From: "Edward A. James" <eaja...@us.ibm.com>
Pmbus core always reads byte data from the status register, even if
configured to use STATUS_WORD. Use a function pointer so we always do
either byte or word access depending on which register we're trying to
access. Also switch to use STATUS_WORD by default.
Signed-off-by: Edward A. James <eaja...@us.ibm.com>
---
drivers/hwmon/pmbus/pmbus_core.c | 69 +++++++++++++++++++++++++++++++---------
1 file changed, 54 insertions(+), 15 deletions(-)
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index f1eff6b..8511aba 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -113,7 +113,8 @@ struct pmbus_data {
* so we keep them all together.
*/
u8 status[PB_NUM_STATUS_REG];
- u8 status_register;
+
+ int (*read_status)(struct i2c_client *client, int page);
u8 currpage;
};
@@ -324,7 +325,7 @@ static int pmbus_check_status_cml(struct i2c_client *client)
struct pmbus_data *data = i2c_get_clientdata(client);
int status, status2;
- status = _pmbus_read_byte_data(client, -1, data->status_register);
+ status = data->read_status(client, -1);
if (status < 0 || (status & PB_STATUS_CML)) {
status2 = _pmbus_read_byte_data(client, -1, PMBUS_STATUS_CML);
if (status2 < 0 || (status2 & PB_CML_FAULT_INVALID_COMMAND))
@@ -348,6 +349,36 @@ static bool pmbus_check_register(struct i2c_client *client,
return rv >= 0;
}
+/* Check specified page status register accessibility. Need a separate
+ * function rather than the two above so we can use the correct status
+ * register, and we can optimize out the second status register read.
+ */
+static bool pmbus_check_status_register(struct i2c_client *client, int page)
+{
+ int status, rc = 0;
+ struct pmbus_data *data = i2c_get_clientdata(client);
+
+ status = data->read_status(client, page);
+ if (status < 0)
+ goto out;
+
+ if (!(data->flags & PMBUS_SKIP_STATUS_CHECK)) {
+ if (status & PB_STATUS_CML) {
+ status = _pmbus_read_byte_data(client, -1,
+ PMBUS_STATUS_CML);
+ if (status < 0 ||
+ (status & PB_CML_FAULT_INVALID_COMMAND))
+ goto out;
+ }
+ }
+
+ rc = 1;
+
+out:
+ pmbus_clear_fault_page(client, -1);
+ return rc;
+}
+
bool pmbus_check_byte_register(struct i2c_client *client, int page, int reg)
{
return pmbus_check_register(client, _pmbus_read_byte_data, page, reg);
@@ -393,9 +424,8 @@ static struct pmbus_data *pmbus_update_device(struct device
*dev)
int i, j;
for (i = 0; i < info->pages; i++) {
- data->status[PB_STATUS_BASE + i]
- = _pmbus_read_byte_data(client, i,
- data->status_register);
+ data->status[PB_STATUS_BASE + i] =
+ data->read_status(client, i);
for (j = 0; j < ARRAY_SIZE(pmbus_status); j++) {
struct _pmbus_status *s = &pmbus_status[j];
@@ -1051,8 +1081,7 @@ static int pmbus_add_sensor_attrs_one(struct i2c_client
*client,
* the generic status register for this page is accessible.
*/
if (!ret && attr->gbit &&
- pmbus_check_byte_register(client, page,
- data->status_register)) {
+ pmbus_check_status_register(client, page)) {
ret = pmbus_add_boolean(data, name, "alarm", index,
NULL, NULL,
PB_STATUS_BASE + page,
@@ -1729,6 +1758,16 @@ static int pmbus_identify_common(struct i2c_client
*client,
return 0;
}
+static int pmbus_read_status_word(struct i2c_client *client, int page)
+{
+ return _pmbus_read_word_data(client, page, PMBUS_STATUS_WORD);
+}
+
+static int pmbus_read_status_byte(struct i2c_client *client, int page)
+{
+ return _pmbus_read_byte_data(client, page, PMBUS_STATUS_BYTE);
+}
+
static int pmbus_init_common(struct i2c_client *client, struct pmbus_data
*data,
struct pmbus_driver_info *info)
{
@@ -1736,16 +1775,16 @@ static int pmbus_init_common(struct i2c_client *client,
struct pmbus_data *data,
int page, ret;
/*
- * Some PMBus chips don't support PMBUS_STATUS_BYTE, so try
- * to use PMBUS_STATUS_WORD instead if that is the case.
+ * Some PMBus chips don't support PMBUS_STATUS_WORD, so try
+ * to use PMBUS_STATUS_BYTE instead if that is the case.
* Bail out if both registers are not supported.
*/
- data->status_register = PMBUS_STATUS_BYTE;
- ret = i2c_smbus_read_byte_data(client, PMBUS_STATUS_BYTE);
- if (ret < 0 || ret == 0xff) {
- data->status_register = PMBUS_STATUS_WORD;
- ret = i2c_smbus_read_word_data(client, PMBUS_STATUS_WORD);
- if (ret < 0 || ret == 0xffff) {
+ data->read_status = pmbus_read_status_word;
+ ret = i2c_smbus_read_word_data(client, PMBUS_STATUS_WORD);
+ if (ret < 0 || ret == 0xffff) {
+ data->read_status = pmbus_read_status_byte;
+ ret = i2c_smbus_read_byte_data(client, PMBUS_STATUS_BYTE);
+ if (ret < 0 || ret == 0xff) {
dev_err(dev, "PMBus status register not found\n");
return -ENODEV;
}
--
1.8.3.1
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