File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/mips/lantiq/xway/reset.c b/arch/mips/lantiq/xway/reset.c
new file mode 100644
index 0000000..bc29bb3
--- /dev/null
+++ b/arch/mips/lantiq/xway/reset.c
@@ -0,0 +1,387 @@
+/*
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ *  Copyright (C) 2010 John Crispin <blogic@openwrt.org>
+ *  Copyright (C) 2013-2015 Lantiq Beteiligungs-GmbH & Co.KG
+ */
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/pm.h>
+#include <linux/export.h>
+#include <linux/delay.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/reset-controller.h>
+
+#include <asm/reboot.h>
+
+#include <lantiq_soc.h>
+
+#include "../prom.h"
+
+/* reset request register */
+#define RCU_RST_REQ		0x0010
+/* reset status register */
+#define RCU_RST_STAT		0x0014
+/* vr9 gphy registers */
+#define RCU_GFS_ADD0_XRX200	0x0020
+#define RCU_GFS_ADD1_XRX200	0x0068
+/* xRX300 gphy registers */
+#define RCU_GFS_ADD0_XRX300	0x0020
+#define RCU_GFS_ADD1_XRX300	0x0058
+#define RCU_GFS_ADD2_XRX300	0x00AC
+/* xRX330 gphy registers */
+#define RCU_GFS_ADD0_XRX330	0x0020
+#define RCU_GFS_ADD1_XRX330	0x0058
+#define RCU_GFS_ADD2_XRX330	0x00AC
+#define RCU_GFS_ADD3_XRX330	0x0264
+
+/* xbar BE flag */
+#define RCU_AHB_ENDIAN          0x004C
+#define RCU_VR9_BE_AHB1S        0x00000008
+
+/* reboot bit */
+#define RCU_RD_GPHY0_XRX200	BIT(31)
+#define RCU_RD_SRST		BIT(30)
+#define RCU_RD_GPHY1_XRX200	BIT(29)
+/* xRX300 bits */
+#define RCU_RD_GPHY0_XRX300	BIT(31)
+#define RCU_RD_GPHY1_XRX300	BIT(29)
+#define RCU_RD_GPHY2_XRX300	BIT(28)
+/* xRX330 bits */
+#define RCU_RD_GPHY0_XRX330	BIT(31)
+#define RCU_RD_GPHY1_XRX330	BIT(29)
+#define RCU_RD_GPHY2_XRX330	BIT(28)
+#define RCU_RD_GPHY3_XRX330	BIT(10)
+
+/* reset cause */
+#define RCU_STAT_SHIFT		26
+/* boot selection */
+#define RCU_BOOT_SEL(x)		((x >> 18) & 0x7)
+#define RCU_BOOT_SEL_XRX200(x)	(((x >> 17) & 0xf) | ((x >> 8) & 0x10))
+
+/* dwc2 USB configuration registers */
+#define RCU_USB1CFG		0x0018
+#define RCU_USB2CFG		0x0034
+
+/* USB DMA endianness bits */
+#define RCU_USBCFG_HDSEL_BIT	BIT(11)
+#define RCU_USBCFG_HOST_END_BIT	BIT(10)
+#define RCU_USBCFG_SLV_END_BIT	BIT(9)
+
+/* USB reset bits */
+#define RCU_USBRESET		0x0010
+
+#define USBRESET_BIT		BIT(4)
+
+#define RCU_USBRESET2		0x0048
+
+#define USB1RESET_BIT		BIT(4)
+#define USB2RESET_BIT		BIT(5)
+
+#define RCU_CFG1A		0x0038
+#define RCU_CFG1B		0x003C
+
+/* USB PMU devices */
+#define PMU_AHBM		BIT(15)
+#define PMU_USB0		BIT(6)
+#define PMU_USB1		BIT(27)
+
+/* USB PHY PMU devices */
+#define PMU_USB0_P		BIT(0)
