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|
/*
* 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, 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;
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_le
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