args->args[0];
else
desc->offset = -1;
desc->flags = 0;
return ops->xlate ? ops->xlate(desc->dev, desc, args) : 0;
}
static int dm_gpio_request(struct gpio_desc *desc, const char *label)
{
struct udevice *dev = desc->dev;
struct gpio_dev_priv *uc_priv;
char *str;
int ret;
uc_priv = dev_get_uclass_priv(dev);
if (uc_priv->name[desc->offset])
return -EBUSY;
str = strdup(label);
if (!str)
return -ENOMEM;
if (gpio_get_ops(dev)->request) {
ret = gpio_get_ops(dev)->request(dev, desc->offset, label);
if (ret) {
free(str);
return ret;
}
}
uc_priv->name[desc->offset] = str;
return 0;
}
static int dm_gpio_requestf(struct gpio_desc *desc, const char *fmt, ...)
{
va_list args;
char buf[40];
va_start(args, fmt);
vscnprintf(buf, sizeof(buf), fmt, args);
va_end(args);
return dm_gpio_request(desc, buf);
}
/**
* gpio_request() - [COMPAT] Request GPIO
* gpio: GPIO number
* label: Name for the requested GPIO
*
* The label is copied and allocated so the caller does not need to keep
* the pointer around.
*
* This function implements the API that's compatible with current
* GPIO API used in U-Boot. The request is forwarded to particular
* GPIO driver. Returns 0 on success, negative value on error.
*/
int gpio_request(unsigned gpio, const char *label)
{
struct gpio_desc desc;
int ret;
ret = gpio_to_device(gpio, &desc);
if (ret)
return ret;
return dm_gpio_request(&desc, label);
}
/**
* gpio_requestf() - [COMPAT] Request GPIO
* @gpio: GPIO number
* @fmt: Format string for the requested GPIO
* @...: Arguments for the printf() format string
*
* This function implements the API that's compatible with current
* GPIO API used in U-Boot. The request is forwarded to particular
* GPIO driver. Returns 0 on success, negative value on error.
*/
int gpio_requestf(unsigned gpio, const char *fmt, ...)
{
va_list args;
char buf[40];
va_start(args, fmt);
vscnprintf(buf, sizeof(buf), fmt, args);
va_end(args);
return gpio_request(gpio, buf);
}
int _dm_gpio_free(struct udevice *dev, uint offset)
{
struct gpio_dev_priv *uc_priv;
int ret;
uc_priv = dev_get_uclass_priv(dev);
if (!uc_priv->name[offset])
return -ENXIO;
if (gpio_get_ops(dev)->free) {
ret = gpio_get_ops(dev)->free(dev, offset);
if (ret)
return ret;
}
free(uc_priv->name[offset]);
uc_priv->name[offset] = NULL;
return 0;
}
/**
* gpio_free() - [COMPAT] Relinquish GPIO
* gpio: GPIO number
*
* This function implements the API that's compatible with current
* GPIO API used in U-Boot. The request is forwarded to particular
* GPIO driver. Returns 0 on success, negative value on error.
*/
int gpio_free(unsigned gpio)
{
struct gpio_desc desc;
int ret;
ret = gpio_to_device(gpio, &desc);
if (ret)
return ret;
return _dm_gpio_free(desc.dev, desc.offset);
}
static int check_reserved(struct gpio_desc *desc, const char *func)
{
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(desc->dev);
if (!uc_priv->name[desc->offset]) {
printf("%s: %s: error: gpio %s%d not reserved\n",
desc->dev->name, func,
uc_priv->bank_name ? uc_priv->bank_name : "",
desc->offset);
return -EBUSY;
}
return 0;
}
/**
* gpio_direction_input() - [COMPAT] Set GPIO direction to input
* gpio: GPIO number
*
* This function implements the API that's compatible with current
* GPIO API used in U-Boot. The request is forwarded to particular
* GPIO driver. Returns 0 on success, negative value on error.
*/
int gpio_direction_input(unsigned gpio)
{
struct gpio_desc desc;
int ret;
ret = gpio_to_device(gpio, &desc);
if (ret)
return ret;
ret = check_reserved(&desc, "dir_input");
if (ret)
return ret;
return gpio_get_ops(desc.dev)->direction_input(desc.dev, desc.offset);
}
/**
* gpio_direction_output() - [COMPAT] Set GPIO direction to output and set value
* gpio: GPIO number
* value: Logical value to be set on the GPIO pin
*
* This function implements the API that's compatible with current
* GPIO API used in U-Boot. The request is forwarded to particular
* GPIO driver. Returns 0 on success, negative value on error.
