On 01/18/2017 07:23 PM, mar.krzeminski wrote:
> W dniu 18.01.2017 o 16:01, Cédric Le Goater pisze:
>> When doing fast read, a certain amount of dummy bytes should be sent
>> before the read. This number is configurable in the controler CE0
>> Control Register and needs to be modeled using fake transfers to the
>> flash module.
>>
>> This only supports command mode. User mode requires more work and a
>> possible extension of the m25p80 device model.
>>
>> Signed-off-by: Cédric Le Goater <c...@kaod.org>
>> ---
>>
>> Changes since v2:
>>
>> - handled dummies under read routine and removed the test on the spi
>> command READ_FAST (0xb)
>>
>> hw/ssi/aspeed_smc.c | 21 +++++++++++++++++++++
>> 1 file changed, 21 insertions(+)
>>
>> diff --git a/hw/ssi/aspeed_smc.c b/hw/ssi/aspeed_smc.c
>> index a0a816407fc1..fc3cccec0566 100644
>> --- a/hw/ssi/aspeed_smc.c
>> +++ b/hw/ssi/aspeed_smc.c
>> @@ -69,7 +69,9 @@
>> #define R_CTRL0 (0x10 / 4)
>> #define CTRL_CMD_SHIFT 16
>> #define CTRL_CMD_MASK 0xff
>> +#define CTRL_DUMMY_HIGH_SHIFT 14
>> #define CTRL_AST2400_SPI_4BYTE (1 << 13)
>> +#define CTRL_DUMMY_LOW_SHIFT 6 /* 2 bits [7:6] */
>> #define CTRL_CE_STOP_ACTIVE (1 << 2)
>> #define CTRL_CMD_MODE_MASK 0x3
>> #define CTRL_READMODE 0x0
>> @@ -490,6 +492,16 @@ static uint32_t aspeed_smc_check_segment_addr(const
>> AspeedSMCFlash *fl,
>> return addr;
>> }
>> +static int aspeed_smc_flash_dummies(const AspeedSMCFlash *fl)
>> +{
>> + const AspeedSMCState *s = fl->controller;
>> + uint32_t r_ctrl0 = s->regs[s->r_ctrl0 + fl->id];
>> + uint32_t dummy_high = (r_ctrl0 >> CTRL_DUMMY_HIGH_SHIFT) & 0x1;
>> + uint32_t dummy_low = (r_ctrl0 >> CTRL_DUMMY_LOW_SHIFT) & 0x3;
>> +
>> + return ((dummy_high << 2) | dummy_low) * 8;
>> +}
>> +
>> static void aspeed_smc_flash_send_addr(AspeedSMCFlash *fl, uint32_t addr)
>> {
>> const AspeedSMCState *s = fl->controller;
>> @@ -526,6 +538,15 @@ static uint64_t aspeed_smc_flash_read(void *opaque,
>> hwaddr addr, unsigned size)
>> aspeed_smc_flash_select(fl);
>> aspeed_smc_flash_send_addr(fl, addr);
>> + /*
>> + * Use fake transfers to model dummy bytes. The value should
>> + * be configured to some non-zero value in fast read mode and
>> + * zero in read mode.
>> + */
>> + for (i = 0; i < aspeed_smc_flash_dummies(fl); i++) {
>> + ssi_transfer(fl->controller->spi, 0xFF);
>> + }
>> +
>> for (i = 0; i < size; i++) {
>> ret |= ssi_transfer(s->spi, 0x0) << (8 * i);
>> }
> If it does not break CTRL_WRITEMODE then:
> Acked-by: Marcin Krzemiński <mar.krzemin...@gmail.com>
yes. now the dummy transfers are under the CTRL_FREADMODE case,
which is the same as CTRL_READMODE but in this case, the number
of dummies should zero.
Thanks,
C.
