[PATCH RFC net-next+ 3/9] phy: qcom-sgmii-eth: add .set_mode() and .validate() methods

["Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>]

qcom-sgmii-eth is an Ethernet SerDes supporting only Ethernet mode
using SGMII, 1000BASE-X and 2500BASE-X.

Add an implementation of the .set_mode() method, which can be used
instead of or as well as the .set_speed() method. The Ethernet
interface modes mentioned above all have a fixed data rate, so
setting the mode is sufficient to fully specify the operating
parameters.

Add an implementation of the .validate() method, which will be
necessary to allow discovery of the SerDes capabilities for platform
independent SerDes support in the stmmac network driver.

Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/phy/qualcomm/phy-qcom-sgmii-eth.c | 43 +++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/drivers/phy/qualcomm/phy-qcom-sgmii-eth.c b/drivers/phy/qualcomm/phy-qcom-sgmii-eth.c
index 5b1c82459c12..4ea3dce7719f 100644
--- a/drivers/phy/qualcomm/phy-qcom-sgmii-eth.c
+++ b/drivers/phy/qualcomm/phy-qcom-sgmii-eth.c
@@ -7,6 +7,7 @@
 #include <linux/ethtool.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/phy.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
@@ -286,6 +287,37 @@ static int qcom_dwmac_sgmii_phy_power_off(struct phy *phy)
 	return 0;
 }
 
+static int qcom_dwmac_sgmii_phy_speed(enum phy_mode mode, int submode)
+{
+	if (mode != PHY_MODE_ETHERNET)
+		return -EINVAL;
+
+	if (submode == PHY_INTERFACE_MODE_SGMII ||
+	    submode == PHY_INTERFACE_MODE_1000BASEX)
+		return SPEED_1000;
+
+	if (submode == PHY_INTERFACE_MODE_2500BASEX)
+		return SPEED_2500;
+
+	return -EINVAL;
+}
+
+static int qcom_dwmac_sgmii_phy_set_mode(struct phy *phy, enum phy_mode mode,
+					 int submode)
+{
+	struct qcom_dwmac_sgmii_phy_data *data = phy_get_drvdata(phy);
+	int speed;
+
+	speed = qcom_dwmac_sgmii_phy_speed(mode, submode);
+	if (speed < 0)
+		return speed;
+
+	if (speed != data->speed)
+		data->speed = speed;
+
+	return qcom_dwmac_sgmii_phy_calibrate(phy);
+}
+
 static int qcom_dwmac_sgmii_phy_set_speed(struct phy *phy, int speed)
 {
 	struct qcom_dwmac_sgmii_phy_data *data = phy_get_drvdata(phy);
@@ -296,10 +328,21 @@ static int qcom_dwmac_sgmii_phy_set_speed(struct phy *phy, int speed)
 	return qcom_dwmac_sgmii_phy_calibrate(phy);
 }
 
+static int qcom_dwmac_sgmii_phy_validate(struct phy *phy, enum phy_mode mode,
+					 int submode,
+					 union phy_configure_opts *opts)
+{
+	int ret = qcom_dwmac_sgmii_phy_speed(mode, submode);
+
+	return ret < 0 ? ret : 0;
+}
+
 static const struct phy_ops qcom_dwmac_sgmii_phy_ops = {
 	.power_on	= qcom_dwmac_sgmii_phy_power_on,
 	.power_off	= qcom_dwmac_sgmii_phy_power_off,
+	.set_mode	= qcom_dwmac_sgmii_phy_set_mode,
 	.set_speed	= qcom_dwmac_sgmii_phy_set_speed,
+	.validate	= qcom_dwmac_sgmii_phy_validate,
 	.calibrate	= qcom_dwmac_sgmii_phy_calibrate,
 	.owner		= THIS_MODULE,
 };
-- 
2.47.3