[U-Boot] [PATCH] mtd: nand: denali_dt: Add reset support

[Marek Vasut]

On 08/24/2018 03:05 PM, Masahiro Yamada wrote:
> Hi Marek,

Hi,

> 2018-08-21 22:57 GMT+09:00 Marek Vasut <marex at denx.de>:
>> Add optional reset support into the Denali NAND driver. In case there is
>> a valid reset entry in the DT, the reset gets deasserted before the NAND
>> controller gets used.
>>
>> Signed-off-by: Marek Vasut <marex at denx.de>
>> Cc: Masahiro Yamada <yamada.masahiro at socionext.com>
>> ---
>>  drivers/mtd/nand/denali_dt.c | 9 +++++++++
>>  1 file changed, 9 insertions(+)
>>
>> diff --git a/drivers/mtd/nand/denali_dt.c b/drivers/mtd/nand/denali_dt.c
>> index 65a7797f0f..6fcd7d3843 100644
>> --- a/drivers/mtd/nand/denali_dt.c
>> +++ b/drivers/mtd/nand/denali_dt.c
>> @@ -9,6 +9,7 @@
>>  #include <linux/io.h>
>>  #include <linux/ioport.h>
>>  #include <linux/printk.h>
>> +#include <reset.h>
>>
>>  #include "denali.h"
>>
>> @@ -64,6 +65,7 @@ static int denali_dt_probe(struct udevice *dev)
>>         const struct denali_dt_data *data;
>>         struct clk clk;
>>         struct resource res;
>> +       struct reset_ctl reset_ctl;
>>         int ret;
>>
>>         data = (void *)dev_get_driver_data(dev);
>> @@ -97,6 +99,13 @@ static int denali_dt_probe(struct udevice *dev)
>>
>>         denali->clk_x_rate = clk_get_rate(&clk);
>>
>> +       ret = reset_get_by_index(dev, 0, &reset_ctl);
>> +       if (!ret) {
>> +               reset_assert(&reset_ctl);
>> +               udelay(2);
>> +               reset_deassert(&reset_ctl);
>> +       }
>> +
>>         return denali_init(denali);
>>  }
>>
> 
> 
> I was testing this patch today
> because my SoC also has a reset line for NAND.
> 
> 
> This patch looks trivial enough,
> but if the NAND is reset here,
> my board fails to boot with
> "nand_base: timeout while waiting for chip to become ready"
> 
> 
> I do not know why.
> Please give me more time to figure out what is going on in my SoC.

Sure. Maybe you need to un-reset more stuff or the reset polarity is wrong ?

-- 
Best regards,
Marek Vasut