[net-next,PATCH v2 2/5] net: ethernet: stmmac: stm32: support the phy-supply regulator binding

[Christophe Roullier <christophe.roullier@foss.st.com>]

Configure the phy regulator if defined by the "phy-supply" DT phandle.

Signed-off-by: Christophe Roullier <christophe.roullier@foss.st.com>
---
 .../net/ethernet/stmicro/stmmac/dwmac-stm32.c | 51 ++++++++++++++++++-
 1 file changed, 50 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
index e1b260ed4790b..4597f605ec1bb 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
@@ -14,6 +14,7 @@
 #include <linux/of_net.h>
 #include <linux/phy.h>
 #include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
 #include <linux/pm_wakeirq.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
@@ -98,6 +99,7 @@ struct stm32_dwmac {
 	u32 mode_reg;		 /* MAC glue-logic mode register */
 	u32 mode_mask;
 	struct regmap *regmap;
+	struct regulator *regulator;
 	u32 speed;
 	const struct stm32_ops *ops;
 	struct device *dev;
@@ -423,6 +425,16 @@ static int stm32_dwmac_parse_data(struct stm32_dwmac *dwmac,
 	if (IS_ERR(dwmac->regmap))
 		return PTR_ERR(dwmac->regmap);
 
+	dwmac->regulator = devm_regulator_get_optional(dev, "phy");
+	if (IS_ERR(dwmac->regulator)) {
+		if (PTR_ERR(dwmac->regulator) == -EPROBE_DEFER) {
+			dev_dbg(dev, "phy regulator is not available yet, deferred probing\n");
+			return -EPROBE_DEFER;
+		}
+		dev_dbg(dev, "no regulator found\n");
+		dwmac->regulator = NULL;
+	}
+
 	if (dwmac->ops->is_mp2)
 		return 0;
 
@@ -522,6 +534,27 @@ static int stm32_dwmac_resume(struct device *dev, void *bsp_priv)
 	return stm32_dwmac_init(priv->plat);
 }
 
+static int phy_power_on(struct stm32_dwmac *bsp_priv, bool enable)
+{
+	int ret;
+	struct device *dev = bsp_priv->dev;
+
+	if (!bsp_priv->regulator)
+		return 0;
+
+	if (enable) {
+		ret = regulator_enable(bsp_priv->regulator);
+		if (ret)
+			dev_err(dev, "fail to enable phy-supply\n");
+	} else {
+		ret = regulator_disable(bsp_priv->regulator);
+		if (ret)
+			dev_err(dev, "fail to disable phy-supply\n");
+	}
+
+	return 0;
+}
+
 static int stm32_dwmac_probe(struct platform_device *pdev)
 {
 	struct plat_stmmacenet_data *plat_dat;
@@ -576,12 +609,18 @@ static int stm32_dwmac_probe(struct platform_device *pdev)
 			goto err_clk_disable;
 	}
 
-	ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
+	ret = phy_power_on(plat_dat->bsp_priv, true);
 	if (ret)
 		goto err_clk_disable_suspend;
 
+	ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
+	if (ret)
+		goto err_gmac_powerdown;
+
 	return 0;
 
+err_gmac_powerdown:
+	phy_power_on(plat_dat->bsp_priv, false);
 err_clk_disable_suspend:
 	if (dwmac->ops->clk_rx_enable_in_suspend)
 		clk_disable_unprepare(dwmac->clk_rx);
@@ -614,16 +653,26 @@ static void stm32_dwmac_remove(struct platform_device *pdev)
 		dev_pm_clear_wake_irq(&pdev->dev);
 		device_init_wakeup(&pdev->dev, false);
 	}
+
+	phy_power_on(priv->plat->bsp_priv, false);
 }
 
 static int stm32mp1_suspend(struct stm32_dwmac *dwmac)
 {
+	/* Keep the PHY up if we use Wake-on-Lan. */
+	if (!device_may_wakeup(dwmac->dev))
+		phy_power_on(dwmac, false);
+
 	return clk_prepare_enable(dwmac->clk_ethstp);
 }
 
 static void stm32mp1_resume(struct stm32_dwmac *dwmac)
 {
 	clk_disable_unprepare(dwmac->clk_ethstp);
+
+	/* The PHY was up for Wake-on-Lan. */
+	if (!device_may_wakeup(dwmac->dev))
+		phy_power_on(dwmac, true);
 }
 
 static struct stm32_ops stm32mcu_dwmac_data = {
-- 
2.43.0