diff options
| -rw-r--r-- | drivers/hwmon/pmbus/max34440.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/hwmon/pmbus/max34440.c b/drivers/hwmon/pmbus/max34440.c index 3d70c454efb5..56834d26f8ef 100644 --- a/drivers/hwmon/pmbus/max34440.c +++ b/drivers/hwmon/pmbus/max34440.c @@ -12,6 +12,7 @@ #include <linux/init.h> #include <linux/err.h> #include <linux/i2c.h> +#include <linux/delay.h> #include "pmbus.h" enum chips { @@ -24,6 +25,14 @@ enum chips { max34461, }; +/* + * Firmware is sometimes not ready if we try and read the + * data from the page immediately after setting. Maxim + * recommends 50us delay due to the chip failing to clock + * stretch long enough here. + */ +#define MAX34440_PAGE_CHANGE_DELAY 50 + #define MAX34440_MFR_VOUT_PEAK 0xd4 #define MAX34440_MFR_IOUT_PEAK 0xd5 #define MAX34440_MFR_TEMPERATURE_PEAK 0xd6 @@ -272,6 +281,7 @@ static int max34451_set_supported_funcs(struct i2c_client *client, for (page = 0; page < 16; page++) { rv = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page); + fsleep(MAX34440_PAGE_CHANGE_DELAY); if (rv < 0) return rv; @@ -395,6 +405,7 @@ static struct pmbus_driver_info max34440_info[] = { .read_byte_data = max34440_read_byte_data, .read_word_data = max34440_read_word_data, .write_word_data = max34440_write_word_data, + .page_change_delay = MAX34440_PAGE_CHANGE_DELAY, }, [max34441] = { .pages = 12, @@ -438,6 +449,7 @@ static struct pmbus_driver_info max34440_info[] = { .read_byte_data = max34440_read_byte_data, .read_word_data = max34440_read_word_data, .write_word_data = max34440_write_word_data, + .page_change_delay = MAX34440_PAGE_CHANGE_DELAY, }, [max34446] = { .pages = 7, @@ -475,6 +487,7 @@ static struct pmbus_driver_info max34440_info[] = { .read_byte_data = max34440_read_byte_data, .read_word_data = max34440_read_word_data, .write_word_data = max34440_write_word_data, + .page_change_delay = MAX34440_PAGE_CHANGE_DELAY, }, [max34451] = { .pages = 21, @@ -498,6 +511,7 @@ static struct pmbus_driver_info max34440_info[] = { .func[20] = PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP, .read_word_data = max34440_read_word_data, .write_word_data = max34440_write_word_data, + .page_change_delay = MAX34440_PAGE_CHANGE_DELAY, }, [max34460] = { .pages = 18, @@ -528,6 +542,7 @@ static struct pmbus_driver_info max34440_info[] = { .func[17] = PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP, .read_word_data = max34440_read_word_data, .write_word_data = max34440_write_word_data, + .page_change_delay = MAX34440_PAGE_CHANGE_DELAY, }, [max34461] = { .pages = 23, @@ -563,6 +578,7 @@ static struct pmbus_driver_info max34440_info[] = { .func[21] = PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP, .read_word_data = max34440_read_word_data, .write_word_data = max34440_write_word_data, + .page_change_delay = MAX34440_PAGE_CHANGE_DELAY, }, }; |