diff mbox

[v2,04/13] rc: sunxi-cir: Add support for an optional reset controller

Message ID 1418836704-15689-5-git-send-email-hdegoede@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Hans de Goede Dec. 17, 2014, 5:18 p.m. UTC
On sun6i the cir block is attached to the reset controller, add support
for de-asserting the reset if a reset controller is specified in dt.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 .../devicetree/bindings/media/sunxi-ir.txt         |  2 ++
 drivers/media/rc/sunxi-cir.c                       | 25 ++++++++++++++++++++--
 2 files changed, 25 insertions(+), 2 deletions(-)

Comments

Chen-Yu Tsai Dec. 18, 2014, 2:48 a.m. UTC | #1
Hi,

On Thu, Dec 18, 2014 at 1:18 AM, Hans de Goede <hdegoede@redhat.com> wrote:
> On sun6i the cir block is attached to the reset controller, add support
> for de-asserting the reset if a reset controller is specified in dt.
>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  .../devicetree/bindings/media/sunxi-ir.txt         |  2 ++
>  drivers/media/rc/sunxi-cir.c                       | 25 ++++++++++++++++++++--
>  2 files changed, 25 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/media/sunxi-ir.txt b/Documentation/devicetree/bindings/media/sunxi-ir.txt
> index 23dd5ad..6b70b9b 100644
> --- a/Documentation/devicetree/bindings/media/sunxi-ir.txt
> +++ b/Documentation/devicetree/bindings/media/sunxi-ir.txt
> @@ -10,6 +10,7 @@ Required properties:
>
>  Optional properties:
>  - linux,rc-map-name : Remote control map name.
> +- resets : phandle + reset specifier pair

Should it be optional? Or should we use a sun6i compatible with
a mandatory reset phandle? I mean, the driver/hardware is not
going to work with the reset missing on sun6i.

Seems we are doing it one way for some of our drivers, and
the other (optional) way for more generic ones, like USB.

ChenYu

>  Example:
>
> @@ -17,6 +18,7 @@ ir0: ir@01c21800 {
>         compatible = "allwinner,sun4i-a10-ir";
>         clocks = <&apb0_gates 6>, <&ir0_clk>;
>         clock-names = "apb", "ir";
> +       resets = <&apb0_rst 1>;
>         interrupts = <0 5 1>;
>         reg = <0x01C21800 0x40>;
>         linux,rc-map-name = "rc-rc6-mce";
> diff --git a/drivers/media/rc/sunxi-cir.c b/drivers/media/rc/sunxi-cir.c
> index 340f7f5..06170e0 100644
> --- a/drivers/media/rc/sunxi-cir.c
> +++ b/drivers/media/rc/sunxi-cir.c
> @@ -23,6 +23,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/module.h>
>  #include <linux/of_platform.h>
> +#include <linux/reset.h>
>  #include <media/rc-core.h>
>
>  #define SUNXI_IR_DEV "sunxi-ir"
> @@ -95,6 +96,7 @@ struct sunxi_ir {
>         int             irq;
>         struct clk      *clk;
>         struct clk      *apb_clk;
> +       struct reset_control *rst;
>         const char      *map_name;
>  };
>
> @@ -166,15 +168,29 @@ static int sunxi_ir_probe(struct platform_device *pdev)
>                 return PTR_ERR(ir->clk);
>         }
>
> +       /* Reset (optional) */
> +       ir->rst = devm_reset_control_get_optional(dev, NULL);
> +       if (IS_ERR(ir->rst)) {
> +               ret = PTR_ERR(ir->rst);
> +               if (ret == -EPROBE_DEFER)
> +                       return ret;
> +               ir->rst = NULL;
> +       } else {
> +               ret = reset_control_deassert(ir->rst);
> +               if (ret)
> +                       return ret;
> +       }
> +
>         ret = clk_set_rate(ir->clk, SUNXI_IR_BASE_CLK);
>         if (ret) {
>                 dev_err(dev, "set ir base clock failed!\n");
> -               return ret;
> +               goto exit_reset_assert;
>         }
>
>         if (clk_prepare_enable(ir->apb_clk)) {
>                 dev_err(dev, "try to enable apb_ir_clk failed\n");
> -               return -EINVAL;
> +               ret = -EINVAL;
> +               goto exit_reset_assert;
>         }
>
>         if (clk_prepare_enable(ir->clk)) {
> @@ -271,6 +287,9 @@ exit_clkdisable_clk:
>         clk_disable_unprepare(ir->clk);
>  exit_clkdisable_apb_clk:
>         clk_disable_unprepare(ir->apb_clk);
> +exit_reset_assert:
> +       if (ir->rst)
> +               reset_control_assert(ir->rst);
>
>         return ret;
>  }
> @@ -282,6 +301,8 @@ static int sunxi_ir_remove(struct platform_device *pdev)
>
>         clk_disable_unprepare(ir->clk);
>         clk_disable_unprepare(ir->apb_clk);
> +       if (ir->rst)
> +               reset_control_assert(ir->rst);
>
>         spin_lock_irqsave(&ir->ir_lock, flags);
>         /* disable IR IRQ */
> --
> 2.1.0
>
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Hans de Goede Dec. 18, 2014, 8:50 a.m. UTC | #2
Hi,

