Discussion:
[PATCH v4 2/9] dt-bindings: clk: at91: add audio plls to the compatible list
Quentin Schulz
2017-07-25 07:37:03 UTC
Permalink
This new clock driver set allows to have a fractional divided clock that
would generate a precise clock particularly suitable for audio
applications.

The main audio pll clock has two children clocks: one that is connected
to the PMC, the other that can directly drive a pad. As these two routes
have different enable bits and different dividers and divider formulas,
they are handled by two different drivers.

This adds the audio plls (frac, pad and pmc) to the compatible list of
at91 clocks in DT binding.

Signed-off-by: Quentin Schulz <***@free-electrons.com>
Acked-by: Rob Herring <***@kernel.org>
Acked-by: Boris Brezillon <***@free-electrons.com>
---
Documentation/devicetree/bindings/clock/at91-clock.txt | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/at91-clock.txt b/Documentation/devicetree/bindings/clock/at91-clock.txt
index 5f3ad65..51c259a 100644
--- a/Documentation/devicetree/bindings/clock/at91-clock.txt
+++ b/Documentation/devicetree/bindings/clock/at91-clock.txt
@@ -81,6 +81,16 @@ Required properties:
"atmel,sama5d2-clk-generated":
at91 generated clock

+ "atmel,sama5d2-clk-audio-pll-frac":
+ at91 audio fractional pll
+
+ "atmel,sama5d2-clk-audio-pll-pad":
+ at91 audio pll CLK_AUDIO output pin
+
+ "atmel,sama5d2-clk-audio-pll-pmc"
+ at91 audio pll output on AUDIOPLLCLK that feeds the PMC
+ and can be used by peripheral clock or generic clock
+
Required properties for SCKC node:
- reg : defines the IO memory reserved for the SCKC.
- #size-cells : shall be 0 (reg is used to encode clk id).
--
git-series 0.9.1
Quentin Schulz
2017-07-25 07:37:02 UTC
Permalink
The driver requests the current clk rate of each of its parent clocks to
decide whether a clock rate is suitable or not. It does not request
determine_rate from a parent clock which could request a rate change in
parent clock (i.e. there is no parent rate propagation).

We know the rate we want (passed along req argument of the function) and
the parent clock rate, thus we know the closest rounded divisor, we
don't need to iterate over the available divisors to find the best one
for a given clock.

Signed-off-by: Quentin Schulz <***@free-electrons.com>
Acked-by: Boris Brezillon <***@free-electrons.com>
---
drivers/clk/at91/clk-generated.c | 25 ++++++++++++-------------
1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
index f0b7ae9..ef4b4e0 100644
--- a/drivers/clk/at91/clk-generated.c
+++ b/drivers/clk/at91/clk-generated.c
@@ -124,19 +124,18 @@ static int clk_generated_determine_rate(struct clk_hw *hw,
(gck->range.max && min_rate > gck->range.max))
continue;

- for (div = 1; div < GENERATED_MAX_DIV + 2; div++) {
- tmp_rate = DIV_ROUND_CLOSEST(parent_rate, div);
- tmp_diff = abs(req->rate - tmp_rate);
-
- if (best_diff < 0 || best_diff > tmp_diff) {
- best_rate = tmp_rate;
- best_diff = tmp_diff;
- req->best_parent_rate = parent_rate;
- req->best_parent_hw = parent;
- }
-
- if (!best_diff || tmp_rate < req->rate)
- break;
+ div = DIV_ROUND_CLOSEST(parent_rate, req->rate);
+ if (!div)
+ tmp_rate = parent_rate;
+ else
+ tmp_rate = parent_rate / div;
+ tmp_diff = abs(req->rate - tmp_rate);
+
+ if (best_diff < 0 || best_diff > tmp_diff) {
+ best_rate = tmp_rate;
+ best_diff = tmp_diff;
+ req->best_parent_rate = parent_rate;
+ req->best_parent_hw = parent;
}

