[deliverable/linux.git] / drivers / i2c / busses / i2c-viperboard.c

/*
 *  Nano River Technologies viperboard i2c master driver
 *
 *  (C) 2012 by Lemonage GmbH
 *  Author: Lars Poeschel <poeschel@lemonage.de>
 *  All rights reserved.
 *
 *  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;  either version 2 of the	License, or (at your
 *  option) any later version.
 *
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>

#include <linux/usb.h>
#include <linux/i2c.h>

#include <linux/mfd/viperboard.h>

struct vprbrd_i2c {
	struct i2c_adapter i2c;
	u8 bus_freq_param;
};

/* i2c bus frequency module parameter */
static u8 i2c_bus_param;
static unsigned int i2c_bus_freq = 100;
module_param(i2c_bus_freq, int, 0);
MODULE_PARM_DESC(i2c_bus_freq,
	"i2c bus frequency in khz (default is 100) valid values: 10, 100, 200, 400, 1000, 3000, 6000");

static int vprbrd_i2c_status(struct i2c_adapter *i2c,
	struct vprbrd_i2c_status *status, bool prev_error)
{
	u16 bytes_xfer;
	int ret;
	struct vprbrd *vb = (struct vprbrd *)i2c->algo_data;

	/* check for protocol error */
	bytes_xfer = sizeof(struct vprbrd_i2c_status);

	ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
		VPRBRD_USB_REQUEST_I2C, VPRBRD_USB_TYPE_IN, 0x0000, 0x0000,
		status, bytes_xfer, VPRBRD_USB_TIMEOUT_MS);

	if (ret != bytes_xfer)
		prev_error = true;

	if (prev_error) {
		dev_err(&i2c->dev, "failure in usb communication\n");
		return -EREMOTEIO;
	}

	dev_dbg(&i2c->dev, "  status = %d\n", status->status);
	if (status->status != 0x00) {
		dev_err(&i2c->dev, "failure: i2c protocol error\n");
		return -EPROTO;
	}
	return 0;
}

static int vprbrd_i2c_receive(struct usb_device *usb_dev,
	struct vprbrd_i2c_read_msg *rmsg, int bytes_xfer)
{
	int ret, bytes_actual;
	int error = 0;

	/* send the read request */
	ret = usb_bulk_msg(usb_dev,
		usb_sndbulkpipe(usb_dev, VPRBRD_EP_OUT), rmsg,
		sizeof(struct vprbrd_i2c_read_hdr), &bytes_actual,
		VPRBRD_USB_TIMEOUT_MS);

	if ((ret < 0)
		|| (bytes_actual != sizeof(struct vprbrd_i2c_read_hdr))) {
		dev_err(&usb_dev->dev, "failure transmitting usb\n");
		error = -EREMOTEIO;
	}

	/* read the actual data */
	ret = usb_bulk_msg(usb_dev,
		usb_rcvbulkpipe(usb_dev, VPRBRD_EP_IN), rmsg,
		bytes_xfer, &bytes_actual, VPRBRD_USB_TIMEOUT_MS);

	if ((ret < 0) || (bytes_xfer != bytes_actual)) {
		dev_err(&usb_dev->dev, "failure receiving usb\n");
		error = -EREMOTEIO;
	}
	return error;
}

static int vprbrd_i2c_addr(struct usb_device *usb_dev,
	struct vprbrd_i2c_addr_msg *amsg)
{
	int ret, bytes_actual;

	ret = usb_bulk_msg(usb_dev,
		usb_sndbulkpipe(usb_dev, VPRBRD_EP_OUT), amsg,
		sizeof(struct vprbrd_i2c_addr_msg), &bytes_actual,
		VPRBRD_USB_TIMEOUT_MS);

	if ((ret < 0) ||
			(sizeof(struct vprbrd_i2c_addr_msg) != bytes_actual)) {
		dev_err(&usb_dev->dev, "failure transmitting usb\n");
		return -EREMOTEIO;
	}
	return 0;
}

static int vprbrd_i2c_read(struct vprbrd *vb, struct i2c_msg *msg)
{
	int ret;
	u16 remain_len, bytes_xfer, len1, len2,
		start = 0x0000;
	struct vprbrd_i2c_read_msg *rmsg =
		(struct vprbrd_i2c_read_msg *)vb->buf;