On 18-12-14 03:48, Chen-Yu Tsai wrote:
> Hi,
>
> On Thu, Dec 18, 2014 at 1:18 AM, Hans de Goede <hdegoede@redhat.com> wrote:
>> On sun6i the cir block is attached to the reset controller, add support
>> for de-asserting the reset if a reset controller is specified in dt.
>>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
>> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
>> ---
>>   .../devicetree/bindings/media/sunxi-ir.txt         |  2 ++
>>   drivers/media/rc/sunxi-cir.c                       | 25 ++++++++++++++++++++--
>>   2 files changed, 25 insertions(+), 2 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/media/sunxi-ir.txt b/Documentation/devicetree/bindings/media/sunxi-ir.txt
>> index 23dd5ad..6b70b9b 100644
>> --- a/Documentation/devicetree/bindings/media/sunxi-ir.txt
>> +++ b/Documentation/devicetree/bindings/media/sunxi-ir.txt
>> @@ -10,6 +10,7 @@ Required properties:
>>
>>   Optional properties:
>>   - linux,rc-map-name : Remote control map name.
>> +- resets : phandle + reset specifier pair
>
> Should it be optional? Or should we use a sun6i compatible with
> a mandatory reset phandle? I mean, the driver/hardware is not
> going to work with the reset missing on sun6i.
>
> Seems we are doing it one way for some of our drivers, and
> the other (optional) way for more generic ones, like USB.

I do not believe that we should add a new compatible just because
the reset line of a block is hooked up differently. It is the
exact same ip-block. Only now the reset is not controlled
through the apb-gate, but controlled separately.

Regards,

Hans
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Maxime Ripard Dec. 19, 2014, 6:17 p.m. UTC | #3
Hi,

On Thu, Dec 18, 2014 at 09:50:26AM +0100, Hans de Goede wrote:
> Hi,
> 
> On 18-12-14 03:48, Chen-Yu Tsai wrote:
> >Hi,
> >
> >On Thu, Dec 18, 2014 at 1:18 AM, Hans de Goede <hdegoede@redhat.com> wrote:
> >>On sun6i the cir block is attached to the reset controller, add support
> >>for de-asserting the reset if a reset controller is specified in dt.
> >>
> >>Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> >>Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
> >>Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> >>---
> >>  .../devicetree/bindings/media/sunxi-ir.txt         |  2 ++
> >>  drivers/media/rc/sunxi-cir.c                       | 25 ++++++++++++++++++++--
> >>  2 files changed, 25 insertions(+), 2 deletions(-)
> >>
> >>diff --git a/Documentation/devicetree/bindings/media/sunxi-ir.txt b/Documentation/devicetree/bindings/media/sunxi-ir.txt
> >>index 23dd5ad..6b70b9b 100644
> >>--- a/Documentation/devicetree/bindings/media/sunxi-ir.txt
> >>+++ b/Documentation/devicetree/bindings/media/sunxi-ir.txt
> >>@@ -10,6 +10,7 @@ Required properties:
> >>
> >>  Optional properties:
> >>  - linux,rc-map-name : Remote control map name.
> >>+- resets : phandle + reset specifier pair
> >
> >Should it be optional? Or should we use a sun6i compatible with
> >a mandatory reset phandle? I mean, the driver/hardware is not
> >going to work with the reset missing on sun6i.
> >
> >Seems we are doing it one way for some of our drivers, and
> >the other (optional) way for more generic ones, like USB.
> 
> I do not believe that we should add a new compatible just because
> the reset line of a block is hooked up differently. It is the
> exact same ip-block. Only now the reset is not controlled
> through the apb-gate, but controlled separately.

