[PATCH 1/5] eeprom_93cx6: Add data direction control.

From: Stephen Boyd
Date: Wed Oct 26 2011 - 22:18:12 EST


From: Ben Dooks <ben@xxxxxxxxxxxx>

Some devices need to know if the data is to be output or read, so add a
data direction into the eeprom structure to tell the driver whether the
data line should be driven.

The user in this case is the Micrel KS8851 which has a direction
control for the EEPROM data line and thus needs to know whether
to drive it (writing) or to tristate it for receiving.

Signed-off-by: Ben Dooks <ben@xxxxxxxxxxxx>
Cc: Wolfram Sang <w.sang@xxxxxxxxxxxxxx>
Cc: Jean Delvare <khali@xxxxxxxxxxxx>
Cc: Linux Kernel <linux-kernel@xxxxxxxxxxxxxxx>
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
---
drivers/misc/eeprom/eeprom_93cx6.c | 3 +++
include/linux/eeprom_93cx6.h | 2 ++
2 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/misc/eeprom/eeprom_93cx6.c b/drivers/misc/eeprom/eeprom_93cx6.c
index 7b33de9..a6037af 100644
--- a/drivers/misc/eeprom/eeprom_93cx6.c
+++ b/drivers/misc/eeprom/eeprom_93cx6.c
@@ -63,6 +63,7 @@ static void eeprom_93cx6_startup(struct eeprom_93cx6 *eeprom)
eeprom->reg_data_out = 0;
eeprom->reg_data_clock = 0;
eeprom->reg_chip_select = 1;
+ eeprom->drive_data = 1;
eeprom->register_write(eeprom);

/*
@@ -101,6 +102,7 @@ static void eeprom_93cx6_write_bits(struct eeprom_93cx6 *eeprom,
*/
eeprom->reg_data_in = 0;
eeprom->reg_data_out = 0;
+ eeprom->drive_data = 1;

/*
* Start writing all bits.
@@ -140,6 +142,7 @@ static void eeprom_93cx6_read_bits(struct eeprom_93cx6 *eeprom,
*/
eeprom->reg_data_in = 0;
eeprom->reg_data_out = 0;
+ eeprom->drive_data = 0;

/*
* Start reading all bits.
diff --git a/include/linux/eeprom_93cx6.h b/include/linux/eeprom_93cx6.h
index c4627cb..e04546e 100644
--- a/include/linux/eeprom_93cx6.h
+++ b/include/linux/eeprom_93cx6.h
@@ -46,6 +46,7 @@
* @register_write(struct eeprom_93cx6 *eeprom): handler to
* write to the eeprom register by using all reg_* fields.
* @width: eeprom width, should be one of the PCI_EEPROM_WIDTH_* defines
+ * @drive_data: Set if we're driving the data line.
* @reg_data_in: register field to indicate data input
* @reg_data_out: register field to indicate data output
* @reg_data_clock: register field to set the data clock
@@ -62,6 +63,7 @@ struct eeprom_93cx6 {

int width;

+ char drive_data;
char reg_data_in;
char reg_data_out;
char reg_data_clock;
--
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

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