Merge branch 'enc28j60-small-improvements'

Michael Heimpold says:

====================
net: ethernet: enc28j60: small improvements

This series of two patches adds the following improvements to the driver:

1) Rework the central SPI read function so that it is compatible with
   SPI masters which only support half duplex transfers.

2) Add a device tree binding for the driver.

Changelog:

v3: * renamed and improved binding documentation as
      suggested by Rob Herring

v2: * took care of Arnd Bergmann's review comments
      - allow to specify MAC address via DT
      - unconditionally define DT id table
    * increased the driver version minor number
    * driver author's email address bounces, removed from address list

v1: * Initial submission
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/microchip,enc28j60.txt

@@ -0,0 +1,59 @@
+* Microchip ENC28J60
+
+This is a standalone 10 MBit ethernet controller with SPI interface.
+
+For each device connected to a SPI bus, define a child node within
+the SPI master node.
+
+Required properties:
+- compatible: Should be "microchip,enc28j60"
+- reg: Specify the SPI chip select the ENC28J60 is wired to
+- interrupt-parent: Specify the phandle of the source interrupt, see interrupt
+                    binding documentation for details. Usually this is the GPIO bank
+                    the interrupt line is wired to.
+- interrupts: Specify the interrupt index within the interrupt controller (referred
+              to above in interrupt-parent) and interrupt type. The ENC28J60 natively
+              generates falling edge interrupts, however, additional board logic
+              might invert the signal.
+- pinctrl-names: List of assigned state names, see pinctrl binding documentation.
+- pinctrl-0: List of phandles to configure the GPIO pin used as interrupt line,
+             see also generic and your platform specific pinctrl binding
+             documentation.
+
+Optional properties:
+- spi-max-frequency: Maximum frequency of the SPI bus when accessing the ENC28J60.
+  According to the ENC28J80 datasheet, the chip allows a maximum of 20 MHz, however,
+  board designs may need to limit this value.
+- local-mac-address: See ethernet.txt in the same directory.
+
+
+Example (for NXP i.MX28 with pin control stuff for GPIO irq):
+
+        ssp2: ssp@80014000 {
+                compatible = "fsl,imx28-spi";
+                pinctrl-names = "default";
+                pinctrl-0 = <&spi2_pins_b &spi2_sck_cfg>;
+                status = "okay";
+
+                enc28j60: ethernet@0 {
+                        compatible = "microchip,enc28j60";
+                        pinctrl-names = "default";
+                        pinctrl-0 = <&enc28j60_pins>;
+                        reg = <0>;
+                        interrupt-parent = <&gpio3>;
+                        interrupts = <3 IRQ_TYPE_EDGE_FALLING>;
+                        spi-max-frequency = <12000000>;
+                };
+        };
+
+        pinctrl@80018000 {
+                enc28j60_pins: enc28j60_pins@0 {
+                        reg = <0>;
+                        fsl,pinmux-ids = <
+                                MX28_PAD_AUART0_RTS__GPIO_3_3    /* Interrupt */
+                        >;
+                        fsl,drive-strength = <MXS_DRIVE_4mA>;
+                        fsl,voltage = <MXS_VOLTAGE_HIGH>;
+                        fsl,pull-up = <MXS_PULL_DISABLE>;
+                };
+        };

drivers/net/ethernet/microchip/enc28j60.c

@@ -28,11 +28,12 @@
 #include <linux/skbuff.h>
 #include <linux/delay.h>
 #include <linux/spi/spi.h>
+#include <linux/of_net.h>
 
 #include "enc28j60_hw.h"
 
 #define DRV_NAME	"enc28j60"
-#define DRV_VERSION	"1.01"
+#define DRV_VERSION	"1.02"
 
 #define SPI_OPLEN	1
 
@@ -89,22 +90,26 @@ spi_read_buf(struct enc28j60_net *priv, int len, u8 *data)
 {
 	u8 *rx_buf = priv->spi_transfer_buf + 4;
 	u8 *tx_buf = priv->spi_transfer_buf;
-	struct spi_transfer t = {
+	struct spi_transfer tx = {
 		.tx_buf = tx_buf,
+		.len = SPI_OPLEN,
+	};
+	struct spi_transfer rx = {
 		.rx_buf = rx_buf,
-		.len = SPI_OPLEN + len,
+		.len = len,
 	};
 	struct spi_message msg;
 	int ret;
 
 	tx_buf[0] = ENC28J60_READ_BUF_MEM;
-	tx_buf[1] = tx_buf[2] = tx_buf[3] = 0;	/* don't care */
 
 	spi_message_init(&msg);
-	spi_message_add_tail(&t, &msg);
+	spi_message_add_tail(&tx, &msg);
+	spi_message_add_tail(&rx, &msg);
+
 	ret = spi_sync(priv->spi, &msg);
 	if (ret == 0) {
-		memcpy(data, &rx_buf[SPI_OPLEN], len);
+		memcpy(data, rx_buf, len);
 		ret = msg.status;
 	}
 	if (ret && netif_msg_drv(priv))
@@ -1544,6 +1549,7 @@ static int enc28j60_probe(struct spi_device *spi)
 {
 	struct net_device *dev;
 	struct enc28j60_net *priv;
+	const void *macaddr;
 	int ret = 0;
 
 	if (netif_msg_drv(&debug))
@@ -1575,7 +1581,12 @@ static int enc28j60_probe(struct spi_device *spi)
 		ret = -EIO;
 		goto error_irq;
 	}
-	eth_hw_addr_random(dev);
+
+	macaddr = of_get_mac_address(spi->dev.of_node);
+	if (macaddr)
+		ether_addr_copy(dev->dev_addr, macaddr);
+	else
+		eth_hw_addr_random(dev);
 	enc28j60_set_hw_macaddr(dev);
 
 	/* Board setup must set the relevant edge trigger type;
@@ -1630,9 +1641,16 @@ static int enc28j60_remove(struct spi_device *spi)
 	return 0;
 }
 
+static const struct of_device_id enc28j60_dt_ids[] = {
+	{ .compatible = "microchip,enc28j60" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, enc28j60_dt_ids);
+
 static struct spi_driver enc28j60_driver = {
 	.driver = {
-		   .name = DRV_NAME,
+		.name = DRV_NAME,
+		.of_match_table = enc28j60_dt_ids,
 	 },
 	.probe = enc28j60_probe,
 	.remove = enc28j60_remove,