Merge tag 'ixp4xx-drivers-arm-soc-v5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-nomadik into arm/drivers

IXP4xx driver updates for modernizing the IXP4xx platforms,
taregeted for v5.15:

- Add DT bindings to the expansion bus and PATA libata driver.

- Add a new expansion bus driver.

- Rewrite the watchdog driver to use the watchdog core and
  spawn from the timer (clocksource) driver.

- Refactor the PATA/libata driver to probe from the device
  tree and use the expansion bus driver to manipulate chip
  select timings directly.

* tag 'ixp4xx-drivers-arm-soc-v5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-nomadik:
  pata: ixp4xx: Rewrite to use device tree
  pata: ixp4xx: Add DT bindings
  pata: ixp4xx: Refer to cmd and ctl rather than csN
  pata: ixp4xx: Use IS_ENABLED() to determine endianness
  pata: ixp4xx: Use local dev variable
  watchdog: ixp4xx: Rewrite driver to use core
  bus: ixp4xx: Add a driver for IXP4xx expansion bus
  bus: ixp4xx: Add DT bindings for the IXP4xx expansion bus

Link: https://lore.kernel.org/r/CACRpkdZaCosXsgp02nuUbd_nEvdxm5-z0+d0oSA97UTWQ0RQQg@mail.gmail.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

7 files changed, 781 insertions, 256 deletions

diff --git a/drivers/ata/pata_ixp4xx_cf.c b/drivers/ata/pata_ixp4xx_cf.c
index 5881d64af943..99c63087c8ae 100644
--- a/drivers/ata/pata_ixp4xx_cf.c
+++ b/drivers/ata/pata_ixp4xx_cf.c
@@ -13,45 +13,134 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/libata.h>
 #include <linux/irq.h>
 #include <linux/platform_device.h>
-#include <linux/platform_data/pata_ixp4xx_cf.h>
+#include <linux/regmap.h>
 #include <scsi/scsi_host.h>
 
 #define DRV_NAME	"pata_ixp4xx_cf"
-#define DRV_VERSION	"0.2"
+#define DRV_VERSION	"1.0"
 
-static int ixp4xx_set_mode(struct ata_link *link, struct ata_device **error)
+struct ixp4xx_pata {
+	struct ata_host *host;
+	struct regmap *rmap;
+	u32 cmd_csreg;
+	void __iomem *cmd;
+	void __iomem *ctl;
+};
+
+#define IXP4XX_EXP_TIMING_STRIDE	0x04
+/* The timings for the chipselect is in bits 29..16 */
+#define IXP4XX_EXP_T1_T5_MASK	GENMASK(29, 16)
+#define IXP4XX_EXP_PIO_0_8	0x0a470000
+#define IXP4XX_EXP_PIO_1_8	0x06430000
+#define IXP4XX_EXP_PIO_2_8	0x02410000
+#define IXP4XX_EXP_PIO_3_8	0x00820000
+#define IXP4XX_EXP_PIO_4_8	0x00400000
+#define IXP4XX_EXP_PIO_0_16	0x29640000
+#define IXP4XX_EXP_PIO_1_16	0x05030000
+#define IXP4XX_EXP_PIO_2_16	0x00b20000
+#define IXP4XX_EXP_PIO_3_16	0x00820000
+#define IXP4XX_EXP_PIO_4_16	0x00400000
+#define IXP4XX_EXP_BW_MASK	(BIT(6)|BIT(0))
+#define IXP4XX_EXP_BYTE_RD16	BIT(6) /* Byte reads on half-word devices */
+#define IXP4XX_EXP_BYTE_EN	BIT(0) /* Use 8bit data bus if set */
+
+static void ixp4xx_set_8bit_timing(struct ixp4xx_pata *ixpp, u8 pio_mode)
+{
+	switch (pio_mode) {
+	case XFER_PIO_0:
+		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
+				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_0_8);
+		break;
+	case XFER_PIO_1:
+		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
+				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_1_8);
+		break;
+	case XFER_PIO_2:
+		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
+				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_2_8);
+		break;
+	case XFER_PIO_3:
+		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
+				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_3_8);
+		break;
+	case XFER_PIO_4:
+		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
+				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_4_8);
+		break;
+	default:
+		break;
+	}
+	regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
+			   IXP4XX_EXP_BW_MASK, IXP4XX_EXP_BYTE_RD16|IXP4XX_EXP_BYTE_EN);
+}
+
+static void ixp4xx_set_16bit_timing(struct ixp4xx_pata *ixpp, u8 pio_mode)
 {
-	struct ata_device *dev;
-
-	ata_for_each_dev(dev, link, ENABLED) {
-		ata_dev_info(dev, "configured for PIO0\n");
-		dev->pio_mode = XFER_PIO_0;
-		dev->xfer_mode = XFER_PIO_0;
-		dev->xfer_shift = ATA_SHIFT_PIO;
-		dev->flags |= ATA_DFLAG_PIO;
+	switch (pio_mode){
+	case XFER_PIO_0:
+		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
+				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_0_16);
+		break;
+	case XFER_PIO_1:
+		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
+				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_1_16);
+		break;
+	case XFER_PIO_2:
+		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
+				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_2_16);
+		break;
+	case XFER_PIO_3:
+		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
+				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_3_16);
+		break;
+	case XFER_PIO_4:
+		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
+				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_4_16);
+		break;
+	default:
+		break;
 	}
-	return 0;
+	regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
+			   IXP4XX_EXP_BW_MASK, IXP4XX_EXP_BYTE_RD16);
+}
+
+/* This sets up the timing on the chipselect CMD accordingly */
+static void ixp4xx_set_piomode(struct ata_port *ap, struct ata_device *adev)
+{
+	struct ixp4xx_pata *ixpp = ap->host->private_data;
+
+	ata_dev_printk(adev, KERN_INFO, "configured for PIO%d 8bit\n",
+		       adev->pio_mode - XFER_PIO_0);
+	ixp4xx_set_8bit_timing(ixpp, adev->pio_mode);
 }
 
+
 static unsigned int ixp4xx_mmio_data_xfer(struct ata_queued_cmd *qc,
-				unsigned char *buf, unsigned int buflen, int rw)
+					  unsigned char *buf, unsigned int buflen, int rw)
 {
 	unsigned int i;
 	unsigned int words = buflen >> 1;
 	u16 *buf16 = (u16 *) buf;
+	struct ata_device *adev = qc->dev;
 	struct ata_port *ap = qc->dev->link->ap;
 	void __iomem *mmio = ap->ioaddr.data_addr;
-	struct ixp4xx_pata_data *data = dev_get_platdata(ap->host->dev);
+	struct ixp4xx_pata *ixpp = ap->host->private_data;
+	unsigned long flags;
+
+	ata_dev_printk(adev, KERN_DEBUG, "%s %d bytes\n", (rw == READ) ? "READ" : "WRITE",
+		       buflen);
+	spin_lock_irqsave(ap->lock, flags);
 
