drivers/net/dsa/b53/b53_srab.c - linux - Git at Google

 /*
  * B53 register access through Switch Register Access Bridge Registers
  *
  * Copyright (C) 2013 Hauke Mehrtens <hauke@hauke-m.de>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/platform_device.h>
 #include <linux/platform_data/b53.h>
 #include <linux/of.h>

 #include "b53_priv.h"

 /* command and status register of the SRAB */
 #define B53_SRAB_CMDSTAT		0x2c
 #define  B53_SRAB_CMDSTAT_RST		BIT(2)
 #define  B53_SRAB_CMDSTAT_WRITE		BIT(1)
 #define  B53_SRAB_CMDSTAT_GORDYN	BIT(0)
 #define  B53_SRAB_CMDSTAT_PAGE		24
 #define  B53_SRAB_CMDSTAT_REG		16

 /* high order word of write data to switch registe */
 #define B53_SRAB_WD_H			0x30

 /* low order word of write data to switch registe */
 #define B53_SRAB_WD_L			0x34

 /* high order word of read data from switch register */
 #define B53_SRAB_RD_H			0x38

 /* low order word of read data from switch register */
 #define B53_SRAB_RD_L			0x3c

 /* command and status register of the SRAB */
 #define B53_SRAB_CTRLS			0x40
 #define  B53_SRAB_CTRLS_RCAREQ		BIT(3)
 #define  B53_SRAB_CTRLS_RCAGNT		BIT(4)
 #define  B53_SRAB_CTRLS_SW_INIT_DONE	BIT(6)

 /* the register captures interrupt pulses from the switch */
 #define B53_SRAB_INTR			0x44
 #define  B53_SRAB_INTR_P(x)		BIT(x)
 #define  B53_SRAB_SWITCH_PHY		BIT(8)
 #define  B53_SRAB_1588_SYNC		BIT(9)
 #define  B53_SRAB_IMP1_SLEEP_TIMER	BIT(10)
 #define  B53_SRAB_P7_SLEEP_TIMER	BIT(11)
 #define  B53_SRAB_IMP0_SLEEP_TIMER	BIT(12)

 struct b53_srab_priv {
 	void __iomem *regs;
 };

 static int b53_srab_request_grant(struct b53_device *dev)
 {
 	struct b53_srab_priv *priv = dev->priv;
 	u8 __iomem *regs = priv->regs;
 	u32 ctrls;
 	int i;

 	ctrls = readl(regs + B53_SRAB_CTRLS);
 	ctrls |= B53_SRAB_CTRLS_RCAREQ;
 	writel(ctrls, regs + B53_SRAB_CTRLS);

 	for (i = 0; i < 20; i++) {
 		ctrls = readl(regs + B53_SRAB_CTRLS);
 		if (ctrls & B53_SRAB_CTRLS_RCAGNT)
 			break;
 		usleep_range(10, 100);
 	}
 	if (WARN_ON(i == 5))
 		return -EIO;

 	return 0;
 }

 static void b53_srab_release_grant(struct b53_device *dev)
 {
 	struct b53_srab_priv *priv = dev->priv;
 	u8 __iomem *regs = priv->regs;
 	u32 ctrls;

 	ctrls = readl(regs + B53_SRAB_CTRLS);
 	ctrls &= ~B53_SRAB_CTRLS_RCAREQ;
 	writel(ctrls, regs + B53_SRAB_CTRLS);
 }

 static int b53_srab_op(struct b53_device *dev, u8 page, u8 reg, u32 op)
 {
 	struct b53_srab_priv *priv = dev->priv;
 	u8 __iomem *regs = priv->regs;
 	int i;
 	u32 cmdstat;

 	/* set register address */
 	cmdstat = (page << B53_SRAB_CMDSTAT_PAGE) |
 		  (reg << B53_SRAB_CMDSTAT_REG) |
 		  B53_SRAB_CMDSTAT_GORDYN |
 		  op;
 	writel(cmdstat, regs + B53_SRAB_CMDSTAT);

