drivers/i2c/busses/i2c-dln2.c - kernel/msm-4.9 - Gitiles

 /*
  * Driver for the Diolan DLN-2 USB-I2C adapter
  *
  * Copyright (c) 2014 Intel Corporation
  *
  * Derived from:
  *  i2c-diolan-u2c.c
  *  Copyright (c) 2010-2011 Ericsson AB
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation, version 2.
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/i2c.h>
 #include <linux/platform_device.h>
 #include <linux/mfd/dln2.h>

 #define DLN2_I2C_MODULE_ID		0x03
 #define DLN2_I2C_CMD(cmd)		DLN2_CMD(cmd, DLN2_I2C_MODULE_ID)

 /* I2C commands */
 #define DLN2_I2C_GET_PORT_COUNT		DLN2_I2C_CMD(0x00)
 #define DLN2_I2C_ENABLE			DLN2_I2C_CMD(0x01)
 #define DLN2_I2C_DISABLE		DLN2_I2C_CMD(0x02)
 #define DLN2_I2C_IS_ENABLED		DLN2_I2C_CMD(0x03)
 #define DLN2_I2C_WRITE			DLN2_I2C_CMD(0x06)
 #define DLN2_I2C_READ			DLN2_I2C_CMD(0x07)
 #define DLN2_I2C_SCAN_DEVICES		DLN2_I2C_CMD(0x08)
 #define DLN2_I2C_PULLUP_ENABLE		DLN2_I2C_CMD(0x09)
 #define DLN2_I2C_PULLUP_DISABLE		DLN2_I2C_CMD(0x0A)
 #define DLN2_I2C_PULLUP_IS_ENABLED	DLN2_I2C_CMD(0x0B)
 #define DLN2_I2C_TRANSFER		DLN2_I2C_CMD(0x0C)
 #define DLN2_I2C_SET_MAX_REPLY_COUNT	DLN2_I2C_CMD(0x0D)
 #define DLN2_I2C_GET_MAX_REPLY_COUNT	DLN2_I2C_CMD(0x0E)

 #define DLN2_I2C_MAX_XFER_SIZE		256
 #define DLN2_I2C_BUF_SIZE		(DLN2_I2C_MAX_XFER_SIZE + 16)

 struct dln2_i2c {
 	struct platform_device *pdev;
 	struct i2c_adapter adapter;
 	u8 port;
 	/*
 	 * Buffer to hold the packet for read or write transfers. One is enough
 	 * since we can't have multiple transfers in parallel on the i2c bus.
 	 */
 	void *buf;
 };

 static int dln2_i2c_enable(struct dln2_i2c *dln2, bool enable)
 {
 	u16 cmd;
 	struct {
 		u8 port;
 	} tx;

 	tx.port = dln2->port;

 	if (enable)
 		cmd = DLN2_I2C_ENABLE;
 	else
 		cmd = DLN2_I2C_DISABLE;

 	return dln2_transfer_tx(dln2->pdev, cmd, &tx, sizeof(tx));
 }

 static int dln2_i2c_write(struct dln2_i2c *dln2, u8 addr,
 			  u8 *data, u16 data_len)
 {
 	int ret;
 	struct {
 		u8 port;
 		u8 addr;
 		u8 mem_addr_len;
 		__le32 mem_addr;
 		__le16 buf_len;
 		u8 buf[DLN2_I2C_MAX_XFER_SIZE];
 	} __packed *tx = dln2->buf;
 	unsigned len;

 	BUILD_BUG_ON(sizeof(*tx) > DLN2_I2C_BUF_SIZE);

 	tx->port = dln2->port;
 	tx->addr = addr;
 	tx->mem_addr_len = 0;
 	tx->mem_addr = 0;
 	tx->buf_len = cpu_to_le16(data_len);
 	memcpy(tx->buf, data, data_len);

 	len = sizeof(*tx) + data_len - DLN2_I2C_MAX_XFER_SIZE;
 	ret = dln2_transfer_tx(dln2->pdev, DLN2_I2C_WRITE, tx, len);
 	if (ret < 0)
 		return ret;

 	return data_len;
 }

 static int dln2_i2c_read(struct dln2_i2c *dln2, u16 addr, u8 *data,
 			 u16 data_len)
 {
 	int ret;
 	struct {
 		u8 port;
 		u8 addr;
 		u8 mem_addr_len;
 		__le32 mem_addr;
 		__le16 buf_len;
 	} __packed tx;
 	struct {
 		__le16 buf_len;
 		u8 buf[DLN2_I2C_MAX_XFER_SIZE];
 	} __packed *rx = dln2->buf;
 	unsigned rx_len = sizeof(*rx);

