sxgbe: remove unused code

From: Jean Sacren <[email protected]>

With the introduction of this commit 1edb9ca69e8a
("net: sxgbe: add basic framework for Samsung 10Gb ethernet driver"), the following interface was added:

	int sxgbe_xpcs_init(struct net_device *ndev);
	int sxgbe_xpcs_init_1G(struct net_device *ndev);

But those two functions have never been used since the inception.

In addition to the interface, the following macros are defined in sxgbe_xpcs header but not used:

SR_MII_MMD_AN_ADV
SR_MII_MMD_AN_LINK_PARTNER_BA
VR_MII_MMD_AN_CONTROL
VR_MII_MMD_AN_INT_STATUS
XPCS_TYPE_SEL_R
XPCS_TYPE_SEL_W
XPCS_RXAUI_MODE

If we remove the interface, functions it uses and all other macros defined in sxgbe_xpcs header will also become useless. Thus, the whole sxgbe_xpcs shebang should be all gone.

Julia Lawall observed:

"... I was looking at dependencies between networking files. This one stands out because nothing is dependent[ ]on it, even the files it is compiled with, and it doesn't contain the usual functions, register_netdev, etc."

David Miller commented:

"There are no in-tree callers of this code. It should be removed until there are in-tree users.

Nobody can figure out if the interface for this is done properly without seeing the call sites and how they work. It is therefore impossible to review this code and judge it[']s design."

Let's remove this unused code. As a matter of fact, it should not have been merged in the first place.

Reported-by Julia Lawall <[email protected]>

Signed-off-by Jean Sacren <[email protected]>

Cc Byungho An <[email protected]>

Cc Girish K S <[email protected]>

---
We may use "--ignore FILE_PATH_CHANGES" to suppress checkpatch warning.

 drivers/net/ethernet/samsung/sxgbe/Makefile     |  2 +-
 drivers/net/ethernet/samsung/sxgbe/sxgbe_xpcs.c | 91 -------------------------
 drivers/net/ethernet/samsung/sxgbe/sxgbe_xpcs.h | 38 -----------
 3 files changed, 1 insertion(+), 130 deletions(-)
 delete mode 100644 drivers/net/ethernet/samsung/sxgbe/sxgbe_xpcs.c
 delete mode 100644 drivers/net/ethernet/samsung/sxgbe/sxgbe_xpcs.h

drivers/net/ethernet/samsung/sxgbe/Makefile +1 -1

index dcc80b9d4370..31e968561d5c 100644
@@ -1,4 +1,4 @@
 obj-$(CONFIG_SXGBE_ETH) += samsung-sxgbe.o
 samsung-sxgbe-objs:= sxgbe_platform.o sxgbe_main.o sxgbe_desc.o \
 		sxgbe_dma.o sxgbe_core.o sxgbe_mtl.o  sxgbe_mdio.o \
-		sxgbe_ethtool.o sxgbe_xpcs.o $(samsung-sxgbe-y)
+		sxgbe_ethtool.o $(samsung-sxgbe-y)

