net: phy: b53: Add b53_reg read/write commands

Add a b53_reg read/write command which allows inspecting the switch
registers. Because the Broadcom BCM53xx registers have different sizes,
we need to split the accesses in 8, 16, 32, 48 or 64 bits to obtain
expected results.

Reviewed-by: Stefan Roese <sr@denx.de>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

drivers/net/phy/b53.c

@@ -627,3 +627,142 @@ int phy_b53_init(void)
 
 	return 0;
 }
+
+int do_b53_reg_read(const char *name, int argc, char * const argv[])
+{
+	u8 page, offset, width;
+	struct mii_dev *bus;
+	int ret = -EINVAL;
+	u64 value64 = 0;
+	u32 value32 = 0;
+	u16 value16 = 0;
+	u8 value8 = 0;
+
+	bus = miiphy_get_dev_by_name(name);
+	if (!bus) {
+		printf("unable to find MDIO bus: %s\n", name);
+		return ret;
+	}
+
+	page = simple_strtoul(argv[1], NULL, 16);
+	offset = simple_strtoul(argv[2], NULL, 16);
+	width = simple_strtoul(argv[3], NULL, 10);
+
+	switch (width) {
+	case 8:
+		ret = b53_mdio_read8(bus, page, offset, &value8);
+		printf("page=0x%02x, offset=0x%02x, value=0x%02x\n",
+		       page, offset, value8);
+		break;
+	case 16:
+		ret = b53_mdio_read16(bus, page, offset, &value16);
+		printf("page=0x%02x, offset=0x%02x, value=0x%04x\n",
+		       page, offset, value16);
+		break;
+	case 32:
+		ret = b53_mdio_read32(bus, page, offset, &value32);
+		printf("page=0x%02x, offset=0x%02x, value=0x%08x\n",
+		       page, offset, value32);
+		break;
+	case 48:
+		ret = b53_mdio_read48(bus, page, offset, &value64);
+		printf("page=0x%02x, offset=0x%02x, value=0x%012llx\n",
+		       page, offset, value64);
+		break;
+	case 64:
+		ret = b53_mdio_read48(bus, page, offset, &value64);
+		printf("page=0x%02x, offset=0x%02x, value=0x%016llx\n",
+		       page, offset, value64);
+		break;
+	default:
+		printf("Unsupported width: %d\n", width);
+		break;
+	}
+
+	return ret;
+}
+
+int do_b53_reg_write(const char *name, int argc, char * const argv[])
+{
+	u8 page, offset, width;
+	struct mii_dev *bus;
+	int ret = -EINVAL;
+	u64 value64 = 0;
+	u32 value = 0;
+
+	bus = miiphy_get_dev_by_name(name);
+	if (!bus) {
+		printf("unable to find MDIO bus: %s\n", name);
+		return ret;
+	}
+
+	page = simple_strtoul(argv[1], NULL, 16);
+	offset = simple_strtoul(argv[2], NULL, 16);
+	width = simple_strtoul(argv[3], NULL, 10);
+	if (width == 48 || width == 64)
+		value64 = simple_strtoull(argv[4], NULL, 16);
+	else
+		value = simple_strtoul(argv[4], NULL, 16);
+
+	switch (width) {
+	case 8:
+		ret = b53_mdio_write8(bus, page, offset, value & 0xff);
+		break;
+	case 16:
+		ret = b53_mdio_write16(bus, page, offset, value);
+		break;
+	case 32:
+		ret = b53_mdio_write32(bus, page, offset, value);
+		break;
+	case 48:
+		ret = b53_mdio_write48(bus, page, offset, value64);
+		break;
+	case 64:
+		ret = b53_mdio_write64(bus, page, offset, value64);
+		break;
+	default:
+		printf("Unsupported width: %d\n", width);
+		break;
+	}
+
+	return ret;
+}
+
+int do_b53_reg(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	const char *cmd, *mdioname;
+	int ret = 0;
+
+	if (argc < 2)
+		return cmd_usage(cmdtp);
+
+	cmd = argv[1];
+	--argc;
+	++argv;
+
+	if (!strcmp(cmd, "write")) {
+		if (argc < 4)
+			return cmd_usage(cmdtp);
+		mdioname = argv[1];
+		--argc;
+		++argv;
+		ret = do_b53_reg_write(mdioname, argc, argv);
+	} else if (!strcmp(cmd, "read")) {
+		if (argc < 5)
+			return cmd_usage(cmdtp);
+		mdioname = argv[1];
+		--argc;
+		++argv;
+		ret = do_b53_reg_read(mdioname, argc, argv);
+	} else {
+		return cmd_usage(cmdtp);
+	}
+
+	return ret;
+}
+
+U_BOOT_CMD(b53_reg, 7, 1, do_b53_reg,
+	   "Broadcom B53 switch register access",
+	   "write mdioname page (hex) offset (hex) width (dec) value (hex)\n"
+	   "read mdioname page (hex) offset (hex) width (dec)\n"
+	  );