mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-08-19 00:18:51 +09:00
![Simon Glass](/assets/img/avatar_default.png)
For board IDs a common approach is to set aside several GPIOs for use in determining the board ID. This can provide information about board features and the revision. Add a function that turns a list of GPIOs into an integer by assigning each GPIO to a single bit. Signed-off-by: Simon Glass <sjg@chromium.org>
470 lines
11 KiB
C
470 lines
11 KiB
C
/*
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* Copyright (c) 2013 Google, Inc
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <dm.h>
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#include <errno.h>
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#include <malloc.h>
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#include <asm/gpio.h>
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#include <linux/ctype.h>
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/**
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* gpio_to_device() - Convert global GPIO number to device, number
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* gpio: The numeric representation of the GPIO
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*
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* Convert the GPIO number to an entry in the list of GPIOs
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* or GPIO blocks registered with the GPIO controller. Returns
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* entry on success, NULL on error.
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*/
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static int gpio_to_device(unsigned int gpio, struct udevice **devp,
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unsigned int *offset)
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{
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struct gpio_dev_priv *uc_priv;
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struct udevice *dev;
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int ret;
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for (ret = uclass_first_device(UCLASS_GPIO, &dev);
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dev;
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ret = uclass_next_device(&dev)) {
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uc_priv = dev->uclass_priv;
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if (gpio >= uc_priv->gpio_base &&
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gpio < uc_priv->gpio_base + uc_priv->gpio_count) {
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*devp = dev;
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*offset = gpio - uc_priv->gpio_base;
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return 0;
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}
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}
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/* No such GPIO */
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return ret ? ret : -EINVAL;
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}
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int gpio_lookup_name(const char *name, struct udevice **devp,
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unsigned int *offsetp, unsigned int *gpiop)
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{
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struct gpio_dev_priv *uc_priv = NULL;
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struct udevice *dev;
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ulong offset;
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int numeric;
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int ret;
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if (devp)
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*devp = NULL;
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numeric = isdigit(*name) ? simple_strtoul(name, NULL, 10) : -1;
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for (ret = uclass_first_device(UCLASS_GPIO, &dev);
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dev;
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ret = uclass_next_device(&dev)) {
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int len;
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uc_priv = dev->uclass_priv;
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if (numeric != -1) {
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offset = numeric - uc_priv->gpio_base;
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/* Allow GPIOs to be numbered from 0 */
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if (offset >= 0 && offset < uc_priv->gpio_count)
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break;
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}
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len = uc_priv->bank_name ? strlen(uc_priv->bank_name) : 0;
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if (!strncasecmp(name, uc_priv->bank_name, len)) {
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if (!strict_strtoul(name + len, 10, &offset))
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break;
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}
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}
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if (!dev)
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return ret ? ret : -EINVAL;
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if (devp)
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*devp = dev;
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if (offsetp)
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*offsetp = offset;
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if (gpiop)
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*gpiop = uc_priv->gpio_base + offset;
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return 0;
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}
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/**
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* gpio_request() - [COMPAT] Request GPIO
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* gpio: GPIO number
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* label: Name for the requested GPIO
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*
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* The label is copied and allocated so the caller does not need to keep
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* the pointer around.
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*
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* This function implements the API that's compatible with current
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* GPIO API used in U-Boot. The request is forwarded to particular
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* GPIO driver. Returns 0 on success, negative value on error.
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*/
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int gpio_request(unsigned gpio, const char *label)
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{
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struct gpio_dev_priv *uc_priv;
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unsigned int offset;
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struct udevice *dev;
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char *str;
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int ret;
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ret = gpio_to_device(gpio, &dev, &offset);
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if (ret)
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return ret;
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uc_priv = dev->uclass_priv;
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if (uc_priv->name[offset])
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return -EBUSY;
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str = strdup(label);
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if (!str)
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return -ENOMEM;
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if (gpio_get_ops(dev)->request) {
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ret = gpio_get_ops(dev)->request(dev, offset, label);
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if (ret) {
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free(str);
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return ret;
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}
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}
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uc_priv->name[offset] = str;
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return 0;
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}
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/**
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* gpio_requestf() - [COMPAT] Request GPIO
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* @gpio: GPIO number
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* @fmt: Format string for the requested GPIO
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* @...: Arguments for the printf() format string
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*
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* This function implements the API that's compatible with current
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* GPIO API used in U-Boot. The request is forwarded to particular
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* GPIO driver. Returns 0 on success, negative value on error.
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*/
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int gpio_requestf(unsigned gpio, const char *fmt, ...)
