Subject: [RFC][PATCH 1/2] ARM: OMAP4: clock: Add device tree support for AUXCLKs

From: [email-masked] (Tony Lindgren)
Date: Wed, 3 Apr 2013 16:42:43 -0700

Hi,

* Roger Quadros <[email-masked]> [130319 07:31]:
> Register a device tree clock provider for AUX clocks
> on the OMAP4 SoC. Also provide the binding information.
> 
> Signed-off-by: Roger Quadros <[email-masked]>
> ---
>  .../devicetree/bindings/clock/omap4-clock.txt      |   32 ++++++++++++++++++
>  arch/arm/boot/dts/omap4.dtsi                       |    5 +++
>  arch/arm/mach-omap2/board-generic.c                |    2 +-
>  arch/arm/mach-omap2/cclock44xx_data.c              |   35 ++++++++++++++++++++
>  arch/arm/mach-omap2/clock44xx.h                    |    1 +
>  arch/arm/mach-omap2/common.h                       |    9 +++++
>  arch/arm/mach-omap2/io.c                           |    6 +++
>  7 files changed, 89 insertions(+), 1 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/clock/omap4-clock.txt
> 
...

> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/omap4-clock.txt

Is this really specific to omap4 and auxclk only?

Shouldn't it be just omap-clock.txt?

> --- a/arch/arm/mach-omap2/cclock44xx_data.c
> +++ b/arch/arm/mach-omap2/cclock44xx_data.c
> @@ -27,6 +27,7 @@
>  #include <linux/clk-private.h>
>  #include <linux/clkdev.h>
>  #include <linux/io.h>
> +#include <linux/of.h>
>  
>  #include "soc.h"
>  #include "iomap.h"
> @@ -1663,6 +1664,40 @@ static struct omap_clk omap44xx_clks[] = {
>  	CLK(NULL,	"cpufreq_ck",	&dpll_mpu_ck,	CK_443X),
>  };
>  
> +static struct clk *scrm_clks[] = {
> +	&auxclk0_ck,
> +	&auxclk1_ck,
> +	&auxclk2_ck,
> +	&auxclk3_ck,
> +	&auxclk4_ck,
> +	&auxclk5_ck,
> +};

Hmm I don't like the idea of specifying the auxclk both in the
cclock44xx_data.c and in DT..

> +static struct clk_onecell_data scrm_data;
> +
> +#ifdef CONFIG_OF
> +int __init omap4_clk_init_dt(void)
> +{
> +	struct device_node *np;
> +
> +	np = of_find_compatible_node(NULL, NULL, "ti,omap4-scrm");
> +	if (np) {
> +		scrm_data.clks = scrm_clks;
> +		scrm_data.clk_num = ARRAY_SIZE(scrm_clks);
> +		of_clk_add_provider(np, of_clk_src_onecell_get,	&scrm_data);
> +	}
> +
> +	return 0;
> +}
> +
> +#else
> +
> +int __init omap4_clk_init_dt(void)
> +{
> +	return 0;
> +}
> +#endif /* CONFIG_OF */
> +
>  int __init omap4xxx_clk_init(void)
>  {
>  	u32 cpu_clkflg;

.. and I'm not too keen on adding driver specific stuff to this file.

How about just add a minimal drivers/clk/omap/clk-xyz.c that takes
the configuration from DT and is based on the binding we already have in
Documentation/devicetree/bindings/clock/clock-bindings.txt?

Then as we add new bindings there we can drop them from current
cclock44xx_data.c, no? That is after omap4 is DT only..

Regards,

Tony