 	/* check if operation completed */
 	for (i = 0; i < 5; ++i) {
 		cmdstat = readl(regs + B53_SRAB_CMDSTAT);
 		if (!(cmdstat & B53_SRAB_CMDSTAT_GORDYN))
 			break;
 		usleep_range(10, 100);
 	}

 	if (WARN_ON(i == 5))
 		return -EIO;

 	return 0;
 }

 static int b53_srab_read8(struct b53_device *dev, u8 page, u8 reg, u8 *val)
 {
 	struct b53_srab_priv *priv = dev->priv;
 	u8 __iomem *regs = priv->regs;
 	int ret = 0;

 	ret = b53_srab_request_grant(dev);
 	if (ret)
 		goto err;

 	ret = b53_srab_op(dev, page, reg, 0);
 	if (ret)
 		goto err;

 	*val = readl(regs + B53_SRAB_RD_L) & 0xff;

 err:
 	b53_srab_release_grant(dev);

 	return ret;
 }

 static int b53_srab_read16(struct b53_device *dev, u8 page, u8 reg, u16 *val)
 {
 	struct b53_srab_priv *priv = dev->priv;
 	u8 __iomem *regs = priv->regs;
 	int ret = 0;

 	ret = b53_srab_request_grant(dev);
 	if (ret)
 		goto err;

 	ret = b53_srab_op(dev, page, reg, 0);
 	if (ret)
 		goto err;

 	*val = readl(regs + B53_SRAB_RD_L) & 0xffff;

 err:
 	b53_srab_release_grant(dev);

 	return ret;
 }

 static int b53_srab_read32(struct b53_device *dev, u8 page, u8 reg, u32 *val)
 {
 	struct b53_srab_priv *priv = dev->priv;
 	u8 __iomem *regs = priv->regs;
 	int ret = 0;

 	ret = b53_srab_request_grant(dev);
 	if (ret)
 		goto err;

 	ret = b53_srab_op(dev, page, reg, 0);
 	if (ret)
 		goto err;

 	*val = readl(regs + B53_SRAB_RD_L);

 err:
 	b53_srab_release_grant(dev);

 	return ret;
 }

 static int b53_srab_read48(struct b53_device *dev, u8 page, u8 reg, u64 *val)
 {
 	struct b53_srab_priv *priv = dev->priv;
 	u8 __iomem *regs = priv->regs;
 	int ret = 0;

 	ret = b53_srab_request_grant(dev);
 	if (ret)
 		goto err;

 	ret = b53_srab_op(dev, page, reg, 0);
 	if (ret)
 		goto err;

 	*val = readl(regs + B53_SRAB_RD_L);
 	*val += ((u64)readl(regs + B53_SRAB_RD_H) & 0xffff) << 32;

 err:
 	b53_srab_release_grant(dev);

 	return ret;
 }

 static int b53_srab_read64(struct b53_device *dev, u8 page, u8 reg, u64 *val)
 {
 	struct b53_srab_priv *priv = dev->priv;
 	u8 __iomem *regs = priv->regs;
 	int ret = 0;

 	ret = b53_srab_request_grant(dev);
 	if (ret)
 		goto err;

 	ret = b53_srab_op(dev, page, reg, 0);
 	if (ret)
 		goto err;

 	*val = readl(regs + B53_SRAB_RD_L);
 	*val += (u64)readl(regs + B53_SRAB_RD_H) << 32;

 err:
 	b53_srab_release_grant(dev);

 	return ret;
 }

 static int b53_srab_write8(struct b53_device *dev, u8 page, u8 reg, u8 value)
 {
 	struct b53_srab_priv *priv = dev->priv;
 	u8 __iomem *regs = priv->regs;
 	int ret = 0;

 	ret = b53_srab_request_grant(dev);
 	if (ret)
 		goto err;

 	writel(value, regs + B53_SRAB_WD_L);

