On 9/29/20 3:51 PM, Pratyush Yadav wrote:
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>
> On 29/09/20 11:26AM, tudor.amba...@microchip.com wrote:
>> Hi,
>>
>> On 9/16/20 3:44 PM, Pratyush Yadav wrote:
>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the
>>> content is safe
>>>
>>> Allow flashes to specify a hook to enable octal DTR mode. Use this hook
>>> whenever possible to get optimal transfer speeds.
>>>
>>> Signed-off-by: Pratyush Yadav <p.ya...@ti.com>
>>> ---
>>> drivers/mtd/spi-nor/core.c | 35 +++++++++++++++++++++++++++++++++++
>>> drivers/mtd/spi-nor/core.h | 2 ++
>>> 2 files changed, 37 insertions(+)
>>>
>>> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
>>> index 87c568debf14..6ee93544d72f 100644
>>> --- a/drivers/mtd/spi-nor/core.c
>>> +++ b/drivers/mtd/spi-nor/core.c
>>> @@ -3069,6 +3069,35 @@ static int spi_nor_init_params(struct spi_nor *nor)
>>> return 0;
>>> }
>>>
>>> +/** spi_nor_octal_dtr_enable() - enable Octal DTR I/O if needed
>>> + * @nor: pointer to a 'struct spi_nor'
>>> + * @enable: whether to enable or disable Octal DTR
>>> + *
>>> + * Return: 0 on success, -errno otherwise.
>>> + */
>>> +static int spi_nor_octal_dtr_enable(struct spi_nor *nor, bool enable)
>>> +{
>>> + int ret;
>>> +
>>> + if (!nor->params->octal_dtr_enable)
>>> + return 0;
>>> +
>>> + if (!(nor->read_proto == SNOR_PROTO_8_8_8_DTR &&
>>> + nor->write_proto == SNOR_PROTO_8_8_8_DTR))
>>> + return 0;
>>> +
>>> + ret = nor->params->octal_dtr_enable(nor, enable);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + if (enable)
>>> + nor->reg_proto = SNOR_PROTO_8_8_8_DTR;
>>> + else
>>> + nor->reg_proto = SNOR_PROTO_1_1_1;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> /**
>>> * spi_nor_quad_enable() - enable/disable Quad I/O if needed.
>>> * @nor: pointer to a 'struct spi_nor'
>>> @@ -3109,6 +3138,12 @@ static int spi_nor_init(struct spi_nor *nor)
>>> {
>>> int err;
>>>
>>> + err = spi_nor_octal_dtr_enable(nor, true);
>>> + if (err) {
>>> + dev_dbg(nor->dev, "octal mode not supported\n");
>>> + return err;
>>> + }
>>> +
>>> err = spi_nor_quad_enable(nor, true);
>>
>> Is it possible to enable octal dtr and quad at the same time?
>> Maybe an 'if/else if' here depending on the values of nor->read_proto and
>> nor->write_proto
>
> No it is not. If you look inside spi_nor_octal_dtr_enable() and
> spi_nor_quad_enable(), they both are a no-op if the protocol does not
> match. spi_nor_quad_enable() was already doing it this way so I made
> spi_nor_octal_dtr_enable() follow suit. So this is effectively an
> if-else on the value of nor->read_proto. I don't think an explicit one
> is needed.
you're right! thanks
