[U-Boot] [PATCH 2/8] sysreset: add syscon-reboot driver

[Álvaro Fernández Rojas]

Add a new sysreset driver based on linux/drivers/power/reset/syscon-reboot.c,
which provides a generic driver for platforms that only require writing a mask
to a regmap offset.

Signed-off-by: Álvaro Fernández Rojas <noltari at gmail.com>
---
 drivers/sysreset/Kconfig           |  8 +++++
 drivers/sysreset/Makefile          |  1 +
 drivers/sysreset/sysreset_syscon.c | 60 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 69 insertions(+)
 create mode 100644 drivers/sysreset/sysreset_syscon.c

diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
index 05a37b9..0946c9d 100644
--- a/drivers/sysreset/Kconfig
+++ b/drivers/sysreset/Kconfig
@@ -13,4 +13,12 @@ config SYSRESET
 	  to effect a reset. The uclass will try all available drivers when
 	  reset_walk() is called.
 
+config SYSRESET_SYSCON
+	bool "Enable support for mfd syscon reboot driver"
+	depends on SYSRESET
+	select REGMAP
+	select SYSCON
+	help
+	  Description here.
+
 endmenu
diff --git a/drivers/sysreset/Makefile b/drivers/sysreset/Makefile
index 49b8bb6..1205f47 100644
--- a/drivers/sysreset/Makefile
+++ b/drivers/sysreset/Makefile
@@ -18,3 +18,4 @@ obj-$(CONFIG_ARCH_SNAPDRAGON) += sysreset_snapdragon.o
 obj-$(CONFIG_ARCH_STI) += sysreset_sti.o
 obj-$(CONFIG_TARGET_XTFPGA) += sysreset_xtfpga.o
 obj-$(CONFIG_ARCH_ASPEED) += sysreset_ast.o
+obj-$(CONFIG_SYSRESET_SYSCON) += sysreset_syscon.o
diff --git a/drivers/sysreset/sysreset_syscon.c b/drivers/sysreset/sysreset_syscon.c
new file mode 100644
index 0000000..61aeb1d
--- /dev/null
+++ b/drivers/sysreset/sysreset_syscon.c
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2017 Álvaro Fernández Rojas <noltari at gmail.com>
+ *
+ * Derived from linux/drivers/power/reset/syscon-reboot.c:
+ *	Copyright (C) 2013, Applied Micro Circuits Corporation
+ *	Author: Feng Kan <fkan at apm.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <sysreset.h>
+#include <regmap.h>
+#include <syscon.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static int syscon_reboot_request(struct udevice *dev, enum sysreset_t type)
+{
+	struct udevice *syscon;
+	struct regmap *regmap;
+	unsigned int offset, mask;
+	int err;
+
+	err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
+					   "regmap", &syscon);
+	if (err) {
+		error("unable to find syscon device\n");
+		return err;
+	}
+
+	regmap = syscon_get_regmap(syscon);
+	if (!regmap) {
+		error("unable to find regmap\n");
+		return -ENODEV;
+	}
+
+	offset = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev), "offset", 0);
+	mask = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev), "mask", 0);
+
+	return regmap_write(regmap, offset, mask);
+}
+
+static struct sysreset_ops syscon_reboot_ops = {
+	.request	= syscon_reboot_request,
+};
+
+static const struct udevice_id syscon_reboot_ids[] = {
+	{ .compatible = "syscon-reboot" },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(syscon_reboot) = {
+	.name		= "syscon_reboot",
+	.id		= UCLASS_SYSRESET,
+	.of_match	= syscon_reboot_ids,
+	.ops		= &syscon_reboot_ops,
+};
-- 
2.1.4