Re: [PATCH v7 2/3] PCI: rockchip: Simplify reset control handling by using reset_control_bulk*() function

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Sat, Oct 12, 2024 at 10:36:04AM +0530, Anand Moon wrote:
> Refactor the reset control handling in the Rockchip PCIe driver,
> introducing a more robust and efficient method for assert and
> deassert reset controller using reset_control_bulk*() API. Using the
> reset_control_bulk APIs, the reset handling for the core clocks reset
> unit becomes much simpler.
> 

Same comments as previous patch.

> Spilt the reset controller in two groups as pre the RK3399 TRM.

*per

Also please state the TRM name and section for reference.

> After power up, the software driver should de-assert the reset of PCIe PHY,
> then wait the PLL locked by polling the status, if PLL
> has locked, then can de-assert the reset simultaneously
> driver need to De-assert the reset pins simultionaly.
> 
>   PIPE_RESET_N/MGMT_STICKY_RESET_N/MGMT_RESET_N/RESET_N.
> 
> - replace devm_reset_control_get_exclusive() with
> 	devm_reset_control_bulk_get_exclusive().
> - replace reset_control_assert with
> 	reset_control_bulk_assert().
> - replace reset_control_deassert with
> 	reset_control_bulk_deassert().
> 
> Signed-off-by: Anand Moon <linux.amoon@gmail.com>
> ---
> v7: replace devm_reset_control_bulk_get_optional_exclusive()
>         with devm_reset_control_bulk_get_exclusive()
>     update the functional changes.
> V6: Add reason for the split of the RESET pins.
> v5: Fix the De-assert reset core as per the TRM
>     De-assert the PIPE_RESET_N/MGMT_STICKY_RESET_N/MGMT_RESET_N/RESET_N
>     simultaneously.
> v4: use dev_err_probe in error path.
> v3: Fix typo in commit message, dropped reported by.
> v2: Fix compilation error reported by Intel test robot
>     fixed checkpatch warning.
> ---
>  drivers/pci/controller/pcie-rockchip.c | 151 +++++--------------------
>  drivers/pci/controller/pcie-rockchip.h |  26 +++--
>  2 files changed, 49 insertions(+), 128 deletions(-)
> 
> diff --git a/drivers/pci/controller/pcie-rockchip.c b/drivers/pci/controller/pcie-rockchip.c
> index 2777ef0cb599..9a118e2b8cbd 100644
> --- a/drivers/pci/controller/pcie-rockchip.c
> +++ b/drivers/pci/controller/pcie-rockchip.c
> @@ -30,7 +30,7 @@ int rockchip_pcie_parse_dt(struct rockchip_pcie *rockchip)

[...]

> +	err = reset_control_bulk_assert(ROCKCHIP_NUM_PM_RSTS,
> +					rockchip->pm_rsts);
> +	if (err)
> +		return dev_err_probe(dev, err, "reset bulk assert pm reset\n");

'Couldn't assert PM resets'

>  
>  	for (i = 0; i < MAX_LANE_NUM; i++) {
>  		err = phy_init(rockchip->phys[i]);
> @@ -173,47 +128,17 @@ int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
>  		}
>  	}
>  
> -	err = reset_control_assert(rockchip->core_rst);
> -	if (err) {
> -		dev_err(dev, "assert core_rst err %d\n", err);
> -		goto err_exit_phy;
> -	}
> -
> -	err = reset_control_assert(rockchip->mgmt_rst);
> -	if (err) {
> -		dev_err(dev, "assert mgmt_rst err %d\n", err);
> -		goto err_exit_phy;
> -	}
> -
> -	err = reset_control_assert(rockchip->mgmt_sticky_rst);
> -	if (err) {
> -		dev_err(dev, "assert mgmt_sticky_rst err %d\n", err);
> -		goto err_exit_phy;
> -	}
> -
> -	err = reset_control_assert(rockchip->pipe_rst);
> -	if (err) {
> -		dev_err(dev, "assert pipe_rst err %d\n", err);
> -		goto err_exit_phy;
> -	}
> +	err = reset_control_bulk_assert(ROCKCHIP_NUM_CORE_RSTS,
> +					rockchip->core_rsts);
> +	if (err)
> +		return dev_err_probe(dev, err, "reset bulk assert core reset\n");

'Couldn't assert Core resets'

>  
>  	udelay(10);
>  
> -	err = reset_control_deassert(rockchip->pm_rst);
> -	if (err) {
> -		dev_err(dev, "deassert pm_rst err %d\n", err);
> -		goto err_exit_phy;
> -	}
> -
> -	err = reset_control_deassert(rockchip->aclk_rst);
> +	err = reset_control_bulk_deassert(ROCKCHIP_NUM_PM_RSTS,
> +					  rockchip->pm_rsts);
>  	if (err) {
> -		dev_err(dev, "deassert aclk_rst err %d\n", err);
> -		goto err_exit_phy;
> -	}
> -
> -	err = reset_control_deassert(rockchip->pclk_rst);
> -	if (err) {
> -		dev_err(dev, "deassert pclk_rst err %d\n", err);
> +		dev_err(dev, "reset bulk deassert pm err %d\n", err);

'Couldn't deassert PM resets'

>  		goto err_exit_phy;
>  	}
>  
> @@ -256,31 +181,15 @@ int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
>  	 * Please don't reorder the deassert sequence of the following
>  	 * four reset pins.

I don't think my earlier comment on this addressed. Why are you changing the
reset order? Why can't you have the resets in below (older) order?

static const char * const rockchip_pci_core_rsts[] = {
	mgmt-sticky",
	"core",
	"mgmt",
	"pipe",
};

Also, this comment should be removed now.

>  	 */
> -	err = reset_control_deassert(rockchip->mgmt_sticky_rst);
> -	if (err) {
> -		dev_err(dev, "deassert mgmt_sticky_rst err %d\n", err);
> -		goto err_power_off_phy;
> -	}
> -
> -	err = reset_control_deassert(rockchip->core_rst);
> +	err = reset_control_bulk_deassert(ROCKCHIP_NUM_CORE_RSTS,
> +					  rockchip->core_rsts);
>  	if (err) {
> -		dev_err(dev, "deassert core_rst err %d\n", err);
> -		goto err_power_off_phy;
> -	}
> -
> -	err = reset_control_deassert(rockchip->mgmt_rst);
> -	if (err) {
> -		dev_err(dev, "deassert mgmt_rst err %d\n", err);
> -		goto err_power_off_phy;
> -	}
> -
> -	err = reset_control_deassert(rockchip->pipe_rst);
> -	if (err) {
> -		dev_err(dev, "deassert pipe_rst err %d\n", err);
> +		dev_err(dev, "reset bulk deassert core err %d\n", err);

'Couldn't deassert Core resets'

- Mani

-- 
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