net: phy: lxt: implement generic .handle_interrupt() callback

In an attempt to actually support shared IRQs in phylib, we now move the
responsibility of triggering the phylib state machine or just returning
IRQ_NONE, based on the IRQ status register, to the PHY driver. Having
3 different IRQ handling callbacks (.handle_interrupt(),
.did_interrupt() and .ack_interrupt() ) is confusing so let the PHY
driver implement directly an IRQ handler like any other device driver.
Make this driver follow the new convention.

Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/phy/lxt.c

@@ -37,6 +37,8 @@
 
 #define MII_LXT970_ISR       18  /* Interrupt Status Register */
 
+#define MII_LXT970_IRS_MINT  BIT(15)
+
 #define MII_LXT970_CONFIG    19  /* Configuration Register    */
 
 /* ------------------------------------------------------------------------- */
@@ -47,6 +49,7 @@
 #define MII_LXT971_IER_IEN	0x00f2
 
 #define MII_LXT971_ISR		19  /* Interrupt Status Register */
+#define MII_LXT971_ISR_MASK	0x00f0
 
 /* register definitions for the 973 */
 #define MII_LXT973_PCR 16 /* Port Configuration Register */
@@ -81,6 +84,33 @@ static int lxt970_config_intr(struct phy_device *phydev)
 		return phy_write(phydev, MII_LXT970_IER, 0);
 }
 
+static irqreturn_t lxt970_handle_interrupt(struct phy_device *phydev)
+{
+	int irq_status;
+
+	/* The interrupt status register is cleared by reading BMSR
+	 * followed by MII_LXT970_ISR
+	 */
+	irq_status = phy_read(phydev, MII_BMSR);
+	if (irq_status < 0) {
+		phy_error(phydev);
+		return IRQ_NONE;
+	}
+
+	irq_status = phy_read(phydev, MII_LXT970_ISR);
+	if (irq_status < 0) {
+		phy_error(phydev);
+		return IRQ_NONE;
+	}
+
+	if (!(irq_status & MII_LXT970_IRS_MINT))
+		return IRQ_NONE;
+
+	phy_trigger_machine(phydev);
+
+	return IRQ_HANDLED;
+}
+
 static int lxt970_config_init(struct phy_device *phydev)
 {
 	return phy_write(phydev, MII_LXT970_CONFIG, 0);
@@ -105,6 +135,24 @@ static int lxt971_config_intr(struct phy_device *phydev)
 		return phy_write(phydev, MII_LXT971_IER, 0);
 }
 
+static irqreturn_t lxt971_handle_interrupt(struct phy_device *phydev)
+{
+	int irq_status;
+
+	irq_status = phy_read(phydev, MII_LXT971_ISR);
+	if (irq_status < 0) {
+		phy_error(phydev);
+		return IRQ_NONE;
+	}
+
+	if (!(irq_status & MII_LXT971_ISR_MASK))
+		return IRQ_NONE;
+
+	phy_trigger_machine(phydev);
+
+	return IRQ_HANDLED;
+}
+
 /*
  * A2 version of LXT973 chip has an ERRATA: it randomly return the contents
  * of the previous even register when you read a odd register regularly
@@ -239,13 +287,15 @@ static struct phy_driver lxt97x_driver[] = {
 	.config_init	= lxt970_config_init,
 	.ack_interrupt	= lxt970_ack_interrupt,
 	.config_intr	= lxt970_config_intr,
+	.handle_interrupt = lxt970_handle_interrupt,
 }, {
 	.phy_id		= 0x001378e0,
 	.name		= "LXT971",
 	.phy_id_mask	= 0xfffffff0,
 	/* PHY_BASIC_FEATURES */
 	.ack_interrupt	= lxt971_ack_interrupt,
 	.config_intr	= lxt971_config_intr,
+	.handle_interrupt = lxt971_handle_interrupt,
 	.suspend	= genphy_suspend,
 	.resume		= genphy_resume,
 }, {