 	/* set the expansion bus in 16bit mode and restore
 	 * 8 bit mode after the transaction.
 	 */
-	*data->cs0_cfg &= ~(0x01);
-	udelay(100);
+	ixp4xx_set_16bit_timing(ixpp, adev->pio_mode);
+	udelay(5);
 
 	/* Transfer multiple of 2 bytes */
 	if (rw == READ)
@@ -76,8 +165,10 @@ static unsigned int ixp4xx_mmio_data_xfer(struct ata_queued_cmd *qc,
 		words++;
 	}
 
-	udelay(100);
-	*data->cs0_cfg |= 0x01;
+	ixp4xx_set_8bit_timing(ixpp, adev->pio_mode);
+	udelay(5);
+
+	spin_unlock_irqrestore(ap->lock, flags);
 
 	return words << 1;
 }
@@ -90,79 +181,98 @@ static struct ata_port_operations ixp4xx_port_ops = {
 	.inherits		= &ata_sff_port_ops,
 	.sff_data_xfer		= ixp4xx_mmio_data_xfer,
 	.cable_detect		= ata_cable_40wire,
-	.set_mode		= ixp4xx_set_mode,
+	.set_piomode		= ixp4xx_set_piomode,
+};
+
+static struct ata_port_info ixp4xx_port_info = {
+	.flags		= ATA_FLAG_NO_ATAPI,
+	.pio_mask	= ATA_PIO4,
+	.port_ops	= &ixp4xx_port_ops,
 };
 
 static void ixp4xx_setup_port(struct ata_port *ap,
-			      struct ixp4xx_pata_data *data,
-			      unsigned long raw_cs0, unsigned long raw_cs1)
+			      struct ixp4xx_pata *ixpp,
+			      unsigned long raw_cmd, unsigned long raw_ctl)
 {
 	struct ata_ioports *ioaddr = &ap->ioaddr;
-	unsigned long raw_cmd = raw_cs0;
-	unsigned long raw_ctl = raw_cs1 + 0x06;
 
-	ioaddr->cmd_addr	= data->cs0;
-	ioaddr->altstatus_addr	= data->cs1 + 0x06;
-	ioaddr->ctl_addr	= data->cs1 + 0x06;
+	raw_ctl += 0x06;
+	ioaddr->cmd_addr	= ixpp->cmd;
+	ioaddr->altstatus_addr	= ixpp->ctl + 0x06;
+	ioaddr->ctl_addr	= ixpp->ctl + 0x06;
 
 	ata_sff_std_ports(ioaddr);
 
-#ifndef __ARMEB__
-
-	/* adjust the addresses to handle the address swizzling of the
-	 * ixp4xx in little endian mode.
-	 */
-
-	*(unsigned long *)&ioaddr->data_addr		^= 0x02;
-	*(unsigned long *)&ioaddr->cmd_addr		^= 0x03;
-	*(unsigned long *)&ioaddr->altstatus_addr	^= 0x03;
-	*(unsigned long *)&ioaddr->ctl_addr		^= 0x03;
-	*(unsigned long *)&ioaddr->error_addr		^= 0x03;
-	*(unsigned long *)&ioaddr->feature_addr		^= 0x03;
-	*(unsigned long *)&ioaddr->nsect_addr		^= 0x03;
-	*(unsigned long *)&ioaddr->lbal_addr		^= 0x03;
-	*(unsigned long *)&ioaddr->lbam_addr		^= 0x03;
-	*(unsigned long *)&ioaddr->lbah_addr		^= 0x03;
-	*(unsigned long *)&ioaddr->device_addr		^= 0x03;
-	*(unsigned long *)&ioaddr->status_addr		^= 0x03;
-	*(unsigned long *)&ioaddr->command_addr		^= 0x03;
-
-	raw_cmd ^= 0x03;
-	raw_ctl ^= 0x03;
-#endif
+	if (!IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) {
+		/* adjust the addresses to handle the address swizzling of the
+		 * ixp4xx in little endian mode.
+		 */
+
+		*(unsigned long *)&ioaddr->data_addr		^= 0x02;
+		*(unsigned long *)&ioaddr->cmd_addr		^= 0x03;
+		*(unsigned long *)&ioaddr->altstatus_addr	^= 0x03;
+		*(unsigned long *)&ioaddr->ctl_addr		^= 0x03;
+		*(unsigned long *)&ioaddr->error_addr		^= 0x03;
+		*(unsigned long *)&ioaddr->feature_addr		^= 0x03;
+		*(unsigned long *)&ioaddr->nsect_addr		^= 0x03;
+		*(unsigned long *)&ioaddr->lbal_addr		^= 0x03;
+		*(unsigned long *)&ioaddr->lbam_addr		^= 0x03;
+		*(unsigned long *)&ioaddr->lbah_addr		^= 0x03;
+		*(unsigned long *)&ioaddr->device_addr		^= 0x03;
+		*(unsigned long *)&ioaddr->status_addr		^= 0x03;
+		*(unsigned long *)&ioaddr->command_addr		^= 0x03;
+
+		raw_cmd ^= 0x03;
+		raw_ctl ^= 0x03;
+	}
 
 	ata_port_desc(ap, "cmd 0x%lx ctl 0x%lx", raw_cmd, raw_ctl);
 }
 
 static int ixp4xx_pata_probe(struct platform_device *pdev)
 {
-	struct resource *cs0, *cs1;
-	struct ata_host *host;
-	struct ata_port *ap;
-	struct ixp4xx_pata_data *data = dev_get_platdata(&pdev->dev);
+	struct resource *cmd, *ctl;
+	struct ata_port_info pi = ixp4xx_port_info;
+	const struct ata_port_info *ppi[] = { &pi, NULL };
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct ixp4xx_pata *ixpp;
+	u32 csindex;
 	int ret;
 	int irq;
 
-	cs0 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	cs1 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	cmd = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ctl = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 
-	if (!cs0 || !cs1)
+	if (!cmd || !ctl)
 		return -EINVAL;
 
-	/* allocate host */
-	host = ata_host_alloc(&pdev->dev, 1);
-	if (!host)
+	ixpp = devm_kzalloc(dev, sizeof(*ixpp), GFP_KERNEL);
+	if (!ixpp)
 		return -ENOMEM;
 
