drivers/net/dsa/b53/b53_spi.c - linux/kernel/git/bpf/bpf-next - Git at Google

 /*
  * B53 register access through SPI
  *
  * Copyright (C) 2011-2013 Jonas Gorski <jogo@openwrt.org>
  *
  * 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 <asm/unaligned.h>

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

 #include "b53_priv.h"

 #define B53_SPI_DATA		0xf0

 #define B53_SPI_STATUS		0xfe
 #define B53_SPI_CMD_SPIF	BIT(7)
 #define B53_SPI_CMD_RACK	BIT(5)

 #define B53_SPI_CMD_READ	0x00
 #define B53_SPI_CMD_WRITE	0x01
 #define B53_SPI_CMD_NORMAL	0x60
 #define B53_SPI_CMD_FAST	0x10

 #define B53_SPI_PAGE_SELECT	0xff

 static inline int b53_spi_read_reg(struct spi_device *spi, u8 reg, u8 *val,
 				   unsigned int len)
 {
 	u8 txbuf[2];

 	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_READ;
 	txbuf[1] = reg;

 	return spi_write_then_read(spi, txbuf, 2, val, len);
 }

 static inline int b53_spi_clear_status(struct spi_device *spi)
 {
 	unsigned int i;
 	u8 rxbuf;
 	int ret;

 	for (i = 0; i < 10; i++) {
 		ret = b53_spi_read_reg(spi, B53_SPI_STATUS, &rxbuf, 1);
 		if (ret)
 			return ret;

 		if (!(rxbuf & B53_SPI_CMD_SPIF))
 			break;

 		mdelay(1);
 	}

 	if (i == 10)
 		return -EIO;

 	return 0;
 }

 static inline int b53_spi_set_page(struct spi_device *spi, u8 page)
 {
 	u8 txbuf[3];

 	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 	txbuf[1] = B53_SPI_PAGE_SELECT;
 	txbuf[2] = page;

 	return spi_write(spi, txbuf, sizeof(txbuf));
 }

 static inline int b53_prepare_reg_access(struct spi_device *spi, u8 page)
 {
 	int ret = b53_spi_clear_status(spi);

 	if (ret)
 		return ret;

 	return b53_spi_set_page(spi, page);
 }

 static int b53_spi_prepare_reg_read(struct spi_device *spi, u8 reg)
 {
 	u8 rxbuf;
 	int retry_count;
 	int ret;

 	ret = b53_spi_read_reg(spi, reg, &rxbuf, 1);
 	if (ret)
 		return ret;

 	for (retry_count = 0; retry_count < 10; retry_count++) {
 		ret = b53_spi_read_reg(spi, B53_SPI_STATUS, &rxbuf, 1);
 		if (ret)
 			return ret;

 		if (rxbuf & B53_SPI_CMD_RACK)
 			break;

 		mdelay(1);
 	}

 	if (retry_count == 10)
 		return -EIO;

 	return 0;
 }

 static int b53_spi_read(struct b53_device *dev, u8 page, u8 reg, u8 *data,
 			unsigned int len)
 {
 	struct spi_device *spi = dev->priv;
 	int ret;

 	ret = b53_prepare_reg_access(spi, page);
 	if (ret)
 		return ret;

 	ret = b53_spi_prepare_reg_read(spi, reg);
 	if (ret)
 		return ret;

 	return b53_spi_read_reg(spi, B53_SPI_DATA, data, len);
 }

 static int b53_spi_read8(struct b53_device *dev, u8 page, u8 reg, u8 *val)
 {
 	return b53_spi_read(dev, page, reg, val, 1);
 }

 static int b53_spi_read16(struct b53_device *dev, u8 page, u8 reg, u16 *val)
 {
 	int ret = b53_spi_read(dev, page, reg, (u8 *)val, 2);

 	if (!ret)
 		*val = le16_to_cpu(*val);

 	return ret;
 }

 static int b53_spi_read32(struct b53_device *dev, u8 page, u8 reg, u32 *val)
 {
 	int ret = b53_spi_read(dev, page, reg, (u8 *)val, 4);

 	if (!ret)
 		*val = le32_to_cpu(*val);

 	return ret;
 }

 static int b53_spi_read48(struct b53_device *dev, u8 page, u8 reg, u64 *val)
 {
 	int ret;