	remain_len = msg->len;
	rmsg->header.cmd = VPRBRD_I2C_CMD_READ;
	while (remain_len > 0) {
		rmsg->header.addr = cpu_to_le16(start + 0x4000);
		if (remain_len <= 255) {
			len1 = remain_len;
			len2 = 0x00;
			rmsg->header.len0 = remain_len;
			rmsg->header.len1 = 0x00;
			rmsg->header.len2 = 0x00;
			rmsg->header.len3 = 0x00;
			rmsg->header.len4 = 0x00;
			rmsg->header.len5 = 0x00;
			remain_len = 0;
		} else if (remain_len <= 510) {
			len1 = remain_len;
			len2 = 0x00;
			rmsg->header.len0 = remain_len - 255;
			rmsg->header.len1 = 0xff;
			rmsg->header.len2 = 0x00;
			rmsg->header.len3 = 0x00;
			rmsg->header.len4 = 0x00;
			rmsg->header.len5 = 0x00;
			remain_len = 0;
		} else if (remain_len <= 512) {
			len1 = remain_len;
			len2 = 0x00;
			rmsg->header.len0 = remain_len - 510;
			rmsg->header.len1 = 0xff;
			rmsg->header.len2 = 0xff;
			rmsg->header.len3 = 0x00;
			rmsg->header.len4 = 0x00;
			rmsg->header.len5 = 0x00;
			remain_len = 0;
		} else if (remain_len <= 767) {
			len1 = 512;
			len2 = remain_len - 512;
			rmsg->header.len0 = 0x02;
			rmsg->header.len1 = 0xff;
			rmsg->header.len2 = 0xff;
			rmsg->header.len3 = remain_len - 512;
			rmsg->header.len4 = 0x00;
			rmsg->header.len5 = 0x00;
			bytes_xfer = remain_len;
			remain_len = 0;
		} else if (remain_len <= 1022) {
			len1 = 512;
			len2 = remain_len - 512;
			rmsg->header.len0 = 0x02;
			rmsg->header.len1 = 0xff;
			rmsg->header.len2 = 0xff;
			rmsg->header.len3 = remain_len - 767;
			rmsg->header.len4 = 0xff;
			rmsg->header.len5 = 0x00;
			remain_len = 0;
		} else if (remain_len <= 1024) {
			len1 = 512;
			len2 = remain_len - 512;
			rmsg->header.len0 = 0x02;
			rmsg->header.len1 = 0xff;
			rmsg->header.len2 = 0xff;
			rmsg->header.len3 = remain_len - 1022;
			rmsg->header.len4 = 0xff;
			rmsg->header.len5 = 0xff;
			remain_len = 0;
		} else {
			len1 = 512;
			len2 = 512;
			rmsg->header.len0 = 0x02;
			rmsg->header.len1 = 0xff;
			rmsg->header.len2 = 0xff;
			rmsg->header.len3 = 0x02;
			rmsg->header.len4 = 0xff;
			rmsg->header.len5 = 0xff;
			remain_len -= 1024;
			start += 1024;
		}
		rmsg->header.tf1 = cpu_to_le16(len1);
		rmsg->header.tf2 = cpu_to_le16(len2);

		/* first read transfer */
		ret = vprbrd_i2c_receive(vb->usb_dev, rmsg, len1);
		if (ret < 0)
			return ret;
		/* copy the received data */
		memcpy(msg->buf + start, rmsg, len1);

		/* second read transfer if neccessary */
		if (len2 > 0) {
			ret = vprbrd_i2c_receive(vb->usb_dev, rmsg, len2);
			if (ret < 0)
				return ret;
			/* copy the received data */
			memcpy(msg->buf + start + 512, rmsg, len2);
		}
	}
	return 0;
}

static int vprbrd_i2c_write(struct vprbrd *vb, struct i2c_msg *msg)
{
	int ret, bytes_actual;
	u16 remain_len, bytes_xfer,
		start = 0x0000;
	struct vprbrd_i2c_write_msg *wmsg =
		(struct vprbrd_i2c_write_msg *)vb->buf;

	remain_len = msg->len;
	wmsg->header.cmd = VPRBRD_I2C_CMD_WRITE;
	wmsg->header.last = 0x00;
	wmsg->header.chan = 0x00;
	wmsg->header.spi = 0x0000;
	while (remain_len > 0) {
		wmsg->header.addr = cpu_to_le16(start + 0x4000);
		if (remain_len > 503) {
			wmsg->header.len1 = 0xff;
			wmsg->header.len2 = 0xf8;
			remain_len -= 503;
			bytes_xfer = 503 + sizeof(struct vprbrd_i2c_write_hdr);
			start += 503;
		} else if (remain_len > 255) {
			wmsg->header.len1 = 0xff;
			wmsg->header.len2 = (remain_len - 255);
			bytes_xfer = remain_len +
				sizeof(struct vprbrd_i2c_write_hdr);
			remain_len = 0;
		} else {
			wmsg->header.len1 = remain_len;
			wmsg->header.len2 = 0x00;
			bytes_xfer = remain_len +
				sizeof(struct vprbrd_i2c_write_hdr);
			remain_len = 0;
		}
		memcpy(wmsg->data, msg->buf + start,
			bytes_xfer - sizeof(struct vprbrd_i2c_write_hdr));