-	/* acquire resources and fill host */
-	ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
+	ixpp->rmap = syscon_node_to_regmap(np->parent);
+	if (IS_ERR(ixpp->rmap))
+		return dev_err_probe(dev, PTR_ERR(ixpp->rmap), "no regmap\n");
+	/* Inspect our address to figure out what chipselect the CMD is on */
+	ret = of_property_read_u32_index(np, "reg", 0, &csindex);
 	if (ret)
-		return ret;
+		return dev_err_probe(dev, ret, "can't inspect CMD address\n");
+	dev_info(dev, "using CS%d for PIO timing configuration\n", csindex);
+	ixpp->cmd_csreg = csindex * IXP4XX_EXP_TIMING_STRIDE;
 
-	data->cs0 = devm_ioremap(&pdev->dev, cs0->start, 0x1000);
-	data->cs1 = devm_ioremap(&pdev->dev, cs1->start, 0x1000);
+	ixpp->host = ata_host_alloc_pinfo(dev, ppi, 1);
+	if (!ixpp->host)
+		return -ENOMEM;
+	ixpp->host->private_data = ixpp;
 
-	if (!data->cs0 || !data->cs1)
+	ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
+	if (ret)
+		return ret;
+
+	ixpp->cmd = devm_ioremap_resource(dev, cmd);
+	ixpp->ctl = devm_ioremap_resource(dev, ctl);
+	if (IS_ERR(ixpp->cmd) || IS_ERR(ixpp->ctl))
 		return -ENOMEM;
 
 	irq = platform_get_irq(pdev, 0);
@@ -173,27 +283,23 @@ static int ixp4xx_pata_probe(struct platform_device *pdev)
 	else
 		return -EINVAL;
 
-	/* Setup expansion bus chip selects */
-	*data->cs0_cfg = data->cs0_bits;
-	*data->cs1_cfg = data->cs1_bits;
-
-	ap = host->ports[0];
-
-	ap->ops	= &ixp4xx_port_ops;
-	ap->pio_mask = ATA_PIO4;
-	ap->flags |= ATA_FLAG_NO_ATAPI;
+	/* Just one port to set up */
+	ixp4xx_setup_port(ixpp->host->ports[0], ixpp, cmd->start, ctl->start);
 
-	ixp4xx_setup_port(ap, data, cs0->start, cs1->start);
+	ata_print_version_once(dev, DRV_VERSION);
 
-	ata_print_version_once(&pdev->dev, DRV_VERSION);
-
-	/* activate host */
-	return ata_host_activate(host, irq, ata_sff_interrupt, 0, &ixp4xx_sht);
+	return ata_host_activate(ixpp->host, irq, ata_sff_interrupt, 0, &ixp4xx_sht);
 }
 
+static const struct of_device_id ixp4xx_pata_of_match[] = {
+	{ .compatible = "intel,ixp4xx-compact-flash", },
+	{ },
+};
+
 static struct platform_driver ixp4xx_pata_platform_driver = {
 	.driver	 = {
 		.name   = DRV_NAME,
+		.of_match_table = ixp4xx_pata_of_match,
 	},
 	.probe		= ixp4xx_pata_probe,
 	.remove		= ata_platform_remove_one,
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index e7f7eee6ee9a..a5b96f3aad67 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -95,6 +95,17 @@ config IMX_WEIM
 	  The WEIM(Wireless External Interface Module) works like a bus.
 	  You can attach many different devices on it, such as NOR, onenand.
 
+config INTEL_IXP4XX_EB
+	bool "Intel IXP4xx expansion bus interface driver"
+	depends on HAS_IOMEM
+	depends on ARCH_IXP4XX || COMPILE_TEST
+	default ARCH_IXP4XX
+	select MFD_SYSCON
+	help
+	  Driver for the Intel IXP4xx expansion bus interface. The driver is
+	  needed to set up various chip select configuration parameters before
+	  devices on the expansion bus can be discovered.
+
 config MIPS_CDMM
 	bool "MIPS Common Device Memory Map (CDMM) Driver"
 	depends on CPU_MIPSR2 || CPU_MIPSR5
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index 397e35392bff..1c29c5e8ffb8 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_FSL_MC_BUS)	+= fsl-mc/
 obj-$(CONFIG_BT1_APB)		+= bt1-apb.o
 obj-$(CONFIG_BT1_AXI)		+= bt1-axi.o
 obj-$(CONFIG_IMX_WEIM)		+= imx-weim.o
+obj-$(CONFIG_INTEL_IXP4XX_EB)	+= intel-ixp4xx-eb.o
 obj-$(CONFIG_MIPS_CDMM)		+= mips_cdmm.o
 obj-$(CONFIG_MVEBU_MBUS) 	+= mvebu-mbus.o
 
