diff mbox series

[v2,13/15] phy: qcom-qmp-pcie: add support for pipediv2 clock

Message ID 20221019113552.22353-14-johan+linaro@kernel.org
State New
Headers show
Series phy: qcom-qmp-pcie: add support for sc8280xp | expand

Commit Message

Johan Hovold Oct. 19, 2022, 11:35 a.m. UTC
Some QMP PHYs have a second fixed-divider pipe clock that needs to be
enabled along with the pipe clock.

Add support for an optional "pipediv2" clock.

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 42 ++++++++++++++++++++----
 1 file changed, 36 insertions(+), 6 deletions(-)

Comments

Dmitry Baryshkov Oct. 20, 2022, 8:31 a.m. UTC | #1
On 19/10/2022 14:35, Johan Hovold wrote:
> Some QMP PHYs have a second fixed-divider pipe clock that needs to be
> enabled along with the pipe clock.
> 
> Add support for an optional "pipediv2" clock.
> 
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>   drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 42 ++++++++++++++++++++----
>   1 file changed, 36 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> index 9c8e009033f1..c1d74c06fad1 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> @@ -1379,7 +1379,9 @@ struct qmp_pcie {
>   	void __iomem *rx2;
>   
>   	struct clk *pipe_clk;
> +	struct clk *pipediv2_clk;
>   	struct clk_bulk_data *clks;
> +
>   	struct reset_control_bulk_data *resets;
>   	struct regulator_bulk_data *vregs;
>   
> @@ -1902,6 +1904,36 @@ static int qmp_pcie_exit(struct phy *phy)
>   	return 0;
>   }
>   
> +static int pipe_clk_enable(struct qmp_pcie *qmp)
> +{
> +	int ret;
> +
> +	ret = clk_prepare_enable(qmp->pipe_clk);
> +	if (ret) {
> +		dev_err(qmp->dev, "failed to enable pipe clock: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = clk_prepare_enable(qmp->pipediv2_clk);
> +	if (ret) {
> +		dev_err(qmp->dev, "failed to enable pipediv2 clock: %d\n", ret);
> +		goto err_disable_pipe_clk;
> +	}
> +
> +	return 0;
> +
> +err_disable_pipe_clk:
> +	clk_disable_unprepare(qmp->pipe_clk);
> +
> +	return ret;
> +}
> +
> +static void pipe_clk_disable(struct qmp_pcie *qmp)
> +{
> +	clk_disable_unprepare(qmp->pipediv2_clk);
> +	clk_disable_unprepare(qmp->pipe_clk);
> +}
> +
>   static int qmp_pcie_power_on(struct phy *phy)
>   {
>   	struct qmp_pcie *qmp = phy_get_drvdata(phy);
> @@ -1923,11 +1955,9 @@ static int qmp_pcie_power_on(struct phy *phy)
>   	qmp_pcie_init_registers(qmp, &cfg->tables);
>   	qmp_pcie_init_registers(qmp, mode_tables);
>   
> -	ret = clk_prepare_enable(qmp->pipe_clk);
> -	if (ret) {
> -		dev_err(qmp->dev, "pipe_clk enable failed err=%d\n", ret);
> +	ret = pipe_clk_enable(qmp);
> +	if (ret)
>   		return ret;
> -	}
>   
>   	/* Pull PHY out of reset state */
>   	qphy_clrbits(pcs, cfg->regs[QPHY_SW_RESET], SW_RESET);
> @@ -1950,7 +1980,7 @@ static int qmp_pcie_power_on(struct phy *phy)
>   	return 0;
>   
>   err_disable_pipe_clk:
> -	clk_disable_unprepare(qmp->pipe_clk);
> +	pipe_clk_disable(qmp);
>   
>   	return ret;
>   }
> @@ -1960,7 +1990,7 @@ static int qmp_pcie_power_off(struct phy *phy)
>   	struct qmp_pcie *qmp = phy_get_drvdata(phy);
>   	const struct qmp_phy_cfg *cfg = qmp->cfg;
>   
> -	clk_disable_unprepare(qmp->pipe_clk);
> +	pipe_clk_disable(qmp);
>   
>   	/* PHY reset */
>   	qphy_setbits(qmp->pcs, cfg->regs[QPHY_SW_RESET], SW_RESET);

