[PATCH 0/2] Add code to manage DSP related clocks

[PATCH 0/2] Add code to manage DSP related clocks

[Daniel Baluta]

From: Daniel Baluta <daniel.baluta@nxp.com>

DSP node on the Linux kernel side must also take care of enabling
DAI/DMA related clocks.

By design we choose to manage DAI/DMA clocks from the kernel side
because of the architecture of some i.MX8 boards.

Clocks are handled by a special M4 core which runs a special
firmware called SCFW (System Controler firmware).

This communicates with A cores running Linux via a special Messaging
Unit and implements a custom API which is already implemented by the
Linux kernel i.MX clocks implementation.

Note that these clocks are optional. We can use the DSP without
them.

First patch was already sent to review on SOF Github:
https://github.com/thesofproject/linux/pull/3131

Daniel Baluta (2):
  ASoC: SOF: imx: Add code to manage DSP related clocks
  dt-bindings: dsp: fsl: Add DSP optional clocks documentation

 .../devicetree/bindings/dsp/fsl,dsp.yaml      | 33 ++++++++
 sound/soc/sof/imx/imx-common.c                | 77 +++++++++++++++++++
 sound/soc/sof/imx/imx-common.h                | 16 ++++
 sound/soc/sof/imx/imx8.c                      | 32 ++++++++
 sound/soc/sof/imx/imx8m.c                     | 33 ++++++++
 5 files changed, 191 insertions(+)

-- 
2.27.0

[PATCH 1/2] ASoC: SOF: imx: Add code to manage DSP related clocks

[Daniel Baluta]

From: Daniel Baluta <daniel.baluta@nxp.com>

There are two types of clocks:
	* DSP IP clocks
	* DAI clocks

This clocks are necessary in order to power up DSP and DAIs.

We choose to enable DAI clocks here because of the way i.MX8/i.MX8X
design handles resources (including clocks).

All clocks are managed by a separate core (named SCU) which communicates
with Linux managed ARM core via a well known API.

We parse and enable the clocks in probe function and disable them in
remove function.

Future patches will introduce Power Management support so that we
disable clocks while DSP is not used or system enters power save.

Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
---
 sound/soc/sof/imx/imx-common.c | 77 ++++++++++++++++++++++++++++++++++
 sound/soc/sof/imx/imx-common.h | 16 +++++++
 sound/soc/sof/imx/imx8.c       | 32 ++++++++++++++
 sound/soc/sof/imx/imx8m.c      | 33 +++++++++++++++
 4 files changed, 158 insertions(+)

diff --git a/sound/soc/sof/imx/imx-common.c b/sound/soc/sof/imx/imx-common.c
index 8826ef94f04a..20bcfab7b653 100644
--- a/sound/soc/sof/imx/imx-common.c
+++ b/sound/soc/sof/imx/imx-common.c
@@ -74,4 +74,81 @@ void imx8_dump(struct snd_sof_dev *sdev, u32 flags)
 }
 EXPORT_SYMBOL(imx8_dump);
 
