[2/5] clk: qcom: Allow custom reset ops

Add support to allow soc specific clk drivers to specify a custom reset
operation. A consumer-driver of the reset framework can call
"reset_control_reset()" api to trigger this.

Signed-off-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
---

 drivers/clk/qcom/reset.c | 6 ++++++
 drivers/clk/qcom/reset.h | 2 ++
 2 files changed, 8 insertions(+)

Hi Akhil,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on clk/clk-next]
[also build test WARNING on robh/for-next drm-misc/drm-misc-next drm-tip/drm-tip linus/master v5.19-rc8 next-20220728]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Akhil-P-Oommen/clk-qcom-Support-gdsc-collapse-polling-using-reset-inteface/20220730-171922
base:   https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git clk-next
config: ia64-randconfig-r031-20220729 (https://download.01.org/0day-ci/archive/20220730/202207302137.mPbHPaHz-lkp@intel.com/config)
compiler: ia64-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/971a03493e9854ff4a227ee4d80b533997959891
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Akhil-P-Oommen/clk-qcom-Support-gdsc-collapse-polling-using-reset-inteface/20220730-171922
        git checkout 971a03493e9854ff4a227ee4d80b533997959891
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=ia64 SHELL=/bin/bash drivers/clk/qcom/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   drivers/clk/qcom/reset.c: In function 'qcom_reset':
>> drivers/clk/qcom/reset.c:17:9: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
      17 |         const struct qcom_reset_map *map = &rst->reset_map[id];
         |         ^~~~~


vim +17 drivers/clk/qcom/reset.c

    13	
    14	static int qcom_reset(struct reset_controller_dev *rcdev, unsigned long id)
    15	{
    16		struct qcom_reset_controller *rst = to_qcom_reset_controller(rcdev);
  > 17		const struct qcom_reset_map *map = &rst->reset_map[id];
    18	
    19		if (map->op)
    20			return map->op(map);
    21	
    22		rcdev->ops->assert(rcdev, id);
    23		udelay(1);
    24		rcdev->ops->deassert(rcdev, id);
    25		return 0;
    26	}
    27

On 7/30/2022 6:40 PM, kernel test robot wrote:
> Hi Akhil,
>
> Thank you for the patch! Perhaps something to improve:
>
> [auto build test WARNING on clk/clk-next]
> [also build test WARNING on robh/for-next drm-misc/drm-misc-next drm-tip/drm-tip linus/master v5.19-rc8 next-20220728]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url:    https://github.com/intel-lab-lkp/linux/commits/Akhil-P-Oommen/clk-qcom-Support-gdsc-collapse-polling-using-reset-inteface/20220730-171922
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git clk-next
> config: ia64-randconfig-r031-20220729 (https://download.01.org/0day-ci/archive/20220730/202207302137.mPbHPaHz-lkp@intel.com/config)
> compiler: ia64-linux-gcc (GCC) 12.1.0
> reproduce (this is a W=1 build):
>          wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>          chmod +x ~/bin/make.cross
>          # https://github.com/intel-lab-lkp/linux/commit/971a03493e9854ff4a227ee4d80b533997959891
>          git remote add linux-review https://github.com/intel-lab-lkp/linux
>          git fetch --no-tags linux-review Akhil-P-Oommen/clk-qcom-Support-gdsc-collapse-polling-using-reset-inteface/20220730-171922
>          git checkout 971a03493e9854ff4a227ee4d80b533997959891
>          # save the config file
>          mkdir build_dir && cp config build_dir/.config
>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=ia64 SHELL=/bin/bash drivers/clk/qcom/
>
> If you fix the issue, kindly add following tag where applicable
> Reported-by: kernel test robot <lkp@intel.com>
>
> All warnings (new ones prefixed by >>):
>
>     drivers/clk/qcom/reset.c: In function 'qcom_reset':
>>> drivers/clk/qcom/reset.c:17:9: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
>        17 |         const struct qcom_reset_map *map = &rst->reset_map[id];
>           |         ^~~~~
>
>
> vim +17 drivers/clk/qcom/reset.c
>
>      13	
>      14	static int qcom_reset(struct reset_controller_dev *rcdev, unsigned long id)
>      15	{
>      16		struct qcom_reset_controller *rst = to_qcom_reset_controller(rcdev);
>    > 17		const struct qcom_reset_map *map = &rst->reset_map[id];
>      18	
>      19		if (map->op)
>      20			return map->op(map);
>      21	
>      22		rcdev->ops->assert(rcdev, id);
>      23		udelay(1);
>      24		rcdev->ops->deassert(rcdev, id);
>      25		return 0;
>      26	}
>      27	
>
Will fix this and send another version of this patch. Please let me know 
if there is any feedback to the whole series.

-Akhil.

On 30/07/2022 12:17, Akhil P Oommen wrote:
> Add support to allow soc specific clk drivers to specify a custom reset
> operation. A consumer-driver of the reset framework can call
> "reset_control_reset()" api to trigger this.
> 
> Signed-off-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
> ---
> 
>   drivers/clk/qcom/reset.c | 6 ++++++
>   drivers/clk/qcom/reset.h | 2 ++
>   2 files changed, 8 insertions(+)
> 
> diff --git a/drivers/clk/qcom/reset.c b/drivers/clk/qcom/reset.c
> index 819d194..4782bf1 100644
> --- a/drivers/clk/qcom/reset.c
> +++ b/drivers/clk/qcom/reset.c
> @@ -13,6 +13,12 @@
>   
>   static int qcom_reset(struct reset_controller_dev *rcdev, unsigned long id)
>   {
> +	struct qcom_reset_controller *rst = to_qcom_reset_controller(rcdev);
> +	const struct qcom_reset_map *map = &rst->reset_map[id];
> +
> +	if (map->op)
> +		return map->op(map);

This looks like a hack. For example, assert() and deassert() would still 
follow the usual pattern of updating the bits. Please at least make them 
return -EOPNOTSUP if map->op is defined.

A slightly better solution would be to make qcom_reset implementation 
optional (and depending on desc->num_resets being greater than 0). Then 
you can register your own reset controller implementation from the gpucc 
driver.


> +
>   	rcdev->ops->assert(rcdev, id);
>   	udelay(1);
>   	rcdev->ops->deassert(rcdev, id);
> diff --git a/drivers/clk/qcom/reset.h b/drivers/clk/qcom/reset.h
> index 2a08b5e..295deeb 100644
> --- a/drivers/clk/qcom/reset.h
> +++ b/drivers/clk/qcom/reset.h
> @@ -11,6 +11,8 @@
>   struct qcom_reset_map {
>   	unsigned int reg;
>   	u8 bit;
> +	int (*op)(const struct qcom_reset_map *map);
> +	void *priv;
>   };
>   
>   struct regmap;