[U-Boot] [PATCH 3/3] mmc: bcm2835_sdhci: Add pinmux support

[Alexander Graf]

On 17.01.18 21:06, Simon Glass wrote:
> Hi Alex,
> 
> On 16 January 2018 at 05:46, Alexander Graf <agraf at suse.de> wrote:
>> The bcm2835 firmware provided device trees expect device tree users
>> to support pin muxing for the SD devices to work properly.
>>
>> This patch adds pin muxing support to the sdhci based SD controller
>> on said family of SoCs, so that its pins are getting configured
>> correctly on boot.
>>
>> Signed-off-by: Alexander Graf <agraf at suse.de>
>> ---
>>  drivers/mmc/bcm2835_sdhci.c | 11 +++++++++++
>>  1 file changed, 11 insertions(+)
>>
>> diff --git a/drivers/mmc/bcm2835_sdhci.c b/drivers/mmc/bcm2835_sdhci.c
>> index 3157354d2a..62ad109361 100644
>> --- a/drivers/mmc/bcm2835_sdhci.c
>> +++ b/drivers/mmc/bcm2835_sdhci.c
>> @@ -45,6 +45,7 @@
>>  #include <asm/arch/mbox.h>
>>  #include <mach/sdhci.h>
>>  #include <mach/timer.h>
>> +#include <mach/gpio.h>
>>
>>  /* 400KHz is max freq for card ID etc. Use that as min */
>>  #define MIN_FREQ 400000
>> @@ -178,6 +179,7 @@ static int bcm2835_sdhci_probe(struct udevice *dev)
>>         fdt_addr_t base;
>>         int emmc_freq;
>>         int ret;
>> +       int pinctrl_handle;
>>
>>         base = devfdt_get_addr(dev);
>>         if (base == FDT_ADDR_T_NONE)
>> @@ -190,6 +192,15 @@ static int bcm2835_sdhci_probe(struct udevice *dev)
>>         }
>>         emmc_freq = ret;
>>
>> +       pinctrl_handle = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev), "pinctrl-0", -1);
> 
> You can't do this sort of thing :-)
> 
> This should go in a pinctrl driver. The clue is that you are having to
> look up things manually here. You can create a basic driver very
> easily.

Yup, that's basically what I've spent today on :). Unfortunately my RPi
seems to corrupt its U-Boot binary on boot every so often, so some times
I end up with an unbootable system and I've been unable to actually
trace it down for real yet. For example some times I get weird
corruptions in the .dyn.rel section.

Either way, I've switched to network boot now, let's hope that makes
life easier. If things work out I'll send a new version tomorrow with an
actual pinmux driver that then instantiates the existing GPIO one as a
child (so that the pinmux one gets autoloaded).


Alex