net: pcs: xpcs: add support for NXP SJA1105

The NXP SJA1105 DSA switch integrates a Synopsys SGMII XPCS on port 4.
The generic code works fine, except there is an integration issue which
needs to be dealt with: in this switch, the XPCS is integrated with a
PMA that has the TX lane polarity inverted by default (PLUS is MINUS,
MINUS is PLUS).

To obtain normal non-inverted behavior, the TX lane polarity must be
inverted in the PCS, via the DIGITAL_CONTROL_2 register.

We introduce a pma_config() method in xpcs_compat which is called by the
phylink_pcs_config() implementation.

Also, the NXP SJA1105 returns all zeroes in the PHY ID registers 2 and 3.
We need to hack up an ad-hoc PHY ID (OUI is zero, device ID is 1) in
order for the XPCS driver to recognize it. This PHY ID is added to the
public include/linux/pcs/pcs-xpcs.h for that reason (for the sja1105
driver to be able to use it in a later patch).

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Vladimir Oltean 2021-06-11 23:05:25 +03:00 committed by David S. Miller
parent 36641b045c
commit dd0721ea4c
6 changed files with 55 additions and 3 deletions

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@ -13203,6 +13203,7 @@ M: Vladimir Oltean <olteanv@gmail.com>
L: linux-kernel@vger.kernel.org
S: Maintained
F: drivers/net/dsa/sja1105
F: drivers/net/pcs/pcs-xpcs-nxp.c
NXP TDA998X DRM DRIVER
M: Russell King <linux@armlinux.org.uk>

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@ -1,5 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
# Makefile for Linux PCS drivers
obj-$(CONFIG_PCS_XPCS) += pcs-xpcs.o
pcs_xpcs-$(CONFIG_PCS_XPCS) := pcs-xpcs.o pcs-xpcs-nxp.o
obj-$(CONFIG_PCS_XPCS) += pcs_xpcs.o
obj-$(CONFIG_PCS_LYNX) += pcs-lynx.o

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@ -0,0 +1,16 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright 2021 NXP Semiconductors
*/
#include <linux/pcs/pcs-xpcs.h>
#include "pcs-xpcs.h"
/* In NXP SJA1105, the PCS is integrated with a PMA that has the TX lane
* polarity inverted by default (PLUS is MINUS, MINUS is PLUS). To obtain
* normal non-inverted behavior, the TX lane polarity must be inverted in the
* PCS, via the DIGITAL_CONTROL_2 register.
*/
int nxp_sja1105_sgmii_pma_config(struct dw_xpcs *xpcs)
{
return xpcs_write(xpcs, MDIO_MMD_VEND2, DW_VR_MII_DIG_CTRL2,
DW_VR_MII_DIG_CTRL2_TX_POL_INV);
}

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@ -117,6 +117,7 @@ struct xpcs_compat {
const phy_interface_t *interface;
int num_interfaces;
int an_mode;
int (*pma_config)(struct dw_xpcs *xpcs);
};
struct xpcs_id {
@ -168,7 +169,7 @@ static bool __xpcs_linkmode_supported(const struct xpcs_compat *compat,
#define xpcs_linkmode_supported(compat, mode) \
__xpcs_linkmode_supported(compat, ETHTOOL_LINK_MODE_ ## mode ## _BIT)
static int xpcs_read(struct dw_xpcs *xpcs, int dev, u32 reg)
int xpcs_read(struct dw_xpcs *xpcs, int dev, u32 reg)
{
u32 reg_addr = mdiobus_c45_addr(dev, reg);
struct mii_bus *bus = xpcs->mdiodev->bus;
@ -177,7 +178,7 @@ static int xpcs_read(struct dw_xpcs *xpcs, int dev, u32 reg)
return mdiobus_read(bus, addr, reg_addr);
}
static int xpcs_write(struct dw_xpcs *xpcs, int dev, u32 reg, u16 val)
int xpcs_write(struct dw_xpcs *xpcs, int dev, u32 reg, u16 val)
{
u32 reg_addr = mdiobus_c45_addr(dev, reg);
struct mii_bus *bus = xpcs->mdiodev->bus;
@ -788,6 +789,12 @@ static int xpcs_do_config(struct dw_xpcs *xpcs, phy_interface_t interface,
return -1;
}
if (compat->pma_config) {
ret = compat->pma_config(xpcs);
if (ret)
return ret;
}
return 0;
}
@ -1022,11 +1029,25 @@ static const struct xpcs_compat synopsys_xpcs_compat[DW_XPCS_INTERFACE_MAX] = {
},
};
static const struct xpcs_compat nxp_sja1105_xpcs_compat[DW_XPCS_INTERFACE_MAX] = {
[DW_XPCS_SGMII] = {
.supported = xpcs_sgmii_features,
.interface = xpcs_sgmii_interfaces,
.num_interfaces = ARRAY_SIZE(xpcs_sgmii_interfaces),
.an_mode = DW_AN_C37_SGMII,
.pma_config = nxp_sja1105_sgmii_pma_config,
},
};
static const struct xpcs_id xpcs_id_list[] = {
{
.id = SYNOPSYS_XPCS_ID,
.mask = SYNOPSYS_XPCS_MASK,
.compat = synopsys_xpcs_compat,
}, {
.id = NXP_SJA1105_XPCS_ID,
.mask = SYNOPSYS_XPCS_MASK,
.compat = nxp_sja1105_xpcs_compat,
},
};

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@ -60,10 +60,15 @@
/* EEE Mode Control Register */
#define DW_VR_MII_EEE_MCTRL0 0x8006
#define DW_VR_MII_EEE_MCTRL1 0x800b
#define DW_VR_MII_DIG_CTRL2 0x80e1
/* VR_MII_DIG_CTRL1 */
#define DW_VR_MII_DIG_CTRL1_MAC_AUTO_SW BIT(9)
/* VR_MII_DIG_CTRL2 */
#define DW_VR_MII_DIG_CTRL2_TX_POL_INV BIT(4)
#define DW_VR_MII_DIG_CTRL2_RX_POL_INV BIT(0)
/* VR_MII_AN_CTRL */
#define DW_VR_MII_AN_CTRL_TX_CONFIG_SHIFT 3
#define DW_VR_MII_TX_CONFIG_MASK BIT(3)
@ -101,3 +106,8 @@
/* VR MII EEE Control 1 defines */
#define DW_VR_MII_EEE_TRN_LPI BIT(0) /* Transparent Mode Enable */
int xpcs_read(struct dw_xpcs *xpcs, int dev, u32 reg);
int xpcs_write(struct dw_xpcs *xpcs, int dev, u32 reg, u16 val);
int nxp_sja1105_sgmii_pma_config(struct dw_xpcs *xpcs);

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@ -10,6 +10,8 @@
#include <linux/phy.h>
#include <linux/phylink.h>
#define NXP_SJA1105_XPCS_ID 0x00000010
/* AN mode */
#define DW_AN_C73 1
#define DW_AN_C37_SGMII 2