mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
![Jan Engelhardt](/assets/img/avatar_default.png)
* Convert files to UTF-8. * Also correct some people's names (one example is Eißfeldt, which was found in a source file. Given that the author used an ß at all in a source file indicates that the real name has in fact a 'ß' and not an 'ss', which is commonly used as a substitute for 'ß' when limited to 7bit.) * Correct town names (Goettingen -> Göttingen) * Update Eberhard Mönkeberg's address (http://lkml.org/lkml/2007/1/8/313) Signed-off-by: Jan Engelhardt <jengelh@gmx.de> Signed-off-by: Adrian Bunk <bunk@kernel.org>
390 lines
9.9 KiB
C
390 lines
9.9 KiB
C
/*
|
|
* i2c-algo-pca.c i2c driver algorithms for PCA9564 adapters
|
|
* Copyright (C) 2004 Arcom Control Systems
|
|
*
|
|
* 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/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/init.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/i2c-algo-pca.h>
|
|
#include "i2c-algo-pca.h"
|
|
|
|
#define DRIVER "i2c-algo-pca"
|
|
|
|
#define DEB1(fmt, args...) do { if (i2c_debug>=1) printk(fmt, ## args); } while(0)
|
|
#define DEB2(fmt, args...) do { if (i2c_debug>=2) printk(fmt, ## args); } while(0)
|
|
#define DEB3(fmt, args...) do { if (i2c_debug>=3) printk(fmt, ## args); } while(0)
|
|
|
|
static int i2c_debug;
|
|
|
|
#define pca_outw(adap, reg, val) adap->write_byte(adap, reg, val)
|
|
#define pca_inw(adap, reg) adap->read_byte(adap, reg)
|
|
|
|
#define pca_status(adap) pca_inw(adap, I2C_PCA_STA)
|
|
#define pca_clock(adap) adap->get_clock(adap)
|
|
#define pca_own(adap) adap->get_own(adap)
|
|
#define pca_set_con(adap, val) pca_outw(adap, I2C_PCA_CON, val)
|
|
#define pca_get_con(adap) pca_inw(adap, I2C_PCA_CON)
|
|
#define pca_wait(adap) adap->wait_for_interrupt(adap)
|
|
|
|
/*
|
|
* Generate a start condition on the i2c bus.
|
|
*
|
|
* returns after the start condition has occurred
|
|
*/
|
|
static void pca_start(struct i2c_algo_pca_data *adap)
|
|
{
|
|
int sta = pca_get_con(adap);
|
|
DEB2("=== START\n");
|
|
sta |= I2C_PCA_CON_STA;
|
|
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
|
|
pca_set_con(adap, sta);
|
|
pca_wait(adap);
|
|
}
|
|
|
|
/*
|
|
* Generate a repeated start condition on the i2c bus
|
|
*
|
|
* return after the repeated start condition has occurred
|
|
*/
|
|
static void pca_repeated_start(struct i2c_algo_pca_data *adap)
|
|
{
|
|
int sta = pca_get_con(adap);
|
|
DEB2("=== REPEATED START\n");
|
|
sta |= I2C_PCA_CON_STA;
|
|
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
|
|
pca_set_con(adap, sta);
|
|
pca_wait(adap);
|
|
}
|
|
|
|
/*
|
|
* Generate a stop condition on the i2c bus
|
|
*
|
|
* returns after the stop condition has been generated
|
|
*
|
|
* STOPs do not generate an interrupt or set the SI flag, since the
|
|
* part returns the idle state (0xf8). Hence we don't need to
|
|
* pca_wait here.
|
|
*/
|
|
static void pca_stop(struct i2c_algo_pca_data *adap)
|
|
{
|
|
int sta = pca_get_con(adap);
|
|
DEB2("=== STOP\n");
|
|
sta |= I2C_PCA_CON_STO;
|
|
sta &= ~(I2C_PCA_CON_STA|I2C_PCA_CON_SI);
|
|
pca_set_con(adap, sta);
|
|
}
|
|
|
|
/*
|
|
* Send the slave address and R/W bit
|
|
*
|
|
* returns after the address has been sent
|
|
*/
|
|
static void pca_address(struct i2c_algo_pca_data *adap,
|
|
struct i2c_msg *msg)
|
|
{
|
|
int sta = pca_get_con(adap);
|
|
int addr;
|
|
|
|
addr = ( (0x7f & msg->addr) << 1 );
|
|
if (msg->flags & I2C_M_RD )
|
|
addr |= 1;
|
|
DEB2("=== SLAVE ADDRESS %#04x+%c=%#04x\n",
|
|
msg->addr, msg->flags & I2C_M_RD ? 'R' : 'W', addr);
|
|
|
|
pca_outw(adap, I2C_PCA_DAT, addr);
|
|
|
|
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
|
|
pca_set_con(adap, sta);
|
|
|
|
pca_wait(adap);
|
|
}
|
|
|
|
/*
|
|
* Transmit a byte.
