Subject: [PATCH v4] PHY: sunxi: Add driver for sunxi usb phy

From: [email-masked] (Kishon Vijay Abraham I)
Date: Wed, 5 Mar 2014 11:09:25 +0530

On Tuesday 04 March 2014 10:33 PM, Hans de Goede wrote:
> Hi,
>
> On 03/03/2014 02:18 PM, Kishon Vijay Abraham I wrote:
>> Hi,
>>
>>
>> On Sunday 02 March 2014 12:49 AM, Hans de Goede wrote:
>>> Hi,
>>>
>>> On 03/01/2014 06:37 PM, Kishon Vijay Abraham I wrote:
>>>> Hi,
>>>>
>>>> On Saturday 01 March 2014 10:39 PM, Hans de Goede wrote:
>>>>> The Allwinner A1x / A2x SoCs have 2 or 3 usb phys which are all
>>>>> accessed
>>>>> through a single set of registers. Besides this there are also some
>>>>> other
>>>>> phy related bits which need poking, which are per phy, but shared
>>>>> between the
>>>>> ohci and ehci controllers, so these are also controlled from this
>>>>> new phy
>>>>> driver.
>>>>>
>>>>> Signed-off-by: Hans de Goede <[email-masked]>
>>>>> Acked-by: Maxime Ripard <[email-masked]>
>>>>> ---
>>>>>    .../devicetree/bindings/phy/sun4i-usb-phy.txt      |  26 ++
>>>>>    drivers/phy/Kconfig                                |  11 +
>>>>>    drivers/phy/Makefile                               |   1 +
>>>>>    drivers/phy/phy-sun4i-usb.c                        | 331
>>>>> +++++++++++++++++++++
>>>>>    4 files changed, 369 insertions(+)
>>>>>    create mode 100644
>>>>> Documentation/devicetree/bindings/phy/sun4i-usb-phy.txt
>>>>>    create mode 100644 drivers/phy/phy-sun4i-usb.c
>>>>>
>>>> ..
>>>> <snip>
>>>> .
>>>> .
>>>>
>>>>> +static int sun4i_usb_phy_init(struct phy *_phy)
>>>>> +{
>>>>> +    struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
>>>>> +    struct sun4i_usb_phy_data *data = to_sun4i_usb_phy_data(phy);
>>>>> +    int ret;
>>>>> +
>>>>> +    ret = clk_prepare_enable(data->clk);
>>>>> +    if (ret)
>>>> dev_err here?
>>>
>>> I would expect the clk subsys to print an error if anything goes
>>> wrong here, repeating that error in the device driver seems
>>> not useful to me.
>>>
>>> Note that this practice of simply propagating the error is a common
>>> pattern in many many users of the clk / reset / regulator framework.
>>>
>>> Also can I please get one final review of this patch rather then
>>> a round of comments ending with:
>>>
>>> "If you can fix these minor comments while changing the $subject
>>> (PHY: sunxi) it
>>> should be good to get merged."
>>>
>>> Only to get more review comments when I've already fixed the minor
>>> comments ?
>>>
>>>>> +        return ret;
>>>>> +
>>>>> +    ret = reset_control_deassert(phy->reset);
>>>>> +    if (ret) {
>>>>
>>>> here too..
>>>
>>> idem.
>>>
>>>>> +        clk_disable_unprepare(data->clk);
>>>>> +        return ret;
>>>>> +    }
>>>>> +
>>>>> +    /* Adjust PHY's magnitude and rate */
>>>>> +    sun4i_usb_phy_write(phy, PHY_TX_AMPLITUDE_TUNE, 0x14, 5);
>>>>> +
>>>>> +    /* Disconnect threshold adjustment */
>>>>> +    sun4i_usb_phy_write(phy, PHY_DISCON_TH_SEL, data->disc_thresh,
>>>>> 2);
>>>>> +
>>>>> +    sun4i_usb_phy_passby(phy, 1);
>>>>> +
>>>>> +    return 0;
>>>>> +}
>>>>> +
>>>>> +static int sun4i_usb_phy_exit(struct phy *_phy)
>>>>> +{
>>>>> +    struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
>>>>> +    struct sun4i_usb_phy_data *data = to_sun4i_usb_phy_data(phy);
>>>>> +
>>>>> +    sun4i_usb_phy_passby(phy, 0);
>>>>> +    reset_control_assert(phy->reset);
>>>>> +    clk_disable_unprepare(data->clk);
>>>>> +
>>>>> +    return 0;
>>>>> +}
>>>>> +
>>>>> +static int sun4i_usb_phy_power_on(struct phy *_phy)
>>>>> +{
>>>>> +    struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
>>>>> +    int ret = 0;
>>>>> +
>>>>> +    if (phy->vbus)
