[PATCH v2 net-next 4/4] drivers/net/phy: add driver for the onsemi NCN26000 10BASE-T1S PHY

Piergiorgio Beruto
2022-12-05T01:43:24Z

Add support for the onsemi NCN26000 10BASE-T1S industrial Ethernet PHY.
The driver supports Point-to-Multipoint operation without
auto-negotiation and with link control handling. The PLCA RS support
will be included on a separate patch.

Signed-off-by: Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
---
MAINTAINERS | 8 ++
drivers/net/phy/Kconfig | 7 +
drivers/net/phy/Makefile | 1 +
drivers/net/phy/mdio-open-alliance.h | 44 +++++++
drivers/net/phy/ncn26000.c | 187 +++++++++++++++++++++++++++
drivers/net/phy/phy-c45.c | 180 ++++++++++++++++++++++++++
include/linux/phy.h | 6 +
7 files changed, 433 insertions(+)
create mode 100644 drivers/net/phy/mdio-open-alliance.h
create mode 100644 drivers/net/phy/ncn26000.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 7952243e4b43..09f0bfa3ae64 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15357,6 +15357,13 @@ L: linux-mips@vger.kernel.org
S: Maintained
F: arch/mips/boot/dts/ralink/omega2p.dts

+ONSEMI ETHERNET PHY DRIVERS
+M: Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
+L: netdev@vger.kernel.org
+S: Supported
+W: http://www.onsemi.com
+F: drivers/net/phy/ncn*
+
OP-TEE DRIVER
M: Jens Wiklander <jens.wiklander@linaro.org>
L: op-tee@lists.trustedfirmware.org
@@ -16400,6 +16407,7 @@ PLCA RECONCILIATION SUBLAYER (IEEE802.3 Clause 148)
M: Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
L: netdev@vger.kernel.org
S: Maintained
+F: drivers/net/phy/mdio-open-alliance.h
F: net/ethtool/plca.c

PLDMFW LIBRARY
diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index af00cf44cd97..7c466830c611 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -267,6 +267,13 @@ config NATIONAL_PHY
help
Currently supports the DP83865 PHY.

