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authorAndrew Jeffery <andrew@aj.id.au>2017-11-20 15:12:05 +1030
committerGuenter Roeck <linux@roeck-us.net>2018-01-02 15:05:34 -0800
commit464df6fa3766784b85b00d56cd4d7c706aee5375 (patch)
tree25f345a09131db8ee92c63f9762fac13618d76e1 /drivers/hwmon
parent56ad86b4b16e4b7154300d71f8e93cca64b98e92 (diff)
hwmon: (pmbus) Add virtual page config bit
Some circumstances call for virtual pages, to expose multiple values packed into an extended PMBus register in a manner non-compliant with the PMBus standard. An example of this is the Maxim MAX31785 controller, which extends the READ_FAN_SPEED_1 PMBus register from two to four bytes to support tach readings for both rotors of a dual rotor fan. This extended register contains two word-sized values, one reporting the rate of the fastest rotor, the other the rate of the slowest. The concept of virtual pages aids this situation by mapping the page number onto the value to be selected from the vectored result. We should not try to set virtual pages on the device as such a page explicitly doesn't exist; add a flag so we can avoid doing so. Signed-off-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/pmbus/pmbus.h2
-rw-r--r--drivers/hwmon/pmbus/pmbus_core.c27
2 files changed, 20 insertions, 9 deletions
diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index b54d7604d3ef..d39d506aa63e 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -372,6 +372,8 @@ enum pmbus_sensor_classes {
#define PMBUS_HAVE_PWM12 BIT(20)
#define PMBUS_HAVE_PWM34 BIT(21)
+#define PMBUS_PAGE_VIRTUAL BIT(31)
+
enum pmbus_data_format { linear = 0, direct, vid };
enum vrm_version { vr11 = 0, vr12, vr13 };
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index fdd33857f117..99ab39f19bf4 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -162,18 +162,27 @@ EXPORT_SYMBOL_GPL(pmbus_clear_cache);
int pmbus_set_page(struct i2c_client *client, int page)
{
struct pmbus_data *data = i2c_get_clientdata(client);
- int rv = 0;
- int newpage;
+ int rv;
+
+ if (page < 0 || page == data->currpage)
+ return 0;
- if (page >= 0 && page != data->currpage) {
+ if (!(data->info->func[page] & PMBUS_PAGE_VIRTUAL)) {
rv = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
- newpage = i2c_smbus_read_byte_data(client, PMBUS_PAGE);
- if (newpage != page)
- rv = -EIO;
- else
- data->currpage = page;
+ if (rv < 0)
+ return rv;
+
+ rv = i2c_smbus_read_byte_data(client, PMBUS_PAGE);
+ if (rv < 0)
+ return rv;
+
+ if (rv != page)
+ return -EIO;
}
- return rv;
+
+ data->currpage = page;
+
+ return 0;
}
EXPORT_SYMBOL_GPL(pmbus_set_page);

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