diff --git a/drivers/bus/intel-ixp4xx-eb.c b/drivers/bus/intel-ixp4xx-eb.c
new file mode 100644
index 000000000000..9acd00da413c
--- /dev/null
+++ b/drivers/bus/intel-ixp4xx-eb.c
@@ -0,0 +1,429 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel IXP4xx Expansion Bus Controller
+ * Copyright (C) 2021 Linaro Ltd.
+ *
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/log2.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define IXP4XX_EXP_NUM_CS		8
+
+#define IXP4XX_EXP_TIMING_CS0		0x00
+#define IXP4XX_EXP_TIMING_CS1		0x04
+#define IXP4XX_EXP_TIMING_CS2		0x08
+#define IXP4XX_EXP_TIMING_CS3		0x0c
+#define IXP4XX_EXP_TIMING_CS4		0x10
+#define IXP4XX_EXP_TIMING_CS5		0x14
+#define IXP4XX_EXP_TIMING_CS6		0x18
+#define IXP4XX_EXP_TIMING_CS7		0x1c
+
+/* Bits inside each CS timing register */
+#define IXP4XX_EXP_TIMING_STRIDE	0x04
+#define IXP4XX_EXP_CS_EN		BIT(31)
+#define IXP456_EXP_PAR_EN		BIT(30) /* Only on IXP45x and IXP46x */
+#define IXP4XX_EXP_T1_MASK		GENMASK(28, 27)
+#define IXP4XX_EXP_T1_SHIFT		28
+#define IXP4XX_EXP_T2_MASK		GENMASK(27, 26)
+#define IXP4XX_EXP_T2_SHIFT		26
+#define IXP4XX_EXP_T3_MASK		GENMASK(25, 22)
+#define IXP4XX_EXP_T3_SHIFT		22
+#define IXP4XX_EXP_T4_MASK		GENMASK(21, 20)
+#define IXP4XX_EXP_T4_SHIFT		20
+#define IXP4XX_EXP_T5_MASK		GENMASK(19, 16)
+#define IXP4XX_EXP_T5_SHIFT		16
+#define IXP4XX_EXP_CYC_TYPE_MASK	GENMASK(15, 14)
+#define IXP4XX_EXP_CYC_TYPE_SHIFT	14
+#define IXP4XX_EXP_SIZE_MASK		GENMASK(13, 10)
+#define IXP4XX_EXP_SIZE_SHIFT		10
+#define IXP4XX_EXP_CNFG_0		BIT(9) /* Always zero */
+#define IXP43X_EXP_SYNC_INTEL		BIT(8) /* Only on IXP43x */
+#define IXP43X_EXP_EXP_CHIP		BIT(7) /* Only on IXP43x */
+#define IXP4XX_EXP_BYTE_RD16		BIT(6)
+#define IXP4XX_EXP_HRDY_POL		BIT(5) /* Only on IXP42x */
+#define IXP4XX_EXP_MUX_EN		BIT(4)
+#define IXP4XX_EXP_SPLT_EN		BIT(3)
+#define IXP4XX_EXP_WORD			BIT(2) /* Always zero */
+#define IXP4XX_EXP_WR_EN		BIT(1)
+#define IXP4XX_EXP_BYTE_EN		BIT(0)
+#define IXP42X_RESERVED			(BIT(30)|IXP4XX_EXP_CNFG_0|BIT(8)|BIT(7)|IXP4XX_EXP_WORD)
+#define IXP43X_RESERVED			(BIT(30)|IXP4XX_EXP_CNFG_0|BIT(5)|IXP4XX_EXP_WORD)
+
+#define IXP4XX_EXP_CNFG0		0x20
+#define IXP4XX_EXP_CNFG0_MEM_MAP	BIT(31)
+#define IXP4XX_EXP_CNFG1		0x24
+
+#define IXP4XX_EXP_BOOT_BASE		0x00000000
+#define IXP4XX_EXP_NORMAL_BASE		0x50000000
+#define IXP4XX_EXP_STRIDE		0x01000000
+
+/* Fuses on the IXP43x */
+#define IXP43X_EXP_UNIT_FUSE_RESET	0x28
+#define IXP43x_EXP_FUSE_SPEED_MASK	GENMASK(23, 22)
+
+/* Number of device tree values in "reg" */
+#define IXP4XX_OF_REG_SIZE		3
+
+struct ixp4xx_eb {
+	struct device *dev;
+	struct regmap *rmap;
+	u32 bus_base;
+	bool is_42x;
+	bool is_43x;
+};
+
+struct ixp4xx_exp_tim_prop {
+	const char *prop;
+	u32 max;
+	u32 mask;
+	u16 shift;
+};
+
+static const struct ixp4xx_exp_tim_prop ixp4xx_exp_tim_props[] = {
+	{
+		.prop = "intel,ixp4xx-eb-t1",
+		.max = 3,
+		.mask = IXP4XX_EXP_T1_MASK,
+		.shift = IXP4XX_EXP_T1_SHIFT,
+	},
+	{
+		.prop = "intel,ixp4xx-eb-t2",
+		.max = 3,
+		.mask = IXP4XX_EXP_T2_MASK,
+		.shift = IXP4XX_EXP_T2_SHIFT,
+	},
+	{
+		.prop = "intel,ixp4xx-eb-t3",
+		.max = 15,
+		.mask = IXP4XX_EXP_T3_MASK,
+		.shift = IXP4XX_EXP_T3_SHIFT,
+	},
+	{
+		.prop = "intel,ixp4xx-eb-t4",
+		.max = 3,
+		.mask = IXP4XX_EXP_T4_MASK,
+		.shift = IXP4XX_EXP_T4_SHIFT,
+	},
+	{
+		.prop = "intel,ixp4xx-eb-t5",
+		.max = 15,
+		.mask = IXP4XX_EXP_T5_MASK,
+		.shift = IXP4XX_EXP_T5_SHIFT,
+	},
+	{
+		.prop = "intel,ixp4xx-eb-byte-access-on-halfword",
+		.max = 1,
+		.mask = IXP4XX_EXP_BYTE_RD16,
+	},
+	{
+		.prop = "intel,ixp4xx-eb-hpi-hrdy-pol-high",
+		.max = 1,
+		.mask = IXP4XX_EXP_HRDY_POL,
+	},
+	{
+		.prop = "intel,ixp4xx-eb-mux-address-and-data",
+		.max = 1,
+		.mask = IXP4XX_EXP_MUX_EN,
+	},
+	{
+		.prop = "intel,ixp4xx-eb-ahb-split-transfers",
+		.max = 1,
+		.mask = IXP4XX_EXP_SPLT_EN,
+	},
+	{
+		.prop = "intel,ixp4xx-eb-write-enable",
+		.max = 1,
+		.mask = IXP4XX_EXP_WR_EN,
+	},
+	{
+		.prop = "intel,ixp4xx-eb-byte-access",
+		.max = 1,
+		.mask = IXP4XX_EXP_BYTE_EN,
+	},
+};
+
+static void ixp4xx_exp_setup_chipselect(struct ixp4xx_eb *eb,
+					struct device_node *np,
+					u32 cs_index,
+					u32 cs_size)
+{
+	u32 cs_cfg;
+	u32 val;
+	u32 cur_cssize;
+	u32 cs_order;
+	int ret;
+	int i;
+
+	if (eb->is_42x && (cs_index > 7)) {
+		dev_err(eb->dev,
+			"invalid chipselect %u, we only support 0-7\n",
+			cs_index);
+		return;
+	}
+	if (eb->is_43x && (cs_index > 3)) {
+		dev_err(eb->dev,
+			"invalid chipselect %u, we only support 0-3\n",
+			cs_index);
+		return;
+	}
+
+	/* Several chip selects can be joined into one device */
+	if (cs_size > IXP4XX_EXP_STRIDE)
+		cur_cssize = IXP4XX_EXP_STRIDE;
+	else
+		cur_cssize = cs_size;
+
+
+	/*
+	 * The following will read/modify/write the configuration for one
+	 * chipselect, attempting to leave the boot defaults in place unless
+	 * something is explicitly defined.
+	 */
+	regmap_read(eb->rmap, IXP4XX_EXP_TIMING_CS0 +
+		    IXP4XX_EXP_TIMING_STRIDE * cs_index, &cs_cfg);
+	dev_info(eb->dev, "CS%d at %#08x, size %#08x, config before: %#08x\n",
+		 cs_index, eb->bus_base + IXP4XX_EXP_STRIDE * cs_index,
+		 cur_cssize, cs_cfg);
+
+	/* Size set-up first align to 2^9 .. 2^24 */
+	cur_cssize = roundup_pow_of_two(cur_cssize);
+	if (cur_cssize < 512)
+		cur_cssize = 512;
+	cs_order = ilog2(cur_cssize);
+	if (cs_order < 9 || cs_order > 24) {
+		dev_err(eb->dev, "illegal size order %d\n", cs_order);
+		return;
+	}
+	dev_dbg(eb->dev, "CS%d size order: %d\n", cs_index, cs_order);
+	cs_cfg &= ~(IXP4XX_EXP_SIZE_MASK);
+	cs_cfg |= ((cs_order - 9) << IXP4XX_EXP_SIZE_SHIFT);
+
+	for (i = 0; i < ARRAY_SIZE(ixp4xx_exp_tim_props); i++) {
+		const struct ixp4xx_exp_tim_prop *ip = &ixp4xx_exp_tim_props[i];
+
+		/* All are regular u32 values */
+		ret = of_property_read_u32(np, ip->prop, &val);
+		if (ret)
+			continue;
+
+		/* Handle bools (single bits) first */
+		if (ip->max == 1) {
+			if (val)
+				cs_cfg |= ip->mask;
+			else
+				cs_cfg &= ~ip->mask;
+			dev_info(eb->dev, "CS%d %s %s\n", cs_index,
+				 val ? "enabled" : "disabled",
+				 ip->prop);
+			continue;
+		}
+