|
|
*
|
|
* Returns after the byte has been transmitted
|
|
*/
|
|
static void pca_tx_byte(struct i2c_algo_pca_data *adap,
|
|
__u8 b)
|
|
{
|
|
int sta = pca_get_con(adap);
|
|
DEB2("=== WRITE %#04x\n", b);
|
|
pca_outw(adap, I2C_PCA_DAT, b);
|
|
|
|
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
|
|
pca_set_con(adap, sta);
|
|
|
|
pca_wait(adap);
|
|
}
|
|
|
|
/*
|
|
* Receive a byte
|
|
*
|
|
* returns immediately.
|
|
*/
|
|
static void pca_rx_byte(struct i2c_algo_pca_data *adap,
|
|
__u8 *b, int ack)
|
|
{
|
|
*b = pca_inw(adap, I2C_PCA_DAT);
|
|
DEB2("=== READ %#04x %s\n", *b, ack ? "ACK" : "NACK");
|
|
}
|
|
|
|
/*
|
|
* Setup ACK or NACK for next received byte and wait for it to arrive.
|
|
*
|
|
* Returns after next byte has arrived.
|
|
*/
|
|
static void pca_rx_ack(struct i2c_algo_pca_data *adap,
|
|
int ack)
|
|
{
|
|
int sta = pca_get_con(adap);
|
|
|
|
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI|I2C_PCA_CON_AA);
|
|
|
|
if ( ack )
|
|
sta |= I2C_PCA_CON_AA;
|
|
|
|
pca_set_con(adap, sta);
|
|
pca_wait(adap);
|
|
}
|
|
|
|
/*
|
|
* Reset the i2c bus / SIO
|
|
*/
|
|
static void pca_reset(struct i2c_algo_pca_data *adap)
|
|
{
|
|
/* apparently only an external reset will do it. not a lot can be done */
|
|
printk(KERN_ERR DRIVER ": Haven't figured out how to do a reset yet\n");
|
|
}
|
|
|
|
static int pca_xfer(struct i2c_adapter *i2c_adap,
|
|
struct i2c_msg *msgs,
|
|
int num)
|
|
{
|
|
struct i2c_algo_pca_data *adap = i2c_adap->algo_data;
|
|
struct i2c_msg *msg = NULL;
|
|
int curmsg;
|
|
int numbytes = 0;
|
|
int state;
|
|
int ret;
|
|
int timeout = 100;
|
|
|
|
while ((state = pca_status(adap)) != 0xf8 && timeout--) {
|
|
msleep(10);
|
|
}
|
|
if (state != 0xf8) {
|
|
dev_dbg(&i2c_adap->dev, "bus is not idle. status is %#04x\n", state);
|
|
return -EIO;
|
|
}
|
|
|
|
DEB1("{{{ XFER %d messages\n", num);
|
|
|
|
if (i2c_debug>=2) {
|
|
for (curmsg = 0; curmsg < num; curmsg++) {
|
|
int addr, i;
|
|
msg = &msgs[curmsg];
|
|
|
|
addr = (0x7f & msg->addr) ;
|
|
|
|
if (msg->flags & I2C_M_RD )
|
|
printk(KERN_INFO " [%02d] RD %d bytes from %#02x [%#02x, ...]\n",
|
|
curmsg, msg->len, addr, (addr<<1) | 1);
|
|
else {
|
|
printk(KERN_INFO " [%02d] WR %d bytes to %#02x [%#02x%s",
|
|
curmsg, msg->len, addr, addr<<1,
|
|
msg->len == 0 ? "" : ", ");
|
|
for(i=0; i < msg->len; i++)
|
|
printk("%#04x%s", msg->buf[i], i == msg->len - 1 ? "" : ", ");
|
|
printk("]\n");
|
|
}
|
|
}
|
|
}
|
|
|
|
curmsg = 0;
|
|
ret = -EREMOTEIO;
|
|
while (curmsg < num) {
|
|
state = pca_status(adap);
|
|
|
|
DEB3("STATE is 0x%02x\n", state);
|
|
msg = &msgs[curmsg];
|
|
|
|
switch (state) {
|
|
case 0xf8: /* On reset or stop the bus is idle */
|
|
pca_start(adap);
|
|
break;
|
|
|
|
case 0x08: /* A START condition has been transmitted */
|
|
case 0x10: /* A repeated start condition has been transmitted */
|
|
pca_address(adap, msg);
|
|
break;
|
|
|
|
case 0x18: /* SLA+W has been transmitted; ACK has been received */
|
|
case 0x28: /* Data byte in I2CDAT has been transmitted; ACK has been received */
|
|
if (numbytes < msg->len) {
|
|
pca_tx_byte(adap, msg->buf[numbytes]);
|
|
numbytes++;
|
|
break;
|
|
}
|
|
curmsg++; numbytes = 0;
|
|
if (curmsg == num)
|
|
pca_stop(adap);
|
|
else
|
|
pca_repeated_start(adap);
|
|
break;
|
|
|
|
case 0x20: /* SLA+W has been transmitted; NOT ACK has been received */
|
|
DEB2("NOT ACK received after SLA+W\n");
|
|
pca_stop(adap);
|
|
goto out;
|
|
|
|
case 0x40: /* SLA+R has been transmitted; ACK has been received */
