108 lines
2.0 KiB
C
108 lines
2.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/delay.h>
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#include <linux/gpio.h>
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#include <linux/io.h>
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#include <asm/proc-fns.h>
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#include <asm/system_misc.h>
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#include "regs-ost.h"
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#include "reset.h"
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#include "smemc.h"
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#include "generic.h"
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static void do_hw_reset(void);
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static int reset_gpio = -1;
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int init_gpio_reset(int gpio, int output, int level)
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{
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int rc;
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rc = gpio_request(gpio, "reset generator");
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if (rc) {
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printk(KERN_ERR "Can't request reset_gpio\n");
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goto out;
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}
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if (output)
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rc = gpio_direction_output(gpio, level);
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else
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rc = gpio_direction_input(gpio);
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if (rc) {
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printk(KERN_ERR "Can't configure reset_gpio\n");
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gpio_free(gpio);
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goto out;
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}
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out:
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if (!rc)
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reset_gpio = gpio;
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return rc;
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}
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/*
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* Trigger GPIO reset.
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* This covers various types of logic connecting gpio pin
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* to RESET pins (nRESET or GPIO_RESET):
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*/
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static void do_gpio_reset(void)
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{
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BUG_ON(reset_gpio == -1);
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/* drive it low */
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gpio_direction_output(reset_gpio, 0);
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mdelay(2);
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/* rising edge or drive high */
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gpio_set_value(reset_gpio, 1);
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mdelay(2);
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/* falling edge */
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gpio_set_value(reset_gpio, 0);
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/* give it some time */
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mdelay(10);
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WARN_ON(1);
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/* fallback */
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do_hw_reset();
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}
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static void do_hw_reset(void)
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{
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/* Initialize the watchdog and let it fire */
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writel_relaxed(OWER_WME, OWER);
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writel_relaxed(OSSR_M3, OSSR);
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/* ... in 100 ms */
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writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3);
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/*
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* SDRAM hangs on watchdog reset on Marvell PXA270 (erratum 71)
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* we put SDRAM into self-refresh to prevent that
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*/
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while (1)
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writel_relaxed(MDREFR_SLFRSH, MDREFR);
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}
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void pxa_restart(enum reboot_mode mode, const char *cmd)
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{
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local_irq_disable();
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local_fiq_disable();
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clear_reset_status(RESET_STATUS_ALL);
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switch (mode) {
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case REBOOT_SOFT:
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/* Jump into ROM at address 0 */
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soft_restart(0);
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break;
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case REBOOT_GPIO:
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do_gpio_reset();
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break;
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case REBOOT_HARD:
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default:
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do_hw_reset();
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break;
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}
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}
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