+config NCN26000_PHY
+ tristate "onsemi 10BASE-T1S Ethernet PHY"
+ help
+ Adds support for the onsemi 10BASE-T1S Ethernet PHY.
+ Currently supports the NCN26000 10BASE-T1S Industrial PHY
+ with MII interface.
+
config NXP_C45_TJA11XX_PHY
tristate "NXP C45 TJA11XX PHYs"
depends on PTP_1588_CLOCK_OPTIONAL
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index f7138d3c896b..b5138066ba04 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -77,6 +77,7 @@ obj-$(CONFIG_MICROCHIP_T1_PHY) += microchip_t1.o
obj-$(CONFIG_MICROSEMI_PHY) += mscc/
obj-$(CONFIG_MOTORCOMM_PHY) += motorcomm.o
obj-$(CONFIG_NATIONAL_PHY) += national.o
+obj-$(CONFIG_NCN26000_PHY) += ncn26000.o
obj-$(CONFIG_NXP_C45_TJA11XX_PHY) += nxp-c45-tja11xx.o
obj-$(CONFIG_NXP_TJA11XX_PHY) += nxp-tja11xx.o
obj-$(CONFIG_QSEMI_PHY) += qsemi.o
diff --git a/drivers/net/phy/mdio-open-alliance.h b/drivers/net/phy/mdio-open-alliance.h
new file mode 100644
index 000000000000..565f4162611d
--- /dev/null
+++ b/drivers/net/phy/mdio-open-alliance.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * mdio-open-alliance.h - definition of OPEN Alliance SIG standard registers
+ */
+
+#ifndef __MDIO_OPEN_ALLIANCE__
+#define __MDIO_OPEN_ALLIANCE__
+
+#include <linux/mdio.h>
+
+/* MDIO Manageable Devices (MMDs). */
+#define MDIO_MMD_OATC14 MDIO_MMD_VEND2
+
+/* Open Alliance TC14 (10BASE-T1S) registers */
+#define MDIO_OATC14_PLCA_IDVER 0xca00 /* PLCA ID and version */
+#define MDIO_OATC14_PLCA_CTRL0 0xca01 /* PLCA Control register 0 */
+#define MDIO_OATC14_PLCA_CTRL1 0xca02 /* PLCA Control register 1 */
+#define MDIO_OATC14_PLCA_STATUS 0xca03 /* PLCA Status register */
+#define MDIO_OATC14_PLCA_TOTMR 0xca04 /* PLCA TO Timer register */
+#define MDIO_OATC14_PLCA_BURST 0xca05 /* PLCA BURST mode register */
+
+/* Open Alliance TC14 PLCA IDVER register */
+#define MDIO_OATC14_PLCA_IDM 0xff00 /* PLCA MAP ID */
+#define MDIO_OATC14_PLCA_VER 0x00ff /* PLCA MAP version */
+
+/* Open Alliance TC14 PLCA CTRL0 register */
+#define MDIO_OATC14_PLCA_EN 0x8000 /* PLCA enable */
+#define MDIO_OATC14_PLCA_RST 0x4000 /* PLCA reset */
+
+/* Open Alliance TC14 PLCA CTRL1 register */
+#define MDIO_OATC14_PLCA_NCNT 0xff00 /* PLCA node count */
+#define MDIO_OATC14_PLCA_ID 0x00ff /* PLCA local node ID */
+
+/* Open Alliance TC14 PLCA STATUS register */
+#define MDIO_OATC14_PLCA_PST 0x8000 /* PLCA status indication */
+
+/* Open Alliance TC14 PLCA TOTMR register */
+#define MDIO_OATC14_PLCA_TOT 0x00ff
+
+/* Open Alliance TC14 PLCA BURST register */
+#define MDIO_OATC14_PLCA_MAXBC 0xff00
+#define MDIO_OATC14_PLCA_BTMR 0x00ff
+
+#endif /* __MDIO_OPEN_ALLIANCE__ */
diff --git a/drivers/net/phy/ncn26000.c b/drivers/net/phy/ncn26000.c
new file mode 100644
index 000000000000..49d4fee20cbc
--- /dev/null
+++ b/drivers/net/phy/ncn26000.c
@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+/*
+ * Driver for the onsemi 10BASE-T1S NCN26000 PHYs family.
+ *
+ * Copyright 2022 onsemi
+ */
+#include <linux/kernel.h>
+#include <linux/bitfield.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mii.h>
+#include <linux/phy.h>
+
+#include "mdio-open-alliance.h"
+
+#define PHY_ID_NCN26000 0x180FF5A1
+
+#define NCN26000_REG_IRQ_CTL 16
+#define NCN26000_REG_IRQ_STATUS 17
+
+// the NCN26000 maps link_ctrl to BMCR_ANENABLE
+#define NCN26000_BCMR_LINK_CTRL_BIT BMCR_ANENABLE
+
+// the NCN26000 maps link_status to BMSR_ANEGCOMPLETE
+#define NCN26000_BMSR_LINK_STATUS_BIT BMSR_ANEGCOMPLETE
+
+#define NCN26000_IRQ_LINKST_BIT BIT(0)
+#define NCN26000_IRQ_PLCAST_BIT BIT(1)
+#define NCN26000_IRQ_LJABBER_BIT BIT(2)
+#define NCN26000_IRQ_RJABBER_BIT BIT(3)
+#define NCN26000_IRQ_PLCAREC_BIT BIT(4)
+#define NCN26000_IRQ_PHYSCOL_BIT BIT(5)
+
+#define TO_TMR_DEFAULT 32
+
+struct ncn26000_priv {
+ u16 enabled_irqs;
+};
+
+// module parameter: if set, the link status is derived from the PLCA status
+// default: false
+static bool link_status_plca;
+module_param(link_status_plca, bool, 0644);
+
+// driver callbacks
+
+static int ncn26000_config_init(struct phy_device *phydev)
