Re: [PATCH] clk: qcom: sc8280xp: add parent to gcc_ufs_phy_axi_clk for sa8540p

[Andrew Halaney <ahalaney@redhat.com>]

On Thu, Jun 23, 2022 at 10:28:37AM -0400, Brian Masney wrote:
> The sa8540p automotive board has the same SOC as the sc8280xp. In order
> to get the first UFS controller working on the sa8540p,
> GCC_UFS_REF_CLKREF_CLK needs to be setup as a parent to
> GCC_UFS_PHY_AXI_CLK.
> 
> This clock name came from the DTS for the downstream MSM 5.4 kernel
> sources for the sa8540p. It also references GCC_UFS_CARD_CLKREF_CLK,
> however that wasn't needed to get the first UFS controller working.
> 

I'm not knowledgable enough on the clock subsystem or have access to
documentation to comment on correctness outside of the 5.4 MSM kernel
you mentioned, but I think this probably deserves a Fixes: tag?

I can at least also comment that without this change the sa8540p doesn't
boot on the QDrive3 boards we have.

Thanks,
Andrew

> Signed-off-by: Brian Masney <bmasney@redhat.com>
> ---
> I originally added this under GCC_UFS_PHY_PHY_AUX_CLK since that's
> what's in the downstream DTS. I was getting errors about
> GCC_UFS_PHY_AXI_CLK being stuck at off so I moved it there.
> 
> Also I don't have access to any documentation for this board so I'm
> hoping that someone with docs access can verify that this is the
> appropriate place to put this.
> 
>  drivers/clk/qcom/gcc-sc8280xp.c | 27 ++++++++++++++-------------
>  1 file changed, 14 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/clk/qcom/gcc-sc8280xp.c b/drivers/clk/qcom/gcc-sc8280xp.c
> index 4b894442fdf5..4639b50da418 100644
> --- a/drivers/clk/qcom/gcc-sc8280xp.c
> +++ b/drivers/clk/qcom/gcc-sc8280xp.c
> @@ -5685,6 +5685,19 @@ static struct clk_branch gcc_ufs_phy_ahb_clk = {
>  	},
>  };
>  
> +static struct clk_branch gcc_ufs_ref_clkref_clk = {
> +	.halt_reg = 0x8c058,
> +	.halt_check = BRANCH_HALT,
> +	.clkr = {
> +		.enable_reg = 0x8c058,
> +		.enable_mask = BIT(0),
> +		.hw.init = &(const struct clk_init_data) {
> +			.name = "gcc_ufs_ref_clkref_clk",
> +			.ops = &clk_branch2_ops,
> +		},
> +	},
> +};
> +
>  static struct clk_branch gcc_ufs_phy_axi_clk = {
>  	.halt_reg = 0x77010,
>  	.halt_check = BRANCH_HALT_VOTED,
> @@ -5696,6 +5709,7 @@ static struct clk_branch gcc_ufs_phy_axi_clk = {
>  		.hw.init = &(const struct clk_init_data) {
>  			.name = "gcc_ufs_phy_axi_clk",
>  			.parent_hws = (const struct clk_hw*[]){
> +				&gcc_ufs_ref_clkref_clk.clkr.hw,
>  				&gcc_ufs_phy_axi_clk_src.clkr.hw,
>  			},
>  			.num_parents = 1,
> @@ -5899,19 +5913,6 @@ static struct clk_branch gcc_ufs_phy_unipro_core_hw_ctl_clk = {
>  	},
>  };
>  
> -static struct clk_branch gcc_ufs_ref_clkref_clk = {
> -	.halt_reg = 0x8c058,
> -	.halt_check = BRANCH_HALT,
> -	.clkr = {
> -		.enable_reg = 0x8c058,
> -		.enable_mask = BIT(0),
> -		.hw.init = &(const struct clk_init_data) {
> -			.name = "gcc_ufs_ref_clkref_clk",
> -			.ops = &clk_branch2_ops,
> -		},
> -	},
> -};
> -
>  static struct clk_branch gcc_usb2_hs0_clkref_clk = {
>  	.halt_reg = 0x8c044,
>  	.halt_check = BRANCH_HALT,
> -- 
> 2.36.1
>