 	BUILD_BUG_ON(sizeof(*rx) > DLN2_I2C_BUF_SIZE);

 	tx.port = dln2->port;
 	tx.addr = addr;
 	tx.mem_addr_len = 0;
 	tx.mem_addr = 0;
 	tx.buf_len = cpu_to_le16(data_len);

 	ret = dln2_transfer(dln2->pdev, DLN2_I2C_READ, &tx, sizeof(tx),
 			    rx, &rx_len);
 	if (ret < 0)
 		return ret;
 	if (rx_len < sizeof(rx->buf_len) + data_len)
 		return -EPROTO;
 	if (le16_to_cpu(rx->buf_len) != data_len)
 		return -EPROTO;

 	memcpy(data, rx->buf, data_len);

 	return data_len;
 }

 static int dln2_i2c_xfer(struct i2c_adapter *adapter,
 			 struct i2c_msg *msgs, int num)
 {
 	struct dln2_i2c *dln2 = i2c_get_adapdata(adapter);
 	struct i2c_msg *pmsg;
 	struct device *dev = &dln2->adapter.dev;
 	int i;

 	for (i = 0; i < num; i++) {
 		int ret;

 		pmsg = &msgs[i];

 		if (pmsg->len > DLN2_I2C_MAX_XFER_SIZE) {
 			dev_warn(dev, "maximum transfer size exceeded\n");
 			return -EOPNOTSUPP;
 		}

 		if (pmsg->flags & I2C_M_RD) {
 			ret = dln2_i2c_read(dln2, pmsg->addr, pmsg->buf,
 					    pmsg->len);
 			if (ret < 0)
 				return ret;

 			pmsg->len = ret;
 		} else {
 			ret = dln2_i2c_write(dln2, pmsg->addr, pmsg->buf,
 					     pmsg->len);
 			if (ret != pmsg->len)
 				return -EPROTO;
 		}
 	}

 	return num;
 }

 static u32 dln2_i2c_func(struct i2c_adapter *a)
 {
 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA |
 		I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
 		I2C_FUNC_SMBUS_I2C_BLOCK;
 }

 static const struct i2c_algorithm dln2_i2c_usb_algorithm = {
 	.master_xfer = dln2_i2c_xfer,
 	.functionality = dln2_i2c_func,
 };

 static int dln2_i2c_probe(struct platform_device *pdev)
 {
 	int ret;
 	struct dln2_i2c *dln2;
 	struct device *dev = &pdev->dev;
 	struct dln2_platform_data *pdata = dev_get_platdata(&pdev->dev);

 	dln2 = devm_kzalloc(dev, sizeof(*dln2), GFP_KERNEL);
 	if (!dln2)
 		return -ENOMEM;

 	dln2->buf = devm_kmalloc(dev, DLN2_I2C_BUF_SIZE, GFP_KERNEL);
 	if (!dln2->buf)
 		return -ENOMEM;

 	dln2->pdev = pdev;
 	dln2->port = pdata->port;

 	/* setup i2c adapter description */
 	dln2->adapter.owner = THIS_MODULE;
 	dln2->adapter.class = I2C_CLASS_HWMON;
 	dln2->adapter.algo = &dln2_i2c_usb_algorithm;
 	dln2->adapter.dev.parent = dev;
 	i2c_set_adapdata(&dln2->adapter, dln2);
 	snprintf(dln2->adapter.name, sizeof(dln2->adapter.name), "%s-%s-%d",
 		 "dln2-i2c", dev_name(pdev->dev.parent), dln2->port);

 	platform_set_drvdata(pdev, dln2);

 	/* initialize the i2c interface */
 	ret = dln2_i2c_enable(dln2, true);
 	if (ret < 0) {
 		dev_err(dev, "failed to initialize adapter: %d\n", ret);
 		return ret;
 	}

 	/* and finally attach to i2c layer */
 	ret = i2c_add_adapter(&dln2->adapter);
 	if (ret < 0) {
 		dev_err(dev, "failed to add I2C adapter: %d\n", ret);
 		goto out_disable;
 	}

 	return 0;

 out_disable:
 	dln2_i2c_enable(dln2, false);

 	return ret;
 }

 static int dln2_i2c_remove(struct platform_device *pdev)
 {
 	struct dln2_i2c *dln2 = platform_get_drvdata(pdev);

 	i2c_del_adapter(&dln2->adapter);
 	dln2_i2c_enable(dln2, false);

 	return 0;
 }

 static struct platform_driver dln2_i2c_driver = {
 	.driver.name	= "dln2-i2c",
 	.probe		= dln2_i2c_probe,
 	.remove		= dln2_i2c_remove,
 };

 module_platform_driver(dln2_i2c_driver);

