/*
- * i2c-algo-pca.c i2c driver algorithms for PCA9564 adapters
+ * i2c-algo-pca.c i2c driver algorithms for PCA9564 adapters
* Copyright (C) 2004 Arcom Control Systems
+ * Copyright (C) 2008 Pengutronix
*
* 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
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/delay.h>
-#include <linux/slab.h>
+#include <linux/jiffies.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(KERN_DEBUG fmt, ## args); } while (0)
+#define DEB2(fmt, args...) do { if (i2c_debug >= 2) \
+ printk(KERN_DEBUG fmt, ## args); } while (0)
+#define DEB3(fmt, args...) do { if (i2c_debug >= 3) \
+ printk(KERN_DEBUG fmt, ## args); } while (0)
-#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;
-static int i2c_debug=0;
-
-#define pca_outw(adap, reg, val) adap->write_byte(adap, reg, val)
-#define pca_inw(adap, reg) adap->read_byte(adap, reg)
+#define pca_outw(adap, reg, val) adap->write_byte(adap->data, reg, val)
+#define pca_inw(adap, reg) adap->read_byte(adap->data, 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_clock(adap) adap->i2c_clock
#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)
+#define pca_wait(adap) adap->wait_for_completion(adap->data)
+#define pca_reset(adap) adap->reset_chip(adap->data)
+
+static void pca9665_reset(void *pd)
+{
+ struct i2c_algo_pca_data *adap = pd;
+ pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_IPRESET);
+ pca_outw(adap, I2C_PCA_IND, 0xA5);
+ pca_outw(adap, I2C_PCA_IND, 0x5A);
+}
/*
* 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)
+static int 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);
+ return pca_wait(adap);
}
/*
*
* return after the repeated start condition has occurred
*/
-static void pca_repeated_start(struct i2c_algo_pca_data *adap)
+static int 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);
+ return pca_wait(adap);
}
/*
*
* returns after the address has been sent
*/
-static void pca_address(struct i2c_algo_pca_data *adap,
+static int pca_address(struct i2c_algo_pca_data *adap,
struct i2c_msg *msg)
{
int sta = pca_get_con(adap);
addr = ( (0x7f & msg->addr) << 1 );
if (msg->flags & I2C_M_RD )
addr |= 1;
- DEB2("=== SLAVE ADDRESS %#04x+%c=%#04x\n",
+ 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);
+ return pca_wait(adap);
}
/*
*
* Returns after the byte has been transmitted
*/
-static void pca_tx_byte(struct i2c_algo_pca_data *adap,
+static int pca_tx_byte(struct i2c_algo_pca_data *adap,
__u8 b)
{
int sta = pca_get_con(adap);
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
pca_set_con(adap, sta);
- pca_wait(adap);
+ return pca_wait(adap);
}
/*
*
* returns immediately.
*/
-static void pca_rx_byte(struct i2c_algo_pca_data *adap,
+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,
+static int pca_rx_ack(struct i2c_algo_pca_data *adap,
int ack)
{
int sta = pca_get_con(adap);
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");
+ return pca_wait(adap);
}
static int pca_xfer(struct i2c_adapter *i2c_adap,
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;
+ int completed = 1;
+ unsigned long timeout = jiffies + i2c_adap->timeout;
+
+ while ((state = pca_status(adap)) != 0xf8) {
+ if (time_before(jiffies, timeout)) {
+ msleep(10);
+ } else {
+ dev_dbg(&i2c_adap->dev, "bus is not idle. status is "
+ "%#04x\n", state);
+ return -EAGAIN;
+ }
}
DEB1("{{{ XFER %d messages\n", num);
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",
+ 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",
+ 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++)
switch (state) {
case 0xf8: /* On reset or stop the bus is idle */
- pca_start(adap);
+ completed = 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);
+ completed = 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]);
+ completed = pca_tx_byte(adap,
+ msg->buf[numbytes]);
numbytes++;
break;
}
if (curmsg == num)
pca_stop(adap);
else
- pca_repeated_start(adap);
+ completed = pca_repeated_start(adap);
break;
case 0x20: /* SLA+W has been transmitted; NOT ACK has been received */
goto out;
case 0x40: /* SLA+R has been transmitted; ACK has been received */
- pca_rx_ack(adap, msg->len > 1);
+ completed = 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);
+ completed = pca_rx_ack(adap,
+ numbytes < msg->len - 1);
break;
}
curmsg++; numbytes = 0;
if (curmsg == num)
pca_stop(adap);
else
- pca_repeated_start(adap);
+ completed = pca_repeated_start(adap);
break;
case 0x48: /* SLA+R has been transmitted; NOT ACK has been received */
case 0x30: /* Data byte in I2CDAT has been transmitted; NOT ACK has been received */
DEB2("NOT ACK received after data byte\n");
+ pca_stop(adap);
goto out;
case 0x38: /* Arbitration lost during SLA+W, SLA+R or data bytes */
DEB2("Arbitration lost\n");
+ /*
+ * The PCA9564 data sheet (2006-09-01) says "A
+ * START condition will be transmitted when the
+ * bus becomes free (STOP or SCL and SDA high)"
+ * when the STA bit is set (p. 11).