+int imx8_parse_clocks(struct snd_sof_dev *sdev, struct imx_clocks *clks)
+{
+	int i;
+
+	clks->dsp_clks = devm_kcalloc(sdev->dev, clks->num_dsp_clks,
+				      sizeof(*clks->dsp_clks), GFP_KERNEL);
+	if (!clks->dsp_clks)
+		return -ENOMEM;
+
+	clks->dai_clks = devm_kcalloc(sdev->dev, clks->num_dai_clks,
+				      sizeof(*clks->dai_clks), GFP_KERNEL);
+	if (!clks->dai_clks)
+		return -ENOMEM;
+
+	for (i = 0; i < clks->num_dsp_clks; i++) {
+		clks->dsp_clks[i] = devm_clk_get(sdev->dev, clks->dsp_clks_names[i]);
+		if (IS_ERR(clks->dsp_clks[i])) {
+			dev_err(sdev->dev, "Failed to get clk %s\n", clks->dsp_clks_names[i]);
+			return PTR_ERR(clks->dsp_clks[i]);
+		}
+	}
+
+	for (i = 0; i < clks->num_dai_clks; i++)
+		clks->dai_clks[i] = devm_clk_get_optional(sdev->dev, clks->dai_clks_names[i]);
+
+	return 0;
+}
+EXPORT_SYMBOL(imx8_parse_clocks);
+
+int imx8_enable_clocks(struct snd_sof_dev *sdev, struct imx_clocks *clks)
+{
+	int i, j, ret;
+
+	for (i = 0; i < clks->num_dsp_clks; i++) {
+		ret = clk_prepare_enable(clks->dsp_clks[i]);
+		if (ret < 0) {
+			dev_err(sdev->dev, "Failed to enable clk %s\n",
+				clks->dsp_clks_names[i]);
+			goto err_dsp_clks;
+		}
+	}
+
+	for (j = 0; j < clks->num_dai_clks; j++) {
+		ret = clk_prepare_enable(clks->dai_clks[j]);
+		if (ret < 0) {
+			dev_err(sdev->dev, "Failed to enable clk %s\n",
+				clks->dai_clks_names[j]);
+			goto err_dai_clks;
+		}
+	}
+
+	return 0;
+
+err_dai_clks:
+	while (--j >= 0)
+		clk_disable_unprepare(clks->dai_clks[j]);
+
+err_dsp_clks:
+	while (--i >= 0)
+		clk_disable_unprepare(clks->dsp_clks[i]);
+
+	return ret;
+}
+EXPORT_SYMBOL(imx8_enable_clocks);
+
+void imx8_disable_clocks(struct snd_sof_dev *sdev, struct imx_clocks *clks)
+{
+	int i;
+
+	for (i = 0; i < clks->num_dsp_clks; i++)
+		clk_disable_unprepare(clks->dsp_clks[i]);
+
+	for (i = 0; i < clks->num_dai_clks; i++)
+		clk_disable_unprepare(clks->dai_clks[i]);
+}
+EXPORT_SYMBOL(imx8_disable_clocks);
+
 MODULE_LICENSE("Dual BSD/GPL");
diff --git a/sound/soc/sof/imx/imx-common.h b/sound/soc/sof/imx/imx-common.h
index 1cc7d6704182..a9bd16d61e8f 100644
--- a/sound/soc/sof/imx/imx-common.h
+++ b/sound/soc/sof/imx/imx-common.h
@@ -3,6 +3,8 @@
 #ifndef __IMX_COMMON_H__
 #define __IMX_COMMON_H__
 
+#include <linux/clk.h>
+
 #define EXCEPT_MAX_HDR_SIZE	0x400
 #define IMX8_STACK_DUMP_SIZE 32
 
@@ -13,4 +15,18 @@ void imx8_get_registers(struct snd_sof_dev *sdev,
 
 void imx8_dump(struct snd_sof_dev *sdev, u32 flags);
 
+struct imx_clocks {
+	const char **dsp_clks_names;
+	struct clk **dsp_clks;
+	int num_dsp_clks;
+
+	const char **dai_clks_names;
+	struct clk **dai_clks;
+	int num_dai_clks;
+};
+
+int imx8_parse_clocks(struct snd_sof_dev *sdev, struct imx_clocks *clks);
+int imx8_enable_clocks(struct snd_sof_dev *sdev, struct imx_clocks *clks);
+void imx8_disable_clocks(struct snd_sof_dev *sdev, struct imx_clocks *clks);
+
 #endif
diff --git a/sound/soc/sof/imx/imx8.c b/sound/soc/sof/imx/imx8.c
index fc1720c211a3..2937300200b2 100644
--- a/sound/soc/sof/imx/imx8.c
+++ b/sound/soc/sof/imx/imx8.c
@@ -41,6 +41,20 @@
 #define MBOX_OFFSET	0x800000
 #define MBOX_SIZE	0x1000
 
+#define IMX8_DSP_CLK_NUM	3
+static const char *imx8_dsp_clks_names[IMX8_DSP_CLK_NUM] = {
+	/* DSP clocks */
+	"ipg", "ocram", "core",
+};
+
+#define IMX8_DAI_CLK_NUM	9
+static const char *imx8_dai_clks_names[IMX8_DAI_CLK_NUM] = {
+	/* ESAI0 clocks */
+	"esai0_core", "esai0_extal", "esai0_fsys", "esai0_spba",
+	/* SAI1 clocks */
+	"sai1_bus", "sai1_mclk0", "sai1_mclk1", "sai1_mclk2", "sai1_mclk3",
+};
+
 struct imx8_priv {
 	struct device *dev;
 	struct snd_sof_dev *sdev;
@@ -57,6 +71,7 @@ struct imx8_priv {
 	struct device **pd_dev;
 	struct device_link **link;
 
+	struct imx_clocks *clks;
 };
 
 static void imx8_get_reply(struct snd_sof_dev *sdev)
@@ -223,6 +238,10 @@ static int imx8_probe(struct snd_sof_dev *sdev)
 	if (!priv)
 		return -ENOMEM;
 
