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path: root/drivers/i2c/algos/i2c-algo-pca.c
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Diffstat (limited to 'drivers/i2c/algos/i2c-algo-pca.c')
-rw-r--r--drivers/i2c/algos/i2c-algo-pca.c250
1 files changed, 207 insertions, 43 deletions
diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c
index d50b329a3c9..f68e5f8e23e 100644
--- a/drivers/i2c/algos/i2c-algo-pca.c
+++ b/drivers/i2c/algos/i2c-algo-pca.c
@@ -22,14 +22,18 @@
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/delay.h>
+#include <linux/jiffies.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-pca.h>
-#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)
+#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)
static int i2c_debug;
@@ -43,19 +47,27 @@ static int i2c_debug;
#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);
}
/*
@@ -63,14 +75,14 @@ static void pca_start(struct i2c_algo_pca_data *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);
}
/*
@@ -96,7 +108,7 @@ static void pca_stop(struct i2c_algo_pca_data *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);
@@ -113,7 +125,7 @@ static void pca_address(struct i2c_algo_pca_data *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);
}
/*
@@ -121,7 +133,7 @@ static void pca_address(struct i2c_algo_pca_data *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);
@@ -131,7 +143,7 @@ static void pca_tx_byte(struct i2c_algo_pca_data *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);
}
/*
@@ -151,7 +163,7 @@ static void pca_rx_byte(struct i2c_algo_pca_data *adap,
*
* 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);
@@ -162,7 +174,7 @@ static void pca_rx_ack(struct i2c_algo_pca_data *adap,
sta |= I2C_PCA_CON_AA;
pca_set_con(adap, sta);
- pca_wait(adap);
+ return pca_wait(adap);
}
static int pca_xfer(struct i2c_adapter *i2c_adap,
@@ -175,14 +187,17 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
int numbytes = 0;
int state;
int ret;
- int timeout = i2c_adap->timeout;
-
- 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 -EAGAIN;
+ int completed = 1;
+ unsigned long timeout = jiffies + i2c_adap->timeout;
+
+ while (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);
@@ -218,18 +233,19 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
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;
}
@@ -237,7 +253,7 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
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 */
@@ -246,21 +262,22 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
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 */
@@ -283,7 +300,7 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
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",
@@ -309,11 +326,13 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
break;
}
+ if (!completed)
+ goto out;
}
ret = curmsg;
out:
- DEB1(KERN_CRIT "}}} transfered %d/%d messages. "
+ DEB1("}}} transfered %d/%d messages. "
"status is %#04x. control is %#04x\n",
curmsg, num, pca_status(adap),
pca_get_con(adap));
@@ -330,26 +349,171 @@ static const struct i2c_algorithm pca_algo = {
.functionality = pca_func,
};
-static int pca_init(struct i2c_adapter *adap)
+static unsigned int pca_probe_chip(struct i2c_adapter *adap)
{
- static int freqs[] = {330,288,217,146,88,59,44,36};
- int clock;
struct i2c_algo_pca_data *pca_data = adap->algo_data;
-
- if (pca_data->i2c_clock > 7) {
- printk(KERN_WARNING "%s: Invalid I2C clock speed selected. Trying default.\n",
- adap->name);
- pca_data->i2c_clock = I2C_PCA_CON_59kHz;
+ /* 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;
}
+}
+
+static int pca_init(struct i2c_adapter *adap)
+{
+ struct i2c_algo_pca_data *pca_data = adap->algo_data;
adap->algo = &pca_algo;
- pca_reset(pca_data);
+ if (pca_probe_chip(adap) == I2C_PCA_CHIP_9564) {
+ static int freqs[] = {330, 288, 217, 146, 88, 59, 44, 36};
+ int clock;
+
+ 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);
+ }
+
+ 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;
+ }
+
+ 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;
+ }
- clock = pca_clock(pca_data);
- DEB1(KERN_INFO "%s: Clock frequency is %dkHz\n", adap->name, freqs[clock]);
+ /* 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 */
+ }
+
+ /* 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_set_con(pca_data, I2C_PCA_CON_ENSIO | clock);
+ pca_reset(pca_data);
+
+ printk(KERN_INFO
+ "%s: Clock frequency is %dHz\n", adap->name, clock * 100);
+
+ 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);
+
+ pca_set_con(pca_data, I2C_PCA_CON_ENSIO);
+ }
udelay(500); /* 500 us for oscilator to stabilise */
return 0;
@@ -384,7 +548,7 @@ 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 algorithm");
+MODULE_DESCRIPTION("I2C-Bus PCA9564/PCA9665 algorithm");
MODULE_LICENSE("GPL");
module_param(i2c_debug, int, 0);
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-16 01:43:20 +0000