1 // SPDX-License-Identifier: GPL-2.0
3 * Microchip KSZ9477 series register access through SPI
5 * Copyright (C) 2017-2019 Microchip Technology Inc.
8 #include <asm/unaligned.h>
10 #include <linux/delay.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/spi/spi.h>
18 /* SPI frame opcodes */
22 #define SPI_ADDR_SHIFT 24
23 #define SPI_ADDR_MASK (BIT(SPI_ADDR_SHIFT) - 1)
24 #define SPI_TURNAROUND_SHIFT 5
26 /* Enough to read all switch port registers. */
27 #define SPI_TX_BUF_LEN 0x100
29 static int ksz9477_spi_read_reg(struct spi_device *spi, u32 reg, u8 *val,
35 txbuf = reg & SPI_ADDR_MASK;
36 txbuf |= KS_SPIOP_RD << SPI_ADDR_SHIFT;
37 txbuf <<= SPI_TURNAROUND_SHIFT;
38 txbuf = cpu_to_be32(txbuf);
40 ret = spi_write_then_read(spi, &txbuf, 4, val, len);
44 static int ksz9477_spi_write_reg(struct spi_device *spi, u32 reg, u8 *val,
47 u32 *txbuf = (u32 *)val;
49 *txbuf = reg & SPI_ADDR_MASK;
50 *txbuf |= (KS_SPIOP_WR << SPI_ADDR_SHIFT);
51 *txbuf <<= SPI_TURNAROUND_SHIFT;
52 *txbuf = cpu_to_be32(*txbuf);
54 return spi_write(spi, txbuf, 4 + len);
57 static int ksz_spi_read(struct ksz_device *dev, u32 reg, u8 *data,
60 struct spi_device *spi = dev->priv;
62 return ksz9477_spi_read_reg(spi, reg, data, len);
65 static int ksz_spi_write(struct ksz_device *dev, u32 reg, void *data,
68 struct spi_device *spi = dev->priv;
70 if (len > SPI_TX_BUF_LEN)
72 memcpy(&dev->txbuf[4], data, len);
73 return ksz9477_spi_write_reg(spi, reg, dev->txbuf, len);
76 static int ksz_spi_read24(struct ksz_device *dev, u32 reg, u32 *val)
81 ret = ksz_spi_read(dev, reg, (u8 *)val, 3);
83 *val = be32_to_cpu(*val);
84 /* convert to 24bit */
91 static int ksz_spi_write24(struct ksz_device *dev, u32 reg, u32 value)
93 /* make it to big endian 24bit from MSB */
95 value = cpu_to_be32(value);
96 return ksz_spi_write(dev, reg, &value, 3);
99 static const struct ksz_io_ops ksz9477_spi_ops = {
100 .read8 = ksz_spi_read8,
101 .read16 = ksz_spi_read16,
102 .read24 = ksz_spi_read24,
103 .read32 = ksz_spi_read32,
104 .write8 = ksz_spi_write8,
105 .write16 = ksz_spi_write16,
106 .write24 = ksz_spi_write24,
107 .write32 = ksz_spi_write32,
112 static int ksz9477_spi_probe(struct spi_device *spi)
114 struct ksz_device *dev;
117 dev = ksz_switch_alloc(&spi->dev, &ksz9477_spi_ops, spi);
121 if (spi->dev.platform_data)
122 dev->pdata = spi->dev.platform_data;
124 dev->txbuf = devm_kzalloc(dev->dev, 4 + SPI_TX_BUF_LEN, GFP_KERNEL);
126 ret = ksz9477_switch_register(dev);
128 /* Main DSA driver may not be started yet. */
132 spi_set_drvdata(spi, dev);
137 static int ksz9477_spi_remove(struct spi_device *spi)
139 struct ksz_device *dev = spi_get_drvdata(spi);
142 ksz_switch_remove(dev);
147 static void ksz9477_spi_shutdown(struct spi_device *spi)
149 struct ksz_device *dev = spi_get_drvdata(spi);
151 if (dev && dev->dev_ops->shutdown)
152 dev->dev_ops->shutdown(dev);
155 static const struct of_device_id ksz9477_dt_ids[] = {
156 { .compatible = "microchip,ksz9477" },
157 { .compatible = "microchip,ksz9897" },
158 { .compatible = "microchip,ksz9893" },
159 { .compatible = "microchip,ksz9563" },
162 MODULE_DEVICE_TABLE(of, ksz9477_dt_ids);
164 static struct spi_driver ksz9477_spi_driver = {
166 .name = "ksz9477-switch",
167 .owner = THIS_MODULE,
168 .of_match_table = of_match_ptr(ksz9477_dt_ids),
170 .probe = ksz9477_spi_probe,
171 .remove = ksz9477_spi_remove,
172 .shutdown = ksz9477_spi_shutdown,
175 module_spi_driver(ksz9477_spi_driver);
177 MODULE_AUTHOR("Woojung Huh <Woojung.Huh@microchip.com>");
178 MODULE_DESCRIPTION("Microchip KSZ9477 Series Switch SPI access Driver");
179 MODULE_LICENSE("GPL");