Re: [PATCHv9 07/43] CLK: TI: add autoidle support

[Nishanth Menon <nm@ti.com>]

On 10/25/2013 10:57 AM, Tero Kristo wrote:
> TI clk driver now routes some of the basic clocks through own
> registration routine to allow autoidle support. This routine just
> checks a couple of device node properties and adds autoidle support
> if required, and just passes the registration forward to basic clocks.
> 
> Signed-off-by: Tero Kristo <t-kristo@ti.com>
> ---
>  arch/arm/mach-omap2/clock.c |    6 +++
>  drivers/clk/ti/Makefile     |    2 +-
>  drivers/clk/ti/autoidle.c   |  109 +++++++++++++++++++++++++++++++++++++++++++
>  include/linux/clk/ti.h      |    9 ++++
>  4 files changed, 125 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/clk/ti/autoidle.c
> 
> diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c
> index 0c38ca9..223f432b 100644
> --- a/arch/arm/mach-omap2/clock.c
> +++ b/arch/arm/mach-omap2/clock.c
> @@ -520,6 +520,9 @@ int omap2_clk_enable_autoidle_all(void)
>  	list_for_each_entry(c, &clk_hw_omap_clocks, node)
>  		if (c->ops && c->ops->allow_idle)
>  			c->ops->allow_idle(c);
> +
> +	of_ti_clk_allow_autoidle_all();
> +
>  	return 0;
>  }
>  
> @@ -539,6 +542,9 @@ int omap2_clk_disable_autoidle_all(void)
>  	list_for_each_entry(c, &clk_hw_omap_clocks, node)
>  		if (c->ops && c->ops->deny_idle)
>  			c->ops->deny_idle(c);
> +
> +	of_ti_clk_deny_autoidle_all();
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/clk/ti/Makefile b/drivers/clk/ti/Makefile
> index 05af5d8..533efb4 100644
> --- a/drivers/clk/ti/Makefile
> +++ b/drivers/clk/ti/Makefile
> @@ -1,3 +1,3 @@
>  ifneq ($(CONFIG_OF),)
> -obj-y					+= clk.o dpll.o
> +obj-y					+= clk.o dpll.o autoidle.o
>  endif
> diff --git a/drivers/clk/ti/autoidle.c b/drivers/clk/ti/autoidle.c
> new file mode 100644
> index 0000000..efa2a3e
> --- /dev/null
> +++ b/drivers/clk/ti/autoidle.c
> @@ -0,0 +1,109 @@
> +/*
> + * TI clock autoidle support
> + *
> + * Copyright (C) 2013 Texas Instruments, Inc.
> + *
> + * Tero Kristo <t-kristo@ti.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
> + * kind, whether express or implied; without even the implied warranty
> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/slab.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/clk/ti.h>
> +
> +struct clk_ti_autoidle {
> +	u32			reg;
> +	struct regmap		*regmap;
> +	u8			shift;
> +	u8			flags;
> +	const char		*name;
> +	struct list_head	node;
> +};
> +
> +#define AUTOIDLE_LOW		0x1
> +
> +static LIST_HEAD(autoidle_clks);
> +
> +static void ti_allow_autoidle(struct clk_ti_autoidle *clk)
> +{
> +	u32 val;
> +
> +	regmap_read(clk->regmap, clk->reg, &val);
> +
> +	if (clk->flags & AUTOIDLE_LOW)
> +		val &= ~(1 << clk->shift);
> +	else
> +		val |= (1 << clk->shift);
> +
> +	regmap_write(clk->regmap, clk->reg, val);
regmap_update_bits ?
> +}
> +
> +static void ti_deny_autoidle(struct clk_ti_autoidle *clk)
> +{
> +	u32 val;
> +
> +	regmap_read(clk->regmap, clk->reg, &val);
> +
> +	if (clk->flags & AUTOIDLE_LOW)
> +		val |= (1 << clk->shift);
> +	else
> +		val &= ~(1 << clk->shift);
> +
> +	regmap_write(clk->regmap, clk->reg, val);
regmap_update_bits ?

and ofcourse error handling for regmap ops..

> +}
> +
> +void of_ti_clk_allow_autoidle_all(void)
> +{
> +	struct clk_ti_autoidle *c;
> +
> +	list_for_each_entry(c, &autoidle_clks, node)
> +		ti_allow_autoidle(c);
> +}
> +
> +void of_ti_clk_deny_autoidle_all(void)
> +{
> +	struct clk_ti_autoidle *c;
> +
> +	list_for_each_entry(c, &autoidle_clks, node)
> +		ti_deny_autoidle(c);
> +}
> +
> +int __init of_ti_autoidle_setup(struct device_node *node,
> +				struct regmap *regmap)

will be nice if you could kernel-doc all public functions at the very
least.

> +{
> +	u32 shift;
> +	struct clk_ti_autoidle *clk;
> +
> +	if (of_property_read_u32(node, "ti,autoidle-shift", &shift))
> +		return 0;
> +
> +	clk = kzalloc(sizeof(*clk), GFP_KERNEL);
> +
> +	if (!clk) {
> +		pr_err("%s: kzalloc failed\n", __func__);
> +		return -ENOMEM;
> +	}
> +
> +	clk->shift = shift;
> +	clk->name = node->name;
> +	of_property_read_u32(node, "reg", &clk->reg);

dt binding?
what happens if someone forgets this?

> +	clk->regmap = regmap;
> +
> +	if (of_property_read_bool(node, "ti,invert-autoidle-bit"))
> +		clk->flags |= AUTOIDLE_LOW;
> +
> +	list_add(&clk->node, &autoidle_clks);
> +
> +	return 0;
> +}
> diff --git a/include/linux/clk/ti.h b/include/linux/clk/ti.h
> index 7ab02fa..e45005c 100644
> --- a/include/linux/clk/ti.h
> +++ b/include/linux/clk/ti.h
> @@ -178,6 +178,15 @@ int omap3_dpll4_set_rate(struct clk_hw *clk, unsigned long rate,
>  
>  void ti_dt_clocks_register(struct ti_dt_clk *oclks);
>  void ti_dt_clk_init_provider(struct device_node *np, struct regmap *regmap);
> +int of_ti_autoidle_setup(struct device_node *node, struct regmap *regmap);
> +
> +#ifdef CONFIG_OF
> +void of_ti_clk_allow_autoidle_all(void);
> +void of_ti_clk_deny_autoidle_all(void);
> +#else
> +static inline void of_ti_clk_allow_autoidle_all(void) { }
> +static inline void of_ti_clk_deny_autoidle_all(void) { }
> +#endif
>  
>  extern const struct clk_hw_omap_ops clkhwops_omap3_dpll;
>  extern const struct clk_hw_omap_ops clkhwops_omap4_dpllmx;
> 


-- 
Regards,
Nishanth Menon