He has a point though. Your driver might very well probe nicely and
everything, but still wouldn't be functional at all because the reset
line wouldn't have been specified in the DT.

The easiest way to deal with that would be in the bindings doc to
update it with a compatible for the A31, and mentionning that the
reset property is mandatory there.

Note that the code itself might not change at all though. I'd just
like to avoid any potential breaking of the DT bindings themselves. If
we further want to refine the code, we can do that however we want.

I have a slight preference for a clean error if reset is missing, but
I won't get in the way just for that.

Maxime
Hans de Goede Dec. 20, 2014, 10:20 a.m. UTC | #4
Hi,

On 19-12-14 19:17, Maxime Ripard wrote:
> Hi,
>
> On Thu, Dec 18, 2014 at 09:50:26AM +0100, Hans de Goede wrote:
>> Hi,
>>
>> On 18-12-14 03:48, Chen-Yu Tsai wrote:
>>> Hi,
>>>
>>> On Thu, Dec 18, 2014 at 1:18 AM, Hans de Goede <hdegoede@redhat.com> wrote:
>>>> On sun6i the cir block is attached to the reset controller, add support
>>>> for de-asserting the reset if a reset controller is specified in dt.
>>>>
>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>> Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
>>>> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
>>>> ---
>>>>   .../devicetree/bindings/media/sunxi-ir.txt         |  2 ++
>>>>   drivers/media/rc/sunxi-cir.c                       | 25 ++++++++++++++++++++--
>>>>   2 files changed, 25 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/media/sunxi-ir.txt b/Documentation/devicetree/bindings/media/sunxi-ir.txt
>>>> index 23dd5ad..6b70b9b 100644
>>>> --- a/Documentation/devicetree/bindings/media/sunxi-ir.txt
>>>> +++ b/Documentation/devicetree/bindings/media/sunxi-ir.txt
>>>> @@ -10,6 +10,7 @@ Required properties:
>>>>
>>>>   Optional properties:
>>>>   - linux,rc-map-name : Remote control map name.
>>>> +- resets : phandle + reset specifier pair
>>>
>>> Should it be optional? Or should we use a sun6i compatible with
>>> a mandatory reset phandle? I mean, the driver/hardware is not
>>> going to work with the reset missing on sun6i.
>>>
>>> Seems we are doing it one way for some of our drivers, and
>>> the other (optional) way for more generic ones, like USB.
>>
>> I do not believe that we should add a new compatible just because
>> the reset line of a block is hooked up differently. It is the
>> exact same ip-block. Only now the reset is not controlled
>> through the apb-gate, but controlled separately.
>
> He has a point though. Your driver might very well probe nicely and
> everything, but still wouldn't be functional at all because the reset
> line wouldn't have been specified in the DT.

Right, just like other drivers we've, see e.g.:

Documentation/devicetree/bindings/mmc/sunxi-mmc.txt

Which is dealing with this in the same way.

> The easiest way to deal with that would be in the bindings doc to
> update it with a compatible for the A31, and mentionning that the
> reset property is mandatory there.

No the easiest way to deal with this is to expect people writing
the dts to know what they are doing, just like we do for a lot
of the other blocks in sun6i.

Maybe put a generic note somewhere that sun6i has a reset controller,
and that for all the blocks with optional resets property it should
be considered mandatory on sun6i ?

I'm sorry but I'm not going to make this change for the ir bindings
given that we've the same situation in a lot of other places.

Consistency is important. Moreover I believe that having a sun6i
specific compatible string is just wrong, since it is the exact
same hardware block as on sun5i, just with its reset line routed
differently, just like e.g. the mmc controller, the uarts or the gmac
all of which also do not have a sun6i specific compatible to enforce
reset controller usage.

