Subject: [PATCH v4 net-next 1/2] amd-xgbe: reorganize the code of XPCS access

From: Raju Rangoju <[email-masked]>
Date: Tue, 6 Feb 2024 02:18:59 +0530

The xgbe_{read/write}_mmd_regs_v* functions have common code which can
be moved to helper functions. Also, the xgbe_pci_probe() needs
reorganization.

Add new helper functions to calculate the mmd_address for v1/v2 of xpcs
access. And, convert if/else statements in xgbe_pci_probe() to switch
case. This helps code look cleaner.

Signed-off-by: Raju Rangoju <[email-masked]>
---
 drivers/net/ethernet/amd/xgbe/xgbe-dev.c | 62 ++++++++++--------------
 drivers/net/ethernet/amd/xgbe/xgbe-pci.c | 35 +++++++------
 drivers/net/ethernet/amd/xgbe/xgbe.h     |  4 ++
 3 files changed, 51 insertions(+), 50 deletions(-)

diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
index f393228d41c7..ac70db54c92a 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
@@ -1150,18 +1150,16 @@ static int xgbe_set_gpio(struct xgbe_prv_data *pdata, unsigned int gpio)
 	return 0;
 }
 
-static int xgbe_read_mmd_regs_v2(struct xgbe_prv_data *pdata, int prtad,
-				 int mmd_reg)
+static unsigned int get_mmd_address(struct xgbe_prv_data *pdata, int mmd_reg)
 {
-	unsigned long flags;
-	unsigned int mmd_address, index, offset;
-	int mmd_data;
-
-	if (mmd_reg & XGBE_ADDR_C45)
-		mmd_address = mmd_reg & ~XGBE_ADDR_C45;
-	else
-		mmd_address = (pdata->mdio_mmd << 16) | (mmd_reg & 0xffff);
+	return (mmd_reg & XGBE_ADDR_C45) ?
+		mmd_reg & ~XGBE_ADDR_C45 :
+		(pdata->mdio_mmd << 16) | (mmd_reg & 0xffff);
+}
 
+static void get_pcs_index_and_offset(struct xgbe_prv_data *pdata, unsigned int mmd_address,
+				     unsigned int *index, unsigned int *offset)
+{
 	/* The PCS registers are accessed using mmio. The underlying
 	 * management interface uses indirect addressing to access the MMD
 	 * register sets. This requires accessing of the PCS register in two
@@ -1172,8 +1170,20 @@ static int xgbe_read_mmd_regs_v2(struct xgbe_prv_data *pdata, int prtad,
 	 * offset 1 bit and reading 16 bits of data.
 	 */
 	mmd_address <<= 1;
-	index = mmd_address & ~pdata->xpcs_window_mask;
-	offset = pdata->xpcs_window + (mmd_address & pdata->xpcs_window_mask);
+	*index = mmd_address & ~pdata->xpcs_window_mask;
+	*offset = pdata->xpcs_window + (mmd_address & pdata->xpcs_window_mask);
+}
+
+static int xgbe_read_mmd_regs_v2(struct xgbe_prv_data *pdata, int prtad,
+				 int mmd_reg)
+{
+	unsigned long flags;
+	unsigned int mmd_address, index, offset;
+	int mmd_data;
+
+	mmd_address = get_mmd_address(pdata, mmd_reg);
+
+	get_pcs_index_and_offset(pdata, mmd_address, &index, &offset);
 
 	spin_lock_irqsave(&pdata->xpcs_lock, flags);
 	XPCS32_IOWRITE(pdata, pdata->xpcs_window_sel_reg, index);
@@ -1189,23 +1199,9 @@ static void xgbe_write_mmd_regs_v2(struct xgbe_prv_data *pdata, int prtad,
 	unsigned long flags;
 	unsigned int mmd_address, index, offset;
 
-	if (mmd_reg & XGBE_ADDR_C45)
-		mmd_address = mmd_reg & ~XGBE_ADDR_C45;
-	else
-		mmd_address = (pdata->mdio_mmd << 16) | (mmd_reg & 0xffff);
+	mmd_address = get_mmd_address(pdata, mmd_reg);
 
-	/* The PCS registers are accessed using mmio. The underlying
-	 * management interface uses indirect addressing to access the MMD
-	 * register sets. This requires accessing of the PCS register in two
-	 * phases, an address phase and a data phase.
-	 *
-	 * The mmio interface is based on 16-bit offsets and values. All
-	 * register offsets must therefore be adjusted by left shifting the
-	 * offset 1 bit and writing 16 bits of data.
-	 */
-	mmd_address <<= 1;
-	index = mmd_address & ~pdata->xpcs_window_mask;
-	offset = pdata->xpcs_window + (mmd_address & pdata->xpcs_window_mask);
+	get_pcs_index_and_offset(pdata, mmd_address, &index, &offset);
 
 	spin_lock_irqsave(&pdata->xpcs_lock, flags);
 	XPCS32_IOWRITE(pdata, pdata->xpcs_window_sel_reg, index);
@@ -1220,10 +1216,7 @@ static int xgbe_read_mmd_regs_v1(struct xgbe_prv_data *pdata, int prtad,
 	unsigned int mmd_address;
 	int mmd_data;
 
