diff mbox

[PATCHv4,03/33] CLK: OMAP4: Add DPLL clock support

Message ID 1374564028-11352-4-git-send-email-t-kristo@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Tero Kristo July 23, 2013, 7:19 a.m. UTC
The OMAP clock driver now supports DPLL clock type. This patch also
adds support for DT DPLL nodes.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
---
 drivers/clk/omap/Makefile |    2 +-
 drivers/clk/omap/clk.c    |    1 +
 drivers/clk/omap/dpll.c   |  295 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 297 insertions(+), 1 deletion(-)
 create mode 100644 drivers/clk/omap/dpll.c

Comments

Nishanth Menon July 30, 2013, 4:23 p.m. UTC | #1
This patch probably was submitted in the wrong sequence - fails build 
and few other issues below.

On 07/23/2013 02:19 AM, Tero Kristo wrote:
> The OMAP clock driver now supports DPLL clock type. This patch also
> adds support for DT DPLL nodes.

Then why is $subject specific to OMAP4? is that because of 
of_omap4_dpll_setup?

>
> Signed-off-by: Tero Kristo <t-kristo@ti.com>
> ---
>   drivers/clk/omap/Makefile |    2 +-
>   drivers/clk/omap/clk.c    |    1 +
>   drivers/clk/omap/dpll.c   |  295 +++++++++++++++++++++++++++++++++++++++++++++

Device Tree Binding documentation?

>   3 files changed, 297 insertions(+), 1 deletion(-)
>   create mode 100644 drivers/clk/omap/dpll.c
>
> diff --git a/drivers/clk/omap/Makefile b/drivers/clk/omap/Makefile
> index 8195931..4cad480 100644
> --- a/drivers/clk/omap/Makefile
> +++ b/drivers/clk/omap/Makefile
> @@ -1 +1 @@
> -obj-y					+= clk.o
> +obj-y					+= clk.o dpll.o
> diff --git a/drivers/clk/omap/clk.c b/drivers/clk/omap/clk.c
> index 4bf1929..1dafdaa 100644
> --- a/drivers/clk/omap/clk.c
> +++ b/drivers/clk/omap/clk.c
> @@ -28,6 +28,7 @@ static const struct of_device_id clk_match[] = {
>   		.data = of_fixed_factor_clk_setup, },
>   	{.compatible = "divider-clock", .data = of_divider_clk_setup, },
>   	{.compatible = "gate-clock", .data = of_gate_clk_setup, },
> +	{.compatible = "ti,omap4-dpll-clock", .data = of_omap4_dpll_setup, },
>   	{},
>   };
you would not need this if you did just of_clk_init(NULL); ?

Further, at this patch, build fails with:
drivers/clk/omap/clk.c:31:55: error: undefined identifier 
'of_omap4_dpll_setup'
drivers/clk/omap/clk.c:31:48: error: ‘of_omap4_dpll_setup’ undeclared 
here (not in a function)

which makes sense since we did not export the function.	
>
> diff --git a/drivers/clk/omap/dpll.c b/drivers/clk/omap/dpll.c
> new file mode 100644
> index 0000000..66e82be
> --- /dev/null
> +++ b/drivers/clk/omap/dpll.c
> @@ -0,0 +1,295 @@
> +/*
> + * OMAP DPLL clock 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/module.h>
> +#include <linux/slab.h>
> +#include <linux/io.h>
> +#include <linux/err.h>
> +#include <linux/string.h>
> +#include <linux/log2.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
after a quick check, are all these required?

> +#include <linux/clk/omap.h>

why?

> +
> +static const struct clk_ops dpll_m4xen_ck_ops = {
> +	.enable		= &omap3_noncore_dpll_enable,
> +	.disable	= &omap3_noncore_dpll_disable,
> +	.recalc_rate	= &omap4_dpll_regm4xen_recalc,
> +	.round_rate	= &omap4_dpll_regm4xen_round_rate,
> +	.set_rate	= &omap3_noncore_dpll_set_rate,
> +	.get_parent	= &omap2_init_dpll_parent,
> +};
> +
> +static const struct clk_ops dpll_core_ck_ops = {
> +	.recalc_rate	= &omap3_dpll_recalc,
> +	.get_parent	= &omap2_init_dpll_parent,
> +};
> +
> +static const struct clk_ops dpll_ck_ops = {
> +	.enable		= &omap3_noncore_dpll_enable,
> +	.disable	= &omap3_noncore_dpll_disable,
> +	.recalc_rate	= &omap3_dpll_recalc,
> +	.round_rate	= &omap2_dpll_round_rate,
> +	.set_rate	= &omap3_noncore_dpll_set_rate,
> +	.get_parent	= &omap2_init_dpll_parent,
> +	.init		= &omap2_init_clk_clkdm,
> +};
> +
> +static const struct clk_ops dpll_x2_ck_ops = {
> +	.recalc_rate	= &omap3_clkoutx2_recalc,
> +};

none of these are defined at this stage of the patch, generates a huge 
build error for dpll.c
http://pastebin.com/GJucv1A5
> +
> +struct clk *omap_clk_register_dpll(struct device *dev, const char *name,
> +		const char **parent_names, int num_parents, unsigned long flags,
> +		struct dpll_data *dpll_data, const char *clkdm_name,
> +		const struct clk_ops *ops)

why should this be public?

> +{
> +	struct clk *clk;
> +	struct clk_init_data init;

init = { 0 };  just to future proof?

> +	struct clk_hw_omap *clk_hw;

does not exist yet in generic header?

I am assuming you do not do parameter check as you expect clk_register 
to do the same?

> +
> +	/* allocate the divider */
> +	clk_hw = kzalloc(sizeof(struct clk_hw_omap), GFP_KERNEL);
checkpatch complained:
CHECK: Prefer kzalloc(sizeof(*clk_hw)...) over kzalloc(sizeof(struct 
clk_hw_omap)...)

or given we have dev, devm_kzalloc?
> +	if (!clk_hw) {
> +		pr_err("%s: could not allocate clk_hw_omap\n", __func__);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	clk_hw->dpll_data = dpll_data;
> +	clk_hw->ops = &clkhwops_omap3_dpll;
> +	clk_hw->clkdm_name = clkdm_name;
> +	clk_hw->hw.init = &init;
> +
> +	init.name = name;
> +	init.ops = ops;
> +	init.flags = flags;
> +	init.parent_names = parent_names;
> +	init.num_parents = num_parents;
> +
> +	/* register the clock */
> +	clk = clk_register(dev, &clk_hw->hw);
> +
> +	if (IS_ERR(clk))
> +		kfree(clk_hw);
> +	else
> +		omap2_init_clk_hw_omap_clocks(clk);
what if init fails? and it is in mach-omap2 at this point in time?

> +
> +	return clk;
> +}
> +
> +struct clk *omap_clk_register_dpll_x2(struct device *dev, const char *name,
> +		const char *parent_name, void __iomem *reg,
> +		const struct clk_ops *ops)

same question here as well

> +{
> +	struct clk *clk;
> +	struct clk_init_data init;
> +	struct clk_hw_omap *clk_hw;
> +
> +	if (!parent_name) {
> +		pr_err("%s: dpll_x2 must have parent\n", __func__);
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	clk_hw = kzalloc(sizeof(struct clk_hw_omap), GFP_KERNEL);
checkpatch complained:
CHECK: Prefer kzalloc(sizeof(*clk_hw)...) over kzalloc(sizeof(struct 
clk_hw_omap)...)

or devm_kzalloc?

> +	if (!clk_hw) {
> +		pr_err("%s: could not allocate clk_hw_omap\n", __func__);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	clk_hw->ops = &clkhwops_omap4_dpllmx;
> +	clk_hw->clksel_reg = reg;
> +	clk_hw->hw.init = &init;
> +
> +	init.name = name;
> +	init.ops = ops;
> +	init.parent_names = &parent_name;
> +	init.num_parents = 1;
> +
> +	/* register the clock */
> +	clk = clk_register(dev, &clk_hw->hw);
> +
> +	if (IS_ERR(clk))
> +		kfree(clk_hw);
> +	else
> +		omap2_init_clk_hw_omap_clocks(clk);
> +
> +	return clk;
> +}
this vaguely sounds like a replica of omap_clk_register_dpll with 
num_parents and clk_hw->ops different. why not merge the two?

> +
> +#ifdef CONFIG_OF

why not build the entire thing *iff* CONFIG_OF (Makefile/Kconfig dep)? 
that way, we can drop this #ifdef stuff from drivers that dont need to 
have dual support.

> +
> +/**
> + * of_omap_dpll_setup() - Setup function for OMAP DPLL clocks

node and ops not documented.

