[PATCH net-next] net: phy: mchp: Add support for LAN8804 PHY

[Horatiu Vultur]

The LAN8804 PHY has same features as that of LAN8814 PHY except that it
doesn't support 1588, SyncE or Q-USGMII.

This PHY is found inside the LAN966X switches.

Signed-off-by: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>
---
 drivers/net/phy/micrel.c   | 74 ++++++++++++++++++++++++++++++++++++++
 include/linux/micrel_phy.h |  1 +
 2 files changed, 75 insertions(+)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 5c928f827173..c330a5a9f665 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -1537,6 +1537,65 @@ static int ksz886x_cable_test_get_status(struct phy_device *phydev,
 	return ret;
 }
 
+#define LAN_EXT_PAGE_ACCESS_CONTROL			0x16
+#define LAN_EXT_PAGE_ACCESS_ADDRESS_DATA		0x17
+#define LAN_EXT_PAGE_ACCESS_CTRL_EP_FUNC		0x4000
+
+#define LAN8804_ALIGN_SWAP				0x4a
+#define LAN8804_ALIGN_TX_A_B_SWAP			0x1
+#define LAN8804_ALIGN_TX_A_B_SWAP_MASK			GENMASK(2, 0)
+#define LAN8814_CLOCK_MANAGEMENT			0xd
+#define LAN8814_LINK_QUALITY				0x8e
+
+static int lanphy_read_page_reg(struct phy_device *phydev, int page, u32 addr)
+{
+	u32 data;
+
+	phy_write(phydev, LAN_EXT_PAGE_ACCESS_CONTROL, page);
+	phy_write(phydev, LAN_EXT_PAGE_ACCESS_ADDRESS_DATA, addr);
+	phy_write(phydev, LAN_EXT_PAGE_ACCESS_CONTROL,
+		  (page | LAN_EXT_PAGE_ACCESS_CTRL_EP_FUNC));
+	data = phy_read(phydev, LAN_EXT_PAGE_ACCESS_ADDRESS_DATA);
+
+	return data;
+}
+
+static int lanphy_write_page_reg(struct phy_device *phydev, int page, u16 addr,
+				 u16 val)
+{
+	phy_write(phydev, LAN_EXT_PAGE_ACCESS_CONTROL, page);
+	phy_write(phydev, LAN_EXT_PAGE_ACCESS_ADDRESS_DATA, addr);
+	phy_write(phydev, LAN_EXT_PAGE_ACCESS_CONTROL,
+		  (page | LAN_EXT_PAGE_ACCESS_CTRL_EP_FUNC));
+
+	val = phy_write(phydev, LAN_EXT_PAGE_ACCESS_ADDRESS_DATA, val);
+	if (val) {
+		phydev_err(phydev, "Error: phy_write has returned error %d\n",
+			   val);
+		return val;
+	}
+	return 0;
+}
+
+static int lan8804_config_init(struct phy_device *phydev)
+{
+	int val;
+
+	/* MDI-X setting for swap A,B transmit */
+	val = lanphy_read_page_reg(phydev, 2, LAN8804_ALIGN_SWAP);
+	val &= ~LAN8804_ALIGN_TX_A_B_SWAP_MASK;
+	val |= LAN8804_ALIGN_TX_A_B_SWAP;
+	lanphy_write_page_reg(phydev, 2, LAN8804_ALIGN_SWAP, val);
+
+	/* Make sure that the PHY will not stop generating the clock when the
+	 * link partner goes down
+	 */
+	lanphy_write_page_reg(phydev, 31, LAN8814_CLOCK_MANAGEMENT, 0x27e);
+	lanphy_read_page_reg(phydev, 1, LAN8814_LINK_QUALITY);
+
+	return 0;
+}
+
 static struct phy_driver ksphy_driver[] = {
 {
 	.phy_id		= PHY_ID_KS8737,
@@ -1718,6 +1777,20 @@ static struct phy_driver ksphy_driver[] = {
 	.get_stats	= kszphy_get_stats,
 	.suspend	= genphy_suspend,
 	.resume		= kszphy_resume,
+}, {
+	.phy_id		= PHY_ID_LAN8804,
+	.phy_id_mask	= MICREL_PHY_ID_MASK,
+	.name		= "Microchip LAN966X Gigabit PHY",
+	.config_init	= lan8804_config_init,
+	.driver_data	= &ksz9021_type,
+	.probe		= kszphy_probe,
+	.soft_reset	= genphy_soft_reset,
+	.read_status	= ksz9031_read_status,
+	.get_sset_count	= kszphy_get_sset_count,
+	.get_strings	= kszphy_get_strings,
+	.get_stats	= kszphy_get_stats,
+	.suspend	= genphy_suspend,
+	.resume		= kszphy_resume,
 }, {
 	.phy_id		= PHY_ID_KSZ9131,
 	.phy_id_mask	= MICREL_PHY_ID_MASK,
@@ -1794,6 +1867,7 @@ static struct mdio_device_id __maybe_unused micrel_tbl[] = {
 	{ PHY_ID_KSZ8873MLL, MICREL_PHY_ID_MASK },
 	{ PHY_ID_KSZ886X, MICREL_PHY_ID_MASK },
 	{ PHY_ID_LAN8814, MICREL_PHY_ID_MASK },
+	{ PHY_ID_LAN8804, MICREL_PHY_ID_MASK },
 	{ }
 };
 
diff --git a/include/linux/micrel_phy.h b/include/linux/micrel_phy.h
index 3d43c60b49fa..1f7c33b2f5a3 100644
--- a/include/linux/micrel_phy.h
+++ b/include/linux/micrel_phy.h
@@ -28,6 +28,7 @@
 #define PHY_ID_KSZ9031		0x00221620
 #define PHY_ID_KSZ9131		0x00221640
 #define PHY_ID_LAN8814		0x00221660
+#define PHY_ID_LAN8804		0x00221670
 
 #define PHY_ID_KSZ886X		0x00221430
 #define PHY_ID_KSZ8863		0x00221435
-- 
2.33.0