diff options
Diffstat (limited to 'drivers/net/dsa/microchip/ksz9477_spi.c')
| -rw-r--r-- | drivers/net/dsa/microchip/ksz9477_spi.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/drivers/net/dsa/microchip/ksz9477_spi.c b/drivers/net/dsa/microchip/ksz9477_spi.c new file mode 100644 index 000000000000..d757ba151cb1 --- /dev/null +++ b/drivers/net/dsa/microchip/ksz9477_spi.c @@ -0,0 +1,177 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Microchip KSZ9477 series register access through SPI + * + * Copyright (C) 2017-2018 Microchip Technology Inc. + */ + +#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" +#include "ksz_spi.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 + +/* Enough to read all switch port registers. */ +#define SPI_TX_BUF_LEN 0x100 + +static int ksz9477_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 ksz9477_spi_write_reg(struct spi_device *spi, u32 reg, u8 *val, + unsigned int len) +{ + u32 *txbuf = (u32 *)val; + + *txbuf = reg & SPI_ADDR_MASK; + *txbuf |= (KS_SPIOP_WR << SPI_ADDR_SHIFT); + *txbuf <<= SPI_TURNAROUND_SHIFT; + *txbuf = cpu_to_be32(*txbuf); + + return spi_write(spi, txbuf, 4 + len); +} + +static int ksz_spi_read(struct ksz_device *dev, u32 reg, u8 *data, + unsigned int len) +{ + struct spi_device *spi = dev->priv; + + return ksz9477_spi_read_reg(spi, reg, data, len); +} + +static int ksz_spi_write(struct ksz_device *dev, u32 reg, void *data, + unsigned int len) +{ + struct spi_device *spi = dev->priv; + + if (len > SPI_TX_BUF_LEN) + len = SPI_TX_BUF_LEN; + memcpy(&dev->txbuf[4], data, len); + return ksz9477_spi_write_reg(spi, reg, dev->txbuf, len); +} + +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_write24(struct ksz_device *dev, u32 reg, u32 value) +{ + /* make it to big endian 24bit from MSB */ + value <<= 8; + value = cpu_to_be32(value); + return ksz_spi_write(dev, reg, &value, 3); +} + +static const struct ksz_io_ops ksz9477_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, + .get = ksz_spi_get, + .set = ksz_spi_set, +}; + +static int ksz9477_spi_probe(struct spi_device *spi) +{ + struct ksz_device *dev; + int ret; + + dev = ksz_switch_alloc(&spi->dev, &ksz9477_spi_ops, spi); + if (!dev) + return -ENOMEM; + + if (spi->dev.platform_data) + dev->pdata = spi->dev.platform_data; + + dev->txbuf = devm_kzalloc(dev->dev, 4 + SPI_TX_BUF_LEN, GFP_KERNEL); + + ret = ksz9477_switch_register(dev); + + /* Main DSA driver may not be started yet. */ + if (ret) + return ret; + + spi_set_drvdata(spi, dev); + + return 0; +} + +static int ksz9477_spi_remove(struct spi_device *spi) +{ + struct ksz_device *dev = spi_get_drvdata(spi); + + if (dev) + ksz_switch_remove(dev); + + return 0; +} + +static void ksz9477_spi_shutdown(struct spi_device *spi) +{ + struct ksz_device *dev = spi_get_drvdata(spi); + + if (dev && dev->dev_ops->shutdown) + dev->dev_ops->shutdown(dev); +} + +static const struct of_device_id ksz9477_dt_ids[] = { + { .compatible = "microchip,ksz9477" }, + { .compatible = "microchip,ksz9897" }, + {}, +}; +MODULE_DEVICE_TABLE(of, ksz9477_dt_ids); + +static struct spi_driver ksz9477_spi_driver = { + .driver = { + .name = "ksz9477-switch", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(ksz9477_dt_ids), + }, + .probe = ksz9477_spi_probe, + .remove = ksz9477_spi_remove, + .shutdown = ksz9477_spi_shutdown, +}; + +module_spi_driver(ksz9477_spi_driver); + +MODULE_AUTHOR("Woojung Huh <Woojung.Huh@microchip.com>"); +MODULE_DESCRIPTION("Microchip KSZ9477 Series Switch SPI access Driver"); +MODULE_LICENSE("GPL"); |