I still think that the attached patch is somewhat simpler. Diffstat 
supports that idea:

$ diffstat /tmp/pipe.diff
  phy-qcom-qmp-pcie.c |   26 ++++++++++++++++----------
  1 file changed, 16 insertions(+), 10 deletions(-)

Yes, I'm speaking this after having cleaned up several open-coded 
versions of clk_bulk_foo from the drm/msm code. It typically starts with 
the 'just another clock' story, and then suddenly they are all over the 
code.
Dmitry Baryshkov Oct. 20, 2022, 9:28 a.m. UTC | #2
On 20/10/2022 12:05, Johan Hovold wrote:
> On Thu, Oct 20, 2022 at 11:31:35AM +0300, Dmitry Baryshkov wrote:
>> On 19/10/2022 14:35, Johan Hovold wrote:
>>> Some QMP PHYs have a second fixed-divider pipe clock that needs to be
>>> enabled along with the pipe clock.
>>>
>>> Add support for an optional "pipediv2" clock.
>>>
>>> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
>>> ---
>>>    drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 42 ++++++++++++++++++++----
>>>    1 file changed, 36 insertions(+), 6 deletions(-)
> 
>> I still think that the attached patch is somewhat simpler. Diffstat
>> supports that idea:
>>
>> $ diffstat /tmp/pipe.diff
>>    phy-qcom-qmp-pcie.c |   26 ++++++++++++++++----------
>>    1 file changed, 16 insertions(+), 10 deletions(-)
> 
> It's not just about LoC.
>   
>> Yes, I'm speaking this after having cleaned up several open-coded
>> versions of clk_bulk_foo from the drm/msm code. It typically starts with
>> the 'just another clock' story, and then suddenly they are all over the
>> code.
> 
> But you don't start using the bulk API when you have one clock. Two,
> maybe. Three, sure. It's a decision that needs to be done on a case-by
> case basis, and pipe clocks for the QMP block is different from general
> interface clocks (which are more likely to be extended). (And of course
> the clocks would need to be independent in the first place.)
> 
> Here's your example diff inline:
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> index 9c8e009033f1..a148b143dd90 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> @@ -1378,8 +1378,10 @@ struct qmp_pcie {
>   	void __iomem *tx2;
>   	void __iomem *rx2;
>   
> -	struct clk *pipe_clk;
> +	struct clk_bulk_data *pipe_clks;
> +	int num_pipe_clks;
>   	struct clk_bulk_data *clks;
> +
>   	struct reset_control_bulk_data *resets;
>   	struct regulator_bulk_data *vregs;
>   
> @@ -1923,11 +1925,9 @@ static int qmp_pcie_power_on(struct phy *phy)
>   	qmp_pcie_init_registers(qmp, &cfg->tables);
>   	qmp_pcie_init_registers(qmp, mode_tables);
>   
> -	ret = clk_prepare_enable(qmp->pipe_clk);
> -	if (ret) {
> -		dev_err(qmp->dev, "pipe_clk enable failed err=%d\n", ret);
> +	ret = clk_bulk_prepare_enable(qmp->num_pipe_clks, qmp->pipe_clks);
> +	if (ret)
>   		return ret;
> -	}
>   
>   	/* Pull PHY out of reset state */
>   	qphy_clrbits(pcs, cfg->regs[QPHY_SW_RESET], SW_RESET);
> @@ -1950,7 +1950,7 @@ static int qmp_pcie_power_on(struct phy *phy)
>   	return 0;
>   
>   err_disable_pipe_clk:
> -	clk_disable_unprepare(qmp->pipe_clk);
> +	clk_bulk_disable_unprepare(qmp->num_pipe_clks, qmp->pipe_clks);
>   
>   	return ret;
>   }
> @@ -1960,7 +1960,7 @@ static int qmp_pcie_power_off(struct phy *phy)
>   	struct qmp_pcie *qmp = phy_get_drvdata(phy);
>   	const struct qmp_phy_cfg *cfg = qmp->cfg;
>   
> -	clk_disable_unprepare(qmp->pipe_clk);
> +	clk_bulk_disable_unprepare(qmp->num_pipe_clks, qmp->pipe_clks);
>   
>   	/* PHY reset */
>   	qphy_setbits(qmp->pcs, cfg->regs[QPHY_SW_RESET], SW_RESET);
> 
> The above is pretty much identical, expect for using the bulk API
> instead of the very straight-forward pipe-clock helpers.
> 
> @@ -2154,6 +2154,7 @@ static int qmp_pcie_parse_dt_legacy(struct qmp_pcie *qmp, struct device_node *np
>   	struct platform_device *pdev = to_platform_device(qmp->dev);
>   	const struct qmp_phy_cfg *cfg = qmp->cfg;
>   	struct device *dev = qmp->dev;
> +	struct clk *clk;
>   
>   	qmp->serdes = devm_platform_ioremap_resource(pdev, 0);
>   	if (IS_ERR(qmp->serdes))
> @@ -2206,12 +2207,17 @@ static int qmp_pcie_parse_dt_legacy(struct qmp_pcie *qmp, struct device_node *np
>   		}
>   	}
>   
> -	qmp->pipe_clk = devm_get_clk_from_child(dev, np, NULL);
> -	if (IS_ERR(qmp->pipe_clk)) {
> -		return dev_err_probe(dev, PTR_ERR(qmp->pipe_clk),
> +	clk = devm_get_clk_from_child(dev, np, NULL);
> +	if (IS_ERR(clk)) {
> +		return dev_err_probe(dev, PTR_ERR(clk),
>   				     "failed to get pipe clock\n");
>   	}
>   
> +	qmp->num_pipe_clks = 1;
> +	qmp->pipe_clks = devm_kcalloc(dev, qmp->num_pipe_clks,
> +				      sizeof(*qmp->pipe_clks), GFP_KERNEL);
> +	qmp->pipe_clks[0].clk = clk;
> 
> So here you're poking at bulk API internals and forgot to set the id
> string, which the implementation uses.