+{
+ /* HW bug workaround: the default value of the PLCA TO_TIMER should be
+ * 32, where the current version of NCN26000 reports 24. This will be
+ * fixed in future PHY versions. For the time being, we force the
+ * correct default here.
+ */
+ return phy_write_mmd(phydev, MDIO_MMD_OATC14, MDIO_OATC14_PLCA_TOTMR,
+ TO_TMR_DEFAULT);
+}
+
+static int ncn26000_config_aneg(struct phy_device *phydev)
+{
+ // Note: the NCN26000 supports only P2MP link mode. Therefore, AN is not
+ // supported. However, this function is invoked by phylib to enable the
+ // PHY, regardless of the AN support.
+ phydev->mdix_ctrl = ETH_TP_MDI_AUTO;
+ phydev->mdix = ETH_TP_MDI;
+
+ // bring up the link
+ return phy_write(phydev, MII_BMCR, NCN26000_BCMR_LINK_CTRL_BIT);
+}
+
+static int ncn26000_get_features(struct phy_device *phydev)
+{
+ linkmode_zero(phydev->supported);
+ linkmode_set_bit(ETHTOOL_LINK_MODE_MII_BIT, phydev->supported);
+
+ linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT1S_P2MP_Half_BIT,
+ phydev->supported);
+
+ linkmode_copy(phydev->advertising, phydev->supported);
+ return 0;
+}
+
+static int ncn26000_read_status(struct phy_device *phydev)
+{
+ // The NCN26000 reports NCN26000_LINK_STATUS_BIT if the link status of
+ // the PHY is up. It further reports the logical AND of the link status
+ // and the PLCA status in the BMSR_LSTATUS bit. Thus, report the link
+ // status by testing the appropriate BMSR bit according to the module's
+ // parameter configuration.
+ const int lstatus_flag = link_status_plca ?
+ BMSR_LSTATUS : NCN26000_BMSR_LINK_STATUS_BIT;
+
+ int ret;
+
+ ret = phy_read(phydev, MII_BMSR);
+ if (unlikely(ret < 0))
+ return ret;
+
+ // update link status
+ phydev->link = (ret & lstatus_flag) ? 1 : 0;
+
+ // handle more IRQs here
+
+ return 0;
+}
+
+static irqreturn_t ncn26000_handle_interrupt(struct phy_device *phydev)
+{
+ const struct ncn26000_priv *const priv = phydev->priv;
+ int ret;
+
+ // clear the latched bits in MII_BMSR
+ phy_read(phydev, MII_BMSR);
+
+ // read and aknowledge the IRQ status register
+ ret = phy_read(phydev, NCN26000_REG_IRQ_STATUS);
+
+ if (unlikely(ret < 0) || (ret & priv->enabled_irqs) == 0)
+ return IRQ_NONE;
+
+ phy_trigger_machine(phydev);
+ return IRQ_HANDLED;
+}
+
+static int ncn26000_config_intr(struct phy_device *phydev)
+{
+ int ret;
+ struct ncn26000_priv *priv = phydev->priv;
+
+ if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
+ // acknowledge IRQs
+ ret = phy_read(phydev, NCN26000_REG_IRQ_STATUS);
+ if (ret < 0)
+ return ret;
+
+ // get link status notifications
+ priv->enabled_irqs = NCN26000_IRQ_LINKST_BIT;
+ } else {
+ // disable all IRQs
+ priv->enabled_irqs = 0;
+ }
+
+ ret = phy_write(phydev, NCN26000_REG_IRQ_CTL, priv->enabled_irqs);
+ if (ret != 0)
+ return ret;
+
+ return 0;
+}
+
+static int ncn26000_probe(struct phy_device *phydev)
+{
+ struct device *dev = &phydev->mdio.dev;
+ struct ncn26000_priv *priv;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ phydev->priv = priv;
+
+ return 0;
+}
+
+static struct phy_driver ncn26000_driver[] = {
+ {
+ PHY_ID_MATCH_MODEL(PHY_ID_NCN26000),
+ .name = "NCN26000",
+ .probe = ncn26000_probe,
+ .get_features = ncn26000_get_features,
+ .config_init = ncn26000_config_init,
+ .config_intr = ncn26000_config_intr,
+ .config_aneg = ncn26000_config_aneg,
+ .read_status = ncn26000_read_status,
+ .handle_interrupt = ncn26000_handle_interrupt,
+ .get_plca_cfg = genphy_c45_plca_get_cfg,
+ .set_plca_cfg = genphy_c45_plca_set_cfg,
+ .get_plca_status = genphy_c45_plca_get_status,
+ .soft_reset = genphy_soft_reset,
+ },
+};
+
+module_phy_driver(ncn26000_driver);
+
+MODULE_DEVICE_TABLE(mdio, ncn26000_tbl);
+MODULE_AUTHOR("Piergiorgio Beruto");
+MODULE_DESCRIPTION("onsemi 10BASE-T1S PHY driver");
+MODULE_LICENSE("Dual BSD/GPL");
diff --git a/drivers/net/phy/phy-c45.c b/drivers/net/phy/phy-c45.c
index a87a4b3ffce4..dace5d3b29ad 100644
--- a/drivers/net/phy/phy-c45.c
+++ b/drivers/net/phy/phy-c45.c
@@ -8,6 +8,8 @@
#include <linux/mii.h>
#include <linux/phy.h>

