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-rw-r--r--kernel/arch/arm/mach-pxa/reset.c113
1 files changed, 113 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-pxa/reset.c b/kernel/arch/arm/mach-pxa/reset.c
new file mode 100644
index 000000000..263b15249
--- /dev/null
+++ b/kernel/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;
+ }
+}