		ret = usb_bulk_msg(vb->usb_dev,
			usb_sndbulkpipe(vb->usb_dev,
			VPRBRD_EP_OUT), wmsg,
			bytes_xfer, &bytes_actual, VPRBRD_USB_TIMEOUT_MS);
		if ((ret < 0) || (bytes_xfer != bytes_actual))
			return -EREMOTEIO;
	}
	return 0;
}

static int vprbrd_i2c_xfer(struct i2c_adapter *i2c, struct i2c_msg *msgs,
		int num)
{
	struct i2c_msg *pmsg;
	int i, ret,
		error = 0;
	struct vprbrd *vb = (struct vprbrd *)i2c->algo_data;
	struct vprbrd_i2c_addr_msg *amsg =
		(struct vprbrd_i2c_addr_msg *)vb->buf;
	struct vprbrd_i2c_status *smsg = (struct vprbrd_i2c_status *)vb->buf;

	dev_dbg(&i2c->dev, "master xfer %d messages:\n", num);

	for (i = 0 ; i < num ; i++) {
		pmsg = &msgs[i];

		dev_dbg(&i2c->dev,
			"  %d: %s (flags %d) %d bytes to 0x%02x\n",
			i, pmsg->flags & I2C_M_RD ? "read" : "write",
			pmsg->flags, pmsg->len, pmsg->addr);

		/* msgs longer than 2048 bytes are not supported by adapter */
		if (pmsg->len > 2048)
			return -EINVAL;

		mutex_lock(&vb->lock);
		/* directly send the message */
		if (pmsg->flags & I2C_M_RD) {
			/* read data */
			amsg->cmd = VPRBRD_I2C_CMD_ADDR;
			amsg->unknown2 = 0x00;
			amsg->unknown3 = 0x00;
			amsg->addr = pmsg->addr;
			amsg->unknown1 = 0x01;
			amsg->len = cpu_to_le16(pmsg->len);
			/* send the addr and len, we're interested to board */
			ret = vprbrd_i2c_addr(vb->usb_dev, amsg);
			if (ret < 0)
				error = ret;

			ret = vprbrd_i2c_read(vb, pmsg);
			if (ret < 0)
				error = ret;

			ret = vprbrd_i2c_status(i2c, smsg, error);
			if (ret < 0)
				error = ret;
			/* in case of protocol error, return the error */
			if (error < 0)
				goto error;
		} else {
			/* write data */
			ret = vprbrd_i2c_write(vb, pmsg);

			amsg->cmd = VPRBRD_I2C_CMD_ADDR;
			amsg->unknown2 = 0x00;
			amsg->unknown3 = 0x00;
			amsg->addr = pmsg->addr;
			amsg->unknown1 = 0x00;
			amsg->len = cpu_to_le16(pmsg->len);
			/* send the addr, the data goes to to board */
			ret = vprbrd_i2c_addr(vb->usb_dev, amsg);
			if (ret < 0)
				error = ret;

			ret = vprbrd_i2c_status(i2c, smsg, error);
			if (ret < 0)
				error = ret;

			if (error < 0)
				goto error;
		}
		mutex_unlock(&vb->lock);
	}
	return 0;
error:
	mutex_unlock(&vb->lock);
	return error;
}

static u32 vprbrd_i2c_func(struct i2c_adapter *i2c)
{
	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}

/* This is the actual algorithm we define */
static const struct i2c_algorithm vprbrd_algorithm = {
	.master_xfer	= vprbrd_i2c_xfer,
	.functionality	= vprbrd_i2c_func,
};

static int vprbrd_i2c_probe(struct platform_device *pdev)
{
	struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
	struct vprbrd_i2c *vb_i2c;
	int ret;
	int pipe;

	vb_i2c = kzalloc(sizeof(*vb_i2c), GFP_KERNEL);
	if (vb_i2c == NULL)
		return -ENOMEM;

	/* setup i2c adapter description */
	vb_i2c->i2c.owner = THIS_MODULE;
	vb_i2c->i2c.class = I2C_CLASS_HWMON;
	vb_i2c->i2c.algo = &vprbrd_algorithm;
	vb_i2c->i2c.algo_data = vb;
	/* save the param in usb capabable memory */
	vb_i2c->bus_freq_param = i2c_bus_param;

	snprintf(vb_i2c->i2c.name, sizeof(vb_i2c->i2c.name),
		 "viperboard at bus %03d device %03d",
		 vb->usb_dev->bus->busnum, vb->usb_dev->devnum);