 MODULE_AUTHOR("Laurentiu Palcu <laurentiu.palcu@intel.com>");
 MODULE_DESCRIPTION("Driver for the Diolan DLN2 I2C master interface");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("platform:dln2-i2c");
	/*
	* Driver for the Diolan DLN-2 USB-I2C adapter
	*
	* Copyright (c) 2014 Intel Corporation
	*
	* Derived from:
	* i2c-diolan-u2c.c
	* Copyright (c) 2010-2011 Ericsson AB
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License as
	* published by the Free Software Foundation, version 2.
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/slab.h>
	#include <linux/i2c.h>
	#include <linux/platform_device.h>
	#include <linux/mfd/dln2.h>

	#define DLN2_I2C_MODULE_ID 0x03
	#define DLN2_I2C_CMD(cmd) DLN2_CMD(cmd, DLN2_I2C_MODULE_ID)

	/* I2C commands */
	#define DLN2_I2C_GET_PORT_COUNT DLN2_I2C_CMD(0x00)
	#define DLN2_I2C_ENABLE DLN2_I2C_CMD(0x01)
	#define DLN2_I2C_DISABLE DLN2_I2C_CMD(0x02)
	#define DLN2_I2C_IS_ENABLED DLN2_I2C_CMD(0x03)
	#define DLN2_I2C_WRITE DLN2_I2C_CMD(0x06)
	#define DLN2_I2C_READ DLN2_I2C_CMD(0x07)
	#define DLN2_I2C_SCAN_DEVICES DLN2_I2C_CMD(0x08)
	#define DLN2_I2C_PULLUP_ENABLE DLN2_I2C_CMD(0x09)
	#define DLN2_I2C_PULLUP_DISABLE DLN2_I2C_CMD(0x0A)
	#define DLN2_I2C_PULLUP_IS_ENABLED DLN2_I2C_CMD(0x0B)
	#define DLN2_I2C_TRANSFER DLN2_I2C_CMD(0x0C)
	#define DLN2_I2C_SET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0D)
	#define DLN2_I2C_GET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0E)

	#define DLN2_I2C_MAX_XFER_SIZE 256
	#define DLN2_I2C_BUF_SIZE (DLN2_I2C_MAX_XFER_SIZE + 16)

	struct dln2_i2c {
	struct platform_device *pdev;
	struct i2c_adapter adapter;
	u8 port;
	/*
	* Buffer to hold the packet for read or write transfers. One is enough
	* since we can't have multiple transfers in parallel on the i2c bus.
	*/
	void *buf;
	};

	static int dln2_i2c_enable(struct dln2_i2c *dln2, bool enable)
	{
	u16 cmd;
	struct {
	u8 port;
	} tx;

	tx.port = dln2->port;

	if (enable)
	cmd = DLN2_I2C_ENABLE;
	else
	cmd = DLN2_I2C_DISABLE;

	return dln2_transfer_tx(dln2->pdev, cmd, &tx, sizeof(tx));
	}

	static int dln2_i2c_write(struct dln2_i2c *dln2, u8 addr,
	u8 *data, u16 data_len)
	{
	int ret;
	struct {
	u8 port;
	u8 addr;
	u8 mem_addr_len;
	__le32 mem_addr;
	__le16 buf_len;
	u8 buf[DLN2_I2C_MAX_XFER_SIZE];
	} __packed *tx = dln2->buf;
	unsigned len;

	BUILD_BUG_ON(sizeof(*tx) > DLN2_I2C_BUF_SIZE);

	tx->port = dln2->port;
	tx->addr = addr;
	tx->mem_addr_len = 0;
	tx->mem_addr = 0;
	tx->buf_len = cpu_to_le16(data_len);
	memcpy(tx->buf, data, data_len);

	len = sizeof(*tx) + data_len - DLN2_I2C_MAX_XFER_SIZE;
	ret = dln2_transfer_tx(dln2->pdev, DLN2_I2C_WRITE, tx, len);
	if (ret < 0)
	return ret;

	return data_len;
	}

	static int dln2_i2c_read(struct dln2_i2c dln2, u16 addr, u8 data,
	u16 data_len)
	{
	int ret;
	struct {
	u8 port;
	u8 addr;
	u8 mem_addr_len;
	__le32 mem_addr;
	__le16 buf_len;
	} __packed tx;
	struct {
	__le16 buf_len;
	u8 buf[DLN2_I2C_MAX_XFER_SIZE];
	} __packed *rx = dln2->buf;
	unsigned rx_len = sizeof(*rx);