Regards,

Hans



> Note that the code itself might not change at all though. I'd just
> like to avoid any potential breaking of the DT bindings themselves. If
> we further want to refine the code, we can do that however we want.
>
> I have a slight preference for a clean error if reset is missing, but
> I won't get in the way just for that.
>
> Maxime
>
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Chen-Yu Tsai Jan. 19, 2015, 2:10 p.m. UTC | #5
Hi,

On Sat, Dec 20, 2014 at 6:20 PM, Hans de Goede <hdegoede@redhat.com> wrote:
> Hi,
>
>
> On 19-12-14 19:17, Maxime Ripard wrote:
>>
>> Hi,
>>
>> On Thu, Dec 18, 2014 at 09:50:26AM +0100, Hans de Goede wrote:
>>>
>>> Hi,
>>>
>>> On 18-12-14 03:48, Chen-Yu Tsai wrote:
>>>>
>>>> Hi,
>>>>
>>>> On Thu, Dec 18, 2014 at 1:18 AM, Hans de Goede <hdegoede@redhat.com>
>>>> wrote:
>>>>>
>>>>> On sun6i the cir block is attached to the reset controller, add support
>>>>> for de-asserting the reset if a reset controller is specified in dt.
>>>>>
>>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>>> Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
>>>>> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
>>>>> ---
>>>>>   .../devicetree/bindings/media/sunxi-ir.txt         |  2 ++
>>>>>   drivers/media/rc/sunxi-cir.c                       | 25
>>>>> ++++++++++++++++++++--
>>>>>   2 files changed, 25 insertions(+), 2 deletions(-)
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/media/sunxi-ir.txt
>>>>> b/Documentation/devicetree/bindings/media/sunxi-ir.txt
>>>>> index 23dd5ad..6b70b9b 100644
>>>>> --- a/Documentation/devicetree/bindings/media/sunxi-ir.txt
>>>>> +++ b/Documentation/devicetree/bindings/media/sunxi-ir.txt
>>>>> @@ -10,6 +10,7 @@ Required properties:
>>>>>
>>>>>   Optional properties:
>>>>>   - linux,rc-map-name : Remote control map name.
>>>>> +- resets : phandle + reset specifier pair
>>>>
>>>>
>>>> Should it be optional? Or should we use a sun6i compatible with
>>>> a mandatory reset phandle? I mean, the driver/hardware is not
>>>> going to work with the reset missing on sun6i.
>>>>
>>>> Seems we are doing it one way for some of our drivers, and
>>>> the other (optional) way for more generic ones, like USB.
>>>
>>>
>>> I do not believe that we should add a new compatible just because
>>> the reset line of a block is hooked up differently. It is the
>>> exact same ip-block. Only now the reset is not controlled
>>> through the apb-gate, but controlled separately.
>>
>>
>> He has a point though. Your driver might very well probe nicely and
>> everything, but still wouldn't be functional at all because the reset
>> line wouldn't have been specified in the DT.
>
>
> Right, just like other drivers we've, see e.g.:
>
> Documentation/devicetree/bindings/mmc/sunxi-mmc.txt
>
> Which is dealing with this in the same way.
>
>> The easiest way to deal with that would be in the bindings doc to
>> update it with a compatible for the A31, and mentionning that the
>> reset property is mandatory there.
>
>
> No the easiest way to deal with this is to expect people writing
> the dts to know what they are doing, just like we do for a lot
> of the other blocks in sun6i.
>
> Maybe put a generic note somewhere that sun6i has a reset controller,
> and that for all the blocks with optional resets property it should
> be considered mandatory on sun6i ?
>
> I'm sorry but I'm not going to make this change for the ir bindings
> given that we've the same situation in a lot of other places.
>
> Consistency is important. Moreover I believe that having a sun6i
> specific compatible string is just wrong, since it is the exact
> same hardware block as on sun5i, just with its reset line routed
> differently, just like e.g. the mmc controller, the uarts or the gmac
> all of which also do not have a sun6i specific compatible to enforce
> reset controller usage.
>
> Regards,
>
> Hans
>
>
>
>
>> Note that the code itself might not change at all though. I'd just
>> like to avoid any potential breaking of the DT bindings themselves. If
>> we further want to refine the code, we can do that however we want.
>>
>> I have a slight preference for a clean error if reset is missing, but
>> I won't get in the way just for that.

Seems this patch and the following patch were overlooked after the
discussion. Any chance we could get this in? Hans has made a good
argument, so I take back any doubts I raised.

