Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH v2 5/8] phy: amlogic: add Amlogic G12A USB2 PHY Driver
To:     Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc:     gregkh@linuxfoundation.org, hminas@synopsys.com, balbi@kernel.org,
        kishon@ti.com, linux-amlogic@lists.infradead.org,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org
References: <20190304103846.2060-1-narmstrong@baylibre.com>
 <20190304103846.2060-6-narmstrong@baylibre.com>
 <CAFBinCAacdsjwtg_RK=e=Lnep7oLF+eTBmkb1FB4nFR129z1jA@mail.gmail.com>
From:   Neil Armstrong <narmstrong@baylibre.com>
Openpgp: preference=signencrypt
Autocrypt: addr=narmstrong@baylibre.com; prefer-encrypt=mutual; keydata=
 mQENBE1ZBs8BCAD78xVLsXPwV/2qQx2FaO/7mhWL0Qodw8UcQJnkrWmgTFRobtTWxuRx8WWP
 GTjuhvbleoQ5Cxjr+v+1ARGCH46MxFP5DwauzPekwJUD5QKZlaw/bURTLmS2id5wWi3lqVH4
 BVF2WzvGyyeV1o4RTCYDnZ9VLLylJ9bneEaIs/7cjCEbipGGFlfIML3sfqnIvMAxIMZrvcl9
 qPV2k+KQ7q+aXavU5W+yLNn7QtXUB530Zlk/d2ETgzQ5FLYYnUDAaRl+8JUTjc0CNOTpCeik
 80TZcE6f8M76Xa6yU8VcNko94Ck7iB4vj70q76P/J7kt98hklrr85/3NU3oti3nrIHmHABEB
 AAG0KE5laWwgQXJtc3Ryb25nIDxuYXJtc3Ryb25nQGJheWxpYnJlLmNvbT6JATsEEwEKACUC
 GyMGCwkIBwMCBhUIAgkKCwQWAgMBAh4BAheABQJXDO2CAhkBAAoJEBaat7Gkz/iubGIH/iyk
 RqvgB62oKOFlgOTYCMkYpm2aAOZZLf6VKHKc7DoVwuUkjHfIRXdslbrxi4pk5VKU6ZP9AKsN
 NtMZntB8WrBTtkAZfZbTF7850uwd3eU5cN/7N1Q6g0JQihE7w4GlIkEpQ8vwSg5W7hkx3yQ6
 2YzrUZh/b7QThXbNZ7xOeSEms014QXazx8+txR7jrGF3dYxBsCkotO/8DNtZ1R+aUvRfpKg5
 ZgABTC0LmAQnuUUf2PHcKFAHZo5KrdO+tyfL+LgTUXIXkK+tenkLsAJ0cagz1EZ5gntuheLD
 YJuzS4zN+1Asmb9kVKxhjSQOcIh6g2tw7vaYJgL/OzJtZi6JlIW5AQ0ETVkGzwEIALyKDN/O
 GURaHBVzwjgYq+ZtifvekdrSNl8TIDH8g1xicBYpQTbPn6bbSZbdvfeQPNCcD4/EhXZuhQXM
 coJsQQQnO4vwVULmPGgtGf8PVc7dxKOeta+qUh6+SRh3vIcAUFHDT3f/Zdspz+e2E0hPV2hi
 SvICLk11qO6cyJE13zeNFoeY3ggrKY+IzbFomIZY4yG6xI99NIPEVE9lNBXBKIlewIyVlkOa
 YvJWSV+p5gdJXOvScNN1epm5YHmf9aE2ZjnqZGoMMtsyw18YoX9BqMFInxqYQQ3j/HpVgTSv
 mo5ea5qQDDUaCsaTf8UeDcwYOtgI8iL4oHcsGtUXoUk33HEAEQEAAYkBHwQYAQIACQUCTVkG
 zwIbDAAKCRAWmrexpM/4rrXiB/sGbkQ6itMrAIfnM7IbRuiSZS1unlySUVYu3SD6YBYnNi3G
 5EpbwfBNuT3H8//rVvtOFK4OD8cRYkxXRQmTvqa33eDIHu/zr1HMKErm+2SD6PO9umRef8V8
 2o2oaCLvf4WeIssFjwB0b6a12opuRP7yo3E3gTCSKmbUuLv1CtxKQF+fUV1cVaTPMyT25Od+
 RC1K+iOR0F54oUJvJeq7fUzbn/KdlhA8XPGzwGRy4zcsPWvwnXgfe5tk680fEKZVwOZKIEuJ
 C3v+/yZpQzDvGYJvbyix0lHnrCzq43WefRHI5XTTQbM0WUIBIcGmq38+OgUsMYu4NzLu7uZF
 Acmp6h8guQINBFYnf6QBEADQ+wBYa+X2n/xIQz/RUoGHf84Jm+yTqRT43t7sO48/cBW9vAn9
 GNwnJ3HRJWKATW0ZXrCr40ES/JqM1fUTfiFDB3VMdWpEfwOAT1zXS+0rX8yljgsWR1UvqyEP
 3xN0M/40Zk+rdmZKaZS8VQaXbveaiWMEmY7sBV3QvgOzB7UF2It1HwoCon5Y+PvyE3CguhBd
 9iq5iEampkMIkbA3FFCpQFI5Ai3BywkLzbA3ZtnMXR8Qt9gFZtyXvFQrB+/6hDzEPnBGZOOx
 zkd/iIX59SxBuS38LMlhPPycbFNmtauOC0DNpXCv9ACgC9tFw3exER/xQgSpDVc4vrL2Cacr
 wmQp1k9E0W+9pk/l8S1jcHx03hgCxPtQLOIyEu9iIJb27TjcXNjiInd7Uea195NldIrndD+x
 58/yU3X70qVY+eWbqzpdlwF1KRm6uV0ZOQhEhbi0FfKKgsYFgBIBchGqSOBsCbL35f9hK/JC
 6LnGDtSHeJs+jd9/qJj4WqF3x8i0sncQ/gszSajdhnWrxraG3b7/9ldMLpKo/OoihfLaCxtv
 xYmtw8TGhlMaiOxjDrohmY1z7f3rf6njskoIXUO0nabun1nPAiV1dpjleg60s3OmVQeEpr3a
 K7gR1ljkemJzM9NUoRROPaT7nMlNYQL+IwuthJd6XQqwzp1jRTGG26J97wARAQABiQM+BBgB
 AgAJBQJWJ3+kAhsCAikJEBaat7Gkz/iuwV0gBBkBAgAGBQJWJ3+kAAoJEHfc29rIyEnRk6MQ
 AJDo0nxsadLpYB26FALZsWlN74rnFXth5dQVQ7SkipmyFWZhFL8fQ9OiIoxWhM6rSg9+C1w+
 n45eByMg2b8H3mmQmyWztdI95OxSREKwbaXVapCcZnv52JRjlc3DoiiHqTZML5x1Z7lQ1T3F
 8o9sKrbFO1WQw1+Nc91+MU0MGN0jtfZ0Tvn/ouEZrSXCE4K3oDGtj3AdC764yZVq6CPigCgs
 6Ex80k6QlzCdVP3RKsnPO2xQXXPgyJPJlpD8bHHHW7OLfoR9DaBNympfcbQJeekQrTvyoASw
 EOTPKE6CVWrcQIztUp0WFTdRGgMK0cZB3Xfe6sOp24PQTHAKGtjTHNP/THomkH24Fum9K3iM
 /4Wh4V2eqGEgpdeSp5K+LdaNyNgaqzMOtt4HYk86LYLSHfFXywdlbGrY9+TqiJ+ZVW4trmui
 NIJCOku8SYansq34QzYM0x3UFRwff+45zNBEVzctSnremg1mVgrzOfXU8rt+4N1b2MxorPF8
 619aCwVP7U16qNSBaqiAJr4e5SNEnoAq18+1Gp8QsFG0ARY8xp+qaKBByWES7lRi3QbqAKZf
 yOHS6gmYo9gBmuAhc65/VtHMJtxwjpUeN4Bcs9HUpDMDVHdfeRa73wM+wY5potfQ5zkSp0Jp
 bxnv/cRBH6+c43stTffprd//4Hgz+nJcCgZKtCYIAPkUxABC85ID2CidzbraErVACmRoizhT
 KR2OiqSLW2x4xdmSiFNcIWkWJB6Qdri0Fzs2dHe8etD1HYaht1ZhZ810s7QOL7JwypO8dscN
 KTEkyoTGn6cWj0CX+PeP4xp8AR8ot4d0BhtUY34UPzjE1/xyrQFAdnLd0PP4wXxdIUuRs0+n
 WLY9Aou/vC1LAdlaGsoTVzJ2gX4fkKQIWhX0WVk41BSFeDKQ3RQ2pnuzwedLO94Bf6X0G48O
 VsbXrP9BZ6snXyHfebPnno/te5XRqZTL9aJOytB/1iUna+1MAwBxGFPvqeEUUyT+gx1l3Acl
 ZaTUOEkgIor5losDrePdPgE=
Organization: Baylibre
Message-ID: <bd9d1b4b-4dd7-864e-b197-c5993d3dd24f@baylibre.com>
Date:   Thu, 7 Mar 2019 09:41:12 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.4.0
MIME-Version: 1.0
In-Reply-To: <CAFBinCAacdsjwtg_RK=e=Lnep7oLF+eTBmkb1FB4nFR129z1jA@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 06/03/2019 22:00, Martin Blumenstingl wrote:
> Hi Neil,
> 
> On Mon, Mar 4, 2019 at 11:40 AM Neil Armstrong <narmstrong@baylibre.com> wrote:
> [...]
>> +#include <linux/clk.h>
>> +#include <linux/delay.h>
>> +#include <linux/io.h>
>> +#include <linux/module.h>
>> +#include <linux/of_device.h>
>> +#include <linux/regmap.h>
>> +#include <linux/mfd/syscon.h>
> there's a "regmap" include right above. this driver doesn't use syscon
> so this include can be dropped

