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-rw-r--r--drivers/hwmon/pmbus/pmbus.h10
-rw-r--r--drivers/hwmon/pmbus/pmbus_core.c92
2 files changed, 96 insertions, 6 deletions
diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index fb442fae7b3e..5d5dc774187b 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -466,6 +466,16 @@ struct pmbus_driver_info {
/* custom attributes */
const struct attribute_group **groups;
+
+ /*
+ * Some chips need a little delay between SMBus communication. When
+ * set, the generic PMBus helper functions will wait if necessary
+ * to meet this requirement. The access delay is honored after
+ * every SMBus operation. The write delay is only honored after
+ * SMBus write operations.
+ */
+ int access_delay; /* in microseconds */
+ int write_delay; /* in microseconds */
};
/* Regulator ops */
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index cb4c65a7f288..0ea6fe7eb17c 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -7,6 +7,7 @@
*/
#include <linux/debugfs.h>
+#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/math64.h>
#include <linux/module.h>
@@ -108,6 +109,8 @@ struct pmbus_data {
int vout_low[PMBUS_PAGES]; /* voltage low margin */
int vout_high[PMBUS_PAGES]; /* voltage high margin */
+ ktime_t write_time; /* Last SMBUS write timestamp */
+ ktime_t access_time; /* Last SMBUS access timestamp */
};
struct pmbus_debugfs_entry {
@@ -158,6 +161,39 @@ void pmbus_set_update(struct i2c_client *client, u8 reg, bool update)
}
EXPORT_SYMBOL_NS_GPL(pmbus_set_update, PMBUS);
+/* Some chips need a delay between accesses. */
+static void pmbus_wait(struct i2c_client *client)
+{
+ struct pmbus_data *data = i2c_get_clientdata(client);
+ const struct pmbus_driver_info *info = data->info;
+ s64 delta;
+
+ if (info->access_delay) {
+ delta = ktime_us_delta(ktime_get(), data->access_time);
+
+ if (delta < info->access_delay)
+ fsleep(info->access_delay - delta);
+ } else if (info->write_delay) {
+ delta = ktime_us_delta(ktime_get(), data->write_time);
+
+ if (delta < info->write_delay)
+ fsleep(info->write_delay - delta);
+ }
+}
+
+/* Sets the last accessed timestamp for pmbus_wait */
+static void pmbus_update_ts(struct i2c_client *client, bool write_op)
+{
+ struct pmbus_data *data = i2c_get_clientdata(client);
+ const struct pmbus_driver_info *info = data->info;
+
+ if (info->access_delay) {
+ data->access_time = ktime_get();
+ } else if (info->write_delay && write_op) {
+ data->write_time = ktime_get();
+ }
+}
+
int pmbus_set_page(struct i2c_client *client, int page, int phase)
{
struct pmbus_data *data = i2c_get_clientdata(client);
@@ -168,11 +204,15 @@ int pmbus_set_page(struct i2c_client *client, int page, int phase)
if (!(data->info->func[page] & PMBUS_PAGE_VIRTUAL) &&
data->info->pages > 1 && page != data->currpage) {
+ pmbus_wait(client);
rv = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
+ pmbus_update_ts(client, true);
if (rv < 0)
return rv;
+ pmbus_wait(client);
rv = i2c_smbus_read_byte_data(client, PMBUS_PAGE);
+ pmbus_update_ts(client, false);
if (rv < 0)
return rv;
@@ -183,8 +223,10 @@ int pmbus_set_page(struct i2c_client *client, int page, int phase)
if (data->info->phases[page] && data->currphase != phase &&
!(data->info->func[page] & PMBUS_PHASE_VIRTUAL)) {
+ pmbus_wait(client);
rv = i2c_smbus_write_byte_data(client, PMBUS_PHASE,
phase);
+ pmbus_update_ts(client, true);
if (rv)
return rv;
}
@@ -202,7 +244,11 @@ int pmbus_write_byte(struct i2c_client *client, int page, u8 value)
if (rv < 0)
return rv;
- return i2c_smbus_write_byte(client, value);
+ pmbus_wait(client);
+ rv = i2c_smbus_write_byte(client, value);