-	if (mmd_reg & XGBE_ADDR_C45)
-		mmd_address = mmd_reg & ~XGBE_ADDR_C45;
-	else
-		mmd_address = (pdata->mdio_mmd << 16) | (mmd_reg & 0xffff);
+	mmd_address = get_mmd_address(pdata, mmd_reg);
 
 	/* The PCS registers are accessed using mmio. The underlying APB3
 	 * management interface uses indirect addressing to access the MMD
@@ -1248,10 +1241,7 @@ static void xgbe_write_mmd_regs_v1(struct xgbe_prv_data *pdata, int prtad,
 	unsigned int mmd_address;
 	unsigned long flags;
 
-	if (mmd_reg & XGBE_ADDR_C45)
-		mmd_address = mmd_reg & ~XGBE_ADDR_C45;
-	else
-		mmd_address = (pdata->mdio_mmd << 16) | (mmd_reg & 0xffff);
+	mmd_address = get_mmd_address(pdata, mmd_reg);
 
 	/* The PCS registers are accessed using mmio. The underlying APB3
 	 * management interface uses indirect addressing to access the MMD
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-pci.c b/drivers/net/ethernet/amd/xgbe/xgbe-pci.c
index f409d7bd1f1e..18d1cc16c919 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-pci.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-pci.c
@@ -274,20 +274,27 @@ static int xgbe_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
 	/* Set the PCS indirect addressing definition registers */
 	rdev = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0, 0));
-	if (rdev &&
-	    (rdev->vendor == PCI_VENDOR_ID_AMD) && (rdev->device == 0x15d0)) {
-		pdata->xpcs_window_def_reg = PCS_V2_RV_WINDOW_DEF;
-		pdata->xpcs_window_sel_reg = PCS_V2_RV_WINDOW_SELECT;
-	} else if (rdev && (rdev->vendor == PCI_VENDOR_ID_AMD) &&
-		   (rdev->device == 0x14b5)) {
-		pdata->xpcs_window_def_reg = PCS_V2_YC_WINDOW_DEF;
-		pdata->xpcs_window_sel_reg = PCS_V2_YC_WINDOW_SELECT;
-
-		/* Yellow Carp devices do not need cdr workaround */
-		pdata->vdata->an_cdr_workaround = 0;
-
-		/* Yellow Carp devices do not need rrc */
-		pdata->vdata->enable_rrc = 0;
+	if (rdev && rdev->vendor == PCI_VENDOR_ID_AMD) {
+		switch (rdev->device) {
+		case XGBE_RV_PCI_DEVICE_ID:
+			pdata->xpcs_window_def_reg = PCS_V2_RV_WINDOW_DEF;
+			pdata->xpcs_window_sel_reg = PCS_V2_RV_WINDOW_SELECT;
+			break;
+		case XGBE_YC_PCI_DEVICE_ID:
+			pdata->xpcs_window_def_reg = PCS_V2_YC_WINDOW_DEF;
+			pdata->xpcs_window_sel_reg = PCS_V2_YC_WINDOW_SELECT;
+
+			/* Yellow Carp devices do not need cdr workaround */
+			pdata->vdata->an_cdr_workaround = 0;
+
+			/* Yellow Carp devices do not need rrc */
+			pdata->vdata->enable_rrc = 0;
+			break;
+		default:
+			pdata->xpcs_window_def_reg = PCS_V2_WINDOW_DEF;
+			pdata->xpcs_window_sel_reg = PCS_V2_WINDOW_SELECT;
+			break;
+		}
 	} else {
 		pdata->xpcs_window_def_reg = PCS_V2_WINDOW_DEF;
 		pdata->xpcs_window_sel_reg = PCS_V2_WINDOW_SELECT;
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe.h b/drivers/net/ethernet/amd/xgbe/xgbe.h
index ad136ed493ed..c9f644ecb1b5 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe.h
+++ b/drivers/net/ethernet/amd/xgbe/xgbe.h
@@ -347,6 +347,10 @@
 		    (_src)->link_modes._sname,		\
 		    __ETHTOOL_LINK_MODE_MASK_NBITS)
 
+/* XGBE PCI device id */
+#define XGBE_RV_PCI_DEVICE_ID	0x15d0
+#define XGBE_YC_PCI_DEVICE_ID	0x14b5
+
 struct xgbe_prv_data;
 
 struct xgbe_packet_data {
-- 
2.34.1