+ *
+ * In case this won't work, try pca_reset()
+ * instead.
+ */
+ pca_start(adap);
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);
if (curmsg == num)
pca_stop(adap);
else
- pca_repeated_start(adap);
+ completed = pca_repeated_start(adap);
} else {
DEB2("NOT ACK sent after data byte received. "
"Not final byte. numbytes %d. len %d\n",
pca_reset(adap);
goto out;
default:
- printk(KERN_ERR DRIVER ": unhandled SIO state 0x%02x\n", state);
+ dev_err(&i2c_adap->dev, "unhandled SIO state 0x%02x\n", state);
break;
}
-
+
+ if (!completed)
+ goto out;
}
ret = curmsg;
out:
- DEB1(KERN_CRIT "}}} transfered %d/%d messages. "
- "status is %#04x. control is %#04x\n",
+ DEB1("}}} transfered %d/%d messages. "
+ "status is %#04x. control is %#04x\n",
curmsg, num, pca_status(adap),
pca_get_con(adap));
return ret;
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
-static int pca_init(struct i2c_algo_pca_data *adap)
+static const struct i2c_algorithm pca_algo = {
+ .master_xfer = pca_xfer,
+ .functionality = pca_func,
+};
+
+static unsigned int pca_probe_chip(struct i2c_adapter *adap)
{
- static int freqs[] = {330,288,217,146,88,59,44,36};
- int own, clock;
+ struct i2c_algo_pca_data *pca_data = adap->algo_data;
+ /* The trick here is to check if there is an indirect register
+ * available. If there is one, we will read the value we first
+ * wrote on I2C_PCA_IADR. Otherwise, we will read the last value
+ * we wrote on I2C_PCA_ADR
+ */
+ pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IADR);
+ pca_outw(pca_data, I2C_PCA_IND, 0xAA);
+ pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ITO);
+ pca_outw(pca_data, I2C_PCA_IND, 0x00);
+ pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IADR);
+ if (pca_inw(pca_data, I2C_PCA_IND) == 0xAA) {
+ printk(KERN_INFO "%s: PCA9665 detected.\n", adap->name);
+ return I2C_PCA_CHIP_9665;
+ } else {
+ printk(KERN_INFO "%s: PCA9564 detected.\n", adap->name);
+ return I2C_PCA_CHIP_9564;
+ }
+}
- 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]);
+static int pca_init(struct i2c_adapter *adap)
+{
+ struct i2c_algo_pca_data *pca_data = adap->algo_data;
- pca_outw(adap, I2C_PCA_ADR, own << 1);
+ adap->algo = &pca_algo;
- pca_set_con(adap, I2C_PCA_CON_ENSIO | clock);
- udelay(500); /* 500 µs for oscilator to stabilise */
+ if (pca_probe_chip(adap) == I2C_PCA_CHIP_9564) {
+ static int freqs[] = {330, 288, 217, 146, 88, 59, 44, 36};
+ int clock;
- return 0;
-}
+ if (pca_data->i2c_clock > 7) {
+ switch (pca_data->i2c_clock) {
+ case 330000:
+ pca_data->i2c_clock = I2C_PCA_CON_330kHz;
+ break;
+ case 288000:
+ pca_data->i2c_clock = I2C_PCA_CON_288kHz;
+ break;
+ case 217000:
+ pca_data->i2c_clock = I2C_PCA_CON_217kHz;
+ break;
+ case 146000:
+ pca_data->i2c_clock = I2C_PCA_CON_146kHz;
+ break;
+ case 88000:
+ pca_data->i2c_clock = I2C_PCA_CON_88kHz;
+ break;
+ case 59000:
+ pca_data->i2c_clock = I2C_PCA_CON_59kHz;
+ break;
+ case 44000:
+ pca_data->i2c_clock = I2C_PCA_CON_44kHz;
+ break;
+ case 36000:
+ pca_data->i2c_clock = I2C_PCA_CON_36kHz;
+ break;
+ default:
+ printk(KERN_WARNING
+ "%s: Invalid I2C clock speed selected."
+ " Using default 59kHz.\n", adap->name);
+ pca_data->i2c_clock = I2C_PCA_CON_59kHz;
+ }
+ } else {
+ printk(KERN_WARNING "%s: "
+ "Choosing the clock frequency based on "
+ "index is deprecated."
