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authorAnders Berg <anders.berg@lsi.com>2014-05-23 13:08:38 +0400
committerArnd Bergmann <arnd@arndb.de>2014-05-23 20:18:45 +0400
commit4a315e3457e008e0570c392822ae98cdf7761227 (patch)
tree6e602fd67651e433571db36df7c2c86a1ffbfd85 /drivers/power/reset/axxia-reset.c
parent2baa4559ab7c934b3b6ced33e6e369081f27e7df (diff)
downloadlinux-4a315e3457e008e0570c392822ae98cdf7761227.tar.xz
power: reset: Add Axxia system reset driver
Add Axxia (AXM55xx) SoC system reset driver. This driver handles only system reboot (and not power-off). Signed-off-by: Anders Berg <anders.berg@lsi.com> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'drivers/power/reset/axxia-reset.c')
-rw-r--r--drivers/power/reset/axxia-reset.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/drivers/power/reset/axxia-reset.c b/drivers/power/reset/axxia-reset.c
new file mode 100644
index 000000000000..3b1f8d601784
--- /dev/null
+++ b/drivers/power/reset/axxia-reset.c
@@ -0,0 +1,88 @@
+/*
+ * Reset driver for Axxia devices
+ *
+ * Copyright (C) 2014 LSI
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+
+#include <asm/system_misc.h>
+
+
+#define SC_CRIT_WRITE_KEY 0x1000
+#define SC_LATCH_ON_RESET 0x1004
+#define SC_RESET_CONTROL 0x1008
+#define RSTCTL_RST_ZERO (1<<3)
+#define RSTCTL_RST_FAB (1<<2)
+#define RSTCTL_RST_CHIP (1<<1)
+#define RSTCTL_RST_SYS (1<<0)
+#define SC_EFUSE_INT_STATUS 0x180c
+#define EFUSE_READ_DONE (1<<31)
+
+static struct regmap *syscon;
+
+static void do_axxia_restart(enum reboot_mode reboot_mode, const char *cmd)
+{
+ /* Access Key (0xab) */
+ regmap_write(syscon, SC_CRIT_WRITE_KEY, 0xab);
+ /* Select internal boot from 0xffff0000 */
+ regmap_write(syscon, SC_LATCH_ON_RESET, 0x00000040);
+ /* Assert ResetReadDone (to avoid hanging in boot ROM) */
+ regmap_write(syscon, SC_EFUSE_INT_STATUS, EFUSE_READ_DONE);
+ /* Assert chip reset */
+ regmap_update_bits(syscon, SC_RESET_CONTROL,
+ RSTCTL_RST_CHIP, RSTCTL_RST_CHIP);
+}
+
+static int axxia_reset_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+
+ syscon = syscon_regmap_lookup_by_phandle(dev->of_node, "syscon");
+ if (IS_ERR(syscon)) {
+ pr_err("%s: syscon lookup failed\n", dev->of_node->name);
+ return PTR_ERR(syscon);
+ }
+
+ arm_pm_restart = do_axxia_restart;
+
+ return 0;
+}
+
+static const struct of_device_id of_axxia_reset_match[] = {
+ { .compatible = "lsi,axm55xx-reset", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, of_axxia_reset_match);
+
+static struct platform_driver axxia_reset_driver = {
+ .probe = axxia_reset_probe,
+ .driver = {
+ .name = "axxia-reset",
+ .of_match_table = of_match_ptr(of_axxia_reset_match),
+ },
+};
+
+static int __init axxia_reset_init(void)
+{
+ return platform_driver_register(&axxia_reset_driver);
+}
+device_initcall(axxia_reset_init);