From: Chen-Yu Tsai <wens@xxxxxxxx>
On the Allwinner R40 SoC, the "GMAC clock" register is in the CCU
address space; on the A64 SoC this register is in the SRAM controller
address space, and with a different offset.
To access the register from another device and hide the internal
difference between the device, let it register a regmap named
"emac-clock". We can then get the device from the phandle, and
retrieve the regmap with dev_get_regmap(); in this situation the
regmap_field will be set up to access the only register in the regmap.
Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx>
[Icenowy: change to use regmaps with single register, change commit
message]
Signed-off-by: Icenowy Zheng <icenowy@xxxxxxx>
---
drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c | 48 ++++++++++++++++++++++-
1 file changed, 46 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
index 1037f6c78bca..b61210c0d415 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
@@ -85,6 +85,13 @@ const struct reg_field old_syscon_reg_field = {
.msb = 31,
};
+/* Specially exported regmap which contains only EMAC register */
+const struct reg_field single_reg_field = {
+ .reg = 0,
+ .lsb = 0,
+ .msb = 31,
+};
+
static const struct emac_variant emac_variant_h3 = {
.default_syscon_value = 0x58000,
.soc_has_internal_phy = true,
@@ -979,6 +986,44 @@ static struct mac_device_info *sun8i_dwmac_setup(void *ppriv)
return mac;
}
+static struct regmap *sun8i_dwmac_get_emac_regmap(struct sunxi_priv_data *emac,
+ struct device_node *node)
+{
+ struct device_node *syscon_node;
+ struct platform_device *syscon_pdev = NULL;
+ struct regmap *regmap = NULL;
+
+ syscon_node = of_parse_phandle(node, "syscon", 0);
+ if (!syscon_node)
+ return ERR_PTR(-ENODEV);
+
+ if (of_device_is_compatible(syscon_node, "syscon")) {
+ regmap = syscon_regmap_lookup_by_phandle(node, "syscon");
+
+ emac->emac_reg_field = &old_syscon_reg_field;
+ } else {
+ syscon_pdev = of_find_device_by_node(syscon_node);
+ if (!syscon_pdev) {
+ /* platform device might not be probed yet */
+ regmap = ERR_PTR(-EPROBE_DEFER);
+ goto out_put_node;
+ }
+
+ /* If no regmap is found then trap into error */
+ regmap = dev_get_regmap(&syscon_pdev->dev, "emac-clock");
+ if (!regmap)
+ regmap = ERR_PTR(-EINVAL);
+
+ emac->emac_reg_field = &single_reg_field;
+ }
+
+ if (syscon_pdev)
+ platform_device_put(syscon_pdev);
+out_put_node:
+ of_node_put(syscon_node);
+ return regmap;
+}
+
static int sun8i_dwmac_probe(struct platform_device *pdev)
{
struct plat_stmmacenet_data *plat_dat;
@@ -1023,13 +1068,12 @@ static int sun8i_dwmac_probe(struct platform_device *pdev)
gmac->regulator = NULL;
}
- regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "syscon");
+ regmap = sun8i_dwmac_get_emac_regmap(gmac, pdev->dev.of_node);
if (IS_ERR(regmap)) {
ret = PTR_ERR(regmap);
dev_err(&pdev->dev, "Unable to map syscon: %d\n", ret);
return ret;
}
- gmac->emac_reg_field = old_syscon_reg_field;
gmac->regmap_field = devm_regmap_field_alloc(dev, regmap,
*gmac->emac_reg_field);
--
2.15.1
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