+ " Use the nominal frequency.\n", adap->name);
+ }
-static struct i2c_algorithm pca_algo = {
- .id = I2C_ALGO_PCA,
- .master_xfer = pca_xfer,
- .functionality = pca_func,
-};
+ pca_reset(pca_data);
+
+ clock = pca_clock(pca_data);
+ printk(KERN_INFO "%s: Clock frequency is %dkHz\n",
+ adap->name, freqs[clock]);
+
+ pca_set_con(pca_data, I2C_PCA_CON_ENSIO | clock);
+ } else {
+ int clock;
+ int mode;
+ int tlow, thi;
+ /* Values can be found on PCA9665 datasheet section 7.3.2.6 */
+ int min_tlow, min_thi;
+ /* These values are the maximum raise and fall values allowed
+ * by the I2C operation mode (Standard, Fast or Fast+)
+ * They are used (added) below to calculate the clock dividers
+ * of PCA9665. Note that they are slightly different of the
+ * real maximum, to allow the change on mode exactly on the
+ * maximum clock rate for each mode
+ */
+ int raise_fall_time;
+
+ struct i2c_algo_pca_data *pca_data = adap->algo_data;
+
+ /* Ignore the reset function from the module,
+ * we can use the parallel bus reset
+ */
+ pca_data->reset_chip = pca9665_reset;
+
+ if (pca_data->i2c_clock > 1265800) {
+ printk(KERN_WARNING "%s: I2C clock speed too high."
+ " Using 1265.8kHz.\n", adap->name);
+ pca_data->i2c_clock = 1265800;
+ }
-/*
- * 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;
+ if (pca_data->i2c_clock < 60300) {
+ printk(KERN_WARNING "%s: I2C clock speed too low."
+ " Using 60.3kHz.\n", adap->name);
+ pca_data->i2c_clock = 60300;
+ }
- /* register new adapter to i2c module... */
+ /* To avoid integer overflow, use clock/100 for calculations */
+ clock = pca_clock(pca_data) / 100;
+
+ if (pca_data->i2c_clock > 10000) {
+ mode = I2C_PCA_MODE_TURBO;
+ min_tlow = 14;
+ min_thi = 5;
+ raise_fall_time = 22; /* Raise 11e-8s, Fall 11e-8s */
+ } else if (pca_data->i2c_clock > 4000) {
+ mode = I2C_PCA_MODE_FASTP;
+ min_tlow = 17;
+ min_thi = 9;
+ raise_fall_time = 22; /* Raise 11e-8s, Fall 11e-8s */
+ } else if (pca_data->i2c_clock > 1000) {
+ mode = I2C_PCA_MODE_FAST;
+ min_tlow = 44;
+ min_thi = 20;
+ raise_fall_time = 58; /* Raise 29e-8s, Fall 29e-8s */
+ } else {
+ mode = I2C_PCA_MODE_STD;
+ min_tlow = 157;
+ min_thi = 134;
+ raise_fall_time = 127; /* Raise 29e-8s, Fall 98e-8s */
+ }
- adap->id |= pca_algo.id;
- adap->algo = &pca_algo;
+ /* The minimum clock that respects the thi/tlow = 134/157 is
+ * 64800 Hz. Below that, we have to fix the tlow to 255 and
+ * calculate the thi factor.
+ */
+ if (clock < 648) {
+ tlow = 255;
+ thi = 1000000 - clock * raise_fall_time;
+ thi /= (I2C_PCA_OSC_PER * clock) - tlow;
+ } else {
+ tlow = (1000000 - clock * raise_fall_time) * min_tlow;
+ tlow /= I2C_PCA_OSC_PER * clock * (min_thi + min_tlow);
+ thi = tlow * min_thi / min_tlow;
+ }
+
+ pca_reset(pca_data);
- adap->timeout = 100; /* default values, should */
- adap->retries = 3; /* be replaced by defines */
+ printk(KERN_INFO
+ "%s: Clock frequency is %dHz\n", adap->name, clock * 100);
- rval = pca_init(pca_adap);
+ pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IMODE);
+ pca_outw(pca_data, I2C_PCA_IND, mode);
+ pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ISCLL);
+ pca_outw(pca_data, I2C_PCA_IND, tlow);
+ pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ISCLH);
+ pca_outw(pca_data, I2C_PCA_IND, thi);
- if (!rval)
- i2c_add_adapter(adap);
+ pca_set_con(pca_data, I2C_PCA_CON_ENSIO);
+ }
+ udelay(500); /* 500 us for oscilator to stabilise */
- return rval;
+ return 0;
}
-int i2c_pca_del_bus(struct i2c_adapter *adap)
+/*
+ * registering functions to load algorithms at runtime
+ */
+int i2c_pca_add_bus(struct i2c_adapter *adap)
{
- return i2c_del_adapter(adap);
-}
+ int rval;
+ rval = pca_init(adap);
+ if (rval)
+ return rval;
+
+ return i2c_add_adapter(adap);
+}
EXPORT_SYMBOL(i2c_pca_add_bus);
-EXPORT_SYMBOL(i2c_pca_del_bus);
-MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>");
-MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm");
+int i2c_pca_add_numbered_bus(struct i2c_adapter *adap)
+{
+ int rval;
+
+ rval = pca_init(adap);
+ if (rval)
+ return rval;
+
+ return i2c_add_numbered_adapter(adap);
+}
+EXPORT_SYMBOL(i2c_pca_add_numbered_bus);
+
+MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>, "
+ "Wolfram Sang <w.sang@pengutronix.de>");
+MODULE_DESCRIPTION("I2C-Bus PCA9564/PCA9665 algorithm");
MODULE_LICENSE("GPL");
module_param(i2c_debug, int, 0);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff