[3/3] clk: keystone: Add sci-clk driver support

Commit Message

Tero Kristo Oct. 21, 2016, 12:46 p.m. UTC

In K2G, the clock handling is done through firmware executing on a
separate core. Linux kernel needs to communicate to the firmware
through TI system control interface to access any power management
related resources, including clocks.

The keystone sci-clk driver does this, by communicating to the
firmware through the TI SCI driver. The driver adds support for
registering clocks through DT, and basic required clock operations
like prepare/get_rate, etc.

Signed-off-by: Tero Kristo <[e-mail]>
---
 MAINTAINERS                    |   1 +
 drivers/clk/Kconfig            |   9 +
 drivers/clk/keystone/Makefile  |   1 +
 drivers/clk/keystone/sci-clk.c | 589 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 600 insertions(+)
 create mode 100644 drivers/clk/keystone/sci-clk.c

Comments

Stephen Boyd Dec. 8, 2016, 12:13 a.m. UTC | #1

On 10/21, Tero Kristo wrote:
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 6a8ac04..dce08a7 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -169,6 +169,15 @@ config COMMON_CLK_NXP
>  	---help---
>  	  Support for clock providers on NXP platforms.
>  
> +config TI_SCI_CLK
> +	tristate "TI System Control Interface clock drivers"
> +	depends on (TI_SCI_PROTOCOL && COMMON_CLK_KEYSTONE) || COMPILE_TEST

Given that we depend on COMMON_CLK_KEYSTONE (just for the
Makefile dependency?) this should be moved to right below the
COMMON_CLK_KEYSTONE config. And we should consider making a
Kconfig file in drivers/clk/keystone/ to hold both those configs
instead of having them at the toplevel.

> +	default TI_SCI_PROTOCOL
> +	---help---
> +	  This adds the clock driver support over TI System Control Interface.
> +	  If you wish to use clock resources from the PMMC firmware, say Y.
> +	  Otherwise, say N.
> +
>  config COMMON_CLK_PALMAS
>  	tristate "Clock driver for TI Palmas devices"
>  	depends on MFD_PALMAS
> diff --git a/drivers/clk/keystone/Makefile b/drivers/clk/keystone/Makefile
> index 0477cf6..0e7993d 100644
> --- a/drivers/clk/keystone/Makefile
> +++ b/drivers/clk/keystone/Makefile
> @@ -1 +1,2 @@
>  obj-y			+= pll.o gate.o
> +obj-$(CONFIG_TI_SCI_CLK)	+= sci-clk.o
> diff --git a/drivers/clk/keystone/sci-clk.c b/drivers/clk/keystone/sci-clk.c
> new file mode 100644
> index 0000000..f6af5bd
> --- /dev/null
> +++ b/drivers/clk/keystone/sci-clk.c
> @@ -0,0 +1,589 @@
[...]
> +
> +/**
> + * sci_clk_recalc_rate - Get clock rate for a TI SCI clock
> + * @hw: clock to get rate for
> + * @parent_rate: parent rate provided by common clock framework, not used
> + *
> + * Gets the current clock rate of a TI SCI clock. Returns the current
> + * clock rate, or zero in failure.
> + */
> +static unsigned long sci_clk_recalc_rate(struct clk_hw *hw,
> +					 unsigned long parent_rate)
> +{
> +	struct sci_clk *clk = to_sci_clk(hw);
> +	u64 freq;
> +	int ret;
> +
> +	ret = clk->provider->ops->get_freq(clk->provider->sci, clk->dev_id,
> +					   clk->clk_id, &freq);
> +	if (ret) {
> +		dev_err(clk->provider->dev,
> +			"recalc-rate failed for dev=%d, clk=%d, ret=%d\n",
> +			clk->dev_id, clk->clk_id, ret);
> +		return 0;
> +	}
> +
> +	return (u32)freq;

Do we need the cast? sizeof(u32) doesn't always equal
sizeof(unsigned long).

> +
> +/**
> + * _sci_clk_get - Gets a handle for an SCI clock
> + * @provider: Handle to SCI clock provider
> + * @dev_id: device ID for the clock to register
> + * @clk_id: clock ID for the clock to register
> + *
> + * Gets a handle to an existing TI SCI hw clock, or builds a new clock
> + * entry and registers it with the common clock framework. Called from
> + * the common clock framework, when a corresponding of_clk_get call is
> + * executed, or recursively from itself when parsing parent clocks.
> + * Returns a pointer to the hw clock struct, or ERR_PTR value in failure.
> + */
> +static struct clk_hw *_sci_clk_build(struct sci_clk_provider *provider,
> +				     u16 dev_id, u8 clk_id)
> +{
> +	struct clk_init_data init = { NULL };
> +	struct sci_clk *sci_clk = NULL;
> +	char *name = NULL;
> +	char **parent_names = NULL;
> +	int i;
> +	int ret;
> +
> +	sci_clk = devm_kzalloc(provider->dev, sizeof(*sci_clk), GFP_KERNEL);
> +	if (!sci_clk)
> +		return ERR_PTR(-ENOMEM);
> +
> +	sci_clk->dev_id = dev_id;
> +	sci_clk->clk_id = clk_id;
> +	sci_clk->provider = provider;
> +
> +	ret = provider->ops->get_num_parents(provider->sci, dev_id,
> +					     clk_id,
> +					     &init.num_parents);
> +	if (ret)
> +		goto err;
> +
> +	name = kasprintf(GFP_KERNEL, "%s:%d:%d", dev_name(provider->dev),
> +			 sci_clk->dev_id, sci_clk->clk_id);
> +
> +	init.name = name;
> +
> +	if (init.num_parents < 2)
> +		init.num_parents = 0;

This deserves a comment. Why is num_parents == 1 the same as
num_parents == 0?

> +
> +	if (init.num_parents) {
> +		parent_names = devm_kcalloc(provider->dev, init.num_parents,
> +					    sizeof(char *), GFP_KERNEL);
> +
> +		if (!parent_names) {
> +			ret = -ENOMEM;
> +			goto err;
> +		}
> +
> +		for (i = 0; i < init.num_parents; i++) {
> +			char *parent_name;
> +
> +			parent_name = kasprintf(GFP_KERNEL, "%s:%d:%d",
> +						dev_name(provider->dev),
> +						sci_clk->dev_id,
> +						sci_clk->clk_id + 1 + i);
> +			if (!parent_name) {
> +				ret = -ENOMEM;
> +				goto err;
> +			}
> +			parent_names[i] = parent_name;
> +		}
> +		init.parent_names = (const char * const *)parent_names;

Does that really need a cast?

> +	}
> +
> +	init.ops = &sci_clk_ops;
> +	sci_clk->hw.init = &init;
> +
> +	ret = devm_clk_hw_register(provider->dev, &sci_clk->hw);
> +	if (ret) {
> +		dev_err(provider->dev, "failed clk register with %d\n", ret);
> +		goto err;
> +	}
> +	kfree(name);
> +
> +	return &sci_clk->hw;
> +
> +err:
> +	if (parent_names) {
> +		for (i = 0; i < init.num_parents; i++)
> +			devm_kfree(provider->dev, parent_names[i]);
> +
> +		devm_kfree(provider->dev, parent_names);

Shouldn't we be freeing the parent names all the time? It should
be deep copied in the framework.

> +	}
> +
> +	devm_kfree(provider->dev, sci_clk);
> +
> +	kfree(name);
> +
> +	return ERR_PTR(ret);
> +}
[..]
> +
> +static int ti_sci_init_clocks(struct sci_clk_provider *p)
> +{
> +	struct sci_clk_data *data = p->clocks;
> +	struct clk_hw *hw;
> +	int i;
> +
> +	while (data->num_clks) {
> +		data->clocks = devm_kcalloc(p->dev, data->num_clks,
> +					    sizeof(struct sci_clk),
> +					    GFP_KERNEL);
> +		if (!data->clocks)
> +			return -ENOMEM;
> +
> +		for (i = 0; i < data->num_clks; i++) {
> +			hw = _sci_clk_build(p, data->dev, i);
> +			if (!IS_ERR(hw)) {
> +				data->clocks[i] = hw;
> +				continue;
> +			}
> +
> +			/* Skip any holes in the clock lists */
> +			if (PTR_ERR(hw) == -ENODEV)

Does this happen? I don't see where _sci_clk_build() returns
-ENODEV.

> +				continue;
> +
> +			return PTR_ERR(hw);
> +		}
> +		data++;
> +	}
> +
> +	return 0;
> +}
> +

> +
> +/**
> + * ti_sci_clk_probe - Probe function for the TI SCI clock driver
> + * @pdev: platform device pointer to be probed
> + *
> + * Probes the TI SCI clock device. Allocates a new clock provider
> + * and registers this to the common clock framework. Also applies
> + * any required flags to the identified clocks via clock lists
> + * supplied from DT. Returns 0 for success, negative error value
> + * for failure.
> + */
> +static int ti_sci_clk_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct sci_clk_provider *provider;
> +	const struct ti_sci_handle *handle;
> +	struct sci_clk_data *data;
> +	int ret;
> +
> +	data = (struct sci_clk_data *)
> +		of_match_node(ti_sci_clk_of_match, np)->data;

Just use of_device_get_match_data() instead.

> +
> +	handle = devm_ti_sci_get_handle(dev);
> +	if (IS_ERR(handle))
> +		return PTR_ERR(handle);
> +
> +	provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL);
> +	if (!provider)
> +		return -ENOMEM;
> +
> +	provider->clocks = data;
> +
> +	provider->sci = handle;
> +	provider->ops = &handle->ops.clk_ops;
> +	provider->dev = dev;
> +
> +	ti_sci_init_clocks(provider);

And if this fails?

> +
> +	ret = of_clk_add_hw_provider(np, sci_clk_get, provider);
> +	if (ret)
> +		return ret;
> +
> +	return 0;

Just "return of_clk_add_hw_provider()" please.

> +}

Tero Kristo Dec. 8, 2016, 10:45 a.m. UTC | #2

On 08/12/16 02:13, Stephen Boyd wrote:
> On 10/21, Tero Kristo wrote:
>> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
>> index 6a8ac04..dce08a7 100644
>> --- a/drivers/clk/Kconfig
>> +++ b/drivers/clk/Kconfig
>> @@ -169,6 +169,15 @@ config COMMON_CLK_NXP
>>  	---help---
>>  	  Support for clock providers on NXP platforms.
>>
>> +config TI_SCI_CLK
>> +	tristate "TI System Control Interface clock drivers"
>> +	depends on (TI_SCI_PROTOCOL && COMMON_CLK_KEYSTONE) || COMPILE_TEST
>
> Given that we depend on COMMON_CLK_KEYSTONE (just for the
> Makefile dependency?) this should be moved to right below the
> COMMON_CLK_KEYSTONE config. And we should consider making a
> Kconfig file in drivers/clk/keystone/ to hold both those configs
> instead of having them at the toplevel.

Its a makefile dependency only right now. I'll have a look at how to 
handle this properly.

>
>> +	default TI_SCI_PROTOCOL
>> +	---help---
>> +	  This adds the clock driver support over TI System Control Interface.
>> +	  If you wish to use clock resources from the PMMC firmware, say Y.
>> +	  Otherwise, say N.
>> +
>>  config COMMON_CLK_PALMAS
>>  	tristate "Clock driver for TI Palmas devices"
>>  	depends on MFD_PALMAS
>> diff --git a/drivers/clk/keystone/Makefile b/drivers/clk/keystone/Makefile
>> index 0477cf6..0e7993d 100644
>> --- a/drivers/clk/keystone/Makefile
>> +++ b/drivers/clk/keystone/Makefile
>> @@ -1 +1,2 @@
>>  obj-y			+= pll.o gate.o
>> +obj-$(CONFIG_TI_SCI_CLK)	+= sci-clk.o
>> diff --git a/drivers/clk/keystone/sci-clk.c b/drivers/clk/keystone/sci-clk.c
>> new file mode 100644
>> index 0000000..f6af5bd
>> --- /dev/null
>> +++ b/drivers/clk/keystone/sci-clk.c
>> @@ -0,0 +1,589 @@
> [...]
>> +
>> +/**
>> + * sci_clk_recalc_rate - Get clock rate for a TI SCI clock
>> + * @hw: clock to get rate for
>> + * @parent_rate: parent rate provided by common clock framework, not used
>> + *
>> + * Gets the current clock rate of a TI SCI clock. Returns the current
>> + * clock rate, or zero in failure.
>> + */
>> +static unsigned long sci_clk_recalc_rate(struct clk_hw *hw,
>> +					 unsigned long parent_rate)
>> +{
>> +	struct sci_clk *clk = to_sci_clk(hw);
>> +	u64 freq;
>> +	int ret;
>> +
>> +	ret = clk->provider->ops->get_freq(clk->provider->sci, clk->dev_id,
>> +					   clk->clk_id, &freq);
>> +	if (ret) {
>> +		dev_err(clk->provider->dev,
>> +			"recalc-rate failed for dev=%d, clk=%d, ret=%d\n",
>> +			clk->dev_id, clk->clk_id, ret);
>> +		return 0;
>> +	}
>> +
>> +	return (u32)freq;
>
> Do we need the cast? sizeof(u32) doesn't always equal
> sizeof(unsigned long).

Hmm, not sure where that came from. But yea, can be dropped.


>
>> +
>> +/**
>> + * _sci_clk_get - Gets a handle for an SCI clock
>> + * @provider: Handle to SCI clock provider
>> + * @dev_id: device ID for the clock to register
>> + * @clk_id: clock ID for the clock to register
>> + *
>> + * Gets a handle to an existing TI SCI hw clock, or builds a new clock
>> + * entry and registers it with the common clock framework. Called from
>> + * the common clock framework, when a corresponding of_clk_get call is
>> + * executed, or recursively from itself when parsing parent clocks.
>> + * Returns a pointer to the hw clock struct, or ERR_PTR value in failure.
>> + */
>> +static struct clk_hw *_sci_clk_build(struct sci_clk_provider *provider,
>> +				     u16 dev_id, u8 clk_id)
>> +{
>> +	struct clk_init_data init = { NULL };
>> +	struct sci_clk *sci_clk = NULL;
>> +	char *name = NULL;
>> +	char **parent_names = NULL;
>> +	int i;
>> +	int ret;
>> +
>> +	sci_clk = devm_kzalloc(provider->dev, sizeof(*sci_clk), GFP_KERNEL);
>> +	if (!sci_clk)
>> +		return ERR_PTR(-ENOMEM);
>> +
>> +	sci_clk->dev_id = dev_id;
>> +	sci_clk->clk_id = clk_id;
>> +	sci_clk->provider = provider;
>> +
>> +	ret = provider->ops->get_num_parents(provider->sci, dev_id,
>> +					     clk_id,
>> +					     &init.num_parents);
>> +	if (ret)
>> +		goto err;
>> +
>> +	name = kasprintf(GFP_KERNEL, "%s:%d:%d", dev_name(provider->dev),
>> +			 sci_clk->dev_id, sci_clk->clk_id);
>> +
>> +	init.name = name;
>> +
>> +	if (init.num_parents < 2)
>> +		init.num_parents = 0;
>
> This deserves a comment. Why is num_parents == 1 the same as
> num_parents == 0?

I'll add a comment on this. Basically some clocks can be root clocks 
which don't have parents, and we only want to have parent control for 
clocks that can switch their parent. This is kind of a quirk of the 
firmware.

>
>> +
>> +	if (init.num_parents) {
>> +		parent_names = devm_kcalloc(provider->dev, init.num_parents,
>> +					    sizeof(char *), GFP_KERNEL);
>> +
>> +		if (!parent_names) {
>> +			ret = -ENOMEM;
>> +			goto err;
>> +		}
>> +
>> +		for (i = 0; i < init.num_parents; i++) {
>> +			char *parent_name;
>> +
>> +			parent_name = kasprintf(GFP_KERNEL, "%s:%d:%d",
>> +						dev_name(provider->dev),
>> +						sci_clk->dev_id,
>> +						sci_clk->clk_id + 1 + i);
>> +			if (!parent_name) {
>> +				ret = -ENOMEM;
>> +				goto err;
>> +			}
>> +			parent_names[i] = parent_name;
>> +		}
>> +		init.parent_names = (const char * const *)parent_names;
>
> Does that really need a cast?

Doesn't seem like so... I think without this it was generating some 
checkpatch issue sometime back, but doesn't seem to be the case anymore.

>
>> +	}
>> +
>> +	init.ops = &sci_clk_ops;
>> +	sci_clk->hw.init = &init;
>> +
>> +	ret = devm_clk_hw_register(provider->dev, &sci_clk->hw);
>> +	if (ret) {
>> +		dev_err(provider->dev, "failed clk register with %d\n", ret);
>> +		goto err;
>> +	}
>> +	kfree(name);
>> +
>> +	return &sci_clk->hw;
>> +
>> +err:
>> +	if (parent_names) {
>> +		for (i = 0; i < init.num_parents; i++)
>> +			devm_kfree(provider->dev, parent_names[i]);
>> +
>> +		devm_kfree(provider->dev, parent_names);
>
> Shouldn't we be freeing the parent names all the time? It should
> be deep copied in the framework.

I'll check this.

>
>> +	}
>> +
>> +	devm_kfree(provider->dev, sci_clk);
>> +
>> +	kfree(name);
>> +
>> +	return ERR_PTR(ret);
>> +}
> [..]
>> +
>> +static int ti_sci_init_clocks(struct sci_clk_provider *p)
>> +{
>> +	struct sci_clk_data *data = p->clocks;
>> +	struct clk_hw *hw;
>> +	int i;
>> +
>> +	while (data->num_clks) {
>> +		data->clocks = devm_kcalloc(p->dev, data->num_clks,
>> +					    sizeof(struct sci_clk),
>> +					    GFP_KERNEL);
>> +		if (!data->clocks)
>> +			return -ENOMEM;
>> +
>> +		for (i = 0; i < data->num_clks; i++) {
>> +			hw = _sci_clk_build(p, data->dev, i);
>> +			if (!IS_ERR(hw)) {
>> +				data->clocks[i] = hw;
>> +				continue;
>> +			}
>> +
>> +			/* Skip any holes in the clock lists */
>> +			if (PTR_ERR(hw) == -ENODEV)
>
> Does this happen? I don't see where _sci_clk_build() returns
> -ENODEV.

Yes, it can and will happen. get_num_parents() called by sci_clk_build 
will return ENODEV for device/clock pairs that don't exist.

>
>> +				continue;
>> +
>> +			return PTR_ERR(hw);
>> +		}
>> +		data++;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>
>> +
>> +/**
>> + * ti_sci_clk_probe - Probe function for the TI SCI clock driver
>> + * @pdev: platform device pointer to be probed
>> + *
>> + * Probes the TI SCI clock device. Allocates a new clock provider
>> + * and registers this to the common clock framework. Also applies
>> + * any required flags to the identified clocks via clock lists
>> + * supplied from DT. Returns 0 for success, negative error value
>> + * for failure.
>> + */
>> +static int ti_sci_clk_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct device_node *np = dev->of_node;
>> +	struct sci_clk_provider *provider;
>> +	const struct ti_sci_handle *handle;
>> +	struct sci_clk_data *data;
>> +	int ret;
>> +
>> +	data = (struct sci_clk_data *)
>> +		of_match_node(ti_sci_clk_of_match, np)->data;
>
> Just use of_device_get_match_data() instead.

All righty.

>
>> +
>> +	handle = devm_ti_sci_get_handle(dev);
>> +	if (IS_ERR(handle))
>> +		return PTR_ERR(handle);
>> +
>> +	provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL);
>> +	if (!provider)
>> +		return -ENOMEM;
>> +
>> +	provider->clocks = data;
>> +
>> +	provider->sci = handle;
>> +	provider->ops = &handle->ops.clk_ops;
>> +	provider->dev = dev;
>> +
>> +	ti_sci_init_clocks(provider);
>
> And if this fails?

Yea this is kind of controversial. ti_sci_init_clocks() can fail if any 
of the clocks registered will fail. I decided to have it this way so 
that at least some clocks might work in failure cause, and you might 
have a booting device instead of total lock-up.

Obviously it could be done so that if any clock fails, we would 
de-register all clocks at that point, but personally I think this is a 
worse option.

ti_sci_init_clocks could probably be modified to continue registering 
clocks when a single clock fails though. Currently it aborts at first 
failure.

Thoughts on that?

>
>> +
>> +	ret = of_clk_add_hw_provider(np, sci_clk_get, provider);
>> +	if (ret)
>> +		return ret;
>> +
>> +	return 0;
>
> Just "return of_clk_add_hw_provider()" please.

True that, will fix.

-Tero

Stephen Boyd Dec. 8, 2016, 9:10 p.m. UTC | #3

On 12/08, Tero Kristo wrote:
> On 08/12/16 02:13, Stephen Boyd wrote:
> >On 10/21, Tero Kristo wrote:
> >>diff --git a/drivers/clk/keystone/sci-clk.c b/drivers/clk/keystone/sci-clk.c
> >>new file mode 100644
> >>index 0000000..f6af5bd
> >>--- /dev/null
> >>+++ b/drivers/clk/keystone/sci-clk.c
> 
> >
> >>+
> >>+	handle = devm_ti_sci_get_handle(dev);
> >>+	if (IS_ERR(handle))
> >>+		return PTR_ERR(handle);
> >>+
> >>+	provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL);
> >>+	if (!provider)
> >>+		return -ENOMEM;
> >>+
> >>+	provider->clocks = data;
> >>+
> >>+	provider->sci = handle;
> >>+	provider->ops = &handle->ops.clk_ops;
> >>+	provider->dev = dev;
> >>+
> >>+	ti_sci_init_clocks(provider);
> >
> >And if this fails?
> 
> Yea this is kind of controversial. ti_sci_init_clocks() can fail if
> any of the clocks registered will fail. I decided to have it this
> way so that at least some clocks might work in failure cause, and
> you might have a booting device instead of total lock-up.
> 
> Obviously it could be done so that if any clock fails, we would
> de-register all clocks at that point, but personally I think this is
> a worse option.
> 
> ti_sci_init_clocks could probably be modified to continue
> registering clocks when a single clock fails though. Currently it
> aborts at first failure.
> 

That sounds like a better approach if we don't care about
failures to register a clock. Returning a value from a function
and not using it isn't really a great design.

I worry that if we start returning errors from clk_hw_register()
that something will go wrong though, so really I don't know why
we want to ignore errors at all. Just for debugging a boot hang?
Can't we use early console to at least see that this driver is
failing to probe and debug that way?

Tero Kristo Dec. 9, 2016, 8:05 a.m. UTC | #4

On 08/12/16 23:10, Stephen Boyd wrote:
> On 12/08, Tero Kristo wrote:
>> On 08/12/16 02:13, Stephen Boyd wrote:
>>> On 10/21, Tero Kristo wrote:
>>>> diff --git a/drivers/clk/keystone/sci-clk.c b/drivers/clk/keystone/sci-clk.c
>>>> new file mode 100644
>>>> index 0000000..f6af5bd
>>>> --- /dev/null
>>>> +++ b/drivers/clk/keystone/sci-clk.c
>>
>>>
>>>> +
>>>> +	handle = devm_ti_sci_get_handle(dev);
>>>> +	if (IS_ERR(handle))
>>>> +		return PTR_ERR(handle);
>>>> +
>>>> +	provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL);
>>>> +	if (!provider)
>>>> +		return -ENOMEM;
>>>> +
>>>> +	provider->clocks = data;
>>>> +
>>>> +	provider->sci = handle;
>>>> +	provider->ops = &handle->ops.clk_ops;
>>>> +	provider->dev = dev;
>>>> +
>>>> +	ti_sci_init_clocks(provider);
>>>
>>> And if this fails?
>>
>> Yea this is kind of controversial. ti_sci_init_clocks() can fail if
>> any of the clocks registered will fail. I decided to have it this
>> way so that at least some clocks might work in failure cause, and
>> you might have a booting device instead of total lock-up.
>>
>> Obviously it could be done so that if any clock fails, we would
>> de-register all clocks at that point, but personally I think this is
>> a worse option.
>>
>> ti_sci_init_clocks could probably be modified to continue
>> registering clocks when a single clock fails though. Currently it
>> aborts at first failure.
>>
>
> That sounds like a better approach if we don't care about
> failures to register a clock. Returning a value from a function
> and not using it isn't really a great design.
>
> I worry that if we start returning errors from clk_hw_register()
> that something will go wrong though, so really I don't know why
> we want to ignore errors at all. Just for debugging a boot hang?
> Can't we use early console to at least see that this driver is
> failing to probe and debug that way?

Early console can be used to debug that, but it is kind of annoying to 
recompile most of the kernel when you suddenly need to use it.

How about modifying the ti_sci_init_clocks func to print an error for 
each failed clock?

If you insist on aborting the probe though if a single clock fails, I 
can do that also.

-Tero

Stephen Boyd Dec. 12, 2016, 7:38 p.m. UTC | #5

On 12/09, Tero Kristo wrote:
> On 08/12/16 23:10, Stephen Boyd wrote:
> >On 12/08, Tero Kristo wrote:
> >>On 08/12/16 02:13, Stephen Boyd wrote:
> >>>On 10/21, Tero Kristo wrote:
> >>>>diff --git a/drivers/clk/keystone/sci-clk.c b/drivers/clk/keystone/sci-clk.c
> >>>>new file mode 100644
> >>>>index 0000000..f6af5bd
> >>>>--- /dev/null
> >>>>+++ b/drivers/clk/keystone/sci-clk.c
> >>
> >>>
> >>>>+
> >>>>+	handle = devm_ti_sci_get_handle(dev);
> >>>>+	if (IS_ERR(handle))
> >>>>+		return PTR_ERR(handle);
> >>>>+
> >>>>+	provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL);
> >>>>+	if (!provider)
> >>>>+		return -ENOMEM;
> >>>>+
> >>>>+	provider->clocks = data;
> >>>>+
> >>>>+	provider->sci = handle;
> >>>>+	provider->ops = &handle->ops.clk_ops;
> >>>>+	provider->dev = dev;
> >>>>+
> >>>>+	ti_sci_init_clocks(provider);
> >>>
> >>>And if this fails?
> >>
> >>Yea this is kind of controversial. ti_sci_init_clocks() can fail if
> >>any of the clocks registered will fail. I decided to have it this
> >>way so that at least some clocks might work in failure cause, and
> >>you might have a booting device instead of total lock-up.
> >>
> >>Obviously it could be done so that if any clock fails, we would
> >>de-register all clocks at that point, but personally I think this is
> >>a worse option.
> >>
> >>ti_sci_init_clocks could probably be modified to continue
> >>registering clocks when a single clock fails though. Currently it
> >>aborts at first failure.
> >>
> >
> >That sounds like a better approach if we don't care about
> >failures to register a clock. Returning a value from a function
> >and not using it isn't really a great design.
> >
> >I worry that if we start returning errors from clk_hw_register()
> >that something will go wrong though, so really I don't know why
> >we want to ignore errors at all. Just for debugging a boot hang?
> >Can't we use early console to at least see that this driver is
> >failing to probe and debug that way?
> 
> Early console can be used to debug that, but it is kind of annoying
> to recompile most of the kernel when you suddenly need to use it.

I thought SERIAL_EARLYCON was selected by drivers that support
it? So there shouldn't be any rebuilding required.

> 
> How about modifying the ti_sci_init_clocks func to print an error
> for each failed clock?

Ok that's fine too. I'd prefer the function had a return type of
void if we're not planning on using the return value, that's all.

Tero Kristo Dec. 13, 2016, 9:01 a.m. UTC | #6

On 12/12/16 21:38, Stephen Boyd wrote:
> On 12/09, Tero Kristo wrote:
>> On 08/12/16 23:10, Stephen Boyd wrote:
>>> On 12/08, Tero Kristo wrote:
>>>> On 08/12/16 02:13, Stephen Boyd wrote:
>>>>> On 10/21, Tero Kristo wrote:
>>>>>> diff --git a/drivers/clk/keystone/sci-clk.c b/drivers/clk/keystone/sci-clk.c
>>>>>> new file mode 100644
>>>>>> index 0000000..f6af5bd
>>>>>> --- /dev/null
>>>>>> +++ b/drivers/clk/keystone/sci-clk.c
>>>>
>>>>>
>>>>>> +
>>>>>> +	handle = devm_ti_sci_get_handle(dev);
>>>>>> +	if (IS_ERR(handle))
>>>>>> +		return PTR_ERR(handle);
>>>>>> +
>>>>>> +	provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL);
>>>>>> +	if (!provider)
>>>>>> +		return -ENOMEM;
>>>>>> +
>>>>>> +	provider->clocks = data;
>>>>>> +
>>>>>> +	provider->sci = handle;
>>>>>> +	provider->ops = &handle->ops.clk_ops;
>>>>>> +	provider->dev = dev;
>>>>>> +
>>>>>> +	ti_sci_init_clocks(provider);
>>>>>
>>>>> And if this fails?
>>>>
>>>> Yea this is kind of controversial. ti_sci_init_clocks() can fail if
>>>> any of the clocks registered will fail. I decided to have it this
>>>> way so that at least some clocks might work in failure cause, and
>>>> you might have a booting device instead of total lock-up.
>>>>
>>>> Obviously it could be done so that if any clock fails, we would
>>>> de-register all clocks at that point, but personally I think this is
>>>> a worse option.
>>>>
>>>> ti_sci_init_clocks could probably be modified to continue
>>>> registering clocks when a single clock fails though. Currently it
>>>> aborts at first failure.
>>>>
>>>
>>> That sounds like a better approach if we don't care about
>>> failures to register a clock. Returning a value from a function
>>> and not using it isn't really a great design.
>>>
>>> I worry that if we start returning errors from clk_hw_register()
>>> that something will go wrong though, so really I don't know why
>>> we want to ignore errors at all. Just for debugging a boot hang?
>>> Can't we use early console to at least see that this driver is
>>> failing to probe and debug that way?
>>
>> Early console can be used to debug that, but it is kind of annoying
>> to recompile most of the kernel when you suddenly need to use it.
>
> I thought SERIAL_EARLYCON was selected by drivers that support
> it? So there shouldn't be any rebuilding required.

Actually you can probably ignore my comment, I was just speaking out of 
OMAP experience where the clocks are initialized very early, but this 
doesn't apply to keystone. Sci-clock is a proper driver now with proper 
probe etc. in place so my comment here is invalid.

>
>>
>> How about modifying the ti_sci_init_clocks func to print an error
>> for each failed clock?
>
> Ok that's fine too. I'd prefer the function had a return type of
> void if we're not planning on using the return value, that's all.

Ok, I'll see which way I go in v2 of the series, but seems I can pick 
either your original proposal or mine.

-Tero

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 960deb6..3f51df6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11897,6 +11897,7 @@  F:	include/dt-bindings/genpd/k2g.h
 F:	drivers/soc/ti/ti_sci_pm_domains.c
 F:	Documentation/devicetree/bindings/clock/ti,sci-clk.txt
 F:	include/dt-bindings/clock/k2g.h
+F:	drivers/clk/keystone/sci-clk.c
 
 THANKO'S RAREMONO AM/FM/SW RADIO RECEIVER USB DRIVER
 M:	Hans Verkuil <[e-mail]>
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 6a8ac04..dce08a7 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -169,6 +169,15 @@  config COMMON_CLK_NXP
 	---help---
 	  Support for clock providers on NXP platforms.
 
