diff mbox

[6/7] mfd: exynos-lpass: Add support for clocks

Message ID 1485345031-2948-7-git-send-email-m.szyprowski@samsung.com (mailing list archive)
State Superseded
Headers show

Commit Message

Marek Szyprowski Jan. 25, 2017, 11:50 a.m. UTC
Exynos LPASS requires some clocks to be enabled to make any access to its
registers. This patch adds code for handling such clocks. For current set
of registers it is enough to keep sfr0_ctrl clock enabled. Till now it
worked only because those clocks were enabled by bootloader and driver
probe() happened before they were disabled by clock core because of lack
of users. Handling those clocks is also needed to make it possible to
enable support for audio power domain.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 .../devicetree/bindings/mfd/samsung,exynos5433-lpass.txt       |  6 ++++++
 drivers/mfd/exynos-lpass.c                                     | 10 ++++++++++
 2 files changed, 16 insertions(+)

Comments

Krzysztof Kozlowski Jan. 25, 2017, 8 p.m. UTC | #1
On Wed, Jan 25, 2017 at 12:50:30PM +0100, Marek Szyprowski wrote:
> Exynos LPASS requires some clocks to be enabled to make any access to its
> registers. This patch adds code for handling such clocks. For current set
> of registers it is enough to keep sfr0_ctrl clock enabled. Till now it
> worked only because those clocks were enabled by bootloader and driver
> probe() happened before they were disabled by clock core because of lack
> of users. Handling those clocks is also needed to make it possible to
> enable support for audio power domain.
> 
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>  .../devicetree/bindings/mfd/samsung,exynos5433-lpass.txt       |  6 ++++++
>  drivers/mfd/exynos-lpass.c                                     | 10 ++++++++++
>  2 files changed, 16 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mfd/samsung,exynos5433-lpass.txt b/Documentation/devicetree/bindings/mfd/samsung,exynos5433-lpass.txt
> index a8deaee82c44..df664018c148 100644
> --- a/Documentation/devicetree/bindings/mfd/samsung,exynos5433-lpass.txt
> +++ b/Documentation/devicetree/bindings/mfd/samsung,exynos5433-lpass.txt
> @@ -5,6 +5,10 @@ Required properties:
>   - compatible		: "samsung,exynos5433-lpass"
>   - reg			: should contain the LPASS top SFR region location
>  			  and size
> + - clock-names		: should contain following required clocks: "sfr0_ctrl"
> + - clocks		: should contain clock specifiers of all clocks, which
> +			  input names have been specified in clock-names
> +			  property, in same order.
>   - #address-cells	: should be 1
>   - #size-cells		: should be 1
>   - ranges		: must be present
> @@ -24,6 +28,8 @@ Example:
>  audio-subsystem {
>  	compatible = "samsung,exynos5433-lpass";
>  	reg = <0x11400000 0x100>, <0x11500000 0x08>;
> +	clocks = <&cmu_aud CLK_PCLK_SFR0_CTRL>;
> +	clock-names = "sfr0_ctrl";
>  	#address-cells = <1>;
>  	#size-cells = <1>;
>  	ranges;
> diff --git a/drivers/mfd/exynos-lpass.c b/drivers/mfd/exynos-lpass.c
> index 17915daa2e80..44d8ea1a978b 100644
> --- a/drivers/mfd/exynos-lpass.c
> +++ b/drivers/mfd/exynos-lpass.c
> @@ -14,6 +14,7 @@
>   * only version 2 as published by the Free Software Foundation.
>   */
>  
> +#include <linux/clk.h>
>  #include <linux/delay.h>
>  #include <linux/io.h>
>  #include <linux/module.h>
> @@ -52,6 +53,7 @@
>  struct exynos_lpass {
>  	/* pointer to the LPASS TOP regmap */
>  	struct regmap *top;
> +	struct clk *sfr0_clk;
>  };
>  
>  static void exynos_lpass_core_sw_reset(struct exynos_lpass *lpass, int mask)
> @@ -71,6 +73,8 @@ static void exynos_lpass_core_sw_reset(struct exynos_lpass *lpass, int mask)
>  
>  static void exynos_lpass_enable(struct exynos_lpass *lpass)
>  {
> +	clk_prepare_enable(lpass->sfr0_clk);
> +
>  	/* Unmask SFR, DMA and I2S interrupt */
>  	regmap_write(lpass->top, SFR_LPASS_INTR_CA5_MASK,
>  		     LPASS_INTR_SFR | LPASS_INTR_DMA | LPASS_INTR_I2S);
> @@ -88,6 +92,8 @@ static void exynos_lpass_disable(struct exynos_lpass *lpass)
>  	/* Mask any unmasked IP interrupt sources */
>  	regmap_write(lpass->top, SFR_LPASS_INTR_CPU_MASK, 0);
>  	regmap_write(lpass->top, SFR_LPASS_INTR_CA5_MASK, 0);
> +
> +	clk_disable_unprepare(lpass->sfr0_clk);
>  }
>  
>  static const struct regmap_config exynos_lpass_reg_conf = {
> @@ -114,6 +120,10 @@ static int exynos_lpass_probe(struct platform_device *pdev)
>  	if (IS_ERR(base_top))
>  		return PTR_ERR(base_top);
>  
> +	lpass->sfr0_clk = clk_get(dev, "sfr0_ctrl");
> +	if (IS_ERR(lpass->sfr0_clk))
> +		return PTR_ERR(lpass->sfr0_clk);

devm_clk_get() or implement the remove() or the unbind should be
suppressed.

