[PATCH] net: add MMIO Register MDIO MUX driver

[Neil Armstrong]

On 25/02/2021 20:36, Ramon Fried wrote:
> On Wed, Feb 24, 2021 at 4:02 PM Neil Armstrong <narmstrong at baylibre.com> wrote:
>>
>> Add support for MMIO register MDIO muxes based on the Linux mdio-mux-mmioreg driver.
>>
>> Signed-off-by: Neil Armstrong <narmstrong at baylibre.com>
>> ---
>>  drivers/net/Kconfig            |   7 ++
>>  drivers/net/Makefile           |   1 +
>>  drivers/net/mdio_mux_mmioreg.c | 129 +++++++++++++++++++++++++++++++++
>>  3 files changed, 137 insertions(+)
>>  create mode 100644 drivers/net/mdio_mux_mmioreg.c
>>
>> diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
>> index 0e84c22b50..41fa2fe566 100644
>> --- a/drivers/net/Kconfig
>> +++ b/drivers/net/Kconfig
>> @@ -790,4 +790,11 @@ config FSL_LS_MDIO
>>           This driver supports the MDIO bus found on the Fman 10G Ethernet MACs and
>>           on the mEMAC (which supports both Clauses 22 and 45).
>>
>> +config MDIO_MUX_MMIOREG
>> +       bool "MDIO MUX accessed as a MMIO register access"
>> +       depends on DM_MDIO_MUX
>> +       help
>> +         This driver is used for MDIO muxes driven by writing to a register in
>> +         the MMIO physical memory.
>> +
>>  endif # NETDEVICES
>> diff --git a/drivers/net/Makefile b/drivers/net/Makefile
>> index a19511aaa7..511c87c3a5 100644
>> --- a/drivers/net/Makefile
>> +++ b/drivers/net/Makefile
>> @@ -43,6 +43,7 @@ obj-$(CONFIG_MACB) += macb.o
>>  obj-$(CONFIG_MCFFEC) += mcffec.o mcfmii.o
>>  obj-$(CONFIG_MDIO_IPQ4019) += mdio-ipq4019.o
>>  obj-$(CONFIG_MDIO_MUX_I2CREG) += mdio_mux_i2creg.o
>> +obj-$(CONFIG_MDIO_MUX_MMIOREG) += mdio_mux_mmioreg.o
>>  obj-$(CONFIG_MDIO_MUX_SANDBOX) += mdio_mux_sandbox.o
>>  obj-$(CONFIG_MPC8XX_FEC) += mpc8xx_fec.o
>>  obj-$(CONFIG_MT7620_ETH) += mt7620-eth.o
>> diff --git a/drivers/net/mdio_mux_mmioreg.c b/drivers/net/mdio_mux_mmioreg.c
>> new file mode 100644
>> index 0000000000..e1a23e40a2
>> --- /dev/null
>> +++ b/drivers/net/mdio_mux_mmioreg.c
>> @@ -0,0 +1,129 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * (C) Copyright 2021 BayLibre, SAS
>> + * Author: Neil Armstrong <narmstrong at baylibre.com>
>> + *
>> + * Based on linux/drivers/net/phy/mdio-mux-mmioreg.c :
>> + *   Copyright 2012 Freescale Semiconductor, Inc.
>> + */
>> +
>> +#include <dm.h>
>> +#include <errno.h>
>> +#include <log.h>
>> +#include <miiphy.h>
>> +#include <linux/io.h>
>> +
>> +struct mdio_mux_mmioreg_priv {
>> +       struct udevice *chip;
>> +       phys_addr_t phys;
>> +       unsigned int iosize;
>> +       unsigned int mask;
>> +};
>> +
>> +static int mdio_mux_mmioreg_select(struct udevice *mux, int cur, int sel)
>> +{
>> +       struct mdio_mux_mmioreg_priv *priv = dev_get_priv(mux);
>> +
>> +       debug("%s: %x -> %x\n", __func__, (u32)cur, (u32)sel);
>> +
>> +       /* if last selection didn't change we're good to go */
>> +       if (cur == sel)
>> +               return 0;
>> +
>> +       switch (priv->iosize) {
>> +       case sizeof(u8): {
>> +               u8 x, y;
>> +
>> +               x = ioread8((void *)priv->phys);
>> +               y = (x & ~priv->mask) | (u32)sel;
