536 lines
13 KiB
C
536 lines
13 KiB
C
/*
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* Driver for the Diolan u2c-12 USB-I2C adapter
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*
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* Copyright (c) 2010-2011 Ericsson AB
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*
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* Derived from:
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* i2c-tiny-usb.c
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* Copyright (C) 2006-2007 Till Harbaum (Till@Harbaum.org)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2.
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*/
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/usb.h>
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#include <linux/i2c.h>
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#define DRIVER_NAME "i2c-diolan-u2c"
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#define USB_VENDOR_ID_DIOLAN 0x0abf
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#define USB_DEVICE_ID_DIOLAN_U2C 0x3370
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#define DIOLAN_OUT_EP 0x02
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#define DIOLAN_IN_EP 0x84
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/* commands via USB, must match command ids in the firmware */
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#define CMD_I2C_READ 0x01
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#define CMD_I2C_WRITE 0x02
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#define CMD_I2C_SCAN 0x03 /* Returns list of detected devices */
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#define CMD_I2C_RELEASE_SDA 0x04
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#define CMD_I2C_RELEASE_SCL 0x05
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#define CMD_I2C_DROP_SDA 0x06
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#define CMD_I2C_DROP_SCL 0x07
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#define CMD_I2C_READ_SDA 0x08
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#define CMD_I2C_READ_SCL 0x09
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#define CMD_GET_FW_VERSION 0x0a
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#define CMD_GET_SERIAL 0x0b
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#define CMD_I2C_START 0x0c
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#define CMD_I2C_STOP 0x0d
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#define CMD_I2C_REPEATED_START 0x0e
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#define CMD_I2C_PUT_BYTE 0x0f
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#define CMD_I2C_GET_BYTE 0x10
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#define CMD_I2C_PUT_ACK 0x11
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#define CMD_I2C_GET_ACK 0x12
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#define CMD_I2C_PUT_BYTE_ACK 0x13
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#define CMD_I2C_GET_BYTE_ACK 0x14
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#define CMD_I2C_SET_SPEED 0x1b
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#define CMD_I2C_GET_SPEED 0x1c
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#define CMD_I2C_SET_CLK_SYNC 0x24
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#define CMD_I2C_GET_CLK_SYNC 0x25
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#define CMD_I2C_SET_CLK_SYNC_TO 0x26
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#define CMD_I2C_GET_CLK_SYNC_TO 0x27
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#define RESP_OK 0x00
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#define RESP_FAILED 0x01
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#define RESP_BAD_MEMADDR 0x04
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#define RESP_DATA_ERR 0x05
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#define RESP_NOT_IMPLEMENTED 0x06
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#define RESP_NACK 0x07
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#define RESP_TIMEOUT 0x09
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#define U2C_I2C_SPEED_FAST 0 /* 400 kHz */
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#define U2C_I2C_SPEED_STD 1 /* 100 kHz */
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#define U2C_I2C_SPEED_2KHZ 242 /* 2 kHz, minimum speed */
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#define U2C_I2C_SPEED(f) ((DIV_ROUND_UP(1000000, (f)) - 10) / 2 + 1)
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#define U2C_I2C_FREQ_FAST 400000
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#define U2C_I2C_FREQ_STD 100000
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#define U2C_I2C_FREQ(s) (1000000 / (2 * (s - 1) + 10))
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#define DIOLAN_USB_TIMEOUT 100 /* in ms */
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#define DIOLAN_SYNC_TIMEOUT 20 /* in ms */
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#define DIOLAN_OUTBUF_LEN 128
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#define DIOLAN_FLUSH_LEN (DIOLAN_OUTBUF_LEN - 4)
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#define DIOLAN_INBUF_LEN 256 /* Maximum supported receive length */
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/* Structure to hold all of our device specific stuff */
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struct i2c_diolan_u2c {
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u8 obuffer[DIOLAN_OUTBUF_LEN]; /* output buffer */
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u8 ibuffer[DIOLAN_INBUF_LEN]; /* input buffer */
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struct usb_device *usb_dev; /* the usb device for this device */
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struct usb_interface *interface;/* the interface for this device */
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struct i2c_adapter adapter; /* i2c related things */
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int olen; /* Output buffer length */
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int ocount; /* Number of enqueued messages */
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};
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static uint frequency = U2C_I2C_FREQ_STD; /* I2C clock frequency in Hz */
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module_param(frequency, uint, S_IRUGO | S_IWUSR);
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MODULE_PARM_DESC(frequency, "I2C clock frequency in hertz");
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/* usb layer */
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/* Send command to device, and get response. */
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static int diolan_usb_transfer(struct i2c_diolan_u2c *dev)
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{
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int ret = 0;
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int actual;
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int i;
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if (!dev->olen || !dev->ocount)
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return -EINVAL;
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ret = usb_bulk_msg(dev->usb_dev,
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usb_sndbulkpipe(dev->usb_dev, DIOLAN_OUT_EP),
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dev->obuffer, dev->olen, &actual,
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DIOLAN_USB_TIMEOUT);
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if (!ret) {
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for (i = 0; i < dev->ocount; i++) {
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int tmpret;
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tmpret = usb_bulk_msg(dev->usb_dev,
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usb_rcvbulkpipe(dev->usb_dev,
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DIOLAN_IN_EP),
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dev->ibuffer,
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sizeof(dev->ibuffer), &actual,
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DIOLAN_USB_TIMEOUT);
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/*
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* Stop command processing if a previous command
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* returned an error.
