[PATCH v4 net-next 4/5] drivers/net/phy: add helpers to get/set PLCA configuration

Piergiorgio Beruto
2022-12-06T12:53:53Z

This patch adds support in phylib to read/write PLCA configuration for
Ethernet PHYs that support the OPEN Alliance "10BASE-T1S PLCA
Management Registers" specifications. These can be found at
https://www.opensig.org/about/specifications/

Signed-off-by: Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
---
MAINTAINERS | 1 +
drivers/net/phy/mdio-open-alliance.h | 44 +++++++
drivers/net/phy/phy-c45.c | 180 +++++++++++++++++++++++++++
include/linux/phy.h | 6 +
4 files changed, 231 insertions(+)
create mode 100644 drivers/net/phy/mdio-open-alliance.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 7952243e4b43..ed626cbdf5af 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16400,6 +16400,7 @@ 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/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/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