 	*val = 0;
 	ret = b53_spi_read(dev, page, reg, (u8 *)val, 6);
 	if (!ret)
 		*val = le64_to_cpu(*val);

 	return ret;
 }

 static int b53_spi_read64(struct b53_device *dev, u8 page, u8 reg, u64 *val)
 {
 	int ret = b53_spi_read(dev, page, reg, (u8 *)val, 8);

 	if (!ret)
 		*val = le64_to_cpu(*val);

 	return ret;
 }

 static int b53_spi_write8(struct b53_device *dev, u8 page, u8 reg, u8 value)
 {
 	struct spi_device *spi = dev->priv;
 	int ret;
 	u8 txbuf[3];

 	ret = b53_prepare_reg_access(spi, page);
 	if (ret)
 		return ret;

 	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 	txbuf[1] = reg;
 	txbuf[2] = value;

 	return spi_write(spi, txbuf, sizeof(txbuf));
 }

 static int b53_spi_write16(struct b53_device *dev, u8 page, u8 reg, u16 value)
 {
 	struct spi_device *spi = dev->priv;
 	int ret;
 	u8 txbuf[4];

 	ret = b53_prepare_reg_access(spi, page);
 	if (ret)
 		return ret;

 	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 	txbuf[1] = reg;
 	put_unaligned_le16(value, &txbuf[2]);

 	return spi_write(spi, txbuf, sizeof(txbuf));
 }

 static int b53_spi_write32(struct b53_device *dev, u8 page, u8 reg, u32 value)
 {
 	struct spi_device *spi = dev->priv;
 	int ret;
 	u8 txbuf[6];

 	ret = b53_prepare_reg_access(spi, page);
 	if (ret)
 		return ret;

 	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 	txbuf[1] = reg;
 	put_unaligned_le32(value, &txbuf[2]);

 	return spi_write(spi, txbuf, sizeof(txbuf));
 }

 static int b53_spi_write48(struct b53_device *dev, u8 page, u8 reg, u64 value)
 {
 	struct spi_device *spi = dev->priv;
 	int ret;
 	u8 txbuf[10];

 	ret = b53_prepare_reg_access(spi, page);
 	if (ret)
 		return ret;

 	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 	txbuf[1] = reg;
 	put_unaligned_le64(value, &txbuf[2]);

 	return spi_write(spi, txbuf, sizeof(txbuf) - 2);
 }

 static int b53_spi_write64(struct b53_device *dev, u8 page, u8 reg, u64 value)
 {
 	struct spi_device *spi = dev->priv;
 	int ret;
 	u8 txbuf[10];

 	ret = b53_prepare_reg_access(spi, page);
 	if (ret)
 		return ret;

 	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 	txbuf[1] = reg;
 	put_unaligned_le64(value, &txbuf[2]);

 	return spi_write(spi, txbuf, sizeof(txbuf));
 }

 static const struct b53_io_ops b53_spi_ops = {
 	.read8 = b53_spi_read8,
 	.read16 = b53_spi_read16,
 	.read32 = b53_spi_read32,
 	.read48 = b53_spi_read48,
 	.read64 = b53_spi_read64,
 	.write8 = b53_spi_write8,
 	.write16 = b53_spi_write16,
 	.write32 = b53_spi_write32,
 	.write48 = b53_spi_write48,
 	.write64 = b53_spi_write64,
 };

 static int b53_spi_probe(struct spi_device *spi)
 {
 	struct b53_device *dev;
 	int ret;

 	dev = b53_switch_alloc(&spi->dev, &b53_spi_ops, spi);
 	if (!dev)
 		return -ENOMEM;

 	if (spi->dev.platform_data)
 		dev->pdata = spi->dev.platform_data;

 	ret = b53_switch_register(dev);
 	if (ret)
 		return ret;

 	spi_set_drvdata(spi, dev);

 	return 0;
 }

 static int b53_spi_remove(struct spi_device *spi)
 {
 	struct b53_device *dev = spi_get_drvdata(spi);

 	if (dev)
 		b53_switch_remove(dev);

 	return 0;
 }

 static struct spi_driver b53_spi_driver = {
 	.driver = {
 		.name	= "b53-switch",
 	},
 	.probe	= b53_spi_probe,
 	.remove	= b53_spi_remove,
 };

 module_spi_driver(b53_spi_driver);

 MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
 MODULE_DESCRIPTION("B53 SPI access driver");
 MODULE_LICENSE("Dual BSD/GPL");
	/*
	* B53 register access through SPI
	*
	* Copyright (C) 2011-2013 Jonas Gorski <jogo@openwrt.org>
	*
	* 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 <asm/unaligned.h>