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* Note that we still need to retrieve all messages.
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*/
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if (ret < 0)
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continue;
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ret = tmpret;
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if (ret == 0 && actual > 0) {
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switch (dev->ibuffer[actual - 1]) {
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case RESP_NACK:
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/*
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* Return ENXIO if NACK was received as
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* response to the address phase,
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* EIO otherwise
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*/
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ret = i == 1 ? -ENXIO : -EIO;
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break;
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case RESP_TIMEOUT:
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ret = -ETIMEDOUT;
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break;
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case RESP_OK:
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/* strip off return code */
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ret = actual - 1;
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break;
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default:
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ret = -EIO;
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break;
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}
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}
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}
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}
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dev->olen = 0;
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dev->ocount = 0;
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return ret;
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}
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static int diolan_write_cmd(struct i2c_diolan_u2c *dev, bool flush)
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{
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if (flush || dev->olen >= DIOLAN_FLUSH_LEN)
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return diolan_usb_transfer(dev);
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return 0;
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}
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/* Send command (no data) */
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static int diolan_usb_cmd(struct i2c_diolan_u2c *dev, u8 command, bool flush)
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{
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dev->obuffer[dev->olen++] = command;
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dev->ocount++;
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return diolan_write_cmd(dev, flush);
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}
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/* Send command with one byte of data */
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static int diolan_usb_cmd_data(struct i2c_diolan_u2c *dev, u8 command, u8 data,
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bool flush)
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{
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dev->obuffer[dev->olen++] = command;
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dev->obuffer[dev->olen++] = data;
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dev->ocount++;
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return diolan_write_cmd(dev, flush);
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}
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/* Send command with two bytes of data */
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static int diolan_usb_cmd_data2(struct i2c_diolan_u2c *dev, u8 command, u8 d1,
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u8 d2, bool flush)
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{
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dev->obuffer[dev->olen++] = command;
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dev->obuffer[dev->olen++] = d1;
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dev->obuffer[dev->olen++] = d2;
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dev->ocount++;
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return diolan_write_cmd(dev, flush);
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}
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/*
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* Flush input queue.
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* If we don't do this at startup and the controller has queued up
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* messages which were not retrieved, it will stop responding
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* at some point.
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*/
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static void diolan_flush_input(struct i2c_diolan_u2c *dev)
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{
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int i;
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for (i = 0; i < 10; i++) {
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int actual = 0;
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int ret;
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ret = usb_bulk_msg(dev->usb_dev,
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usb_rcvbulkpipe(dev->usb_dev, DIOLAN_IN_EP),
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dev->ibuffer, sizeof(dev->ibuffer), &actual,
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DIOLAN_USB_TIMEOUT);
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if (ret < 0 || actual == 0)
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break;
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}
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if (i == 10)
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dev_err(&dev->interface->dev, "Failed to flush input buffer\n");
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}
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static int diolan_i2c_start(struct i2c_diolan_u2c *dev)
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{
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return diolan_usb_cmd(dev, CMD_I2C_START, false);
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}
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static int diolan_i2c_repeated_start(struct i2c_diolan_u2c *dev)
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{
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return diolan_usb_cmd(dev, CMD_I2C_REPEATED_START, false);
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}
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static int diolan_i2c_stop(struct i2c_diolan_u2c *dev)
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{
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return diolan_usb_cmd(dev, CMD_I2C_STOP, true);
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}
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static int diolan_i2c_get_byte_ack(struct i2c_diolan_u2c *dev, bool ack,
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u8 *byte)
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{
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int ret;
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ret = diolan_usb_cmd_data(dev, CMD_I2C_GET_BYTE_ACK, ack, true);
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if (ret > 0)
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*byte = dev->ibuffer[0];
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else if (ret == 0)
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ret = -EIO;
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return ret;
