drivers/net/ksz8864rmn: add driver for Micrel KSZ8864RMN Ethernet Switch

It starts the switch and provides basic access to the registers.

This driver could also work with some other Micrel switches, possibly
with some small changes.

Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

3 files changed, 199 insertions, 0 deletions

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 3c5f729db3..dac1eb927f 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -125,5 +125,12 @@ config DRIVER_NET_GIANFAR
 
 source "drivers/net/usb/Kconfig"
 
+config DRIVER_NET_MICREL
+	depends on SPI
+	bool "Micrel KSZ8864RMN Ethernet Switch driver"
+	help
+	  This option enables support for enabling the Micrel
+	  KSZ8864RMN Ethernet Switch over SPI.
+
 endmenu
 
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index 4d960e856f..951a2208b4 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -15,3 +15,4 @@ obj-$(CONFIG_DRIVER_NET_TSE)		+= altera_tse.o
 obj-$(CONFIG_DRIVER_NET_KS8851_MLL)	+= ks8851_mll.o
 obj-$(CONFIG_DRIVER_NET_DESIGNWARE)	+= designware.o
 obj-$(CONFIG_DRIVER_NET_GIANFAR)	+= gianfar.o
+obj-$(CONFIG_DRIVER_NET_MICREL)		+= ksz8864rmn.o
diff --git a/drivers/net/ksz8864rmn.c b/drivers/net/ksz8864rmn.c
new file mode 100644
index 0000000000..5845960f6c
--- /dev/null
+++ b/drivers/net/ksz8864rmn.c
@@ -0,0 +1,191 @@
+/*
+ * Copyright (C) 2012 Jan Luebbe, Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+#include <common.h>
+#include <init.h>
+#include <driver.h>
+#include <spi/spi.h>
+#include <errno.h>
+
+#define REG_ID0			0x00
+#define REG_ID1			0x01
+
+#define REG_GC00		0x02
+#define REG_GC01		0x03
+#define REG_GC02		0x04
+#define REG_GC03		0x05
+#define REG_GC04		0x06
+#define REG_GC05		0x07
+#define REG_GC06		0x08
+#define REG_GC07		0x09
+#define REG_GC08		0x0a
+#define REG_GC09		0x0b
+#define REG_GC10		0x0c
+#define REG_GC11		0x0d
+
+#define REG_PSTAT1(p)		(0x10 * p + 0xe)
+#define REG_PSTAT2(p)		(0x10 * p + 0xf)
+
+#define CMD_WRITE		0x02
+#define CMD_READ		0x03
+
+struct micrel_switch_priv {
+	struct cdev             cdev;
+	struct spi_device       *spi;
+};
+
+static int micrel_switch_read_reg(struct spi_device *spi, uint8_t reg)
+{
+	uint8_t tx[2];
+	uint8_t rx[1];
+	int ret;
+
+	tx[0] = CMD_READ;
+	tx[1] = reg;
+
+	ret = spi_write_then_read(spi, tx, 2, rx, 1);
+	if (ret < 0)
+		return ret;
+
+	return rx[0];
+}
+
+static void micrel_switch_write_reg(struct spi_device *spi, uint8_t reg, uint8_t val)
+{
+	uint8_t tx[3];
+
+	tx[0] = CMD_WRITE;
+	tx[1] = reg;
+	tx[2] = val;
+
+	spi_write_then_read(spi, tx, 3, NULL, 0);
+}
+
+static int micrel_switch_enable_set(struct device_d *dev, struct param_d *param,
+		const char *val)
+{
+	struct spi_device *spi = (struct spi_device *)dev->type_data;
+	int enable;
+	char *new;
+
+	if (!val)
+		return dev_param_set_generic(dev, param, NULL);
+
+	enable = simple_strtoul(val, NULL, 0);
+
+	if (enable) {
+		micrel_switch_write_reg(spi, REG_ID1, 1);
+		new = "1";
+	} else {
+		micrel_switch_write_reg(spi, REG_ID1, 0);
+		new = "0";
+	}
+
+	dev_param_set_generic(dev, param, new);
+
+	return 0;
+}
+
+static ssize_t micel_switch_read(struct cdev *cdev, void *_buf, size_t count, loff_t offset, ulong flags)
+{
+	int i, ret;
+	uint8_t *buf = _buf;
+	struct micrel_switch_priv *priv = cdev->priv;
+
+	for (i = 0; i < count; i++) {
+		ret = micrel_switch_read_reg(priv->spi, offset);
+		if (ret < 0)
+			return ret;
+		*buf = ret;
+		buf++;
+		offset++;
+	}
+
+	return count;
+}
+
+static ssize_t micel_switch_write(struct cdev *cdev, const void *_buf, size_t count, loff_t offset, ulong flags)
+{
+	int i;
+	const uint8_t *buf = _buf;
+	struct micrel_switch_priv *priv = cdev->priv;
+
+	for (i = 0; i < count; i++) {
+		micrel_switch_write_reg(priv->spi, offset, *buf);
+		buf++;
+		offset++;
+	}
+
+	return count;
+}
+
+static struct file_operations micrel_switch_ops = {
+	.read  = micel_switch_read,
+	.write = micel_switch_write,
+	.lseek = dev_lseek_default,
+};
+
+static int micrel_switch_probe(struct device_d *dev)
+{
+	struct micrel_switch_priv *priv;
+	int ret = 0;
+
+	priv = xzalloc(sizeof(*priv));
+
+	dev->priv = priv;
+
+	priv->spi = (struct spi_device *)dev->type_data;
+	priv->spi->mode = SPI_MODE_0;
+	priv->spi->bits_per_word = 8;
+
+	ret = micrel_switch_read_reg(priv->spi, REG_ID0);
+	if (ret < 0) {
+		dev_err(&priv->spi->dev, "failed to read device id\n");
+		return ret;
+	}
+	if (ret != 0x95) {
+		dev_err(&priv->spi->dev, "unknown device id: %02x\n", ret);
+		return -ENODEV;
+	}
+
+	priv->cdev.name = asprintf("switch%d", dev->id);
+	priv->cdev.size = 256;
+	priv->cdev.ops = &micrel_switch_ops;
+	priv->cdev.priv = priv;
+	priv->cdev.dev = dev;
+	devfs_create(&priv->cdev);
+
+	dev_add_param(dev, "enable", micrel_switch_enable_set, NULL, 0);
+	dev_set_param(dev, "enable", "1");
+
+	return 0;
+}
+
+static struct driver_d micrel_switch_driver = {
+	.name  = "ksz8864rmn",
+	.probe = micrel_switch_probe,
+};
+
+static int micrel_switch_init(void)
+{
+	spi_register_driver(&micrel_switch_driver);
+	return 0;
+}
+device_initcall(micrel_switch_init);