> + */
> +static void __init of_omap_dpll_setup(struct device_node *node,
> +					const struct clk_ops *ops)
> +{
> +	struct clk *clk;
> +	const char *clk_name = node->name;
> +	int num_parents;
> +	const char **parent_names;
> +	const char *clkdm_name = NULL;
> +	struct of_phandle_args clkspec;
> +	u8 dpll_flags = 0;
> +	struct dpll_data *dd;
> +	u32 idlest_mask = 0x1;
> +	u32 enable_mask = 0x7;
> +	u32 autoidle_mask = 0x7;
> +	u32 mult_mask = 0x7ff << 8;
> +	u32 div1_mask = 0x7f;
> +	u32 max_multiplier = 2047;
> +	u32 max_divider = 128;
> +	u32 min_divider = 1;
> +	int i;
> +
> +	dd = kzalloc(sizeof(struct dpll_data), GFP_KERNEL);
kzalloc sizeof(*dd) ?

> +	if (!dd) {
> +		pr_err("%s: could not allocate dpll_data\n", __func__);
> +		return;
> +	}
> +
> +	of_property_read_string(node, "clock-output-names", &clk_name);
> +
> +	num_parents = of_clk_get_parent_count(node);
> +	if (num_parents < 1) {
> +		pr_err("%s: omap dpll %s must have parent(s)\n",
> +			__func__, node->name);

checkpatch complained:
CHECK: Alignment should match open parenthesis
#212: FILE: drivers/clk/omap/dpll.c:171:
After applying the patch, I think you should make __func__ aligned with 
" and not %

> +		goto cleanup;
> +	}
> +
> +	parent_names = kzalloc(sizeof(char *) * num_parents, GFP_KERNEL);
> +
> +	for (i = 0; i < num_parents; i++)
> +		parent_names[i] = of_clk_get_parent_name(node, i);
> +
> +	of_property_read_u32(node, "ti,idlest-mask", &idlest_mask);
> +
> +	of_property_read_u32(node, "ti,enable-mask", &enable_mask);
> +
> +	of_property_read_u32(node, "ti,autoidle-mask", &autoidle_mask);

are these going to be different? or can we catch with compatible flag?

> +
> +	clkspec.np = of_parse_phandle(node, "ti,clk-ref", 0);
> +	dd->clk_ref = of_clk_get_from_provider(&clkspec);
> +	if (!dd->clk_ref) {
> +		pr_err("%s: ti,clk-ref for %s not found\n", __func__,
> +			clk_name);

CHECK: Alignment should match open parenthesis
#231: FILE: drivers/clk/omap/dpll.c:190:
similar issue here.

> +		goto cleanup;
> +	}
> +
> +	clkspec.np = of_parse_phandle(node, "ti,clk-bypass", 0);
> +	dd->clk_bypass = of_clk_get_from_provider(&clkspec);
> +	if (!dd->clk_bypass) {
> +		pr_err("%s: ti,clk-bypass for %s not found\n", __func__,
> +			clk_name);

here as well

> +		goto cleanup;
> +	}
> +
> +	of_property_read_string(node, "ti,clkdm-name", &clkdm_name);
> +
> +	dd->control_reg = of_iomap(node, 0);
> +	dd->idlest_reg = of_iomap(node, 1);
> +	dd->autoidle_reg = of_iomap(node, 2);
> +	dd->mult_div1_reg = of_iomap(node, 3);

if dts has errors, should we not verify mandatory parameters?

> +
> +	dd->idlest_mask = idlest_mask;
> +	dd->enable_mask = enable_mask;
> +	dd->autoidle_mask = autoidle_mask;
> +
> +	dd->modes = 0xa0;

what is 0xa0?

> +
> +	if (of_property_read_bool(node, "ti,dpll-j-type")) {
> +		dd->sddiv_mask = 0xff000000;
> +		mult_mask = 0xfff << 8;
> +		div1_mask = 0xff;
> +		max_multiplier = 4095;
> +		max_divider = 256;
> +	}
> +
> +	if (of_property_read_bool(node, "ti,dpll-regm4xen")) {
I think we need bindings to understand this better.

> +		dd->m4xen_mask = 0x800;
> +		dd->lpmode_mask = 1 << 10;
> +	}
> +
> +	dd->mult_mask = mult_mask;
> +	dd->div1_mask = div1_mask;
> +	dd->max_multiplier = max_multiplier;
> +	dd->max_divider = max_divider;
> +	dd->min_divider = min_divider;
> +
> +	clk = omap_clk_register_dpll(NULL, clk_name, parent_names,
> +				num_parents, dpll_flags, dd,
> +				clkdm_name, ops);
> +
> +	if (!IS_ERR(clk))
> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
error check?
> +	return;
> +
> +cleanup:

kfree(parent_names) ?

> +	kfree(dd);
> +	return;
> +}
> +
> +static void __init of_omap_dpll_x2_setup(struct device_node *node)
> +{
> +	struct clk *clk;
> +	const char *clk_name = node->name;
> +	void __iomem *reg;
> +	const char *parent_name;
> +
> +	of_property_read_string(node, "clock-output-names", &clk_name);
> +
> +	parent_name = of_clk_get_parent_name(node, 0);
> +
> +	reg = of_iomap(node, 0);

if dts has errors, should we not verify mandatory parameters?

> +
> +	clk = omap_clk_register_dpll_x2(NULL, clk_name, parent_name,
> +				reg, &dpll_x2_ck_ops);
> +
> +	if (!IS_ERR(clk))
> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
error check?

gentle request - in this setup function we dont see a return of error 
value (which makes sense), but more importantly - log saying that node 
was not setup

> +}
> +
> +__init void of_omap3_dpll_setup(struct device_node *node)

^^ void __init? further, you could make this static.

> +{
> +	/* XXX: to be done */
> +}
> +EXPORT_SYMBOL_GPL(of_omap3_dpll_setup);

you can drop the export if you use of_clk_init(NULL);

> +CLK_OF_DECLARE(omap3_dpll_clock, "ti,omap3-dpll-clock", of_omap3_dpll_setup);
> +
> +__init void of_omap4_dpll_setup(struct device_node *node)

^^ void __init? further, you could make this static.

> +{
> +	const struct clk_ops *ops;
> +
> +	ops = &dpll_ck_ops;
> +
> +	if (of_property_read_bool(node, "ti,dpll-regm4xen"))
> +		ops = &dpll_m4xen_ck_ops;
> +
> +	if (of_property_read_bool(node, "ti,dpll-core"))
> +		ops = &dpll_core_ck_ops;
> +
> +	if (of_property_read_bool(node, "ti,dpll-clk-x2")) {
> +		of_omap_dpll_x2_setup(node);
> +		return;
> +	}
> +
> +	of_omap_dpll_setup(node, ops);
> +}
> +EXPORT_SYMBOL_GPL(of_omap4_dpll_setup);

you can drop the export if you use of_clk_init(NULL);

> +CLK_OF_DECLARE(omap4_dpll_clock, "ti,omap4-dpll-clock", of_omap4_dpll_setup);
> +#endif
>
Tero Kristo July 31, 2013, 9:46 a.m. UTC | #2
On 07/30/2013 07:23 PM, Nishanth Menon wrote:
> This patch probably was submitted in the wrong sequence - fails build
> and few other issues below.

Yeah, I'll double check the build sequence for these.

>
> On 07/23/2013 02:19 AM, Tero Kristo wrote:
>> The OMAP clock driver now supports DPLL clock type. This patch also
>> adds support for DT DPLL nodes.
>
> Then why is $subject specific to OMAP4? is that because of
> of_omap4_dpll_setup?

The driver only supports omap4 dpll type at this point, omap3 dplls 
require some modifications on top of this, and are provided later in the 
series.

>
>>
>> Signed-off-by: Tero Kristo <t-kristo@ti.com>
>> ---
>>   drivers/clk/omap/Makefile |    2 +-
>>   drivers/clk/omap/clk.c    |    1 +
>>   drivers/clk/omap/dpll.c   |  295
>> +++++++++++++++++++++++++++++++++++++++++++++
>
> Device Tree Binding documentation?

Didn't bother writing those yet as I haven't received too much feedback 
whether this approach is acceptable or not.

