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https://github.com/torvalds/linux
synced 2024-11-05 18:23:50 +00:00
67bf876654
Till this patch reset always perform writen to 1. Now we can use negative logic and perform reset write to 0. It is opposite level than is currently read from that pin Signed-off-by: Michal Simek <monstr@monstr.eu>
140 lines
2.8 KiB
C
140 lines
2.8 KiB
C
/*
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* Copyright (C) 2009 Michal Simek <monstr@monstr.eu>
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* Copyright (C) 2009 PetaLogix
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/init.h>
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#include <linux/of_platform.h>
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#include <asm/prom.h>
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/* Trigger specific functions */
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#ifdef CONFIG_GPIOLIB
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#include <linux/of_gpio.h>
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static int handle; /* reset pin handle */
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static unsigned int reset_val;
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static int of_reset_gpio_handle(void)
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{
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int ret; /* variable which stored handle reset gpio pin */
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struct device_node *root; /* root node */
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struct device_node *gpio; /* gpio node */
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struct of_gpio_chip *of_gc = NULL;
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enum of_gpio_flags flags ;
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const void *gpio_spec;
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/* find out root node */
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root = of_find_node_by_path("/");
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/* give me handle for gpio node to be possible allocate pin */
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ret = of_parse_phandles_with_args(root, "hard-reset-gpios",
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"#gpio-cells", 0, &gpio, &gpio_spec);
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if (ret) {
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pr_debug("%s: can't parse gpios property\n", __func__);
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goto err0;
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}
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of_gc = gpio->data;
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if (!of_gc) {
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pr_debug("%s: gpio controller %s isn't registered\n",
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root->full_name, gpio->full_name);
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ret = -ENODEV;
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goto err1;
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}
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ret = of_gc->xlate(of_gc, root, gpio_spec, &flags);
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if (ret < 0)
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goto err1;
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ret += of_gc->gc.base;
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err1:
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of_node_put(gpio);
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err0:
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pr_debug("%s exited with status %d\n", __func__, ret);
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return ret;
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}
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void of_platform_reset_gpio_probe(void)
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{
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int ret;
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handle = of_reset_gpio_handle();
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if (!gpio_is_valid(handle)) {
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printk(KERN_INFO "Skipping unavailable RESET gpio %d (%s)\n",
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handle, "reset");
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}
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ret = gpio_request(handle, "reset");
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if (ret < 0) {
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printk(KERN_INFO "GPIO pin is already allocated\n");
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return;
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}
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/* get current setup value */
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reset_val = gpio_get_value(handle);
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/* FIXME maybe worth to perform any action */
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pr_debug("Reset: Gpio output state: 0x%x\n", reset_val);
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/* Setup GPIO as output */
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ret = gpio_direction_output(handle, 0);
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if (ret < 0)
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goto err;
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/* Setup output direction */
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gpio_set_value(handle, 0);
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printk(KERN_INFO "RESET: Registered gpio device: %d, current val: %d\n",
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handle, reset_val);
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return;
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err:
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gpio_free(handle);
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return;
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}
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static void gpio_system_reset(void)
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{
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gpio_set_value(handle, 1 - reset_val);
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}
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#else
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#define gpio_system_reset() do {} while (0)
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void of_platform_reset_gpio_probe(void)
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{
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return;
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}
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#endif
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void machine_restart(char *cmd)
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{
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printk(KERN_NOTICE "Machine restart...\n");
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gpio_system_reset();
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dump_stack();
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while (1)
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;
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}
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void machine_shutdown(void)
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{
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printk(KERN_NOTICE "Machine shutdown...\n");
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while (1)
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;
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}
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void machine_halt(void)
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{
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printk(KERN_NOTICE "Machine halt...\n");
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while (1)
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;
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}
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void machine_power_off(void)
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{
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printk(KERN_NOTICE "Machine power off...\n");
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while (1)
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;
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}
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