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7d58d1117e
Issuing register reads as a separate address write and data read transactions means that other I2C activity could occur in between and state could get out of sync. Issue both the write and read in a single transaction so that the i2c layer can prevent other users accessing the bus until we are complete. Signed-off-by: Chris Pascoe <c.pascoe@itee.uq.edu.au> Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
90 lines
2.7 KiB
C
90 lines
2.7 KiB
C
/*
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tuner-i2c.h - i2c interface for different tuners
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Copyright (C) 2007 Michael Krufky (mkrufky@linuxtv.org)
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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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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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GNU General Public License for more details.
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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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#ifndef __TUNER_I2C_H__
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#define __TUNER_I2C_H__
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#include <linux/i2c.h>
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struct tuner_i2c_props {
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u8 addr;
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struct i2c_adapter *adap;
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};
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static inline int tuner_i2c_xfer_send(struct tuner_i2c_props *props, char *buf, int len)
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{
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struct i2c_msg msg = { .addr = props->addr, .flags = 0,
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.buf = buf, .len = len };
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int ret = i2c_transfer(props->adap, &msg, 1);
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return (ret == 1) ? len : ret;
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}
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static inline int tuner_i2c_xfer_recv(struct tuner_i2c_props *props, char *buf, int len)
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{
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struct i2c_msg msg = { .addr = props->addr, .flags = I2C_M_RD,
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.buf = buf, .len = len };
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int ret = i2c_transfer(props->adap, &msg, 1);
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return (ret == 1) ? len : ret;
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}
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static inline int tuner_i2c_xfer_send_recv(struct tuner_i2c_props *props,
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char *obuf, int olen,
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char *ibuf, int ilen)
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{
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struct i2c_msg msg[2] = { { .addr = props->addr, .flags = 0,
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.buf = obuf, .len = olen },
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{ .addr = props->addr, .flags = I2C_M_RD,
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.buf = ibuf, .len = ilen } };
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int ret = i2c_transfer(props->adap, msg, 2);
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return (ret == 2) ? ilen : ret;
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}
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#ifndef __TUNER_DRIVER_H__
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#define tuner_warn(fmt, arg...) do { \
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printk(KERN_WARNING "%s %d-%04x: " fmt, PREFIX, \
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i2c_adapter_id(priv->i2c_props.adap), \
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priv->i2c_props.addr, ##arg); \
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} while (0)
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#define tuner_info(fmt, arg...) do { \
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printk(KERN_INFO "%s %d-%04x: " fmt, PREFIX, \
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i2c_adapter_id(priv->i2c_props.adap), \
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priv->i2c_props.addr , ##arg); \
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} while (0)
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#define tuner_err(fmt, arg...) do { \
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printk(KERN_ERR "%s %d-%04x: " fmt, PREFIX, \
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i2c_adapter_id(priv->i2c_props.adap), \
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priv->i2c_props.addr , ##arg); \
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} while (0)
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#define tuner_dbg(fmt, arg...) do { \
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if ((debug)) \
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printk(KERN_DEBUG "%s %d-%04x: " fmt, PREFIX, \
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i2c_adapter_id(priv->i2c_props.adap), \
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priv->i2c_props.addr , ##arg); \
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} while (0)
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#endif /* __TUNER_DRIVER_H__ */
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#endif /* __TUNER_I2C_H__ */
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