>
>>   3 files changed, 297 insertions(+), 1 deletion(-)
>>   create mode 100644 drivers/clk/omap/dpll.c
>>
>> diff --git a/drivers/clk/omap/Makefile b/drivers/clk/omap/Makefile
>> index 8195931..4cad480 100644
>> --- a/drivers/clk/omap/Makefile
>> +++ b/drivers/clk/omap/Makefile
>> @@ -1 +1 @@
>> -obj-y                    += clk.o
>> +obj-y                    += clk.o dpll.o
>> diff --git a/drivers/clk/omap/clk.c b/drivers/clk/omap/clk.c
>> index 4bf1929..1dafdaa 100644
>> --- a/drivers/clk/omap/clk.c
>> +++ b/drivers/clk/omap/clk.c
>> @@ -28,6 +28,7 @@ static const struct of_device_id clk_match[] = {
>>           .data = of_fixed_factor_clk_setup, },
>>       {.compatible = "divider-clock", .data = of_divider_clk_setup, },
>>       {.compatible = "gate-clock", .data = of_gate_clk_setup, },
>> +    {.compatible = "ti,omap4-dpll-clock", .data =
>> of_omap4_dpll_setup, },
>>       {},
>>   };
> you would not need this if you did just of_clk_init(NULL); ?

Why not? And I think we still need to do this.

>
> Further, at this patch, build fails with:
> drivers/clk/omap/clk.c:31:55: error: undefined identifier
> 'of_omap4_dpll_setup'
> drivers/clk/omap/clk.c:31:48: error: ‘of_omap4_dpll_setup’ undeclared
> here (not in a function)
>
> which makes sense since we did not export the function.

Yea seems like wrong ordering of patches, sorry about that. >.<

>>
>> diff --git a/drivers/clk/omap/dpll.c b/drivers/clk/omap/dpll.c
>> new file mode 100644
>> index 0000000..66e82be
>> --- /dev/null
>> +++ b/drivers/clk/omap/dpll.c
>> @@ -0,0 +1,295 @@
>> +/*
>> + * OMAP DPLL clock 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/module.h>
>> +#include <linux/slab.h>
>> +#include <linux/io.h>
>> +#include <linux/err.h>
>> +#include <linux/string.h>
>> +#include <linux/log2.h>
>> +#include <linux/of.h>
>> +#include <linux/of_address.h>
> after a quick check, are all these required?

Seems like some might not be needed, I'll double check this.

>
>> +#include <linux/clk/omap.h>
>
> why?

Need dpll_data definition for example.

>
>> +
>> +static const struct clk_ops dpll_m4xen_ck_ops = {
>> +    .enable        = &omap3_noncore_dpll_enable,
>> +    .disable    = &omap3_noncore_dpll_disable,
>> +    .recalc_rate    = &omap4_dpll_regm4xen_recalc,
>> +    .round_rate    = &omap4_dpll_regm4xen_round_rate,
>> +    .set_rate    = &omap3_noncore_dpll_set_rate,
>> +    .get_parent    = &omap2_init_dpll_parent,
>> +};
>> +
>> +static const struct clk_ops dpll_core_ck_ops = {
>> +    .recalc_rate    = &omap3_dpll_recalc,
>> +    .get_parent    = &omap2_init_dpll_parent,
>> +};
>> +
>> +static const struct clk_ops dpll_ck_ops = {
>> +    .enable        = &omap3_noncore_dpll_enable,
>> +    .disable    = &omap3_noncore_dpll_disable,
>> +    .recalc_rate    = &omap3_dpll_recalc,
>> +    .round_rate    = &omap2_dpll_round_rate,
>> +    .set_rate    = &omap3_noncore_dpll_set_rate,
>> +    .get_parent    = &omap2_init_dpll_parent,
>> +    .init        = &omap2_init_clk_clkdm,
>> +};
>> +
>> +static const struct clk_ops dpll_x2_ck_ops = {
>> +    .recalc_rate    = &omap3_clkoutx2_recalc,
>> +};
>
> none of these are defined at this stage of the patch, generates a huge
> build error for dpll.c
> http://pastebin.com/GJucv1A5

Yea, wrong ordering, linux/clk/omap.h is not up to date. I'll fix this 
and rest of the similar issues.

>> +
>> +struct clk *omap_clk_register_dpll(struct device *dev, const char *name,
>> +        const char **parent_names, int num_parents, unsigned long flags,
>> +        struct dpll_data *dpll_data, const char *clkdm_name,
>> +        const struct clk_ops *ops)
>
> why should this be public?

Currently does not need to be, but someone could in theory build up 
cclockXxxx_data.c file and use these calls from there. Kind of legacy 
support, see some of the basic clk types. I guess I can add static to 
this, and remove some of the params along.

>
>> +{
>> +    struct clk *clk;
>> +    struct clk_init_data init;
>
> init = { 0 };  just to future proof?

Good idea, i'll add this.

>
>> +    struct clk_hw_omap *clk_hw;
>
> does not exist yet in generic header?

Yea.

>
> I am assuming you do not do parameter check as you expect clk_register
> to do the same?

True, so I'll change the above function to static.

>
>> +
>> +    /* allocate the divider */
>> +    clk_hw = kzalloc(sizeof(struct clk_hw_omap), GFP_KERNEL);
> checkpatch complained:
> CHECK: Prefer kzalloc(sizeof(*clk_hw)...) over kzalloc(sizeof(struct
> clk_hw_omap)...)

Hmm, I didn't get this with checkpatch. Some special option/version you 
use? I still see both types of sizeof used in the kernel.

>
> or given we have dev, devm_kzalloc?

Actually we don't have dev, check how this is called from below.

>> +    if (!clk_hw) {
>> +        pr_err("%s: could not allocate clk_hw_omap\n", __func__);
>> +        return ERR_PTR(-ENOMEM);
>> +    }
>> +
>> +    clk_hw->dpll_data = dpll_data;
>> +    clk_hw->ops = &clkhwops_omap3_dpll;
>> +    clk_hw->clkdm_name = clkdm_name;
>> +    clk_hw->hw.init = &init;
>> +
>> +    init.name = name;
>> +    init.ops = ops;
>> +    init.flags = flags;
>> +    init.parent_names = parent_names;
>> +    init.num_parents = num_parents;
>> +
>> +    /* register the clock */
>> +    clk = clk_register(dev, &clk_hw->hw);
>> +
>> +    if (IS_ERR(clk))
>> +        kfree(clk_hw);
>> +    else
>> +        omap2_init_clk_hw_omap_clocks(clk);
> what if init fails? and it is in mach-omap2 at this point in time?

Yea, this just calls the autoidle init part under mach-omap2.

>
>> +
>> +    return clk;
>> +}
>> +
>> +struct clk *omap_clk_register_dpll_x2(struct device *dev, const char
>> *name,
>> +        const char *parent_name, void __iomem *reg,
>> +        const struct clk_ops *ops)
>
> same question here as well

Yea, can change to static I think.

>
>> +{
>> +    struct clk *clk;
>> +    struct clk_init_data init;
>> +    struct clk_hw_omap *clk_hw;
>> +
>> +    if (!parent_name) {
>> +        pr_err("%s: dpll_x2 must have parent\n", __func__);
>> +        return ERR_PTR(-EINVAL);
>> +    }
>> +
>> +    clk_hw = kzalloc(sizeof(struct clk_hw_omap), GFP_KERNEL);
> checkpatch complained:
> CHECK: Prefer kzalloc(sizeof(*clk_hw)...) over kzalloc(sizeof(struct
> clk_hw_omap)...)
>
> or devm_kzalloc?

Same as above.

>
>> +    if (!clk_hw) {
>> +        pr_err("%s: could not allocate clk_hw_omap\n", __func__);
>> +        return ERR_PTR(-ENOMEM);
>> +    }
>> +
>> +    clk_hw->ops = &clkhwops_omap4_dpllmx;
>> +    clk_hw->clksel_reg = reg;
>> +    clk_hw->hw.init = &init;
>> +
>> +    init.name = name;
>> +    init.ops = ops;
>> +    init.parent_names = &parent_name;
>> +    init.num_parents = 1;
>> +
>> +    /* register the clock */
>> +    clk = clk_register(dev, &clk_hw->hw);
>> +
>> +    if (IS_ERR(clk))
>> +        kfree(clk_hw);
>> +    else
>> +        omap2_init_clk_hw_omap_clocks(clk);
>> +
>> +    return clk;
>> +}
> this vaguely sounds like a replica of omap_clk_register_dpll with
> num_parents and clk_hw->ops different. why not merge the two?

Some of the params are different but yes, I'll see if I can merge the two.

>
>> +
>> +#ifdef CONFIG_OF
>
> why not build the entire thing *iff* CONFIG_OF (Makefile/Kconfig dep)?
> that way, we can drop this #ifdef stuff from drivers that dont need to
> have dual support.

Yea, I guess I can do this.

>
>> +
>> +/**
>> + * of_omap_dpll_setup() - Setup function for OMAP DPLL clocks
>
> node and ops not documented.

