net: w5100: support W5200

This adds support for W5200 chip.

W5100 and W5200 have similar memory map although some of their offsets
are different.  The register access sequences between them are different
but w5100 driver has abstraction layer for difference bus interface
modes so it is easy to add W5200 support to w5100 and w5100-spi drivers.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Mike Sinkovsky <msink@permonline.ru>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/wiznet/Kconfig

@@ -70,7 +70,7 @@ config WIZNET_BUS_ANY
 endchoice
 
 config WIZNET_W5100_SPI
-	tristate "WIZnet W5100 Ethernet support for SPI mode"
+	tristate "WIZnet W5100/W5200 Ethernet support for SPI mode"
 	depends on WIZNET_BUS_ANY
 	depends on SPI
 	---help---

drivers/net/ethernet/wiznet/w5100-spi.c

 /*
- * Ethernet driver for the WIZnet W5100 chip.
+ * Ethernet driver for the WIZnet W5100/W5200 chip.
  *
  * Copyright (C) 2016 Akinobu Mita <akinobu.mita@gmail.com>
  *
  * Licensed under the GPL-2 or later.
+ *
+ * Datasheet:
+ * http://www.wiznet.co.kr/wp-content/uploads/wiznethome/Chip/W5100/Document/W5100_Datasheet_v1.2.6.pdf
+ * http://wiznethome.cafe24.com/wp-content/uploads/wiznethome/Chip/W5200/Documents/W5200_DS_V140E.pdf
  */
 
 #include <linux/kernel.h>
@@ -95,6 +99,7 @@ static int w5100_spi_writebulk(struct net_device *ndev, u16 addr, const u8 *buf,
 
 static const struct w5100_ops w5100_spi_ops = {
 	.may_sleep = true,
+	.chip_id = W5100,
 	.read = w5100_spi_read,
 	.write = w5100_spi_write,
 	.read16 = w5100_spi_read16,
@@ -103,10 +108,168 @@ static const struct w5100_ops w5100_spi_ops = {
 	.writebulk = w5100_spi_writebulk,
 };
 
