https://github.com/torvalds/linux
Tip revision: 9931faca02c604c22335f5a935a501bb2ace6e20 authored by Linus Torvalds on 10 January 2013, 02:59:55 UTC
Linux 3.8-rc3
Linux 3.8-rc3
Tip revision: 9931fac
cx25821-i2c.c
/*
* Driver for the Conexant CX25821 PCIe bridge
*
* Copyright (C) 2009 Conexant Systems Inc.
* Authors <shu.lin@conexant.com>, <hiep.huynh@conexant.com>
* Based on Steven Toth <stoth@linuxtv.org> cx23885 driver
*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include "cx25821.h"
#include <linux/i2c.h>
static unsigned int i2c_debug;
module_param(i2c_debug, int, 0644);
MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
static unsigned int i2c_scan;
module_param(i2c_scan, int, 0444);
MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
#define dprintk(level, fmt, arg...) \
do { \
if (i2c_debug >= level) \
printk(KERN_DEBUG "%s/0: " fmt, dev->name, ##arg); \
} while (0)
#define I2C_WAIT_DELAY 32
#define I2C_WAIT_RETRY 64
#define I2C_EXTEND (1 << 3)
#define I2C_NOSTOP (1 << 4)
static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap)
{
struct cx25821_i2c *bus = i2c_adap->algo_data;
struct cx25821_dev *dev = bus->dev;
return cx_read(bus->reg_stat) & 0x01;
}
static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
{
struct cx25821_i2c *bus = i2c_adap->algo_data;
struct cx25821_dev *dev = bus->dev;
return cx_read(bus->reg_stat) & 0x02 ? 1 : 0;
}
static int i2c_wait_done(struct i2c_adapter *i2c_adap)
{
int count;
for (count = 0; count < I2C_WAIT_RETRY; count++) {
if (!i2c_is_busy(i2c_adap))
break;
udelay(I2C_WAIT_DELAY);
}
if (I2C_WAIT_RETRY == count)
return 0;
return 1;
}
static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
const struct i2c_msg *msg, int joined_rlen)
{
struct cx25821_i2c *bus = i2c_adap->algo_data;
struct cx25821_dev *dev = bus->dev;
u32 wdata, addr, ctrl;
int retval, cnt;
if (joined_rlen)
dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__,
msg->len, joined_rlen);
else
dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);
/* Deal with i2c probe functions with zero payload */
if (msg->len == 0) {
cx_write(bus->reg_addr, msg->addr << 25);
cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2));
if (!i2c_wait_done(i2c_adap))
return -EIO;
if (!i2c_slave_did_ack(i2c_adap))
return -EIO;
dprintk(1, "%s(): returns 0\n", __func__);
return 0;
}
/* dev, reg + first byte */
addr = (msg->addr << 25) | msg->buf[0];
wdata = msg->buf[0];
ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
if (msg->len > 1)
ctrl |= I2C_NOSTOP | I2C_EXTEND;
else if (joined_rlen)
ctrl |= I2C_NOSTOP;
cx_write(bus->reg_addr, addr);
cx_write(bus->reg_wdata, wdata);
cx_write(bus->reg_ctrl, ctrl);
retval = i2c_wait_done(i2c_adap);
if (retval < 0)
goto err;
if (retval == 0)
goto eio;
if (i2c_debug) {
if (!(ctrl & I2C_NOSTOP))
printk(" >\n");
}
for (cnt = 1; cnt < msg->len; cnt++) {
/* following bytes */
wdata = msg->buf[cnt];
ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
if (cnt < msg->len - 1)
ctrl |= I2C_NOSTOP | I2C_EXTEND;
else if (joined_rlen)
ctrl |= I2C_NOSTOP;
cx_write(bus->reg_addr, addr);
cx_write(bus->reg_wdata, wdata);
cx_write(bus->reg_ctrl, ctrl);
retval = i2c_wait_done(i2c_adap);
if (retval < 0)
goto err;
if (retval == 0)
goto eio;
if (i2c_debug) {
dprintk(1, " %02x", msg->buf[cnt]);
if (!(ctrl & I2C_NOSTOP))
dprintk(1, " >\n");
}
}
return msg->len;
eio:
retval = -EIO;
err:
if (i2c_debug)
pr_err(" ERR: %d\n", retval);
return retval;
}
static int i2c_readbytes(struct i2c_adapter *i2c_adap,
const struct i2c_msg *msg, int joined)
{
struct cx25821_i2c *bus = i2c_adap->algo_data;
struct cx25821_dev *dev = bus->dev;
u32 ctrl, cnt;
int retval;
if (i2c_debug && !joined)
dprintk(1, "6-%s(msg->len=%d)\n", __func__, msg->len);
/* Deal with i2c probe functions with zero payload */
if (msg->len == 0) {
cx_write(bus->reg_addr, msg->addr << 25);
cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1);
if (!i2c_wait_done(i2c_adap))
return -EIO;
if (!i2c_slave_did_ack(i2c_adap))
return -EIO;
dprintk(1, "%s(): returns 0\n", __func__);
return 0;
}
if (i2c_debug) {
if (joined)