I'll add some beef here.

>
>> + */
>> +static void __init of_omap_dpll_setup(struct device_node *node,
>> +                    const struct clk_ops *ops)
>> +{
>> +    struct clk *clk;
>> +    const char *clk_name = node->name;
>> +    int num_parents;
>> +    const char **parent_names;
>> +    const char *clkdm_name = NULL;
>> +    struct of_phandle_args clkspec;
>> +    u8 dpll_flags = 0;
>> +    struct dpll_data *dd;
>> +    u32 idlest_mask = 0x1;
>> +    u32 enable_mask = 0x7;
>> +    u32 autoidle_mask = 0x7;
>> +    u32 mult_mask = 0x7ff << 8;
>> +    u32 div1_mask = 0x7f;
>> +    u32 max_multiplier = 2047;
>> +    u32 max_divider = 128;
>> +    u32 min_divider = 1;
>> +    int i;
>> +
>> +    dd = kzalloc(sizeof(struct dpll_data), GFP_KERNEL);
> kzalloc sizeof(*dd) ?

See above.

>
>> +    if (!dd) {
>> +        pr_err("%s: could not allocate dpll_data\n", __func__);
>> +        return;
>> +    }
>> +
>> +    of_property_read_string(node, "clock-output-names", &clk_name);
>> +
>> +    num_parents = of_clk_get_parent_count(node);
>> +    if (num_parents < 1) {
>> +        pr_err("%s: omap dpll %s must have parent(s)\n",
>> +            __func__, node->name);
>
> checkpatch complained:
> CHECK: Alignment should match open parenthesis
> #212: FILE: drivers/clk/omap/dpll.c:171:
> After applying the patch, I think you should make __func__ aligned with
> " and not %

Again, what version of checkpatch you use? Or what flags?

>
>> +        goto cleanup;
>> +    }
>> +
>> +    parent_names = kzalloc(sizeof(char *) * num_parents, GFP_KERNEL);
>> +
>> +    for (i = 0; i < num_parents; i++)
>> +        parent_names[i] = of_clk_get_parent_name(node, i);
>> +
>> +    of_property_read_u32(node, "ti,idlest-mask", &idlest_mask);
>> +
>> +    of_property_read_u32(node, "ti,enable-mask", &enable_mask);
>> +
>> +    of_property_read_u32(node, "ti,autoidle-mask", &autoidle_mask);
>
> are these going to be different? or can we catch with compatible flag?

For example, omap3 dpll4:

dpll4_ck: dpll4_ck@48004d00 {
         ti,autoidle-mask = <0x38>;
         ti,idlest-mask = <0x2>;
         ti,enable-mask = <0x70000>;
};

It seems that currently we can catch all cases with the 
ti,dpll-peripheral flag. I'll modify the code accordingly.


>
>> +
>> +    clkspec.np = of_parse_phandle(node, "ti,clk-ref", 0);
>> +    dd->clk_ref = of_clk_get_from_provider(&clkspec);
>> +    if (!dd->clk_ref) {
>> +        pr_err("%s: ti,clk-ref for %s not found\n", __func__,
>> +            clk_name);
>
> CHECK: Alignment should match open parenthesis
> #231: FILE: drivers/clk/omap/dpll.c:190:
> similar issue here.
>
>> +        goto cleanup;
>> +    }
>> +
>> +    clkspec.np = of_parse_phandle(node, "ti,clk-bypass", 0);
>> +    dd->clk_bypass = of_clk_get_from_provider(&clkspec);
>> +    if (!dd->clk_bypass) {
>> +        pr_err("%s: ti,clk-bypass for %s not found\n", __func__,
>> +            clk_name);
>
> here as well
>
>> +        goto cleanup;
>> +    }
>> +
>> +    of_property_read_string(node, "ti,clkdm-name", &clkdm_name);
>> +
>> +    dd->control_reg = of_iomap(node, 0);
>> +    dd->idlest_reg = of_iomap(node, 1);
>> +    dd->autoidle_reg = of_iomap(node, 2);
>> +    dd->mult_div1_reg = of_iomap(node, 3);
>
> if dts has errors, should we not verify mandatory parameters?
>
>> +
>> +    dd->idlest_mask = idlest_mask;
>> +    dd->enable_mask = enable_mask;
>> +    dd->autoidle_mask = autoidle_mask;
>> +
>> +    dd->modes = 0xa0;
>
> what is 0xa0?

Magic mode. :) I'll copy paste a macro for this.

>
>> +
>> +    if (of_property_read_bool(node, "ti,dpll-j-type")) {
>> +        dd->sddiv_mask = 0xff000000;
>> +        mult_mask = 0xfff << 8;
>> +        div1_mask = 0xff;
>> +        max_multiplier = 4095;
>> +        max_divider = 256;
>> +    }
>> +
>> +    if (of_property_read_bool(node, "ti,dpll-regm4xen")) {
> I think we need bindings to understand this better.

Or documentation you mean?

>
>> +        dd->m4xen_mask = 0x800;
>> +        dd->lpmode_mask = 1 << 10;
>> +    }
>> +
>> +    dd->mult_mask = mult_mask;
>> +    dd->div1_mask = div1_mask;
>> +    dd->max_multiplier = max_multiplier;
>> +    dd->max_divider = max_divider;
>> +    dd->min_divider = min_divider;
>> +
>> +    clk = omap_clk_register_dpll(NULL, clk_name, parent_names,
>> +                num_parents, dpll_flags, dd,
>> +                clkdm_name, ops);
>> +
>> +    if (!IS_ERR(clk))
>> +        of_clk_add_provider(node, of_clk_src_simple_get, clk);
> error check?

This is not done with other drivers either. Would require clk_unregister 
use to cleanup the above register call which is currently unavailable. I 
could add an error trace for this though.

>> +    return;
>> +
>> +cleanup:
>
> kfree(parent_names) ?

Hmm yea.

>
>> +    kfree(dd);
>> +    return;
>> +}
>> +
>> +static void __init of_omap_dpll_x2_setup(struct device_node *node)
>> +{
>> +    struct clk *clk;
>> +    const char *clk_name = node->name;
>> +    void __iomem *reg;
>> +    const char *parent_name;
>> +
>> +    of_property_read_string(node, "clock-output-names", &clk_name);
>> +
>> +    parent_name = of_clk_get_parent_name(node, 0);
>> +
>> +    reg = of_iomap(node, 0);
>
> if dts has errors, should we not verify mandatory parameters?

You mean checking the validity of this pointer? It seems of_iomap does 
something strange when it fails, e.g. when passed a 0x0 from DT. You can 
see what I do in a later patch for adding am335x support for DPLLs.

>
>> +
>> +    clk = omap_clk_register_dpll_x2(NULL, clk_name, parent_name,
>> +                reg, &dpll_x2_ck_ops);
>> +
>> +    if (!IS_ERR(clk))
>> +        of_clk_add_provider(node, of_clk_src_simple_get, clk);
> error check?
>
> gentle request - in this setup function we dont see a return of error
> value (which makes sense), but more importantly - log saying that node
> was not setup

Yea, I can add error prints.

>
>> +}
>> +
>> +__init void of_omap3_dpll_setup(struct device_node *node)
>
> ^^ void __init? further, you could make this static.

Ok.

>
>> +{
>> +    /* XXX: to be done */
>> +}
>> +EXPORT_SYMBOL_GPL(of_omap3_dpll_setup);
>
> you can drop the export if you use of_clk_init(NULL);

Same comment as earlier.

>
>> +CLK_OF_DECLARE(omap3_dpll_clock, "ti,omap3-dpll-clock",
>> of_omap3_dpll_setup);
>> +
>> +__init void of_omap4_dpll_setup(struct device_node *node)
>
> ^^ void __init? further, you could make this static.

Ok.

>
>> +{
>> +    const struct clk_ops *ops;
>> +
>> +    ops = &dpll_ck_ops;
>> +
>> +    if (of_property_read_bool(node, "ti,dpll-regm4xen"))
>> +        ops = &dpll_m4xen_ck_ops;
>> +
>> +    if (of_property_read_bool(node, "ti,dpll-core"))
>> +        ops = &dpll_core_ck_ops;
>> +
>> +    if (of_property_read_bool(node, "ti,dpll-clk-x2")) {
>> +        of_omap_dpll_x2_setup(node);
>> +        return;
>> +    }
>> +
>> +    of_omap_dpll_setup(node, ops);
>> +}
>> +EXPORT_SYMBOL_GPL(of_omap4_dpll_setup);
>
> you can drop the export if you use of_clk_init(NULL);

Hmm no?

