[PATCH 2/3] can: rockchip: add RK3588 CAN-FD support

[1579567540@qq.com]

From: luch00 <1579567540@qq.com>

Add support for the RK3588v2 CAN-FD controller by introducing a
dedicated model ID and OF match entry.

The block is closely related to the existing RK3568 variants, but it
cannot reuse their match data unchanged. In particular, RK3588v2
encodes RX_FIFO_CNT in bits 7:5 instead of 6:4, so the RX path needs
SoC-specific handling.

Validation on RK3588v2 also shows that its observed errata profile does
not fully match rk3568v2/rk3568v3, so keep a dedicated devtype for this
variant instead of relying on an rk3568 fallback.

Signed-off-by: luch00 <1579567540@qq.com>
---
 drivers/net/can/rockchip/rockchip_canfd-core.c | 14 ++++++++++++++
 drivers/net/can/rockchip/rockchip_canfd-rx.c   |  5 ++++-
 drivers/net/can/rockchip/rockchip_canfd.h      | 12 +++++++++++-
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/rockchip/rockchip_canfd-core.c b/drivers/net/can/rockchip/rockchip_canfd-core.c
index 29de0c01e..3c2480785 100644
--- a/drivers/net/can/rockchip/rockchip_canfd-core.c
+++ b/drivers/net/can/rockchip/rockchip_canfd-core.c
@@ -50,6 +50,15 @@ static const struct rkcanfd_devtype_data rkcanfd_devtype_data_rk3568v3 = {
 		RKCANFD_QUIRK_CANFD_BROKEN,
 };
 
+/* Tests on the rk3588v2 reproduce Erratum 5, but not
+ * Erratum 6 or the special CAN-FD frames that trigger Error Interrupts
+ * on rk3568v2/rk3568v3.
+ */
+static const struct rkcanfd_devtype_data rkcanfd_devtype_data_rk3588v2 = {
+	.model = RKCANFD_MODEL_RK3588V2,
+	.quirks = RKCANFD_QUIRK_RK3568_ERRATUM_5,
+};
+
 static const char *__rkcanfd_get_model_str(enum rkcanfd_model model)
 {
 	switch (model) {
@@ -57,6 +66,8 @@ static const char *__rkcanfd_get_model_str(enum rkcanfd_model model)
 		return "rk3568v2";
 	case RKCANFD_MODEL_RK3568V3:
 		return "rk3568v3";
+	case RKCANFD_MODEL_RK3588V2:
+		return "rk3588v2";
 	}
 
 	return "<unknown>";
@@ -846,6 +857,9 @@ static const struct of_device_id rkcanfd_of_match[] = {
 	}, {
 		.compatible = "rockchip,rk3568v3-canfd",
 		.data = &rkcanfd_devtype_data_rk3568v3,
+	}, {
+		.compatible = "rockchip,rk3588v2-canfd",
+		.data = &rkcanfd_devtype_data_rk3588v2,
 	}, {
 		/* sentinel */
 	},
diff --git a/drivers/net/can/rockchip/rockchip_canfd-rx.c b/drivers/net/can/rockchip/rockchip_canfd-rx.c
index 475c0409e..fe64db373 100644
--- a/drivers/net/can/rockchip/rockchip_canfd-rx.c
+++ b/drivers/net/can/rockchip/rockchip_canfd-rx.c
@@ -281,7 +281,10 @@ rkcanfd_rx_fifo_get_len(const struct rkcanfd_priv *priv)
 {
 	const u32 reg = rkcanfd_read(priv, RKCANFD_REG_RX_FIFO_CTRL);
 
-	return FIELD_GET(RKCANFD_REG_RX_FIFO_CTRL_RX_FIFO_CNT, reg);
+	if (priv->devtype_data.model == RKCANFD_MODEL_RK3588V2)
+		return FIELD_GET(RKCANFD_REG_RX_FIFO_CTRL_RX_FIFO_CNT_RK3588, reg);
+
+	return FIELD_GET(RKCANFD_REG_RX_FIFO_CTRL_RX_FIFO_CNT_RK3568, reg);
 }
 
 int rkcanfd_handle_rx_int(struct rkcanfd_priv *priv)
diff --git a/drivers/net/can/rockchip/rockchip_canfd.h b/drivers/net/can/rockchip/rockchip_canfd.h
index 93131c7d7..f6105b904 100644
--- a/drivers/net/can/rockchip/rockchip_canfd.h
+++ b/drivers/net/can/rockchip/rockchip_canfd.h
@@ -214,7 +214,8 @@
 #define RKCANFD_REG_TXEVENT_FIFO_CTRL_TXE_FIFO_ENABLE BIT(0)
 
 #define RKCANFD_REG_RX_FIFO_CTRL 0x118
-#define RKCANFD_REG_RX_FIFO_CTRL_RX_FIFO_CNT GENMASK(6, 4)
+#define RKCANFD_REG_RX_FIFO_CTRL_RX_FIFO_CNT_RK3568 GENMASK(6, 4)
+#define RKCANFD_REG_RX_FIFO_CTRL_RX_FIFO_CNT_RK3588 GENMASK(7, 5)
 #define RKCANFD_REG_RX_FIFO_CTRL_RX_FIFO_FULL_WATERMARK GENMASK(3, 1)
 #define RKCANFD_REG_RX_FIFO_CTRL_RX_FIFO_ENABLE BIT(0)
 
@@ -331,6 +332,11 @@
  * rarely with the standard clock of 300 MHz, but almost immediately
  * at 80 MHz.
  *
+ * Test on the rk3588v2 shows the same empty FIFO condition.
+ * In that setup rx_fifo_empty_errors increments when the bus
+ * transitions from idle to high CAN-FD load and stops growing once
+ * the bus reaches a steady state.
+ *
  * To workaround this problem, check for empty FIFO with
  * rkcanfd_fifo_header_empty() in rkcanfd_handle_rx_int_one() and exit
  * early.
@@ -424,6 +430,9 @@
  *     cansequence -rv -i 1
  *
  * - TX starvation after repeated Bus-Off
+ *   Tests on the rk3588v2 show the same problem. In a
+ *   10-cycle Bus-Off recovery test, 9 cycles failed to send after the
+ *   controller restarted.
  *   To reproduce:
  *   host:
  *     sleep 3 && cangen can0 -I2 -Li -Di -p10 -g 0.0
@@ -434,6 +443,7 @@
 enum rkcanfd_model {
 	RKCANFD_MODEL_RK3568V2 = 0x35682,
 	RKCANFD_MODEL_RK3568V3 = 0x35683,
+	RKCANFD_MODEL_RK3588V2 = 0x35882,
 };
 
 struct rkcanfd_devtype_data {
-- 
2.34.1