Re: [PATCH v9 01/27] clk: davinci: pll: allow dev == NULL

[David Lechner]

On 05/01/2018 08:27 AM, Sekhar Nori wrote:
> On Friday 27 April 2018 05:47 AM, David Lechner wrote:
> > This modifies the TI DaVinci PLL clock driver to allow for the case
> > when dev == NULL. On some (most) SoCs that use this driver, the PLL
> > clock needs to be registered during early boot because it is used
> > for clocksource/clockevent and there will be no platform device available.
> >
> > Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx>
>
> > diff --git a/drivers/clk/davinci/pll.c b/drivers/clk/davinci/pll.c
> > index 23a24c944f1d..7c4d808b8fdb 100644
> > --- a/drivers/clk/davinci/pll.c
> > +++ b/drivers/clk/davinci/pll.c
> > @@ -111,6 +111,31 @@ struct davinci_pll_clk {
> >   #define to_davinci_pll_clk(_hw) \
> >   	container_of((_hw), struct davinci_pll_clk, hw)
> >   
> > +static inline void *_devm_kzalloc(struct device *dev, size_t size, gfp_t flags)
> > +{
> > +	if (dev)
> > +		return devm_kzalloc(dev, size, flags);
> > +
> > +	return kzalloc(size, flags);
>
> I would shift to using kzalloc() only. The utility of devm_kzalloc() is
> gone if you cannot always rely on it since you have to handle the free
> for the other case. Same thing for other devres APIs below.

I omitted the usual unwinding on failure since if a non-platform-device
clock fails to init, then Linux won't boot anyway. I left the devm stuff
in there since there is one case where this driver is still used as a
platform device, thinking that there could be an EPROBE_DEFER. However
I think all uses of these inline functions are after the last possible
EPROBE_DEFER, so doing as you suggest is probably just fine.


> > +}
> > +
> > +static inline void *_devm_kmalloc_array(struct device *dev, size_t n,
> > +					size_t size, gfp_t flags)
> > +{
> > +	if (dev)
> > +		return devm_kmalloc_array(dev, n, size, flags);
> > +
> > +	return kmalloc_array(n, size, flags);
> > +}
> > +
> > +static inline struct clk *_devm_clk_register(struct device *dev, struct clk_hw *hw)
> > +{
> > +	if (dev)
> > +		return devm_clk_register(dev, hw);
> > +
> > +	return clk_register(NULL, hw);
> > +}
> > +
>
>
> > diff --git a/drivers/clk/davinci/pll.h b/drivers/clk/davinci/pll.h
> > index b1b6fb23f972..92a0978a7d29 100644
> > --- a/drivers/clk/davinci/pll.h
> > +++ b/drivers/clk/davinci/pll.h
> > @@ -11,6 +11,7 @@
> >   #include <linux/bitops.h>
> >   #include <linux/clk-provider.h>
> >   #include <linux/of.h>
> > +#include <linux/regmap.h>
> >   #include <linux/types.h>
> >   
> >   #define PLL_HAS_CLKMODE			BIT(0) /* PLL has PLLCTL[CLKMODE] */
> > @@ -94,7 +95,8 @@ struct davinci_pll_obsclk_info {
> >   struct clk *davinci_pll_clk_register(struct device *dev,
> >   				     const struct davinci_pll_clk_info *info,
> >   				     const char *parent_name,
> > -				     void __iomem *base);
> > +				     void __iomem *base,
> > +				     struct regmap *cfgchip);
> >   struct clk *davinci_pll_auxclk_register(struct device *dev,
> >   					const char *name,
> >   					void __iomem *base);
> > @@ -110,32 +112,33 @@ davinci_pll_sysclk_register(struct device *dev,
> >   			    const struct davinci_pll_sysclk_info *info,
> >   			    void __iomem *base);
> >   
> > -int of_davinci_pll_init(struct device *dev,
> > +int of_davinci_pll_init(struct device *dev, struct device_node *node,
> >   			const struct davinci_pll_clk_info *info,
> >   			const struct davinci_pll_obsclk_info *obsclk_info,
> >   			const struct davinci_pll_sysclk_info **div_info,
> >   			u8 max_sysclk_id,
> > -			void __iomem *base);
> > +			void __iomem *base,
> > +			struct regmap *cfgchip);
> >   
> >   /* Platform-specific callbacks */
> >   
> > -int da830_pll_init(struct device *dev, void __iomem *base);
> > +int da830_pll_init(struct device *dev, void __iomem *base, struct regmap *cfgchip);
> >   
> > -int da850_pll0_init(struct device *dev, void __iomem *base);
> > -int da850_pll1_init(struct device *dev, void __iomem *base);
> > -int of_da850_pll0_init(struct device *dev, void __iomem *base);
> > -int of_da850_pll1_init(struct device *dev, void __iomem *base);
> > +int da850_pll0_init(struct device *dev, void __iomem *base, struct regmap *cfgchip);
>
> Having this declared both here and in include/linux/clk/davinci.h is
> strange. Can we include that file directly where its needed?

Sure thing. There are a number of duplicates that can be eliminated.

> > diff --git a/include/linux/clk/davinci.h b/include/linux/clk/davinci.h
> > new file mode 100644
> > index 000000000000..1298cca509ac
> > --- /dev/null
> > +++ b/include/linux/clk/davinci.h
> > @@ -0,0 +1,24 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Clock driver for TI Davinci PSC controllers
>
> PSC/PLL controllers.
>
> Thanks,
> Sekhar