	/* setting the bus frequency */
	if ((i2c_bus_param <= VPRBRD_I2C_FREQ_10KHZ)
		&& (i2c_bus_param >= VPRBRD_I2C_FREQ_6MHZ)) {
		pipe = usb_sndctrlpipe(vb->usb_dev, 0);
		ret = usb_control_msg(vb->usb_dev, pipe,
			VPRBRD_USB_REQUEST_I2C_FREQ, VPRBRD_USB_TYPE_OUT,
			0x0000, 0x0000, &vb_i2c->bus_freq_param, 1,
			VPRBRD_USB_TIMEOUT_MS);
	    if (ret != 1) {
		dev_err(&pdev->dev,
			"failure setting i2c_bus_freq to %d\n", i2c_bus_freq);
		ret = -EIO;
		goto error;
	    }
	} else {
		dev_err(&pdev->dev,
			"invalid i2c_bus_freq setting:%d\n", i2c_bus_freq);
		ret = -EIO;
		goto error;
	}

	vb_i2c->i2c.dev.parent = &pdev->dev;

	/* attach to i2c layer */
	i2c_add_adapter(&vb_i2c->i2c);

	platform_set_drvdata(pdev, vb_i2c);

	return 0;

error:
	kfree(vb_i2c);
	return ret;
}

static int vprbrd_i2c_remove(struct platform_device *pdev)
{
	struct vprbrd_i2c *vb_i2c = platform_get_drvdata(pdev);

	i2c_del_adapter(&vb_i2c->i2c);

	return 0;
}

static struct platform_driver vprbrd_i2c_driver = {
	.driver.name	= "viperboard-i2c",
	.driver.owner	= THIS_MODULE,
	.probe		= vprbrd_i2c_probe,
	.remove		= vprbrd_i2c_remove,
};

static int __init vprbrd_i2c_init(void)
{
	switch (i2c_bus_freq) {
	case 6000:
		i2c_bus_param = VPRBRD_I2C_FREQ_6MHZ;
		break;
	case 3000:
		i2c_bus_param = VPRBRD_I2C_FREQ_3MHZ;
		break;
	case 1000:
		i2c_bus_param = VPRBRD_I2C_FREQ_1MHZ;
		break;
	case 400:
		i2c_bus_param = VPRBRD_I2C_FREQ_400KHZ;
		break;
	case 200:
		i2c_bus_param = VPRBRD_I2C_FREQ_200KHZ;
		break;
	case 100:
		i2c_bus_param = VPRBRD_I2C_FREQ_100KHZ;
		break;
	case 10:
		i2c_bus_param = VPRBRD_I2C_FREQ_10KHZ;
		break;
	default:
		pr_warn("invalid i2c_bus_freq (%d)\n", i2c_bus_freq);
		i2c_bus_param = VPRBRD_I2C_FREQ_100KHZ;
	}

	return platform_driver_register(&vprbrd_i2c_driver);
}
subsys_initcall(vprbrd_i2c_init);

static void __exit vprbrd_i2c_exit(void)
{
	platform_driver_unregister(&vprbrd_i2c_driver);
}
module_exit(vprbrd_i2c_exit);

MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
MODULE_DESCRIPTION("I2C master driver for Nano River Techs Viperboard");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:viperboard-i2c");
Commit	Line	Data
174a13aa LP	1	/*
	2	* Nano River Technologies viperboard i2c master driver
	3	*
	4	* (C) 2012 by Lemonage GmbH
	5	* Author: Lars Poeschel <poeschel@lemonage.de>
	6	* All rights reserved.
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public License as published by the
	10	* Free Software Foundation; either version 2 of the License, or (at your
	11	* option) any later version.
	12	*
	13	*/
	14
	15	#include <linux/kernel.h>
	16	#include <linux/errno.h>
	17	#include <linux/module.h>
	18	#include <linux/slab.h>
	19	#include <linux/types.h>
	20	#include <linux/mutex.h>
	21	#include <linux/platform_device.h>
	22
	23	#include <linux/usb.h>
	24	#include <linux/i2c.h>
	25
	26	#include <linux/mfd/viperboard.h>
	27
	28	struct vprbrd_i2c {
	29	struct i2c_adapter i2c;
	30	u8 bus_freq_param;
	31	};
	32
	33	/* i2c bus frequency module parameter */
	34	static u8 i2c_bus_param;
	35	static unsigned int i2c_bus_freq = 100;
	36	module_param(i2c_bus_freq, int, 0);
	37	MODULE_PARM_DESC(i2c_bus_freq,
	38	"i2c bus frequency in khz (default is 100) valid values: 10, 100, 200, 400, 1000, 3000, 6000");
	39
	40	static int vprbrd_i2c_status(struct i2c_adapter *i2c,
	41	struct vprbrd_i2c_status *status, bool prev_error)
	42	{
	43	u16 bytes_xfer;
	44	int ret;
	45	struct vprbrd vb = (struct vprbrd )i2c->algo_data;
	46
	47	/* check for protocol error */
	48	bytes_xfer = sizeof(struct vprbrd_i2c_status);
	49
	50	ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
	51	VPRBRD_USB_REQUEST_I2C, VPRBRD_USB_TYPE_IN, 0x0000, 0x0000,
	52	status, bytes_xfer, VPRBRD_USB_TIMEOUT_MS);
	53
	54	if (ret != bytes_xfer)
	55	prev_error = true;
	56
	57	if (prev_error) {
	58	dev_err(&i2c->dev, "failure in usb communication\n");
	59	return -EREMOTEIO;
	60	}
	61
	62	dev_dbg(&i2c->dev, " status = %d\n", status->status);
	63	if (status->status != 0x00) {
	64	dev_err(&i2c->dev, "failure: i2c protocol error\n");
65	return -EPROTO;
66	}
67	return 0;
68	}
69
70	static int vprbrd_i2c_receive(struct usb_device *usb_dev,
71	struct vprbrd_i2c_read_msg *rmsg, int bytes_xfer)
72	{
73	int ret, bytes_actual;
74	int error = 0;
75
76	/* send the read request */
77	ret = usb_bulk_msg(usb_dev,
78	usb_sndbulkpipe(usb_dev, VPRBRD_EP_OUT), rmsg,
79	sizeof(struct vprbrd_i2c_read_hdr), &bytes_actual,
80	VPRBRD_USB_TIMEOUT_MS);
81
82	if ((ret < 0)
83	\|\| (bytes_actual != sizeof(struct vprbrd_i2c_read_hdr))) {
84	dev_err(&usb_dev->dev, "failure transmitting usb\n");
85	error = -EREMOTEIO;
86	}
87
88	/* read the actual data */
89	ret = usb_bulk_msg(usb_dev,
90	usb_rcvbulkpipe(usb_dev, VPRBRD_EP_IN), rmsg,
91	bytes_xfer, &bytes_actual, VPRBRD_USB_TIMEOUT_MS);
92
93	if ((ret < 0) \|\| (bytes_xfer != bytes_actual)) {
94	dev_err(&usb_dev->dev, "failure receiving usb\n");
95	error = -EREMOTEIO;
96	}
97	return error;
98	}
99
100	static int vprbrd_i2c_addr(struct usb_device *usb_dev,
101	struct vprbrd_i2c_addr_msg *amsg)
102	{
103	int ret, bytes_actual;
104
105	ret = usb_bulk_msg(usb_dev,
106	usb_sndbulkpipe(usb_dev, VPRBRD_EP_OUT), amsg,
107	sizeof(struct vprbrd_i2c_addr_msg), &bytes_actual,
108	VPRBRD_USB_TIMEOUT_MS);
109
110	if ((ret < 0) \|\|
111	(sizeof(struct vprbrd_i2c_addr_msg) != bytes_actual)) {
