On 10/3/22 13:06, Potthuri, Sai Krishna wrote:
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>
> Hi Tudor Ambarus,
>
>> -----Original Message-----
>> From: Tudor.Ambarus@xxxxxxxxxxxxx <Tudor.Ambarus@xxxxxxxxxxxxx>
>> Sent: Monday, October 3, 2022 3:13 PM
>> To: Potthuri, Sai Krishna <sai.krishna.potthuri@xxxxxxx>;
>> pratyush@xxxxxxxxxx; michael@xxxxxxxx; miquel.raynal@xxxxxxxxxxx;
>> richard@xxxxxx; vigneshr@xxxxxx; robh+dt@xxxxxxxxxx;
>> krzysztof.kozlowski+dt@xxxxxxxxxx
>> Cc: devicetree@xxxxxxxxxxxxxxx; linux-mtd@xxxxxxxxxxxxxxxxxxx; linux-
>> kernel@xxxxxxxxxxxxxxx; saikrishna12468@xxxxxxxxx; git (AMD-Xilinx)
>> <git@xxxxxxx>
>> Subject: Re: [PATCH v3 2/2] mtd: spi-nor: Add support for flash reset
>>
>> On 9/8/22 09:44, Sai Krishna Potthuri wrote:
>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know
>>> the content is safe
>>>
>>> Add support for spi-nor flash reset via GPIO controller by reading the
>>> reset-gpio property. If there is a valid GPIO specifier then reset
>>> will be performed by asserting and deasserting the GPIO using gpiod
>>> APIs otherwise it will not perform any operation.
>>>
>>> Signed-off-by: Sai Krishna Potthuri <sai.krishna.potthuri@xxxxxxx>
>>> Reviewed-by: Michael Walle <michael@xxxxxxxx>
>>> ---
>>> drivers/mtd/spi-nor/core.c | 25 +++++++++++++++++++++++++
>>> 1 file changed, 25 insertions(+)
>>>
>>> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
>>> index f2c64006f8d7..a78ab9bae2be 100644
>>> --- a/drivers/mtd/spi-nor/core.c
>>> +++ b/drivers/mtd/spi-nor/core.c
>>> @@ -2933,6 +2933,27 @@ static void spi_nor_set_mtd_info(struct spi_nor
>> *nor)
>>> mtd->_put_device = spi_nor_put_device; }
>>>
>>> +static int spi_nor_hw_reset(struct spi_nor *nor) {
>>> + struct gpio_desc *reset;
>>> +
>>> + reset = devm_gpiod_get_optional(nor->dev, "reset",
>> GPIOD_OUT_LOW);
>>> + if (IS_ERR_OR_NULL(reset))
>>> + return PTR_ERR_OR_ZERO(reset);
>>> +
>>> + /*
>>> + * Experimental delay values by looking at different flash device
>>> + * vendors datasheets.
>>> + */
>>> + usleep_range(1, 5);
>>> + gpiod_set_value_cansleep(reset, 1);
>>> + usleep_range(100, 150);
>>> + gpiod_set_value_cansleep(reset, 0);
>>> + usleep_range(1000, 1200);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> int spi_nor_scan(struct spi_nor *nor, const char *name,
>>> const struct spi_nor_hwcaps *hwcaps) { @@ -2965,6
>>> +2986,10 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
>>> if (!nor->bouncebuf)
>>> return -ENOMEM;
>>>
>>> + ret = spi_nor_hw_reset(nor);
>>
>> Should we condition the calling of this method by the absence of the
>> "broken-flash-reset"
>> dt prop?
> This is the suggestion from Michael on top of my initial series for which
> i also agreed to have this call unconditionally. If device tree is having this
> reset property then we can do the reset in any case.
>
Okay.
--
Cheers,
ta
