In certain boards the source for the clk32k clock can be gated. In these
boards the clk32k clock can be provided to the driver and it is going to be
enabled/disabled when it is needed.
If the clk32k clock is not provided the driver will assume that it is always
running.
Signed-off-by: Peter Ujfalusi <[email protected]>
---
Documentation/devicetree/bindings/mfd/twl6040.txt | 2 ++
drivers/mfd/twl6040.c | 10 ++++++++++
include/linux/mfd/twl6040.h | 2 ++
3 files changed, 14 insertions(+)
diff --git a/Documentation/devicetree/bindings/mfd/twl6040.txt b/Documentation/devicetree/bindings/mfd/twl6040.txt
index 0f5dd709d752..a41157b5d930 100644
--- a/Documentation/devicetree/bindings/mfd/twl6040.txt
+++ b/Documentation/devicetree/bindings/mfd/twl6040.txt
@@ -19,6 +19,8 @@ Required properties:
Optional properties, nodes:
- enable-active-high: To power on the twl6040 during boot.
+- clocks: phandle to the clk32k clock provider
+- clock-names: Must be "clk32k"
Vibra functionality
Required properties:
diff --git a/drivers/mfd/twl6040.c b/drivers/mfd/twl6040.c
index 2e6504a8e1e3..12b314ea48dc 100644
--- a/drivers/mfd/twl6040.c
+++ b/drivers/mfd/twl6040.c
@@ -291,6 +291,8 @@ int twl6040_power(struct twl6040 *twl6040, int on)
if (twl6040->power_count++)
goto out;
+ clk_prepare_enable(twl6040->clk32k);
+
/* Allow writes to the chip */
regcache_cache_only(twl6040->regmap, false);
@@ -346,6 +348,8 @@ int twl6040_power(struct twl6040 *twl6040, int on)
twl6040->sysclk = 0;
twl6040->mclk = 0;
+
+ clk_disable_unprepare(twl6040->clk32k);
}
out:
@@ -644,6 +648,12 @@ static int twl6040_probe(struct i2c_client *client,
i2c_set_clientdata(client, twl6040);
+ twl6040->clk32k = devm_clk_get(&client->dev, "clk32k");
+ if (IS_ERR(twl6040->clk32k)) {
+ dev_info(&client->dev, "clk32k is not handled\n");
+ twl6040->clk32k = NULL;
+ }
+
twl6040->supplies[0].supply = "vio";
twl6040->supplies[1].supply = "v2v1";
ret = devm_regulator_bulk_get(&client->dev, TWL6040_NUM_SUPPLIES,
diff --git a/include/linux/mfd/twl6040.h b/include/linux/mfd/twl6040.h
index a69d16b30c18..8f9fc3d26e6d 100644
--- a/include/linux/mfd/twl6040.h
+++ b/include/linux/mfd/twl6040.h
@@ -28,6 +28,7 @@
#include <linux/interrupt.h>
#include <linux/mfd/core.h>
#include <linux/regulator/consumer.h>
+#include <linux/clk.h>
#define TWL6040_REG_ASICID 0x01
#define TWL6040_REG_ASICREV 0x02
@@ -223,6 +224,7 @@ struct twl6040 {
struct regmap *regmap;
struct regmap_irq_chip_data *irq_data;
struct regulator_bulk_data supplies[2]; /* supplies for vio, v2v1 */
+ struct clk *clk32k;
struct mutex mutex;
struct mutex irq_mutex;
struct mfd_cell cells[TWL6040_CELLS];
--
1.9.1
In certain boards the source for the clk32k clock can be gated. In these
boards the clk32k clock can be provided to the driver and it is going to be
enabled/disabled when it is needed.
If the clk32k clock is not provided the driver will assume that it is always
running.