Not related to this particular patch, but:
1. regmap_exit() is also missing (anyone would like to add it?),
2. Also I wonder, whether we would like to disable the LPASS on
   unbind...

Best regards,
Krzysztof
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Krzysztof Kozlowski Jan. 25, 2017, 8:02 p.m. UTC | #2
On Wed, Jan 25, 2017 at 10:00:06PM +0200, Krzysztof Kozlowski wrote:
> On Wed, Jan 25, 2017 at 12:50:30PM +0100, Marek Szyprowski wrote:
> > Exynos LPASS requires some clocks to be enabled to make any access to its
> > registers. This patch adds code for handling such clocks. For current set
> > of registers it is enough to keep sfr0_ctrl clock enabled. Till now it
> > worked only because those clocks were enabled by bootloader and driver
> > probe() happened before they were disabled by clock core because of lack
> > of users. Handling those clocks is also needed to make it possible to
> > enable support for audio power domain.
> > 
> > Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> > ---
> >  .../devicetree/bindings/mfd/samsung,exynos5433-lpass.txt       |  6 ++++++
> >  drivers/mfd/exynos-lpass.c                                     | 10 ++++++++++
> >  2 files changed, 16 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/mfd/samsung,exynos5433-lpass.txt b/Documentation/devicetree/bindings/mfd/samsung,exynos5433-lpass.txt
> > index a8deaee82c44..df664018c148 100644
> > --- a/Documentation/devicetree/bindings/mfd/samsung,exynos5433-lpass.txt
> > +++ b/Documentation/devicetree/bindings/mfd/samsung,exynos5433-lpass.txt
> > @@ -5,6 +5,10 @@ Required properties:
> >   - compatible		: "samsung,exynos5433-lpass"
> >   - reg			: should contain the LPASS top SFR region location
> >  			  and size
> > + - clock-names		: should contain following required clocks: "sfr0_ctrl"
> > + - clocks		: should contain clock specifiers of all clocks, which
> > +			  input names have been specified in clock-names
> > +			  property, in same order.
> >   - #address-cells	: should be 1
> >   - #size-cells		: should be 1
> >   - ranges		: must be present
> > @@ -24,6 +28,8 @@ Example:
> >  audio-subsystem {
> >  	compatible = "samsung,exynos5433-lpass";
> >  	reg = <0x11400000 0x100>, <0x11500000 0x08>;
> > +	clocks = <&cmu_aud CLK_PCLK_SFR0_CTRL>;
> > +	clock-names = "sfr0_ctrl";
> >  	#address-cells = <1>;
> >  	#size-cells = <1>;
> >  	ranges;
> > diff --git a/drivers/mfd/exynos-lpass.c b/drivers/mfd/exynos-lpass.c
> > index 17915daa2e80..44d8ea1a978b 100644
> > --- a/drivers/mfd/exynos-lpass.c
> > +++ b/drivers/mfd/exynos-lpass.c
> > @@ -14,6 +14,7 @@
> >   * only version 2 as published by the Free Software Foundation.
> >   */
> >  
> > +#include <linux/clk.h>
> >  #include <linux/delay.h>
> >  #include <linux/io.h>
> >  #include <linux/module.h>
> > @@ -52,6 +53,7 @@
> >  struct exynos_lpass {
> >  	/* pointer to the LPASS TOP regmap */
> >  	struct regmap *top;
> > +	struct clk *sfr0_clk;
> >  };
> >  
> >  static void exynos_lpass_core_sw_reset(struct exynos_lpass *lpass, int mask)
> > @@ -71,6 +73,8 @@ static void exynos_lpass_core_sw_reset(struct exynos_lpass *lpass, int mask)
> >  
> >  static void exynos_lpass_enable(struct exynos_lpass *lpass)
> >  {
> > +	clk_prepare_enable(lpass->sfr0_clk);
> > +
> >  	/* Unmask SFR, DMA and I2S interrupt */
> >  	regmap_write(lpass->top, SFR_LPASS_INTR_CA5_MASK,
> >  		     LPASS_INTR_SFR | LPASS_INTR_DMA | LPASS_INTR_I2S);
> > @@ -88,6 +92,8 @@ static void exynos_lpass_disable(struct exynos_lpass *lpass)
> >  	/* Mask any unmasked IP interrupt sources */
> >  	regmap_write(lpass->top, SFR_LPASS_INTR_CPU_MASK, 0);
> >  	regmap_write(lpass->top, SFR_LPASS_INTR_CA5_MASK, 0);
> > +
> > +	clk_disable_unprepare(lpass->sfr0_clk);
> >  }
> >  
> >  static const struct regmap_config exynos_lpass_reg_conf = {
> > @@ -114,6 +120,10 @@ static int exynos_lpass_probe(struct platform_device *pdev)
> >  	if (IS_ERR(base_top))
> >  		return PTR_ERR(base_top);
> >  
> > +	lpass->sfr0_clk = clk_get(dev, "sfr0_ctrl");
> > +	if (IS_ERR(lpass->sfr0_clk))
> > +		return PTR_ERR(lpass->sfr0_clk);
> 
> devm_clk_get() or implement the remove() or the unbind should be
> suppressed.
> 
> Not related to this particular patch, but:
> 1. regmap_exit() is also missing (anyone would like to add it?),
> 2. Also I wonder, whether we would like to disable the LPASS on
>    unbind...