|
|
pca_rx_ack(adap, msg->len > 1);
|
|
break;
|
|
|
|
case 0x50: /* Data bytes has been received; ACK has been returned */
|
|
if (numbytes < msg->len) {
|
|
pca_rx_byte(adap, &msg->buf[numbytes], 1);
|
|
numbytes++;
|
|
pca_rx_ack(adap, numbytes < msg->len - 1);
|
|
break;
|
|
}
|
|
curmsg++; numbytes = 0;
|
|
if (curmsg == num)
|
|
pca_stop(adap);
|
|
else
|
|
pca_repeated_start(adap);
|
|
break;
|
|
|
|
case 0x48: /* SLA+R has been transmitted; NOT ACK has been received */
|
|
DEB2("NOT ACK received after SLA+R\n");
|
|
pca_stop(adap);
|
|
goto out;
|
|
|
|
case 0x30: /* Data byte in I2CDAT has been transmitted; NOT ACK has been received */
|
|
DEB2("NOT ACK received after data byte\n");
|
|
goto out;
|
|
|
|
case 0x38: /* Arbitration lost during SLA+W, SLA+R or data bytes */
|
|
DEB2("Arbitration lost\n");
|
|
goto out;
|
|
|
|
case 0x58: /* Data byte has been received; NOT ACK has been returned */
|
|
if ( numbytes == msg->len - 1 ) {
|
|
pca_rx_byte(adap, &msg->buf[numbytes], 0);
|
|
curmsg++; numbytes = 0;
|
|
if (curmsg == num)
|
|
pca_stop(adap);
|
|
else
|
|
pca_repeated_start(adap);
|
|
} else {
|
|
DEB2("NOT ACK sent after data byte received. "
|
|
"Not final byte. numbytes %d. len %d\n",
|
|
numbytes, msg->len);
|
|
pca_stop(adap);
|
|
goto out;
|
|
}
|
|
break;
|
|
case 0x70: /* Bus error - SDA stuck low */
|
|
DEB2("BUS ERROR - SDA Stuck low\n");
|
|
pca_reset(adap);
|
|
goto out;
|
|
case 0x90: /* Bus error - SCL stuck low */
|
|
DEB2("BUS ERROR - SCL Stuck low\n");
|
|
pca_reset(adap);
|
|
goto out;
|
|
case 0x00: /* Bus error during master or slave mode due to illegal START or STOP condition */
|
|
DEB2("BUS ERROR - Illegal START or STOP\n");
|
|
pca_reset(adap);
|
|
goto out;
|
|
default:
|
|
printk(KERN_ERR DRIVER ": unhandled SIO state 0x%02x\n", state);
|
|
break;
|
|
}
|
|
|
|
}
|
|
|
|
ret = curmsg;
|
|
out:
|
|
DEB1(KERN_CRIT "}}} transfered %d/%d messages. "
|
|
"status is %#04x. control is %#04x\n",
|
|
curmsg, num, pca_status(adap),
|
|
pca_get_con(adap));
|
|
return ret;
|
|
}
|
|
|
|
static u32 pca_func(struct i2c_adapter *adap)
|
|
{
|
|
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
|
|
}
|
|
|
|
static int pca_init(struct i2c_algo_pca_data *adap)
|
|
{
|
|
static int freqs[] = {330,288,217,146,88,59,44,36};
|
|
int own, clock;
|
|
|
|
own = pca_own(adap);
|
|
clock = pca_clock(adap);
|
|
DEB1(KERN_INFO DRIVER ": own address is %#04x\n", own);
|
|
DEB1(KERN_INFO DRIVER ": clock freqeuncy is %dkHz\n", freqs[clock]);
|
|
|
|
pca_outw(adap, I2C_PCA_ADR, own << 1);
|
|
|
|
pca_set_con(adap, I2C_PCA_CON_ENSIO | clock);
|
|
udelay(500); /* 500 µs for oscilator to stabilise */
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct i2c_algorithm pca_algo = {
|
|
.master_xfer = pca_xfer,
|
|
.functionality = pca_func,
|
|
};
|
|
|
|
/*
|
|
* registering functions to load algorithms at runtime
|
|
*/
|
|
int i2c_pca_add_bus(struct i2c_adapter *adap)
|
|
{
|
|
struct i2c_algo_pca_data *pca_adap = adap->algo_data;
|
|
int rval;
|
|
|
|
/* register new adapter to i2c module... */
|
|
adap->algo = &pca_algo;
|
|
|
|
adap->timeout = 100; /* default values, should */
|
|
adap->retries = 3; /* be replaced by defines */
|
|
|
|
if ((rval = pca_init(pca_adap)))
|
|
return rval;
|
|
|
|
rval = i2c_add_adapter(adap);
|
|
|
|
return rval;
|
|
}
|
|
EXPORT_SYMBOL(i2c_pca_add_bus);
|
|
|
|
MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>");
|
|
MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_param(i2c_debug, int, 0);
|