+		if (val > ip->max) {
+			dev_err(eb->dev,
+				"CS%d too high value for %s: %u, capped at %u\n",
+				cs_index, ip->prop, val, ip->max);
+			val = ip->max;
+		}
+		/* This assumes max value fills all the assigned bits (and it does) */
+		cs_cfg &= ~ip->mask;
+		cs_cfg |= (val << ip->shift);
+		dev_info(eb->dev, "CS%d set %s to %u\n", cs_index, ip->prop, val);
+	}
+
+	ret = of_property_read_u32(np, "intel,ixp4xx-eb-cycle-type", &val);
+	if (!ret) {
+		if (val > 3) {
+			dev_err(eb->dev, "illegal cycle type %d\n", val);
+			return;
+		}
+		dev_info(eb->dev, "CS%d set cycle type %d\n", cs_index, val);
+		cs_cfg &= ~IXP4XX_EXP_CYC_TYPE_MASK;
+		cs_cfg |= val << IXP4XX_EXP_CYC_TYPE_SHIFT;
+	}
+
+	if (eb->is_42x)
+		cs_cfg &= ~IXP42X_RESERVED;
+	if (eb->is_43x) {
+		cs_cfg &= ~IXP43X_RESERVED;
+		/*
+		 * This bit for Intel strata flash is currently unused, but let's
+		 * report it if we find one.
+		 */
+		if (cs_cfg & IXP43X_EXP_SYNC_INTEL)
+			dev_info(eb->dev, "claims to be Intel strata flash\n");
+	}
+	cs_cfg |= IXP4XX_EXP_CS_EN;
+
+	regmap_write(eb->rmap,
+		     IXP4XX_EXP_TIMING_CS0 + IXP4XX_EXP_TIMING_STRIDE * cs_index,
+		     cs_cfg);
+	dev_info(eb->dev, "CS%d wrote %#08x into CS config\n", cs_index, cs_cfg);
+
+	/*
+	 * If several chip selects are joined together into one big
+	 * device area, we call ourselves recursively for each successive
+	 * chip select. For a 32MB flash chip this results in two calls
+	 * for example.
+	 */
+	if (cs_size > IXP4XX_EXP_STRIDE)
+		ixp4xx_exp_setup_chipselect(eb, np,
+					    cs_index + 1,
+					    cs_size - IXP4XX_EXP_STRIDE);
+}
+
+static void ixp4xx_exp_setup_child(struct ixp4xx_eb *eb,
+				   struct device_node *np)
+{
+	u32 cs_sizes[IXP4XX_EXP_NUM_CS];
+	int num_regs;
+	u32 csindex;
+	u32 cssize;
+	int ret;
+	int i;
+
+	num_regs = of_property_count_elems_of_size(np, "reg", IXP4XX_OF_REG_SIZE);
+	if (num_regs <= 0)
+		return;
+	dev_dbg(eb->dev, "child %s has %d register sets\n",
+		of_node_full_name(np), num_regs);
+
+	for (csindex = 0; csindex < IXP4XX_EXP_NUM_CS; csindex++)
+		cs_sizes[csindex] = 0;
+
+	for (i = 0; i < num_regs; i++) {
+		u32 rbase, rsize;
+
+		ret = of_property_read_u32_index(np, "reg",
+						 i * IXP4XX_OF_REG_SIZE, &csindex);
+		if (ret)
+			break;
+		ret = of_property_read_u32_index(np, "reg",
+						 i * IXP4XX_OF_REG_SIZE + 1, &rbase);
+		if (ret)
+			break;
+		ret = of_property_read_u32_index(np, "reg",
+						 i * IXP4XX_OF_REG_SIZE + 2, &rsize);
+		if (ret)
+			break;
+
+		if (csindex >= IXP4XX_EXP_NUM_CS) {
+			dev_err(eb->dev, "illegal CS %d\n", csindex);
+			continue;
+		}
+		/*
+		 * The memory window always starts from CS base so we need to add
+		 * the start and size to get to the size from the start of the CS
+		 * base. For example if CS0 is at 0x50000000 and the reg is
+		 * <0 0xe40000 0x40000> the size is e80000.
+		 *
+		 * Roof this if we have several regs setting the same CS.
+		 */
+		cssize = rbase + rsize;
+		dev_dbg(eb->dev, "CS%d size %#08x\n", csindex, cssize);
+		if (cs_sizes[csindex] < cssize)
+			cs_sizes[csindex] = cssize;
+	}
+
+	for (csindex = 0; csindex < IXP4XX_EXP_NUM_CS; csindex++) {
+		cssize = cs_sizes[csindex];
+		if (!cssize)
+			continue;
+		/* Just this one, so set it up and return */
+		ixp4xx_exp_setup_chipselect(eb, np, csindex, cssize);
+	}
+}
+
+static int ixp4xx_exp_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct ixp4xx_eb *eb;
+	struct device_node *child;
+	bool have_children = false;
+	u32 val;
+	int ret;
+
+	eb = devm_kzalloc(dev, sizeof(*eb), GFP_KERNEL);
+	if (!eb)
+		return -ENOMEM;
+
+	eb->dev = dev;
+	eb->is_42x = of_device_is_compatible(np, "intel,ixp42x-expansion-bus-controller");
+	eb->is_43x = of_device_is_compatible(np, "intel,ixp43x-expansion-bus-controller");
+
+	eb->rmap = syscon_node_to_regmap(np);
+	if (IS_ERR(eb->rmap))
+		return dev_err_probe(dev, PTR_ERR(eb->rmap), "no regmap\n");
+
+	/* We check that the regmap work only on first read */
+	ret = regmap_read(eb->rmap, IXP4XX_EXP_CNFG0, &val);
+	if (ret)
+		dev_err_probe(dev, ret, "cannot read regmap\n");
+	if (val & IXP4XX_EXP_CNFG0_MEM_MAP)
+		eb->bus_base = IXP4XX_EXP_BOOT_BASE;
+	else
+		eb->bus_base = IXP4XX_EXP_NORMAL_BASE;
+	dev_info(dev, "expansion bus at %08x\n", eb->bus_base);
+
+	if (eb->is_43x) {
+		/* Check some fuses */
+		regmap_read(eb->rmap, IXP43X_EXP_UNIT_FUSE_RESET, &val);
+		switch (FIELD_GET(IXP43x_EXP_FUSE_SPEED_MASK, val)) {
+		case 0:
+			dev_info(dev, "IXP43x at 533 MHz\n");
+			break;
+		case 1:
+			dev_info(dev, "IXP43x at 400 MHz\n");
+			break;
+		case 2:
+			dev_info(dev, "IXP43x at 667 MHz\n");
+			break;
+		default:
+			dev_info(dev, "IXP43x unknown speed\n");
+			break;
+		}
+	}
+
+	/* Walk over the child nodes and see what chipselects we use */
+	for_each_available_child_of_node(np, child) {
+		ixp4xx_exp_setup_child(eb, child);
+		/* We have at least one child */
+		have_children = true;
+	}
+
+	if (have_children)
+		return of_platform_default_populate(np, NULL, dev);
+
+	return 0;
+}
+
+static const struct of_device_id ixp4xx_exp_of_match[] = {
+	{ .compatible = "intel,ixp42x-expansion-bus-controller", },
+	{ .compatible = "intel,ixp43x-expansion-bus-controller", },
+	{ .compatible = "intel,ixp45x-expansion-bus-controller", },
+	{ .compatible = "intel,ixp46x-expansion-bus-controller", },
+	{ }
+};
+
+static struct platform_driver ixp4xx_exp_driver = {
+	.probe = ixp4xx_exp_probe,
+	.driver = {
+		.name = "intel-extbus",
+		.of_match_table = ixp4xx_exp_of_match,
+	},
+};
+module_platform_driver(ixp4xx_exp_driver);
+MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
+MODULE_DESCRIPTION("Intel IXP4xx external bus driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/clocksource/timer-ixp4xx.c b/drivers/clocksource/timer-ixp4xx.c
index 9396745e1c17..cbb184953510 100644
--- a/drivers/clocksource/timer-ixp4xx.c
+++ b/drivers/clocksource/timer-ixp4xx.c
@@ -18,6 +18,7 @@
 #include <linux/delay.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
+#include <linux/platform_device.h>
 /* Goes away with OF conversion */
 #include <linux/platform_data/timer-ixp4xx.h>
 
