can: sun4i_can: Add acceptance register quirk

The Allwinner D1's CAN controllers have the ACPC and ACPM registers
moved down. Compensate for this by adding an offset quirk for the
acceptance registers.

Signed-off-by: John Watts <[email protected]>
Link: https://lore.kernel.org/all/[email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>

drivers/net/can/sun4i_can.c

@@ -205,9 +205,11 @@
  * struct sun4ican_quirks - Differences between SoC variants.
  *
  * @has_reset: SoC needs reset deasserted.
+ * @acp_offset: Offset of ACPC and ACPM registers
  */
 struct sun4ican_quirks {
 	bool has_reset;
+	int acp_offset;
 };
 
 struct sun4ican_priv {
@@ -216,6 +218,7 @@ struct sun4ican_priv {
 	struct clk *clk;
 	struct reset_control *reset;
 	spinlock_t cmdreg_lock;	/* lock for concurrent cmd register writes */
+	int acp_offset;
 };
 
 static const struct can_bittiming_const sun4ican_bittiming_const = {
@@ -338,8 +341,8 @@ static int sun4i_can_start(struct net_device *dev)
 	}
 
 	/* set filters - we accept all */
-	writel(0x00000000, priv->base + SUN4I_REG_ACPC_ADDR);
-	writel(0xFFFFFFFF, priv->base + SUN4I_REG_ACPM_ADDR);
+	writel(0x00000000, priv->base + SUN4I_REG_ACPC_ADDR + priv->acp_offset);
+	writel(0xFFFFFFFF, priv->base + SUN4I_REG_ACPM_ADDR + priv->acp_offset);
 
 	/* clear error counters and error code capture */
 	writel(0, priv->base + SUN4I_REG_ERRC_ADDR);
@@ -768,10 +771,12 @@ static const struct ethtool_ops sun4ican_ethtool_ops = {
 
 static const struct sun4ican_quirks sun4ican_quirks_a10 = {
 	.has_reset = false,
+	.acp_offset = 0,
 };
 
 static const struct sun4ican_quirks sun4ican_quirks_r40 = {
 	.has_reset = true,
+	.acp_offset = 0,
 };
 
 static const struct of_device_id sun4ican_of_match[] = {
@@ -870,6 +875,7 @@ static int sun4ican_probe(struct platform_device *pdev)
 	priv->base = addr;
 	priv->clk = clk;
 	priv->reset = reset;
+	priv->acp_offset = quirks->acp_offset;
 	spin_lock_init(&priv->cmdreg_lock);
 
 	platform_set_drvdata(pdev, dev);