[U-Boot] [PATCH] phy: add a NO-OP phy driver

[Marek Vasut]

On 07/21/2017 02:55 PM, Jean-Jacques Hiblot wrote:
> 
> 
> On 21/07/2017 11:03, Marek Vasut wrote:
>> On 07/21/2017 10:49 AM, Jean-Jacques Hiblot wrote:
>>> The no-op phy driver is useful when a driver uses the phy framework
>>> but no PHY driver is available for the hardware (or the hardware has no
>>> PHY).
>>>
>>> Signed-off-by: Jean-Jacques Hiblot <jjhiblot at ti.com>
>>> ---
>>>
>>> Following the email thread '[PATCH 1/1] dm: phy: add missing #ifdef
>>> CONFIG_PHY',
>>> here is a patch to add support for a no-op phy.
>>>
>>> Jean-Jacques
>>>
>>>
>>>   Documentation/devicetree/bindings/phy/no-op.txt | 16 +++++++++++++++
>>>   drivers/phy/Kconfig                             | 18 +++++++++++++++++
>>>   drivers/phy/Makefile                            |  1 +
>>>   drivers/phy/noop-phy.c                          | 26
>>> +++++++++++++++++++++++++
>>>   4 files changed, 61 insertions(+)
>>>   create mode 100644 Documentation/devicetree/bindings/phy/no-op.txt
>>>   create mode 100644 drivers/phy/noop-phy.c
>>>
>>> diff --git a/Documentation/devicetree/bindings/phy/no-op.txt
>>> b/Documentation/devicetree/bindings/phy/no-op.txt
>>> new file mode 100644
>>> index 0000000..eb1a562
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/phy/no-op.txt
>>> @@ -0,0 +1,16 @@
>>> +NO-OP Phy driver
>>> +
>>> +The driver is used to stub PHY opeartions in a driver (USB, SATA).
>> operations
>>
>>> +This is useful when the PHY driver for a particular hardware doesn't
>>> exist yet
>>> +(the hardware is initialized by the platform code).
>>> +
>>> +Required properties:
>>> +- compatible     : must contain "noop-phy"
>>> +- #phy-cells     : must contain <0>
>>> +
>>> +Example:
>>> +
>>> +noop_phy {
>>> +    compatible = "noop-phy";
>>> +    #phy-cells = <0>;
>>> +};
>>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>>> index 7841554..68dced7 100644
>>> --- a/drivers/phy/Kconfig
>>> +++ b/drivers/phy/Kconfig
>>> @@ -41,6 +41,24 @@ config PHY_SANDBOX
>>>         This select a dummy sandbox PHY driver. It used only to
>>> implement
>>>         the unit tests for the phy framework
>>>   +config NOOP_PHY
>>> +    bool "no-op phy"
>> Please fix the option description, this is quite sloppy.
> It's not that I want to induce in sloppiness, but I can't come up with a
> better description.
> Suggestions are welcome.

NOP USB PHY driver or something ?

>>> +    depends on PHY
>>> +    help
>>> +      Support for a no-op PHY
>>> +
>>> +      This is useful when a driver uses the PHY framework but no driver
>>> +      has yet been written for the PHY (or if there is no hardware
>>> PHY).
>> This really is only useful if there is no dedicated PHY.
> Also during the transition from platform code to DM code for the PHY. It
> allows setting up the 'client' driver first, and then the PHY driver.

You should implement a proper driver, we should not advertise this
possibility.

>>> +config SPL_NOOP_PHY
>>> +    bool "no-op phy in SPL"
>> DTTO
>>
>>> +    depends on SPL_PHY
>>> +    help
>>> +      Support for a no-op PHY in SPL
>>> +
>>> +      This is useful when a driver uses the PHY framework but no driver
>>> +      has yet been written for the PHY (or if there is no hardware
>>> PHY).
>>> +
>>>   config PIPE3_PHY
>>>       bool "Support omap's PIPE3 PHY"
>>>       depends on PHY && ARCH_OMAP2PLUS
>>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>>> index 6ce96d2..f129b5c 100644
>>> --- a/drivers/phy/Makefile
>>> +++ b/drivers/phy/Makefile
>>> @@ -6,5 +6,6 @@
>>>   #
>>>     obj-$(CONFIG_$(SPL_)PHY) += phy-uclass.o
>>> +obj-$(CONFIG_$(SPL_)NOOP_PHY) += noop-phy.o
>>>   obj-$(CONFIG_PHY_SANDBOX) += sandbox-phy.o
>>>   obj-$(CONFIG_$(SPL_)PIPE3_PHY) += ti-pipe3-phy.o
>>> diff --git a/drivers/phy/noop-phy.c b/drivers/phy/noop-phy.c
>>> new file mode 100644
>>> index 0000000..14ccf86
>>> --- /dev/null
>>> +++ b/drivers/phy/noop-phy.c
>>> @@ -0,0 +1,26 @@
>>> +/*
>>> + * Copyright (C) 2017 Texas Instruments Incorporated -
>>> http://www.ti.com/
>>> + * Written by Jean-Jacques Hiblot  <jjhiblot at ti.com>
>>> + *
>>> + * SPDX-License-Identifier:    GPL-2.0+
>>> + */
>>> +
>>> +#include <common.h>
>>> +#include <dm.h>
>>> +#include <dm/device.h>
>>> +#include <generic-phy.h>
>>> +
>>> +static const struct udevice_id noop_phy_ids[] = {
>>> +    { .compatible = "noop-phy" },
>>> +    { }
>>> +};
>>> +
>>> +static struct phy_ops noop_phy_ops = {
>>> +};
>>> +
>>> +U_BOOT_DRIVER(noop_phy) = {
>>> +    .name    = "noop_phy",
>>> +    .id    = UCLASS_PHY,
>>> +    .of_match = noop_phy_ids,
>>> +    .ops = &noop_phy_ops,
>>> +};
>>>
>>
> 


-- 
Best regards,
Marek Vasut