Signed-off-by: Peter Ujfalusi <[email protected]>
---
Documentation/devicetree/bindings/mfd/twl6040.txt | 2 ++
drivers/mfd/twl6040.c | 10 ++++++++++
include/linux/mfd/twl6040.h | 2 ++
3 files changed, 14 insertions(+)
diff --git a/Documentation/devicetree/bindings/mfd/twl6040.txt b/Documentation/devicetree/bindings/mfd/twl6040.txt
index 0f5dd709d752..a41157b5d930 100644
--- a/Documentation/devicetree/bindings/mfd/twl6040.txt
+++ b/Documentation/devicetree/bindings/mfd/twl6040.txt
@@ -19,6 +19,8 @@ Required properties:
Optional properties, nodes:
- enable-active-high: To power on the twl6040 during boot.
+- clocks: phandle to the clk32k clock provider
+- clock-names: Must be "clk32k"
Vibra functionality
Required properties:
diff --git a/drivers/mfd/twl6040.c b/drivers/mfd/twl6040.c
index 2e6504a8e1e3..12b314ea48dc 100644
--- a/drivers/mfd/twl6040.c
+++ b/drivers/mfd/twl6040.c
@@ -291,6 +291,8 @@ int twl6040_power(struct twl6040 *twl6040, int on)
if (twl6040->power_count++)
goto out;
+ clk_prepare_enable(twl6040->clk32k);
+
/* Allow writes to the chip */
regcache_cache_only(twl6040->regmap, false);
@@ -346,6 +348,8 @@ int twl6040_power(struct twl6040 *twl6040, int on)
twl6040->sysclk = 0;
twl6040->mclk = 0;
+
+ clk_disable_unprepare(twl6040->clk32k);
}
out:
@@ -644,6 +648,12 @@ static int twl6040_probe(struct i2c_client *client,
i2c_set_clientdata(client, twl6040);
+ twl6040->clk32k = devm_clk_get(&client->dev, "clk32k");
+ if (IS_ERR(twl6040->clk32k)) {
+ dev_info(&client->dev, "clk32k is not handled\n");
+ twl6040->clk32k = NULL;
+ }
+
twl6040->supplies[0].supply = "vio";
twl6040->supplies[1].supply = "v2v1";
ret = devm_regulator_bulk_get(&client->dev, TWL6040_NUM_SUPPLIES,
diff --git a/include/linux/mfd/twl6040.h b/include/linux/mfd/twl6040.h
index a69d16b30c18..8f9fc3d26e6d 100644
--- a/include/linux/mfd/twl6040.h
+++ b/include/linux/mfd/twl6040.h
@@ -28,6 +28,7 @@
#include <linux/interrupt.h>
#include <linux/mfd/core.h>
#include <linux/regulator/consumer.h>
+#include <linux/clk.h>
#define TWL6040_REG_ASICID 0x01
#define TWL6040_REG_ASICREV 0x02
@@ -223,6 +224,7 @@ struct twl6040 {
struct regmap *regmap;
struct regmap_irq_chip_data *irq_data;
struct regulator_bulk_data supplies[2]; /* supplies for vio, v2v1 */
+ struct clk *clk32k;
struct mutex mutex;
struct mutex irq_mutex;
struct mfd_cell cells[TWL6040_CELLS];
--
1.9.1
Lee,
On 04/03/2014 01:54 PM, Peter Ujfalusi wrote:
> In certain boards the source for the clk32k clock can be gated. In these
> boards the clk32k clock can be provided to the driver and it is going to be
> enabled/disabled when it is needed.
> If the clk32k clock is not provided the driver will assume that it is always
> running.
Do you want me to resend this patch, it seams to be missing from next still.
Thanks,
P?ter
>
> Signed-off-by: Peter Ujfalusi <[email protected]>
> ---
> Documentation/devicetree/bindings/mfd/twl6040.txt | 2 ++
> drivers/mfd/twl6040.c | 10 ++++++++++
> include/linux/mfd/twl6040.h | 2 ++
> 3 files changed, 14 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/mfd/twl6040.txt b/Documentation/devicetree/bindings/mfd/twl6040.txt
> index 0f5dd709d752..a41157b5d930 100644
> --- a/Documentation/devicetree/bindings/mfd/twl6040.txt
> +++ b/Documentation/devicetree/bindings/mfd/twl6040.txt
> @@ -19,6 +19,8 @@ Required properties:
>
> Optional properties, nodes:
> - enable-active-high: To power on the twl6040 during boot.