@@ -29,9 +30,6 @@
 #define IXP4XX_OSRT1_OFFSET	0x08  /* Timer 1 Reload */
 #define IXP4XX_OST2_OFFSET	0x0C  /* Timer 2 Timestamp */
 #define IXP4XX_OSRT2_OFFSET	0x10  /* Timer 2 Reload */
-#define IXP4XX_OSWT_OFFSET	0x14  /* Watchdog Timer */
-#define IXP4XX_OSWE_OFFSET	0x18  /* Watchdog Enable */
-#define IXP4XX_OSWK_OFFSET	0x1C  /* Watchdog Key */
 #define IXP4XX_OSST_OFFSET	0x20  /* Timer Status */
 
 /*
@@ -45,17 +43,10 @@
 #define IXP4XX_OSST_TIMER_1_PEND	0x00000001
 #define IXP4XX_OSST_TIMER_2_PEND	0x00000002
 #define IXP4XX_OSST_TIMER_TS_PEND	0x00000004
-#define IXP4XX_OSST_TIMER_WDOG_PEND	0x00000008
-#define IXP4XX_OSST_TIMER_WARM_RESET	0x00000010
-
-#define	IXP4XX_WDT_KEY			0x0000482E
-#define	IXP4XX_WDT_RESET_ENABLE		0x00000001
-#define	IXP4XX_WDT_IRQ_ENABLE		0x00000002
-#define	IXP4XX_WDT_COUNT_ENABLE		0x00000004
+/* Remaining registers are for the watchdog and defined in the watchdog driver */
 
 struct ixp4xx_timer {
 	void __iomem *base;
-	unsigned int tick_rate;
 	u32 latch;
 	struct clock_event_device clkevt;
 #ifdef CONFIG_ARM
@@ -181,7 +172,6 @@ static __init int ixp4xx_timer_register(void __iomem *base,
 	if (!tmr)
 		return -ENOMEM;
 	tmr->base = base;
-	tmr->tick_rate = timer_freq;
 
 	/*
 	 * The timer register doesn't allow to specify the two least
@@ -239,6 +229,40 @@ static __init int ixp4xx_timer_register(void __iomem *base,
 	return 0;
 }
 
+static struct platform_device ixp4xx_watchdog_device = {
+	.name = "ixp4xx-watchdog",
+	.id = -1,
+};
+
+/*
+ * This probe gets called after the timer is already up and running. The main
+ * function on this platform is to spawn the watchdog device as a child.
+ */
+static int ixp4xx_timer_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+
+	/* Pass the base address as platform data and nothing else */
+	ixp4xx_watchdog_device.dev.platform_data = local_ixp4xx_timer->base;
+	ixp4xx_watchdog_device.dev.parent = dev;
+	return platform_device_register(&ixp4xx_watchdog_device);
+}
+
+static const struct of_device_id ixp4xx_timer_dt_id[] = {
+	{ .compatible = "intel,ixp4xx-timer", },
+	{ /* sentinel */ },
+};
+
+static struct platform_driver ixp4xx_timer_driver = {
+	.probe  = ixp4xx_timer_probe,
+	.driver = {
+		.name = "ixp4xx-timer",
+		.of_match_table = ixp4xx_timer_dt_id,
+		.suppress_bind_attrs = true,
+	},
+};
+builtin_platform_driver(ixp4xx_timer_driver);
+
 /**
  * ixp4xx_timer_setup() - Timer setup function to be called from boardfiles
  * @timerbase: physical base of timer block
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 546dfc1e2349..0bc7046ab942 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -487,6 +487,7 @@ config FTWDT010_WATCHDOG
 config IXP4XX_WATCHDOG
 	tristate "IXP4xx Watchdog"
 	depends on ARCH_IXP4XX
+	select WATCHDOG_CORE
 	help
 	  Say Y here if to include support for the watchdog timer
 	  in the Intel IXP4xx network processors. This driver can
diff --git a/drivers/watchdog/ixp4xx_wdt.c b/drivers/watchdog/ixp4xx_wdt.c
index aae29dcfaf11..2693ffb24ac7 100644
--- a/drivers/watchdog/ixp4xx_wdt.c
+++ b/drivers/watchdog/ixp4xx_wdt.c
@@ -1,220 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * drivers/char/watchdog/ixp4xx_wdt.c
  *
  * Watchdog driver for Intel IXP4xx network processors
  *
  * Author: Deepak Saxena <dsaxena@plexity.net>
+ * Author: Linus Walleij <linus.walleij@linaro.org>
  *
  * Copyright 2004 (c) MontaVista, Software, Inc.
  * Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
- *
- * 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.
  */
 