+	priv->clks = devm_kzalloc(&pdev->dev, sizeof(*priv->clks), GFP_KERNEL);
+	if (!priv->clks)
+		return -ENOMEM;
+
 	sdev->num_cores = 1;
 	sdev->pdata->hw_pdata = priv;
 	priv->dev = sdev->dev;
@@ -336,6 +355,18 @@ static int imx8_probe(struct snd_sof_dev *sdev)
 	/* set default mailbox offset for FW ready message */
 	sdev->dsp_box.offset = MBOX_OFFSET;
 
+	/* init clocks info */
+	priv->clks->dsp_clks_names =  imx8_dsp_clks_names;
+	priv->clks->num_dsp_clks = IMX8_DSP_CLK_NUM;
+	priv->clks->dai_clks_names = imx8_dai_clks_names;
+	priv->clks->num_dai_clks = IMX8_DAI_CLK_NUM;
+
+	ret = imx8_parse_clocks(sdev, priv->clks);
+	if (ret < 0)
+		goto exit_pdev_unregister;
+
+	imx8_enable_clocks(sdev, priv->clks);
+
 	return 0;
 
 exit_pdev_unregister:
@@ -354,6 +385,7 @@ static int imx8_remove(struct snd_sof_dev *sdev)
 	struct imx8_priv *priv = sdev->pdata->hw_pdata;
 	int i;
 
+	imx8_disable_clocks(sdev, priv->clks);
 	platform_device_unregister(priv->ipc_dev);
 
 	for (i = 0; i < priv->num_domains; i++) {
diff --git a/sound/soc/sof/imx/imx8m.c b/sound/soc/sof/imx/imx8m.c
index 30624fafc632..482c25ab15ce 100644
--- a/sound/soc/sof/imx/imx8m.c
+++ b/sound/soc/sof/imx/imx8m.c
@@ -23,6 +23,20 @@
 #define MBOX_OFFSET	0x800000
 #define MBOX_SIZE	0x1000
 
+#define IMX8M_DSP_CLK_NUM	3
+static const char *imx8m_dsp_clks_names[IMX8M_DSP_CLK_NUM] = {
+	/* DSP clocks */
+	"ipg", "ocram", "core",
+};
+
+#define IMX8M_DAI_CLK_NUM	6
+static const char *imx8m_dai_clks_names[IMX8M_DAI_CLK_NUM] = {
+	/* SAI3 clocks */
+	"sai3_bus", "sai3_mclk0", "sai3_mclk1", "sai3_mclk2", "sai3_mclk3",
+	/* DMA3 clocks */
+	"sdma3_root",
+};
+
 struct imx8m_priv {
 	struct device *dev;
 	struct snd_sof_dev *sdev;
@@ -30,6 +44,8 @@ struct imx8m_priv {
 	/* DSP IPC handler */
 	struct imx_dsp_ipc *dsp_ipc;
 	struct platform_device *ipc_dev;
+
+	struct imx_clocks *clks;
 };
 
 static void imx8m_get_reply(struct snd_sof_dev *sdev)
@@ -143,6 +159,10 @@ static int imx8m_probe(struct snd_sof_dev *sdev)
 	if (!priv)
 		return -ENOMEM;
 
+	priv->clks = devm_kzalloc(&pdev->dev, sizeof(*priv->clks), GFP_KERNEL);
+	if (!priv->clks)
+		return -ENOMEM;
+
 	sdev->num_cores = 1;
 	sdev->pdata->hw_pdata = priv;
 	priv->dev = sdev->dev;
@@ -211,6 +231,18 @@ static int imx8m_probe(struct snd_sof_dev *sdev)
 	/* set default mailbox offset for FW ready message */
 	sdev->dsp_box.offset = MBOX_OFFSET;
 
+	/* init clocks info */
+	priv->clks->dsp_clks_names = imx8m_dsp_clks_names;
+	priv->clks->num_dsp_clks = IMX8M_DSP_CLK_NUM;
+	priv->clks->dai_clks_names = imx8m_dai_clks_names;
+	priv->clks->num_dai_clks = IMX8M_DAI_CLK_NUM;
+
+	ret = imx8_parse_clocks(sdev, priv->clks);
+	if (ret < 0)
+		goto exit_pdev_unregister;
+
+	imx8_enable_clocks(sdev, priv->clks);
+
 	return 0;
 
 exit_pdev_unregister:
@@ -222,6 +254,7 @@ static int imx8m_remove(struct snd_sof_dev *sdev)
 {
 	struct imx8m_priv *priv = sdev->pdata->hw_pdata;
 
+	imx8_disable_clocks(sdev, priv->clks);
 	platform_device_unregister(priv->ipc_dev);
 
 	return 0;
-- 
2.27.0

[PATCH 2/2] dt-bindings: dsp: fsl: Add DSP optional clocks documentation

[Daniel Baluta]

From: Daniel Baluta <daniel.baluta@nxp.com>

DSP node on the Linux kernel side must also take care of enabling
DAI/DMA related clocks.

