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path: root/drivers/net/dsa/microchip/ksz_spi.c
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Diffstat (limited to 'drivers/net/dsa/microchip/ksz_spi.c')
-rw-r--r--drivers/net/dsa/microchip/ksz_spi.c216
1 files changed, 216 insertions, 0 deletions
diff --git a/drivers/net/dsa/microchip/ksz_spi.c b/drivers/net/dsa/microchip/ksz_spi.c
new file mode 100644
index 000000000000..c51946983bed
--- /dev/null
+++ b/drivers/net/dsa/microchip/ksz_spi.c
@@ -0,0 +1,216 @@
+/*
+ * Microchip KSZ series register access through SPI
+ *
+ * Copyright (C) 2017
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <asm/unaligned.h>
+
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+
+#include "ksz_priv.h"
+
+/* SPI frame opcodes */
+#define KS_SPIOP_RD 3
+#define KS_SPIOP_WR 2
+
+#define SPI_ADDR_SHIFT 24
+#define SPI_ADDR_MASK (BIT(SPI_ADDR_SHIFT) - 1)
+#define SPI_TURNAROUND_SHIFT 5
+
+static int ksz_spi_read_reg(struct spi_device *spi, u32 reg, u8 *val,
+ unsigned int len)
+{
+ u32 txbuf;
+ int ret;
+
+ txbuf = reg & SPI_ADDR_MASK;
+ txbuf |= KS_SPIOP_RD << SPI_ADDR_SHIFT;
+ txbuf <<= SPI_TURNAROUND_SHIFT;
+ txbuf = cpu_to_be32(txbuf);
+
+ ret = spi_write_then_read(spi, &txbuf, 4, val, len);
+ return ret;
+}
+
+static int ksz_spi_read(struct ksz_device *dev, u32 reg, u8 *data,
+ unsigned int len)
+{
+ struct spi_device *spi = dev->priv;
+
+ return ksz_spi_read_reg(spi, reg, data, len);
+}
+
+static int ksz_spi_read8(struct ksz_device *dev, u32 reg, u8 *val)
+{
+ return ksz_spi_read(dev, reg, val, 1);
+}
+
+static int ksz_spi_read16(struct ksz_device *dev, u32 reg, u16 *val)
+{
+ int ret = ksz_spi_read(dev, reg, (u8 *)val, 2);
+
+ if (!ret)
+ *val = be16_to_cpu(*val);
+
+ return ret;
+}
+
+static int ksz_spi_read24(struct ksz_device *dev, u32 reg, u32 *val)
+{
+ int ret;
+
+ *val = 0;
+ ret = ksz_spi_read(dev, reg, (u8 *)val, 3);
+ if (!ret) {
+ *val = be32_to_cpu(*val);
+ /* convert to 24bit */
+ *val >>= 8;
+ }
+
+ return ret;
+}
+
+static int ksz_spi_read32(struct ksz_device *dev, u32 reg, u32 *val)
+{
+ int ret = ksz_spi_read(dev, reg, (u8 *)val, 4);
+
+ if (!ret)
+ *val = be32_to_cpu(*val);
+
+ return ret;
+}
+
+static int ksz_spi_write_reg(struct spi_device *spi, u32 reg, u8 *val,
+ unsigned int len)
+{
+ u32 txbuf;
+ u8 data[12];
+ int i;
+
+ txbuf = reg & SPI_ADDR_MASK;
+ txbuf |= (KS_SPIOP_WR << SPI_ADDR_SHIFT);
+ txbuf <<= SPI_TURNAROUND_SHIFT;
+ txbuf = cpu_to_be32(txbuf);
+
+ data[0] = txbuf & 0xFF;
+ data[1] = (txbuf & 0xFF00) >> 8;
+ data[2] = (txbuf & 0xFF0000) >> 16;
+ data[3] = (txbuf & 0xFF000000) >> 24;
+ for (i = 0; i < len; i++)
+ data[i + 4] = val[i];
+
+ return spi_write(spi, &data, 4 + len);
+}
+
+static int ksz_spi_write8(struct ksz_device *dev, u32 reg, u8 value)
+{
+ struct spi_device *spi = dev->priv;
+
+ return ksz_spi_write_reg(spi, reg, &value, 1);
+}
+
+static int ksz_spi_write16(struct ksz_device *dev, u32 reg, u16 value)
+{
+ struct spi_device *spi = dev->priv;
+
+ value = cpu_to_be16(value);
+ return ksz_spi_write_reg(spi, reg, (u8 *)&value, 2);
+}
+
+static int ksz_spi_write24(struct ksz_device *dev, u32 reg, u32 value)
+{
+ struct spi_device *spi = dev->priv;
+
+ /* make it to big endian 24bit from MSB */
+ value <<= 8;
+ value = cpu_to_be32(value);
+ return ksz_spi_write_reg(spi, reg, (u8 *)&value, 3);
+}
+
+static int ksz_spi_write32(struct ksz_device *dev, u32 reg, u32 value)
+{
+ struct spi_device *spi = dev->priv;
+
+ value = cpu_to_be32(value);
+ return ksz_spi_write_reg(spi, reg, (u8 *)&value, 4);
+}
+
+static const struct ksz_io_ops ksz_spi_ops = {
+ .read8 = ksz_spi_read8,
+ .read16 = ksz_spi_read16,
+ .read24 = ksz_spi_read24,
+ .read32 = ksz_spi_read32,
+ .write8 = ksz_spi_write8,
+ .write16 = ksz_spi_write16,
+ .write24 = ksz_spi_write24,
+ .write32 = ksz_spi_write32,
+};
+
+static int ksz_spi_probe(struct spi_device *spi)
+{
+ struct ksz_device *dev;
+ int ret;
+
+ dev = ksz_switch_alloc(&spi->dev, &ksz_spi_ops, spi);
+ if (!dev)
+ return -ENOMEM;
+
+ if (spi->dev.platform_data)
+ dev->pdata = spi->dev.platform_data;
+
+ ret = ksz_switch_register(dev);
+ if (ret)
+ return ret;
+
+ spi_set_drvdata(spi, dev);
+
+ return 0;
+}
+
+static int ksz_spi_remove(struct spi_device *spi)
+{
+ struct ksz_device *dev = spi_get_drvdata(spi);
+
+ if (dev)
+ ksz_switch_remove(dev);
+
+ return 0;
+}
+
+static const struct of_device_id ksz_dt_ids[] = {
+ { .compatible = "microchip,ksz9477" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ksz_dt_ids);
+
+static struct spi_driver ksz_spi_driver = {
+ .driver = {
+ .name = "ksz9477-switch",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(ksz_dt_ids),
+ },
+ .probe = ksz_spi_probe,
+ .remove = ksz_spi_remove,
+};
+
+module_spi_driver(ksz_spi_driver);
+
+MODULE_AUTHOR("Woojung Huh <Woojung.Huh@microchip.com>");
+MODULE_DESCRIPTION("Microchip KSZ Series Switch SPI access Driver");
+MODULE_LICENSE("GPL");