net: dsa: vsc73xx: Split vsc73xx driver

This driver (currently) only takes control of the switch chip over
SPI and configures it to route packages around when connected to a
CPU port. But Vitesse chip support also parallel interface.

This patch split driver into two parts: core and spi. It is required
for add support to another managing interface.

Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 203 insertions, 0 deletions

diff --git a/drivers/net/dsa/vitesse-vsc73xx-spi.c b/drivers/net/dsa/vitesse-vsc73xx-spi.c
new file mode 100644
index 000000000000..e73c8fcddc9f
--- /dev/null
+++ b/drivers/net/dsa/vitesse-vsc73xx-spi.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0
+/* DSA driver for:
+ * Vitesse VSC7385 SparX-G5 5+1-port Integrated Gigabit Ethernet Switch
+ * Vitesse VSC7388 SparX-G8 8-port Integrated Gigabit Ethernet Switch
+ * Vitesse VSC7395 SparX-G5e 5+1-port Integrated Gigabit Ethernet Switch
+ * Vitesse VSC7398 SparX-G8e 8-port Integrated Gigabit Ethernet Switch
+ *
+ * This driver takes control of the switch chip over SPI and
+ * configures it to route packages around when connected to a CPU port.
+ *
+ * Copyright (C) 2018 Linus Wallej <linus.walleij@linaro.org>
+ * Includes portions of code from the firmware uploader by:
+ * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/spi/spi.h>
+
+#include "vitesse-vsc73xx.h"
+
+#define VSC73XX_CMD_SPI_MODE_READ		0
+#define VSC73XX_CMD_SPI_MODE_WRITE		1
+#define VSC73XX_CMD_SPI_MODE_SHIFT		4
+#define VSC73XX_CMD_SPI_BLOCK_SHIFT		5
+#define VSC73XX_CMD_SPI_BLOCK_MASK		0x7
+#define VSC73XX_CMD_SPI_SUBBLOCK_MASK		0xf
+
+/**
+ * struct vsc73xx_spi - VSC73xx SPI state container
+ */
+struct vsc73xx_spi {
+	struct spi_device	*spi;
+	struct mutex		lock; /* Protects SPI traffic */
+	struct vsc73xx		vsc;
+};
+
+static const struct vsc73xx_ops vsc73xx_spi_ops;
+
+static u8 vsc73xx_make_addr(u8 mode, u8 block, u8 subblock)
+{
+	u8 ret;
+
+	ret =
+	    (block & VSC73XX_CMD_SPI_BLOCK_MASK) << VSC73XX_CMD_SPI_BLOCK_SHIFT;
+	ret |= (mode & 1) << VSC73XX_CMD_SPI_MODE_SHIFT;
+	ret |= subblock & VSC73XX_CMD_SPI_SUBBLOCK_MASK;
+
+	return ret;
+}
+
+static int vsc73xx_spi_read(struct vsc73xx *vsc, u8 block, u8 subblock, u8 reg,
+			    u32 *val)
+{
+	struct vsc73xx_spi *vsc_spi = vsc->priv;
+	struct spi_transfer t[2];
+	struct spi_message m;
+	u8 cmd[4];
+	u8 buf[4];
+	int ret;
+
+	if (!vsc73xx_is_addr_valid(block, subblock))
+		return -EINVAL;
+
+	spi_message_init(&m);
+
+	memset(&t, 0, sizeof(t));
+
+	t[0].tx_buf = cmd;
+	t[0].len = sizeof(cmd);
+	spi_message_add_tail(&t[0], &m);
+
+	t[1].rx_buf = buf;
+	t[1].len = sizeof(buf);
+	spi_message_add_tail(&t[1], &m);
+
+	cmd[0] = vsc73xx_make_addr(VSC73XX_CMD_SPI_MODE_READ, block, subblock);
