Re: [PATCH 1/2] arm: rmobile: Add RZ/G2M SoC

On 9/18/20 6:03 PM, Biju Das wrote:

Add CPU and PRR IDs for R8A774A1(a.k.a RZ/G2M) SoC.

[...]

+static const struct udevice_id *of_soc_match_compatible(void) +{

• const struct udevice_id *of_match = soc_ids;
• int i;
• for (i = 0; i < ARRAY_SIZE(soc_ids); i++) {

• if (!fdt_node_check_compatible(gd->fdt_blob, 0,
  

• 			       of_match->compatible))
  

• 	return of_match;
  

• of_match++;
  

• }
• return NULL;

+}

This should rather be a generic function, I think this is something that already exists in Linux common code too, right ?

static int rmobile_cpuinfo_idx(void) { int i = 0; u32 cpu_type = rmobile_get_cpu_type();

• const struct udevice_id *match = of_soc_match_compatible();

• /*

• * This loop identifies CPU based on PRR register, it differentiates
  

• * RZ/G SoC's from R-Car SoC's by matching RZ/G SoC compatible string
  

• * from DT against the family_type.
  

• */
  

  for (; i < ARRAY_SIZE(rmobile_cpuinfo); i++)

• if (rmobile_cpuinfo[i].cpu_type == cpu_type)
  

• 	break;
  

• if (rmobile_cpuinfo[i].cpu_type == cpu_type) {
  

• 	if (match &&
  

• 	    rmobile_cpuinfo[i].family_type == match->data)
  

• 		break;
  

• 	else if (!match &&
  

• 		 rmobile_cpuinfo[i].family_type != SOC_RZG2)
  

• 		break;
  

• }
  

I still don't understand this, so if cpu_type == RMOBILE_CPU_TYPE_R8A7796 , then it can be either RZG2 or R8A7796, right? And there is no PRR bit or any other bit to tell those two chips apart ?

I would like to avoid using the OF match here, because that fails if you use MULTI_DTB_FIT , does it not ? So can you please check whether there might be some way to tell the two SoCs apart ?