power: Add APM X-Gene system reboot driver

Add APM X-Gene SoC system reboot driver. This driver handles only system
reboot. System shutdown is board specific and can be handled by board
driver or GPIO based shutdown driver.

Signed-off-by: Loc Ho <lho@apm.com>
Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Kumar Sankaran <ksankaran@apm.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>

3 files changed, 111 insertions, 0 deletions

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 94122906f9cf..5482280467e5 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -44,3 +44,10 @@ config POWER_RESET_VEXPRESS
         help
           Power off and reset support for the ARM Ltd. Versatile
           Express boards.
+
+config POWER_RESET_XGENE
+        bool "APM SoC X-Gene reset driver"
+        depends on ARM64
+        depends on POWER_RESET
+        help
+          Reboot support for the APM SoC X-Gene Eval boards.
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index b82288e99e92..3e6ed88725ac 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -3,3 +3,4 @@ obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o
 obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
 obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o
 obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o
+obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o
diff --git a/drivers/power/reset/xgene-reboot.c b/drivers/power/reset/xgene-reboot.c
new file mode 100644
index 000000000000..ecd55f81b9d1
--- /dev/null
+++ b/drivers/power/reset/xgene-reboot.c
@@ -0,0 +1,103 @@
+/*
+ * AppliedMicro X-Gene SoC Reboot Driver
+ *
+ * Copyright (c) 2013, Applied Micro Circuits Corporation
+ * Author: Feng Kan <fkan@apm.com>
+ * Author: Loc Ho <lho@apm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ * This driver provides system reboot functionality for APM X-Gene SoC.
+ * For system shutdown, this is board specify. If a board designer
+ * implements GPIO shutdown, use the gpio-poweroff.c driver.
+ */
+#include <linux/io.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/stat.h>
+#include <linux/slab.h>
+#include <asm/system_misc.h>
+
+struct xgene_reboot_context {
+        struct platform_device *pdev;
+        void *csr;
+        u32 mask;
+};
+
+static struct xgene_reboot_context *xgene_restart_ctx;
+
+static void xgene_restart(char str, const char *cmd)
+{
+        struct xgene_reboot_context *ctx = xgene_restart_ctx;
+        unsigned long timeout;
+
+        /* Issue the reboot */
+        if (ctx)
+                writel(ctx->mask, ctx->csr);
+
+        timeout = jiffies + HZ;
+        while (time_before(jiffies, timeout))
+                cpu_relax();
+
+        dev_emerg(&ctx->pdev->dev, "Unable to restart system\n");
+}
+
+static int xgene_reboot_probe(struct platform_device *pdev)
+{
+        struct xgene_reboot_context *ctx;
+
+        ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
+        if (!ctx) {
+                dev_err(&pdev->dev, "out of memory for context\n");
+                return -ENODEV;
+        }
+
+        ctx->csr = of_iomap(pdev->dev.of_node, 0);
+        if (!ctx->csr) {
+                devm_kfree(&pdev->dev, ctx);
+                dev_err(&pdev->dev, "can not map resource\n");
+                return -ENODEV;
+        }
+
+        if (of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask))
+                ctx->mask = 0xFFFFFFFF;
+
+        ctx->pdev = pdev;
+        arm_pm_restart = xgene_restart;
+        xgene_restart_ctx = ctx;
+
+        return 0;
+}
+
+static struct of_device_id xgene_reboot_of_match[] = {
+        { .compatible = "apm,xgene-reboot" },
+        {}
+};
+
+static struct platform_driver xgene_reboot_driver = {
+        .probe = xgene_reboot_probe,
+        .driver = {
+                .name = "xgene-reboot",
+                .of_match_table = xgene_reboot_of_match,
+        },
+};
+
+static int __init xgene_reboot_init(void)
+{
+        return platform_driver_register(&xgene_reboot_driver);
+}
+device_initcall(xgene_reboot_init);