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{
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va_list args;
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char buf[40];
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va_start(args, fmt);
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vscnprintf(buf, sizeof(buf), fmt, args);
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va_end(args);
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return gpio_request(gpio, buf);
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}
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/**
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* gpio_free() - [COMPAT] Relinquish GPIO
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* gpio: GPIO number
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*
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* This function implements the API that's compatible with current
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* GPIO API used in U-Boot. The request is forwarded to particular
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* GPIO driver. Returns 0 on success, negative value on error.
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*/
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int gpio_free(unsigned gpio)
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{
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struct gpio_dev_priv *uc_priv;
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unsigned int offset;
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struct udevice *dev;
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int ret;
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ret = gpio_to_device(gpio, &dev, &offset);
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if (ret)
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return ret;
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uc_priv = dev->uclass_priv;
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if (!uc_priv->name[offset])
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return -ENXIO;
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if (gpio_get_ops(dev)->free) {
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ret = gpio_get_ops(dev)->free(dev, offset);
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if (ret)
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return ret;
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}
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free(uc_priv->name[offset]);
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uc_priv->name[offset] = NULL;
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return 0;
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}
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static int check_reserved(struct udevice *dev, unsigned offset,
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const char *func)
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{
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struct gpio_dev_priv *uc_priv = dev->uclass_priv;
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if (!uc_priv->name[offset]) {
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printf("%s: %s: error: gpio %s%d not reserved\n",
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dev->name, func,
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uc_priv->bank_name ? uc_priv->bank_name : "", offset);
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return -EBUSY;
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}
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return 0;
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}
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/**
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* gpio_direction_input() - [COMPAT] Set GPIO direction to input
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* gpio: GPIO number
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*
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* This function implements the API that's compatible with current
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* GPIO API used in U-Boot. The request is forwarded to particular
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* GPIO driver. Returns 0 on success, negative value on error.
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*/
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int gpio_direction_input(unsigned gpio)
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{
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unsigned int offset;
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struct udevice *dev;
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int ret;
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ret = gpio_to_device(gpio, &dev, &offset);
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if (ret)
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return ret;
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ret = check_reserved(dev, offset, "dir_input");
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return ret ? ret : gpio_get_ops(dev)->direction_input(dev, offset);
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}
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/**
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* gpio_direction_output() - [COMPAT] Set GPIO direction to output and set value
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* gpio: GPIO number
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* value: Logical value to be set on the GPIO pin
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*
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* This function implements the API that's compatible with current
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* GPIO API used in U-Boot. The request is forwarded to particular
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* GPIO driver. Returns 0 on success, negative value on error.
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*/
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int gpio_direction_output(unsigned gpio, int value)
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{
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unsigned int offset;
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struct udevice *dev;
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int ret;
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ret = gpio_to_device(gpio, &dev, &offset);
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if (ret)
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return ret;
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ret = check_reserved(dev, offset, "dir_output");
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return ret ? ret :
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gpio_get_ops(dev)->direction_output(dev, offset, value);
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}
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/**
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* gpio_get_value() - [COMPAT] Sample GPIO pin and return it's value
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* gpio: GPIO number
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*
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* This function implements the API that's compatible with current
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* GPIO API used in U-Boot. The request is forwarded to particular
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* GPIO driver. Returns the value of the GPIO pin, or negative value
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* on error.
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*/
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int gpio_get_value(unsigned gpio)
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{
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unsigned int offset;
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struct udevice *dev;
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int ret;
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ret = gpio_to_device(gpio, &dev, &offset);
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if (ret)
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return ret;
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ret = check_reserved(dev, offset, "get_value");
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return ret ? ret : gpio_get_ops(dev)->get_value(dev, offset);
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}
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/**
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* gpio_set_value() - [COMPAT] Configure logical value on GPIO pin
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* gpio: GPIO number
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* value: Logical value to be set on the GPIO pin.
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*
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* This function implements the API that's compatible with current
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* GPIO API used in U-Boot. The request is forwarded to particular
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* GPIO driver. Returns 0 on success, negative value on error.