+#define PMU_USB1_P		BIT(26)
+
+/* remapped base addr of the reset control unit */
+static void __iomem *ltq_rcu_membase;
+static struct device_node *ltq_rcu_np;
+static DEFINE_SPINLOCK(ltq_rcu_lock);
+
+static void ltq_rcu_w32(uint32_t val, uint32_t reg_off)
+{
+	ltq_w32(val, ltq_rcu_membase + reg_off);
+}
+
+static uint32_t ltq_rcu_r32(uint32_t reg_off)
+{
+	return ltq_r32(ltq_rcu_membase + reg_off);
+}
+
+static void ltq_rcu_w32_mask(uint32_t clr, uint32_t set, uint32_t reg_off)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ltq_rcu_lock, flags);
+	ltq_rcu_w32((ltq_rcu_r32(reg_off) & ~(clr)) | (set), reg_off);
+	spin_unlock_irqrestore(&ltq_rcu_lock, flags);
+}
+
+/* This function is used by the watchdog driver */
+int ltq_reset_cause(void)
+{
+	u32 val = ltq_rcu_r32(RCU_RST_STAT);
+	return val >> RCU_STAT_SHIFT;
+}
+EXPORT_SYMBOL_GPL(ltq_reset_cause);
+
+/* allow platform code to find out what source we booted from */
+unsigned char ltq_boot_select(void)
+{
+	u32 val = ltq_rcu_r32(RCU_RST_STAT);
+
+	if (of_device_is_compatible(ltq_rcu_np, "lantiq,rcu-xrx200"))
+		return RCU_BOOT_SEL_XRX200(val);
+
+	return RCU_BOOT_SEL(val);
+}
+
+struct ltq_gphy_reset {
+	u32 rd;
+	u32 addr;
+};
+
+/* reset / boot a gphy */
+static struct ltq_gphy_reset xrx200_gphy[] = {
+	{RCU_RD_GPHY0_XRX200, RCU_GFS_ADD0_XRX200},
+	{RCU_RD_GPHY1_XRX200, RCU_GFS_ADD1_XRX200},
+};
+
+/* reset / boot a gphy */
+static struct ltq_gphy_reset xrx300_gphy[] = {
+	{RCU_RD_GPHY0_XRX300, RCU_GFS_ADD0_XRX300},
+	{RCU_RD_GPHY1_XRX300, RCU_GFS_ADD1_XRX300},
+	{RCU_RD_GPHY2_XRX300, RCU_GFS_ADD2_XRX300},
+};
+
+/* reset / boot a gphy */
+static struct ltq_gphy_reset xrx330_gphy[] = {
+	{RCU_RD_GPHY0_XRX330, RCU_GFS_ADD0_XRX330},
+	{RCU_RD_GPHY1_XRX330, RCU_GFS_ADD1_XRX330},
+	{RCU_RD_GPHY2_XRX330, RCU_GFS_ADD2_XRX330},
+	{RCU_RD_GPHY3_XRX330, RCU_GFS_ADD3_XRX330},
+};
+
+static void xrx200_gphy_boot_addr(struct ltq_gphy_reset *phy_regs,
+				  dma_addr_t dev_addr)
+{
+	ltq_rcu_w32_mask(0, phy_regs->rd, RCU_RST_REQ);
+	ltq_rcu_w32(dev_addr, phy_regs->addr);
+	ltq_rcu_w32_mask(phy_regs->rd, 0,  RCU_RST_REQ);
+}
+
+/* reset and boot a gphy. these phys only exist on xrx200 SoC */
+int xrx200_gphy_boot(struct device *dev, unsigned int id, dma_addr_t dev_addr)
+{
+	struct clk *clk;
+
+	if (!of_device_is_compatible(ltq_rcu_np, "lantiq,rcu-xrx200")) {
+		dev_err(dev, "this SoC has no GPHY\n");
+		return -EINVAL;
+	}
+
+	if (of_machine_is_compatible("lantiq,vr9")) {
+		clk = clk_get_sys("1f203000.rcu", "gphy");
+		if (IS_ERR(clk))
+			return PTR_ERR(clk);
+		clk_enable(clk);
+	}
+