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
 #include <linux/module.h>
-#include <linux/moduleparam.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
-#include <linux/fs.h>
-#include <linux/miscdevice.h>
-#include <linux/of.h>
 #include <linux/watchdog.h>
-#include <linux/init.h>
-#include <linux/bitops.h>
-#include <linux/uaccess.h>
-#include <mach/hardware.h>
+#include <linux/bits.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/soc/ixp4xx/cpu.h>
+
+struct ixp4xx_wdt {
+	struct watchdog_device wdd;
+	void __iomem *base;
+	unsigned long rate;
+};
 
-static bool nowayout = WATCHDOG_NOWAYOUT;
-static int heartbeat = 60;	/* (secs) Default is 1 minute */
-static unsigned long wdt_status;
-static unsigned long boot_status;
-static DEFINE_SPINLOCK(wdt_lock);
+/* Fallback if we do not have a clock for this */
+#define IXP4XX_TIMER_FREQ	66666000
 
-#define WDT_TICK_RATE (IXP4XX_PERIPHERAL_BUS_CLOCK * 1000000UL)
+/* Registers after the timer registers */
+#define IXP4XX_OSWT_OFFSET	0x14  /* Watchdog Timer */
+#define IXP4XX_OSWE_OFFSET	0x18  /* Watchdog Enable */
+#define IXP4XX_OSWK_OFFSET	0x1C  /* Watchdog Key */
+#define IXP4XX_OSST_OFFSET	0x20  /* Timer Status */
 
-#define	WDT_IN_USE		0
-#define	WDT_OK_TO_CLOSE		1
+#define IXP4XX_OSST_TIMER_WDOG_PEND	0x00000008
+#define IXP4XX_OSST_TIMER_WARM_RESET	0x00000010
+#define IXP4XX_WDT_KEY			0x0000482E
+#define IXP4XX_WDT_RESET_ENABLE		0x00000001
+#define IXP4XX_WDT_IRQ_ENABLE		0x00000002
+#define IXP4XX_WDT_COUNT_ENABLE		0x00000004
 
-static void wdt_enable(void)
+static inline
+struct ixp4xx_wdt *to_ixp4xx_wdt(struct watchdog_device *wdd)
 {
-	spin_lock(&wdt_lock);
-	*IXP4XX_OSWK = IXP4XX_WDT_KEY;
-	*IXP4XX_OSWE = 0;
-	*IXP4XX_OSWT = WDT_TICK_RATE * heartbeat;
-	*IXP4XX_OSWE = IXP4XX_WDT_COUNT_ENABLE | IXP4XX_WDT_RESET_ENABLE;
-	*IXP4XX_OSWK = 0;
-	spin_unlock(&wdt_lock);
+	return container_of(wdd, struct ixp4xx_wdt, wdd);
 }
 
-static void wdt_disable(void)
+static int ixp4xx_wdt_start(struct watchdog_device *wdd)
 {
-	spin_lock(&wdt_lock);
-	*IXP4XX_OSWK = IXP4XX_WDT_KEY;
-	*IXP4XX_OSWE = 0;
-	*IXP4XX_OSWK = 0;
-	spin_unlock(&wdt_lock);
-}
+	struct ixp4xx_wdt *iwdt = to_ixp4xx_wdt(wdd);
 
-static int ixp4xx_wdt_open(struct inode *inode, struct file *file)
-{
-	if (test_and_set_bit(WDT_IN_USE, &wdt_status))
-		return -EBUSY;
+	__raw_writel(IXP4XX_WDT_KEY, iwdt->base + IXP4XX_OSWK_OFFSET);
+	__raw_writel(0, iwdt->base + IXP4XX_OSWE_OFFSET);
+	__raw_writel(wdd->timeout * iwdt->rate,
+		     iwdt->base + IXP4XX_OSWT_OFFSET);
+	__raw_writel(IXP4XX_WDT_COUNT_ENABLE | IXP4XX_WDT_RESET_ENABLE,
+		     iwdt->base + IXP4XX_OSWE_OFFSET);
+	__raw_writel(0, iwdt->base + IXP4XX_OSWK_OFFSET);
 
-	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
-	wdt_enable();
-	return stream_open(inode, file);
+	return 0;
 }
 
-static ssize_t
-ixp4xx_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
+static int ixp4xx_wdt_stop(struct watchdog_device *wdd)
 {
-	if (len) {
-		if (!nowayout) {
-			size_t i;
-
-			clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
-
-			for (i = 0; i != len; i++) {
-				char c;
-
-				if (get_user(c, data + i))
-					return -EFAULT;
-				if (c == 'V')
-					set_bit(WDT_OK_TO_CLOSE, &wdt_status);
-			}
-		}
-		wdt_enable();
-	}
-	return len;
-}
+	struct ixp4xx_wdt *iwdt = to_ixp4xx_wdt(wdd);
 
-static const struct watchdog_info ident = {
-	.options	= WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
-			  WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
-	.identity	= "IXP4xx Watchdog",
-};
+	__raw_writel(IXP4XX_WDT_KEY, iwdt->base + IXP4XX_OSWK_OFFSET);
+	__raw_writel(0, iwdt->base + IXP4XX_OSWE_OFFSET);
+	__raw_writel(0, iwdt->base + IXP4XX_OSWK_OFFSET);
 