I didn't forget, I just skipped setting it. Hmm. I thought that it is 
used only for clk_bulk_get. But after checking, it seems it's also used 
for error messages. Mea culpa.

But it's not that I was poking into the internals. These items are in 
the public header.

> 
> For reasons like this, and the fact that will likely never have a third
> pipe clock, I'm reluctant to using the bulk API.

Let's resort to the maintainer opinion then.

> 
> +
>   	return 0;
>   }
>   
> Johan
Dmitry Baryshkov Oct. 20, 2022, 10:53 a.m. UTC | #3
On 20/10/2022 13:49, Johan Hovold wrote:
> On Thu, Oct 20, 2022 at 12:28:14PM +0300, Dmitry Baryshkov wrote:
>> On 20/10/2022 12:05, Johan Hovold wrote:
> 
>>> Here's your example diff inline:
> 
>>> @@ -2206,12 +2207,17 @@ static int qmp_pcie_parse_dt_legacy(struct qmp_pcie *qmp, struct device_node *np
>>>    		}
>>>    	}
>>>    
>>> -	qmp->pipe_clk = devm_get_clk_from_child(dev, np, NULL);
>>> -	if (IS_ERR(qmp->pipe_clk)) {
>>> -		return dev_err_probe(dev, PTR_ERR(qmp->pipe_clk),
>>> +	clk = devm_get_clk_from_child(dev, np, NULL);
>>> +	if (IS_ERR(clk)) {
>>> +		return dev_err_probe(dev, PTR_ERR(clk),
>>>    				     "failed to get pipe clock\n");
>>>    	}
>>>    
>>> +	qmp->num_pipe_clks = 1;
>>> +	qmp->pipe_clks = devm_kcalloc(dev, qmp->num_pipe_clks,
>>> +				      sizeof(*qmp->pipe_clks), GFP_KERNEL);
>>> +	qmp->pipe_clks[0].clk = clk;
>>>
>>> So here you're poking at bulk API internals and forgot to set the id
>>> string, which the implementation uses.
>>
>> I didn't forget, I just skipped setting it. Hmm. I thought that it is
>> used only for clk_bulk_get. But after checking, it seems it's also used
>> for error messages. Mea culpa.
>>
>> But it's not that I was poking into the internals. These items are in
>> the public header.
> 
> My point is that you're not using the bulk API as it was intended (e.g.
> with clk_bulk_get()) and you risk running into issues like the above.
> 
> And looking up the actual clock name for this is overkill, even in the
> case were it is provided, so we'd need to set it unconditionally to
> "pipe" (which is fine).
> 
>>> For reasons like this, and the fact that will likely never have a third
>>> pipe clock, I'm reluctant to using the bulk API.
>>
>> Let's resort to the maintainer opinion then.
> 
> I'll take another look at it too.