+	dev_info(dev, "booting GPHY%u firmware at %X\n", id, dev_addr);
+
+	if (of_machine_is_compatible("lantiq,vr9")) {
+		if (id >= ARRAY_SIZE(xrx200_gphy)) {
+			dev_err(dev, "%u is an invalid gphy id\n", id);
+			return -EINVAL;
+		}
+		xrx200_gphy_boot_addr(&xrx200_gphy[id], dev_addr);
+	} else if (of_machine_is_compatible("lantiq,ar10")) {
+		if (id >= ARRAY_SIZE(xrx300_gphy)) {
+			dev_err(dev, "%u is an invalid gphy id\n", id);
+			return -EINVAL;
+		}
+		xrx200_gphy_boot_addr(&xrx300_gphy[id], dev_addr);
+	} else if (of_machine_is_compatible("lantiq,grx390")) {
+		if (id >= ARRAY_SIZE(xrx330_gphy)) {
+			dev_err(dev, "%u is an invalid gphy id\n", id);
+			return -EINVAL;
+		}
+		xrx200_gphy_boot_addr(&xrx330_gphy[id], dev_addr);
+	}
+	return 0;
+}
+
+/* reset a io domain for u micro seconds */
+void ltq_reset_once(unsigned int module, ulong u)
+{
+	ltq_rcu_w32(ltq_rcu_r32(RCU_RST_REQ) | module, RCU_RST_REQ);
+	udelay(u);
+	ltq_rcu_w32(ltq_rcu_r32(RCU_RST_REQ) & ~module, RCU_RST_REQ);
+}
+
+static int ltq_assert_device(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	u32 val;
+
+	if (id < 8)
+		return -1;
+
+	val = ltq_rcu_r32(RCU_RST_REQ);
+	val |= BIT(id);
+	ltq_rcu_w32(val, RCU_RST_REQ);
+
+	return 0;
+}
+
+static int ltq_deassert_device(struct reset_controller_dev *rcdev,
+				  unsigned long id)
+{
+	u32 val;
+
+	if (id < 8)
+		return -1;
+
+	val = ltq_rcu_r32(RCU_RST_REQ);
+	val &= ~BIT(id);
+	ltq_rcu_w32(val, RCU_RST_REQ);
+
+	return 0;
+}
+
+static int ltq_reset_device(struct reset_controller_dev *rcdev,
+			       unsigned long id)
+{
+	ltq_assert_device(rcdev, id);
+	return ltq_deassert_device(rcdev, id);
+}
+
+static struct reset_control_ops reset_ops = {
+	.reset = ltq_reset_device,
+	.assert = ltq_assert_device,
+	.deassert = ltq_deassert_device,
+};
+
+static struct reset_controller_dev reset_dev = {
+	.ops			= &reset_ops,
+	.owner			= THIS_MODULE,
+	.nr_resets		= 32,
+	.of_reset_n_cells	= 1,
+};
+
+void ltq_rst_init(void)
+{
+	reset_dev.of_node = of_find_compatible_node(NULL, NULL,
+						"lantiq,xway-reset");
+	if (!reset_dev.of_node)
+		pr_err("Failed to find reset controller node");
+	else
+		reset_controller_register(&reset_dev);
+}
+
+static void ltq_machine_restart(char *command)
+{
+	u32 val = ltq_rcu_r32(RCU_RST_REQ);
+
+	if (of_device_is_compatible(ltq_rcu_np, "lantiq,rcu-xrx200"))
+		val |= RCU_RD_GPHY1_XRX200 | RCU_RD_GPHY0_XRX200;
+
+	val |= RCU_RD_SRST;
+
+	local_irq_disable();
+	ltq_rcu_w32(val, RCU_RST_REQ);
+	unreachable();
+}
+
+static void ltq_machine_halt(void)
+{
+	local_irq_disable();
+	unreachable();
