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From:   Christian Eggers <ceggers@arri.de>
To:     Vladimir Oltean <olteanv@gmail.com>,
        Jakub Kicinski <kuba@kernel.org>, Andrew Lunn <andrew@lunn.ch>,
        Richard Cochran <richardcochran@gmail.com>,
        "Rob Herring" <robh+dt@kernel.org>
CC:     Vivien Didelot <vivien.didelot@gmail.com>,
        "David S . Miller" <davem@davemloft.net>,
        Kurt Kanzenbach <kurt.kanzenbach@linutronix.de>,
        George McCollister <george.mccollister@gmail.com>,
        Marek Vasut <marex@denx.de>,
        Helmut Grohne <helmut.grohne@intenta.de>,
        Paul Barker <pbarker@konsulko.com>,
        Codrin Ciubotariu <codrin.ciubotariu@microchip.com>,
        Tristram Ha <Tristram.Ha@microchip.com>,
        Woojung Huh <woojung.huh@microchip.com>,
        Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>,
        Christian Eggers <ceggers@arri.de>, <netdev@vger.kernel.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH net-next v5 4/9] net: dsa: microchip: ksz9477: basic interrupt support
Date:   Thu, 3 Dec 2020 11:21:12 +0100
Message-ID: <20201203102117.8995-5-ceggers@arri.de>
In-Reply-To: <20201203102117.8995-1-ceggers@arri.de>
References: <20201203102117.8995-1-ceggers@arri.de>
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Precedence: bulk

Interrupts are required for TX time stamping. Probably they could also
be used for PHY connection status.

This patch only adds the basic infrastructure for interrupts, no
interrupts are finally enabled nor handled.

Signed-off-by: Christian Eggers <ceggers@arri.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
---
Changes in v4:
--------------
- s/low active/active low/
- Reviewed-by: Vladimir Oltean <olteanv@gmail.com>

 drivers/net/dsa/microchip/ksz9477_i2c.c  |  2 +
 drivers/net/dsa/microchip/ksz9477_main.c | 68 ++++++++++++++++++++++++
 drivers/net/dsa/microchip/ksz9477_spi.c  |  2 +
 drivers/net/dsa/microchip/ksz_common.h   |  1 +
 4 files changed, 73 insertions(+)

diff --git a/drivers/net/dsa/microchip/ksz9477_i2c.c b/drivers/net/dsa/microchip/ksz9477_i2c.c
index 4e053a25d077..4ed1f503044a 100644
--- a/drivers/net/dsa/microchip/ksz9477_i2c.c
+++ b/drivers/net/dsa/microchip/ksz9477_i2c.c
@@ -41,6 +41,8 @@ static int ksz9477_i2c_probe(struct i2c_client *i2c,
 	if (i2c->dev.platform_data)
 		dev->pdata = i2c->dev.platform_data;
 
+	dev->irq = i2c->irq;
+
 	ret = ksz9477_switch_register(dev);
 
 	/* Main DSA driver may not be started yet. */
diff --git a/drivers/net/dsa/microchip/ksz9477_main.c b/drivers/net/dsa/microchip/ksz9477_main.c
index 681e752919ac..f869041e3be0 100644
--- a/drivers/net/dsa/microchip/ksz9477_main.c
+++ b/drivers/net/dsa/microchip/ksz9477_main.c
@@ -5,9 +5,12 @@
  * Copyright (C) 2017-2019 Microchip Technology Inc.
  */
 
+#include <linux/bits.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/interrupt.h>
 #include <linux/iopoll.h>
+#include <linux/irq.h>
 #include <linux/platform_data/microchip-ksz.h>
 #include <linux/phy.h>
 #include <linux/if_bridge.h>
@@ -1524,6 +1527,54 @@ static const struct ksz_chip_data ksz9477_switch_chips[] = {
 	},
 };
 