 	ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);

 err:
 	b53_srab_release_grant(dev);

 	return ret;
 }

 static int b53_srab_write16(struct b53_device *dev, u8 page, u8 reg,
 			    u16 value)
 {
 	struct b53_srab_priv *priv = dev->priv;
 	u8 __iomem *regs = priv->regs;
 	int ret = 0;

 	ret = b53_srab_request_grant(dev);
 	if (ret)
 		goto err;

 	writel(value, regs + B53_SRAB_WD_L);

 	ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);

 err:
 	b53_srab_release_grant(dev);

 	return ret;
 }

 static int b53_srab_write32(struct b53_device *dev, u8 page, u8 reg,
 			    u32 value)
 {
 	struct b53_srab_priv *priv = dev->priv;
 	u8 __iomem *regs = priv->regs;
 	int ret = 0;

 	ret = b53_srab_request_grant(dev);
 	if (ret)
 		goto err;

 	writel(value, regs + B53_SRAB_WD_L);

 	ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);

 err:
 	b53_srab_release_grant(dev);

 	return ret;
 }

 static int b53_srab_write48(struct b53_device *dev, u8 page, u8 reg,
 			    u64 value)
 {
 	struct b53_srab_priv *priv = dev->priv;
 	u8 __iomem *regs = priv->regs;
 	int ret = 0;

 	ret = b53_srab_request_grant(dev);
 	if (ret)
 		goto err;

 	writel((u32)value, regs + B53_SRAB_WD_L);
 	writel((u16)(value >> 32), regs + B53_SRAB_WD_H);

 	ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);

 err:
 	b53_srab_release_grant(dev);

 	return ret;
 }

 static int b53_srab_write64(struct b53_device *dev, u8 page, u8 reg,
 			    u64 value)
 {
 	struct b53_srab_priv *priv = dev->priv;
 	u8 __iomem *regs = priv->regs;
 	int ret = 0;

 	ret = b53_srab_request_grant(dev);
 	if (ret)
 		goto err;

 	writel((u32)value, regs + B53_SRAB_WD_L);
 	writel((u32)(value >> 32), regs + B53_SRAB_WD_H);

 	ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);

 err:
 	b53_srab_release_grant(dev);

 	return ret;
 }

 static const struct b53_io_ops b53_srab_ops = {
 	.read8 = b53_srab_read8,
 	.read16 = b53_srab_read16,
 	.read32 = b53_srab_read32,
 	.read48 = b53_srab_read48,
 	.read64 = b53_srab_read64,
 	.write8 = b53_srab_write8,
 	.write16 = b53_srab_write16,
 	.write32 = b53_srab_write32,
 	.write48 = b53_srab_write48,
 	.write64 = b53_srab_write64,
 };

 static const struct of_device_id b53_srab_of_match[] = {
 	{ .compatible = "brcm,bcm53010-srab" },
 	{ .compatible = "brcm,bcm53011-srab" },
 	{ .compatible = "brcm,bcm53012-srab" },
 	{ .compatible = "brcm,bcm53018-srab" },
 	{ .compatible = "brcm,bcm53019-srab" },
 	{ .compatible = "brcm,bcm5301x-srab" },
 	{ .compatible = "brcm,bcm11360-srab", .data = (void *)BCM583XX_DEVICE_ID },
 	{ .compatible = "brcm,bcm58522-srab", .data = (void *)BCM58XX_DEVICE_ID },
 	{ .compatible = "brcm,bcm58525-srab", .data = (void *)BCM58XX_DEVICE_ID },
 	{ .compatible = "brcm,bcm58535-srab", .data = (void *)BCM58XX_DEVICE_ID },
 	{ .compatible = "brcm,bcm58622-srab", .data = (void *)BCM58XX_DEVICE_ID },
 	{ .compatible = "brcm,bcm58623-srab", .data = (void *)BCM58XX_DEVICE_ID },
 	{ .compatible = "brcm,bcm58625-srab", .data = (void *)BCM58XX_DEVICE_ID },
 	{ .compatible = "brcm,bcm88312-srab", .data = (void *)BCM58XX_DEVICE_ID },
 	{ .compatible = "brcm,cygnus-srab", .data = (void *)BCM583XX_DEVICE_ID },
 	{ .compatible = "brcm,nsp-srab", .data = (void *)BCM58XX_DEVICE_ID },
 	{ .compatible = "brcm,omega-srab", .data = (void *)BCM583XX_DEVICE_ID },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, b53_srab_of_match);