+}
+
+static void ltq_machine_power_off(void)
+{
+	local_irq_disable();
+	unreachable();
+}
+
+static void ltq_usb_init(void)
+{
+	/* Power for USB cores 1 & 2 */
+	ltq_pmu_enable(PMU_AHBM);
+	ltq_pmu_enable(PMU_USB0);
+	ltq_pmu_enable(PMU_USB1);
+
+	ltq_rcu_w32(ltq_rcu_r32(RCU_CFG1A) | BIT(0), RCU_CFG1A);
+	ltq_rcu_w32(ltq_rcu_r32(RCU_CFG1B) | BIT(0), RCU_CFG1B);
+
+	/* Enable USB PHY power for cores 1 & 2 */
+	ltq_pmu_enable(PMU_USB0_P);
+	ltq_pmu_enable(PMU_USB1_P);
+
+	/* Configure cores to host mode */
+	ltq_rcu_w32(ltq_rcu_r32(RCU_USB1CFG) & ~RCU_USBCFG_HDSEL_BIT,
+		RCU_USB1CFG);
+	ltq_rcu_w32(ltq_rcu_r32(RCU_USB2CFG) & ~RCU_USBCFG_HDSEL_BIT,
+		RCU_USB2CFG);
+
+	/* Select DMA endianness (Host-endian: big-endian) */
+	ltq_rcu_w32((ltq_rcu_r32(RCU_USB1CFG) & ~RCU_USBCFG_SLV_END_BIT)
+		| RCU_USBCFG_HOST_END_BIT, RCU_USB1CFG);
+	ltq_rcu_w32(ltq_rcu_r32((RCU_USB2CFG) & ~RCU_USBCFG_SLV_END_BIT)
+		| RCU_USBCFG_HOST_END_BIT, RCU_USB2CFG);
+
+	/* Hard reset USB state machines */
+	ltq_rcu_w32(ltq_rcu_r32(RCU_USBRESET) | USBRESET_BIT, RCU_USBRESET);
+	udelay(50 * 1000);
+	ltq_rcu_w32(ltq_rcu_r32(RCU_USBRESET) & ~USBRESET_BIT, RCU_USBRESET);
+
+	/* Soft reset USB state machines */
+	ltq_rcu_w32(ltq_rcu_r32(RCU_USBRESET2)
+		| USB1RESET_BIT | USB2RESET_BIT, RCU_USBRESET2);
+	udelay(50 * 1000);
+	ltq_rcu_w32(ltq_rcu_r32(RCU_USBRESET2)
+		& ~(USB1RESET_BIT | USB2RESET_BIT), RCU_USBRESET2);
+}
+
+static int __init mips_reboot_setup(void)
+{
+	struct resource res;
+
+	ltq_rcu_np = of_find_compatible_node(NULL, NULL, "lantiq,rcu-xway");
+	if (!ltq_rcu_np)
+		ltq_rcu_np = of_find_compatible_node(NULL, NULL,
+							"lantiq,rcu-xrx200");
+
+	/* check if all the reset register range is available */
+	if (!ltq_rcu_np)
+		panic("Failed to load reset resources from devicetree");
+
+	if (of_address_to_resource(ltq_rcu_np, 0, &res))
+		panic("Failed to get rcu memory range");
+
+	if (!request_mem_region(res.start, resource_size(&res), res.name))
+		pr_err("Failed to request rcu memory");
+
+	ltq_rcu_membase = ioremap_nocache(res.start, resource_size(&res));
+	if (!ltq_rcu_membase)
+		panic("Failed to remap core memory");
+
+	if (of_machine_is_compatible("lantiq,ar9") ||
+	    of_machine_is_compatible("lantiq,vr9"))
+		ltq_usb_init();
+
+	if (of_machine_is_compatible("lantiq,vr9"))
+		ltq_rcu_w32(ltq_rcu_r32(RCU_AHB_ENDIAN) | RCU_VR9_BE_AHB1S,
+			    RCU_AHB_ENDIAN);
+
+	_machine_restart = ltq_machine_restart;
+	_machine_halt = ltq_machine_halt;
+	pm_power_off = ltq_machine_power_off;
+
+	return 0;
+}
+
+arch_initcall(mips_reboot_setup);