+static irqreturn_t ksz9477_switch_irq_thread(int irq, void *dev_id)
+{
+	struct ksz_device *dev = dev_id;
+	u32 data;
+	int port;
+	int ret;
+
+	/* Read global port interrupt status register */
+	ret = ksz_read32(dev, REG_SW_PORT_INT_STATUS__4, &data);
+	if (ret)
+		return IRQ_NONE;
+
+	for (port = 0; port < dev->port_cnt; port++) {
+		u8 data8;
+
+		if (!(data & BIT(port)))
+			continue;
+
+		/* Read port interrupt status register */
+		ret = ksz_read8(dev, PORT_CTRL_ADDR(port, REG_PORT_INT_STATUS),
+				&data8);
+		if (ret)
+			return IRQ_NONE;
+
+		/* ToDo: Add specific handling of port interrupts */
+	}
+
+	return IRQ_NONE;
+}
+
+static int ksz9477_enable_port_interrupts(struct ksz_device *dev, bool enable)
+{
+	u32 data, mask = GENMASK(dev->port_cnt - 1, 0);
+	int ret;
+
+	ret = ksz_read32(dev, REG_SW_PORT_INT_MASK__4, &data);
+	if (ret)
+		return ret;
+
+	/* bits in REG_SW_PORT_INT_MASK__4 are active low */
+	if (enable)
+		data &= ~mask;
+	else
+		data |= mask;
+
+	return ksz_write32(dev, REG_SW_PORT_INT_MASK__4, data);
+}
+
 static int ksz9477_switch_init(struct ksz_device *dev)
 {
 	int i, ret;
@@ -1579,12 +1630,29 @@ static int ksz9477_switch_init(struct ksz_device *dev)
 
 	/* set the real number of ports */
 	dev->ds->num_ports = dev->port_cnt;
+	if (dev->irq > 0) {
+		ret = devm_request_threaded_irq(dev->dev, dev->irq, NULL,
+						ksz9477_switch_irq_thread,
+						IRQF_ONESHOT | IRQF_SHARED,
+						dev_name(dev->dev),
+						dev);
+		if (ret) {
+			dev_err(dev->dev, "failed to request IRQ.\n");
+			return ret;
+		}
+
+		ret = ksz9477_enable_port_interrupts(dev, true);
+		if (ret)
+			return ret;
+	}
 
 	return 0;
 }
 
 static void ksz9477_switch_exit(struct ksz_device *dev)
 {
+	if (dev->irq > 0)
+		ksz9477_enable_port_interrupts(dev, false);
 	ksz9477_reset_switch(dev);
 }
 
diff --git a/drivers/net/dsa/microchip/ksz9477_spi.c b/drivers/net/dsa/microchip/ksz9477_spi.c
index 15bc11b3cda4..fc0ac9e2c56d 100644
--- a/drivers/net/dsa/microchip/ksz9477_spi.c
+++ b/drivers/net/dsa/microchip/ksz9477_spi.c
@@ -48,6 +48,8 @@ static int ksz9477_spi_probe(struct spi_device *spi)
 	if (spi->dev.platform_data)
 		dev->pdata = spi->dev.platform_data;
 
+	dev->irq = spi->irq;
+
 	/* setup spi */
 	spi->mode = SPI_MODE_3;
 	ret = spi_setup(spi);
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index 720f22275c84..ac6914d361c8 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -55,6 +55,7 @@ struct ksz_device {
 
 	struct device *dev;
 	struct regmap *regmap[3];
+	int irq;
 
 	void *priv;
 
-- 
Christian Eggers
Embedded software developer

Arnold & Richter Cine Technik GmbH & Co. Betriebs KG
Sitz: Muenchen - Registergericht: Amtsgericht Muenchen - Handelsregisternummer: HRA 57918
Persoenlich haftender Gesellschafter: Arnold & Richter Cine Technik GmbH
Sitz: Muenchen - Registergericht: Amtsgericht Muenchen - Handelsregisternummer: HRB 54477
Geschaeftsfuehrer: Dr. Michael Neuhaeuser; Stephan Schenk; Walter Trauninger; Markus Zeiler