112	dev_err(&usb_dev->dev, "failure transmitting usb\n");
113	return -EREMOTEIO;
114	}
115	return 0;
116	}
117
118	static int vprbrd_i2c_read(struct vprbrd vb, struct i2c_msg msg)
119	{
120	int ret;
121	u16 remain_len, bytes_xfer, len1, len2,
122	start = 0x0000;
123	struct vprbrd_i2c_read_msg *rmsg =
124	(struct vprbrd_i2c_read_msg *)vb->buf;
125
126	remain_len = msg->len;
127	rmsg->header.cmd = VPRBRD_I2C_CMD_READ;
128	while (remain_len > 0) {
129	rmsg->header.addr = cpu_to_le16(start + 0x4000);
130	if (remain_len <= 255) {
131	len1 = remain_len;
132	len2 = 0x00;
133	rmsg->header.len0 = remain_len;
134	rmsg->header.len1 = 0x00;
135	rmsg->header.len2 = 0x00;
136	rmsg->header.len3 = 0x00;
137	rmsg->header.len4 = 0x00;
138	rmsg->header.len5 = 0x00;
139	remain_len = 0;
140	} else if (remain_len <= 510) {
141	len1 = remain_len;
142	len2 = 0x00;
143	rmsg->header.len0 = remain_len - 255;
144	rmsg->header.len1 = 0xff;
145	rmsg->header.len2 = 0x00;
146	rmsg->header.len3 = 0x00;
147	rmsg->header.len4 = 0x00;
148	rmsg->header.len5 = 0x00;
149	remain_len = 0;
150	} else if (remain_len <= 512) {
151	len1 = remain_len;
152	len2 = 0x00;
153	rmsg->header.len0 = remain_len - 510;
154	rmsg->header.len1 = 0xff;
155	rmsg->header.len2 = 0xff;
156	rmsg->header.len3 = 0x00;
157	rmsg->header.len4 = 0x00;
158	rmsg->header.len5 = 0x00;
159	remain_len = 0;
160	} else if (remain_len <= 767) {
161	len1 = 512;
162	len2 = remain_len - 512;
163	rmsg->header.len0 = 0x02;
164	rmsg->header.len1 = 0xff;
165	rmsg->header.len2 = 0xff;
166	rmsg->header.len3 = remain_len - 512;
167	rmsg->header.len4 = 0x00;
168	rmsg->header.len5 = 0x00;
169	bytes_xfer = remain_len;
170	remain_len = 0;
171	} else if (remain_len <= 1022) {
172	len1 = 512;
173	len2 = remain_len - 512;
174	rmsg->header.len0 = 0x02;
175	rmsg->header.len1 = 0xff;
176	rmsg->header.len2 = 0xff;
177	rmsg->header.len3 = remain_len - 767;
178	rmsg->header.len4 = 0xff;
179	rmsg->header.len5 = 0x00;
180	remain_len = 0;
181	} else if (remain_len <= 1024) {
182	len1 = 512;
183	len2 = remain_len - 512;
184	rmsg->header.len0 = 0x02;
185	rmsg->header.len1 = 0xff;
186	rmsg->header.len2 = 0xff;
187	rmsg->header.len3 = remain_len - 1022;
188	rmsg->header.len4 = 0xff;
189	rmsg->header.len5 = 0xff;
190	remain_len = 0;
191	} else {
192	len1 = 512;
193	len2 = 512;
194	rmsg->header.len0 = 0x02;
195	rmsg->header.len1 = 0xff;
196	rmsg->header.len2 = 0xff;
197	rmsg->header.len3 = 0x02;
198	rmsg->header.len4 = 0xff;
199	rmsg->header.len5 = 0xff;
200	remain_len -= 1024;
201	start += 1024;
202	}
203	rmsg->header.tf1 = cpu_to_le16(len1);
204	rmsg->header.tf2 = cpu_to_le16(len2);
205
206	/* first read transfer */
207	ret = vprbrd_i2c_receive(vb->usb_dev, rmsg, len1);
208	if (ret < 0)
209	return ret;
210	/* copy the received data */
211	memcpy(msg->buf + start, rmsg, len1);
212
213	/* second read transfer if neccessary */
214	if (len2 > 0) {
215	ret = vprbrd_i2c_receive(vb->usb_dev, rmsg, len2);
216	if (ret < 0)
217	return ret;
218	/* copy the received data */
219	memcpy(msg->buf + start + 512, rmsg, len2);
220	}
221	}
222	return 0;
223	}
224
225	static int vprbrd_i2c_write(struct vprbrd vb, struct i2c_msg msg)
226	{
227	int ret, bytes_actual;
228	u16 remain_len, bytes_xfer,
229	start = 0x0000;
230	struct vprbrd_i2c_write_msg *wmsg =
231	(struct vprbrd_i2c_write_msg *)vb->buf;
232
233	remain_len = msg->len;
234	wmsg->header.cmd = VPRBRD_I2C_CMD_WRITE;
235	wmsg->header.last = 0x00;
