[PATCH 2/3] viafb: fix I2C emulation on GPIO ports

From: Florian Tobias Schandinat
Date: Tue Feb 14 2012 - 01:14:50 EST


This patch fixes the I2C emulation on GPIO ports by enabling it
(software controlled) and disabling the output on a GPIO line before
reading it.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@xxxxxx>
---
drivers/video/via/via_i2c.c | 10 ++++++++--
1 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/video/via/via_i2c.c b/drivers/video/via/via_i2c.c
index 78f1405..dd53058 100644
--- a/drivers/video/via/via_i2c.c
+++ b/drivers/video/via/via_i2c.c
@@ -51,7 +51,7 @@ static void via_i2c_setscl(void *data, int state)
val |= 0x01;
break;
case VIA_PORT_GPIO:
- val |= 0x80;
+ val |= 0x82;
break;
default:
printk(KERN_ERR "viafb_i2c: specify wrong i2c type.\n");
@@ -67,6 +67,9 @@ static int via_i2c_getscl(void *data)
int ret = 0;

spin_lock_irqsave(&i2c_vdev->reg_lock, flags);
+ if (adap_data->type == VIA_PORT_GPIO)
+ via_write_reg_mask(adap_data->io_port, adap_data->ioport_index,
+ 0, 0x80);
if (via_read_reg(adap_data->io_port, adap_data->ioport_index) & 0x08)
ret = 1;
spin_unlock_irqrestore(&i2c_vdev->reg_lock, flags);
@@ -80,6 +83,9 @@ static int via_i2c_getsda(void *data)
int ret = 0;

spin_lock_irqsave(&i2c_vdev->reg_lock, flags);
+ if (adap_data->type == VIA_PORT_GPIO)
+ via_write_reg_mask(adap_data->io_port, adap_data->ioport_index,
+ 0, 0x40);
if (via_read_reg(adap_data->io_port, adap_data->ioport_index) & 0x04)
ret = 1;
spin_unlock_irqrestore(&i2c_vdev->reg_lock, flags);
@@ -103,7 +109,7 @@ static void via_i2c_setsda(void *data, int state)
val |= 0x01;
break;
case VIA_PORT_GPIO:
- val |= 0x40;
+ val |= 0x42;
break;
default:
printk(KERN_ERR "viafb_i2c: specify wrong i2c type.\n");
--
1.7.9

--
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/