	BUILD_BUG_ON(sizeof(*rx) > DLN2_I2C_BUF_SIZE);

	tx.port = dln2->port;
	tx.addr = addr;
	tx.mem_addr_len = 0;
	tx.mem_addr = 0;
	tx.buf_len = cpu_to_le16(data_len);

	ret = dln2_transfer(dln2->pdev, DLN2_I2C_READ, &tx, sizeof(tx),
	rx, &rx_len);
	if (ret < 0)
	return ret;
	if (rx_len < sizeof(rx->buf_len) + data_len)
	return -EPROTO;
	if (le16_to_cpu(rx->buf_len) != data_len)
	return -EPROTO;

	memcpy(data, rx->buf, data_len);

	return data_len;
	}

	static int dln2_i2c_xfer(struct i2c_adapter *adapter,
	struct i2c_msg *msgs, int num)
	{
	struct dln2_i2c *dln2 = i2c_get_adapdata(adapter);
	struct i2c_msg *pmsg;
	struct device *dev = &dln2->adapter.dev;
	int i;

	for (i = 0; i < num; i++) {
	int ret;

	pmsg = &msgs[i];

	if (pmsg->len > DLN2_I2C_MAX_XFER_SIZE) {
	dev_warn(dev, "maximum transfer size exceeded\n");
	return -EOPNOTSUPP;
	}

	if (pmsg->flags & I2C_M_RD) {
	ret = dln2_i2c_read(dln2, pmsg->addr, pmsg->buf,
	pmsg->len);
	if (ret < 0)
	return ret;

	pmsg->len = ret;
	} else {
	ret = dln2_i2c_write(dln2, pmsg->addr, pmsg->buf,
	pmsg->len);
	if (ret != pmsg->len)
	return -EPROTO;
	}
	}

	return num;
	}

	static u32 dln2_i2c_func(struct i2c_adapter *a)
	{
	return I2C_FUNC_I2C \| I2C_FUNC_SMBUS_BYTE \| I2C_FUNC_SMBUS_BYTE_DATA \|
	I2C_FUNC_SMBUS_WORD_DATA \| I2C_FUNC_SMBUS_BLOCK_PROC_CALL \|
	I2C_FUNC_SMBUS_I2C_BLOCK;
	}

	static const struct i2c_algorithm dln2_i2c_usb_algorithm = {
	.master_xfer = dln2_i2c_xfer,
	.functionality = dln2_i2c_func,
	};

	static int dln2_i2c_probe(struct platform_device *pdev)
	{
	int ret;
	struct dln2_i2c *dln2;
	struct device *dev = &pdev->dev;
	struct dln2_platform_data *pdata = dev_get_platdata(&pdev->dev);

	dln2 = devm_kzalloc(dev, sizeof(*dln2), GFP_KERNEL);
	if (!dln2)
	return -ENOMEM;

	dln2->buf = devm_kmalloc(dev, DLN2_I2C_BUF_SIZE, GFP_KERNEL);
	if (!dln2->buf)
	return -ENOMEM;

	dln2->pdev = pdev;
	dln2->port = pdata->port;

	/* setup i2c adapter description */
	dln2->adapter.owner = THIS_MODULE;
	dln2->adapter.class = I2C_CLASS_HWMON;
	dln2->adapter.algo = &dln2_i2c_usb_algorithm;
	dln2->adapter.dev.parent = dev;
	i2c_set_adapdata(&dln2->adapter, dln2);
	snprintf(dln2->adapter.name, sizeof(dln2->adapter.name), "%s-%s-%d",
	"dln2-i2c", dev_name(pdev->dev.parent), dln2->port);

	platform_set_drvdata(pdev, dln2);

	/* initialize the i2c interface */
	ret = dln2_i2c_enable(dln2, true);
	if (ret < 0) {
	dev_err(dev, "failed to initialize adapter: %d\n", ret);
	return ret;
	}

	/* and finally attach to i2c layer */
	ret = i2c_add_adapter(&dln2->adapter);
	if (ret < 0) {
	dev_err(dev, "failed to add I2C adapter: %d\n", ret);
	goto out_disable;
	}

	return 0;

	out_disable:
	dln2_i2c_enable(dln2, false);

	return ret;
	}

	static int dln2_i2c_remove(struct platform_device *pdev)
	{
	struct dln2_i2c *dln2 = platform_get_drvdata(pdev);

	i2c_del_adapter(&dln2->adapter);
	dln2_i2c_enable(dln2, false);

	return 0;
	}

	static struct platform_driver dln2_i2c_driver = {
	.driver.name = "dln2-i2c",
	.probe = dln2_i2c_probe,
	.remove = dln2_i2c_remove,
	};

	module_platform_driver(dln2_i2c_driver);

	MODULE_AUTHOR("Laurentiu Palcu <laurentiu.palcu@intel.com>");
	MODULE_DESCRIPTION("Driver for the Diolan DLN2 I2C master interface");
	MODULE_LICENSE("GPL v2");
	MODULE_ALIAS("platform:dln2-i2c");