[PATCH v2] net: phy: add driver for MotorComm PHY

[yegorslists@googlemail.com]

From: Yegor Yefremov <yegorslists@googlemail.com>

The driver corresponds to the kernel 6.1.27.

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
---
Changes:
	v1 -> v2: add the related kernel version

 drivers/net/phy/Kconfig     |   5 ++
 drivers/net/phy/Makefile    |   1 +
 drivers/net/phy/motorcomm.c | 128 ++++++++++++++++++++++++++++++++++++
 3 files changed, 134 insertions(+)
 create mode 100644 drivers/net/phy/motorcomm.c

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index cd20e1de27..e95e2a3228 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -50,6 +50,11 @@ config MICREL_PHY
 	help
 	  Supports the KSZ9021, VSC8201, KS8001 PHYs.
 
+config MOTORCOMM_PHY
+	bool "Driver for Motorcomm PHYs"
+	help
+	  Currently supports the YT8511 PHY.
+
 config NATIONAL_PHY
 	bool "Driver for National Semiconductor PHYs"
 	help
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 83f46f11d3..26e4ad884d 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_DAVICOM_PHY)	+= davicom.o
 obj-$(CONFIG_LXT_PHY)		+= lxt.o
 obj-$(CONFIG_MARVELL_PHY)	+= marvell.o
 obj-$(CONFIG_MICREL_PHY)	+= micrel.o
+obj-$(CONFIG_MOTORCOMM_PHY)	+= motorcomm.o
 obj-$(CONFIG_NATIONAL_PHY)	+= national.o
 obj-$(CONFIG_REALTEK_PHY)	+= realtek.o
 obj-$(CONFIG_SMSC_PHY)		+= smsc.o
diff --git a/drivers/net/phy/motorcomm.c b/drivers/net/phy/motorcomm.c
new file mode 100644
index 0000000000..4bcd84342c
--- /dev/null
+++ b/drivers/net/phy/motorcomm.c
@@ -0,0 +1,128 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * drivers/net/phy/motorcomm.c
+ *
+ * Driver for Motorcomm PHYs
+ *
+ * Author: Peter Geis <pgwipeout@gmail.com>
+ */
+
+#include <common.h>
+#include <init.h>
+#include <linux/phy.h>
+#include <linux/mdio.h>
+
+#define PHY_ID_YT8511		0x0000010a
+
+#define YT8511_PAGE_SELECT	0x1e
+#define YT8511_PAGE		0x1f
+#define YT8511_EXT_CLK_GATE	0x0c
+#define YT8511_EXT_DELAY_DRIVE	0x0d
+#define YT8511_EXT_SLEEP_CTRL	0x27
+
+/* 2b00 25m from pll
+ * 2b01 25m from xtl *default*
+ * 2b10 62.m from pll
+ * 2b11 125m from pll
+ */
+#define YT8511_CLK_125M		(BIT(2) | BIT(1))
+#define YT8511_PLLON_SLP	BIT(14)
+
+/* RX Delay enabled = 1.8ns 1000T, 8ns 10/100T */
+#define YT8511_DELAY_RX		BIT(0)
+
+/* TX Gig-E Delay is bits 7:4, default 0x5
+ * TX Fast-E Delay is bits 15:12, default 0xf
+ * Delay = 150ps * N - 250ps
+ * On = 2000ps, off = 50ps
+ */
+#define YT8511_DELAY_GE_TX_EN	(0xf << 4)
+#define YT8511_DELAY_GE_TX_DIS	(0x2 << 4)
+#define YT8511_DELAY_FE_TX_EN	(0xf << 12)
+#define YT8511_DELAY_FE_TX_DIS	(0x2 << 12)
+
+static int yt8511_read_page(struct phy_device *phydev)
+{
+	return phy_read(phydev, YT8511_PAGE_SELECT);
+};
+
+static int yt8511_write_page(struct phy_device *phydev, int page)
+{
+	return phy_write(phydev, YT8511_PAGE_SELECT, page);
+};
+
+static int yt8511_config_init(struct phy_device *phydev)
+{
+	int oldpage, ret = 0;
+	unsigned int ge, fe;
+
+	oldpage = phy_select_page(phydev, YT8511_EXT_CLK_GATE);
+	if (oldpage < 0)
+		goto err_restore_page;
+
+	/* set rgmii delay mode */
+	switch (phydev->interface) {
+	case PHY_INTERFACE_MODE_RGMII:
+		ge = YT8511_DELAY_GE_TX_DIS;
+		fe = YT8511_DELAY_FE_TX_DIS;
+		break;
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+		ge = YT8511_DELAY_RX | YT8511_DELAY_GE_TX_DIS;
+		fe = YT8511_DELAY_FE_TX_DIS;
+		break;
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+		ge = YT8511_DELAY_GE_TX_EN;
+		fe = YT8511_DELAY_FE_TX_EN;
+		break;
+	case PHY_INTERFACE_MODE_RGMII_ID:
+		ge = YT8511_DELAY_RX | YT8511_DELAY_GE_TX_EN;
+		fe = YT8511_DELAY_FE_TX_EN;
+		break;
+	default: /* do not support other modes */
+		ret = -EOPNOTSUPP;
+		goto err_restore_page;
+	}
+
+	ret = phy_modify(phydev, YT8511_PAGE, (YT8511_DELAY_RX | YT8511_DELAY_GE_TX_EN), ge);
+	if (ret < 0)
+		goto err_restore_page;
+
+	/* set clock mode to 125mhz */
+	ret = phy_modify(phydev, YT8511_PAGE, 0, YT8511_CLK_125M);
+	if (ret < 0)
+		goto err_restore_page;
+
+	/* fast ethernet delay is in a separate page */
+	ret = phy_write(phydev, YT8511_PAGE_SELECT, YT8511_EXT_DELAY_DRIVE);
+	if (ret < 0)
+		goto err_restore_page;
+
+	ret = phy_modify(phydev, YT8511_PAGE, YT8511_DELAY_FE_TX_EN, fe);
+	if (ret < 0)
+		goto err_restore_page;
+
+	/* leave pll enabled in sleep */
+	ret = phy_write(phydev, YT8511_PAGE_SELECT, YT8511_EXT_SLEEP_CTRL);
+	if (ret < 0)
+		goto err_restore_page;
+
+	ret = phy_modify(phydev, YT8511_PAGE, 0, YT8511_PLLON_SLP);
+	if (ret < 0)
+		goto err_restore_page;
+
+err_restore_page:
+	return phy_restore_page(phydev, oldpage, ret);
+}
+
+static struct phy_driver motorcomm_phy_drvs[] = {
+	{
+		.phy_id		= PHY_ID_YT8511,
+		.drv.name	= "YT8511 Gigabit Ethernet",
+		.config_init	= yt8511_config_init,
+		.features	= PHY_GBIT_FEATURES,
+		.read_page	= yt8511_read_page,
+		.write_page	= yt8511_write_page,
+	},
+};
+
+device_phy_drivers(motorcomm_phy_drvs);
-- 
2.34.1