Re: [PATCH v4 01/15] PCI: imx6: Simplify clock handling by using bulk_clk_*() function

[Frank Li]

On Sun, Dec 17, 2023 at 10:36:55PM +0530, Manivannan Sadhasivam wrote:
> On Sun, Dec 17, 2023 at 12:11:56AM -0500, Frank Li wrote:
> > Refactors the clock handling logic in the imx6 PCI driver by adding
> > clk_names[] define in drvdata . Simplifies the code and makes it more
> > maintainable, as future additions of SOC support will only require
> > straightforward changes.
> > 
> 
> Commit description should be in imperative mood as per
> Documentation/process/submitting-patches.rst:
> 
> "Describe your changes in imperative mood, e.g. "make xyzzy do frotz"
> instead of "[This patch] makes xyzzy do frotz" or "[I] changed xyzzy
> to do frotz", as if you are giving orders to the codebase to change
> its behaviour."

How about: 

Refactors the clock handling logic. Adds clk_names[] define in drvdata.
Using clk_bulk*() api simplifies the code.

> 
> > Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
> > ---
> > 
> > Notes:
> >     Change from v3 to v4
> >     - using clk_bulk_*() API
> >     Change from v1 to v3
> >     - none
> > 
> >  drivers/pci/controller/dwc/pci-imx6.c | 128 ++++++++------------------
> >  1 file changed, 38 insertions(+), 90 deletions(-)
> > 
> > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> > index 74703362aeec7..2086214345e9a 100644
> > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> 
> [...]
> 
> >  static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
> > @@ -1305,32 +1265,19 @@ static int imx6_pcie_probe(struct platform_device *pdev)
> >  		return imx6_pcie->reset_gpio;
> >  	}
> >  
> > -	/* Fetch clocks */
> > -	imx6_pcie->pcie_bus = devm_clk_get(dev, "pcie_bus");
> > -	if (IS_ERR(imx6_pcie->pcie_bus))
> > -		return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie_bus),
> > -				     "pcie_bus clock source missing or invalid\n");
> > +	while (imx6_pcie->drvdata->clk_names[imx6_pcie->clks_cnt]) {
> > +		int i = imx6_pcie->clks_cnt;
> >  
> > -	imx6_pcie->pcie = devm_clk_get(dev, "pcie");
> > -	if (IS_ERR(imx6_pcie->pcie))
> > -		return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie),
> > -				     "pcie clock source missing or invalid\n");
> > +		imx6_pcie->clks[i].id = imx6_pcie->drvdata->clk_names[i];
> > +		imx6_pcie->clks_cnt++;
> 
> You can just initialize clks_cnt in drv_data with sizeof() of clk_names.

sizeof will return pre allocated clk_names size, for here, it should be 6.
Not initilized string cnt.

or you have to duplicate two line 
	clk_names = {"clk1", "clk2", ...},
	clks_cnt = ARRAY_SIZE({"clk1", "clk2", ...},


Anyway, it need copy to clks[i].id, count here is simple.

Frank


> 
> > +	}
> > +
> > +	/* Fetch clocks */
> > +	ret = devm_clk_bulk_get(dev, imx6_pcie->clks_cnt, imx6_pcie->clks);
> > +	if (ret)
> > +		return ret;
> >  
> >  	switch (imx6_pcie->drvdata->variant) {
> > -	case IMX6SX:
> > -		imx6_pcie->pcie_inbound_axi = devm_clk_get(dev,
> > -							   "pcie_inbound_axi");
> > -		if (IS_ERR(imx6_pcie->pcie_inbound_axi))
> > -			return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie_inbound_axi),
> > -					     "pcie_inbound_axi clock missing or invalid\n");
> > -		break;
> > -	case IMX8MQ:
> > -	case IMX8MQ_EP:
> > -		imx6_pcie->pcie_aux = devm_clk_get(dev, "pcie_aux");
> > -		if (IS_ERR(imx6_pcie->pcie_aux))
> > -			return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie_aux),
> > -					     "pcie_aux clock source missing or invalid\n");
> > -		fallthrough;
> >  	case IMX7D:
> >  		if (dbi_base->start == IMX8MQ_PCIE2_BASE_ADDR)
> >  			imx6_pcie->controller_id = 1;
> > @@ -1353,10 +1300,6 @@ static int imx6_pcie_probe(struct platform_device *pdev)
> >  	case IMX8MM_EP:
> >  	case IMX8MP:
> >  	case IMX8MP_EP:
> > -		imx6_pcie->pcie_aux = devm_clk_get(dev, "pcie_aux");
> > -		if (IS_ERR(imx6_pcie->pcie_aux))
> > -			return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie_aux),
> > -					     "pcie_aux clock source missing or invalid\n");
> >  		imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev,
> >  									 "apps");
> >  		if (IS_ERR(imx6_pcie->apps_reset))
> > @@ -1372,14 +1315,6 @@ static int imx6_pcie_probe(struct platform_device *pdev)
> >  	default:
> >  		break;
> >  	}
> > -	/* Don't fetch the pcie_phy clock, if it has abstract PHY driver */
> > -	if (imx6_pcie->phy == NULL) {
> > -		imx6_pcie->pcie_phy = devm_clk_get(dev, "pcie_phy");
> > -		if (IS_ERR(imx6_pcie->pcie_phy))
> > -			return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie_phy),
> > -					     "pcie_phy clock source missing or invalid\n");
> > -	}
> > -
> >  
> >  	/* Grab turnoff reset */
> >  	imx6_pcie->turnoff_reset = devm_reset_control_get_optional_exclusive(dev, "turnoff");
> > @@ -1470,6 +1405,9 @@ static void imx6_pcie_shutdown(struct platform_device *pdev)
> >  	imx6_pcie_assert_core_reset(imx6_pcie);
> >  }
> >  
> > +#define IMX6_CLKS_COMMON "pcie_bus", "pcie"
> > +#define IMX6_CLKS_NO_PHYDRV IMX6_CLKS_COMMON, "pcie_phy"
> > +
> 
> Just use the clock names directly instead of definitions. It makes the code more
> readable.
> 
> Rest LGTM!
> 
> - Mani
> 
> -- 
> மணிவண்ணன் சதாசிவம்