> +- clocks: phandle to the clk32k clock provider
> +- clock-names: Must be "clk32k"
>
> Vibra functionality
> Required properties:
> diff --git a/drivers/mfd/twl6040.c b/drivers/mfd/twl6040.c
> index 2e6504a8e1e3..12b314ea48dc 100644
> --- a/drivers/mfd/twl6040.c
> +++ b/drivers/mfd/twl6040.c
> @@ -291,6 +291,8 @@ int twl6040_power(struct twl6040 *twl6040, int on)
> if (twl6040->power_count++)
> goto out;
>
> + clk_prepare_enable(twl6040->clk32k);
> +
> /* Allow writes to the chip */
> regcache_cache_only(twl6040->regmap, false);
>
> @@ -346,6 +348,8 @@ int twl6040_power(struct twl6040 *twl6040, int on)
>
> twl6040->sysclk = 0;
> twl6040->mclk = 0;
> +
> + clk_disable_unprepare(twl6040->clk32k);
> }
>
> out:
> @@ -644,6 +648,12 @@ static int twl6040_probe(struct i2c_client *client,
>
> i2c_set_clientdata(client, twl6040);
>
> + twl6040->clk32k = devm_clk_get(&client->dev, "clk32k");
> + if (IS_ERR(twl6040->clk32k)) {
> + dev_info(&client->dev, "clk32k is not handled\n");
> + twl6040->clk32k = NULL;
> + }
> +
> twl6040->supplies[0].supply = "vio";
> twl6040->supplies[1].supply = "v2v1";
> ret = devm_regulator_bulk_get(&client->dev, TWL6040_NUM_SUPPLIES,
> diff --git a/include/linux/mfd/twl6040.h b/include/linux/mfd/twl6040.h
> index a69d16b30c18..8f9fc3d26e6d 100644
> --- a/include/linux/mfd/twl6040.h
> +++ b/include/linux/mfd/twl6040.h
> @@ -28,6 +28,7 @@
> #include <linux/interrupt.h>
> #include <linux/mfd/core.h>
> #include <linux/regulator/consumer.h>
> +#include <linux/clk.h>
>
> #define TWL6040_REG_ASICID 0x01
> #define TWL6040_REG_ASICREV 0x02
> @@ -223,6 +224,7 @@ struct twl6040 {
> struct regmap *regmap;
> struct regmap_irq_chip_data *irq_data;
> struct regulator_bulk_data supplies[2]; /* supplies for vio, v2v1 */
> + struct clk *clk32k;
> struct mutex mutex;
> struct mutex irq_mutex;
> struct mfd_cell cells[TWL6040_CELLS];
>
> In certain boards the source for the clk32k clock can be gated. In these
> boards the clk32k clock can be provided to the driver and it is going to be
> enabled/disabled when it is needed.
> If the clk32k clock is not provided the driver will assume that it is always
> running.
>
> Signed-off-by: Peter Ujfalusi <[email protected]>
> ---
> Documentation/devicetree/bindings/mfd/twl6040.txt | 2 ++
> drivers/mfd/twl6040.c | 10 ++++++++++
> include/linux/mfd/twl6040.h | 2 ++
> 3 files changed, 14 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/mfd/twl6040.txt b/Documentation/devicetree/bindings/mfd/twl6040.txt
> index 0f5dd709d752..a41157b5d930 100644
> --- a/Documentation/devicetree/bindings/mfd/twl6040.txt
> +++ b/Documentation/devicetree/bindings/mfd/twl6040.txt
> @@ -19,6 +19,8 @@ Required properties:
>
> Optional properties, nodes:
> - enable-active-high: To power on the twl6040 during boot.
