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SubjectRe: [PATCH v2 1/3] mmc: sdhci: introduce sdhci_compute_clock_config
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On 06/04/16 18:04, Ludovic Desroches wrote:
> On Wed, Apr 06, 2016 at 03:37:28PM +0300, Adrian Hunter wrote:
>> On 04/04/16 18:27, Ludovic Desroches wrote:
>>> In order to remove the SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST and to
>>> reduce code duplication, put the code relative to the SD clock
>>> configuration in a function which can be used by hosts for the
>>> implementation of the set_clock() callback.
>>>
>>> Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
>>> ---
>>> drivers/mmc/host/sdhci.c | 33 ++++++++++++++++++++++-----------
>>> drivers/mmc/host/sdhci.h | 1 +
>>> 2 files changed, 23 insertions(+), 11 deletions(-)
>>>
>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>> index 6bd3d17..2c3dede 100644
>>> --- a/drivers/mmc/host/sdhci.c
>>> +++ b/drivers/mmc/host/sdhci.c
>>> @@ -1091,23 +1091,13 @@ static u16 sdhci_get_preset_value(struct sdhci_host *host)
>>> return preset;
>>> }
>>>
>>> -void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
>>> +u16 sdhci_compute_clock_config(struct sdhci_host *host, unsigned int clock)
>>
>> The function name 'sdhci_compute_clock_config' seems a bit long. How about
>> just sdhci_calc_clk.
>
> Ok.
>
>>
>> Also it needs to calculate 'actual_clock' too, so it needs to do that and
>> return the value.
>>
>
> actual_clock is updated at the end of the function.
>
> Which value has to be returned? actual_clock or clock configuration?

The function doesn't update the clock, so I don't think it should update
actual_clock either, just return it. i.e.

u16 sdhci_calc_clk(struct sdhci_host *host, unsigned int clock, unsigned int *actual_clock)
{
...
if (real_div)
*actual_clock = (host->max_clk * clk_mul) / real_div;
...
return clk;
}

then

clk = sdhci_calc_clk(host, clock, &host->mmc->actual_clock);



>
> Regards
>
> Ludovic
>
>>> {
>>> int div = 0; /* Initialized for compiler warning */
>>> int real_div = div, clk_mul = 1;
>>> u16 clk = 0;
>>> - unsigned long timeout;
>>> bool switch_base_clk = false;
>>>
>>> - host->mmc->actual_clock = 0;
>>> -
>>> - sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
>>> - if (host->quirks2 & SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST)
>>> - mdelay(1);
>>> -
>>> - if (clock == 0)
>>> - return;
>>> -
>>> if (host->version >= SDHCI_SPEC_300) {
>>> if (host->preset_enabled) {
>>> u16 pre_val;
>>> @@ -1188,6 +1178,27 @@ clock_set:
>>> clk |= (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
>>> clk |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIV_MASK_LEN)
>>> << SDHCI_DIVIDER_HI_SHIFT;
>>> +
>>> + return clk;
>>> +}
>>> +EXPORT_SYMBOL_GPL(sdhci_compute_clock_config);
>>> +
>>> +void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
>>> +{
>>> + u16 clk;
>>> + unsigned long timeout;
>>> +
>>> + host->mmc->actual_clock = 0;
>>> +
>>> + sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
>>> + if (host->quirks2 & SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST)
>>> + mdelay(1);
>>> +
>>> + if (clock == 0)
>>> + return;
>>> +
>>> + clk = sdhci_compute_clock_config(host, clock);
>>> +
>>> clk |= SDHCI_CLOCK_INT_EN;
>>> sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
>>>
>>> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
>>> index 0f39f4f..23ddd6e 100644
>>> --- a/drivers/mmc/host/sdhci.h
>>> +++ b/drivers/mmc/host/sdhci.h
>>> @@ -661,6 +661,7 @@ static inline bool sdhci_sdio_irq_enabled(struct sdhci_host *host)
>>> return !!(host->flags & SDHCI_SDIO_IRQ_ENABLED);
>>> }
>>>
>>> +u16 sdhci_compute_clock_config(struct sdhci_host *host, unsigned int clock);
>>> void sdhci_set_clock(struct sdhci_host *host, unsigned int clock);
>>> void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
>>> unsigned short vdd);
>>>
>>
>

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