+config TI_SCI_CLK
+	tristate "TI System Control Interface clock drivers"
+	depends on (TI_SCI_PROTOCOL && COMMON_CLK_KEYSTONE) || COMPILE_TEST
+	default TI_SCI_PROTOCOL
+	---help---
+	  This adds the clock driver support over TI System Control Interface.
+	  If you wish to use clock resources from the PMMC firmware, say Y.
+	  Otherwise, say N.
+
 config COMMON_CLK_PALMAS
 	tristate "Clock driver for TI Palmas devices"
 	depends on MFD_PALMAS
diff --git a/drivers/clk/keystone/Makefile b/drivers/clk/keystone/Makefile
index 0477cf6..0e7993d 100644
--- a/drivers/clk/keystone/Makefile
+++ b/drivers/clk/keystone/Makefile
@@ -1 +1,2 @@ 
 obj-y			+= pll.o gate.o
+obj-$(CONFIG_TI_SCI_CLK)	+= sci-clk.o
diff --git a/drivers/clk/keystone/sci-clk.c b/drivers/clk/keystone/sci-clk.c
new file mode 100644
index 0000000..f6af5bd
--- /dev/null
+++ b/drivers/clk/keystone/sci-clk.c
@@ -0,0 +1,589 @@ 
+/*
+ * SCI Clock driver for keystone based devices
+ *
+ * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
+ *	Tero Kristo <[e-mail]>
+ *
+ * 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/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/soc/ti/ti_sci_protocol.h>
+#include <dt-bindings/clock/k2g.h>
+#include <dt-bindings/genpd/k2g.h>
+
+#define SCI_CLK_SSC_ENABLE		BIT(0)
+#define SCI_CLK_ALLOW_FREQ_CHANGE	BIT(1)
+#define SCI_CLK_INPUT_TERMINATION	BIT(2)
+
+/**
+ * struct sci_clk_data - TI SCI clock data
+ * @dev: device index
+ * @num_clks: number of clocks for this device
+ * @clocks: clocks array for this device
+ */
+struct sci_clk_data {
+	u16 dev;
+	u16 num_clks;
+	struct clk_hw **clocks;
+};
+
+/**
+ * struct sci_clk_provider - TI SCI clock provider representation
+ * @sci:    Handle to the System Control Interface protocol handler
+ * @ops:    Pointer to the SCI ops to be used by the clocks
+ * @dev:    Device pointer for the clock provider
+ * @clocks:	Clock data
+ */
+struct sci_clk_provider {
+	const struct ti_sci_handle *sci;
+	const struct ti_sci_clk_ops *ops;
+	struct device *dev;
+	struct sci_clk_data *clocks;
+};
+
+/**
+ * struct sci_clk - TI SCI clock representation
+ * @hw:		 Hardware clock cookie for common clock framework
+ * @dev_id:	 Device index
+ * @clk_id:	 Clock index
+ * @node:	 Clocks list link
+ * @provider:	 Master clock provider
+ * @flags:	 Flags for the clock
+ */
+struct sci_clk {
+	struct clk_hw hw;
+	u16 dev_id;
+	u8 clk_id;
+	struct list_head node;
+	struct sci_clk_provider *provider;
+	u8 flags;
+};
+
+#define to_sci_clk(_hw) container_of(_hw, struct sci_clk, hw)
+
+/**
+ * sci_clk_prepare - Prepare (enable) a TI SCI clock
+ * @hw: clock to prepare
+ *
+ * Prepares a clock to be actively used. Returns the SCI protocol status.
+ */
+static int sci_clk_prepare(struct clk_hw *hw)
+{
+	struct sci_clk *clk = to_sci_clk(hw);
+	bool enable_ssc = clk->flags & SCI_CLK_SSC_ENABLE;
+	bool allow_freq_change = clk->flags & SCI_CLK_ALLOW_FREQ_CHANGE;
+	bool input_termination = clk->flags & SCI_CLK_INPUT_TERMINATION;
+
+	return clk->provider->ops->get_clock(clk->provider->sci, clk->dev_id,
+					     clk->clk_id, enable_ssc,
+					     allow_freq_change,
+					     input_termination);
+}
+
+/**
+ * sci_clk_unprepare - Un-prepares (disables) a TI SCI clock
+ * @hw: clock to unprepare
+ *
+ * Un-prepares a clock from active state.
+ */
+static void sci_clk_unprepare(struct clk_hw *hw)
+{
+	struct sci_clk *clk = to_sci_clk(hw);
+	int ret;
+
+	ret = clk->provider->ops->put_clock(clk->provider->sci, clk->dev_id,
+					    clk->clk_id);
+	if (ret)
+		dev_err(clk->provider->dev,
+			"unprepare failed for dev=%d, clk=%d, ret=%d\n",
+			clk->dev_id, clk->clk_id, ret);
+}
+
+/**
+ * sci_clk_is_prepared - Check if a TI SCI clock is prepared or not
+ * @hw: clock to check status for
+ *
+ * Checks if a clock is prepared (enabled) in hardware. Returns non-zero
+ * value if clock is enabled, zero otherwise.
+ */
+static int sci_clk_is_prepared(struct clk_hw *hw)
+{
+	struct sci_clk *clk = to_sci_clk(hw);
+	bool req_state, current_state;
+	int ret;
+
+	ret = clk->provider->ops->is_on(clk->provider->sci, clk->dev_id,
+					clk->clk_id, &req_state,
+					&current_state);
+	if (ret) {
+		dev_err(clk->provider->dev,
+			"is_prepared failed for dev=%d, clk=%d, ret=%d\n",
+			clk->dev_id, clk->clk_id, ret);
+		return 0;
+	}
+
+	return req_state;
+}
+
+/**
+ * sci_clk_recalc_rate - Get clock rate for a TI SCI clock
+ * @hw: clock to get rate for
+ * @parent_rate: parent rate provided by common clock framework, not used
+ *
+ * Gets the current clock rate of a TI SCI clock. Returns the current
+ * clock rate, or zero in failure.
+ */
+static unsigned long sci_clk_recalc_rate(struct clk_hw *hw,
+					 unsigned long parent_rate)
+{
+	struct sci_clk *clk = to_sci_clk(hw);
+	u64 freq;
+	int ret;
+
+	ret = clk->provider->ops->get_freq(clk->provider->sci, clk->dev_id,
+					   clk->clk_id, &freq);
+	if (ret) {
+		dev_err(clk->provider->dev,
+			"recalc-rate failed for dev=%d, clk=%d, ret=%d\n",
+			clk->dev_id, clk->clk_id, ret);
+		return 0;
+	}
+
+	return (u32)freq;
+}
+
+/**
+ * sci_clk_determine_rate - Determines a clock rate a clock can be set to
+ * @hw: clock to change rate for
+ * @req: requested rate configuration for the clock
+ *
+ * Determines a suitable clock rate and parent for a TI SCI clock.
+ * The parent handling is un-used, as generally the parent clock rates
+ * are not known by the kernel; instead these are internally handled
+ * by the firmware. Returns 0 on success, negative error value on failure.
+ */
+static int sci_clk_determine_rate(struct clk_hw *hw,
+				  struct clk_rate_request *req)
+{
+	struct sci_clk *clk = to_sci_clk(hw);
+	int ret;
+	u64 new_rate;
+
+	ret = clk->provider->ops->get_best_match_freq(clk->provider->sci,
+						      clk->dev_id,
+						      clk->clk_id,
+						      req->min_rate,
+						      req->rate,
+						      req->max_rate,
+						      &new_rate);
+	if (ret) {
+		dev_err(clk->provider->dev,
+			"determine-rate failed for dev=%d, clk=%d, ret=%d\n",
+			clk->dev_id, clk->clk_id, ret);
+		return ret;
+	}
+
+	req->rate = new_rate;
+
+	return 0;
+}
+
+/**
+ * sci_clk_set_rate - Set rate for a TI SCI clock
+ * @hw: clock to change rate for
+ * @rate: target rate for the clock
+ * @parent_rate: rate of the clock parent, not used for TI SCI clocks
+ *
+ * Sets a clock frequency for a TI SCI clock. Returns the TI SCI
+ * protocol status.
+ */
+static int sci_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+			    unsigned long parent_rate)
+{
+	struct sci_clk *clk = to_sci_clk(hw);
