[PATCH-v3 02/11] i2c: pxa: No need to set slave addr for i2c master mode reset
vaibhav.hiremath at linaro.org
Fri Jul 10 05:38:43 PDT 2015
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.
>> Signed-off-by: Jett.Zhou <jtzhou at marvell.com>
>> Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath at linaro.org>
>> Acked-by: Robert Jarzmik <robert.jarzmik at free.fr>
>> 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 */
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