if (!best_diff)
--
git-series 0.9.1
Nicolas Ferre
2017-07-25 15:28:02 UTC
Permalink
Post by Quentin Schulz
The driver requests the current clk rate of each of its parent clocks to
decide whether a clock rate is suitable or not. It does not request
determine_rate from a parent clock which could request a rate change in
parent clock (i.e. there is no parent rate propagation).
We know the rate we want (passed along req argument of the function) and
the parent clock rate, thus we know the closest rounded divisor, we
don't need to iterate over the available divisors to find the best one
for a given clock.
---
drivers/clk/at91/clk-generated.c | 25 ++++++++++++-------------
1 file changed, 12 insertions(+), 13 deletions(-)
diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
index f0b7ae9..ef4b4e0 100644
--- a/drivers/clk/at91/clk-generated.c
+++ b/drivers/clk/at91/clk-generated.c
@@ -124,19 +124,18 @@ static int clk_generated_determine_rate(struct clk_hw *hw,
(gck->range.max && min_rate > gck->range.max))
continue;
- for (div = 1; div < GENERATED_MAX_DIV + 2; div++) {
- tmp_rate = DIV_ROUND_CLOSEST(parent_rate, div);
- tmp_diff = abs(req->rate - tmp_rate);
-
- if (best_diff < 0 || best_diff > tmp_diff) {
- best_rate = tmp_rate;
- best_diff = tmp_diff;
- req->best_parent_rate = parent_rate;
- req->best_parent_hw = parent;
- }
-
- if (!best_diff || tmp_rate < req->rate)
- break;
+ div = DIV_ROUND_CLOSEST(parent_rate, req->rate);
+ if (!div)
+ tmp_rate = parent_rate;
+ else
+ tmp_rate = parent_rate / div;
+ tmp_diff = abs(req->rate - tmp_rate);
+
+ if (best_diff < 0 || best_diff > tmp_diff) {
+ best_rate = tmp_rate;
+ best_diff = tmp_diff;
+ req->best_parent_rate = parent_rate;
+ req->best_parent_hw = parent;
}
if (!best_diff)
--
Nicolas Ferre
Quentin Schulz
2017-07-25 07:37:06 UTC
Permalink
The way to find the best_diff and do the appropriate process afterwards
can be re-used.

This patch prepares the driver for an upcoming patch that will allow
clk_generated to determine the rate of the audio_pll.

Signed-off-by: Quentin Schulz <***@free-electrons.com>
Acked-by: Boris Brezillon <***@free-electrons.com>
---
drivers/clk/at91/clk-generated.c | 41 +++++++++++++++++++++------------
1 file changed, 27 insertions(+), 14 deletions(-)

diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
index ef4b4e0..7260e49 100644
--- a/drivers/clk/at91/clk-generated.c
+++ b/drivers/clk/at91/clk-generated.c
@@ -99,15 +99,36 @@ clk_generated_recalc_rate(struct clk_hw *hw,
return DIV_ROUND_CLOSEST(parent_rate, gck->gckdiv + 1);
}

+static void clk_generated_best_diff(struct clk_rate_request *req,
+ struct clk_hw *parent,
+ unsigned long parent_rate, u32 div,
+ int *best_diff, long *best_rate)
+{
+ unsigned long tmp_rate;
+ int tmp_diff;
+
+ if (!div)
+ tmp_rate = parent_rate;
+ else
+ tmp_rate = parent_rate / div;
+ tmp_diff = abs(req->rate - tmp_rate);
+
+ if (*best_diff < 0 || *best_diff > tmp_diff) {
+ *best_rate = tmp_rate;
+ *best_diff = tmp_diff;
+ req->best_parent_rate = parent_rate;
+ req->best_parent_hw = parent;
+ }
+}
+
static int clk_generated_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
struct clk_generated *gck = to_clk_generated(hw);
struct clk_hw *parent = NULL;
long best_rate = -EINVAL;
- unsigned long tmp_rate, min_rate;
+ unsigned long min_rate;
int best_diff = -1;
- int tmp_diff;
int i;