+
+	return clk->provider->ops->set_freq(clk->provider->sci, clk->dev_id,
+					    clk->clk_id, rate, rate, rate);
+}
+
+/**
+ * sci_clk_get_parent - Get the current parent of a TI SCI clock
+ * @hw: clock to get parent for
+ *
+ * Returns the index of the currently selected parent for a TI SCI clock.
+ */
+static u8 sci_clk_get_parent(struct clk_hw *hw)
+{
+	struct sci_clk *clk = to_sci_clk(hw);
+	u8 parent_id;
+	int ret;
+
+	ret = clk->provider->ops->get_parent(clk->provider->sci, clk->dev_id,
+					     clk->clk_id, &parent_id);
+	if (ret) {
+		dev_err(clk->provider->dev,
+			"get-parent failed for dev=%d, clk=%d, ret=%d\n",
+			clk->dev_id, clk->clk_id, ret);
+		return 0;
+	}
+
+	return parent_id - clk->clk_id - 1;
+}
+
+/**
+ * sci_clk_set_parent - Set the parent of a TI SCI clock
+ * @hw: clock to set parent for
+ * @index: new parent index for the clock
+ *
+ * Sets the parent of a TI SCI clock. Return TI SCI protocol status.
+ */
+static int sci_clk_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct sci_clk *clk = to_sci_clk(hw);
+
+	return clk->provider->ops->set_parent(clk->provider->sci, clk->dev_id,
+					      clk->clk_id,
+					      index + 1 + clk->clk_id);
+}
+
+static const struct clk_ops sci_clk_ops = {
+	.prepare = sci_clk_prepare,
+	.unprepare = sci_clk_unprepare,
+	.is_prepared = sci_clk_is_prepared,
+	.recalc_rate = sci_clk_recalc_rate,
+	.determine_rate = sci_clk_determine_rate,
+	.set_rate = sci_clk_set_rate,
+	.get_parent = sci_clk_get_parent,
+	.set_parent = sci_clk_set_parent,
+};
+
+/**
+ * _sci_clk_get - Gets a handle for an SCI clock
+ * @provider: Handle to SCI clock provider
+ * @dev_id: device ID for the clock to register
+ * @clk_id: clock ID for the clock to register
+ *
+ * Gets a handle to an existing TI SCI hw clock, or builds a new clock
+ * entry and registers it with the common clock framework. Called from
+ * the common clock framework, when a corresponding of_clk_get call is
+ * executed, or recursively from itself when parsing parent clocks.
+ * Returns a pointer to the hw clock struct, or ERR_PTR value in failure.
+ */
+static struct clk_hw *_sci_clk_build(struct sci_clk_provider *provider,
+				     u16 dev_id, u8 clk_id)
+{
+	struct clk_init_data init = { NULL };
+	struct sci_clk *sci_clk = NULL;
+	char *name = NULL;
+	char **parent_names = NULL;
+	int i;
+	int ret;
+
+	sci_clk = devm_kzalloc(provider->dev, sizeof(*sci_clk), GFP_KERNEL);
+	if (!sci_clk)
+		return ERR_PTR(-ENOMEM);
+
+	sci_clk->dev_id = dev_id;
+	sci_clk->clk_id = clk_id;
+	sci_clk->provider = provider;
+
+	ret = provider->ops->get_num_parents(provider->sci, dev_id,
+					     clk_id,
+					     &init.num_parents);
+	if (ret)
+		goto err;
+
+	name = kasprintf(GFP_KERNEL, "%s:%d:%d", dev_name(provider->dev),
+			 sci_clk->dev_id, sci_clk->clk_id);
+
+	init.name = name;
+
+	if (init.num_parents < 2)
+		init.num_parents = 0;
+
+	if (init.num_parents) {
+		parent_names = devm_kcalloc(provider->dev, init.num_parents,
+					    sizeof(char *), GFP_KERNEL);
+
+		if (!parent_names) {
+			ret = -ENOMEM;
+			goto err;
+		}
+
+		for (i = 0; i < init.num_parents; i++) {
+			char *parent_name;
+
+			parent_name = kasprintf(GFP_KERNEL, "%s:%d:%d",
+						dev_name(provider->dev),
+						sci_clk->dev_id,
+						sci_clk->clk_id + 1 + i);
+			if (!parent_name) {
+				ret = -ENOMEM;
+				goto err;
+			}
+			parent_names[i] = parent_name;
+		}
+		init.parent_names = (const char * const *)parent_names;
+	}
+
+	init.ops = &sci_clk_ops;
+	sci_clk->hw.init = &init;
+
+	ret = devm_clk_hw_register(provider->dev, &sci_clk->hw);
+	if (ret) {
+		dev_err(provider->dev, "failed clk register with %d\n", ret);
+		goto err;
+	}
+	kfree(name);
+
+	return &sci_clk->hw;
+
+err:
+	if (parent_names) {
+		for (i = 0; i < init.num_parents; i++)
+			devm_kfree(provider->dev, parent_names[i]);
+
+		devm_kfree(provider->dev, parent_names);
+	}
+
+	devm_kfree(provider->dev, sci_clk);
+
+	kfree(name);
+
+	return ERR_PTR(ret);
+}
+
+/**
+ * sci_clk_get - Xlate function for getting clock handles
+ * @clkspec: device tree clock specifier
+ * @data: pointer to the clock provider
+ *
+ * Xlate function for retrieving clock TI SCI hw clock handles based on
+ * device tree clock specifier. Called from the common clock framework,
+ * when a corresponding of_clk_get call is executed. Returns a pointer
+ * to the TI SCI hw clock struct, or ERR_PTR value in failure.
+ */
+static struct clk_hw *sci_clk_get(struct of_phandle_args *clkspec, void *data)
+{
+	struct sci_clk_provider *provider = data;
+	u16 dev_id;
+	u8 clk_id;
+	struct sci_clk_data *clks = provider->clocks;
+
+	if (clkspec->args_count != 2)
+		return ERR_PTR(-EINVAL);
+
+	dev_id = clkspec->args[0];
+	clk_id = clkspec->args[1];
+
+	while (clks->num_clks) {
+		if (clks->dev == dev_id) {
+			if (clk_id >= clks->num_clks)
+				return ERR_PTR(-EINVAL);
+
+			return clks->clocks[clk_id];
+		}
+
+		clks++;
+	}
+
+	return ERR_PTR(-ENODEV);
+}
+
+static int ti_sci_init_clocks(struct sci_clk_provider *p)
+{
+	struct sci_clk_data *data = p->clocks;
+	struct clk_hw *hw;
+	int i;
+
+	while (data->num_clks) {
+		data->clocks = devm_kcalloc(p->dev, data->num_clks,
+					    sizeof(struct sci_clk),
+					    GFP_KERNEL);
+		if (!data->clocks)
+			return -ENOMEM;
+
+		for (i = 0; i < data->num_clks; i++) {
+			hw = _sci_clk_build(p, data->dev, i);
+			if (!IS_ERR(hw)) {
+				data->clocks[i] = hw;
+				continue;
+			}
+
+			/* Skip any holes in the clock lists */
+			if (PTR_ERR(hw) == -ENODEV)
+				continue;
+
+			return PTR_ERR(hw);
+		}
+		data++;
+	}
+
+	return 0;
+}
+
+static const struct sci_clk_data k2g_clk_data[] = {
+	{ .dev = K2G_DEV_PMMC0, .num_clks = K2G_DEV_PMMC_MPM_DAP_CLK + 1 },
+	{ .dev = K2G_DEV_MLB0, .num_clks = K2G_DEV_MLB_MLBP_IO_CLK + 1 },
+	{ .dev = K2G_DEV_DSS0, .num_clks = K2G_DEV_DSS_PI_DSS_VP_CLK + 1 },
+	{ .dev = K2G_DEV_MCBSP0, .num_clks = K2G_DEV_MCBSP_CLKS_PARENT_UART_PLL + 1 },
+	{ .dev = K2G_DEV_MCASP0, .num_clks = K2G_DEV_MCASP_AUX_CLK_PARENT_UART_PLL + 1 },
+	{ .dev = K2G_DEV_MCASP1, .num_clks = K2G_DEV_MCASP_AUX_CLK_PARENT_UART_PLL + 1 },
+	{ .dev = K2G_DEV_MCASP2, .num_clks = K2G_DEV_MCASP_AUX_CLK_PARENT_UART_PLL + 1 },
+	{ .dev = K2G_DEV_DCAN0, .num_clks = K2G_DEV_DCAN_CAN_CLK + 1 },
+	{ .dev = K2G_DEV_DCAN1, .num_clks = K2G_DEV_DCAN_CAN_CLK + 1 },
+	{ .dev = K2G_DEV_EMIF0, .num_clks = K2G_DEV_EMIF_VBUSP_CLK + 1 },
+	{ .dev = K2G_DEV_MMCHS0, .num_clks = K2G_DEV_MMCHS_CLK32K + 1 },
+	{ .dev = K2G_DEV_MMCHS1, .num_clks = K2G_DEV_MMCHS_CLK32K + 1 },
