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a824f0f445
There's one comment that has been copied from bttv to many other media/video drivers: /* init + register i2c algo-bit adapter */ Meanwhile, many drivers use hardware I2C implementations instead of relying on i2c-algo-bit, so this comment is misleading. Remove the reference to "algo-bit" from all drivers, to avoid any confusion. This is the best way to ensure that the comments won't go out of sync again. Anyone interested in the implementation details would rather look at the code itself. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
390 lines
9 KiB
C
390 lines
9 KiB
C
/*
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* Driver for the Auvitek AU0828 USB bridge
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*
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* Copyright (c) 2008 Steven Toth <stoth@linuxtv.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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*
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/init.h>
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#include <linux/delay.h>
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#include <linux/io.h>
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#include "au0828.h"
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#include <media/v4l2-common.h>
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static int i2c_scan;
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module_param(i2c_scan, int, 0444);
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MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
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#define I2C_WAIT_DELAY 512
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#define I2C_WAIT_RETRY 64
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static inline int i2c_slave_did_write_ack(struct i2c_adapter *i2c_adap)
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{
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struct au0828_dev *dev = i2c_adap->algo_data;
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return au0828_read(dev, AU0828_I2C_STATUS_201) &
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AU0828_I2C_STATUS_NO_WRITE_ACK ? 0 : 1;
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}
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static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
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{
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struct au0828_dev *dev = i2c_adap->algo_data;
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return au0828_read(dev, AU0828_I2C_STATUS_201) &
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AU0828_I2C_STATUS_NO_READ_ACK ? 0 : 1;
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}
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static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
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{
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int count;
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for (count = 0; count < I2C_WAIT_RETRY; count++) {
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if (!i2c_slave_did_read_ack(i2c_adap))
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break;
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udelay(I2C_WAIT_DELAY);
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}
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if (I2C_WAIT_RETRY == count)
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return 0;
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return 1;
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}
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static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
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{
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struct au0828_dev *dev = i2c_adap->algo_data;
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return au0828_read(dev, AU0828_I2C_STATUS_201) &
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AU0828_I2C_STATUS_READ_DONE ? 0 : 1;
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}
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static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
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{
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int count;
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for (count = 0; count < I2C_WAIT_RETRY; count++) {
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if (!i2c_is_read_busy(i2c_adap))
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break;
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udelay(I2C_WAIT_DELAY);
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}
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if (I2C_WAIT_RETRY == count)
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return 0;
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return 1;
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}
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static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
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{
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struct au0828_dev *dev = i2c_adap->algo_data;
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return au0828_read(dev, AU0828_I2C_STATUS_201) &
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AU0828_I2C_STATUS_WRITE_DONE ? 1 : 0;
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}
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static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
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{
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int count;
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for (count = 0; count < I2C_WAIT_RETRY; count++) {
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if (i2c_is_write_done(i2c_adap))
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break;
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udelay(I2C_WAIT_DELAY);
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}
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if (I2C_WAIT_RETRY == count)
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return 0;
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return 1;
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}
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static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
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{
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struct au0828_dev *dev = i2c_adap->algo_data;
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return au0828_read(dev, AU0828_I2C_STATUS_201) &
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AU0828_I2C_STATUS_BUSY ? 1 : 0;
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}
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static int i2c_wait_done(struct i2c_adapter *i2c_adap)
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{
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int count;
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for (count = 0; count < I2C_WAIT_RETRY; count++) {
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if (!i2c_is_busy(i2c_adap))
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break;
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udelay(I2C_WAIT_DELAY);
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}
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if (I2C_WAIT_RETRY == count)
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return 0;
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return 1;
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}
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/* FIXME: Implement join handling correctly */
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static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
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const struct i2c_msg *msg, int joined_rlen)
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{
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int i, strobe = 0;
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struct au0828_dev *dev = i2c_adap->algo_data;
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dprintk(4, "%s()\n", __func__);
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au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
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/* Set the I2C clock */
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au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
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dev->board.i2c_clk_divider);
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/* Hardware needs 8 bit addresses */
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au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
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dprintk(4, "SEND: %02x\n", msg->addr);
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/* Deal with i2c_scan */
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if (msg->len == 0) {
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/* The analog tuner detection code makes use of the SMBUS_QUICK
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message (which involves a zero length i2c write). To avoid
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checking the status register when we didn't strobe out any
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actual bytes to the bus, just do a read check. This is
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consistent with how I saw i2c device checking done in the
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USB trace of the Windows driver */
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au0828_write(dev, AU0828_I2C_TRIGGER_200,
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AU0828_I2C_TRIGGER_READ);
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if (!i2c_wait_done(i2c_adap))
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return -EIO;
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if (i2c_wait_read_ack(i2c_adap))
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return -EIO;
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return 0;
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}
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for (i = 0; i < msg->len;) {
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dprintk(4, " %02x\n", msg->buf[i]);
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au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]);
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strobe++;
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i++;
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if ((strobe >= 4) || (i >= msg->len)) {
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/* Strobe the byte into the bus */
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if (i < msg->len)
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au0828_write(dev, AU0828_I2C_TRIGGER_200,
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AU0828_I2C_TRIGGER_WRITE |
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AU0828_I2C_TRIGGER_HOLD);
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else
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au0828_write(dev, AU0828_I2C_TRIGGER_200,
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AU0828_I2C_TRIGGER_WRITE);
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/* Reset strobe trigger */
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strobe = 0;