I forgot about one thing - please mention in the commit message that
this breaks the ABI or requires changes in DTS to provide the clock.

Best regards,
Krzysztof
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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/mfd/samsung,exynos5433-lpass.txt b/Documentation/devicetree/bindings/mfd/samsung,exynos5433-lpass.txt
index a8deaee82c44..df664018c148 100644
--- a/Documentation/devicetree/bindings/mfd/samsung,exynos5433-lpass.txt
+++ b/Documentation/devicetree/bindings/mfd/samsung,exynos5433-lpass.txt
@@ -5,6 +5,10 @@  Required properties:
  - compatible		: "samsung,exynos5433-lpass"
  - reg			: should contain the LPASS top SFR region location
 			  and size
+ - clock-names		: should contain following required clocks: "sfr0_ctrl"
+ - clocks		: should contain clock specifiers of all clocks, which
+			  input names have been specified in clock-names
+			  property, in same order.
  - #address-cells	: should be 1
  - #size-cells		: should be 1
  - ranges		: must be present
@@ -24,6 +28,8 @@  Example:
 audio-subsystem {
 	compatible = "samsung,exynos5433-lpass";
 	reg = <0x11400000 0x100>, <0x11500000 0x08>;
+	clocks = <&cmu_aud CLK_PCLK_SFR0_CTRL>;
+	clock-names = "sfr0_ctrl";
 	#address-cells = <1>;
 	#size-cells = <1>;
 	ranges;
diff --git a/drivers/mfd/exynos-lpass.c b/drivers/mfd/exynos-lpass.c
index 17915daa2e80..44d8ea1a978b 100644
--- a/drivers/mfd/exynos-lpass.c
+++ b/drivers/mfd/exynos-lpass.c
@@ -14,6 +14,7 @@ 
  * only version 2 as published by the Free Software Foundation.
  */
 
+#include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/module.h>
@@ -52,6 +53,7 @@ 
 struct exynos_lpass {
 	/* pointer to the LPASS TOP regmap */
 	struct regmap *top;
+	struct clk *sfr0_clk;
 };
 
 static void exynos_lpass_core_sw_reset(struct exynos_lpass *lpass, int mask)
@@ -71,6 +73,8 @@  static void exynos_lpass_core_sw_reset(struct exynos_lpass *lpass, int mask)
 
 static void exynos_lpass_enable(struct exynos_lpass *lpass)
 {
+	clk_prepare_enable(lpass->sfr0_clk);
+
 	/* Unmask SFR, DMA and I2S interrupt */
 	regmap_write(lpass->top, SFR_LPASS_INTR_CA5_MASK,
 		     LPASS_INTR_SFR | LPASS_INTR_DMA | LPASS_INTR_I2S);
@@ -88,6 +92,8 @@  static void exynos_lpass_disable(struct exynos_lpass *lpass)
 	/* Mask any unmasked IP interrupt sources */
 	regmap_write(lpass->top, SFR_LPASS_INTR_CPU_MASK, 0);
 	regmap_write(lpass->top, SFR_LPASS_INTR_CA5_MASK, 0);
+
+	clk_disable_unprepare(lpass->sfr0_clk);
 }
 
 static const struct regmap_config exynos_lpass_reg_conf = {
@@ -114,6 +120,10 @@  static int exynos_lpass_probe(struct platform_device *pdev)
 	if (IS_ERR(base_top))
 		return PTR_ERR(base_top);
 
+	lpass->sfr0_clk = clk_get(dev, "sfr0_ctrl");
+	if (IS_ERR(lpass->sfr0_clk))
+		return PTR_ERR(lpass->sfr0_clk);
+
 	lpass->top = regmap_init_mmio(dev, base_top,
 					&exynos_lpass_reg_conf);
 	if (IS_ERR(lpass->top)) {