 static int b53_srab_probe(struct platform_device *pdev)
 {
 	struct b53_platform_data *pdata = pdev->dev.platform_data;
 	struct device_node *dn = pdev->dev.of_node;
 	const struct of_device_id *of_id = NULL;
 	struct b53_srab_priv *priv;
 	struct b53_device *dev;
 	struct resource *r;

 	if (dn)
 		of_id = of_match_node(b53_srab_of_match, dn);

 	if (of_id) {
 		pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 		if (!pdata)
 			return -ENOMEM;

 		pdata->chip_id = (u32)(unsigned long)of_id->data;
 	}

 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;

 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	priv->regs = devm_ioremap_resource(&pdev->dev, r);
 	if (IS_ERR(priv->regs))
 		return -ENOMEM;

 	dev = b53_switch_alloc(&pdev->dev, &b53_srab_ops, priv);
 	if (!dev)
 		return -ENOMEM;

 	if (pdata)
 		dev->pdata = pdata;

 	platform_set_drvdata(pdev, dev);

 	return b53_switch_register(dev);
 }

 static int b53_srab_remove(struct platform_device *pdev)
 {
 	struct b53_device *dev = platform_get_drvdata(pdev);

 	if (dev)
 		b53_switch_remove(dev);

 	return 0;
 }

 static struct platform_driver b53_srab_driver = {
 	.probe = b53_srab_probe,
 	.remove = b53_srab_remove,
 	.driver = {
 		.name = "b53-srab-switch",
 		.of_match_table = b53_srab_of_match,
 	},
 };

 module_platform_driver(b53_srab_driver);
 MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
 MODULE_DESCRIPTION("B53 Switch Register Access Bridge Registers (SRAB) access driver");
 MODULE_LICENSE("Dual BSD/GPL");
	/*
	* B53 register access through Switch Register Access Bridge Registers
	*
	* Copyright (C) 2013 Hauke Mehrtens <hauke@hauke-m.de>
	*
	* Permission to use, copy, modify, and/or distribute this software for any
	* purpose with or without fee is hereby granted, provided that the above
	* copyright notice and this permission notice appear in all copies.
	*
	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
	* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/delay.h>
	#include <linux/platform_device.h>
	#include <linux/platform_data/b53.h>
	#include <linux/of.h>

	#include "b53_priv.h"

	/* command and status register of the SRAB */
	#define B53_SRAB_CMDSTAT 0x2c
	#define B53_SRAB_CMDSTAT_RST BIT(2)
	#define B53_SRAB_CMDSTAT_WRITE BIT(1)
	#define B53_SRAB_CMDSTAT_GORDYN BIT(0)
	#define B53_SRAB_CMDSTAT_PAGE 24
	#define B53_SRAB_CMDSTAT_REG 16

	/* high order word of write data to switch registe */
	#define B53_SRAB_WD_H 0x30

	/* low order word of write data to switch registe */
	#define B53_SRAB_WD_L 0x34

	/* high order word of read data from switch register */
	#define B53_SRAB_RD_H 0x38

	/* low order word of read data from switch register */
	#define B53_SRAB_RD_L 0x3c

	/* command and status register of the SRAB */
	#define B53_SRAB_CTRLS 0x40
	#define B53_SRAB_CTRLS_RCAREQ BIT(3)
	#define B53_SRAB_CTRLS_RCAGNT BIT(4)
	#define B53_SRAB_CTRLS_SW_INIT_DONE BIT(6)