236	wmsg->header.chan = 0x00;
237	wmsg->header.spi = 0x0000;
238	while (remain_len > 0) {
239	wmsg->header.addr = cpu_to_le16(start + 0x4000);
240	if (remain_len > 503) {
241	wmsg->header.len1 = 0xff;
242	wmsg->header.len2 = 0xf8;
243	remain_len -= 503;
244	bytes_xfer = 503 + sizeof(struct vprbrd_i2c_write_hdr);
245	start += 503;
246	} else if (remain_len > 255) {
247	wmsg->header.len1 = 0xff;
248	wmsg->header.len2 = (remain_len - 255);
249	bytes_xfer = remain_len +
250	sizeof(struct vprbrd_i2c_write_hdr);
251	remain_len = 0;
252	} else {
253	wmsg->header.len1 = remain_len;
254	wmsg->header.len2 = 0x00;
255	bytes_xfer = remain_len +
256	sizeof(struct vprbrd_i2c_write_hdr);
257	remain_len = 0;
258	}
259	memcpy(wmsg->data, msg->buf + start,
260	bytes_xfer - sizeof(struct vprbrd_i2c_write_hdr));
261
262	ret = usb_bulk_msg(vb->usb_dev,
263	usb_sndbulkpipe(vb->usb_dev,
264	VPRBRD_EP_OUT), wmsg,
265	bytes_xfer, &bytes_actual, VPRBRD_USB_TIMEOUT_MS);
266	if ((ret < 0) \|\| (bytes_xfer != bytes_actual))
267	return -EREMOTEIO;
268	}
269	return 0;
270	}
271
272	static int vprbrd_i2c_xfer(struct i2c_adapter i2c, struct i2c_msg msgs,
273	int num)
274	{
275	struct i2c_msg *pmsg;
276	int i, ret,
277	error = 0;
278	struct vprbrd vb = (struct vprbrd )i2c->algo_data;
279	struct vprbrd_i2c_addr_msg *amsg =
280	(struct vprbrd_i2c_addr_msg *)vb->buf;
281	struct vprbrd_i2c_status smsg = (struct vprbrd_i2c_status )vb->buf;
282
283	dev_dbg(&i2c->dev, "master xfer %d messages:\n", num);
284
285	for (i = 0 ; i < num ; i++) {
286	pmsg = &msgs[i];
287
288	dev_dbg(&i2c->dev,
289	" %d: %s (flags %d) %d bytes to 0x%02x\n",
290	i, pmsg->flags & I2C_M_RD ? "read" : "write",
291	pmsg->flags, pmsg->len, pmsg->addr);
292
293	/* msgs longer than 2048 bytes are not supported by adapter */
294	if (pmsg->len > 2048)
295	return -EINVAL;
296
297	mutex_lock(&vb->lock);
298	/* directly send the message */
299	if (pmsg->flags & I2C_M_RD) {
300	/* read data */
301	amsg->cmd = VPRBRD_I2C_CMD_ADDR;
302	amsg->unknown2 = 0x00;
303	amsg->unknown3 = 0x00;
304	amsg->addr = pmsg->addr;
305	amsg->unknown1 = 0x01;
306	amsg->len = cpu_to_le16(pmsg->len);
307	/* send the addr and len, we're interested to board */
308	ret = vprbrd_i2c_addr(vb->usb_dev, amsg);
309	if (ret < 0)
310	error = ret;
311
312	ret = vprbrd_i2c_read(vb, pmsg);
313	if (ret < 0)
314	error = ret;
315
316	ret = vprbrd_i2c_status(i2c, smsg, error);
317	if (ret < 0)
318	error = ret;
319	/* in case of protocol error, return the error */
320	if (error < 0)
321	goto error;
322	} else {
323	/* write data */
324	ret = vprbrd_i2c_write(vb, pmsg);
325
326	amsg->cmd = VPRBRD_I2C_CMD_ADDR;
327	amsg->unknown2 = 0x00;
328	amsg->unknown3 = 0x00;
329	amsg->addr = pmsg->addr;
330	amsg->unknown1 = 0x00;
331	amsg->len = cpu_to_le16(pmsg->len);
332	/* send the addr, the data goes to to board */
333	ret = vprbrd_i2c_addr(vb->usb_dev, amsg);
334	if (ret < 0)
335	error = ret;
336
337	ret = vprbrd_i2c_status(i2c, smsg, error);
338	if (ret < 0)
339	error = ret;
340
341	if (error < 0)
342	goto error;
343	}
344	mutex_unlock(&vb->lock);
345	}
346	return 0;
347	error:
348	mutex_unlock(&vb->lock);
349	return error;
350	}
351
352	static u32 vprbrd_i2c_func(struct i2c_adapter *i2c)
353	{
354	return I2C_FUNC_I2C \| I2C_FUNC_SMBUS_EMUL;
355	}
356
357	/* This is the actual algorithm we define */
358	static const struct i2c_algorithm vprbrd_algorithm = {
359	.master_xfer = vprbrd_i2c_xfer,
