Re: [Qemu-devel] [PATCH v4 19/20] sdcard: add a 'uhs' property, update the OCR register ACCEPT_SWITCH_1V8 bit

[Philippe Mathieu-Daudé]

Hi Peter,

On 02/22/2018 11:25 AM, Peter Maydell wrote:
> On 15 February 2018 at 22:13, Philippe Mathieu-Daudé <address@hidden> wrote:
>> Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
>> ---
>>  hw/sd/sd.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/hw/sd/sd.c b/hw/sd/sd.c
>> index ada96f5574..b9429b06ca 100644
>> --- a/hw/sd/sd.c
>> +++ b/hw/sd/sd.c
>> @@ -93,6 +93,7 @@ struct SDState {
>>      /* Configurable properties */
>>      BlockBackend *blk;
>>      bool spi;
>> +    uint8_t uhs_supported;
>>
>>      uint32_t mode;    /* current card mode, one of SDCardModes */
>>      int32_t state;    /* current card state, one of SDCardStates */
>> @@ -292,6 +293,8 @@ static void sd_set_ocr(SDState *sd)
>>  {
>>      /* All voltages OK */
>>      sd->ocr = R_OCR_VDD_VOLTAGE_WIN_HI_MASK;
>> +
>> +    sd->ocr = FIELD_DP32(sd->ocr, OCR, ACCEPT_SWITCH_1V8, 
>> !!sd->uhs_supported);
>>  }
>>
>>  static void sd_ocr_powerup(void *opaque)
>> @@ -2189,6 +2192,7 @@ static Property sd_properties[] = {
>>       * board to ensure that ssi transfers only occur when the chip select
>>       * is asserted.  */
>>      DEFINE_PROP_BOOL("spi", SDState, spi, false),
>> +    DEFINE_PROP_UINT8("uhs", SDState, uhs_supported, UHS_NOT_SUPPORTED),
>>      DEFINE_PROP_END_OF_LIST()
>>  };
> 
> The field name and the use of the value suggest that this is just
> a boolean flag, so why define it as a PROP_UINT8 rather than PROP_BOOL ?

Here is the full enum:

typedef enum  {
    UHS_NOT_SUPPORTED   = 0,
    UHS_I               = 1,
    UHS_II              = 2,    /* currently not supported */
    UHS_III             = 3,    /* currently not supported */
} sd_uhs_mode_t;

I'll rename it "uhs_mode" to reflect this is not a boolean.

Some controllers modeled support UHS-II, I guess we'll need to implement
it at some point during the year.

Regards,

Phil.