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if (!i2c_wait_write_done(i2c_adap))
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return -EIO;
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}
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}
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if (!i2c_wait_done(i2c_adap))
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return -EIO;
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dprintk(4, "\n");
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return msg->len;
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}
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/* FIXME: Implement join handling correctly */
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static int i2c_readbytes(struct i2c_adapter *i2c_adap,
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const struct i2c_msg *msg, int joined)
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{
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struct au0828_dev *dev = i2c_adap->algo_data;
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int i;
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dprintk(4, "%s()\n", __func__);
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au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
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/* Set the I2C clock */
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au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
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dev->board.i2c_clk_divider);
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/* Hardware needs 8 bit addresses */
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au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
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dprintk(4, " RECV:\n");
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/* Deal with i2c_scan */
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if (msg->len == 0) {
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au0828_write(dev, AU0828_I2C_TRIGGER_200,
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AU0828_I2C_TRIGGER_READ);
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if (i2c_wait_read_ack(i2c_adap))
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return -EIO;
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return 0;
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}
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for (i = 0; i < msg->len;) {
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i++;
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if (i < msg->len)
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au0828_write(dev, AU0828_I2C_TRIGGER_200,
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AU0828_I2C_TRIGGER_READ |
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AU0828_I2C_TRIGGER_HOLD);
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else
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au0828_write(dev, AU0828_I2C_TRIGGER_200,
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AU0828_I2C_TRIGGER_READ);
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if (!i2c_wait_read_done(i2c_adap))
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return -EIO;
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msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
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0xff;
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dprintk(4, " %02x\n", msg->buf[i-1]);
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}
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if (!i2c_wait_done(i2c_adap))
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return -EIO;
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dprintk(4, "\n");
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return msg->len;
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}
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static int i2c_xfer(struct i2c_adapter *i2c_adap,
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struct i2c_msg *msgs, int num)
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{
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int i, retval = 0;
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dprintk(4, "%s(num = %d)\n", __func__, num);
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for (i = 0; i < num; i++) {
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dprintk(4, "%s(num = %d) addr = 0x%02x len = 0x%x\n",
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__func__, num, msgs[i].addr, msgs[i].len);
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if (msgs[i].flags & I2C_M_RD) {
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/* read */
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retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
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} else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
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msgs[i].addr == msgs[i + 1].addr) {
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/* write then read from same address */
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retval = i2c_sendbytes(i2c_adap, &msgs[i],
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msgs[i + 1].len);
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if (retval < 0)
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goto err;
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i++;
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retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
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} else {
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/* write */
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retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
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}
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if (retval < 0)
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goto err;
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}
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return num;
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err:
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return retval;
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}
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static u32 au0828_functionality(struct i2c_adapter *adap)
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{
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return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
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}
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static struct i2c_algorithm au0828_i2c_algo_template = {
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.master_xfer = i2c_xfer,
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.functionality = au0828_functionality,
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};
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/* ----------------------------------------------------------------------- */
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static struct i2c_adapter au0828_i2c_adap_template = {
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.name = DRIVER_NAME,
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.owner = THIS_MODULE,
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.algo = &au0828_i2c_algo_template,
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};
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static struct i2c_client au0828_i2c_client_template = {
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.name = "au0828 internal",
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};
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static char *i2c_devs[128] = {
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[0x8e >> 1] = "au8522",
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[0xa0 >> 1] = "eeprom",
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[0xc2 >> 1] = "tuner/xc5000",
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};
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static void do_i2c_scan(char *name, struct i2c_client *c)
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{
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unsigned char buf;
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int i, rc;
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for (i = 0; i < 128; i++) {
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c->addr = i;
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rc = i2c_master_recv(c, &buf, 0);
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if (rc < 0)
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continue;
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printk(KERN_INFO "%s: i2c scan: found device @ 0x%x [%s]\n",
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name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
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}
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}
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/* init + register i2c adapter */
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int au0828_i2c_register(struct au0828_dev *dev)
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{
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dprintk(1, "%s()\n", __func__);
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memcpy(&dev->i2c_adap, &au0828_i2c_adap_template,
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sizeof(dev->i2c_adap));
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memcpy(&dev->i2c_algo, &au0828_i2c_algo_template,
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sizeof(dev->i2c_algo));
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memcpy(&dev->i2c_client, &au0828_i2c_client_template,
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sizeof(dev->i2c_client));
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dev->i2c_adap.dev.parent = &dev->usbdev->dev;
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strlcpy(dev->i2c_adap.name, DRIVER_NAME,
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sizeof(dev->i2c_adap.name));
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dev->i2c_adap.algo = &dev->i2c_algo;
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dev->i2c_adap.algo_data = dev;
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i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
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i2c_add_adapter(&dev->i2c_adap);
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dev->i2c_client.adapter = &dev->i2c_adap;
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if (0 == dev->i2c_rc) {
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printk(KERN_INFO "%s: i2c bus registered\n", DRIVER_NAME);
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if (i2c_scan)
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do_i2c_scan(DRIVER_NAME, &dev->i2c_client);
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} else
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printk(KERN_INFO "%s: i2c bus register FAILED\n", DRIVER_NAME);
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return dev->i2c_rc;
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}
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int au0828_i2c_unregister(struct au0828_dev *dev)
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{
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i2c_del_adapter(&dev->i2c_adap);
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return 0;
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}
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