[PATCH 04/12] i2c: pxa: Add support for pxa910/988 & new configuration features
Vaibhav Hiremath
vaibhav.hiremath at linaro.org
Wed Jun 3 22:46:09 PDT 2015
On Thursday 04 June 2015 08:01 AM, Yi Zhang wrote:
> On Fri, May 29, 2015 at 10:22:27PM +0200, Robert Jarzmik wrote:
>> Vaibhav Hiremath <vaibhav.hiremath at linaro.org> writes:
>>
>>> @@ -167,6 +184,8 @@ struct pxa_i2c {
>>> #define _ICR(i2c) ((i2c)->reg_icr)
>>> #define _ISR(i2c) ((i2c)->reg_isr)
>>> #define _ISAR(i2c) ((i2c)->reg_isar)
>>> +#define _ILCR(i2c) ((i2c)->reg_ilcr)
>>> +#define _IWCR(i2c) ((i2c)->reg_iwcr)
>>>
>>> /*
>>> * I2C Slave mode address
>>> @@ -467,11 +486,16 @@ static void i2c_pxa_reset(struct pxa_i2c *i2c)
>>> if (i2c->reg_isar)
>>> writel(i2c->slave_addr, _ISAR(i2c));
>>> #endif
>>> -
>> Not in this patch.
>>
>>> /* set control register values */
>>> writel(I2C_ICR_INIT | (i2c->fast_mode ? ICR_FM : 0), _ICR(i2c));
>>> writel(readl(_ICR(i2c)) | (i2c->high_mode ? ICR_HS : 0), _ICR(i2c));
>>>
>>> + if (i2c->ilcr)
>>> + writel(i2c->ilcr, _ILCR(i2c));
>>> + if (i2c->iwcr)
>>> + writel(i2c->iwcr, _IWCR(i2c));
>>> + udelay(2);
>> This is a magical 2us. Where does it come from ?
>
> This delay can be removed, if writing LCR and WCR before enabling this
> i2c controller, it's safe enough; and they should not be changed when
> there is bus activity.
I have already removed it in my next version.
Thanks,
Vaibhav
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