[PATCH net-next 2/3] net: dsa: mv88e6xxx: Add minimal platform_data support

[Andrew Lunn <andrew@lunn.ch>]

Not all the world uses device tree. Some parts of the world still use
platform devices and platform data. Add basic support for probing a
Marvell switch via platform data.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
 MAINTAINERS                             |  1 +
 drivers/net/dsa/mv88e6xxx/chip.c        | 56 +++++++++++++++++++++----
 include/linux/platform_data/mv88e6xxx.h | 17 ++++++++
 3 files changed, 67 insertions(+), 7 deletions(-)
 create mode 100644 include/linux/platform_data/mv88e6xxx.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 658880464b9d..9f2045a5adac 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8466,6 +8466,7 @@ M:	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
 L:	netdev@vger.kernel.org
 S:	Maintained
 F:	drivers/net/dsa/mv88e6xxx/
+F:	linux/platform_data/mv88e6xxx.h
 F:	Documentation/devicetree/bindings/net/dsa/marvell.txt
 
 MARVELL ARMADA DRM SUPPORT
diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 2bb3f03ee1cb..5b40382036ea 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -28,6 +28,7 @@
 #include <linux/of_device.h>
 #include <linux/of_irq.h>
 #include <linux/of_mdio.h>
+#include <linux/platform_data/mv88e6xxx.h>
 #include <linux/netdevice.h>
 #include <linux/gpio/consumer.h>
 #include <linux/phy.h>
@@ -4350,6 +4351,7 @@ static int mv88e6xxx_register_switch(struct mv88e6xxx_chip *chip)
 		return -ENOMEM;
 
 	ds->priv = chip;
+	ds->dev = dev;
 	ds->ops = &mv88e6xxx_switch_ops;
 	ds->ageing_time_min = chip->info->age_time_coeff;
 	ds->ageing_time_max = chip->info->age_time_coeff * U8_MAX;
@@ -4364,36 +4366,73 @@ static void mv88e6xxx_unregister_switch(struct mv88e6xxx_chip *chip)
 	dsa_unregister_switch(chip->ds);
 }
 
+static const void *pdata_device_get_match_data(struct device *dev)
+{
+	const struct of_device_id *matches = dev->driver->of_match_table;
+	const struct dsa_mv88e6xxx_pdata *pdata = dev->platform_data;
+
+	for (; matches->name[0] || matches->type[0] || matches->compatible[0];
+	     matches++) {
+		if (!strcmp(pdata->compatible, matches->compatible))
+			return matches->data;
+	}
+	return NULL;
+}
+
 static int mv88e6xxx_probe(struct mdio_device *mdiodev)
 {
+	struct dsa_mv88e6xxx_pdata *pdata = mdiodev->dev.platform_data;
 	struct device *dev = &mdiodev->dev;
 	struct device_node *np = dev->of_node;
 	const struct mv88e6xxx_info *compat_info;
 	struct mv88e6xxx_chip *chip;
 	u32 eeprom_len;
+	int port;
 	int err;
 
-	compat_info = of_device_get_match_data(dev);
+	if (np)
+		compat_info = of_device_get_match_data(dev);
+
+	if (pdata) {
+		compat_info = pdata_device_get_match_data(dev);
+
+		if (!pdata->netdev)
+			return -EINVAL;
+
+		for (port = 0; port < DSA_MAX_PORTS; port++) {
+			if (!(pdata->enabled_ports & (1 << port)))
+				continue;
+			if (strcmp(pdata->cd.port_names[port], "cpu"))
+				continue;
+			pdata->cd.netdev[port] = &pdata->netdev->dev;
+			break;
+		}
+	}
+
 	if (!compat_info)
 		return -EINVAL;
 
 	chip = mv88e6xxx_alloc_chip(dev);
-	if (!chip)
-		return -ENOMEM;
+	if (!chip) {
+		err = -ENOMEM;
+		goto out;
+	}
 
 	chip->info = compat_info;
 
 	err = mv88e6xxx_smi_init(chip, mdiodev->bus, mdiodev->addr);
 	if (err)
-		return err;
+		goto out;
 
 	chip->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
-	if (IS_ERR(chip->reset))
-		return PTR_ERR(chip->reset);
+	if (IS_ERR(chip->reset)) {
+		err = PTR_ERR(chip->reset);
+		goto out;
+	}
 
 	err = mv88e6xxx_detect(chip);
 	if (err)
-		return err;
+		goto out;
 
 	mv88e6xxx_phy_init(chip);
 
@@ -4468,6 +4507,9 @@ static int mv88e6xxx_probe(struct mdio_device *mdiodev)
 		mv88e6xxx_irq_poll_free(chip);
 	mutex_unlock(&chip->reg_lock);
 out:
+	if (pdata)
+		dev_put(pdata->netdev);
+
 	return err;
 }
 
diff --git a/include/linux/platform_data/mv88e6xxx.h b/include/linux/platform_data/mv88e6xxx.h
new file mode 100644
index 000000000000..88e91e05f48f
--- /dev/null
+++ b/include/linux/platform_data/mv88e6xxx.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __DSA_MV88E6XXX_H
+#define __DSA_MV88E6XXX_H
+
+#include <net/dsa.h>
+
+struct dsa_mv88e6xxx_pdata {
+	/* Must be first, such that dsa_register_switch() can access this
+	 * without gory pointer manipulations
+	 */
+	struct dsa_chip_data cd;
+	const char *compatible;
+	unsigned int enabled_ports;
+	struct net_device *netdev;
+};
+
+#endif
-- 
2.17.0