[PATCH net-next 2/4] mv88e6xxx: Cache scratch config3 of 6352

[Fidan Aliyeva <fidan.aliyeva.ext@ericsson.com>]

Changes:

1. Add g2_scratch_config3 member to mv88e6xxx_chip.

2. Add mv88e6352_g2_cache_global_scratch_config3  which reads the
CONFIG3 value from the scratch register and caches it.

3. Call this function in mv88e6352_reset.

Co-developed-by: Thomas Eckerman <thomas.eckerman.ext@ericsson.com>
Signed-off-by: Thomas Eckerman <thomas.eckerman.ext@ericsson.com>
Signed-off-by: Fidan Aliyeva <fidan.aliyeva.ext@ericsson.com>
---
 drivers/net/dsa/mv88e6xxx/chip.c            |  7 +++++-
 drivers/net/dsa/mv88e6xxx/chip.h            |  3 +++
 drivers/net/dsa/mv88e6xxx/global2.h         |  1 +
 drivers/net/dsa/mv88e6xxx/global2_scratch.c | 25 +++++++++++++++++++++
 4 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 6102b7fd8d44..4ed6f880e02c 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -3736,13 +3736,18 @@ static int mv88e6390_setup_errata(struct mv88e6xxx_chip *chip)
 	return mv88e6xxx_software_reset(chip);
 }

+/* For MV88E6XXX_FAMILY_6352, perform reset on G1 control.
+ * Also, read and cache G2 scratch register.
+ */
 static int mv88e6352_reset(struct mv88e6xxx_chip *chip)
 {
 	int err;

 	err = mv88e6352_g1_reset(chip);
+	if (err)
+		return err;

-	return err;
+	return mv88e6352_g2_cache_global_scratch_config3(chip);
 }

 /* prod_id for switch families which do not have a PHY model number */
diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h
index 2b235ac2c5df..d911f60aca10 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.h
+++ b/drivers/net/dsa/mv88e6xxx/chip.h
@@ -454,6 +454,9 @@ struct mv88e6xxx_chip {

 	/* TCAM entries */
 	struct mv88e6xxx_tcam tcam;
+
+	/* Global2 scratch register config data3 */
+	u8 g2_scratch_config3;
 };

 #define TCAM_MATCH_SIZE 96
diff --git a/drivers/net/dsa/mv88e6xxx/global2.h b/drivers/net/dsa/mv88e6xxx/global2.h
index 82f9b410de0b..ff5adf7c9bc3 100644
--- a/drivers/net/dsa/mv88e6xxx/global2.h
+++ b/drivers/net/dsa/mv88e6xxx/global2.h
@@ -382,6 +382,7 @@ int mv88e6390_g2_scratch_gpio_set_smi(struct mv88e6xxx_chip *chip,
 				      bool external);
 int mv88e6393x_g2_scratch_gpio_set_smi(struct mv88e6xxx_chip *chip,
 				       bool external);
+int mv88e6352_g2_cache_global_scratch_config3(struct mv88e6xxx_chip *chip);
 int mv88e6352_g2_scratch_port_has_serdes(struct mv88e6xxx_chip *chip, int port);
 int mv88e6xxx_g2_atu_stats_set(struct mv88e6xxx_chip *chip, u16 kind, u16 bin);
 int mv88e6xxx_g2_atu_stats_get(struct mv88e6xxx_chip *chip, u16 *stats);
diff --git a/drivers/net/dsa/mv88e6xxx/global2_scratch.c b/drivers/net/dsa/mv88e6xxx/global2_scratch.c
index 53a6d3ed63b3..a2c09bbdde17 100644
--- a/drivers/net/dsa/mv88e6xxx/global2_scratch.c
+++ b/drivers/net/dsa/mv88e6xxx/global2_scratch.c
@@ -321,6 +321,31 @@ int mv88e6393x_g2_scratch_gpio_set_smi(struct mv88e6xxx_chip *chip,
 	return mv88e6xxx_g2_scratch_write(chip, misc_cfg, val);
 }

+/**
+ * mv88e6352_g2_cache_global_scratch_config3 - caches G2 CONFIG3 value
+ * @chip: chip private data
+ *
+ * Reads and stores config3 value of global2 scratch registers, which
+ * can be used to determine if the port is attached to a serdes. The
+ * value does not change once the switch is released from reset and
+ * represents the value of the pin strapping. Returns negative error
+ * number if the register read fails; otherwise, 0
+ */
+int mv88e6352_g2_cache_global_scratch_config3(struct mv88e6xxx_chip *chip)
+{
+	u8 config3;
+	int err;
+
+	err = mv88e6xxx_g2_scratch_read(chip, MV88E6352_G2_SCRATCH_CONFIG_DATA3,
+					&config3);
+	if (err)
+		return err;
+
+	chip->g2_scratch_config3 = config3;
+
+	return 0;
+}
+
 /**
  * mv88e6352_g2_scratch_port_has_serdes - indicate if a port can have a serdes
  * @chip: chip private data
--
2.36.0