Actually dug this further, I think the init setup is slightly wrong at 
the moment, we should not do CLK_OF_DECLARE at all within the omap 
specific clock drivers, but instead just use the match table from clk.c. 
I'll change it like so.

>
>> +CLK_OF_DECLARE(omap4_dpll_clock, "ti,omap4-dpll-clock",
>> of_omap4_dpll_setup);

So, for example this should be removed. We don't want to support this 
clock type on non-omap platforms just to avoid problems.

>> +#endif
>>
Rajendra Nayak Aug. 1, 2013, 8:29 a.m. UTC | #3
Tero,

On Tuesday 23 July 2013 12:49 PM, Tero Kristo wrote:
> +	dd->control_reg = of_iomap(node, 0);
> +	dd->idlest_reg = of_iomap(node, 1);
> +	dd->autoidle_reg = of_iomap(node, 2);
> +	dd->mult_div1_reg = of_iomap(node, 3);
> +
[]...
> +	reg = of_iomap(node, 0);

Doing an of_iomap() for every single clock register seems like an overkill
and might have performance penalties at boot.

regards,
Rajendra
Nishanth Menon Aug. 1, 2013, 2 p.m. UTC | #4
On 07/31/2013 04:46 AM, Tero Kristo wrote:
> On 07/30/2013 07:23 PM, Nishanth Menon wrote:
>> This patch probably was submitted in the wrong sequence - fails build
>> and few other issues below.
>
> Yeah, I'll double check the build sequence for these.
>
>>
>> On 07/23/2013 02:19 AM, Tero Kristo wrote:
>>> The OMAP clock driver now supports DPLL clock type. This patch also
>>> adds support for DT DPLL nodes.
>>
>> Then why is $subject specific to OMAP4? is that because of
>> of_omap4_dpll_setup?
>
> The driver only supports omap4 dpll type at this point, omap3 dplls
> require some modifications on top of this, and are provided later in the
> series.

ok.

>
>>
>>>
>>> Signed-off-by: Tero Kristo <t-kristo@ti.com>
>>> ---
>>>   drivers/clk/omap/Makefile |    2 +-
>>>   drivers/clk/omap/clk.c    |    1 +
>>>   drivers/clk/omap/dpll.c   |  295
>>> +++++++++++++++++++++++++++++++++++++++++++++
>>
>> Device Tree Binding documentation?
>
> Didn't bother writing those yet as I haven't received too much feedback
> whether this approach is acceptable or not.

Documentation helps simplify the understanding of expected usage - this 
is useful to review approach as well :)

>>> diff --git a/drivers/clk/omap/clk.c b/drivers/clk/omap/clk.c
>>> index 4bf1929..1dafdaa 100644
>>> --- a/drivers/clk/omap/clk.c
>>> +++ b/drivers/clk/omap/clk.c
>>> @@ -28,6 +28,7 @@ static const struct of_device_id clk_match[] = {
>>>           .data = of_fixed_factor_clk_setup, },
>>>       {.compatible = "divider-clock", .data = of_divider_clk_setup, },
>>>       {.compatible = "gate-clock", .data = of_gate_clk_setup, },
>>> +    {.compatible = "ti,omap4-dpll-clock", .data =
>>> of_omap4_dpll_setup, },
>>>       {},
>>>   };
>> you would not need this if you did just of_clk_init(NULL); ?
>
> Why not? And I think we still need to do this.

CLK_OF_DECLARE will take care of having all required clks registered 
of_clk_init(NULL); will pick up from that list.

that will remove all extra exports, and make clk.c redundant.
[...]

>
>>
>>> +#include <linux/clk/omap.h>
>>
>> why?
>
> Need dpll_data definition for example.
OK - without the ordering of patches, it was not obvious. structures aside,

We should move the functions to this file instead and empty out 
mach-omap2 gradually, omap_dpll.h should be exported and used by 
mach-omap2, rather than the other way around.

>>> +
>>> +struct clk *omap_clk_register_dpll(struct device *dev, const char
>>> *name,
>>> +        const char **parent_names, int num_parents, unsigned long
>>> flags,
>>> +        struct dpll_data *dpll_data, const char *clkdm_name,
>>> +        const struct clk_ops *ops)
>>
>> why should this be public?
>
> Currently does not need to be, but someone could in theory build up
> cclockXxxx_data.c file and use these calls from there. Kind of legacy
> support, see some of the basic clk types. I guess I can add static to
> this, and remove some of the params along.
>

thanks. we should keep unneeded stuff in static unless a specific 
provable need really arises.

>>
>> I am assuming you do not do parameter check as you expect clk_register
>> to do the same?
>
> True, so I'll change the above function to static.
>
>>
>>> +
>>> +    /* allocate the divider */
>>> +    clk_hw = kzalloc(sizeof(struct clk_hw_omap), GFP_KERNEL);
>> checkpatch complained:
>> CHECK: Prefer kzalloc(sizeof(*clk_hw)...) over kzalloc(sizeof(struct
>> clk_hw_omap)...)
>
> Hmm, I didn't get this with checkpatch. Some special option/version you
> use? I still see both types of sizeof used in the kernel.
use checkpatch with --strict option

>
>>
>> or given we have dev, devm_kzalloc?
>
> Actually we don't have dev, check how this is called from below.

ok.

>
>>> +    if (!clk_hw) {
>>> +        pr_err("%s: could not allocate clk_hw_omap\n", __func__);
>>> +        return ERR_PTR(-ENOMEM);
>>> +    }
>>> +
>>> +    clk_hw->dpll_data = dpll_data;
>>> +    clk_hw->ops = &clkhwops_omap3_dpll;
>>> +    clk_hw->clkdm_name = clkdm_name;
>>> +    clk_hw->hw.init = &init;
>>> +
>>> +    init.name = name;
>>> +    init.ops = ops;
>>> +    init.flags = flags;
>>> +    init.parent_names = parent_names;
>>> +    init.num_parents = num_parents;
>>> +
>>> +    /* register the clock */
>>> +    clk = clk_register(dev, &clk_hw->hw);
>>> +
>>> +    if (IS_ERR(clk))
>>> +        kfree(clk_hw);
>>> +    else
>>> +        omap2_init_clk_hw_omap_clocks(clk);
>> what if init fails? and it is in mach-omap2 at this point in time?
>
> Yea, this just calls the autoidle init part under mach-omap2.

we should make this independent of mach-omap2. calls should be made to 
here if needed from mach-omap2 instead of the other way around. OR the 
required code should be moved over here.

>
>>
>>> +
>>> +    return clk;
>>> +}
>>
<snip>
>>
>>> +
>>> +    if (of_property_read_bool(node, "ti,dpll-j-type")) {
>>> +        dd->sddiv_mask = 0xff000000;
>>> +        mult_mask = 0xfff << 8;
>>> +        div1_mask = 0xff;
>>> +        max_multiplier = 4095;
>>> +        max_divider = 256;
>>> +    }
>>> +
>>> +    if (of_property_read_bool(node, "ti,dpll-regm4xen")) {
>> I think we need bindings to understand this better.
>
> Or documentation you mean?

yes. Documentation/devicetree/bindings/....

>
>>
>>> +        dd->m4xen_mask = 0x800;
>>> +        dd->lpmode_mask = 1 << 10;
>>> +    }
>>> +
>>> +    dd->mult_mask = mult_mask;
>>> +    dd->div1_mask = div1_mask;
>>> +    dd->max_multiplier = max_multiplier;
>>> +    dd->max_divider = max_divider;
>>> +    dd->min_divider = min_divider;
>>> +
>>> +    clk = omap_clk_register_dpll(NULL, clk_name, parent_names,
>>> +                num_parents, dpll_flags, dd,
>>> +                clkdm_name, ops);
>>> +
>>> +    if (!IS_ERR(clk))
>>> +        of_clk_add_provider(node, of_clk_src_simple_get, clk);
>> error check?
>
> This is not done with other drivers either. Would require clk_unregister
> use to cleanup the above register call which is currently unavailable. I
> could add an error trace for this though.

you can definitely ensure this driver is clean :)

>>
>>> +    kfree(dd);
>>> +    return;
>>> +}
>>> +
>>> +static void __init of_omap_dpll_x2_setup(struct device_node *node)
>>> +{
>>> +    struct clk *clk;
>>> +    const char *clk_name = node->name;
>>> +    void __iomem *reg;
>>> +    const char *parent_name;
>>> +
>>> +    of_property_read_string(node, "clock-output-names", &clk_name);
>>> +
>>> +    parent_name = of_clk_get_parent_name(node, 0);
>>> +
>>> +    reg = of_iomap(node, 0);
>>
>> if dts has errors, should we not verify mandatory parameters?
>
> You mean checking the validity of this pointer? It seems of_iomap does
> something strange when it fails, e.g. when passed a 0x0 from DT. You can
> see what I do in a later patch for adding am335x support for DPLLs.

in general, helping dts writers know of invalid/out of range parameters 
with a log message helps ensure those are fixed either on development or 
at some point - it aids debug instead of others having to scratch heads 
wondering what happened.

if mandatory parameters are verifable at setup and decided as bad, 
refusing to register is good idea especially with logs, they tend to get 
fixed rather faster - than an error that pops up when a specific DPLL is 
used at a later point in time.

just my 2 cents.
[..]