+#include "mdio-open-alliance.h"
+
/**
* genphy_c45_baset1_able - checks if the PMA has BASE-T1 extended abilities
* @phydev: target phy_device struct
@@ -931,6 +933,184 @@ int genphy_c45_fast_retrain(struct phy_device *phydev, bool enable)
}
EXPORT_SYMBOL_GPL(genphy_c45_fast_retrain);

+/**
+ * genphy_c45_plca_get_cfg - get PLCA configuration from standard registers
+ * @phydev: target phy_device struct
+ * @plca_cfg: output structure to store the PLCA configuration
+ *
+ * Description: if the PHY complies to the Open Alliance TC14 10BASE-T1S PLCA
+ * Management Registers specifications, this function can be used to retrieve
+ * the current PLCA configuration from the standard registers in MMD 31.
+ */
+int genphy_c45_plca_get_cfg(struct phy_device *phydev,
+ struct phy_plca_cfg *plca_cfg)
+{
+ int ret;
+
+ ret = phy_read_mmd(phydev, MDIO_MMD_OATC14, MDIO_OATC14_PLCA_IDVER);
+ if (ret < 0)
+ return ret;
+
+ plca_cfg->version = ret;
+
+ ret = phy_read_mmd(phydev, MDIO_MMD_OATC14, MDIO_OATC14_PLCA_CTRL0);
+ if (ret < 0)
+ return ret;
+
+ plca_cfg->enabled = !!(ret & MDIO_OATC14_PLCA_EN);
+
+ ret = phy_read_mmd(phydev, MDIO_MMD_OATC14, MDIO_OATC14_PLCA_CTRL1);
+ if (ret < 0)
+ return ret;
+
+ plca_cfg->node_cnt = (ret & MDIO_OATC14_PLCA_NCNT) >> 8;
+ plca_cfg->node_id = (ret & MDIO_OATC14_PLCA_ID);
+
+ ret = phy_read_mmd(phydev, MDIO_MMD_OATC14, MDIO_OATC14_PLCA_TOTMR);
+ if (ret < 0)
+ return ret;
+
+ plca_cfg->to_tmr = ret & MDIO_OATC14_PLCA_TOT;
+
+ ret = phy_read_mmd(phydev, MDIO_MMD_OATC14, MDIO_OATC14_PLCA_BURST);
+ if (ret < 0)
+ return ret;
+
+ plca_cfg->burst_cnt = (ret & MDIO_OATC14_PLCA_MAXBC) >> 8;
+ plca_cfg->burst_tmr = (ret & MDIO_OATC14_PLCA_BTMR);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(genphy_c45_plca_get_cfg);
+
+/**
+ * genphy_c45_plca_set_cfg - set PLCA configuration using standard registers
+ * @phydev: target phy_device struct
+ * @plca_cfg: structure containing the PLCA configuration. Fields set to -1 are
+ * not to be changed.
+ *
+ * Description: if the PHY complies to the Open Alliance TC14 10BASE-T1S PLCA
+ * Management Registers specifications, this function can be used to modify
+ * the PLCA configuration using the standard registers in MMD 31.
+ */
+int genphy_c45_plca_set_cfg(struct phy_device *phydev,
+ const struct phy_plca_cfg *plca_cfg)
+{
+ int ret;
+ u16 val;
+
+ // PLCA IDVER is read-only
+ if (plca_cfg->version >= 0)
+ return -EINVAL;
+
+ // first of all, disable PLCA if required
+ if (plca_cfg->enabled == 0) {
+ ret = phy_clear_bits_mmd(phydev, MDIO_MMD_OATC14,
+ MDIO_OATC14_PLCA_CTRL0,
+ MDIO_OATC14_PLCA_EN);
+
+ if (ret < 0)
+ return ret;
+ }
+
+ if (plca_cfg->node_cnt >= 0 || plca_cfg->node_id >= 0) {
+ if (plca_cfg->node_cnt < 0 || plca_cfg->node_id < 0) {
+ ret = phy_read_mmd(phydev, MDIO_MMD_OATC14,
+ MDIO_OATC14_PLCA_CTRL1);
+
+ if (ret < 0)
+ return ret;
+
+ val = ret;
+ }
+
+ if (plca_cfg->node_cnt >= 0)
