v4.19.13 snapshot.
diff --git a/drivers/power/reset/at91-poweroff.c b/drivers/power/reset/at91-poweroff.c
new file mode 100644
index 0000000..fb2fc8f
--- /dev/null
+++ b/drivers/power/reset/at91-poweroff.c
@@ -0,0 +1,237 @@
+/*
+ * Atmel AT91 SAM9 SoCs reset code
+ *
+ * Copyright (C) 2007 Atmel Corporation.
+ * Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
+ * Copyright (C) 2014 Free Electrons
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+
+#include <soc/at91/at91sam9_ddrsdr.h>
+
+#define AT91_SHDW_CR	0x00		/* Shut Down Control Register */
+#define AT91_SHDW_SHDW		BIT(0)			/* Shut Down command */
+#define AT91_SHDW_KEY		(0xa5 << 24)		/* KEY Password */
+
+#define AT91_SHDW_MR	0x04		/* Shut Down Mode Register */
+#define AT91_SHDW_WKMODE0	GENMASK(2, 0)		/* Wake-up 0 Mode Selection */
+#define AT91_SHDW_CPTWK0_MAX	0xf			/* Maximum Counter On Wake Up 0 */
+#define AT91_SHDW_CPTWK0	(AT91_SHDW_CPTWK0_MAX << 4) /* Counter On Wake Up 0 */
+#define AT91_SHDW_CPTWK0_(x)	((x) << 4)
+#define AT91_SHDW_RTTWKEN	BIT(16)			/* Real Time Timer Wake-up Enable */
+#define AT91_SHDW_RTCWKEN	BIT(17)			/* Real Time Clock Wake-up Enable */
+
+#define AT91_SHDW_SR	0x08		/* Shut Down Status Register */
+#define AT91_SHDW_WAKEUP0	BIT(0)			/* Wake-up 0 Status */
+#define AT91_SHDW_RTTWK		BIT(16)			/* Real-time Timer Wake-up */
+#define AT91_SHDW_RTCWK		BIT(17)			/* Real-time Clock Wake-up [SAM9RL] */
+
+enum wakeup_type {
+	AT91_SHDW_WKMODE0_NONE		= 0,
+	AT91_SHDW_WKMODE0_HIGH		= 1,
+	AT91_SHDW_WKMODE0_LOW		= 2,
+	AT91_SHDW_WKMODE0_ANYLEVEL	= 3,
+};
+
+static const char *shdwc_wakeup_modes[] = {
+	[AT91_SHDW_WKMODE0_NONE]	= "none",
+	[AT91_SHDW_WKMODE0_HIGH]	= "high",
+	[AT91_SHDW_WKMODE0_LOW]		= "low",
+	[AT91_SHDW_WKMODE0_ANYLEVEL]	= "any",
+};
+
+static void __iomem *at91_shdwc_base;
+static struct clk *sclk;
+static void __iomem *mpddrc_base;
+
+static void __init at91_wakeup_status(struct platform_device *pdev)
+{
+	const char *reason;
+	u32 reg = readl(at91_shdwc_base + AT91_SHDW_SR);
+
+	/* Simple power-on, just bail out */
+	if (!reg)
+		return;
+
+	if (reg & AT91_SHDW_RTTWK)
+		reason = "RTT";
+	else if (reg & AT91_SHDW_RTCWK)
+		reason = "RTC";
+	else
+		reason = "unknown";
+
+	dev_info(&pdev->dev, "Wake-Up source: %s\n", reason);
+}
+
+static void at91_poweroff(void)
+{
+	writel(AT91_SHDW_KEY | AT91_SHDW_SHDW, at91_shdwc_base + AT91_SHDW_CR);
+}
+
+static void at91_lpddr_poweroff(void)
+{
+	asm volatile(
+		/* Align to cache lines */
+		".balign 32\n\t"
+
+		/* Ensure AT91_SHDW_CR is in the TLB by reading it */
+		"	ldr	r6, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"
+
+		/* Power down SDRAM0 */
+		"	str	%1, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t"
+		/* Shutdown CPU */
+		"	str	%3, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"
+
+		"	b	.\n\t"
+		:
+		: "r" (mpddrc_base),
+		  "r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF),
+		  "r" (at91_shdwc_base),
+		  "r" cpu_to_le32(AT91_SHDW_KEY | AT91_SHDW_SHDW)
+		: "r6");
+}
+
+static int at91_poweroff_get_wakeup_mode(struct device_node *np)
+{
+	const char *pm;
+	unsigned int i;
+	int err;
+
+	err = of_property_read_string(np, "atmel,wakeup-mode", &pm);
