[PATCH resend 2/6] clk: sunxi: Add VE (Video Engine) module clock driver for sun[457]i

[Chen-Yu Tsai]

On Tue, Dec 8, 2015 at 6:02 PM, Maxime Ripard
<maxime.ripard at free-electrons.com> wrote:
> Hi,
>
> On Sat, Dec 05, 2015 at 09:16:43PM +0800, Chen-Yu Tsai wrote:
>> The video engine has its own special module clock, consisting of a clock
>> gate, configurable dividers, and a reset control.
>>
>> On later (sun[68]i) families, the reset control is moved out of this
>> piece of hardware and grouped with reset controls of other peripherals.
>>
>> Signed-off-by: Chen-Yu Tsai <wens at csie.org>
>> ---
>>  Documentation/devicetree/bindings/clock/sunxi.txt |   4 +
>>  drivers/clk/sunxi/Makefile                        |   1 +
>>  drivers/clk/sunxi/clk-a10-ve.c                    | 171 ++++++++++++++++++++++
>>  3 files changed, 176 insertions(+)
>>  create mode 100644 drivers/clk/sunxi/clk-a10-ve.c
>>
>> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
>> index ef0b452806b1..14496056319f 100644
>> --- a/Documentation/devicetree/bindings/clock/sunxi.txt
>> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
>> @@ -74,6 +74,7 @@ Required properties:
>>       "allwinner,sun8i-h3-usb-clk" - for usb gates + resets on H3
>>       "allwinner,sun9i-a80-usb-mod-clk" - for usb gates + resets on A80
>>       "allwinner,sun9i-a80-usb-phy-clk" - for usb phy gates + resets on A80
>> +     "allwinner,sun4i-a10-ve-clk" - for the Video Engine clock
>>
>>  Required properties for all clocks:
>>  - reg : shall be the control register address for the clock.
>> @@ -93,6 +94,9 @@ Required properties for all clocks:
>>  And "allwinner,*-usb-clk" clocks also require:
>>  - reset-cells : shall be set to 1
>>
>> +The "allwinner,sun4i-a10-ve-clk" clock also requires:
>> +- reset-cells : shall be set to 0
>> +
>>  The "allwinner,sun9i-a80-mmc-config-clk" clock also requires:
>>  - #reset-cells : shall be set to 1
>>  - resets : shall be the reset control phandle for the mmc block.
>> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
>> index 103efab05ca8..78db91ad5af6 100644
>> --- a/drivers/clk/sunxi/Makefile
>> +++ b/drivers/clk/sunxi/Makefile
>> @@ -7,6 +7,7 @@ obj-y += clk-a10-codec.o
>>  obj-y += clk-a10-hosc.o
>>  obj-y += clk-a10-mod1.o
>>  obj-y += clk-a10-pll2.o
>> +obj-y += clk-a10-ve.o
>>  obj-y += clk-a20-gmac.o
>>  obj-y += clk-mod0.o
>>  obj-y += clk-simple-gates.o
>> diff --git a/drivers/clk/sunxi/clk-a10-ve.c b/drivers/clk/sunxi/clk-a10-ve.c
>> new file mode 100644
>> index 000000000000..de0fdb656150
>> --- /dev/null
>> +++ b/drivers/clk/sunxi/clk-a10-ve.c
>> @@ -0,0 +1,171 @@
>> +/*
>> + * Copyright 2015 Chen-Yu Tsai
>> + *
>> + * Chen-Yu Tsai <wens at csie.org>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/clk-provider.h>
>> +#include <linux/of.h>
>> +#include <linux/of_address.h>
>> +#include <linux/reset-controller.h>
>> +#include <linux/slab.h>
>> +#include <linux/spinlock.h>
>> +
>> +static DEFINE_SPINLOCK(ve_lock);
>> +
>> +#define SUN4I_VE_ENABLE              31
>> +#define SUN4I_VE_DIVIDER_SHIFT       16
>> +#define SUN4I_VE_DIVIDER_WIDTH       3
>> +#define SUN4I_VE_RESET               0
>> +
>> +/**
>> + * sunxi_ve_reset... - reset bit in ve clk registers handling
>> + */
>> +
>> +struct ve_reset_data {
>> +     void __iomem                    *reg;
>> +     spinlock_t                      *lock;
>> +     struct reset_controller_dev     rcdev;
>> +};
>> +
>> +static int sunxi_ve_reset_assert(struct reset_controller_dev *rcdev,
>> +                              unsigned long id)
>> +{
>> +     struct ve_reset_data *data = container_of(rcdev,
>> +                                               struct ve_reset_data,
>> +                                               rcdev);
>> +     unsigned long flags;
>> +     u32 reg;
>> +
>> +     spin_lock_irqsave(data->lock, flags);
>> +
>> +     reg = readl(data->reg);
>> +     writel(reg & ~BIT(SUN4I_VE_RESET), data->reg);
>> +
>> +     spin_unlock_irqrestore(data->lock, flags);
>> +
>> +     return 0;
>> +}
>> +
>> +static int sunxi_ve_reset_deassert(struct reset_controller_dev *rcdev,
>> +                                unsigned long id)
>> +{
>> +     struct ve_reset_data *data = container_of(rcdev,
>> +                                               struct ve_reset_data,
>> +                                               rcdev);
>> +     unsigned long flags;
>> +     u32 reg;
>> +
>> +     spin_lock_irqsave(data->lock, flags);
>> +
>> +     reg = readl(data->reg);
>> +     writel(reg | BIT(SUN4I_VE_RESET), data->reg);
>> +
>> +     spin_unlock_irqrestore(data->lock, flags);
>> +
>> +     return 0;
>> +}
>
> Is it me, or do we have this code duplicated everywhere now?
>
> Maybe we should turn this into a small library.

I agree.

>> +static int sunxi_ve_of_xlate(struct reset_controller_dev *rcdev,
>> +                          const struct of_phandle_args *reset_spec)
>> +{
>> +    if (WARN_ON(reset_spec->args_count != 0))
>> +     return -EINVAL;
>> +
>> +    return 0;
>> +}
>
> And this could be part of the reset controller framework too.

I looked around, and we seem to be the only one with #reset-cells = <0>.

> Anyway, both these comments can be fixed by a later patch. Can you
> take care of this?

Sure. I make some patches.

> I've fixed the white space issue, and applied your patch.
>
> (and added Jens Tested-by)
>
> Thanks!
> Maxime

Thanks!

ChenYu