	/* the register captures interrupt pulses from the switch */
	#define B53_SRAB_INTR 0x44
	#define B53_SRAB_INTR_P(x) BIT(x)
	#define B53_SRAB_SWITCH_PHY BIT(8)
	#define B53_SRAB_1588_SYNC BIT(9)
	#define B53_SRAB_IMP1_SLEEP_TIMER BIT(10)
	#define B53_SRAB_P7_SLEEP_TIMER BIT(11)
	#define B53_SRAB_IMP0_SLEEP_TIMER BIT(12)

	struct b53_srab_priv {
	void __iomem *regs;
	};

	static int b53_srab_request_grant(struct b53_device *dev)
	{
	struct b53_srab_priv *priv = dev->priv;
	u8 __iomem *regs = priv->regs;
	u32 ctrls;
	int i;

	ctrls = readl(regs + B53_SRAB_CTRLS);
	ctrls \|= B53_SRAB_CTRLS_RCAREQ;
	writel(ctrls, regs + B53_SRAB_CTRLS);

	for (i = 0; i < 20; i++) {
	ctrls = readl(regs + B53_SRAB_CTRLS);
	if (ctrls & B53_SRAB_CTRLS_RCAGNT)
	break;
	usleep_range(10, 100);
	}
	if (WARN_ON(i == 5))
	return -EIO;

	return 0;
	}

	static void b53_srab_release_grant(struct b53_device *dev)
	{
	struct b53_srab_priv *priv = dev->priv;
	u8 __iomem *regs = priv->regs;
	u32 ctrls;

	ctrls = readl(regs + B53_SRAB_CTRLS);
	ctrls &= ~B53_SRAB_CTRLS_RCAREQ;
	writel(ctrls, regs + B53_SRAB_CTRLS);
	}

	static int b53_srab_op(struct b53_device *dev, u8 page, u8 reg, u32 op)
	{
	struct b53_srab_priv *priv = dev->priv;
	u8 __iomem *regs = priv->regs;
	int i;
	u32 cmdstat;

	/* set register address */
	cmdstat = (page << B53_SRAB_CMDSTAT_PAGE) \|
	(reg << B53_SRAB_CMDSTAT_REG) \|
	B53_SRAB_CMDSTAT_GORDYN \|
	op;
	writel(cmdstat, regs + B53_SRAB_CMDSTAT);

	/* check if operation completed */
	for (i = 0; i < 5; ++i) {
	cmdstat = readl(regs + B53_SRAB_CMDSTAT);
	if (!(cmdstat & B53_SRAB_CMDSTAT_GORDYN))
	break;
	usleep_range(10, 100);
	}

	if (WARN_ON(i == 5))
	return -EIO;

	return 0;
	}

	static int b53_srab_read8(struct b53_device dev, u8 page, u8 reg, u8 val)
	{
	struct b53_srab_priv *priv = dev->priv;
	u8 __iomem *regs = priv->regs;
	int ret = 0;

	ret = b53_srab_request_grant(dev);
	if (ret)
	goto err;

	ret = b53_srab_op(dev, page, reg, 0);
	if (ret)
	goto err;

	*val = readl(regs + B53_SRAB_RD_L) & 0xff;

	err:
	b53_srab_release_grant(dev);

	return ret;
	}

	static int b53_srab_read16(struct b53_device dev, u8 page, u8 reg, u16 val)
	{
	struct b53_srab_priv *priv = dev->priv;
	u8 __iomem *regs = priv->regs;
	int ret = 0;

	ret = b53_srab_request_grant(dev);
	if (ret)
	goto err;

	ret = b53_srab_op(dev, page, reg, 0);
	if (ret)
	goto err;

	*val = readl(regs + B53_SRAB_RD_L) & 0xffff;

	err:
	b53_srab_release_grant(dev);

	return ret;
	}

	static int b53_srab_read32(struct b53_device dev, u8 page, u8 reg, u32 val)
	{
	struct b53_srab_priv *priv = dev->priv;
	u8 __iomem *regs = priv->regs;
	int ret = 0;

	ret = b53_srab_request_grant(dev);
	if (ret)
	goto err;

	ret = b53_srab_op(dev, page, reg, 0);
	if (ret)
	goto err;