By design we choose to manage DAI/DMA clocks from the kernel side because of
the architecture of some i.MX8 boards.

Clocks are handled by a special M4 core which runs a special firmware
called SCFW (System Controler firmware).

This communicates with A cores running Linux via a special Messaging
Unit and implements a custom API which is already implemented by the
Linux kernel i.MX clocks implementation.

Note that these clocks are optional. We can use the DSP without them.

Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
---
 .../devicetree/bindings/dsp/fsl,dsp.yaml      | 33 +++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml b/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml
index 7afc9f2be13a..1453668c0194 100644
--- a/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml
+++ b/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml
@@ -24,16 +24,49 @@ properties:
     maxItems: 1
 
   clocks:
+    minItems: 3
     items:
       - description: ipg clock
       - description: ocram clock
       - description: core clock
+      - description: esai0 core clock for accessing registers
+      - description: esai0 baud clock
+      - description: esai0 system clock
+      - description: esai0 spba clock required when ESAI is placed in slave mode
+      - description: SAI1 bus clock
+      - description: SAI1 master clock 0
+      - description: SAI1 master clock 1
+      - description: SAI1 master clock 2
+      - description: SAI1 master clock 3
+      - description: SAI3 bus clock
+      - description: SAI3 master clock 0
+      - description: SAI3 master clock 1
+      - description: SAI3 master clock 2
+      - description: SAI3 master clock 3
+      - description: SDMA3 root clock used for accessing registers
+
 
   clock-names:
+    minItems: 3
     items:
       - const: ipg
       - const: ocram
       - const: core
+      - const: esai0_core
+      - const: esai0_extal
+      - const: esai0_fsys
+      - const: esai0_spba
+      - const: sai1_bus
+      - const: sai1_mclk0
+      - const: sai1_mclk1
+      - const: sai1_mclk2
+      - const: sai1_mclk3
+      - const: sai3_bus
+      - const: sai3_mclk0
+      - const: sai3_mclk1
+      - const: sai3_mclk2
+      - const: sai3_mclk3
+      - const: smda3_root
 
   power-domains:
     description:
-- 
2.27.0

Re: [PATCH 1/2] ASoC: SOF: imx: Add code to manage DSP related clocks

[Péter Ujfalusi]

Hi Daniel,

On 02/09/2021 15:32, Daniel Baluta wrote:
> From: Daniel Baluta <daniel.baluta@nxp.com>
> 
> There are two types of clocks:
> 	* DSP IP clocks
> 	* DAI clocks
> 
> This clocks are necessary in order to power up DSP and DAIs.
> 
> We choose to enable DAI clocks here because of the way i.MX8/i.MX8X
> design handles resources (including clocks).
> 
> All clocks are managed by a separate core (named SCU) which communicates
> with Linux managed ARM core via a well known API.
> 
> We parse and enable the clocks in probe function and disable them in
> remove function.
> 
> Future patches will introduce Power Management support so that we
> disable clocks while DSP is not used or system enters power save.

Unfortunately this patch does not apply to next.

I might be a bit too cautius, but I would also add "&& COMMON_CLK" for 
the COMPILE_TEST in Kconfig or select it from where it is appropriate?

> Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
> ---
>   sound/soc/sof/imx/imx-common.c | 77 ++++++++++++++++++++++++++++++++++
>   sound/soc/sof/imx/imx-common.h | 16 +++++++
>   sound/soc/sof/imx/imx8.c       | 32 ++++++++++++++
>   sound/soc/sof/imx/imx8m.c      | 33 +++++++++++++++
>   4 files changed, 158 insertions(+)
> 
> diff --git a/sound/soc/sof/imx/imx8m.c b/sound/soc/sof/imx/imx8m.c
> index 30624fafc632..482c25ab15ce 100644
> --- a/sound/soc/sof/imx/imx8m.c
> +++ b/sound/soc/sof/imx/imx8m.c
> @@ -23,6 +23,20 @@
>   #define MBOX_OFFSET	0x800000
>   #define MBOX_SIZE	0x1000
>   
> +#define IMX8M_DSP_CLK_NUM	3
> +static const char *imx8m_dsp_clks_names[IMX8M_DSP_CLK_NUM] = {

static const char *imx8m_dsp_clks_names[]

+ ARRAY_SIZE(imx8m_dsp_clks_names) instead IMX8M_DSP_CLK_NUM ?