>>> +}
>>> +EXPORT_SYMBOL_GPL(of_omap4_dpll_setup);
>>
>> you can drop the export if you use of_clk_init(NULL);
>
> Hmm no?
>
> Actually dug this further, I think the init setup is slightly wrong at
> the moment, we should not do CLK_OF_DECLARE at all within the omap
> specific clock drivers, but instead just use the match table from clk.c.
> I'll change it like so.
>
>>
>>> +CLK_OF_DECLARE(omap4_dpll_clock, "ti,omap4-dpll-clock",
>>> of_omap4_dpll_setup);
>
> So, for example this should be removed. We don't want to support this
> clock type on non-omap platforms just to avoid problems.

As discussed offline, doing the other way around and doing what all 
other platforms do (which is CLK_OF_DECLARE) is a better idea to ensure 
standard APIs are carried forward and not spin off OMAP as a "special 
platform" - at least I dont seem to see any good reasoning for it yet.
Tero Kristo Aug. 1, 2013, 3:08 p.m. UTC | #5
On 08/01/2013 05:00 PM, Nishanth Menon wrote:
> On 07/31/2013 04:46 AM, Tero Kristo wrote:
>> On 07/30/2013 07:23 PM, Nishanth Menon wrote:
>>> This patch probably was submitted in the wrong sequence - fails build
>>> and few other issues below.
>>
>> Yeah, I'll double check the build sequence for these.
>>
>>>
>>> On 07/23/2013 02:19 AM, Tero Kristo wrote:
>>>> The OMAP clock driver now supports DPLL clock type. This patch also
>>>> adds support for DT DPLL nodes.
>>>
>>> Then why is $subject specific to OMAP4? is that because of
>>> of_omap4_dpll_setup?
>>
>> The driver only supports omap4 dpll type at this point, omap3 dplls
>> require some modifications on top of this, and are provided later in the
>> series.
>
> ok.
>
>>
>>>
>>>>
>>>> Signed-off-by: Tero Kristo <t-kristo@ti.com>
>>>> ---
>>>>   drivers/clk/omap/Makefile |    2 +-
>>>>   drivers/clk/omap/clk.c    |    1 +
>>>>   drivers/clk/omap/dpll.c   |  295
>>>> +++++++++++++++++++++++++++++++++++++++++++++
>>>
>>> Device Tree Binding documentation?
>>
>> Didn't bother writing those yet as I haven't received too much feedback
>> whether this approach is acceptable or not.
>
> Documentation helps simplify the understanding of expected usage - this
> is useful to review approach as well :)

True, I'll try adding docs for next rev.

>
>>>> diff --git a/drivers/clk/omap/clk.c b/drivers/clk/omap/clk.c
>>>> index 4bf1929..1dafdaa 100644
>>>> --- a/drivers/clk/omap/clk.c
>>>> +++ b/drivers/clk/omap/clk.c
>>>> @@ -28,6 +28,7 @@ static const struct of_device_id clk_match[] = {
>>>>           .data = of_fixed_factor_clk_setup, },
>>>>       {.compatible = "divider-clock", .data = of_divider_clk_setup, },
>>>>       {.compatible = "gate-clock", .data = of_gate_clk_setup, },
>>>> +    {.compatible = "ti,omap4-dpll-clock", .data =
>>>> of_omap4_dpll_setup, },
>>>>       {},
>>>>   };
>>> you would not need this if you did just of_clk_init(NULL); ?
>>
>> Why not? And I think we still need to do this.
>
> CLK_OF_DECLARE will take care of having all required clks registered
> of_clk_init(NULL); will pick up from that list.
>
> that will remove all extra exports, and make clk.c redundant.
> [...]

Yep, as agreed on previous patch.

>
>>
>>>
>>>> +#include <linux/clk/omap.h>
>>>
>>> why?
>>
>> Need dpll_data definition for example.
> OK - without the ordering of patches, it was not obvious. structures aside,
>
> We should move the functions to this file instead and empty out
> mach-omap2 gradually, omap_dpll.h should be exported and used by
> mach-omap2, rather than the other way around.

Yeah, the clock stuff should evolve and move here. I just need to start 
from somewhere.

>
>>>> +
>>>> +struct clk *omap_clk_register_dpll(struct device *dev, const char
>>>> *name,
>>>> +        const char **parent_names, int num_parents, unsigned long
>>>> flags,
>>>> +        struct dpll_data *dpll_data, const char *clkdm_name,
>>>> +        const struct clk_ops *ops)
>>>
>>> why should this be public?
>>
>> Currently does not need to be, but someone could in theory build up
>> cclockXxxx_data.c file and use these calls from there. Kind of legacy
>> support, see some of the basic clk types. I guess I can add static to
>> this, and remove some of the params along.
>>
>
> thanks. we should keep unneeded stuff in static unless a specific
> provable need really arises.
>
>>>
>>> I am assuming you do not do parameter check as you expect clk_register
>>> to do the same?
>>
>> True, so I'll change the above function to static.
>>
>>>
>>>> +
>>>> +    /* allocate the divider */
>>>> +    clk_hw = kzalloc(sizeof(struct clk_hw_omap), GFP_KERNEL);
>>> checkpatch complained:
>>> CHECK: Prefer kzalloc(sizeof(*clk_hw)...) over kzalloc(sizeof(struct
>>> clk_hw_omap)...)
>>
>> Hmm, I didn't get this with checkpatch. Some special option/version you
>> use? I still see both types of sizeof used in the kernel.
> use checkpatch with --strict option

Okay.

>
>>
>>>
>>> or given we have dev, devm_kzalloc?
>>
>> Actually we don't have dev, check how this is called from below.
>
> ok.
>
>>
>>>> +    if (!clk_hw) {
>>>> +        pr_err("%s: could not allocate clk_hw_omap\n", __func__);
>>>> +        return ERR_PTR(-ENOMEM);
>>>> +    }
>>>> +
>>>> +    clk_hw->dpll_data = dpll_data;
>>>> +    clk_hw->ops = &clkhwops_omap3_dpll;
>>>> +    clk_hw->clkdm_name = clkdm_name;
>>>> +    clk_hw->hw.init = &init;
>>>> +
>>>> +    init.name = name;
>>>> +    init.ops = ops;
>>>> +    init.flags = flags;
>>>> +    init.parent_names = parent_names;
>>>> +    init.num_parents = num_parents;
>>>> +
>>>> +    /* register the clock */
>>>> +    clk = clk_register(dev, &clk_hw->hw);
>>>> +
>>>> +    if (IS_ERR(clk))
>>>> +        kfree(clk_hw);
>>>> +    else
>>>> +        omap2_init_clk_hw_omap_clocks(clk);
>>> what if init fails? and it is in mach-omap2 at this point in time?
>>
>> Yea, this just calls the autoidle init part under mach-omap2.
>
> we should make this independent of mach-omap2. calls should be made to
> here if needed from mach-omap2 instead of the other way around. OR the
> required code should be moved over here.

Same comment as above, I did not want to move the allow / deny idle 
portion of every possible clock under drivers/clk/omap yet. This is on 
the evolution path for this driver.

