[PATCH net-next v4 07/13] net: ethernet: oa_tc6: Add read_mms/write_mms register access functions

[Ciprian Regus via B4 Relay <devnull+ciprian.regus.analog.com@kernel.org>]

From: Ciprian Regus <ciprian.regus@analog.com>

The Open Alliance TC6 standard defines multiple memory maps for the
MAC-PHY's register space. These are used to separate standard, vendor
and PHY MMD specific registers. Define register access functions that
allow the caller to specify the MMS.

Signed-off-by: Ciprian Regus <ciprian.regus@analog.com>

---
v4 changelog:
 - changed the address parameter type to u16 from u32.
 - reworded the kdoc header for the new {read,write}_register_mms
   functions to better explain their use case.
v3 changelog:
 - replace the OA_TC6_MMS_REG() macro with the register access functions
   that allow passing an mms parameter.
v2 changelog:
 - New patch
---
 drivers/net/ethernet/oa_tc6.c | 44 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/oa_tc6.h        |  4 ++++
 2 files changed, 48 insertions(+)

diff --git a/drivers/net/ethernet/oa_tc6.c b/drivers/net/ethernet/oa_tc6.c
index 92da5bb74cc7..d32a1a323d48 100644
--- a/drivers/net/ethernet/oa_tc6.c
+++ b/drivers/net/ethernet/oa_tc6.c
@@ -61,6 +61,8 @@
 #define STATUS0_RESETC_POLL_DELAY		1000
 #define STATUS0_RESETC_POLL_TIMEOUT		1000000
 
+#define OA_TC6_REG_MMS_MASK		GENMASK(19, 16)
+
 /* Internal structure for MAC-PHY drivers */
 struct oa_tc6 {
 	struct device *dev;
@@ -344,6 +346,27 @@ int oa_tc6_read_register(struct oa_tc6 *tc6, u32 address, u32 *value)
 }
 EXPORT_SYMBOL_GPL(oa_tc6_read_register);
 
+/**
+ * oa_tc6_read_register_mms - function for reading a MAC-PHY register in a
+ * specified memory map.
+ * @tc6: oa_tc6 struct.
+ * @mms: Memory map selector for the register.
+ * @address: register address of the MAC-PHY to be read.
+ * @value: value read from the @address register address of the MAC-PHY.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int oa_tc6_read_register_mms(struct oa_tc6 *tc6, u8 mms, u16 address,
+			     u32 *value)
+{
+	u32 mms_reg;
+
+	mms_reg = FIELD_PREP(OA_TC6_REG_MMS_MASK, mms) | address;
+
+	return oa_tc6_read_registers(tc6, mms_reg, value, 1);
+}
+EXPORT_SYMBOL_GPL(oa_tc6_read_register_mms);
+
 /**
  * oa_tc6_write_registers - function for writing multiple consecutive registers.
  * @tc6: oa_tc6 struct.
@@ -388,6 +411,27 @@ int oa_tc6_write_register(struct oa_tc6 *tc6, u32 address, u32 value)
 }
 EXPORT_SYMBOL_GPL(oa_tc6_write_register);
 
+/**
+ * oa_tc6_write_register_mms - function for writing a MAC-PHY register in a
+ * specified memory map.
+ * @tc6: oa_tc6 struct.
+ * @mms: Memory map selector for the register.
+ * @address: register address of the MAC-PHY to be written.
+ * @value: value to be written in the @address register address of the MAC-PHY.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int oa_tc6_write_register_mms(struct oa_tc6 *tc6, u8 mms, u16 address,
+			      u32 value)
+{
+	u32 mms_reg;
+
+	mms_reg = FIELD_PREP(OA_TC6_REG_MMS_MASK, mms) | address;
+
+	return oa_tc6_write_registers(tc6, mms_reg, &value, 1);
+}
+EXPORT_SYMBOL_GPL(oa_tc6_write_register_mms);
+
 static int oa_tc6_check_phy_reg_direct_access_capability(struct oa_tc6 *tc6)
 {
 	u32 regval;
diff --git a/include/linux/oa_tc6.h b/include/linux/oa_tc6.h
index bd369aac9c3b..cace67cfc709 100644
--- a/include/linux/oa_tc6.h
+++ b/include/linux/oa_tc6.h
@@ -72,9 +72,13 @@ struct oa_tc6 *oa_tc6_init(struct spi_device *spi, struct net_device *netdev,
 			   struct oa_tc6_quirks *quirks);
 void oa_tc6_exit(struct oa_tc6 *tc6);
 int oa_tc6_write_register(struct oa_tc6 *tc6, u32 address, u32 value);
+int oa_tc6_write_register_mms(struct oa_tc6 *tc6, u8 mms, u16 address,
+			      u32 value);
 int oa_tc6_write_registers(struct oa_tc6 *tc6, u32 address, u32 value[],
 			   u8 length);
 int oa_tc6_read_register(struct oa_tc6 *tc6, u32 address, u32 *value);
+int oa_tc6_read_register_mms(struct oa_tc6 *tc6, u8 mms, u16 address,
+			     u32 *value);
 int oa_tc6_read_registers(struct oa_tc6 *tc6, u32 address, u32 value[],
 			  u8 length);
 netdev_tx_t oa_tc6_start_xmit(struct oa_tc6 *tc6, struct sk_buff *skb);

-- 
2.43.0