+	cmd[1] = reg;
+	cmd[2] = 0;
+	cmd[3] = 0;
+
+	mutex_lock(&vsc_spi->lock);
+	ret = spi_sync(vsc_spi->spi, &m);
+	mutex_unlock(&vsc_spi->lock);
+
+	if (ret)
+		return ret;
+
+	*val = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
+
+	return 0;
+}
+
+static int vsc73xx_spi_write(struct vsc73xx *vsc, u8 block, u8 subblock, u8 reg,
+			     u32 val)
+{
+	struct vsc73xx_spi *vsc_spi = vsc->priv;
+	struct spi_transfer t[2];
+	struct spi_message m;
+	u8 cmd[2];
+	u8 buf[4];
+	int ret;
+
+	if (!vsc73xx_is_addr_valid(block, subblock))
+		return -EINVAL;
+
+	spi_message_init(&m);
+
+	memset(&t, 0, sizeof(t));
+
+	t[0].tx_buf = cmd;
+	t[0].len = sizeof(cmd);
+	spi_message_add_tail(&t[0], &m);
+
+	t[1].tx_buf = buf;
+	t[1].len = sizeof(buf);
+	spi_message_add_tail(&t[1], &m);
+
+	cmd[0] = vsc73xx_make_addr(VSC73XX_CMD_SPI_MODE_WRITE, block, subblock);
+	cmd[1] = reg;
+
+	buf[0] = (val >> 24) & 0xff;
+	buf[1] = (val >> 16) & 0xff;
+	buf[2] = (val >> 8) & 0xff;
+	buf[3] = val & 0xff;
+
+	mutex_lock(&vsc_spi->lock);
+	ret = spi_sync(vsc_spi->spi, &m);
+	mutex_unlock(&vsc_spi->lock);
+
+	return ret;
+}
+
+static int vsc73xx_spi_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct vsc73xx_spi *vsc_spi;
+	int ret;
+
+	vsc_spi = devm_kzalloc(dev, sizeof(*vsc_spi), GFP_KERNEL);
+	if (!vsc_spi)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, vsc_spi);
+	vsc_spi->spi = spi_dev_get(spi);
+	vsc_spi->vsc.dev = dev;
+	vsc_spi->vsc.priv = vsc_spi;
+	vsc_spi->vsc.ops = &vsc73xx_spi_ops;
+	mutex_init(&vsc_spi->lock);
+
+	spi->mode = SPI_MODE_0;
+	spi->bits_per_word = 8;
+	ret = spi_setup(spi);
+	if (ret < 0) {
+		dev_err(dev, "spi setup failed.\n");
+		return ret;
+	}
+
+	return vsc73xx_probe(&vsc_spi->vsc);
+}
+
+static int vsc73xx_spi_remove(struct spi_device *spi)
+{
+	struct vsc73xx_spi *vsc_spi = spi_get_drvdata(spi);
+
+	return vsc73xx_remove(&vsc_spi->vsc);
+}
+
+static const struct vsc73xx_ops vsc73xx_spi_ops = {
+	.read = vsc73xx_spi_read,
+	.write = vsc73xx_spi_write,
+};
+
+static const struct of_device_id vsc73xx_of_match[] = {
+	{
+		.compatible = "vitesse,vsc7385",
+	},
+	{
+		.compatible = "vitesse,vsc7388",
+	},
+	{
+		.compatible = "vitesse,vsc7395",
+	},
+	{
+		.compatible = "vitesse,vsc7398",
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, vsc73xx_of_match);
+
+static struct spi_driver vsc73xx_spi_driver = {
+	.probe = vsc73xx_spi_probe,
+	.remove = vsc73xx_spi_remove,
+	.driver = {
+		.name = "vsc73xx-spi",
+		.of_match_table = vsc73xx_of_match,
+	},
+};
+module_spi_driver(vsc73xx_spi_driver);
+
+MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
+MODULE_DESCRIPTION("Vitesse VSC7385/7388/7395/7398 SPI driver");
+MODULE_LICENSE("GPL v2");