Re: [PATCH net-next v5 5/5] net: phy: add driver for built-in 2.5G ethernet PHY on MT7988

["SkyLake Huang (黃啟澤)" <SkyLake.Huang@mediatek.com>]

On Sat, 2024-06-01 at 13:51 +0100, Simon Horman wrote:
>  	 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
>  On Thu, May 30, 2024 at 11:48:44AM +0800, Sky Huang wrote:
> > From: "SkyLake.Huang" <skylake.huang@mediatek.com>
> > 
> > v1:
> > Add support for internal 2.5Gphy on MT7988. This driver will load
> > necessary firmware, add appropriate time delay and figure out LED.
> > Also, certain control registers will be set to fix link-up issues.
> > 
> > v2:
> > 1. Move md32_en_cfg_base & pmb_addr detection in probe function.
> > 2. Do not read PMB & MD32_EN_CFG base addresses from dts. We won't
> > change that from board to board. Leave them in driver code. Also,
> > release those addresses after firmware is triggered.
> > 3. Remove half duplex code which leads to ambiguity. Those are for
> > testing & developing previously.
> > 4. Use correct BMCR definitions.
> > 5. Correct config_aneg / get_features / read_status functions.
> > 6. Change mt7988_2p5ge prefix to mt798x_2p5ge in case that our next
> > platform uses this 2.5Gphy driver.
> > 
> > v3:
> > 1. Add range check for firmware.
> > 2. Fix c45_ids.mmds_present in probe function.
> > 3. Still use genphy_update_link() in read_status because
> > genphy_c45_read_link() can't correct detect link on this phy.
> > 
> > v4:
> > 1. Move firmware loading function to mt798x_2p5ge_phy_load_fw()
> > 2. Add AN disable warning in mt798x_2p5ge_phy_config_aneg()
> > 3. Clarify the HDX comments in mt798x_2p5ge_phy_get_features()
> > 
> > v5:
> > 1. Move md32_en_cfg_base & pmb_addr to local variables to achieve
> > symmetric code.
> > 2. Print out firmware date code & version.
> > 3. Don't return error if LED pinctrl switching fails. Also, add
> > comments to this unusual operations.
> > 4. Return -EOPNOTSUPP for AN off case in config_aneg().
> > 
> 
> Hi Sky,
> 
> This is a somewhat unusual way to arrange a patch description.
> 
> Usually the description describes the change, particularly why
> the change is being made.
> 
> While the per-version changes are listed below the scissors ("---").
> 
> > Signed-off-by: SkyLake.Huang <skylake.huang@mediatek.com>
> 
> ...
> 
> > diff --git a/drivers/net/phy/mediatek/mtk-2p5ge.c
> b/drivers/net/phy/mediatek/mtk-2p5ge.c
> 
> ...
> 
> > +static int mt798x_2p5ge_phy_load_fw(struct phy_device *phydev)
> > +{
> > +struct mtk_i2p5ge_phy_priv *priv = phydev->priv;
> > +void __iomem *md32_en_cfg_base, *pmb_addr;
> > +struct device *dev = &phydev->mdio.dev;
> > +const struct firmware *fw;
> > +int ret, i;
> > +u16 reg;
> > +
> > +if (priv->fw_loaded)
> > +return 0;
> > +
> > +pmb_addr = ioremap(MT7988_2P5GE_PMB_BASE, MT7988_2P5GE_PMB_LEN);
> > +if (!pmb_addr)
> > +return -ENOMEM;
> > +md32_en_cfg_base = ioremap(MT7988_2P5GE_MD32_EN_CFG_BASE,
> MT7988_2P5GE_MD32_EN_CFG_LEN);
> 
> nit: Networking still prefers code to be 80 columns wide or less.
>      It looks like that can be trivially achieved here and
>      several other places in this patch.
> 
>      OTOH, I don't think there is no need to break lines to meet this