+	if (err < 0)
+		return AT91_SHDW_WKMODE0_ANYLEVEL;
+
+	for (i = 0; i < ARRAY_SIZE(shdwc_wakeup_modes); i++)
+		if (!strcasecmp(pm, shdwc_wakeup_modes[i]))
+			return i;
+
+	return -ENODEV;
+}
+
+static void at91_poweroff_dt_set_wakeup_mode(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int wakeup_mode;
+	u32 mode = 0, tmp;
+
+	wakeup_mode = at91_poweroff_get_wakeup_mode(np);
+	if (wakeup_mode < 0) {
+		dev_warn(&pdev->dev, "shdwc unknown wakeup mode\n");
+		return;
+	}
+
+	if (!of_property_read_u32(np, "atmel,wakeup-counter", &tmp)) {
+		if (tmp > AT91_SHDW_CPTWK0_MAX) {
+			dev_warn(&pdev->dev,
+				 "shdwc wakeup counter 0x%x > 0x%x reduce it to 0x%x\n",
+				 tmp, AT91_SHDW_CPTWK0_MAX, AT91_SHDW_CPTWK0_MAX);
+			tmp = AT91_SHDW_CPTWK0_MAX;
+		}
+		mode |= AT91_SHDW_CPTWK0_(tmp);
+	}
+
+	if (of_property_read_bool(np, "atmel,wakeup-rtc-timer"))
+			mode |= AT91_SHDW_RTCWKEN;
+
+	if (of_property_read_bool(np, "atmel,wakeup-rtt-timer"))
+			mode |= AT91_SHDW_RTTWKEN;
+
+	writel(wakeup_mode | mode, at91_shdwc_base + AT91_SHDW_MR);
+}
+
+static int __init at91_poweroff_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct device_node *np;
+	u32 ddr_type;
+	int ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	at91_shdwc_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(at91_shdwc_base))
+		return PTR_ERR(at91_shdwc_base);
+
+	sclk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(sclk))
+		return PTR_ERR(sclk);
+
+	ret = clk_prepare_enable(sclk);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not enable slow clock\n");
+		return ret;
+	}
+
+	at91_wakeup_status(pdev);
+
+	if (pdev->dev.of_node)
+		at91_poweroff_dt_set_wakeup_mode(pdev);
+
+	pm_power_off = at91_poweroff;
+
+	np = of_find_compatible_node(NULL, NULL, "atmel,sama5d3-ddramc");
+	if (!np)
+		return 0;
+
+	mpddrc_base = of_iomap(np, 0);
+	of_node_put(np);
+
+	if (!mpddrc_base)
+		return 0;
+
+	ddr_type = readl(mpddrc_base + AT91_DDRSDRC_MDR) & AT91_DDRSDRC_MD;
+	if ((ddr_type == AT91_DDRSDRC_MD_LPDDR2) ||
+	    (ddr_type == AT91_DDRSDRC_MD_LPDDR3))
+		pm_power_off = at91_lpddr_poweroff;
+	else
+		iounmap(mpddrc_base);
+
+	return 0;
+}
+
+static int __exit at91_poweroff_remove(struct platform_device *pdev)
+{
+	if (pm_power_off == at91_poweroff ||
+	    pm_power_off == at91_lpddr_poweroff)
+		pm_power_off = NULL;
+
+	clk_disable_unprepare(sclk);
+
+	return 0;
+}
+
+static const struct of_device_id at91_ramc_of_match[] = {
+	{ .compatible = "atmel,sama5d3-ddramc", },
+	{ /* sentinel */ }
+};
+
+static const struct of_device_id at91_poweroff_of_match[] = {
+	{ .compatible = "atmel,at91sam9260-shdwc", },
+	{ .compatible = "atmel,at91sam9rl-shdwc", },
+	{ .compatible = "atmel,at91sam9x5-shdwc", },
+	{ /*sentinel*/ }
+};
+MODULE_DEVICE_TABLE(of, at91_poweroff_of_match);
+
+static struct platform_driver at91_poweroff_driver = {
+	.remove = __exit_p(at91_poweroff_remove),
+	.driver = {
+		.name = "at91-poweroff",
+		.of_match_table = at91_poweroff_of_match,
+	},
+};
+module_platform_driver_probe(at91_poweroff_driver, at91_poweroff_probe);
+
+MODULE_AUTHOR("Atmel Corporation");
+MODULE_DESCRIPTION("Shutdown driver for Atmel SoCs");
+MODULE_LICENSE("GPL v2");