1 files changed, 115 insertions, 0 deletions
diff --git a/arch/arm/mach-at91/at91sam9_rst.c b/arch/arm/mach-at91/at91sam9_rst.c
new file mode 100644
index 0000000000..d2c008e343
--- /dev/null
+++ b/arch/arm/mach-at91/at91sam9_rst.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 Pengutronix, Ahmad Fatoum <a.fatoum@pengutronix.de>
+ */
+
+#include <common.h>
+#include <init.h>
+#include <io.h>
+#include <restart.h>
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <mach/at91/at91_rstc.h>
+#include <mach/at91/at91sam9260.h>
+#include <reset_source.h>
+
+struct at91sam9x_rst {
+	struct restart_handler restart;
+	void __iomem *base;
+};
+
+static int reasons[] = {
+	RESET_POR, /* GENERAL  Both VDDCORE and VDDBU rising */
+	RESET_WKE, /* WAKEUP   VDDCORE rising */
+	RESET_WDG, /* WATCHDOG Watchdog fault occurred */
+	RESET_RST, /* SOFTWARE Reset required by the software */
+	RESET_EXT, /* USER     NRST pin detected low */
+};
+
+static void at91sam9x_set_reset_reason(struct device *dev,
+				       void __iomem *base)
+{
+	enum reset_src_type type = RESET_UKWN;
+	u32 sr, rsttyp;
+
+	sr = readl(base + AT91_RSTC_SR);
+	rsttyp = FIELD_GET(AT91_RSTC_RSTTYP, sr);
+
+	if (rsttyp < ARRAY_SIZE(reasons))
+		type = reasons[rsttyp];
+
+	dev_info(dev, "reset reason %s (RSTC_SR: 0x%05x)\n",
+		reset_source_to_string(type), sr);
+
+	reset_source_set(type);
+}
+
+static void __noreturn at91sam9x_restart_soc(struct restart_handler *rst)
+{
+	struct at91sam9x_rst *priv = container_of(rst, struct at91sam9x_rst, restart);
+
+	writel(AT91_RSTC_PROCRST
+	       | AT91_RSTC_PERRST
+	       | AT91_RSTC_EXTRST
+	       | AT91_RSTC_KEY,
+	       priv->base + AT91_RSTC_CR);
+
+	hang();
+}
+
+void __noreturn at91sam9_reset(void __iomem *sdram, void __iomem *rstc_cr);
+
+static void __noreturn at91sam9260_restart_soc(struct restart_handler *rst)
+{
+	struct at91sam9x_rst *priv = container_of(rst, struct at91sam9x_rst, restart);
+
+	at91sam9_reset(IOMEM(AT91SAM9260_BASE_SDRAMC),
+		       IOMEM(priv->base + AT91_RSTC_CR));
+}
+
+static int at91sam9x_rst_probe(struct device *dev)
+{
+	struct at91sam9x_rst *priv;
+	struct resource *iores;
+	struct clk *clk;
+
+	iores = dev_request_mem_resource(dev, 0);
+	if (IS_ERR(iores)) {
+		dev_err(dev, "could not get reset memory region\n");
+		return PTR_ERR(iores);
+	}
+
+	priv = xzalloc(sizeof(*priv));
+	priv->base = IOMEM(iores->start);
+
+	clk = clk_get(dev, NULL);
+	if (IS_ERR(clk)) {
+		release_region(iores);
+		free(priv);
+		return PTR_ERR(clk);
+	}
+
+	clk_enable(clk);
+
+	at91sam9x_set_reset_reason(dev, priv->base);
+
+	priv->restart.name = "at91sam9x-rst";
+	priv->restart.restart = device_get_match_data(dev);
+
+	return restart_handler_register(&priv->restart);
+}
+
+static const __maybe_unused struct of_device_id at91sam9x_rst_dt_ids[] = {
+	{ .compatible = "atmel,at91sam9260-rstc", at91sam9260_restart_soc },
+	{ .compatible = "atmel,at91sam9g45-rstc", at91sam9x_restart_soc },
+	{ .compatible = "atmel,sama5d3-rstc", at91sam9x_restart_soc },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, at91sam9x_rst_dt_ids);
+
+static struct driver at91sam9x_rst_driver = {
+	.name		= "at91sam9x-rst",
+	.of_compatible	= DRV_OF_COMPAT(at91sam9x_rst_dt_ids),
+	.probe		= at91sam9x_rst_probe,
+};
+device_platform_driver(at91sam9x_rst_driver);