>
>>
>>>
>>>> +
>>>> +    return clk;
>>>> +}
>>>
> <snip>
>>>
>>>> +
>>>> +    if (of_property_read_bool(node, "ti,dpll-j-type")) {
>>>> +        dd->sddiv_mask = 0xff000000;
>>>> +        mult_mask = 0xfff << 8;
>>>> +        div1_mask = 0xff;
>>>> +        max_multiplier = 4095;
>>>> +        max_divider = 256;
>>>> +    }
>>>> +
>>>> +    if (of_property_read_bool(node, "ti,dpll-regm4xen")) {
>>> I think we need bindings to understand this better.
>>
>> Or documentation you mean?
>
> yes. Documentation/devicetree/bindings/....
>
>>
>>>
>>>> +        dd->m4xen_mask = 0x800;
>>>> +        dd->lpmode_mask = 1 << 10;
>>>> +    }
>>>> +
>>>> +    dd->mult_mask = mult_mask;
>>>> +    dd->div1_mask = div1_mask;
>>>> +    dd->max_multiplier = max_multiplier;
>>>> +    dd->max_divider = max_divider;
>>>> +    dd->min_divider = min_divider;
>>>> +
>>>> +    clk = omap_clk_register_dpll(NULL, clk_name, parent_names,
>>>> +                num_parents, dpll_flags, dd,
>>>> +                clkdm_name, ops);
>>>> +
>>>> +    if (!IS_ERR(clk))
>>>> +        of_clk_add_provider(node, of_clk_src_simple_get, clk);
>>> error check?
>>
>> This is not done with other drivers either. Would require clk_unregister
>> use to cleanup the above register call which is currently unavailable. I
>> could add an error trace for this though.
>
> you can definitely ensure this driver is clean :)

Not really, as the clk_unregister does not work, so the implementation 
for this can't be exactly clean yet. I don't know if we want to 
unregister any clocks anyway if this would fail...

>
>>>
>>>> +    kfree(dd);
>>>> +    return;
>>>> +}
>>>> +
>>>> +static void __init of_omap_dpll_x2_setup(struct device_node *node)
>>>> +{
>>>> +    struct clk *clk;
>>>> +    const char *clk_name = node->name;
>>>> +    void __iomem *reg;
>>>> +    const char *parent_name;
>>>> +
>>>> +    of_property_read_string(node, "clock-output-names", &clk_name);
>>>> +
>>>> +    parent_name = of_clk_get_parent_name(node, 0);
>>>> +
>>>> +    reg = of_iomap(node, 0);
>>>
>>> if dts has errors, should we not verify mandatory parameters?
>>
>> You mean checking the validity of this pointer? It seems of_iomap does
>> something strange when it fails, e.g. when passed a 0x0 from DT. You can
>> see what I do in a later patch for adding am335x support for DPLLs.
>
> in general, helping dts writers know of invalid/out of range parameters
> with a log message helps ensure those are fixed either on development or
> at some point - it aids debug instead of others having to scratch heads
> wondering what happened.
>
> if mandatory parameters are verifable at setup and decided as bad,
> refusing to register is good idea especially with logs, they tend to get
> fixed rather faster - than an error that pops up when a specific DPLL is
> used at a later point in time.
>
> just my 2 cents.
> [..]

I'll add verification for the of_iomap calls.

>
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(of_omap4_dpll_setup);
>>>
>>> you can drop the export if you use of_clk_init(NULL);
>>
>> Hmm no?
>>
>> Actually dug this further, I think the init setup is slightly wrong at
>> the moment, we should not do CLK_OF_DECLARE at all within the omap
>> specific clock drivers, but instead just use the match table from clk.c.
>> I'll change it like so.
>>
>>>
>>>> +CLK_OF_DECLARE(omap4_dpll_clock, "ti,omap4-dpll-clock",
>>>> of_omap4_dpll_setup);
>>
>> So, for example this should be removed. We don't want to support this
>> clock type on non-omap platforms just to avoid problems.
>
> As discussed offline, doing the other way around and doing what all
> other platforms do (which is CLK_OF_DECLARE) is a better idea to ensure
> standard APIs are carried forward and not spin off OMAP as a "special
> platform" - at least I dont seem to see any good reasoning for it yet.

Yea.
Nishanth Menon Aug. 1, 2013, 3:10 p.m. UTC | #6
On 08/01/2013 03:29 AM, Rajendra Nayak wrote:
> Tero,
>
> On Tuesday 23 July 2013 12:49 PM, Tero Kristo wrote:
>> +	dd->control_reg = of_iomap(node, 0);
>> +	dd->idlest_reg = of_iomap(node, 1);
>> +	dd->autoidle_reg = of_iomap(node, 2);
>> +	dd->mult_div1_reg = of_iomap(node, 3);
>> +
> []...
>> +	reg = of_iomap(node, 0);
>
> Doing an of_iomap() for every single clock register seems like an overkill
> and might have performance penalties at boot.

the other option might be to use offset and a single allocation - but I 
think Tero should comment if this is possible or if registers on some 
SoCs are strewn all over the place
Nishanth Menon Aug. 1, 2013, 3:13 p.m. UTC | #7
On Thu, Aug 1, 2013 at 10:08 AM, Tero Kristo <t-kristo@ti.com> wrote:
>> We should move the functions to this file instead and empty out
>> mach-omap2 gradually, omap_dpll.h should be exported and used by
>> mach-omap2, rather than the other way around.
>
>
> Yeah, the clock stuff should evolve and move here. I just need to start from
> somewhere.

yep, this step is good and as part of this step, moving the used
functions from mach-omap2 to dpll.c is indeed the right step for us to
do proper cleanup.

it is a question of what we bring into drivers/clk and ensuring what
we bring in is clean as well.

Regards,
Nishanth Menon
Tero Kristo Aug. 1, 2013, 3:41 p.m. UTC | #8
On 08/01/2013 06:10 PM, Nishanth Menon wrote:
> On 08/01/2013 03:29 AM, Rajendra Nayak wrote:
>> Tero,
>>
>> On Tuesday 23 July 2013 12:49 PM, Tero Kristo wrote:
>>> +    dd->control_reg = of_iomap(node, 0);
>>> +    dd->idlest_reg = of_iomap(node, 1);
>>> +    dd->autoidle_reg = of_iomap(node, 2);
>>> +    dd->mult_div1_reg = of_iomap(node, 3);
>>> +
>> []...
>>> +    reg = of_iomap(node, 0);
>>
>> Doing an of_iomap() for every single clock register seems like an
>> overkill
>> and might have performance penalties at boot.
>
> the other option might be to use offset and a single allocation - but I
> think Tero should comment if this is possible or if registers on some
> SoCs are strewn all over the place

Well, currently the basic clock nodes also do their individual 
of_iomaps, so doing a tweak only for the OMAP DPLLs is not going to 
change the figure much.

A generic solution is needed but I think this was commented elsewhere by 
Mike to remain as future optimization (can't find the reference to this 
with a quick search though.)

-Tero
diff mbox

Patch

diff --git a/drivers/clk/omap/Makefile b/drivers/clk/omap/Makefile
index 8195931..4cad480 100644
--- a/drivers/clk/omap/Makefile
+++ b/drivers/clk/omap/Makefile
@@ -1 +1 @@ 
-obj-y					+= clk.o
+obj-y					+= clk.o dpll.o
diff --git a/drivers/clk/omap/clk.c b/drivers/clk/omap/clk.c
index 4bf1929..1dafdaa 100644
--- a/drivers/clk/omap/clk.c
+++ b/drivers/clk/omap/clk.c
@@ -28,6 +28,7 @@  static const struct of_device_id clk_match[] = {
 		.data = of_fixed_factor_clk_setup, },
 	{.compatible = "divider-clock", .data = of_divider_clk_setup, },
 	{.compatible = "gate-clock", .data = of_gate_clk_setup, },
+	{.compatible = "ti,omap4-dpll-clock", .data = of_omap4_dpll_setup, },
 	{},
 };
 
