From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 arch/arm/mach-pxa/reset.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 113 insertions(+)
 create mode 100644 arch/arm/mach-pxa/reset.c

(limited to 'arch/arm/mach-pxa/reset.c')

diff --git a/arch/arm/mach-pxa/reset.c b/arch/arm/mach-pxa/reset.c
new file mode 100644
index 000000000..263b15249
--- /dev/null
+++ b/arch/arm/mach-pxa/reset.c
@@ -0,0 +1,113 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/io.h>
+#include <asm/proc-fns.h>
+#include <asm/system_misc.h>
+
+#include <mach/regs-ost.h>
+#include <mach/reset.h>
+#include <mach/smemc.h>
+
+unsigned int reset_status;
+EXPORT_SYMBOL(reset_status);
+
+static void do_hw_reset(void);
+
+static int reset_gpio = -1;
+
+int init_gpio_reset(int gpio, int output, int level)
+{
+	int rc;
+
+	rc = gpio_request(gpio, "reset generator");
+	if (rc) {
+		printk(KERN_ERR "Can't request reset_gpio\n");
+		goto out;
+	}
+
+	if (output)
+		rc = gpio_direction_output(gpio, level);
+	else
+		rc = gpio_direction_input(gpio);
+	if (rc) {
+		printk(KERN_ERR "Can't configure reset_gpio\n");
+		gpio_free(gpio);
+		goto out;
+	}
+
+out:
+	if (!rc)
+		reset_gpio = gpio;
+
+	return rc;
+}
+
+/*
+ * Trigger GPIO reset.
+ * This covers various types of logic connecting gpio pin
+ * to RESET pins (nRESET or GPIO_RESET):
+ */
+static void do_gpio_reset(void)
+{
+	BUG_ON(reset_gpio == -1);
+
+	/* drive it low */
+	gpio_direction_output(reset_gpio, 0);
+	mdelay(2);
+	/* rising edge or drive high */
+	gpio_set_value(reset_gpio, 1);
+	mdelay(2);
+	/* falling edge */
+	gpio_set_value(reset_gpio, 0);
+
+	/* give it some time */
+	mdelay(10);
+
+	WARN_ON(1);
+	/* fallback */
+	do_hw_reset();
+}
+
+static void do_hw_reset(void)
+{
+	/* Initialize the watchdog and let it fire */
+	writel_relaxed(OWER_WME, OWER);
+	writel_relaxed(OSSR_M3, OSSR);
+	/* ... in 100 ms */
+	writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3);
+	/*
+	 * SDRAM hangs on watchdog reset on Marvell PXA270 (erratum 71)
+	 * we put SDRAM into self-refresh to prevent that
+	 */
+	while (1)
+		writel_relaxed(MDREFR_SLFRSH, MDREFR);
+}
+
+void pxa_restart(enum reboot_mode mode, const char *cmd)
+{
+	local_irq_disable();
+	local_fiq_disable();
+
+	clear_reset_status(RESET_STATUS_ALL);
+
+	switch (mode) {
+	case REBOOT_SOFT:
+		/* Jump into ROM at address 0 */
+		soft_restart(0);
+		break;
+	case REBOOT_GPIO:
+		do_gpio_reset();
+		break;
+	case REBOOT_HARD:
+	default:
+		do_hw_reset();
+		break;
+	}
+}
-- 
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