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}
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static int diolan_i2c_put_byte_ack(struct i2c_diolan_u2c *dev, u8 byte)
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{
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return diolan_usb_cmd_data(dev, CMD_I2C_PUT_BYTE_ACK, byte, false);
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}
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static int diolan_set_speed(struct i2c_diolan_u2c *dev, u8 speed)
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{
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return diolan_usb_cmd_data(dev, CMD_I2C_SET_SPEED, speed, true);
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}
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/* Enable or disable clock synchronization (stretching) */
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static int diolan_set_clock_synch(struct i2c_diolan_u2c *dev, bool enable)
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{
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return diolan_usb_cmd_data(dev, CMD_I2C_SET_CLK_SYNC, enable, true);
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}
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/* Set clock synchronization timeout in ms */
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static int diolan_set_clock_synch_timeout(struct i2c_diolan_u2c *dev, int ms)
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{
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int to_val = ms * 10;
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return diolan_usb_cmd_data2(dev, CMD_I2C_SET_CLK_SYNC_TO,
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to_val & 0xff, (to_val >> 8) & 0xff, true);
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}
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static void diolan_fw_version(struct i2c_diolan_u2c *dev)
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{
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int ret;
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ret = diolan_usb_cmd(dev, CMD_GET_FW_VERSION, true);
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if (ret >= 2)
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dev_info(&dev->interface->dev,
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"Diolan U2C firmware version %u.%u\n",
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(unsigned int)dev->ibuffer[0],
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(unsigned int)dev->ibuffer[1]);
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}
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static void diolan_get_serial(struct i2c_diolan_u2c *dev)
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{
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int ret;
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u32 serial;
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ret = diolan_usb_cmd(dev, CMD_GET_SERIAL, true);
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if (ret >= 4) {
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serial = le32_to_cpu(*(u32 *)dev->ibuffer);
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dev_info(&dev->interface->dev,
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"Diolan U2C serial number %u\n", serial);
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}
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}
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static int diolan_init(struct i2c_diolan_u2c *dev)
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{
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int speed, ret;
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if (frequency >= 200000) {
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speed = U2C_I2C_SPEED_FAST;
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frequency = U2C_I2C_FREQ_FAST;
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} else if (frequency >= 100000 || frequency == 0) {
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speed = U2C_I2C_SPEED_STD;
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frequency = U2C_I2C_FREQ_STD;
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} else {
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speed = U2C_I2C_SPEED(frequency);
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if (speed > U2C_I2C_SPEED_2KHZ)
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speed = U2C_I2C_SPEED_2KHZ;
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frequency = U2C_I2C_FREQ(speed);
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}
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dev_info(&dev->interface->dev,
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"Diolan U2C at USB bus %03d address %03d speed %d Hz\n",
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dev->usb_dev->bus->busnum, dev->usb_dev->devnum, frequency);
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diolan_flush_input(dev);
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diolan_fw_version(dev);
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diolan_get_serial(dev);
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/* Set I2C speed */
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ret = diolan_set_speed(dev, speed);
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if (ret < 0)
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return ret;
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/* Configure I2C clock synchronization */
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ret = diolan_set_clock_synch(dev, speed != U2C_I2C_SPEED_FAST);
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if (ret < 0)
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return ret;
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if (speed != U2C_I2C_SPEED_FAST)
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ret = diolan_set_clock_synch_timeout(dev, DIOLAN_SYNC_TIMEOUT);
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return ret;
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}
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/* i2c layer */
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static int diolan_usb_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
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int num)
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{
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struct i2c_diolan_u2c *dev = i2c_get_adapdata(adapter);
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struct i2c_msg *pmsg;
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int i, j;
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int ret, sret;
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ret = diolan_i2c_start(dev);
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if (ret < 0)
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return ret;
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for (i = 0; i < num; i++) {
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pmsg = &msgs[i];
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if (i) {
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ret = diolan_i2c_repeated_start(dev);
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if (ret < 0)
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goto abort;
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}
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if (pmsg->flags & I2C_M_RD) {
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ret =
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diolan_i2c_put_byte_ack(dev, (pmsg->addr << 1) | 1);
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if (ret < 0)
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goto abort;
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for (j = 0; j < pmsg->len; j++) {
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u8 byte;
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bool ack = j < pmsg->len - 1;
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/*
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* Don't send NACK if this is the first byte
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* of a SMBUS_BLOCK message.
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*/
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if (j == 0 && (pmsg->flags & I2C_M_RECV_LEN))
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ack = true;
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ret = diolan_i2c_get_byte_ack(dev, ack, &byte);
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if (ret < 0)
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goto abort;
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/*
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* Adjust count if first received byte is length
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*/
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if (j == 0 && (pmsg->flags & I2C_M_RECV_LEN)) {
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if (byte == 0
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|| byte > I2C_SMBUS_BLOCK_MAX) {
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ret = -EPROTO;
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goto abort;
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}
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pmsg->len += byte;
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}
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pmsg->buf[j] = byte;
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}
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} else {
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ret = diolan_i2c_put_byte_ack(dev, pmsg->addr << 1);
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if (ret < 0)
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goto abort;
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for (j = 0; j < pmsg->len; j++) {
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ret = diolan_i2c_put_byte_ack(dev,
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pmsg->buf[j]);
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if (ret < 0)
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goto abort;
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}
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}
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}
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abort:
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sret = diolan_i2c_stop(dev);
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if (sret < 0 && ret >= 0)
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ret = sret;
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return ret;
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}
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/*
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* Return list of supported functionality.
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*/
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static u32 diolan_usb_func(struct i2c_adapter *a)
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{
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return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
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I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
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}
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static const struct i2c_algorithm diolan_usb_algorithm = {
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.master_xfer = diolan_usb_xfer,
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.functionality = diolan_usb_func,
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};
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/* device layer */
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static const struct usb_device_id diolan_u2c_table[] = {
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{ USB_DEVICE(USB_VENDOR_ID_DIOLAN, USB_DEVICE_ID_DIOLAN_U2C) },
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{ }
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};
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MODULE_DEVICE_TABLE(usb, diolan_u2c_table);
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static void diolan_u2c_free(struct i2c_diolan_u2c *dev)
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{
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usb_put_dev(dev->usb_dev);
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kfree(dev);
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}
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static int diolan_u2c_probe(struct usb_interface *interface,
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const struct usb_device_id *id)
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{
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struct i2c_diolan_u2c *dev;
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int ret;
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/* allocate memory for our device state and initialize it */
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dev = kzalloc(sizeof(*dev), GFP_KERNEL);
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if (dev == NULL) {
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dev_err(&interface->dev, "no memory for device state\n");
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ret = -ENOMEM;
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goto error;
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}
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dev->usb_dev = usb_get_dev(interface_to_usbdev(interface));
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dev->interface = interface;
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/* save our data pointer in this interface device */
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usb_set_intfdata(interface, dev);
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/* setup i2c adapter description */
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dev->adapter.owner = THIS_MODULE;
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dev->adapter.class = I2C_CLASS_HWMON;
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dev->adapter.algo = &diolan_usb_algorithm;
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i2c_set_adapdata(&dev->adapter, dev);
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snprintf(dev->adapter.name, sizeof(dev->adapter.name),
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DRIVER_NAME " at bus %03d device %03d",
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dev->usb_dev->bus->busnum, dev->usb_dev->devnum);
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dev->adapter.dev.parent = &dev->interface->dev;
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/* initialize diolan i2c interface */
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ret = diolan_init(dev);
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if (ret < 0) {
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dev_err(&interface->dev, "failed to initialize adapter\n");
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goto error_free;
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}
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/* and finally attach to i2c layer */
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ret = i2c_add_adapter(&dev->adapter);
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if (ret < 0) {
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dev_err(&interface->dev, "failed to add I2C adapter\n");
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goto error_free;
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}
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|
dev_dbg(&interface->dev, "connected " DRIVER_NAME "\n");
|
|
|
|
return 0;
|
|
|
|
error_free:
|
|
usb_set_intfdata(interface, NULL);
|
|
diolan_u2c_free(dev);
|
|
error:
|
|
return ret;
|
|
}
|
|
|
|
static void diolan_u2c_disconnect(struct usb_interface *interface)
|
|
{
|
|
struct i2c_diolan_u2c *dev = usb_get_intfdata(interface);
|
|
|
|
i2c_del_adapter(&dev->adapter);
|
|
usb_set_intfdata(interface, NULL);
|
|
diolan_u2c_free(dev);
|
|
|
|
dev_dbg(&interface->dev, "disconnected\n");
|
|
}
|
|
|
|
static struct usb_driver diolan_u2c_driver = {
|
|
.name = DRIVER_NAME,
|
|
.probe = diolan_u2c_probe,
|
|
.disconnect = diolan_u2c_disconnect,
|
|
.id_table = diolan_u2c_table,
|
|
};
|
|
|
|
static int __init diolan_u2c_init(void)
|
|
{
|
|
/* register this driver with the USB subsystem */
|
|
return usb_register(&diolan_u2c_driver);
|
|
}
|
|
|
|
static void __exit diolan_u2c_exit(void)
|
|
{
|
|
/* deregister this driver with the USB subsystem */
|
|
usb_deregister(&diolan_u2c_driver);
|
|
}
|
|
|
|
module_init(diolan_u2c_init);
|
|
module_exit(diolan_u2c_exit);
|
|
|
|
MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>");
|
|
MODULE_DESCRIPTION(DRIVER_NAME " driver");
|
|
MODULE_LICENSE("GPL");
|