-- 
Péter

Re: [PATCH 1/2] ASoC: SOF: imx: Add code to manage DSP related clocks

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 253 bytes --]

On Thu, Sep 02, 2021 at 03:32:15PM +0300, Daniel Baluta wrote:

> +	for (i = 0; i < clks->num_dsp_clks; i++) {
> +		clks->dsp_clks[i] = devm_clk_get(sdev->dev, clks->dsp_clks_names[i]);

Looks like this could benefit from the use of the clk_bulk_ APIs?

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH 1/2] ASoC: SOF: imx: Add code to manage DSP related clocks

[Daniel Baluta]

On Fri, Sep 3, 2021 at 2:27 AM Mark Brown <broonie@kernel.org> wrote:
>
> On Thu, Sep 02, 2021 at 03:32:15PM +0300, Daniel Baluta wrote:
>
> > +     for (i = 0; i < clks->num_dsp_clks; i++) {
> > +             clks->dsp_clks[i] = devm_clk_get(sdev->dev, clks->dsp_clks_names[i]);
>
> Looks like this could benefit from the use of the clk_bulk_ APIs?

Indeed! I open coded exactly what clk_bulk API is doing! Will use it in v2.

Re: [PATCH 1/2] ASoC: SOF: imx: Add code to manage DSP related clocks

[Daniel Baluta]

On Thu, Sep 2, 2021 at 11:02 PM Péter Ujfalusi
<peter.ujfalusi@linux.intel.com> wrote:
>
> Hi Daniel,
>
> On 02/09/2021 15:32, Daniel Baluta wrote:
> > From: Daniel Baluta <daniel.baluta@nxp.com>
> >
> > There are two types of clocks:
> >       * DSP IP clocks
> >       * DAI clocks
> >
> > This clocks are necessary in order to power up DSP and DAIs.
> >
> > We choose to enable DAI clocks here because of the way i.MX8/i.MX8X
> > design handles resources (including clocks).
> >
> > All clocks are managed by a separate core (named SCU) which communicates
> > with Linux managed ARM core via a well known API.
> >
> > We parse and enable the clocks in probe function and disable them in
> > remove function.
> >
> > Future patches will introduce Power Management support so that we
> > disable clocks while DSP is not used or system enters power save.
>
> Unfortunately this patch does not apply to next.

Yes, because my patch is based on SOF topic/sof-dev branch and this small patch

https://github.com/thesofproject/linux/commit/b56c58b5938a626fb08fcf1d5e38d687b520ab89

is not in linux-next.

I plan to stay on SOF branch and get the review tags so we can merge
it in SOF tree.
>
> I might be a bit too cautius, but I would also add "&& COMMON_CLK" for
> the COMPILE_TEST in Kconfig or select it from where it is appropriate?

Maybe add a depends on COMMON_CLK for IMX hardware support? Altough,
if CLK support
is not selected clk API transforms itself into dummy wrappers.
>
> > Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
> > ---
> >   sound/soc/sof/imx/imx-common.c | 77 ++++++++++++++++++++++++++++++++++
> >   sound/soc/sof/imx/imx-common.h | 16 +++++++
> >   sound/soc/sof/imx/imx8.c       | 32 ++++++++++++++
> >   sound/soc/sof/imx/imx8m.c      | 33 +++++++++++++++
> >   4 files changed, 158 insertions(+)
> >
> > diff --git a/sound/soc/sof/imx/imx8m.c b/sound/soc/sof/imx/imx8m.c
> > index 30624fafc632..482c25ab15ce 100644
> > --- a/sound/soc/sof/imx/imx8m.c
> > +++ b/sound/soc/sof/imx/imx8m.c
> > @@ -23,6 +23,20 @@
> >   #define MBOX_OFFSET 0x800000
> >   #define MBOX_SIZE   0x1000
> >
> > +#define IMX8M_DSP_CLK_NUM    3
> > +static const char *imx8m_dsp_clks_names[IMX8M_DSP_CLK_NUM] = {
>
> static const char *imx8m_dsp_clks_names[]
>
> + ARRAY_SIZE(imx8m_dsp_clks_names) instead IMX8M_DSP_CLK_NUM ?

Yes, this is a good idea. Already fixed in v2 I sent eariler.