360	.functionality = vprbrd_i2c_func,
361	};
362
0b255e92	363	static int vprbrd_i2c_probe(struct platform_device *pdev)
174a13aa LP	364	{
	365	struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
	366	struct vprbrd_i2c *vb_i2c;
	367	int ret;
	368	int pipe;
	369
	370	vb_i2c = kzalloc(sizeof(*vb_i2c), GFP_KERNEL);
	371	if (vb_i2c == NULL)
	372	return -ENOMEM;
	373
	374	/* setup i2c adapter description */
	375	vb_i2c->i2c.owner = THIS_MODULE;
	376	vb_i2c->i2c.class = I2C_CLASS_HWMON;
	377	vb_i2c->i2c.algo = &vprbrd_algorithm;
	378	vb_i2c->i2c.algo_data = vb;
	379	/* save the param in usb capabable memory */
	380	vb_i2c->bus_freq_param = i2c_bus_param;
	381
	382	snprintf(vb_i2c->i2c.name, sizeof(vb_i2c->i2c.name),
	383	"viperboard at bus %03d device %03d",
	384	vb->usb_dev->bus->busnum, vb->usb_dev->devnum);
	385
	386	/* setting the bus frequency */
	387	if ((i2c_bus_param <= VPRBRD_I2C_FREQ_10KHZ)
	388	&& (i2c_bus_param >= VPRBRD_I2C_FREQ_6MHZ)) {
	389	pipe = usb_sndctrlpipe(vb->usb_dev, 0);
	390	ret = usb_control_msg(vb->usb_dev, pipe,
	391	VPRBRD_USB_REQUEST_I2C_FREQ, VPRBRD_USB_TYPE_OUT,
	392	0x0000, 0x0000, &vb_i2c->bus_freq_param, 1,
	393	VPRBRD_USB_TIMEOUT_MS);
	394	if (ret != 1) {
	395	dev_err(&pdev->dev,
	396	"failure setting i2c_bus_freq to %d\n", i2c_bus_freq);
	397	ret = -EIO;
	398	goto error;
	399	}
	400	} else {
	401	dev_err(&pdev->dev,
	402	"invalid i2c_bus_freq setting:%d\n", i2c_bus_freq);
	403	ret = -EIO;
	404	goto error;
	405	}
	406
	407	vb_i2c->i2c.dev.parent = &pdev->dev;
	408
	409	/* attach to i2c layer */
	410	i2c_add_adapter(&vb_i2c->i2c);
	411
	412	platform_set_drvdata(pdev, vb_i2c);
	413
	414	return 0;
	415
	416	error:
	417	kfree(vb_i2c);
	418	return ret;
	419	}
	420
0b255e92	421	static int vprbrd_i2c_remove(struct platform_device *pdev)
174a13aa LP	422	{
174a13aa LP	423	struct vprbrd_i2c *vb_i2c = platform_get_drvdata(pdev);
174a13aa	424
bf51a8c5	425	i2c_del_adapter(&vb_i2c->i2c);
174a13aa	426
bf51a8c5	427	return 0;
174a13aa LP	428	}
	429
	430	static struct platform_driver vprbrd_i2c_driver = {
	431	.driver.name = "viperboard-i2c",
	432	.driver.owner = THIS_MODULE,
	433	.probe = vprbrd_i2c_probe,
0b255e92	434	.remove = vprbrd_i2c_remove,
174a13aa LP	435	};
	436
	437	static int __init vprbrd_i2c_init(void)
	438	{
	439	switch (i2c_bus_freq) {
	440	case 6000:
	441	i2c_bus_param = VPRBRD_I2C_FREQ_6MHZ;
	442	break;
	443	case 3000:
	444	i2c_bus_param = VPRBRD_I2C_FREQ_3MHZ;
	445	break;
	446	case 1000:
	447	i2c_bus_param = VPRBRD_I2C_FREQ_1MHZ;
	448	break;
	449	case 400:
	450	i2c_bus_param = VPRBRD_I2C_FREQ_400KHZ;
	451	break;
	452	case 200:
	453	i2c_bus_param = VPRBRD_I2C_FREQ_200KHZ;
	454	break;
	455	case 100:
	456	i2c_bus_param = VPRBRD_I2C_FREQ_100KHZ;
	457	break;
	458	case 10:
	459	i2c_bus_param = VPRBRD_I2C_FREQ_10KHZ;
	460	break;
	461	default:
	462	pr_warn("invalid i2c_bus_freq (%d)\n", i2c_bus_freq);
	463	i2c_bus_param = VPRBRD_I2C_FREQ_100KHZ;
	464	}
	465
	466	return platform_driver_register(&vprbrd_i2c_driver);
	467	}
	468	subsys_initcall(vprbrd_i2c_init);
	469
	470	static void __exit vprbrd_i2c_exit(void)
	471	{
	472	platform_driver_unregister(&vprbrd_i2c_driver);
	473	}
	474	module_exit(vprbrd_i2c_exit);
	475
	476	MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
	477	MODULE_DESCRIPTION("I2C master driver for Nano River Techs Viperboard");
	478	MODULE_LICENSE("GPL");
	479	MODULE_ALIAS("platform:viperboard-i2c");