-
-static long ixp4xx_wdt_ioctl(struct file *file, unsigned int cmd,
-							unsigned long arg)
-{
-	int ret = -ENOTTY;
-	int time;
-
-	switch (cmd) {
-	case WDIOC_GETSUPPORT:
-		ret = copy_to_user((struct watchdog_info *)arg, &ident,
-				   sizeof(ident)) ? -EFAULT : 0;
-		break;
-
-	case WDIOC_GETSTATUS:
-		ret = put_user(0, (int *)arg);
-		break;
-
-	case WDIOC_GETBOOTSTATUS:
-		ret = put_user(boot_status, (int *)arg);
-		break;
-
-	case WDIOC_KEEPALIVE:
-		wdt_enable();
-		ret = 0;
-		break;
-
-	case WDIOC_SETTIMEOUT:
-		ret = get_user(time, (int *)arg);
-		if (ret)
-			break;
-
-		if (time <= 0 || time > 60) {
-			ret = -EINVAL;
-			break;
-		}
-
-		heartbeat = time;
-		wdt_enable();
-		fallthrough;
-
-	case WDIOC_GETTIMEOUT:
-		ret = put_user(heartbeat, (int *)arg);
-		break;
-	}
-	return ret;
+	return 0;
 }
 
-static int ixp4xx_wdt_release(struct inode *inode, struct file *file)
+static int ixp4xx_wdt_set_timeout(struct watchdog_device *wdd,
+				  unsigned int timeout)
 {
-	if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
-		wdt_disable();
-	else
-		pr_crit("Device closed unexpectedly - timer will not stop\n");
-	clear_bit(WDT_IN_USE, &wdt_status);
-	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+	wdd->timeout = timeout;
+	if (watchdog_active(wdd))
+		ixp4xx_wdt_start(wdd);
 
 	return 0;
 }
 
-
-static const struct file_operations ixp4xx_wdt_fops = {
-	.owner		= THIS_MODULE,
-	.llseek		= no_llseek,
-	.write		= ixp4xx_wdt_write,
-	.unlocked_ioctl	= ixp4xx_wdt_ioctl,
-	.compat_ioctl	= compat_ptr_ioctl,
-	.open		= ixp4xx_wdt_open,
-	.release	= ixp4xx_wdt_release,
+static const struct watchdog_ops ixp4xx_wdt_ops = {
+	.start = ixp4xx_wdt_start,
+	.stop = ixp4xx_wdt_stop,
+	.set_timeout = ixp4xx_wdt_set_timeout,
+	.owner = THIS_MODULE,
 };
 
-static struct miscdevice ixp4xx_wdt_miscdev = {
-	.minor		= WATCHDOG_MINOR,
-	.name		= "watchdog",
-	.fops		= &ixp4xx_wdt_fops,
+static const struct watchdog_info ixp4xx_wdt_info = {
+	.options = WDIOF_KEEPALIVEPING
+		| WDIOF_MAGICCLOSE
+		| WDIOF_SETTIMEOUT,
+	.identity = KBUILD_MODNAME,
 };
 
-static int __init ixp4xx_wdt_init(void)
+/* Devres-handled clock disablement */
+static void ixp4xx_clock_action(void *d)
+{
+	clk_disable_unprepare(d);
+}
+
+static int ixp4xx_wdt_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
+	struct ixp4xx_wdt *iwdt;
+	struct clk *clk;
 	int ret;
 
-	/*
-	 * FIXME: we bail out on device tree boot but this really needs
-	 * to be fixed in a nicer way: this registers the MDIO bus before
-	 * even matching the driver infrastructure, we should only probe
-	 * detected hardware.
-	 */
-	if (of_have_populated_dt())
-		return -ENODEV;
 	if (!(read_cpuid_id() & 0xf) && !cpu_is_ixp46x()) {
-		pr_err("Rev. A0 IXP42x CPU detected - watchdog disabled\n");
-
+		dev_err(dev, "Rev. A0 IXP42x CPU detected - watchdog disabled\n");
 		return -ENODEV;
 	}
-	boot_status = (*IXP4XX_OSST & IXP4XX_OSST_TIMER_WARM_RESET) ?
-			WDIOF_CARDRESET : 0;
-	ret = misc_register(&ixp4xx_wdt_miscdev);
-	if (ret == 0)
-		pr_info("timer heartbeat %d sec\n", heartbeat);
-	return ret;
-}
 
-static void __exit ixp4xx_wdt_exit(void)
-{
-	misc_deregister(&ixp4xx_wdt_miscdev);
-}
+	iwdt = devm_kzalloc(dev, sizeof(*iwdt), GFP_KERNEL);
+	if (!iwdt)
+		return -ENOMEM;
+	iwdt->base = dev->platform_data;
 
+	/*
+	 * Retrieve rate from a fixed clock from the device tree if
+	 * the parent has that, else use the default clock rate.
+	 */
+	clk = devm_clk_get(dev->parent, NULL);
+	if (!IS_ERR(clk)) {
+		ret = clk_prepare_enable(clk);
+		if (ret)
+			return ret;
+		ret = devm_add_action_or_reset(dev, ixp4xx_clock_action, clk);
+		if (ret)
+			return ret;
+		iwdt->rate = clk_get_rate(clk);
+	}
+	if (!iwdt->rate)
+		iwdt->rate = IXP4XX_TIMER_FREQ;
 
-module_init(ixp4xx_wdt_init);
-module_exit(ixp4xx_wdt_exit);
+	iwdt->wdd.info = &ixp4xx_wdt_info;
+	iwdt->wdd.ops = &ixp4xx_wdt_ops;
+	iwdt->wdd.min_timeout = 1;
+	iwdt->wdd.max_timeout = U32_MAX / iwdt->rate;
+	iwdt->wdd.parent = dev;
+	/* Default to 60 seconds */
+	iwdt->wdd.timeout = 60U;
+	watchdog_init_timeout(&iwdt->wdd, 0, dev);
 
-MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
-MODULE_DESCRIPTION("IXP4xx Network Processor Watchdog");
+	if (__raw_readl(iwdt->base + IXP4XX_OSST_OFFSET) &
+	    IXP4XX_OSST_TIMER_WARM_RESET)
+		iwdt->wdd.bootstatus = WDIOF_CARDRESET;
+
+	ret = devm_watchdog_register_device(dev, &iwdt->wdd);
+	if (ret)
+		return ret;
+
+	dev_info(dev, "IXP4xx watchdog available\n");
 
-module_param(heartbeat, int, 0);
-MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)");
+	return 0;
+}
 
-module_param(nowayout, bool, 0);
-MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
+static struct platform_driver ixp4xx_wdt_driver = {
+	.probe = ixp4xx_wdt_probe,
+	.driver = {
+		.name   = "ixp4xx-watchdog",
+	},
+};
+module_platform_driver(ixp4xx_wdt_driver);
 
+MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
+MODULE_DESCRIPTION("IXP4xx Network Processor Watchdog");
 MODULE_LICENSE("GPL");