>      requirement where it is particularly awkward to do so.
> 
>      Flagged by checkpatch.pl --max-line-length=80
> 
> > +if (!md32_en_cfg_base) {
> > +ret = -ENOMEM;
> > +goto free_pmb;
> > +}
> > +
> > +ret = request_firmware(&fw, MT7988_2P5GE_PMB, dev);
> > +if (ret) {
> > +dev_err(dev, "failed to load firmware: %s, ret: %d\n",
> > +MT7988_2P5GE_PMB, ret);
> > +goto free;
> > +}
> > +
> > +if (fw->size != MT7988_2P5GE_PMB_SIZE) {
> > +dev_err(dev, "Firmware size 0x%zx != 0x%x\n",
> > +fw->size, MT7988_2P5GE_PMB_SIZE);
> > +ret = -EINVAL;
> > +goto free;
> > +}
> > +
> > +reg = readw(md32_en_cfg_base);
> > +if (reg & MD32_EN) {
> > +phy_set_bits(phydev, MII_BMCR, BMCR_RESET);
> > +usleep_range(10000, 11000);
> > +}
> > +phy_set_bits(phydev, MII_BMCR, BMCR_PDOWN);
> > +
> > +/* Write magic number to safely stall MCU */
> > +phy_write_mmd(phydev, MDIO_MMD_VEND1, 0x800e, 0x1100);
> > +phy_write_mmd(phydev, MDIO_MMD_VEND1, 0x800f, 0x00df);
> > +
> > +for (i = 0; i < MT7988_2P5GE_PMB_SIZE - 1; i += 4)
> > +writel(*((uint32_t *)(fw->data + i)), pmb_addr + i);
> > +release_firmware(fw);
> > +dev_info(dev, "Firmware date code: %x/%x/%x, version: %x.%x\n",
> > + be16_to_cpu(*((uint16_t *)(fw->data + MT7988_2P5GE_PMB_SIZE -
> 8))),
> 
> If the data at fw->data + MT7988_2P5GE_PMB_SIZE - 8 is a 16-bit
> Big Endian value, then I think the cast should be to __be16 rather
> than uint16_t (and in any case u16 would be preferred to uint16_t
> as this is Kernel code).
> 
> Flagged by Sparse.
> 
> > + *(fw->data + MT7988_2P5GE_PMB_SIZE - 6),
> > + *(fw->data + MT7988_2P5GE_PMB_SIZE - 5),
> > + *(fw->data + MT7988_2P5GE_PMB_SIZE - 2),
> > + *(fw->data + MT7988_2P5GE_PMB_SIZE - 1));
> > +
> > +writew(reg & ~MD32_EN, md32_en_cfg_base);
> > +writew(reg | MD32_EN, md32_en_cfg_base);
> > +phy_set_bits(phydev, MII_BMCR, BMCR_RESET);
> > +/* We need a delay here to stabilize initialization of MCU */
> > +usleep_range(7000, 8000);
> > +dev_info(dev, "Firmware loading/trigger ok.\n");
> > +
> > +priv->fw_loaded = true;
> > +
> > +free:
> > +iounmap(md32_en_cfg_base);
> > +free_pmb:
> > +iounmap(pmb_addr);
> > +
> > +return ret ? ret : 0;
> > +}
> 
> ...
> 
> > +static int mt798x_2p5ge_phy_led_blink_set(struct phy_device
> *phydev, u8 index,
> > +  unsigned long *delay_on,
> > +  unsigned long *delay_off)
> > +{
> > +bool blinking = false;
> > +int err = 0;
> > +struct mtk_i2p5ge_phy_priv *priv = phydev->priv;
> 
> nit: Please consider arranging local variables in reverse xmas tree
> order - 
>      longest line to shortest.
> 
>      Edward Cree's tool can be helpful:
>      https://github.com/ecree-solarflare/xmastree
> 
> > +
> > +if (index > 1)
> > +return -EINVAL;
> > +
> > +if (delay_on && delay_off && (*delay_on > 0) && (*delay_off > 0))
> {
> > +blinking = true;
> > +*delay_on = 50;
> > +*delay_off = 50;
> > +}
> > +
> > +err = mtk_phy_hw_led_blink_set(phydev, index, &priv->led_state,
> blinking);
> > +if (err)
> > +return err;
> > +
> > +return mtk_phy_hw_led_on_set(phydev, index, &priv->led_state,
> > +     MTK_2P5GPHY_LED_ON_MASK, false);
> > +}
> 
> ...
Thanks. I'll fix all of the above in v6.

Sky