[PATCH 05/13] eeprom: ee1004: Improve check for SMBUS features

From: Heiner Kallweit
Date: Mon May 24 2021 - 16:18:55 EST


We have to read 512 bytes only, therefore read performance isn't really
a concern. Don't bother the user if i2c block read isn't supported.

For i2c_smbus_read_i2c_block_data_or_emulated() to work it's sufficient
if I2C_FUNC_SMBUS_READ_I2C_BLOCK or I2C_FUNC_SMBUS_READ_BYTE_DATA is
supported. Therefore remove the check for I2C_FUNC_SMBUS_READ_WORD_DATA.

In addition check for I2C_FUNC_SMBUS_WRITE_BYTE (included in
I2C_FUNC_SMBUS_BYTE) which is needed for setting the page.

Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
---
drivers/misc/eeprom/ee1004.c | 22 ++++------------------
1 file changed, 4 insertions(+), 18 deletions(-)

diff --git a/drivers/misc/eeprom/ee1004.c b/drivers/misc/eeprom/ee1004.c
index b991ab250..0d497e0e4 100644
--- a/drivers/misc/eeprom/ee1004.c
+++ b/drivers/misc/eeprom/ee1004.c
@@ -167,23 +167,13 @@ static int ee1004_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int err, cnr = 0;
- const char *slow = NULL;

/* Make sure we can operate on this adapter */
if (!i2c_check_functionality(client->adapter,
- I2C_FUNC_SMBUS_READ_BYTE |
- I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
- if (i2c_check_functionality(client->adapter,
- I2C_FUNC_SMBUS_READ_BYTE |
- I2C_FUNC_SMBUS_READ_WORD_DATA))
- slow = "word";
- else if (i2c_check_functionality(client->adapter,
- I2C_FUNC_SMBUS_READ_BYTE |
- I2C_FUNC_SMBUS_READ_BYTE_DATA))
- slow = "byte";
- else
- return -EPFNOSUPPORT;
- }
+ I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_READ_I2C_BLOCK) &&
+ !i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_READ_BYTE_DATA))
+ return -EPFNOSUPPORT;

/* Use 2 dummy devices for page select command */
mutex_lock(&ee1004_bus_lock);
@@ -218,10 +208,6 @@ static int ee1004_probe(struct i2c_client *client,
dev_info(&client->dev,
"%u byte EE1004-compliant SPD EEPROM, read-only\n",
EE1004_EEPROM_SIZE);
- if (slow)
- dev_notice(&client->dev,
- "Falling back to %s reads, performance will suffer\n",
- slow);

return 0;

--
2.31.1