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SubjectRe: [PATCH v2 2/2] phy: socionext: Add UniPhier AHCI PHY driver support
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Hi Vinod,

On 2020/07/13 14:05, Vinod Koul wrote:
> On 30-06-20, 17:59, Kunihiko Hayashi wrote:
>
>> +++ b/drivers/phy/socionext/phy-uniphier-ahci.c
>> @@ -0,0 +1,335 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * phy-uniphier-ahci.c - PHY driver for UniPhier AHCI controller
>> + * Copyright 2016-2018, Socionext Inc.
>
> we are in 2020 now!

Oops, I'll adjust it.

>> +static int uniphier_ahciphy_pxs2_power_on(struct uniphier_ahciphy_priv *priv)
>> +{
>> + int ret;
>> + u32 val;
>> +
>> + /* enable reference clock for PHY */
>> + val = readl(priv->base + CKCTRL);
>> + val |= CKCTRL_REF_SSP_EN;
>> + writel(val, priv->base + CKCTRL);
>> +
>> + /* release port reset */
>> + val = readl(priv->base + CKCTRL);
>> + val &= ~CKCTRL_P0_RESET;
>> + writel(val, priv->base + CKCTRL);
>> +
>> + /* wait until PLL is ready */
>> + if (priv->data->is_ready_high)
>> + ret = readl_poll_timeout(priv->base + CKCTRL, val,
>> + (val & CKCTRL_P0_READY), 200, 400);
>> + else
>> + ret = readl_poll_timeout(priv->base + CKCTRL, val,
>> + !(val & CKCTRL_P0_READY), 200, 400);
>> + if (ret) {
>> + dev_err(priv->dev, "Failed to check whether PHY PLL is ready\n");
>> + goto out_disable_clock;
>> + }
>> +
>> + return 0;
>> +
>> +out_disable_clock:
>> + /* assert port reset */
>> + val = readl(priv->base + CKCTRL);
>> + val |= CKCTRL_P0_RESET;
>> + writel(val, priv->base + CKCTRL);
>> +
>> + /* disable reference clock for PHY */
>> + val = readl(priv->base + CKCTRL);
>> + val &= ~CKCTRL_REF_SSP_EN;
>> + writel(val, priv->base + CKCTRL);
>
> this seems to be repeated patter, why not add a modifyl() helper here..

Hmm, I try to add helpers for modifying P0_RESET and REF_SSP_EN bits.

>
>> +static int uniphier_ahciphy_pxs3_init(struct uniphier_ahciphy_priv *priv)
>> +{
>> + int i;
>> + u32 val;
>> +
>> + /* setup port parameter */
>> + val = readl(priv->base + TXCTRL0);
>> + val &= ~TXCTRL0_AMP_G3_MASK;
>> + val |= FIELD_PREP(TXCTRL0_AMP_G3_MASK, 0x73);
>> + val &= ~TXCTRL0_AMP_G2_MASK;
>> + val |= FIELD_PREP(TXCTRL0_AMP_G2_MASK, 0x46);
>> + val &= ~TXCTRL0_AMP_G1_MASK;
>> + val |= FIELD_PREP(TXCTRL0_AMP_G1_MASK, 0x42);
>> + writel(val, priv->base + TXCTRL0);
>> +
>> + val = readl(priv->base + TXCTRL1);
>> + val &= ~TXCTRL1_DEEMPH_G3_MASK;
>> + val |= FIELD_PREP(TXCTRL1_DEEMPH_G3_MASK, 0x23);
>> + val &= ~TXCTRL1_DEEMPH_G2_MASK;
>> + val |= FIELD_PREP(TXCTRL1_DEEMPH_G2_MASK, 0x05);
>> + val &= ~TXCTRL1_DEEMPH_G1_MASK;
>> + val |= FIELD_PREP(TXCTRL1_DEEMPH_G1_MASK, 0x05);
>> +
>> + val = readl(priv->base + RXCTRL);
>> + val &= ~RXCTRL_LOS_LVL_MASK;
>> + val |= FIELD_PREP(RXCTRL_LOS_LVL_MASK, 0x9);
>> + val &= ~RXCTRL_LOS_BIAS_MASK;
>> + val |= FIELD_PREP(RXCTRL_LOS_BIAS_MASK, 0x2);
>> + val &= ~RXCTRL_RX_EQ_MASK;
>> + val |= FIELD_PREP(RXCTRL_RX_EQ_MASK, 0x1);
>> +
>> + /* dummy read 25 times */
>
> why?

According to the specification document,
these 25 read accesses make a wait time for the phy to stablize.
I'll add the reason as comment.

>
>> +static int uniphier_ahciphy_init(struct phy *phy)
>> +{
>> + struct uniphier_ahciphy_priv *priv = phy_get_drvdata(phy);
>> + int ret;
>> +
>> + ret = clk_prepare_enable(priv->clk_parent);
>> + if (ret)
>> + return ret;
>> +
>> + ret = reset_control_deassert(priv->rst_parent);
>> + if (ret)
>> + goto out_clk_disable;
>> +
>> + if (priv->data->init) {
>> + ret = priv->data->init(priv);
>> + if (ret)
>> + goto out_rst_assert;
>> + }
>> +
>> + return ret;
>
> return 0?

Yes, I'll fix it.

>
>> +static const struct uniphier_ahciphy_soc_data uniphier_pxs2_data = {
>> + .init = NULL,
>
> Isn't this superfluous ?

Indeed, this can be removed.

Thank you,

---
Best Regards
Kunihiko Hayashi

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