*/
int gpio_direction_output(unsigned gpio, int value)
{
struct gpio_desc desc;
int ret;
ret = gpio_to_device(gpio, &desc);
if (ret)
return ret;
ret = check_reserved(&desc, "dir_output");
if (ret)
return ret;
return gpio_get_ops(desc.dev)->direction_output(desc.dev,
desc.offset, value);
}
int dm_gpio_get_value(struct gpio_desc *desc)
{
int value;
int ret;
ret = check_reserved(desc, "get_value");
if (ret)
return ret;
value = gpio_get_ops(desc->dev)->get_value(desc->dev, desc->offset);
return desc->flags & GPIOD_ACTIVE_LOW ? !value : value;
}
int dm_gpio_set_value(struct gpio_desc *desc, int value)
{
int ret;
ret = check_reserved(desc, "set_value");
if (ret)
return ret;
if (desc->flags & GPIOD_ACTIVE_LOW)
value = !value;
gpio_get_ops(desc->dev)->set_value(desc->dev, desc->offset, value);
return 0;
}
int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags)
{
struct udevice *dev = desc->dev;
struct dm_gpio_ops *ops = gpio_get_ops(dev);
int ret;
ret = check_reserved(desc, "set_dir");
if (ret)
return ret;
if (flags & GPIOD_IS_OUT) {
int value = flags & GPIOD_IS_OUT_ACTIVE ? 1 : 0;
if (flags & GPIOD_ACTIVE_LOW)
value = !value;
ret = ops->direction_output(dev, desc->offset, value);
} else if (flags & GPIOD_IS_IN) {
ret = ops->direction_input(dev, desc->offset);
}
if (ret)
return ret;
/*
* Update desc->flags here, so that GPIO_ACTIVE_LOW is honoured in
* futures
*/
desc->flags = flags;
return 0;
}
int dm_gpio_set_dir(struct gpio_desc *desc)
{
return dm_gpio_set_dir_flags(desc, desc->flags);
}
/**
* gpio_get_value() - [COMPAT] Sample GPIO pin and return it's value
* gpio: GPIO number
*
* This function implements the API that's compatible with current
* GPIO API used in U-Boot. The request is forwarded to particular
* GPIO driver. Returns the value of the GPIO pin, or negative value
* on error.
*/
int gpio_get_value(unsigned gpio)
{
int ret;
struct gpio_desc desc;
ret = gpio_to_device(gpio, &desc);
if (ret)
return ret;
return dm_gpio_get_value(&desc);
}
/**
* gpio_set_value() - [COMPAT] Configure logical value on GPIO pin
* gpio: GPIO number
* value: Logical value to be set on the GPIO pin.
*
* This function implements the API that's compatible with current
* GPIO API used in U-Boot. The request is forwarded to particular
* GPIO driver. Returns 0 on success, negative value on error.