Thanks!
diff mbox series

Patch

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
index 9c8e009033f1..c1d74c06fad1 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
@@ -1379,7 +1379,9 @@  struct qmp_pcie {
 	void __iomem *rx2;
 
 	struct clk *pipe_clk;
+	struct clk *pipediv2_clk;
 	struct clk_bulk_data *clks;
+
 	struct reset_control_bulk_data *resets;
 	struct regulator_bulk_data *vregs;
 
@@ -1902,6 +1904,36 @@  static int qmp_pcie_exit(struct phy *phy)
 	return 0;
 }
 
+static int pipe_clk_enable(struct qmp_pcie *qmp)
+{
+	int ret;
+
+	ret = clk_prepare_enable(qmp->pipe_clk);
+	if (ret) {
+		dev_err(qmp->dev, "failed to enable pipe clock: %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(qmp->pipediv2_clk);
+	if (ret) {
+		dev_err(qmp->dev, "failed to enable pipediv2 clock: %d\n", ret);
+		goto err_disable_pipe_clk;
+	}
+
+	return 0;
+
+err_disable_pipe_clk:
+	clk_disable_unprepare(qmp->pipe_clk);
+
+	return ret;
+}
+
+static void pipe_clk_disable(struct qmp_pcie *qmp)
+{
+	clk_disable_unprepare(qmp->pipediv2_clk);
+	clk_disable_unprepare(qmp->pipe_clk);
+}
+
 static int qmp_pcie_power_on(struct phy *phy)
 {
 	struct qmp_pcie *qmp = phy_get_drvdata(phy);
@@ -1923,11 +1955,9 @@  static int qmp_pcie_power_on(struct phy *phy)
 	qmp_pcie_init_registers(qmp, &cfg->tables);
 	qmp_pcie_init_registers(qmp, mode_tables);
 
-	ret = clk_prepare_enable(qmp->pipe_clk);
-	if (ret) {
-		dev_err(qmp->dev, "pipe_clk enable failed err=%d\n", ret);
+	ret = pipe_clk_enable(qmp);
+	if (ret)
 		return ret;
-	}
 
 	/* Pull PHY out of reset state */
 	qphy_clrbits(pcs, cfg->regs[QPHY_SW_RESET], SW_RESET);
@@ -1950,7 +1980,7 @@  static int qmp_pcie_power_on(struct phy *phy)
 	return 0;
 
 err_disable_pipe_clk:
-	clk_disable_unprepare(qmp->pipe_clk);
+	pipe_clk_disable(qmp);
 
 	return ret;
 }
@@ -1960,7 +1990,7 @@  static int qmp_pcie_power_off(struct phy *phy)
 	struct qmp_pcie *qmp = phy_get_drvdata(phy);
 	const struct qmp_phy_cfg *cfg = qmp->cfg;
 
-	clk_disable_unprepare(qmp->pipe_clk);
+	pipe_clk_disable(qmp);
 
 	/* PHY reset */
 	qphy_setbits(qmp->pcs, cfg->regs[QPHY_SW_RESET], SW_RESET);