linux/drivers/media/pci/saa7164/saa7164-i2c.c

127 lines
3.3 KiB
C

/*
* 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)\n", __func__, num);
for (i = 0 ; i < num; i++) {
dprintk(DBGLVL_I2C, "%s(num = %d) addr = 0x%02x len = 0x%x\n",
__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)\n", __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\n",
dev->name, bus->nr);
return bus->i2c_rc;
}
int saa7164_i2c_unregister(struct saa7164_i2c *bus)
{
i2c_del_adapter(&bus->i2c_adap);
return 0;
}