ChenYu
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Hans de Goede Jan. 19, 2015, 2:17 p.m. UTC | #6
Hi,

On 19-01-15 15:10, Chen-Yu Tsai wrote:
> Hi,
>
> On Sat, Dec 20, 2014 at 6:20 PM, Hans de Goede <hdegoede@redhat.com> wrote:
>> Hi,
>>
>>
>> On 19-12-14 19:17, Maxime Ripard wrote:
>>>
>>> Hi,
>>>
>>> On Thu, Dec 18, 2014 at 09:50:26AM +0100, Hans de Goede wrote:
>>>>
>>>> Hi,
>>>>
>>>> On 18-12-14 03:48, Chen-Yu Tsai wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> On Thu, Dec 18, 2014 at 1:18 AM, Hans de Goede <hdegoede@redhat.com>
>>>>> wrote:
>>>>>>
>>>>>> On sun6i the cir block is attached to the reset controller, add support
>>>>>> for de-asserting the reset if a reset controller is specified in dt.
>>>>>>
>>>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>>>> Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
>>>>>> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
>>>>>> ---
>>>>>>    .../devicetree/bindings/media/sunxi-ir.txt         |  2 ++
>>>>>>    drivers/media/rc/sunxi-cir.c                       | 25
>>>>>> ++++++++++++++++++++--
>>>>>>    2 files changed, 25 insertions(+), 2 deletions(-)
>>>>>>
>>>>>> diff --git a/Documentation/devicetree/bindings/media/sunxi-ir.txt
>>>>>> b/Documentation/devicetree/bindings/media/sunxi-ir.txt
>>>>>> index 23dd5ad..6b70b9b 100644
>>>>>> --- a/Documentation/devicetree/bindings/media/sunxi-ir.txt
>>>>>> +++ b/Documentation/devicetree/bindings/media/sunxi-ir.txt
>>>>>> @@ -10,6 +10,7 @@ Required properties:
>>>>>>
>>>>>>    Optional properties:
>>>>>>    - linux,rc-map-name : Remote control map name.
>>>>>> +- resets : phandle + reset specifier pair
>>>>>
>>>>>
>>>>> Should it be optional? Or should we use a sun6i compatible with
>>>>> a mandatory reset phandle? I mean, the driver/hardware is not
>>>>> going to work with the reset missing on sun6i.
>>>>>
>>>>> Seems we are doing it one way for some of our drivers, and
>>>>> the other (optional) way for more generic ones, like USB.
>>>>
>>>>
>>>> I do not believe that we should add a new compatible just because
>>>> the reset line of a block is hooked up differently. It is the
>>>> exact same ip-block. Only now the reset is not controlled
>>>> through the apb-gate, but controlled separately.
>>>
>>>
>>> He has a point though. Your driver might very well probe nicely and
>>> everything, but still wouldn't be functional at all because the reset
>>> line wouldn't have been specified in the DT.
>>
>>
>> Right, just like other drivers we've, see e.g.:
>>
>> Documentation/devicetree/bindings/mmc/sunxi-mmc.txt
>>
>> Which is dealing with this in the same way.
>>
>>> The easiest way to deal with that would be in the bindings doc to
>>> update it with a compatible for the A31, and mentionning that the
>>> reset property is mandatory there.
>>
>>
>> No the easiest way to deal with this is to expect people writing
>> the dts to know what they are doing, just like we do for a lot
>> of the other blocks in sun6i.
>>
>> Maybe put a generic note somewhere that sun6i has a reset controller,
>> and that for all the blocks with optional resets property it should
>> be considered mandatory on sun6i ?
>>
>> I'm sorry but I'm not going to make this change for the ir bindings
>> given that we've the same situation in a lot of other places.
>>
>> Consistency is important. Moreover I believe that having a sun6i
>> specific compatible string is just wrong, since it is the exact
>> same hardware block as on sun5i, just with its reset line routed
>> differently, just like e.g. the mmc controller, the uarts or the gmac
>> all of which also do not have a sun6i specific compatible to enforce
>> reset controller usage.
>>
>> Regards,
>>
>> Hans
>>
>>
>>
>>
>>> Note that the code itself might not change at all though. I'd just
>>> like to avoid any potential breaking of the DT bindings themselves. If
>>> we further want to refine the code, we can do that however we want.
>>>
>>> I have a slight preference for a clean error if reset is missing, but
>>> I won't get in the way just for that.
>
> Seems this patch and the following patch were overlooked after the
> discussion. Any chance we could get this in?