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*/
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int gpio_set_value(unsigned gpio, int value)
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{
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unsigned int offset;
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struct udevice *dev;
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int ret;
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ret = gpio_to_device(gpio, &dev, &offset);
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if (ret)
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return ret;
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ret = check_reserved(dev, offset, "set_value");
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return ret ? ret : gpio_get_ops(dev)->set_value(dev, offset, value);
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}
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const char *gpio_get_bank_info(struct udevice *dev, int *bit_count)
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{
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struct gpio_dev_priv *priv;
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/* Must be called on an active device */
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priv = dev->uclass_priv;
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assert(priv);
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*bit_count = priv->gpio_count;
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return priv->bank_name;
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}
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static const char * const gpio_function[GPIOF_COUNT] = {
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"input",
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"output",
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"unused",
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"unknown",
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"func",
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};
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int get_function(struct udevice *dev, int offset, bool skip_unused,
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const char **namep)
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{
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struct gpio_dev_priv *uc_priv = dev->uclass_priv;
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struct dm_gpio_ops *ops = gpio_get_ops(dev);
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BUILD_BUG_ON(GPIOF_COUNT != ARRAY_SIZE(gpio_function));
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if (!device_active(dev))
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return -ENODEV;
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if (offset < 0 || offset >= uc_priv->gpio_count)
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return -EINVAL;
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if (namep)
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*namep = uc_priv->name[offset];
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if (skip_unused && !uc_priv->name[offset])
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return GPIOF_UNUSED;
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if (ops->get_function) {
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int ret;
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ret = ops->get_function(dev, offset);
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if (ret < 0)
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return ret;
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if (ret >= ARRAY_SIZE(gpio_function))
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return -ENODATA;
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return ret;
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}
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return GPIOF_UNKNOWN;
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}
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int gpio_get_function(struct udevice *dev, int offset, const char **namep)
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{
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return get_function(dev, offset, true, namep);
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}
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int gpio_get_raw_function(struct udevice *dev, int offset, const char **namep)
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{
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return get_function(dev, offset, false, namep);
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}
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int gpio_get_status(struct udevice *dev, int offset, char *buf, int buffsize)
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{
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struct dm_gpio_ops *ops = gpio_get_ops(dev);
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struct gpio_dev_priv *priv;
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char *str = buf;
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int func;
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int ret;
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int len;
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BUILD_BUG_ON(GPIOF_COUNT != ARRAY_SIZE(gpio_function));
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*buf = 0;
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priv = dev->uclass_priv;
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ret = gpio_get_raw_function(dev, offset, NULL);
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if (ret < 0)
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return ret;
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func = ret;
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len = snprintf(str, buffsize, "%s%d: %s",
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priv->bank_name ? priv->bank_name : "",
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offset, gpio_function[func]);
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if (func == GPIOF_INPUT || func == GPIOF_OUTPUT ||
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func == GPIOF_UNUSED) {
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const char *label;
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bool used;
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ret = ops->get_value(dev, offset);
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if (ret < 0)
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return ret;
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used = gpio_get_function(dev, offset, &label) != GPIOF_UNUSED;
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snprintf(str + len, buffsize - len, ": %d [%c]%s%s",
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ret,
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used ? 'x' : ' ',
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used ? " " : "",
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label ? label : "");
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}
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return 0;
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}
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/*
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* get a number comprised of multiple GPIO values. gpio_num_array points to
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* the array of gpio pin numbers to scan, terminated by -1.
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*/
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unsigned gpio_get_values_as_int(const int *gpio_num_array)
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{
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int gpio;
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unsigned bitmask = 1;
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unsigned vector = 0;
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while (bitmask &&
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((gpio = *gpio_num_array++) != -1)) {
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if (gpio_get_value(gpio))
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vector |= bitmask;
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bitmask <<= 1;
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}
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return vector;
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}
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/* We need to renumber the GPIOs when any driver is probed/removed */
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static int gpio_renumber(struct udevice *removed_dev)
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{
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struct gpio_dev_priv *uc_priv;
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struct udevice *dev;
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struct uclass *uc;
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unsigned base;
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int ret;
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ret = uclass_get(UCLASS_GPIO, &uc);
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if (ret)
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return ret;
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/* Ensure that we have a base for each bank */
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base = 0;
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uclass_foreach_dev(dev, uc) {
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if (device_active(dev) && dev != removed_dev) {
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uc_priv = dev->uclass_priv;
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uc_priv->gpio_base = base;
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base += uc_priv->gpio_count;
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}
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}
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return 0;
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}
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static int gpio_post_probe(struct udevice *dev)
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{
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struct gpio_dev_priv *uc_priv = dev->uclass_priv;
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uc_priv->name = calloc(uc_priv->gpio_count, sizeof(char *));
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if (!uc_priv->name)
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return -ENOMEM;
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return gpio_renumber(NULL);
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}
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static int gpio_pre_remove(struct udevice *dev)
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{
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struct gpio_dev_priv *uc_priv = dev->uclass_priv;
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int i;
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for (i = 0; i < uc_priv->gpio_count; i++) {
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if (uc_priv->name[i])
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free(uc_priv->name[i]);
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}
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free(uc_priv->name);
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return gpio_renumber(dev);
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}
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UCLASS_DRIVER(gpio) = {
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.id = UCLASS_GPIO,
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.name = "gpio",
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.post_probe = gpio_post_probe,
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.pre_remove = gpio_pre_remove,
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.per_device_auto_alloc_size = sizeof(struct gpio_dev_priv),
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};
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