Re: [RESEND v2] soc: imx: Add generic i.MX8 SoC driver

[Leonard Crestez]

On 3/28/2019 6:43 PM, Leonard Crestez wrote:
> On Fri, 2019-03-22 at 16:49 +0000, Abel Vesa wrote:
>> Add generic i.MX8 SoC driver along with the i.MX8MQ SoC specific code.
>> For now, only i.MX8MQ revision B1 is supported. For any other, i.MX8MQ
>> revision it will print 'unknown'.
> 
>> +#define REV_B1				0x21
>> +
>> +#define IMX8MQ_SW_INFO_B1		0x40
>> +#define IMX8MQ_SW_MAGIC_B1		0xff0055aa
>> +
>> +	np = of_find_compatible_node(NULL, NULL, "fsl,imx8mq-ocotp");+
>> +	ocotp_base = of_iomap(np, 0);
>> +
>> +	magic = readl_relaxed(ocotp_base + IMX8MQ_SW_INFO_B1);
>> +	if (magic == IMX8MQ_SW_MAGIC_B1)
>> +		rev = REV_B1;
> 
> This is based on ATF code in vendor tree, but shouldn't we have some
> sort of explanation for this "magic"?
> 
> Looking at the OCOTP driver reg 0x40 is IMX_OCOTP_ADDR_DATA2 and it's
> used as part of fuse writes. According to the driver code 8mq is
> compatible with 7d and this write path is enabled for imx8mq-ocotp.

After further digging in NXP manuals and uboot sources it seems that 
imx8mq ocotp is like imx6 rather than imx7. Posted fix for nvmem driver:

https://patchwork.kernel.org/patch/10908081/

Reviewed-by: Leonard Crestez <leonard.crestez@xxxxxxx>

It might still be nice to find a way to identify imx8mq B0.