drivers/net/ethernet/samsung/sxgbe/sxgbe_xpcs.c deleted +0 -91

deleted file mode 100644
index 51c32194ba88..000000000000
@@ -1,91 +0,0 @@
-/* 10G controller driver for Samsung SoCs
- *
- * Copyright (C) 2013 Samsung Electronics Co., Ltd.
- *		http://www.samsung.com
- *
- * Author: Siva Reddy Kallam <[email protected]>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-#include <linux/bitops.h>
-#include <linux/kernel.h>
-#include <linux/netdevice.h>
-#include <linux/phy.h>
-#include "sxgbe_common.h"
-#include "sxgbe_xpcs.h"
-
-static int sxgbe_xpcs_read(struct net_device *ndev, unsigned int reg)
-{
-	u32 value;
-	struct sxgbe_priv_data *priv = netdev_priv(ndev);
-
-	value = readl(priv->ioaddr + XPCS_OFFSET + reg);
-
-	return value;
-}
-
-static int sxgbe_xpcs_write(struct net_device *ndev, int reg, int data)
-{
-	struct sxgbe_priv_data *priv = netdev_priv(ndev);
-
-	writel(data, priv->ioaddr + XPCS_OFFSET + reg);
-
-	return 0;
-}
-
-int sxgbe_xpcs_init(struct net_device *ndev)
-{
-	u32 value;
-
-	value = sxgbe_xpcs_read(ndev, SR_PCS_MMD_CONTROL1);
-	/* 10G XAUI mode */
-	sxgbe_xpcs_write(ndev, SR_PCS_CONTROL2, XPCS_TYPE_SEL_X);
-	sxgbe_xpcs_write(ndev, VR_PCS_MMD_XAUI_MODE_CONTROL, XPCS_XAUI_MODE);
-	sxgbe_xpcs_write(ndev, VR_PCS_MMD_XAUI_MODE_CONTROL, value | BIT(13));
-	sxgbe_xpcs_write(ndev, SR_PCS_MMD_CONTROL1, value | BIT(11));
-
-	do {
-		value = sxgbe_xpcs_read(ndev, VR_PCS_MMD_DIGITAL_STATUS);
-	} while ((value & XPCS_QSEQ_STATE_MPLLOFF) == XPCS_QSEQ_STATE_STABLE);
-
-	value = sxgbe_xpcs_read(ndev, SR_PCS_MMD_CONTROL1);
-	sxgbe_xpcs_write(ndev, SR_PCS_MMD_CONTROL1, value & ~BIT(11));
-
-	do {
-		value = sxgbe_xpcs_read(ndev, VR_PCS_MMD_DIGITAL_STATUS);
-	} while ((value & XPCS_QSEQ_STATE_MPLLOFF) != XPCS_QSEQ_STATE_STABLE);
-
-	return 0;
-}
-
-int sxgbe_xpcs_init_1G(struct net_device *ndev)
-{
-	int value;
-
-	/* 10GBASE-X PCS (1G) mode */
-	sxgbe_xpcs_write(ndev, SR_PCS_CONTROL2, XPCS_TYPE_SEL_X);
-	sxgbe_xpcs_write(ndev, VR_PCS_MMD_XAUI_MODE_CONTROL, XPCS_XAUI_MODE);
-	value = sxgbe_xpcs_read(ndev, SR_PCS_MMD_CONTROL1);
-	sxgbe_xpcs_write(ndev, SR_PCS_MMD_CONTROL1, value & ~BIT(13));
-
-	value = sxgbe_xpcs_read(ndev, SR_MII_MMD_CONTROL);
-	sxgbe_xpcs_write(ndev, SR_MII_MMD_CONTROL, value | BIT(6));
-	sxgbe_xpcs_write(ndev, SR_MII_MMD_CONTROL, value & ~BIT(13));
-	value = sxgbe_xpcs_read(ndev, SR_PCS_MMD_CONTROL1);
-	sxgbe_xpcs_write(ndev, SR_PCS_MMD_CONTROL1, value | BIT(11));
-
-	do {
-		value = sxgbe_xpcs_read(ndev, VR_PCS_MMD_DIGITAL_STATUS);
-	} while ((value & XPCS_QSEQ_STATE_MPLLOFF) != XPCS_QSEQ_STATE_STABLE);
-
-	value = sxgbe_xpcs_read(ndev, SR_PCS_MMD_CONTROL1);
-	sxgbe_xpcs_write(ndev, SR_PCS_MMD_CONTROL1, value & ~BIT(11));
-
-	/* Auto Negotiation cluase 37 enable */
-	value = sxgbe_xpcs_read(ndev, SR_MII_MMD_CONTROL);
-	sxgbe_xpcs_write(ndev, SR_MII_MMD_CONTROL, value | BIT(12));
-
-	return 0;
-}

drivers/net/ethernet/samsung/sxgbe/sxgbe_xpcs.h deleted +0 -38

deleted file mode 100644
index 6b26a50724d3..000000000000
@@ -1,38 +0,0 @@
-/* 10G controller driver for Samsung SoCs
- *
- * Copyright (C) 2013 Samsung Electronics Co., Ltd.
- *		http://www.samsung.com
- *
- * Author: Byungho An <[email protected]>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-#ifndef __SXGBE_XPCS_H__
-#define __SXGBE_XPCS_H__
-
-/* XPCS Registers */
-#define XPCS_OFFSET			0x1A060000
-#define SR_PCS_MMD_CONTROL1		0x030000
-#define SR_PCS_CONTROL2			0x030007
-#define VR_PCS_MMD_XAUI_MODE_CONTROL	0x038004
-#define VR_PCS_MMD_DIGITAL_STATUS	0x038010
-#define SR_MII_MMD_CONTROL		0x1F0000
-#define SR_MII_MMD_AN_ADV		0x1F0004
-#define SR_MII_MMD_AN_LINK_PARTNER_BA	0x1F0005
-#define VR_MII_MMD_AN_CONTROL		0x1F8001
-#define VR_MII_MMD_AN_INT_STATUS	0x1F8002
-
-#define XPCS_QSEQ_STATE_STABLE		0x10
-#define XPCS_QSEQ_STATE_MPLLOFF		0x1c
-#define XPCS_TYPE_SEL_R			0x00
-#define XPCS_TYPE_SEL_X			0x01
-#define XPCS_TYPE_SEL_W			0x02
-#define XPCS_XAUI_MODE			0x00
-#define XPCS_RXAUI_MODE			0x01
-
-int sxgbe_xpcs_init(struct net_device *ndev);
-int sxgbe_xpcs_init_1G(struct net_device *ndev);
-
-#endif /* __SXGBE_XPCS_H__ */

From: Jean Sacren <[email protected]>

Remove the unused code of sxgbe_xpcs.

Reported-by Julia Lawall <[email protected]>

Suggested-by David S. Miller <[email protected]>

Signed-off-by Jean Sacren <[email protected]>

Cc Byungho An <[email protected]>

Cc Girish K S <[email protected]>

Link http://lkml.kernel.org/r/alpine.DEB.2.10.1601191918470.2531@hadrien open here