[PATCH v4 1/2] net: phy: Add Cortina CS4340 driver

From: Bogdan Purcareata
Date: Mon May 29 2017 - 05:11:46 EST


Add basic support for Cortina PHY drivers. Support only CS4340 for now.
The phys are not compatible with IEEE 802.3 clause 22/45 registers.

Implement proper read_status support. The generic 10G phy driver causes
bus register access errors.

The driver should be described using the "ethernet-phy-id" device tree
compatible.

Signed-off-by: Bogdan Purcareata <bogdan.purcareata@xxxxxxx>
---
v3 -> v4:
- Add CORTINA trademark info.
- Change id_lsb and id_msb from u32 to int to cover error checking.

v2 -> v3:
- Add probe function to check the device we're talking with is the same
as the one described in the device tree.
- Change the link status (GPIO interrupt status) register and validate
that the read is done from the right place (cable plug-in / plug-out).
- Some functions + Kconfig entry renaming.

v1 -> v2:
- Rename "mdio-cortina.c" to "cortina.c" since it's a phy driver.
- Test probing based on the "ethernet-phy-id" compatible. In the previous
version, getting the phy_id via get_phy_c45_ids() involved an additional
hack. Drop that approach and document probing in the commit message.

drivers/net/phy/Kconfig | 5 ++
drivers/net/phy/Makefile | 1 +
drivers/net/phy/cortina.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 124 insertions(+)
create mode 100644 drivers/net/phy/cortina.c

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 22dea7f..12c033c 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -240,6 +240,11 @@ config CICADA_PHY
---help---
Currently supports the cis8204

+config CORTINA_PHY
+ tristate "Cortina EDC CDR 10G Ethernet PHY"
+ ---help---
+ Currently supports the CS4340 phy.
+
config DAVICOM_PHY
tristate "Davicom PHYs"
---help---
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 79365be..0de3e20 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_BCM_CYGNUS_PHY) += bcm-cygnus.o
obj-$(CONFIG_BCM_NET_PHYLIB) += bcm-phy-lib.o
obj-$(CONFIG_BROADCOM_PHY) += broadcom.o
obj-$(CONFIG_CICADA_PHY) += cicada.o
+obj-$(CONFIG_CORTINA_PHY) += cortina.o
obj-$(CONFIG_DAVICOM_PHY) += davicom.o
obj-$(CONFIG_DP83640_PHY) += dp83640.o
obj-$(CONFIG_DP83848_PHY) += dp83848.o
diff --git a/drivers/net/phy/cortina.c b/drivers/net/phy/cortina.c
new file mode 100644
index 0000000..72f4228
--- /dev/null
+++ b/drivers/net/phy/cortina.c
@@ -0,0 +1,118 @@
+/*
+ * Copyright 2017 NXP
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * CORTINA is a registered trademark of Cortina Systems, Inc.
+ *
+ */
+#include <linux/module.h>
+#include <linux/phy.h>
+
+#define PHY_ID_CS4340 0x13e51002
+
+#define VILLA_GLOBAL_CHIP_ID_LSB 0x0
+#define VILLA_GLOBAL_CHIP_ID_MSB 0x1
+
+#define VILLA_GLOBAL_GPIO_1_INTS 0x017
+
+static int cortina_read_reg(struct phy_device *phydev, u16 regnum)
+{
+ return mdiobus_read(phydev->mdio.bus, phydev->mdio.addr,
+ MII_ADDR_C45 | regnum);
+}
+
+static int cortina_config_aneg(struct phy_device *phydev)
+{
+ phydev->supported = SUPPORTED_10000baseT_Full;
+ phydev->advertising = SUPPORTED_10000baseT_Full;
+
+ return 0;
+}
+
+static int cortina_read_status(struct phy_device *phydev)
+{
+ int gpio_int_status, ret = 0;
+
+ gpio_int_status = cortina_read_reg(phydev, VILLA_GLOBAL_GPIO_1_INTS);
+ if (gpio_int_status < 0) {
+ ret = gpio_int_status;
+ goto err;
+ }
+
+ if (gpio_int_status & 0x8) {
+ /* up when edc_convergedS set */
+ phydev->speed = SPEED_10000;
+ phydev->duplex = DUPLEX_FULL;
+ phydev->link = 1;
+ } else {
+ phydev->link = 0;
+ }
+
+err:
+ return ret;
+}
+
+static int cortina_soft_reset(struct phy_device *phydev)
+{
+ return 0;
+}
+
+static int cortina_probe(struct phy_device *phydev)
+{
+ u32 phy_id = 0;
+ int id_lsb = 0, id_msb = 0;
+
+ /* Read device id from phy registers. */
+ id_lsb = cortina_read_reg(phydev, VILLA_GLOBAL_CHIP_ID_LSB);
+ if (id_lsb < 0)
+ return -ENXIO;
+
+ phy_id = id_lsb << 16;
+
+ id_msb = cortina_read_reg(phydev, VILLA_GLOBAL_CHIP_ID_MSB);
+ if (id_msb < 0)
+ return -ENXIO;
+
+ phy_id |= id_msb;
+
+ /* Make sure the device tree binding matched the driver with the
+ * right device.
+ */
+ if (phy_id != phydev->drv->phy_id) {
+ phydev_err(phydev, "Error matching phy with %s driver\n",
+ phydev->drv->name);
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static struct phy_driver cortina_driver[] = {
+{
+ .phy_id = PHY_ID_CS4340,
+ .phy_id_mask = 0xffffffff,
+ .name = "Cortina CS4340",
+ .config_aneg = cortina_config_aneg,
+ .read_status = cortina_read_status,
+ .soft_reset = cortina_soft_reset,
+ .probe = cortina_probe,
+},
+};
+
+module_phy_driver(cortina_driver);
+
+static struct mdio_device_id __maybe_unused cortina_tbl[] = {
+ { PHY_ID_CS4340, 0xffffffff},
+ {},
+};
+
+MODULE_DEVICE_TABLE(mdio, cortina_tbl);
--
1.9.1