> +- clocks: phandle to the clk32k clock provider
> +- clock-names: Must be "clk32k"
>
> Vibra functionality
> Required properties:
> diff --git a/drivers/mfd/twl6040.c b/drivers/mfd/twl6040.c
> index 2e6504a8e1e3..12b314ea48dc 100644
> --- a/drivers/mfd/twl6040.c
> +++ b/drivers/mfd/twl6040.c
> @@ -291,6 +291,8 @@ int twl6040_power(struct twl6040 *twl6040, int on)
> if (twl6040->power_count++)
> goto out;
>
> + clk_prepare_enable(twl6040->clk32k);
> +
> /* Allow writes to the chip */
> regcache_cache_only(twl6040->regmap, false);
>
> @@ -346,6 +348,8 @@ int twl6040_power(struct twl6040 *twl6040, int on)
>
> twl6040->sysclk = 0;
> twl6040->mclk = 0;
> +
> + clk_disable_unprepare(twl6040->clk32k);
> }
>
> out:
> @@ -644,6 +648,12 @@ static int twl6040_probe(struct i2c_client *client,
>
> i2c_set_clientdata(client, twl6040);
>
> + twl6040->clk32k = devm_clk_get(&client->dev, "clk32k");
> + if (IS_ERR(twl6040->clk32k)) {
> + dev_info(&client->dev, "clk32k is not handled\n");
> + twl6040->clk32k = NULL;
So what happens if you pass a NULL clk reference to clk_prepare_enable()?
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
On 04/28/2014 01:36 PM, Lee Jones wrote:
>> In certain boards the source for the clk32k clock can be gated. In these
>> boards the clk32k clock can be provided to the driver and it is going to be
>> enabled/disabled when it is needed.
>> If the clk32k clock is not provided the driver will assume that it is always
>> running.
>>
>> Signed-off-by: Peter Ujfalusi <[email protected]>
>> ---
>> Documentation/devicetree/bindings/mfd/twl6040.txt | 2 ++
>> drivers/mfd/twl6040.c | 10 ++++++++++
>> include/linux/mfd/twl6040.h | 2 ++
>> 3 files changed, 14 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/mfd/twl6040.txt b/Documentation/devicetree/bindings/mfd/twl6040.txt
>> index 0f5dd709d752..a41157b5d930 100644
>> --- a/Documentation/devicetree/bindings/mfd/twl6040.txt
>> +++ b/Documentation/devicetree/bindings/mfd/twl6040.txt
>> @@ -19,6 +19,8 @@ Required properties:
>>
>> Optional properties, nodes:
>> - enable-active-high: To power on the twl6040 during boot.
>> +- clocks: phandle to the clk32k clock provider
>> +- clock-names: Must be "clk32k"
>>
>> Vibra functionality
>> Required properties:
>> diff --git a/drivers/mfd/twl6040.c b/drivers/mfd/twl6040.c
>> index 2e6504a8e1e3..12b314ea48dc 100644
>> --- a/drivers/mfd/twl6040.c
>> +++ b/drivers/mfd/twl6040.c
>> @@ -291,6 +291,8 @@ int twl6040_power(struct twl6040 *twl6040, int on)
>> if (twl6040->power_count++)
>> goto out;
>>
>> + clk_prepare_enable(twl6040->clk32k);
>> +
>> /* Allow writes to the chip */
>> regcache_cache_only(twl6040->regmap, false);
>>
>> @@ -346,6 +348,8 @@ int twl6040_power(struct twl6040 *twl6040, int on)
>>
>> twl6040->sysclk = 0;
>> twl6040->mclk = 0;
>> +
>> + clk_disable_unprepare(twl6040->clk32k);
>> }
>>
>> out:
>> @@ -644,6 +648,12 @@ static int twl6040_probe(struct i2c_client *client,
>>
>> i2c_set_clientdata(client, twl6040);
>>
>> + twl6040->clk32k = devm_clk_get(&client->dev, "clk32k");
>> + if (IS_ERR(twl6040->clk32k)) {
>> + dev_info(&client->dev, "clk32k is not handled\n");
>> + twl6040->clk32k = NULL;
>
> So what happens if you pass a NULL clk reference to clk_prepare_enable()?
We have checks for !clk in all cases within the clk_* API. If we pass NULL,
nothing will happen and from the calling driver point of view it will look
like a success.