>> +               if (x != y) {
>> +                       iowrite8((x & ~priv->mask) | sel, (void *)priv->phys);
>> +                       debug("%s: %02x -> %02x\n", __func__, x, y);
>> +               }
>> +
>> +               break;
>> +       }
>> +       case sizeof(u16): {
>> +               u16 x, y;
>> +
>> +               x = ioread16((void *)priv->phys);
>> +               y = (x & ~priv->mask) | (u32)sel;
>> +               if (x != y) {
>> +                       iowrite16((x & ~priv->mask) | sel, (void *)priv->phys);
>> +                       debug("%s: %04x -> %04x\n", __func__, x, y);
>> +               }
>> +
>> +               break;
>> +       }
>> +       case sizeof(u32): {
>> +               u32 x, y;
>> +
>> +               x = ioread32((void *)priv->phys);
>> +               y = (x & ~priv->mask) | (u32)sel;
>> +               if (x != y) {
>> +                       iowrite32((x & ~priv->mask) | sel, (void *)priv->phys);
>> +                       debug("%s: %08x -> %08x\n", __func__, x, y);
>> +               }
>> +
>> +               break;
>> +       }
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static const struct mdio_mux_ops mdio_mux_mmioreg_ops = {
>> +       .select = mdio_mux_mmioreg_select,
>> +};
>> +
>> +static int mdio_mux_mmioreg_probe(struct udevice *dev)
>> +{
>> +       struct mdio_mux_mmioreg_priv *priv = dev_get_priv(dev);
>> +       phys_addr_t reg_base, reg_size;
>> +       u32 reg_mask;
>> +       int err;
>> +
>> +       reg_base = ofnode_get_addr_size_index(dev_ofnode(dev), 0, &reg_size);
>> +       if (reg_base == FDT_ADDR_T_NONE)
>> +               return -EINVAL;
>> +
>> +       if (reg_size != sizeof(u8) &&
>> +           reg_size != sizeof(u16) &&
>> +           reg_size != sizeof(u32)) {
>> +               printf("%s: only 8/16/32-bit registers are supported\n", __func__);
>> +               return -EINVAL;
>> +       }
>> +
>> +       err = dev_read_u32(dev, "mux-mask", &reg_mask);
>> +       if (err) {
>> +               debug("%s: error reading mux-mask property\n", __func__);
>> +               return err;
>> +       }
>> +
>> +       if (reg_mask >= BIT(reg_size * 8)) {
>> +               printf("%s: mask doesn't fix in register width\n", __func__);
>> +               return -EINVAL;
>> +       }
>> +
>> +       priv->phys = reg_base;
>> +       priv->iosize = reg_size;
>> +       priv->mask = reg_mask;
>> +
>> +       debug("%s: %llx@%lld / %x\n", __func__, reg_base, reg_size, reg_mask);
>> +
>> +       return 0;
>> +}
>> +
>> +static const struct udevice_id mdio_mux_mmioreg_ids[] = {
>> +       { .compatible = "mdio-mux-mmioreg" },
>> +       { }
>> +};
>> +
>> +U_BOOT_DRIVER(mdio_mux_mmioreg) = {
>> +       .name           = "mdio_mux_mmioreg",
>> +       .id             = UCLASS_MDIO_MUX,
>> +       .of_match       = mdio_mux_mmioreg_ids,
>> +       .probe          = mdio_mux_mmioreg_probe,
>> +       .ops            = &mdio_mux_mmioreg_ops,
>> +       .priv_auto      = sizeof(struct mdio_mux_mmioreg_priv),
>> +};
>> --
>> 2.25.1
>>
> Reviewed-by: Ramon Fried <rfried.dev at gmail.com>
> 

Thanks !

Applied to u-boot-amlogic-next