*/
int gpio_set_value(unsigned gpio, int value)
{
struct gpio_desc desc;
int ret;
ret = gpio_to_device(gpio, &desc);
if (ret)
return ret;
return dm_gpio_set_value(&desc, value);
}
const char *gpio_get_bank_info(struct udevice *dev, int *bit_count)
{
struct gpio_dev_priv *priv;
/* Must be called on an active device */
priv = dev_get_uclass_priv(dev);
assert(priv);
*bit_count = priv->gpio_count;
return priv->bank_name;
}
static const char * const gpio_function[GPIOF_COUNT] = {
"input",
"output",
"unused",
"unknown",
"func",
};
int get_function(struct udevice *dev, int offset, bool skip_unused,
const char **namep)
{
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
struct dm_gpio_ops *ops = gpio_get_ops(dev);
BUILD_BUG_ON(GPIOF_COUNT != ARRAY_SIZE(gpio_function));
if (!device_active(dev))
return -ENODEV;
if (offset < 0 || offset >= uc_priv->gpio_count)
return -EINVAL;
if (namep)
*namep = uc_priv->name[offset];
if (skip_unused && !uc_priv->name[offset])
return GPIOF_UNUSED;
if (ops->get_function) {
int ret;
ret = ops->get_function(dev, offset);
if (ret < 0)
return ret;
if (ret >= ARRAY_SIZE(gpio_function))
return -ENODATA;
return ret;
}
return GPIOF_UNKNOWN;
}
int gpio_get_function(struct udevice *dev, int offset, const char **namep)
{
return get_function(dev, offset, true, namep);
}
int gpio_get_raw_function(struct udevice *dev, int offset, const char **namep)
{
return get_function(dev, offset, false, namep);
}
int gpio_get_status(struct udevice *dev, int offset, char *buf, int buffsize)
{
struct dm_gpio_ops *ops = gpio_get_ops(dev);
struct gpio_dev_priv *priv;
char *str = buf;
int func;
int ret;
int len;
BUILD_BUG_ON(GPIOF_COUNT != ARRAY_SIZE(gpio_function));
*buf = 0;
priv = dev_get_uclass_priv(dev);
ret = gpio_get_raw_function(dev, offset, NULL);
if (ret < 0)
return ret;
func = ret;
len = snprintf(str, buffsize, "%s%d: %s",
priv->bank_name ? priv->bank_name : "",
offset, gpio_function[func]);
if (func == GPIOF_INPUT || func == GPIOF_OUTPUT ||
func == GPIOF_UNUSED) {
const char *label;
bool used;
ret = ops->get_value(dev, offset);
if (ret < 0)
return ret;
used = gpio_get_function(dev, offset, &label) != GPIOF_UNUSED;
snprintf(str + len, buffsize - len, ": %d [%c]%s%s",
ret,
used ? 'x' : ' ',
used ? " " : "",
label ? label : "");
}
return 0;
}
int gpio_claim_vector(const int *gpio_num_array, const char *fmt)
{
int i, ret;
int gpio;
for (i = 0; i < 32; i++) {
gpio = gpio_num_array[i];
if (gpio == -1)
break;
ret = gpio_requestf(gpio, fmt, i);
if (ret)
goto err;
ret = gpio_direction_input(gpio);
if (ret) {
gpio_free(gpio);
goto err;
}
}
return 0;
err:
for (i--; i >= 0; i--)
gpio_free(gpio_num_array[i]);
return ret;
}
/*
* get a number comprised of multiple GPIO values. gpio_num_array points to
* the array of gpio pin numbers to scan, terminated by -1.
*/
int gpio_get_values_as_int(const int *gpio_list)
{
int gpio;
unsigned bitmask = 1;
unsigned vector = 0;
int ret;
while (bitmask &&
((gpio = *gpio_list++) != -1)) {
ret = gpio_get_value(gpio);
if (ret < 0)
return ret;
else if (ret)
vector |= bitmask;
bitmask <<= 1;
}
return vector;
}
static int _gpio_request_by_name_nodev(const void *blob, int node,
const char *list_name, int index,
struct gpio_desc *desc, int flags,
bool add_index)
{
struct fdtdec_phandle_args args;
int ret;
desc->dev = NULL;
desc->offset = 0;
ret = fdtdec_parse_phandle_with_args(blob, node, list_name,
"#gpio-cells", 0, index, &args);
if (ret) {
debug("%s: fdtdec_parse_phandle_with_args failed\n", __func__);
goto err;
}
ret = uclass_get_device_by_of_offset(UCLASS_GPIO, args.node,
&desc->dev);
if (ret) {
debug("%s: uclass_get_device_by_of_offset failed\n", __func__);
goto err;
}
ret = gpio_find_and_xlate(desc, &args);
if (ret) {
debug("%s: gpio_find_and_xlate failed\n", __func__);
goto err;
}
ret = dm_gpio_requestf(desc, add_index ? "%s.%s%d" : "%s.%s",
fdt_get_name(blob, node, NULL),
list_name, index);
if (ret) {
debug("%s: dm_gpio_requestf failed\n", __func__);
goto err;
}
ret = dm_gpio_set_dir_flags(desc, flags | desc->flags);
if (ret) {
debug("%s: dm_gpio_set_dir failed\n", __func__);
goto err;
}
return 0;
err:
debug("%s: Node '%s', property '%s', failed to request GPIO index %d: %d\n",
__func__, fdt_get_name(blob, node, NULL), list_name, index, ret);
return ret;
}
int gpio_request_by_name_nodev(const void *blob, int node,
const char *list_name, int index,
struct gpio_desc *desc, int flags)
{
return _gpio_request_by_name_nodev(blob, node, list_name, index, desc,
flags, index > 0);
}
int gpio_request_by_name(struct udevice *dev, const char *list_name, int index,
struct gpio_desc *desc, int flags)
{
/*
* This isn't ideal since we don't use dev->name in the debug()
* calls in gpio_request_by_name(), but we can do this until
* gpio_request_by_name_nodev() can be dropped.
