[PATCH v4 01/39] ARM: OMAP2+: gpmc: driver conversion
Jon Hunter
jon-hunter at ti.com
Mon May 7 12:02:58 EDT 2012
Hi Afzal,
On 05/07/2012 06:01 AM, Mohammed, Afzal wrote:
> Hi Jon,
>
> On Fri, May 04, 2012 at 21:57:10, Hunter, Jon wrote:
>>> - gpmc_write_reg(GPMC_SYSCONFIG, l);
>>> - gpmc_mem_init();
>>> + switch (conf & GPMC_WAITPIN_MASK) {
>>> + case GPMC_WAITPIN_0:
>>> + idx = GPMC_WAITPIN_IDX0;
>>> + break;
>>> + case GPMC_WAITPIN_1:
>>> + idx = GPMC_WAITPIN_IDX1;
>>> + break;
>>> + case GPMC_WAITPIN_2:
>>> + idx = GPMC_WAITPIN_IDX2;
>>> + break;
>>> + case GPMC_WAITPIN_3:
>>> + idx = GPMC_WAITPIN_IDX3;
>>> + break;
>>> + /* no waitpin */
>>> + case 0:
>>> + break;
>>> + default:
>>> + dev_err(gpmc->dev, "multiple waitpins selected on CS:%u\n", cs);
>>> + return -EINVAL;
>>> + break;
>>> + }
>>
>> Why not combined case 0 and default? Both are invalid configurations so
>> just report invalid selection.
>
> Case 0 is not invalid, a case where waitpin is not used, default refers
> to when a user selects multiple waitpins wrongly.
Ok. Then for case 0, just return here. If the polarity is set, you could
print an error here.
>>
>>>
>>> - /* initalize the irq_chained */
>>> - irq = OMAP_GPMC_IRQ_BASE;
>>> - for (cs = 0; cs < GPMC_CS_NUM; cs++) {
>>> - irq_set_chip_and_handler(irq, &dummy_irq_chip,
>>> - handle_simple_irq);
>>> - set_irq_flags(irq, IRQF_VALID);
>>> - irq++;
>>> + switch (conf & GPMC_WAITPIN_POLARITY_MASK) {
>>> + case GPMC_WAITPIN_ACTIVE_LOW:
>>> + polarity = LOW;
>>> + break;
>>> + case GPMC_WAITPIN_ACTIVE_HIGH:
>>> + polarity = HIGH;
>>> + break;
>>> + /* no waitpin */
>>> + case 0:
>>> + break;
>>> + default:
>>> + dev_err(gpmc->dev, "waitpin polarity set to low & high\n");
>>> + return -EINVAL;
>>> + break;
>>> }
>>
>> Again, combine case 0 and default as these are invalid.
>
> Similar to above
If you return above, then case 0 is not needed.
>>
>>> + if (gd->have_waitpin) {
>>> + if (gd->waitpin != idx ||
>>> + gd->waitpin_polarity != polarity) {
>>> + dev_err(gpmc->dev, "error: conflict: waitpin %u with polarity %d on device %s.%d\n",
>>> + gd->waitpin, gd->waitpin_polarity,
>>> + gd->name, gd->id);
>>> + return -EBUSY;
>>> + }
>>> + } else {
>>
>> Don't need the else as you are going to return in the above.
>
> Not always, only in case of error
Ok, but seems that it can be simplified a little.
What happens if a device uses more than one wait-pin? In other words a
device with two chip-selects that uses two wait-pins?
>>
>>> + gd->have_waitpin = true;
>>> + gd->waitpin = idx;
>>> + gd->waitpin_polarity = polarity;
>>> + }
>>> +
>>> + l &= ~GPMC_CONFIG1_WAIT_PIN_SEL_MASK;
>>> + l |= GPMC_CONFIG1_WAIT_PIN_SEL(idx);
>>> + gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, l);
>>> + } else if (polarity) {
>>> + dev_err(gpmc->dev, "error: waitpin polarity specified with out wait pin number on device %s.%d\n",
>>> + gd->name, gd->id);
>>> + return -EINVAL;
>>
>> Drop this else-if. The above switch statements will report the bad
>> configuration. This seems a bit redundant.
>
> This is required as switch statements will not report error if polarity
> is specified, w/o waitpin to be used.
Ok, may be you can print that above when you detect that there are no
wait-pins selected.
Jon
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