I'm a linux/media sub-maintainer, so I've already send a pull-req for
these 2 to the linux/media maintainer, iow this is taken care of :)

Regards,

Hans


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Chen-Yu Tsai Jan. 19, 2015, 2:24 p.m. UTC | #7
On Mon, Jan 19, 2015 at 10:17 PM, Hans de Goede <hdegoede@redhat.com> wrote:
> Hi,
>
>
> On 19-01-15 15:10, Chen-Yu Tsai wrote:
>>
>> Hi,
>>
>> On Sat, Dec 20, 2014 at 6:20 PM, Hans de Goede <hdegoede@redhat.com>
>> wrote:
>>>
>>> Hi,
>>>
>>>
>>> On 19-12-14 19:17, Maxime Ripard wrote:
>>>>
>>>>
>>>> Hi,
>>>>
>>>> On Thu, Dec 18, 2014 at 09:50:26AM +0100, Hans de Goede wrote:
>>>>>
>>>>>
>>>>> Hi,
>>>>>
>>>>> On 18-12-14 03:48, Chen-Yu Tsai wrote:
>>>>>>
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> On Thu, Dec 18, 2014 at 1:18 AM, Hans de Goede <hdegoede@redhat.com>
>>>>>> wrote:
>>>>>>>
>>>>>>>
>>>>>>> On sun6i the cir block is attached to the reset controller, add
>>>>>>> support
>>>>>>> for de-asserting the reset if a reset controller is specified in dt.
>>>>>>>
>>>>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>>>>> Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
>>>>>>> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
>>>>>>> ---
>>>>>>>    .../devicetree/bindings/media/sunxi-ir.txt         |  2 ++
>>>>>>>    drivers/media/rc/sunxi-cir.c                       | 25
>>>>>>> ++++++++++++++++++++--
>>>>>>>    2 files changed, 25 insertions(+), 2 deletions(-)
>>>>>>>
>>>>>>> diff --git a/Documentation/devicetree/bindings/media/sunxi-ir.txt
>>>>>>> b/Documentation/devicetree/bindings/media/sunxi-ir.txt
>>>>>>> index 23dd5ad..6b70b9b 100644
>>>>>>> --- a/Documentation/devicetree/bindings/media/sunxi-ir.txt
>>>>>>> +++ b/Documentation/devicetree/bindings/media/sunxi-ir.txt
>>>>>>> @@ -10,6 +10,7 @@ Required properties:
>>>>>>>
>>>>>>>    Optional properties:
>>>>>>>    - linux,rc-map-name : Remote control map name.
>>>>>>> +- resets : phandle + reset specifier pair
>>>>>>
>>>>>>
>>>>>>
>>>>>> Should it be optional? Or should we use a sun6i compatible with
>>>>>> a mandatory reset phandle? I mean, the driver/hardware is not
>>>>>> going to work with the reset missing on sun6i.
>>>>>>
>>>>>> Seems we are doing it one way for some of our drivers, and
>>>>>> the other (optional) way for more generic ones, like USB.
>>>>>
>>>>>
>>>>>
>>>>> I do not believe that we should add a new compatible just because
>>>>> the reset line of a block is hooked up differently. It is the
>>>>> exact same ip-block. Only now the reset is not controlled
>>>>> through the apb-gate, but controlled separately.
>>>>
>>>>
>>>>
>>>> He has a point though. Your driver might very well probe nicely and
>>>> everything, but still wouldn't be functional at all because the reset
>>>> line wouldn't have been specified in the DT.
>>>
>>>
>>>
>>> Right, just like other drivers we've, see e.g.:
>>>
>>> Documentation/devicetree/bindings/mmc/sunxi-mmc.txt
>>>
>>> Which is dealing with this in the same way.
>>>
>>>> The easiest way to deal with that would be in the bindings doc to
>>>> update it with a compatible for the A31, and mentionning that the
>>>> reset property is mandatory there.
>>>
>>>
>>>
>>> No the easiest way to deal with this is to expect people writing
>>> the dts to know what they are doing, just like we do for a lot
>>> of the other blocks in sun6i.
>>>
>>> Maybe put a generic note somewhere that sun6i has a reset controller,
>>> and that for all the blocks with optional resets property it should
>>> be considered mandatory on sun6i ?
>>>
>>> I'm sorry but I'm not going to make this change for the ir bindings
>>> given that we've the same situation in a lot of other places.
>>>
>>> Consistency is important. Moreover I believe that having a sun6i
>>> specific compatible string is just wrong, since it is the exact
>>> same hardware block as on sun5i, just with its reset line routed
>>> differently, just like e.g. the mmc controller, the uarts or the gmac
>>> all of which also do not have a sun6i specific compatible to enforce
>>> reset controller usage.
>>>
>>> Regards,
>>>
>>> Hans
>>>
>>>
>>>
>>>
>>>> Note that the code itself might not change at all though. I'd just
>>>> like to avoid any potential breaking of the DT bindings themselves. If
>>>> we further want to refine the code, we can do that however we want.
>>>>
>>>> I have a slight preference for a clean error if reset is missing, but
>>>> I won't get in the way just for that.
>>
>>
>> Seems this patch and the following patch were overlooked after the
>> discussion. Any chance we could get this in?
>
>
> I'm a linux/media sub-maintainer, so I've already send a pull-req for
> these 2 to the linux/media maintainer, iow this is taken care of :)

