Re: [Patch V2 6/9] I2C: Add smbus word/block process call helper function

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 05/17/2014 06:21 PM, Wolfram Sang wrote:
On Mon, Apr 28, 2014 at 10:27:45PM +0800, Lan Tianyu wrote:
Add i2c_smbus_word/block_proc_call() helper function. These will be used
in the implementation of i2c ACPI address space handler.

Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx>
---
  drivers/i2c/i2c-core.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++
  include/linux/i2c.h    |  4 ++++
  2 files changed, 60 insertions(+)

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 3bf0048..638befd 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -2306,6 +2306,30 @@ s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command,
  EXPORT_SYMBOL(i2c_smbus_write_word_data);

  /**
+ * i2c_smbus_word_proc_call - SMBus "word proc call" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ * @value: 16-bit "word" being written
+ *
+ * This executes the SMBus "word proc all" protocol, returning negative errno
+ * else a 16-bit unsigned "word" received from the device.
+ */
+s32 i2c_smbus_word_proc_call(const struct i2c_client *client, u8 command,
+			      u16 value)
+{
+	union i2c_smbus_data data;
+	int status;
+
+	data.word = value;
+	status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+			      I2C_SMBUS_READ, command,
+			      I2C_SMBUS_PROC_CALL, &data);
+
+	return (status < 0) ? status : data.word;
+}
+EXPORT_SYMBOL(i2c_smbus_word_proc_call);
+
+/**

Same as smbus_quick function before, documentation updates are missing.
Also similar, we had such a function before which was removed due to no
users? It looks very much like the function here, so we should stick to
the old naming IMO. Is it the old one? Such information would be nice
since it affects reviewing.

Yes, there was an old function and commit c8110933 removed it. Sorry, I didn't that before. I will bring the old one back.


   * i2c_smbus_read_block_data - SMBus "block read" protocol
   * @client: Handle to slave device
   * @command: Byte interpreted by slave
@@ -2362,6 +2386,38 @@ s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command,
  }
  EXPORT_SYMBOL(i2c_smbus_write_block_data);

+/**
+ * i2c_smbus_block_proc_call - SMBus "block write" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ * @length: Size of data block; SMBus allows at most 32 bytes
+ * @values: Byte array which will be written.
+ *
+ * This executes the SMBus "block proc call" protocol, returning negative errno
+ * else the number of read bytes.
+ */
+s32 i2c_smbus_block_proc_call(const struct i2c_client *client, u8 command,
+			       u8 length, u8 *values)

Please rename to "i2c_smbus_block_process_call" as the old function was
named. Needs documentation updates.

+	if (length > I2C_SMBUS_BLOCK_MAX)
+		length = I2C_SMBUS_BLOCK_MAX;

I think we should return an error here.

Ok.


BTW what were your test scenarios for these functions and smbus quick?


From ACPI spec, Read/Write quick and Word/Block process call protocol will be used by Bios ACPI code. But so far, I don't find such machines. So these functions has not been tested.




--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux GPIO]     [Linux SPI]     [Linux Hardward Monitoring]     [LM Sensors]     [Linux USB Devel]     [Linux Media]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux