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

[Tero Kristo <t-kristo@ti.com>]

On 10/31/2013 06:05 PM, Nishanth Menon wrote:
> 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 ?

Hmm yea that would work.

>> +}
>> +
>> +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 ?

Same.

>
> and ofcourse error handling for regmap ops..

What do you propose to do in error case? Panic, WARN() or just printk?

>
>> +}
>> +
>> +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.

Ok, I can try to do that for next. :P

>
>> +{
>> +	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?

You get zero offset.

I can add a check for this though.

>
>> +	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;
>>
>
>