dprintk(1, " R");
else
dprintk(1, " <R %02x", (msg->addr << 1) + 1);
}
for (cnt = 0; cnt < msg->len; cnt++) {
ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1;
if (cnt < msg->len - 1)
ctrl |= I2C_NOSTOP | I2C_EXTEND;
cx_write(bus->reg_addr, msg->addr << 25);
cx_write(bus->reg_ctrl, ctrl);
retval = i2c_wait_done(i2c_adap);
if (retval < 0)
goto err;
if (retval == 0)
goto eio;
msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;
if (i2c_debug) {
dprintk(1, " %02x", msg->buf[cnt]);
if (!(ctrl & I2C_NOSTOP))
dprintk(1, " >\n");
}
}
return msg->len;
eio:
retval = -EIO;
err:
if (i2c_debug)
pr_err(" ERR: %d\n", retval);
return retval;
}
static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
{
struct cx25821_i2c *bus = i2c_adap->algo_data;
struct cx25821_dev *dev = bus->dev;
int i, retval = 0;
dprintk(1, "%s(num = %d)\n", __func__, num);
for (i = 0; i < num; i++) {
dprintk(1, "%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) {
/* read */
retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
} 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 = i2c_sendbytes(i2c_adap, &msgs[i],
msgs[i + 1].len);
if (retval < 0)
goto err;
i++;
retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
} else {
/* write */
retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
}
if (retval < 0)
goto err;
}
return num;
err:
return retval;
}
static u32 cx25821_functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C | I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_READ_WORD_DATA | I2C_FUNC_SMBUS_WRITE_WORD_DATA;
}
static struct i2c_algorithm cx25821_i2c_algo_template = {
.master_xfer = i2c_xfer,
.functionality = cx25821_functionality,
#ifdef NEED_ALGO_CONTROL
.algo_control = dummy_algo_control,
#endif
};
static struct i2c_adapter cx25821_i2c_adap_template = {
.name = "cx25821",
.owner = THIS_MODULE,
.algo = &cx25821_i2c_algo_template,
};
static struct i2c_client cx25821_i2c_client_template = {
.name = "cx25821 internal",
};
/* init + register i2c adapter */
int cx25821_i2c_register(struct cx25821_i2c *bus)
{
struct cx25821_dev *dev = bus->dev;
dprintk(1, "%s(bus = %d)\n", __func__, bus->nr);
bus->i2c_adap = cx25821_i2c_adap_template;
bus->i2c_client = cx25821_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, &dev->v4l2_dev);
i2c_add_adapter(&bus->i2c_adap);
bus->i2c_client.adapter = &bus->i2c_adap;
/* set up the I2c */
bus->i2c_client.addr = (0x88 >> 1);
return bus->i2c_rc;
}
int cx25821_i2c_unregister(struct cx25821_i2c *bus)
{
i2c_del_adapter(&bus->i2c_adap);
return 0;
}
#if 0 /* Currently unused */
static void cx25821_av_clk(struct cx25821_dev *dev, int enable)
{
/* write 0 to bus 2 addr 0x144 via i2x_xfer() */
char buffer[3];
struct i2c_msg msg;
dprintk(1, "%s(enabled = %d)\n", __func__, enable);
/* Register 0x144 */
buffer[0] = 0x01;
buffer[1] = 0x44;
if (enable == 1)
buffer[2] = 0x05;
else
buffer[2] = 0x00;
msg.addr = 0x44;
msg.flags = I2C_M_TEN;
msg.len = 3;
msg.buf = buffer;
i2c_xfer(&dev->i2c_bus[0].i2c_adap, &msg, 1);
}
#endif
int cx25821_i2c_read(struct cx25821_i2c *bus, u16 reg_addr, int *value)
{
struct i2c_client *client = &bus->i2c_client;
int v = 0;
u8 addr[2] = { 0, 0 };
u8 buf[4] = { 0, 0, 0, 0 };
struct i2c_msg msgs[2] = {
{
.addr = client->addr,
.flags = 0,
.len = 2,
.buf = addr,
}, {
.addr = client->addr,
.flags = I2C_M_RD,
.len = 4,
.buf = buf,
}
};
addr[0] = (reg_addr >> 8);
addr[1] = (reg_addr & 0xff);
msgs[0].addr = 0x44;
msgs[1].addr = 0x44;
i2c_xfer(client->adapter, msgs, 2);
v = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
*value = v;
return v;
}
int cx25821_i2c_write(struct cx25821_i2c *bus, u16 reg_addr, int value)
{
struct i2c_client *client = &bus->i2c_client;
int retval = 0;
u8 buf[6] = { 0, 0, 0, 0, 0, 0 };
struct i2c_msg msgs[1] = {
{
.addr = client->addr,
.flags = 0,
.len = 6,
.buf = buf,
}
};
buf[0] = reg_addr >> 8;
buf[1] = reg_addr & 0xff;
buf[5] = (value >> 24) & 0xff;
buf[4] = (value >> 16) & 0xff;
buf[3] = (value >> 8) & 0xff;
buf[2] = value & 0xff;
client->flags = 0;
msgs[0].addr = 0x44;
retval = i2c_xfer(client->adapter, msgs, 1);
return retval;
}