AFAIK this is the way to handle non esential/optional clocks without if()s in
the driver code around the clock handling.
--
Péter
On Mon, 28 Apr 2014, Peter Ujfalusi wrote:
> On 04/28/2014 01:36 PM, Lee Jones wrote:
> >> In certain boards the source for the clk32k clock can be gated. In these
> >> boards the clk32k clock can be provided to the driver and it is going to be
> >> enabled/disabled when it is needed.
> >> If the clk32k clock is not provided the driver will assume that it is always
> >> running.
> >>
> >> Signed-off-by: Peter Ujfalusi <[email protected]>
> >> ---
> >> Documentation/devicetree/bindings/mfd/twl6040.txt | 2 ++
> >> drivers/mfd/twl6040.c | 10 ++++++++++
> >> include/linux/mfd/twl6040.h | 2 ++
> >> 3 files changed, 14 insertions(+)
> >>
> >> diff --git a/Documentation/devicetree/bindings/mfd/twl6040.txt b/Documentation/devicetree/bindings/mfd/twl6040.txt
> >> index 0f5dd709d752..a41157b5d930 100644
> >> --- a/Documentation/devicetree/bindings/mfd/twl6040.txt
> >> +++ b/Documentation/devicetree/bindings/mfd/twl6040.txt
> >> @@ -19,6 +19,8 @@ Required properties:
> >>
> >> Optional properties, nodes:
> >> - enable-active-high: To power on the twl6040 during boot.
> >> +- clocks: phandle to the clk32k clock provider
> >> +- clock-names: Must be "clk32k"
> >>
> >> Vibra functionality
> >> Required properties:
> >> diff --git a/drivers/mfd/twl6040.c b/drivers/mfd/twl6040.c
> >> index 2e6504a8e1e3..12b314ea48dc 100644
> >> --- a/drivers/mfd/twl6040.c
> >> +++ b/drivers/mfd/twl6040.c
> >> @@ -291,6 +291,8 @@ int twl6040_power(struct twl6040 *twl6040, int on)
> >> if (twl6040->power_count++)
> >> goto out;
> >>
> >> + clk_prepare_enable(twl6040->clk32k);
> >> +
> >> /* Allow writes to the chip */
> >> regcache_cache_only(twl6040->regmap, false);
> >>
> >> @@ -346,6 +348,8 @@ int twl6040_power(struct twl6040 *twl6040, int on)
> >>
> >> twl6040->sysclk = 0;
> >> twl6040->mclk = 0;
> >> +
> >> + clk_disable_unprepare(twl6040->clk32k);
> >> }
> >>
> >> out:
> >> @@ -644,6 +648,12 @@ static int twl6040_probe(struct i2c_client *client,
> >>
> >> i2c_set_clientdata(client, twl6040);
> >>
> >> + twl6040->clk32k = devm_clk_get(&client->dev, "clk32k");
> >> + if (IS_ERR(twl6040->clk32k)) {
> >> + dev_info(&client->dev, "clk32k is not handled\n");
> >> + twl6040->clk32k = NULL;
> >
> > So what happens if you pass a NULL clk reference to clk_prepare_enable()?
>
> We have checks for !clk in all cases within the clk_* API. If we pass NULL,
> nothing will happen and from the calling driver point of view it will look
> like a success.
> AFAIK this is the way to handle non esential/optional clocks without if()s in
> the driver code around the clock handling.
Okay, so long as those checks are there, we're all good.
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
> In certain boards the source for the clk32k clock can be gated. In these
> boards the clk32k clock can be provided to the driver and it is going to be
> enabled/disabled when it is needed.
> If the clk32k clock is not provided the driver will assume that it is always
> running.
>
> Signed-off-by: Peter Ujfalusi <[email protected]>
> ---
> Documentation/devicetree/bindings/mfd/twl6040.txt | 2 ++
> drivers/mfd/twl6040.c | 10 ++++++++++
> include/linux/mfd/twl6040.h | 2 ++
> 3 files changed, 14 insertions(+)
Applied, thanks.
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog