1 files changed, 131 insertions, 0 deletions
diff --git a/drivers/power/reset/ocelot-reset.c b/drivers/power/reset/ocelot-reset.c
new file mode 100644
index 000000000..f74e1dbb4
--- /dev/null
+++ b/drivers/power/reset/ocelot-reset.c
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * Microsemi MIPS SoC reset driver
+ *
+ * License: Dual MIT/GPL
+ * Copyright (c) 2017 Microsemi Corporation
+ */
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/notifier.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+
+struct reset_props {
+	const char *syscon;
+	u32 protect_reg;
+	u32 vcore_protect;
+	u32 if_si_owner_bit;
+};
+
+struct ocelot_reset_context {
+	void __iomem *base;
+	struct regmap *cpu_ctrl;
+	const struct reset_props *props;
+	struct notifier_block restart_handler;
+};
+
+#define SOFT_CHIP_RST BIT(0)
+
+#define ICPU_CFG_CPU_SYSTEM_CTRL_GENERAL_CTRL	0x24
+#define IF_SI_OWNER_MASK			GENMASK(1, 0)
+#define IF_SI_OWNER_SISL			0
+#define IF_SI_OWNER_SIBM			1
+#define IF_SI_OWNER_SIMC			2
+
+static int ocelot_restart_handle(struct notifier_block *this,
+				 unsigned long mode, void *cmd)
+{
+	struct ocelot_reset_context *ctx = container_of(this, struct
+							ocelot_reset_context,
+							restart_handler);
+	u32 if_si_owner_bit = ctx->props->if_si_owner_bit;
+
+	/* Make sure the core is not protected from reset */
+	regmap_update_bits(ctx->cpu_ctrl, ctx->props->protect_reg,
+			   ctx->props->vcore_protect, 0);
+
+	/* Make the SI back to boot mode */
+	regmap_update_bits(ctx->cpu_ctrl, ICPU_CFG_CPU_SYSTEM_CTRL_GENERAL_CTRL,
+			   IF_SI_OWNER_MASK << if_si_owner_bit,
+			   IF_SI_OWNER_SIBM << if_si_owner_bit);
+
+	pr_emerg("Resetting SoC\n");
+
+	writel(SOFT_CHIP_RST, ctx->base);
+
+	pr_emerg("Unable to restart system\n");
+	return NOTIFY_DONE;
+}
+
+static int ocelot_reset_probe(struct platform_device *pdev)
+{
+	struct ocelot_reset_context *ctx;
+	struct resource *res;
+
+	struct device *dev = &pdev->dev;
+	int err;
+
+	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ctx->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(ctx->base))
+		return PTR_ERR(ctx->base);
+
+	ctx->props = device_get_match_data(dev);
+
+	ctx->cpu_ctrl = syscon_regmap_lookup_by_compatible(ctx->props->syscon);
+	if (IS_ERR(ctx->cpu_ctrl)) {
+		dev_err(dev, "No syscon map: %s\n", ctx->props->syscon);
+		return PTR_ERR(ctx->cpu_ctrl);
+	}
+
+	ctx->restart_handler.notifier_call = ocelot_restart_handle;
+	ctx->restart_handler.priority = 192;
+	err = register_restart_handler(&ctx->restart_handler);
+	if (err)
+		dev_err(dev, "can't register restart notifier (err=%d)\n", err);
+
+	return err;
+}
+
+static const struct reset_props reset_props_ocelot = {
+	.syscon		 = "mscc,ocelot-cpu-syscon",
+	.protect_reg     = 0x20,
+	.vcore_protect   = BIT(2),
+	.if_si_owner_bit = 4,
+};
+
+static const struct reset_props reset_props_sparx5 = {
+	.syscon		 = "microchip,sparx5-cpu-syscon",
+	.protect_reg     = 0x84,
+	.vcore_protect   = BIT(10),
+	.if_si_owner_bit = 6,
+};
+
+static const struct of_device_id ocelot_reset_of_match[] = {
+	{
+		.compatible = "mscc,ocelot-chip-reset",
+		.data = &reset_props_ocelot
+	}, {
+		.compatible = "microchip,sparx5-chip-reset",
+		.data = &reset_props_sparx5
+	},
+	{ /*sentinel*/ }
+};
+
+static struct platform_driver ocelot_reset_driver = {
+	.probe = ocelot_reset_probe,
+	.driver = {
+		.name = "ocelot-chip-reset",
+		.of_match_table = ocelot_reset_of_match,
+	},
+};
+builtin_platform_driver(ocelot_reset_driver);