>>>>> +        ret = regulator_enable(phy->vbus);
>>>> dev_err here too..
>>>
>>> idem.
>>>
>>>>> +
>>>>> +    return ret;
>>>>> +}
>>>>> +
>>>>> +static int sun4i_usb_phy_power_off(struct phy *_phy)
>>>>> +{
>>>>> +    struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
>>>>> +
>>>>> +    if (phy->vbus)
>>>>> +        regulator_disable(phy->vbus);
>>>>> +
>>>>> +    return 0;
>>>>> +}
>>>>> +
>>>>> +static struct phy_ops sun4i_usb_phy_ops = {
>>>>> +    .init        = sun4i_usb_phy_init,
>>>>> +    .exit        = sun4i_usb_phy_exit,
>>>>> +    .power_on    = sun4i_usb_phy_power_on,
>>>>> +    .power_off    = sun4i_usb_phy_power_off,
>>>>> +    .owner        = THIS_MODULE,
>>>>> +};
>>>>> +
>>>>> +static struct phy *sun4i_usb_phy_xlate(struct device *dev,
>>>>> +                    struct of_phandle_args *args)
>>>>> +{
>>>>> +    struct sun4i_usb_phy_data *data = dev_get_drvdata(dev);
>>>>> +
>>>>> +    if (WARN_ON(args->args[0] == 0 || args->args[0] >=
>>>>> data->num_phys))
>>>>> +        return ERR_PTR(-ENODEV);
>>>>> +
>>>>> +    return data->phys[args->args[0]].phy;
>>>>> +}
>>>>> +
>>>>> +static int sun4i_usb_phy_probe(struct platform_device *pdev)
>>>>> +{
>>>>> +    struct sun4i_usb_phy_data *data;
>>>>> +    struct device *dev = &pdev->dev;
>>>>> +    struct device_node *np = dev->of_node;
>>>>> +    void __iomem *pmu = NULL;
>>>>> +    struct phy_provider *phy_provider;
>>>>> +    struct reset_control *reset;
>>>>> +    struct regulator *vbus;
>>>>> +    struct resource *res;
>>>>> +    struct phy *phy;
>>>>> +    char name[16];
>>>>> +    int i;
>>>>> +
>>>>> +    data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
>>>>> +    if (!data)
>>>>> +        return -ENOMEM;
>>>>> +
>>>>> +    mutex_init(&data->mutex);
>>>>> +
>>>>> +    if (of_device_is_compatible(np, "allwinner,sun5i-a13-usb-phy"))
>>>>> +        data->num_phys = 2;
>>>>> +    else
>>>>> +        data->num_phys = 3;
>>>>> +
>>>>> +    if (of_device_is_compatible(np, "allwinner,sun4i-a10-usb-phy"))
>>>>> +        data->disc_thresh = 3;
>>>>> +    else
>>>>> +        data->disc_thresh = 2;
>>>>
>>>> These 'data' can actually be part of 'of_device_id' table and can be
>>>> obtained by using 'of_match_device'.
>>>
>>> This was already suggested by Maxime around the time of v2, and
>>> I responded with this:
>>>
>>> "The problem with using the of_device_id .data field is that I can only
>>> store a single integer there. To store 2 I need to: define a struct,
>>> create an array of these structs with initialization. Create an enum for
>>> indexing the array which must be kept in sync with the initializers
>>> manually, store either the index, or a direct pointer to the correct
>>> array
>>> entry into the .data field, add code to get the of_device_id from the
>>> compatible string, and then finally extract the settings from the struct
>>> again.
>>>
>>> See IE how this is done in drivers/ata/ahci_platform.c, I've tried
>>> to come up with a simpler way and failed, for ahci_platform.c the
>>> struct with per compatible-string data is quite big so it makes some
>>> sense to use this construction. Here however not so much, this adds a
>>> whole lot of unnecessary extra code + indirection. I esp. object against
>>> the indirection as that unnecessarily makes it harder to follow whats
>>> going on."
>>
>> alright.. missed that earlier. Sorry.
>
> So does this mean you're going to take v4 as is, or do you want me to add
> the dev_err calls you've pointed out before (note I still prefer to not
> add these, but if you insist...) ?

You should have received a notification on it being merged to 'next'. 
didn't you?

-Kishon