+#define W5200_SPI_WRITE_OPCODE 0x80
+
+struct w5200_spi_priv {
+	/* Serialize access to cmd_buf */
+	struct mutex cmd_lock;
+
+	/* DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 */
+	u8 cmd_buf[4] ____cacheline_aligned;
+};
+
+static struct w5200_spi_priv *w5200_spi_priv(struct net_device *ndev)
+{
+	return w5100_ops_priv(ndev);
+}
+
+static int w5200_spi_init(struct net_device *ndev)
+{
+	struct w5200_spi_priv *spi_priv = w5200_spi_priv(ndev);
+
+	mutex_init(&spi_priv->cmd_lock);
+
+	return 0;
+}
+
+static int w5200_spi_read(struct net_device *ndev, u16 addr)
+{
+	struct spi_device *spi = to_spi_device(ndev->dev.parent);
+	u8 cmd[4] = { addr >> 8, addr & 0xff, 0, 1 };
+	u8 data;
+	int ret;
+
+	ret = spi_write_then_read(spi, cmd, sizeof(cmd), &data, 1);
+
+	return ret ? ret : data;
+}
+
+static int w5200_spi_write(struct net_device *ndev, u16 addr, u8 data)
+{
+	struct spi_device *spi = to_spi_device(ndev->dev.parent);
+	u8 cmd[5] = { addr >> 8, addr & 0xff, W5200_SPI_WRITE_OPCODE, 1, data };
+
+	return spi_write_then_read(spi, cmd, sizeof(cmd), NULL, 0);
+}
+
+static int w5200_spi_read16(struct net_device *ndev, u16 addr)
+{
+	struct spi_device *spi = to_spi_device(ndev->dev.parent);
+	u8 cmd[4] = { addr >> 8, addr & 0xff, 0, 2 };
+	__be16 data;
+	int ret;
+
+	ret = spi_write_then_read(spi, cmd, sizeof(cmd), &data, sizeof(data));
+
+	return ret ? ret : be16_to_cpu(data);
+}
+
+static int w5200_spi_write16(struct net_device *ndev, u16 addr, u16 data)
+{
+	struct spi_device *spi = to_spi_device(ndev->dev.parent);
+	u8 cmd[6] = {
+		addr >> 8, addr & 0xff,
+		W5200_SPI_WRITE_OPCODE, 2,
+		data >> 8, data & 0xff
+	};
+
+	return spi_write_then_read(spi, cmd, sizeof(cmd), NULL, 0);
+}
+
+static int w5200_spi_readbulk(struct net_device *ndev, u16 addr, u8 *buf,
+			      int len)
+{
+	struct spi_device *spi = to_spi_device(ndev->dev.parent);
+	struct w5200_spi_priv *spi_priv = w5200_spi_priv(ndev);
+	struct spi_transfer xfer[] = {
+		{
+			.tx_buf = spi_priv->cmd_buf,
+			.len = sizeof(spi_priv->cmd_buf),
+		},
+		{
+			.rx_buf = buf,
+			.len = len,
+		},
+	};
+	int ret;
+
+	mutex_lock(&spi_priv->cmd_lock);
+
+	spi_priv->cmd_buf[0] = addr >> 8;
+	spi_priv->cmd_buf[1] = addr;
+	spi_priv->cmd_buf[2] = len >> 8;
+	spi_priv->cmd_buf[3] = len;
+	ret = spi_sync_transfer(spi, xfer, ARRAY_SIZE(xfer));
+
+	mutex_unlock(&spi_priv->cmd_lock);
+
+	return ret;
+}
+
+static int w5200_spi_writebulk(struct net_device *ndev, u16 addr, const u8 *buf,
+			       int len)
+{
+	struct spi_device *spi = to_spi_device(ndev->dev.parent);
+	struct w5200_spi_priv *spi_priv = w5200_spi_priv(ndev);
+	struct spi_transfer xfer[] = {
+		{
+			.tx_buf = spi_priv->cmd_buf,
+			.len = sizeof(spi_priv->cmd_buf),
+		},
+		{
+			.tx_buf = buf,
+			.len = len,
+		},
+	};
+	int ret;
+
+	mutex_lock(&spi_priv->cmd_lock);
+
+	spi_priv->cmd_buf[0] = addr >> 8;
+	spi_priv->cmd_buf[1] = addr;
+	spi_priv->cmd_buf[2] = W5200_SPI_WRITE_OPCODE | (len >> 8);
+	spi_priv->cmd_buf[3] = len;
+	ret = spi_sync_transfer(spi, xfer, ARRAY_SIZE(xfer));
+
+	mutex_unlock(&spi_priv->cmd_lock);
+
+	return ret;
+}
+
+static const struct w5100_ops w5200_ops = {
+	.may_sleep = true,
+	.chip_id = W5200,
+	.read = w5200_spi_read,
+	.write = w5200_spi_write,
+	.read16 = w5200_spi_read16,
+	.write16 = w5200_spi_write16,
+	.readbulk = w5200_spi_readbulk,
+	.writebulk = w5200_spi_writebulk,
+	.init = w5200_spi_init,
+};
+
 static int w5100_spi_probe(struct spi_device *spi)
 {
-	return w5100_probe(&spi->dev, &w5100_spi_ops, 0, NULL, spi->irq,
-			   -EINVAL);
+	const struct spi_device_id *id = spi_get_device_id(spi);
+	const struct w5100_ops *ops;
+	int priv_size;
+
+	switch (id->driver_data) {
+	case W5100:
+		ops = &w5100_spi_ops;
+		priv_size = 0;
+		break;
+	case W5200:
+		ops = &w5200_ops;
+		priv_size = sizeof(struct w5200_spi_priv);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return w5100_probe(&spi->dev, ops, priv_size, NULL, spi->irq, -EINVAL);
 }
 
 static int w5100_spi_remove(struct spi_device *spi)
@@ -115,7 +278,8 @@ static int w5100_spi_remove(struct spi_device *spi)
 }
 
 static const struct spi_device_id w5100_spi_ids[] = {
-	{ "w5100", 0 },
+	{ "w5100", W5100 },
+	{ "w5200", W5200 },
 	{}
 };
 MODULE_DEVICE_TABLE(spi, w5100_spi_ids);
@@ -131,6 +295,6 @@ static struct spi_driver w5100_spi_driver = {
 };
 module_spi_driver(w5100_spi_driver);
 
-MODULE_DESCRIPTION("WIZnet W5100 Ethernet driver for SPI mode");
+MODULE_DESCRIPTION("WIZnet W5100/W5200 Ethernet driver for SPI mode");
 MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
 MODULE_LICENSE("GPL");

drivers/net/ethernet/wiznet/w5100.h

@@ -7,8 +7,14 @@
  * Licensed under the GPL-2 or later.
  */
 
+enum {
+	W5100,
+	W5200,
+};
+
 struct w5100_ops {
 	bool may_sleep;
+	int chip_id;
 	int (*read)(struct net_device *ndev, u16 addr);
 	int (*write)(struct net_device *ndev, u16 addr, u8 data);
 	int (*read16)(struct net_device *ndev, u16 addr);