1 files changed, 70 insertions, 0 deletions
diff --git a/drivers/net/dsa/mv88e6xxx/port_hidden.c b/drivers/net/dsa/mv88e6xxx/port_hidden.c
new file mode 100644
index 000000000000..b49d05f0e117
--- /dev/null
+++ b/drivers/net/dsa/mv88e6xxx/port_hidden.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Marvell 88E6xxx Switch Hidden Registers support
+ *
+ * Copyright (c) 2008 Marvell Semiconductor
+ *
+ * Copyright (c) 2019 Andrew Lunn <andrew@lunn.ch>
+ */
+
+#include <linux/bitfield.h>
+
+#include "chip.h"
+#include "port.h"
+
+/* The mv88e6390 and mv88e6341 have some hidden registers used for debug and
+ * development. The errata also makes use of them.
+ */
+int mv88e6xxx_port_hidden_write(struct mv88e6xxx_chip *chip, int block,
+				int port, int reg, u16 val)
+{
+	u16 ctrl;
+	int err;
+
+	err = mv88e6xxx_port_write(chip, MV88E6XXX_PORT_RESERVED_1A_DATA_PORT,
+				   MV88E6XXX_PORT_RESERVED_1A, val);
+	if (err)
+		return err;
+
+	ctrl = MV88E6XXX_PORT_RESERVED_1A_BUSY |
+	       MV88E6XXX_PORT_RESERVED_1A_WRITE |
+	       block << MV88E6XXX_PORT_RESERVED_1A_BLOCK_SHIFT |
+	       port << MV88E6XXX_PORT_RESERVED_1A_PORT_SHIFT |
+	       reg;
+
+	return mv88e6xxx_port_write(chip, MV88E6XXX_PORT_RESERVED_1A_CTRL_PORT,
+				    MV88E6XXX_PORT_RESERVED_1A, ctrl);
+}
+
+int mv88e6xxx_port_hidden_wait(struct mv88e6xxx_chip *chip)
+{
+	int bit = __bf_shf(MV88E6XXX_PORT_RESERVED_1A_BUSY);
+
+	return mv88e6xxx_wait_bit(chip, MV88E6XXX_PORT_RESERVED_1A_CTRL_PORT,
+				  MV88E6XXX_PORT_RESERVED_1A, bit, 0);
+}
+
+int mv88e6xxx_port_hidden_read(struct mv88e6xxx_chip *chip, int block, int port,
+			       int reg, u16 *val)
+{
+	u16 ctrl;
+	int err;
+
+	ctrl = MV88E6XXX_PORT_RESERVED_1A_BUSY |
+	       MV88E6XXX_PORT_RESERVED_1A_READ |
+	       block << MV88E6XXX_PORT_RESERVED_1A_BLOCK_SHIFT |
+	       port << MV88E6XXX_PORT_RESERVED_1A_PORT_SHIFT |
+	       reg;
+
+	err = mv88e6xxx_port_write(chip, MV88E6XXX_PORT_RESERVED_1A_CTRL_PORT,
+				   MV88E6XXX_PORT_RESERVED_1A, ctrl);
+	if (err)
+		return err;
+
+	err = mv88e6xxx_port_hidden_wait(chip);
+	if (err)
+		return err;
+
+	return mv88e6xxx_port_read(chip, MV88E6XXX_PORT_RESERVED_1A_DATA_PORT,
+				   MV88E6XXX_PORT_RESERVED_1A, val);
+}