+ pmbus_update_ts(client, true);
+
+ return rv;
}
EXPORT_SYMBOL_NS_GPL(pmbus_write_byte, PMBUS);
@@ -233,7 +279,11 @@ int pmbus_write_word_data(struct i2c_client *client, int page, u8 reg,
if (rv < 0)
return rv;
- return i2c_smbus_write_word_data(client, reg, word);
+ pmbus_wait(client);
+ rv = i2c_smbus_write_word_data(client, reg, word);
+ pmbus_update_ts(client, true);
+
+ return rv;
}
EXPORT_SYMBOL_NS_GPL(pmbus_write_word_data, PMBUS);
@@ -351,7 +401,11 @@ int pmbus_read_word_data(struct i2c_client *client, int page, int phase, u8 reg)
if (rv < 0)
return rv;
- return i2c_smbus_read_word_data(client, reg);
+ pmbus_wait(client);
+ rv = i2c_smbus_read_word_data(client, reg);
+ pmbus_update_ts(client, false);
+
+ return rv;
}
EXPORT_SYMBOL_NS_GPL(pmbus_read_word_data, PMBUS);
@@ -410,7 +464,11 @@ int pmbus_read_byte_data(struct i2c_client *client, int page, u8 reg)
if (rv < 0)
return rv;
- return i2c_smbus_read_byte_data(client, reg);
+ pmbus_wait(client);
+ rv = i2c_smbus_read_byte_data(client, reg);
+ pmbus_update_ts(client, false);
+
+ return rv;
}
EXPORT_SYMBOL_NS_GPL(pmbus_read_byte_data, PMBUS);
@@ -422,7 +480,11 @@ int pmbus_write_byte_data(struct i2c_client *client, int page, u8 reg, u8 value)
if (rv < 0)
return rv;
- return i2c_smbus_write_byte_data(client, reg, value);
+ pmbus_wait(client);
+ rv = i2c_smbus_write_byte_data(client, reg, value);
+ pmbus_update_ts(client, true);
+
+ return rv;
}
EXPORT_SYMBOL_NS_GPL(pmbus_write_byte_data, PMBUS);
@@ -454,7 +516,11 @@ static int pmbus_read_block_data(struct i2c_client *client, int page, u8 reg,
if (rv < 0)
return rv;
- return i2c_smbus_read_block_data(client, reg, data_buf);
+ pmbus_wait(client);
+ rv = i2c_smbus_read_block_data(client, reg, data_buf);
+ pmbus_update_ts(client, false);
+
+ return rv;
}
static struct pmbus_sensor *pmbus_find_sensor(struct pmbus_data *data, int page,
@@ -2450,9 +2516,11 @@ static int pmbus_read_coefficients(struct i2c_client *client,
data.block[1] = attr->reg;
data.block[2] = 0x01;
+ pmbus_wait(client);
rv = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
I2C_SMBUS_WRITE, PMBUS_COEFFICIENTS,
I2C_SMBUS_BLOCK_PROC_CALL, &data);
+ pmbus_update_ts(client, true);
if (rv < 0)
return rv;
@@ -2604,7 +2672,10 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
/* Enable PEC if the controller and bus supports it */
if (!(data->flags & PMBUS_NO_CAPABILITY)) {
+ pmbus_wait(client);
ret = i2c_smbus_read_byte_data(client, PMBUS_CAPABILITY);
+ pmbus_update_ts(client, false);
+
if (ret >= 0 && (ret & PB_CAPABILITY_ERROR_CHECK)) {
if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_PEC))
client->flags |= I2C_CLIENT_PEC;
@@ -2617,10 +2688,16 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
* Bail out if both registers are not supported.
*/
data->read_status = pmbus_read_status_word;
+ pmbus_wait(client);
ret = i2c_smbus_read_word_data(client, PMBUS_STATUS_WORD);
+ pmbus_update_ts(client, false);
+
if (ret < 0 || ret == 0xffff) {
data->read_status = pmbus_read_status_byte;
+ pmbus_wait(client);
ret = i2c_smbus_read_byte_data(client, PMBUS_STATUS_BYTE);
+ pmbus_update_ts(client, false);
+
if (ret < 0 || ret == 0xff) {
dev_err(dev, "PMBus status register not found\n");
return -ENODEV;
@@ -2635,7 +2712,10 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
* limit registers need to be disabled.
*/
if (!(data->flags & PMBUS_NO_WRITE_PROTECT)) {
+ pmbus_wait(client);
ret = i2c_smbus_read_byte_data(client, PMBUS_WRITE_PROTECT);
+ pmbus_update_ts(client, false);
+
if (ret > 0 && (ret & PB_WP_ANY))
data->flags |= PMBUS_WRITE_PROTECTED | PMBUS_SKIP_STATUS_CHECK;
}
generated by cgit (git 2.34.1) at 2025-05-28 11:58:04 +0000