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

	#include "b53_priv.h"

	#define B53_SPI_DATA 0xf0

	#define B53_SPI_STATUS 0xfe
	#define B53_SPI_CMD_SPIF BIT(7)
	#define B53_SPI_CMD_RACK BIT(5)

	#define B53_SPI_CMD_READ 0x00
	#define B53_SPI_CMD_WRITE 0x01
	#define B53_SPI_CMD_NORMAL 0x60
	#define B53_SPI_CMD_FAST 0x10

	#define B53_SPI_PAGE_SELECT 0xff

	static inline int b53_spi_read_reg(struct spi_device spi, u8 reg, u8 val,
	unsigned int len)
	{
	u8 txbuf[2];

	txbuf[0] = B53_SPI_CMD_NORMAL \| B53_SPI_CMD_READ;
	txbuf[1] = reg;

	return spi_write_then_read(spi, txbuf, 2, val, len);
	}

	static inline int b53_spi_clear_status(struct spi_device *spi)
	{
	unsigned int i;
	u8 rxbuf;
	int ret;

	for (i = 0; i < 10; i++) {
	ret = b53_spi_read_reg(spi, B53_SPI_STATUS, &rxbuf, 1);
	if (ret)
	return ret;

	if (!(rxbuf & B53_SPI_CMD_SPIF))
	break;

	mdelay(1);
	}

	if (i == 10)
	return -EIO;

	return 0;
	}

	static inline int b53_spi_set_page(struct spi_device *spi, u8 page)
	{
	u8 txbuf[3];

	txbuf[0] = B53_SPI_CMD_NORMAL \| B53_SPI_CMD_WRITE;
	txbuf[1] = B53_SPI_PAGE_SELECT;
	txbuf[2] = page;

	return spi_write(spi, txbuf, sizeof(txbuf));
	}

	static inline int b53_prepare_reg_access(struct spi_device *spi, u8 page)
	{
	int ret = b53_spi_clear_status(spi);

	if (ret)
	return ret;

	return b53_spi_set_page(spi, page);
	}

	static int b53_spi_prepare_reg_read(struct spi_device *spi, u8 reg)
	{
	u8 rxbuf;
	int retry_count;
	int ret;

	ret = b53_spi_read_reg(spi, reg, &rxbuf, 1);
	if (ret)
	return ret;

	for (retry_count = 0; retry_count < 10; retry_count++) {
	ret = b53_spi_read_reg(spi, B53_SPI_STATUS, &rxbuf, 1);
	if (ret)
	return ret;

	if (rxbuf & B53_SPI_CMD_RACK)
	break;

	mdelay(1);
	}

	if (retry_count == 10)
	return -EIO;

	return 0;
	}

	static int b53_spi_read(struct b53_device dev, u8 page, u8 reg, u8 data,
	unsigned int len)
	{
	struct spi_device *spi = dev->priv;
	int ret;

	ret = b53_prepare_reg_access(spi, page);
	if (ret)
	return ret;

	ret = b53_spi_prepare_reg_read(spi, reg);
	if (ret)
	return ret;

	return b53_spi_read_reg(spi, B53_SPI_DATA, data, len);
	}

	static int b53_spi_read8(struct b53_device dev, u8 page, u8 reg, u8 val)
	{
	return b53_spi_read(dev, page, reg, val, 1);
	}

	static int b53_spi_read16(struct b53_device dev, u8 page, u8 reg, u16 val)
	{
	int ret = b53_spi_read(dev, page, reg, (u8 *)val, 2);

	if (!ret)
	val = le16_to_cpu(val);

	return ret;
	}

	static int b53_spi_read32(struct b53_device dev, u8 page, u8 reg, u32 val)
	{
	int ret = b53_spi_read(dev, page, reg, (u8 *)val, 4);

	if (!ret)
	val = le32_to_cpu(val);

	return ret;
	}

	static int b53_spi_read48(struct b53_device dev, u8 page, u8 reg, u64 val)
	{
	int ret;

	*val = 0;
	ret = b53_spi_read(dev, page, reg, (u8 *)val, 6);
	if (!ret)
	val = le64_to_cpu(val);

	return ret;
	}

	static int b53_spi_read64(struct b53_device dev, u8 page, u8 reg, u64 val)
	{
	int ret = b53_spi_read(dev, page, reg, (u8 *)val, 8);

	if (!ret)
	val = le64_to_cpu(val);

	return ret;
	}

	static int b53_spi_write8(struct b53_device *dev, u8 page, u8 reg, u8 value)
	{
	struct spi_device *spi = dev->priv;
	int ret;
	u8 txbuf[3];

	ret = b53_prepare_reg_access(spi, page);
	if (ret)
	return ret;

	txbuf[0] = B53_SPI_CMD_NORMAL \| B53_SPI_CMD_WRITE;
	txbuf[1] = reg;
	txbuf[2] = value;

	return spi_write(spi, txbuf, sizeof(txbuf));
	}

	static int b53_spi_write16(struct b53_device *dev, u8 page, u8 reg, u16 value)
	{
	struct spi_device *spi = dev->priv;
	int ret;
	u8 txbuf[4];

	ret = b53_prepare_reg_access(spi, page);
	if (ret)
	return ret;

	txbuf[0] = B53_SPI_CMD_NORMAL \| B53_SPI_CMD_WRITE;
	txbuf[1] = reg;
	put_unaligned_le16(value, &txbuf[2]);

	return spi_write(spi, txbuf, sizeof(txbuf));
	}

	static int b53_spi_write32(struct b53_device *dev, u8 page, u8 reg, u32 value)
	{
	struct spi_device *spi = dev->priv;
	int ret;
	u8 txbuf[6];

	ret = b53_prepare_reg_access(spi, page);
	if (ret)
	return ret;

	txbuf[0] = B53_SPI_CMD_NORMAL \| B53_SPI_CMD_WRITE;
	txbuf[1] = reg;
	put_unaligned_le32(value, &txbuf[2]);

	return spi_write(spi, txbuf, sizeof(txbuf));
	}

	static int b53_spi_write48(struct b53_device *dev, u8 page, u8 reg, u64 value)
	{
	struct spi_device *spi = dev->priv;
	int ret;
	u8 txbuf[10];

	ret = b53_prepare_reg_access(spi, page);
	if (ret)
	return ret;

	txbuf[0] = B53_SPI_CMD_NORMAL \| B53_SPI_CMD_WRITE;
	txbuf[1] = reg;
	put_unaligned_le64(value, &txbuf[2]);

	return spi_write(spi, txbuf, sizeof(txbuf) - 2);
	}

	static int b53_spi_write64(struct b53_device *dev, u8 page, u8 reg, u64 value)
	{
	struct spi_device *spi = dev->priv;
	int ret;
	u8 txbuf[10];

	ret = b53_prepare_reg_access(spi, page);
	if (ret)
	return ret;

	txbuf[0] = B53_SPI_CMD_NORMAL \| B53_SPI_CMD_WRITE;
	txbuf[1] = reg;
	put_unaligned_le64(value, &txbuf[2]);

	return spi_write(spi, txbuf, sizeof(txbuf));
	}

	static const struct b53_io_ops b53_spi_ops = {
	.read8 = b53_spi_read8,
	.read16 = b53_spi_read16,
	.read32 = b53_spi_read32,
	.read48 = b53_spi_read48,
	.read64 = b53_spi_read64,
	.write8 = b53_spi_write8,
	.write16 = b53_spi_write16,
	.write32 = b53_spi_write32,
	.write48 = b53_spi_write48,
	.write64 = b53_spi_write64,
	};

	static int b53_spi_probe(struct spi_device *spi)
	{
	struct b53_device *dev;
	int ret;

	dev = b53_switch_alloc(&spi->dev, &b53_spi_ops, spi);
	if (!dev)
	return -ENOMEM;

	if (spi->dev.platform_data)
	dev->pdata = spi->dev.platform_data;

	ret = b53_switch_register(dev);
	if (ret)
	return ret;

	spi_set_drvdata(spi, dev);

	return 0;
	}

	static int b53_spi_remove(struct spi_device *spi)
	{
	struct b53_device *dev = spi_get_drvdata(spi);

	if (dev)
	b53_switch_remove(dev);

	return 0;
	}

	static struct spi_driver b53_spi_driver = {
	.driver = {
	.name = "b53-switch",
	},
	.probe = b53_spi_probe,
	.remove = b53_spi_remove,
	};

	module_spi_driver(b53_spi_driver);

	MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
	MODULE_DESCRIPTION("B53 SPI access driver");
	MODULE_LICENSE("Dual BSD/GPL");