	*val = readl(regs + B53_SRAB_RD_L);

	err:
	b53_srab_release_grant(dev);

	return ret;
	}

	static int b53_srab_read48(struct b53_device dev, u8 page, u8 reg, u64 val)
	{
	struct b53_srab_priv *priv = dev->priv;
	u8 __iomem *regs = priv->regs;
	int ret = 0;

	ret = b53_srab_request_grant(dev);
	if (ret)
	goto err;

	ret = b53_srab_op(dev, page, reg, 0);
	if (ret)
	goto err;

	*val = readl(regs + B53_SRAB_RD_L);
	*val += ((u64)readl(regs + B53_SRAB_RD_H) & 0xffff) << 32;

	err:
	b53_srab_release_grant(dev);

	return ret;
	}

	static int b53_srab_read64(struct b53_device dev, u8 page, u8 reg, u64 val)
	{
	struct b53_srab_priv *priv = dev->priv;
	u8 __iomem *regs = priv->regs;
	int ret = 0;

	ret = b53_srab_request_grant(dev);
	if (ret)
	goto err;

	ret = b53_srab_op(dev, page, reg, 0);
	if (ret)
	goto err;

	*val = readl(regs + B53_SRAB_RD_L);
	*val += (u64)readl(regs + B53_SRAB_RD_H) << 32;

	err:
	b53_srab_release_grant(dev);

	return ret;
	}

	static int b53_srab_write8(struct b53_device *dev, u8 page, u8 reg, u8 value)
	{
	struct b53_srab_priv *priv = dev->priv;
	u8 __iomem *regs = priv->regs;
	int ret = 0;

	ret = b53_srab_request_grant(dev);
	if (ret)
	goto err;

	writel(value, regs + B53_SRAB_WD_L);

	ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);

	err:
	b53_srab_release_grant(dev);

	return ret;
	}

	static int b53_srab_write16(struct b53_device *dev, u8 page, u8 reg,
	u16 value)
	{
	struct b53_srab_priv *priv = dev->priv;
	u8 __iomem *regs = priv->regs;
	int ret = 0;

	ret = b53_srab_request_grant(dev);
	if (ret)
	goto err;

	writel(value, regs + B53_SRAB_WD_L);

	ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);

	err:
	b53_srab_release_grant(dev);

	return ret;
	}

	static int b53_srab_write32(struct b53_device *dev, u8 page, u8 reg,
	u32 value)
	{
	struct b53_srab_priv *priv = dev->priv;
	u8 __iomem *regs = priv->regs;
	int ret = 0;

	ret = b53_srab_request_grant(dev);
	if (ret)
	goto err;

	writel(value, regs + B53_SRAB_WD_L);

	ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);

	err:
	b53_srab_release_grant(dev);

	return ret;
	}

	static int b53_srab_write48(struct b53_device *dev, u8 page, u8 reg,
	u64 value)
	{
	struct b53_srab_priv *priv = dev->priv;
	u8 __iomem *regs = priv->regs;
	int ret = 0;

	ret = b53_srab_request_grant(dev);
	if (ret)
	goto err;

	writel((u32)value, regs + B53_SRAB_WD_L);
	writel((u16)(value >> 32), regs + B53_SRAB_WD_H);

	ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);

	err:
	b53_srab_release_grant(dev);

	return ret;
	}

	static int b53_srab_write64(struct b53_device *dev, u8 page, u8 reg,
	u64 value)
	{
	struct b53_srab_priv *priv = dev->priv;
	u8 __iomem *regs = priv->regs;
	int ret = 0;

	ret = b53_srab_request_grant(dev);
	if (ret)
	goto err;

	writel((u32)value, regs + B53_SRAB_WD_L);
	writel((u32)(value >> 32), regs + B53_SRAB_WD_H);

	ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);

	err:
	b53_srab_release_grant(dev);

	return ret;
	}

	static const struct b53_io_ops b53_srab_ops = {
	.read8 = b53_srab_read8,
	.read16 = b53_srab_read16,
	.read32 = b53_srab_read32,
	.read48 = b53_srab_read48,
	.read64 = b53_srab_read64,
	.write8 = b53_srab_write8,
	.write16 = b53_srab_write16,
	.write32 = b53_srab_write32,
	.write48 = b53_srab_write48,
	.write64 = b53_srab_write64,
	};

	static const struct of_device_id b53_srab_of_match[] = {
	{ .compatible = "brcm,bcm53010-srab" },
	{ .compatible = "brcm,bcm53011-srab" },
	{ .compatible = "brcm,bcm53012-srab" },
	{ .compatible = "brcm,bcm53018-srab" },
	{ .compatible = "brcm,bcm53019-srab" },
	{ .compatible = "brcm,bcm5301x-srab" },
	{ .compatible = "brcm,bcm11360-srab", .data = (void *)BCM583XX_DEVICE_ID },
	{ .compatible = "brcm,bcm58522-srab", .data = (void *)BCM58XX_DEVICE_ID },
	{ .compatible = "brcm,bcm58525-srab", .data = (void *)BCM58XX_DEVICE_ID },
	{ .compatible = "brcm,bcm58535-srab", .data = (void *)BCM58XX_DEVICE_ID },
	{ .compatible = "brcm,bcm58622-srab", .data = (void *)BCM58XX_DEVICE_ID },
	{ .compatible = "brcm,bcm58623-srab", .data = (void *)BCM58XX_DEVICE_ID },
	{ .compatible = "brcm,bcm58625-srab", .data = (void *)BCM58XX_DEVICE_ID },
	{ .compatible = "brcm,bcm88312-srab", .data = (void *)BCM58XX_DEVICE_ID },
	{ .compatible = "brcm,cygnus-srab", .data = (void *)BCM583XX_DEVICE_ID },
	{ .compatible = "brcm,nsp-srab", .data = (void *)BCM58XX_DEVICE_ID },
	{ .compatible = "brcm,omega-srab", .data = (void *)BCM583XX_DEVICE_ID },
	{ /* sentinel */ },
	};
	MODULE_DEVICE_TABLE(of, b53_srab_of_match);

	static int b53_srab_probe(struct platform_device *pdev)
	{
	struct b53_platform_data *pdata = pdev->dev.platform_data;
	struct device_node *dn = pdev->dev.of_node;
	const struct of_device_id *of_id = NULL;
	struct b53_srab_priv *priv;
	struct b53_device *dev;
	struct resource *r;

	if (dn)
	of_id = of_match_node(b53_srab_of_match, dn);

	if (of_id) {
	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
	return -ENOMEM;

	pdata->chip_id = (u32)(unsigned long)of_id->data;
	}

	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
	return -ENOMEM;

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	priv->regs = devm_ioremap_resource(&pdev->dev, r);
	if (IS_ERR(priv->regs))
	return -ENOMEM;

	dev = b53_switch_alloc(&pdev->dev, &b53_srab_ops, priv);
	if (!dev)
	return -ENOMEM;

	if (pdata)
	dev->pdata = pdata;

	platform_set_drvdata(pdev, dev);

	return b53_switch_register(dev);
	}

	static int b53_srab_remove(struct platform_device *pdev)
	{
	struct b53_device *dev = platform_get_drvdata(pdev);

	if (dev)
	b53_switch_remove(dev);

	return 0;
	}

	static struct platform_driver b53_srab_driver = {
	.probe = b53_srab_probe,
	.remove = b53_srab_remove,
	.driver = {
	.name = "b53-srab-switch",
	.of_match_table = b53_srab_of_match,
	},
	};

	module_platform_driver(b53_srab_driver);
	MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
	MODULE_DESCRIPTION("B53 Switch Register Access Bridge Registers (SRAB) access driver");
	MODULE_LICENSE("Dual BSD/GPL");