That's good to hear. I was going through the mainlining effort page,
and couldn't find these 2 in linux-next. I'll mark them as planned
for 3.20 then.


Chen-Yu
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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/media/sunxi-ir.txt b/Documentation/devicetree/bindings/media/sunxi-ir.txt
index 23dd5ad..6b70b9b 100644
--- a/Documentation/devicetree/bindings/media/sunxi-ir.txt
+++ b/Documentation/devicetree/bindings/media/sunxi-ir.txt
@@ -10,6 +10,7 @@  Required properties:
 
 Optional properties:
 - linux,rc-map-name : Remote control map name.
+- resets : phandle + reset specifier pair
 
 Example:
 
@@ -17,6 +18,7 @@  ir0: ir@01c21800 {
 	compatible = "allwinner,sun4i-a10-ir";
 	clocks = <&apb0_gates 6>, <&ir0_clk>;
 	clock-names = "apb", "ir";
+	resets = <&apb0_rst 1>;
 	interrupts = <0 5 1>;
 	reg = <0x01C21800 0x40>;
 	linux,rc-map-name = "rc-rc6-mce";
diff --git a/drivers/media/rc/sunxi-cir.c b/drivers/media/rc/sunxi-cir.c
index 340f7f5..06170e0 100644
--- a/drivers/media/rc/sunxi-cir.c
+++ b/drivers/media/rc/sunxi-cir.c
@@ -23,6 +23,7 @@ 
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/of_platform.h>
+#include <linux/reset.h>
 #include <media/rc-core.h>
 
 #define SUNXI_IR_DEV "sunxi-ir"
@@ -95,6 +96,7 @@  struct sunxi_ir {
 	int             irq;
 	struct clk      *clk;
 	struct clk      *apb_clk;
+	struct reset_control *rst;
 	const char      *map_name;
 };
 
@@ -166,15 +168,29 @@  static int sunxi_ir_probe(struct platform_device *pdev)
 		return PTR_ERR(ir->clk);
 	}
 
+	/* Reset (optional) */
+	ir->rst = devm_reset_control_get_optional(dev, NULL);
+	if (IS_ERR(ir->rst)) {
+		ret = PTR_ERR(ir->rst);
+		if (ret == -EPROBE_DEFER)
+			return ret;
+		ir->rst = NULL;
+	} else {
+		ret = reset_control_deassert(ir->rst);
+		if (ret)
+			return ret;
+	}
+
 	ret = clk_set_rate(ir->clk, SUNXI_IR_BASE_CLK);
 	if (ret) {
 		dev_err(dev, "set ir base clock failed!\n");
-		return ret;
+		goto exit_reset_assert;
 	}
 
 	if (clk_prepare_enable(ir->apb_clk)) {
 		dev_err(dev, "try to enable apb_ir_clk failed\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto exit_reset_assert;
 	}
 
 	if (clk_prepare_enable(ir->clk)) {
@@ -271,6 +287,9 @@  exit_clkdisable_clk:
 	clk_disable_unprepare(ir->clk);
 exit_clkdisable_apb_clk:
 	clk_disable_unprepare(ir->apb_clk);
+exit_reset_assert:
+	if (ir->rst)
+		reset_control_assert(ir->rst);
 
 	return ret;
 }
@@ -282,6 +301,8 @@  static int sunxi_ir_remove(struct platform_device *pdev)
 
 	clk_disable_unprepare(ir->clk);
 	clk_disable_unprepare(ir->apb_clk);
+	if (ir->rst)
+		reset_control_assert(ir->rst);
 
 	spin_lock_irqsave(&ir->ir_lock, flags);
 	/* disable IR IRQ */