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kernel/linux-rt-4.4.41/drivers/media/pci/saa7164/saa7164-i2c.c 3.25 KB
5113f6f70   김현기   kernel add
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  /*
   *  Driver for the NXP SAA7164 PCIe bridge
   *
   *  Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com>
   *
   *  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.
   *
   *  This program is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *  along with this program; if not, write to the Free Software
   *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  #include <linux/module.h>
  #include <linux/moduleparam.h>
  #include <linux/init.h>
  #include <linux/delay.h>
  #include <linux/io.h>
  
  #include "saa7164.h"
  
  static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
  {
  	struct saa7164_i2c *bus = i2c_adap->algo_data;
  	struct saa7164_dev *dev = bus->dev;
  	int i, retval = 0;
  
  	dprintk(DBGLVL_I2C, "%s(num = %d)
  ", __func__, num);
  
  	for (i = 0 ; i < num; i++) {
  		dprintk(DBGLVL_I2C, "%s(num = %d) addr = 0x%02x  len = 0x%x
  ",
  			__func__, num, msgs[i].addr, msgs[i].len);
  		if (msgs[i].flags & I2C_M_RD) {
  			retval = saa7164_api_i2c_read(bus,
  				msgs[i].addr,
  				0 /* reglen */,
  				NULL /* reg */, msgs[i].len, msgs[i].buf);
  		} else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
  			   msgs[i].addr == msgs[i + 1].addr) {
  			/* write then read from same address */
  
  			retval = saa7164_api_i2c_read(bus, msgs[i].addr,
  				msgs[i].len, msgs[i].buf,
  				msgs[i+1].len, msgs[i+1].buf
  				);
  
  			i++;
  
  			if (retval < 0)
  				goto err;
  		} else {
  			/* write */
  			retval = saa7164_api_i2c_write(bus, msgs[i].addr,
  				msgs[i].len, msgs[i].buf);
  		}
  		if (retval < 0)
  			goto err;
  	}
  	return num;
  
  err:
  	return retval;
  }
  
  static u32 saa7164_functionality(struct i2c_adapter *adap)
  {
  	return I2C_FUNC_I2C;
  }
  
  static struct i2c_algorithm saa7164_i2c_algo_template = {
  	.master_xfer	= i2c_xfer,
  	.functionality	= saa7164_functionality,
  };
  
  /* ----------------------------------------------------------------------- */
  
  static struct i2c_adapter saa7164_i2c_adap_template = {
  	.name              = "saa7164",
  	.owner             = THIS_MODULE,
  	.algo              = &saa7164_i2c_algo_template,
  };
  
  static struct i2c_client saa7164_i2c_client_template = {
  	.name	= "saa7164 internal",
  };
  
  int saa7164_i2c_register(struct saa7164_i2c *bus)
  {
  	struct saa7164_dev *dev = bus->dev;
  
  	dprintk(DBGLVL_I2C, "%s(bus = %d)
  ", __func__, bus->nr);
  
  	bus->i2c_adap = saa7164_i2c_adap_template;
  	bus->i2c_client = saa7164_i2c_client_template;
  
  	bus->i2c_adap.dev.parent = &dev->pci->dev;
  
  	strlcpy(bus->i2c_adap.name, bus->dev->name,
  		sizeof(bus->i2c_adap.name));
  
  	bus->i2c_adap.algo_data = bus;
  	i2c_set_adapdata(&bus->i2c_adap, bus);
  	i2c_add_adapter(&bus->i2c_adap);
  
  	bus->i2c_client.adapter = &bus->i2c_adap;
  
  	if (0 != bus->i2c_rc)
  		printk(KERN_ERR "%s: i2c bus %d register FAILED
  ",
  			dev->name, bus->nr);
  
  	return bus->i2c_rc;
  }
  
  int saa7164_i2c_unregister(struct saa7164_i2c *bus)
  {
  	i2c_del_adapter(&bus->i2c_adap);
  	return 0;
  }