*/
return gpio_request_by_name_nodev(gd->fdt_blob, dev->of_offset,
list_name, index, desc, flags);
}
int gpio_request_list_by_name_nodev(const void *blob, int node,
const char *list_name,
struct gpio_desc *desc, int max_count,
int flags)
{
int count;
int ret;
for (count = 0; count < max_count; count++) {
ret = _gpio_request_by_name_nodev(blob, node, list_name, count,
&desc[count], flags, true);
if (ret == -ENOENT)
break;
else if (ret)
goto err;
}
/* We ran out of GPIOs in the list */
return count;
err:
gpio_free_list_nodev(desc, count - 1);
return ret;
}
int gpio_request_list_by_name(struct udevice *dev, const char *list_name,
struct gpio_desc *desc, int max_count,
int flags)
{
/*
* This isn't ideal since we don't use dev->name in the debug()
* calls in gpio_request_by_name(), but we can do this until
* gpio_request_list_by_name_nodev() can be dropped.
*/
return gpio_request_list_by_name_nodev(gd->fdt_blob, dev->of_offset,
list_name, desc, max_count,
flags);
}
int gpio_get_list_count(struct udevice *dev, const char *list_name)
{
int ret;
ret = fdtdec_parse_phandle_with_args(gd->fdt_blob, dev->of_offset,
list_name, "#gpio-cells", 0, -1,
NULL);
if (ret) {
debug("%s: Node '%s', property '%s', GPIO count failed: %d\n",
__func__, dev->name, list_name, ret);
}
return ret;
}
int dm_gpio_free(struct udevice *dev, struct gpio_desc *desc)
{
/* For now, we don't do any checking of dev */
return _dm_gpio_free(desc->dev, desc->offset);
}
int gpio_free_list(struct udevice *dev, struct gpio_desc *desc, int count)
{
int i;
/* For now, we don't do any checking of dev */
for (i = 0; i < count; i++)
dm_gpio_free(dev, &desc[i]);
return 0;
}
int gpio_free_list_nodev(struct gpio_desc *desc, int count)
{
return gpio_free_list(NULL, desc, count);
}
/* We need to renumber the GPIOs when any driver is probed/removed */
static int gpio_renumber(struct udevice *removed_dev)
{
struct gpio_dev_priv *uc_priv;
struct udevice *dev;
struct uclass *uc;
unsigned base;
int ret;
ret = uclass_get(UCLASS_GPIO, &uc);
if (ret)
return ret;
/* Ensure that we have a base for each bank */
base = 0;
uclass_foreach_dev(dev, uc) {
if (device_active(dev) && dev != removed_dev) {
uc_priv = dev_get_uclass_priv(dev);
uc_priv->gpio_base = base;
base += uc_priv->gpio_count;
}
}
return 0;
}
int gpio_get_number(struct gpio_desc *desc)
{
struct udevice *dev = desc->dev;
struct gpio_dev_priv *uc_priv;
if (!dev)
return -1;
uc_priv = dev->uclass_priv;
return uc_priv->gpio_base + desc->offset;
}
static int gpio_post_probe(struct udevice *dev)
{
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
uc_priv->name = calloc(uc_priv->gpio_count, sizeof(char *));
if (!uc_priv->name)
return -ENOMEM;
return gpio_renumber(NULL);
}
static int gpio_pre_remove(struct udevice *dev)
{
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
int i;
for (i = 0; i < uc_priv->gpio_count; i++) {
if (uc_priv->name[i])
free(uc_priv->name[i]);
}
free(uc_priv->name);
return gpio_renumber(dev);
}
UCLASS_DRIVER(gpio) = {
.id = UCLASS_GPIO,
.name = "gpio",
.post_probe = gpio_post_probe,
.pre_remove = gpio_pre_remove,
.per_device_auto_alloc_size = sizeof(struct gpio_dev_priv),
};