Re: [PATCH-v3 02/11] i2c: pxa: No need to set slave addr for i2c master mode reset
From: Vaibhav Hiremath
Date: Fri Jul 10 2015 - 08:39:03 EST
On Friday 10 July 2015 01:41 PM, Wolfram Sang wrote:
On Tue, Jul 07, 2015 at 12:54:46AM +0530, Vaibhav Hiremath wrote:
Normally i2c controller works as master, so slave addr is not needed, or it
will impact some slave device (eg. ST NFC chip) i2c accesses, because it has
the same i2c address with controller.
Just to make sure: Does it? As I read the code, slave interrupts are
enabled later only when slave mode is selected? Is that a HW bug? And if
so, can't the code just be moved into this #ifdef block later?
Yes we could, infact I thought about it;
but I would break recommended sequence here.
As per spec, it only says,
The SocC writes this register before it enable TWSI operations.
I decided not to break the existing sequence and just fix the code, as
I do can not validate slave mode of operation functionally. I do not
have slave mode setup with me.
Thanks,
Vaibhav
Signed-off-by: Jett.Zhou <jtzhou@xxxxxxxxxxx>
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@xxxxxxxxxx>
Acked-by: Robert Jarzmik <robert.jarzmik@xxxxxxx>
---
drivers/i2c/busses/i2c-pxa.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index f4ac8c5..023e59f 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -459,7 +459,7 @@ static void i2c_pxa_reset(struct pxa_i2c *i2c)
writel(I2C_ISR_INIT, _ISR(i2c));
writel(readl(_ICR(i2c)) & ~ICR_UR, _ICR(i2c));
- if (i2c->reg_isar)
+ if (i2c->reg_isar && IS_ENABLED(CONFIG_I2C_PXA_SLAVE))
writel(i2c->slave_addr, _ISAR(i2c));
/* set control register values */
--
1.9.1
--
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/