Re: [PATCH v6 13/14] mtd: onenand: omap2: Configure driver from DT

[Aaro Koskinen <aaro.koskinen@xxxxxx>]

Hi,

On Fri, Jan 12, 2018 at 02:17:25PM +0100, Ladislav Michl wrote:
> Move away from platform data configuration and use pure DT approach.

Unfortunately this patch (now commit a758f50f10cf) has broken onenand
probe on N9/N950:

[    3.129364] OneNAND Manufacturer: Unknown (0xa0)

The init order was changed so that onenand_scan() is called before the
timings are configured:

>  	if ((r = onenand_scan(&c->mtd, 1)) < 0)
>  		goto err_release_dma;
>  
> +	freq = omap2_onenand_get_freq(c->onenand.version_id);
> +	if (freq > 0) {
> +		switch (freq) {
> +		case 104:
> +			latency = 7;
> +			break;
> +		case 83:
> +			latency = 6;
> +			break;
> +		case 66:
> +			latency = 5;
> +			break;
> +		case 56:
> +			latency = 4;
> +			break;
> +		default:	/* 40 MHz or lower */
> +			latency = 3;
> +			break;
> +		}
> +
> +		r = gpmc_omap_onenand_set_timings(dev, c->gpmc_cs,
> +						  freq, latency, &info);
> +		if (r)
> +			goto err_release_onenand;
> +
> +		r = omap2_onenand_set_cfg(c, info.sync_read, info.sync_write,
> +					  latency, info.burst_len);
> +		if (r)
> +			goto err_release_onenand;
> +
> +		if (info.sync_read || info.sync_write)
> +			dev_info(dev, "optimized timings for %d MHz\n", freq);
> +	}

But looks like on N9/N950 we need to do the configuration for the
onenand_scan() to succeed. I guess the order has to be this because we
have no other way to know "version_id".

I tested by changing this other way round (and hardcoding the freq manually)
and it seems to work.

A.

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