+ val = (val & ~MDIO_OATC14_PLCA_NCNT) |
+ (plca_cfg->node_cnt << 8);
+
+ if (plca_cfg->node_id >= 0)
+ val = (val & ~MDIO_OATC14_PLCA_ID) |
+ (plca_cfg->node_id);
+
+ ret = phy_write_mmd(phydev, MDIO_MMD_OATC14,
+ MDIO_OATC14_PLCA_CTRL1, val);
+
+ if (ret < 0)
+ return ret;
+ }
+
+ if (plca_cfg->to_tmr >= 0) {
+ ret = phy_write_mmd(phydev, MDIO_MMD_OATC14,
+ MDIO_OATC14_PLCA_TOTMR,
+ plca_cfg->to_tmr);
+
+ if (ret < 0)
+ return ret;
+ }
+
+ if (plca_cfg->burst_cnt >= 0 || plca_cfg->burst_tmr >= 0) {
+ if (plca_cfg->burst_cnt < 0 || plca_cfg->burst_tmr < 0) {
+ ret = phy_read_mmd(phydev, MDIO_MMD_OATC14,
+ MDIO_OATC14_PLCA_BURST);
+
+ if (ret < 0)
+ return ret;
+
+ val = ret;
+ }
+
+ if (plca_cfg->burst_cnt >= 0)
+ val = (val & ~MDIO_OATC14_PLCA_MAXBC) |
+ (plca_cfg->burst_cnt << 8);
+
+ if (plca_cfg->burst_tmr >= 0)
+ val = (val & ~MDIO_OATC14_PLCA_BTMR) |
+ (plca_cfg->burst_tmr);
+
+ ret = phy_write_mmd(phydev, MDIO_MMD_OATC14,
+ MDIO_OATC14_PLCA_BURST, val);
+
+ if (ret < 0)
+ return ret;
+ }
+
+ // if we need to enable PLCA, do it at the end
+ if (plca_cfg->enabled > 0) {
+ ret = phy_set_bits_mmd(phydev, MDIO_MMD_OATC14,
+ MDIO_OATC14_PLCA_CTRL0,
+ MDIO_OATC14_PLCA_EN);
+
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(genphy_c45_plca_set_cfg);
+
+/**
+ * genphy_c45_plca_get_status - get PLCA status from standard registers
+ * @phydev: target phy_device struct
+ * @plca_st: output structure to store the PLCA status
+ *
+ * Description: if the PHY complies to the Open Alliance TC14 10BASE-T1S PLCA
+ * Management Registers specifications, this function can be used to retrieve
+ * the current PLCA status information from the standard registers in MMD 31.
+ */
+int genphy_c45_plca_get_status(struct phy_device *phydev,
+ struct phy_plca_status *plca_st)
+{
+ int ret;
+
+ ret = phy_read_mmd(phydev, MDIO_MMD_OATC14, MDIO_OATC14_PLCA_STATUS);
+ if (ret < 0)
+ return ret;
+
+ plca_st->pst = !!(ret & MDIO_OATC14_PLCA_PST);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(genphy_c45_plca_get_status);
+
struct phy_driver genphy_c45_driver = {
.phy_id = 0xffffffff,
.phy_id_mask = 0xffffffff,
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 49d0488bf480..4548c8e8f6a9 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -1745,6 +1745,12 @@ int genphy_c45_loopback(struct phy_device *phydev, bool enable);
int genphy_c45_pma_resume(struct phy_device *phydev);
int genphy_c45_pma_suspend(struct phy_device *phydev);
int genphy_c45_fast_retrain(struct phy_device *phydev, bool enable);
+int genphy_c45_plca_get_cfg(struct phy_device *phydev,
+ struct phy_plca_cfg *plca_cfg);
+int genphy_c45_plca_set_cfg(struct phy_device *phydev,
+ const struct phy_plca_cfg *plca_cfg);
+int genphy_c45_plca_get_status(struct phy_device *phydev,
+ struct phy_plca_status *plca_st);

/* Generic C45 PHY driver */
extern struct phy_driver genphy_c45_driver;
--
2.35.1