diff --git a/drivers/clk/omap/dpll.c b/drivers/clk/omap/dpll.c
new file mode 100644
index 0000000..66e82be
--- /dev/null
+++ b/drivers/clk/omap/dpll.c
@@ -0,0 +1,295 @@ 
+/*
+ * OMAP DPLL clock 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/module.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/string.h>
+#include <linux/log2.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/clk/omap.h>
+
+static const struct clk_ops dpll_m4xen_ck_ops = {
+	.enable		= &omap3_noncore_dpll_enable,
+	.disable	= &omap3_noncore_dpll_disable,
+	.recalc_rate	= &omap4_dpll_regm4xen_recalc,
+	.round_rate	= &omap4_dpll_regm4xen_round_rate,
+	.set_rate	= &omap3_noncore_dpll_set_rate,
+	.get_parent	= &omap2_init_dpll_parent,
+};
+
+static const struct clk_ops dpll_core_ck_ops = {
+	.recalc_rate	= &omap3_dpll_recalc,
+	.get_parent	= &omap2_init_dpll_parent,
+};
+
+static const struct clk_ops dpll_ck_ops = {
+	.enable		= &omap3_noncore_dpll_enable,
+	.disable	= &omap3_noncore_dpll_disable,
+	.recalc_rate	= &omap3_dpll_recalc,
+	.round_rate	= &omap2_dpll_round_rate,
+	.set_rate	= &omap3_noncore_dpll_set_rate,
+	.get_parent	= &omap2_init_dpll_parent,
+	.init		= &omap2_init_clk_clkdm,
+};
+
+static const struct clk_ops dpll_x2_ck_ops = {
+	.recalc_rate	= &omap3_clkoutx2_recalc,
+};
+
+struct clk *omap_clk_register_dpll(struct device *dev, const char *name,
+		const char **parent_names, int num_parents, unsigned long flags,
+		struct dpll_data *dpll_data, const char *clkdm_name,
+		const struct clk_ops *ops)
+{
+	struct clk *clk;
+	struct clk_init_data init;
+	struct clk_hw_omap *clk_hw;
+
+	/* allocate the divider */
+	clk_hw = kzalloc(sizeof(struct clk_hw_omap), GFP_KERNEL);
+	if (!clk_hw) {
+		pr_err("%s: could not allocate clk_hw_omap\n", __func__);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	clk_hw->dpll_data = dpll_data;
+	clk_hw->ops = &clkhwops_omap3_dpll;
+	clk_hw->clkdm_name = clkdm_name;
+	clk_hw->hw.init = &init;
+
+	init.name = name;
+	init.ops = ops;
+	init.flags = flags;
+	init.parent_names = parent_names;
+	init.num_parents = num_parents;
+
+	/* register the clock */
+	clk = clk_register(dev, &clk_hw->hw);
+
+	if (IS_ERR(clk))
+		kfree(clk_hw);
+	else
+		omap2_init_clk_hw_omap_clocks(clk);
+
+	return clk;
+}
+
+struct clk *omap_clk_register_dpll_x2(struct device *dev, const char *name,
+		const char *parent_name, void __iomem *reg,
+		const struct clk_ops *ops)
+{
+	struct clk *clk;
+	struct clk_init_data init;
+	struct clk_hw_omap *clk_hw;
+
+	if (!parent_name) {
+		pr_err("%s: dpll_x2 must have parent\n", __func__);
+		return ERR_PTR(-EINVAL);
+	}
+
+	clk_hw = kzalloc(sizeof(struct clk_hw_omap), GFP_KERNEL);
+	if (!clk_hw) {
+		pr_err("%s: could not allocate clk_hw_omap\n", __func__);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	clk_hw->ops = &clkhwops_omap4_dpllmx;
+	clk_hw->clksel_reg = reg;
+	clk_hw->hw.init = &init;
+
+	init.name = name;
+	init.ops = ops;
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+
+	/* register the clock */
+	clk = clk_register(dev, &clk_hw->hw);
+
+	if (IS_ERR(clk))
+		kfree(clk_hw);
+	else
+		omap2_init_clk_hw_omap_clocks(clk);
+
+	return clk;
+}
+
+#ifdef CONFIG_OF
+
+/**
+ * of_omap_dpll_setup() - Setup function for OMAP DPLL clocks
+ */
+static void __init of_omap_dpll_setup(struct device_node *node,
+					const struct clk_ops *ops)
+{
+	struct clk *clk;
+	const char *clk_name = node->name;
+	int num_parents;
+	const char **parent_names;
+	const char *clkdm_name = NULL;
+	struct of_phandle_args clkspec;
+	u8 dpll_flags = 0;
+	struct dpll_data *dd;
+	u32 idlest_mask = 0x1;
+	u32 enable_mask = 0x7;
+	u32 autoidle_mask = 0x7;
+	u32 mult_mask = 0x7ff << 8;
+	u32 div1_mask = 0x7f;
+	u32 max_multiplier = 2047;
+	u32 max_divider = 128;
+	u32 min_divider = 1;
+	int i;
+
+	dd = kzalloc(sizeof(struct dpll_data), GFP_KERNEL);
+	if (!dd) {
+		pr_err("%s: could not allocate dpll_data\n", __func__);
+		return;
+	}
+
+	of_property_read_string(node, "clock-output-names", &clk_name);
+
+	num_parents = of_clk_get_parent_count(node);
+	if (num_parents < 1) {
+		pr_err("%s: omap dpll %s must have parent(s)\n",
+			__func__, node->name);
+		goto cleanup;
+	}
+
+	parent_names = kzalloc(sizeof(char *) * num_parents, GFP_KERNEL);
+
+	for (i = 0; i < num_parents; i++)
+		parent_names[i] = of_clk_get_parent_name(node, i);
+
+	of_property_read_u32(node, "ti,idlest-mask", &idlest_mask);
+
+	of_property_read_u32(node, "ti,enable-mask", &enable_mask);
+
+	of_property_read_u32(node, "ti,autoidle-mask", &autoidle_mask);
+
+	clkspec.np = of_parse_phandle(node, "ti,clk-ref", 0);
+	dd->clk_ref = of_clk_get_from_provider(&clkspec);
+	if (!dd->clk_ref) {
+		pr_err("%s: ti,clk-ref for %s not found\n", __func__,
+			clk_name);
+		goto cleanup;
+	}
+
+	clkspec.np = of_parse_phandle(node, "ti,clk-bypass", 0);
+	dd->clk_bypass = of_clk_get_from_provider(&clkspec);
+	if (!dd->clk_bypass) {
+		pr_err("%s: ti,clk-bypass for %s not found\n", __func__,
+			clk_name);
+		goto cleanup;
+	}
+
+	of_property_read_string(node, "ti,clkdm-name", &clkdm_name);
+
+	dd->control_reg = of_iomap(node, 0);
+	dd->idlest_reg = of_iomap(node, 1);
+	dd->autoidle_reg = of_iomap(node, 2);
+	dd->mult_div1_reg = of_iomap(node, 3);
+
+	dd->idlest_mask = idlest_mask;
+	dd->enable_mask = enable_mask;
+	dd->autoidle_mask = autoidle_mask;
+
+	dd->modes = 0xa0;
+
+	if (of_property_read_bool(node, "ti,dpll-j-type")) {
+		dd->sddiv_mask = 0xff000000;
+		mult_mask = 0xfff << 8;
+		div1_mask = 0xff;
+		max_multiplier = 4095;
+		max_divider = 256;
+	}
+
+	if (of_property_read_bool(node, "ti,dpll-regm4xen")) {
+		dd->m4xen_mask = 0x800;
+		dd->lpmode_mask = 1 << 10;
+	}
+
+	dd->mult_mask = mult_mask;
+	dd->div1_mask = div1_mask;
+	dd->max_multiplier = max_multiplier;
+	dd->max_divider = max_divider;
+	dd->min_divider = min_divider;
+
+	clk = omap_clk_register_dpll(NULL, clk_name, parent_names,
+				num_parents, dpll_flags, dd,
+				clkdm_name, ops);
+
+	if (!IS_ERR(clk))
+		of_clk_add_provider(node, of_clk_src_simple_get, clk);
+	return;
+
+cleanup:
+	kfree(dd);
+	return;
+}
+
+static void __init of_omap_dpll_x2_setup(struct device_node *node)
+{
+	struct clk *clk;
+	const char *clk_name = node->name;
+	void __iomem *reg;
+	const char *parent_name;
+
+	of_property_read_string(node, "clock-output-names", &clk_name);
+
+	parent_name = of_clk_get_parent_name(node, 0);
+
+	reg = of_iomap(node, 0);
+
+	clk = omap_clk_register_dpll_x2(NULL, clk_name, parent_name,
+				reg, &dpll_x2_ck_ops);
+
+	if (!IS_ERR(clk))
+		of_clk_add_provider(node, of_clk_src_simple_get, clk);
+}
+
+__init void of_omap3_dpll_setup(struct device_node *node)
+{
+	/* XXX: to be done */
+}
+EXPORT_SYMBOL_GPL(of_omap3_dpll_setup);
+CLK_OF_DECLARE(omap3_dpll_clock, "ti,omap3-dpll-clock", of_omap3_dpll_setup);
+
+__init void of_omap4_dpll_setup(struct device_node *node)
+{
+	const struct clk_ops *ops;
+
+	ops = &dpll_ck_ops;
+
+	if (of_property_read_bool(node, "ti,dpll-regm4xen"))
+		ops = &dpll_m4xen_ck_ops;
+
+	if (of_property_read_bool(node, "ti,dpll-core"))
+		ops = &dpll_core_ck_ops;
+
+	if (of_property_read_bool(node, "ti,dpll-clk-x2")) {
+		of_omap_dpll_x2_setup(node);
+		return;
+	}
+
+	of_omap_dpll_setup(node, ops);
+}
+EXPORT_SYMBOL_GPL(of_omap4_dpll_setup);
+CLK_OF_DECLARE(omap4_dpll_clock, "ti,omap4-dpll-clock", of_omap4_dpll_setup);
+#endif