+	{ .dev = K2G_DEV_GPMC0, .num_clks = K2G_DEV_GPMC_GPMC_FCLK + 1 },
+	{ .dev = K2G_DEV_ELM0, .num_clks = K2G_DEV_ELM_CLK + 1 },
+	{ .dev = K2G_DEV_SPI0, .num_clks = K2G_DEV_SPI_VBUSP_CLK + 1 },
+	{ .dev = K2G_DEV_SPI1, .num_clks = K2G_DEV_SPI_VBUSP_CLK + 1 },
+	{ .dev = K2G_DEV_SPI2, .num_clks = K2G_DEV_SPI_VBUSP_CLK + 1 },
+	{ .dev = K2G_DEV_SPI3, .num_clks = K2G_DEV_SPI_VBUSP_CLK + 1 },
+	{ .dev = K2G_DEV_ICSS0, .num_clks = K2G_DEV_ICSS_IEPCLK_CLK + 1 },
+	{ .dev = K2G_DEV_ICSS1, .num_clks = K2G_DEV_ICSS_IEPCLK_CLK + 1 },
+	{ .dev = K2G_DEV_USB0, .num_clks = K2G_DEV_USB_CLKCORE + 1 },
+	{ .dev = K2G_DEV_USB1, .num_clks = K2G_DEV_USB_CLKCORE + 1 },
+	{ .dev = K2G_DEV_NSS0, .num_clks = K2G_DEV_NSS_RMII_MHZ_50_CLK + 1 },
+	{ .dev = K2G_DEV_PCIE0, .num_clks = K2G_DEV_PCIE_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_GPIO0, .num_clks = K2G_DEV_GPIO_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_GPIO1, .num_clks = K2G_DEV_GPIO_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_TIMER64_0, .num_clks = K2G_DEV_TIMER64_TOUTH + 1 },
+	{ .dev = K2G_DEV_TIMER64_1, .num_clks = K2G_DEV_TIMER64_TOUTH + 1 },
+	{ .dev = K2G_DEV_TIMER64_2, .num_clks = K2G_DEV_TIMER64_TOUTH + 1 },
+	{ .dev = K2G_DEV_TIMER64_3, .num_clks = K2G_DEV_TIMER64_TOUTH + 1 },
+	{ .dev = K2G_DEV_TIMER64_4, .num_clks = K2G_DEV_TIMER64_TOUTH + 1 },
+	{ .dev = K2G_DEV_TIMER64_5, .num_clks = K2G_DEV_TIMER64_TOUTH + 1 },
+	{ .dev = K2G_DEV_TIMER64_6, .num_clks = K2G_DEV_TIMER64_TOUTH + 1 },
+	{ .dev = K2G_DEV_MSGMGR0, .num_clks = K2G_DEV_MSGMGR_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_BOOTCFG0, .num_clks = K2G_DEV_BOOTCFG_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_ARM_BOOTROM0, .num_clks = K2G_DEV_ARM_BOOTROM_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_DSP_BOOTROM0, .num_clks = K2G_DEV_DSP_BOOTROM_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_DEBUGSS0, .num_clks = K2G_DEV_DEBUGSS_STMXPT_CLK + 1 },
+	{ .dev = K2G_DEV_UART0, .num_clks = K2G_DEV_UART_CBA_CLK_PI + 1 },
+	{ .dev = K2G_DEV_UART1, .num_clks = K2G_DEV_UART_CBA_CLK_PI + 1 },
+	{ .dev = K2G_DEV_UART2, .num_clks = K2G_DEV_UART_CBA_CLK_PI + 1 },
+	{ .dev = K2G_DEV_EHRPWM0, .num_clks = K2G_DEV_EHRPWM_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_EHRPWM1, .num_clks = K2G_DEV_EHRPWM_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_EHRPWM2, .num_clks = K2G_DEV_EHRPWM_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_EHRPWM3, .num_clks = K2G_DEV_EHRPWM_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_EHRPWM4, .num_clks = K2G_DEV_EHRPWM_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_EHRPWM5, .num_clks = K2G_DEV_EHRPWM_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_EQEP0, .num_clks = K2G_DEV_EQEP_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_EQEP1, .num_clks = K2G_DEV_EQEP_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_EQEP2, .num_clks = K2G_DEV_EQEP_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_ECAP0, .num_clks = K2G_DEV_ECAP_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_ECAP1, .num_clks = K2G_DEV_ECAP_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_I2C0, .num_clks = K2G_DEV_I2C_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_I2C1, .num_clks = K2G_DEV_I2C_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_I2C2, .num_clks = K2G_DEV_I2C_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_EDMA0, .num_clks = K2G_DEV_EDMA_TPCC_CLK + 1 },
+	{ .dev = K2G_DEV_SEMAPHORE0, .num_clks = K2G_DEV_SEMAPHORE_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_INTC0, .num_clks = K2G_DEV_INTC_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_GIC0, .num_clks = K2G_DEV_GIC_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_QSPI0, .num_clks = K2G_DEV_QSPI_QSPI_CLK_I + 1 },
+	{ .dev = K2G_DEV_ARM_64B_COUNTER0, .num_clks = K2G_DEV_ARM_64B_COUNTER_VBUSP_CLK + 1 },
+	{ .dev = K2G_DEV_TETRIS0, .num_clks = K2G_DEV_TETRIS_SUBSYS_CLK + 1 },
+	{ .dev = K2G_DEV_CGEM0, .num_clks = K2G_DEV_CGEM_TRACE_CLK + 1 },
+	{ .dev = K2G_DEV_MSMC0, .num_clks = K2G_DEV_MSMC_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_CBASS0, .num_clks = K2G_DEV_CBASS_VBUS_CLK + 1 },
+	{ .dev = K2G_DEV_BOARD0, .num_clks = K2G_DEV_BOARD_TIMO_PARENT_TIMER64_5H + 1 },
+	{ .dev = K2G_DEV_EDMA1, .num_clks = K2G_DEV_EDMA_TPCC_CLK + 1 },
+	{ .num_clks = 0 },
+};
+
+static const struct of_device_id ti_sci_clk_of_match[] = {
+	{ .compatible = "ti,k2g-sci-clk", .data = &k2g_clk_data },
+	{ /* Sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, ti_sci_clk_of_match);
+
+/**
+ * ti_sci_clk_probe - Probe function for the TI SCI clock driver
+ * @pdev: platform device pointer to be probed
+ *
+ * Probes the TI SCI clock device. Allocates a new clock provider
+ * and registers this to the common clock framework. Also applies
+ * any required flags to the identified clocks via clock lists
+ * supplied from DT. Returns 0 for success, negative error value
+ * for failure.
+ */
+static int ti_sci_clk_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct sci_clk_provider *provider;
+	const struct ti_sci_handle *handle;
+	struct sci_clk_data *data;
+	int ret;
+
+	data = (struct sci_clk_data *)
+		of_match_node(ti_sci_clk_of_match, np)->data;
+
+	handle = devm_ti_sci_get_handle(dev);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+
+	provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL);
+	if (!provider)
+		return -ENOMEM;
+
+	provider->clocks = data;
+
+	provider->sci = handle;
+	provider->ops = &handle->ops.clk_ops;
+	provider->dev = dev;
+
+	ti_sci_init_clocks(provider);
+
+	ret = of_clk_add_hw_provider(np, sci_clk_get, provider);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/**
+ * ti_sci_clk_remove - Remove TI SCI clock device
+ * @pdev: platform device pointer for the device to be removed
+ *
+ * Removes the TI SCI device. Unregisters the clock provider registered
+ * via common clock framework. Any memory allocated for the device will
+ * be free'd silently via the devm framework. Returns 0 always.
+ */
+static int ti_sci_clk_remove(struct platform_device *pdev)
+{
+	of_clk_del_provider(pdev->dev.of_node);
+
+	return 0;
+}
+
+static struct platform_driver ti_sci_clk_driver = {
+	.probe = ti_sci_clk_probe,
+	.remove = ti_sci_clk_remove,
+	.driver = {
+		.name = "ti-sci-clk",
+		.of_match_table = of_match_ptr(ti_sci_clk_of_match),
+	},
+};
+module_platform_driver(ti_sci_clk_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("TI System Control Interface(SCI) Clock driver");
+MODULE_AUTHOR("Tero Kristo");
+MODULE_ALIAS("platform:ti-sci-clk");