Re: [PATCH v4 2/4] pmbus: core: add helpers for byte write and read modify write

From: Guenter Roeck
Date: Thu Oct 02 2014 - 00:06:09 EST


On 10/01/2014 12:05 PM, atull@xxxxxxxxxxxxxxxxxxxxx wrote:
From: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx>

Add two helper functions:
* pmbus_write_byte_data = paged byte write
* pmbus_update_byte_data = paged byte read/modify/write

Signed-off-by: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/hwmon/pmbus/pmbus_core.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)

diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 291d11f..d6c3701 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -253,6 +253,37 @@ int pmbus_read_byte_data(struct i2c_client *client, int page, u8 reg)
}
EXPORT_SYMBOL_GPL(pmbus_read_byte_data);

+int pmbus_write_byte_data(struct i2c_client *client, int page, u8 reg, u8 value)
+{
+ int rv;
+
+ rv = pmbus_set_page(client, page);
+ if (rv < 0)
+ return rv;
+
+ return i2c_smbus_write_byte_data(client, reg, value);
+}
+EXPORT_SYMBOL_GPL(pmbus_write_byte_data);
+
+int pmbus_update_byte_data(struct i2c_client *client, int page, u8 reg,
+ u8 mask, u8 value)
+{
+ unsigned int tmp;
+ int rv;
+
+ rv = pmbus_read_byte_data(client, page, reg);
+ if (rv < 0)
+ return rv;
+
+ tmp = (rv & ~mask) | (value & mask);
+
+ if (tmp != rv)
+ rv = pmbus_write_byte_data(client, page, reg, tmp);
+
+ return rv;
+}
+EXPORT_SYMBOL_GPL(pmbus_update_byte_data);
+
/*
* _pmbus_read_byte_data() is similar to pmbus_read_byte_data(), but checks if
* a device specific mapping function exists and calls it if necessary.


Results in:

drivers/hwmon/pmbus/pmbus_core.c:259:5: warning: symbol 'pmbus_write_byte_data' was not declared. Should it be static?
drivers/hwmon/pmbus/pmbus_core.c:271:5: warning: symbol 'pmbus_update_byte_data' was not declared. Should it be static?
drivers/hwmon/pmbus/pmbus_core.c:259:5: warning: no previous prototype for 'pmbus_write_byte_data' [-Wmissing-prototypes]
drivers/hwmon/pmbus/pmbus_core.c:271:5: warning: no previous prototype for 'pmbus_update_byte_data' [-Wmissing-prototypes]

No need to resubmit. I added a patch to un-export the functions
and merged patch 2 and 3 together in order to avoid a warning
after patch 2. We can always export the new helper functions
later if needed.

Guenter

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