Forgot this one...

> 
> [...]
>> +static int phy_meson_g12a_usb2_exit(struct phy *phy)
>> +{
>> +       struct phy_meson_g12a_usb2_priv *priv = phy_get_drvdata(phy);
>> +
>> +       return reset_control_reset(priv->reset);
> do you know whether we should reset_control_assert here instead of
> reset_control_reset?
> the probe function below already uses reset_control_deassert, so the
> current implementation is inconsistent. in v1 you replied with "Maybe
> it would be better, indeed." - if there's a reason why
> reset_control_assert doesn't work here then I would like to have a
> comment stating why

It's not clear yet, I implemented it safe here since in my tests, when
I left the USB2 PHYs resetted, it was kept resetted on a soft system reset
and the ROM was not able to setup the PHY correctly.

So maybe it's wrong for power management, it's safer to simply to keep the
PHYs unresetted when unused.

> 
> Apart from these two this is looking good!
> Human readable BIT/GENMASK #defines for the register bits would be
> nice, but I'm not sure if you have the details to add these.

I have the registers set in the doc, but it's much longer than copying
the registers structs from the vendor kernel, so I postponed it.

I'll try adding these, but for now it's low priority unless the PHY maintainer
asks for them.

Neil

> 
> 
> Regards
> Martin
>