for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
@@ -125,18 +146,10 @@ static int clk_generated_determine_rate(struct clk_hw *hw,
continue;

div = DIV_ROUND_CLOSEST(parent_rate, req->rate);
- if (!div)
- tmp_rate = parent_rate;
- else
- tmp_rate = parent_rate / div;
- tmp_diff = abs(req->rate - tmp_rate);
-
- if (best_diff < 0 || best_diff > tmp_diff) {
- best_rate = tmp_rate;
- best_diff = tmp_diff;
- req->best_parent_rate = parent_rate;
- req->best_parent_hw = parent;
- }
+
+ clk_generated_best_diff(req, parent, parent_rate, div,
+ &best_diff, &best_rate);
+

if (!best_diff)
break;
--
git-series 0.9.1
Nicolas Ferre
2017-07-25 15:33:50 UTC
Permalink
Post by Quentin Schulz
The way to find the best_diff and do the appropriate process afterwards
can be re-used.
This patch prepares the driver for an upcoming patch that will allow
clk_generated to determine the rate of the audio_pll.
---
drivers/clk/at91/clk-generated.c | 41 +++++++++++++++++++++------------
1 file changed, 27 insertions(+), 14 deletions(-)
diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
index ef4b4e0..7260e49 100644
--- a/drivers/clk/at91/clk-generated.c
+++ b/drivers/clk/at91/clk-generated.c
@@ -99,15 +99,36 @@ clk_generated_recalc_rate(struct clk_hw *hw,
return DIV_ROUND_CLOSEST(parent_rate, gck->gckdiv + 1);
}
+static void clk_generated_best_diff(struct clk_rate_request *req,
+ struct clk_hw *parent,
+ unsigned long parent_rate, u32 div,
+ int *best_diff, long *best_rate)
+{
+ unsigned long tmp_rate;
+ int tmp_diff;
+
+ if (!div)
+ tmp_rate = parent_rate;
+ else
+ tmp_rate = parent_rate / div;
+ tmp_diff = abs(req->rate - tmp_rate);
+
+ if (*best_diff < 0 || *best_diff > tmp_diff) {
+ *best_rate = tmp_rate;
+ *best_diff = tmp_diff;
+ req->best_parent_rate = parent_rate;
+ req->best_parent_hw = parent;
+ }
+}
+
static int clk_generated_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
struct clk_generated *gck = to_clk_generated(hw);
struct clk_hw *parent = NULL;
long best_rate = -EINVAL;
- unsigned long tmp_rate, min_rate;
+ unsigned long min_rate;
int best_diff = -1;
- int tmp_diff;
int i;
for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
@@ -125,18 +146,10 @@ static int clk_generated_determine_rate(struct clk_hw *hw,
continue;
div = DIV_ROUND_CLOSEST(parent_rate, req->rate);
- if (!div)
- tmp_rate = parent_rate;
- else
- tmp_rate = parent_rate / div;
- tmp_diff = abs(req->rate - tmp_rate);
-
- if (best_diff < 0 || best_diff > tmp_diff) {
- best_rate = tmp_rate;
- best_diff = tmp_diff;
- req->best_parent_rate = parent_rate;
- req->best_parent_hw = parent;
- }
+
+ clk_generated_best_diff(req, parent, parent_rate, div,
+ &best_diff, &best_rate);
+
if (!best_diff)
break;
--
Nicolas Ferre
Quentin Schulz
2017-07-25 07:37:08 UTC
Permalink
Since gclk (generated-clk) is now able to determine the rate of the
audio_pll, there is no need for classd to have a direct phandle to the
audio_pll while already having a phandle to gclk.

This binding is used by no board in mainline so it is safe to be
modified.

Signed-off-by: Quentin Schulz <***@free-electrons.com>
Acked-by: Mark Brown <***@kernel.org>
Acked-by: Rob Herring <***@kernel.org>
---
Documentation/devicetree/bindings/sound/atmel-classd.txt | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/sound/atmel-classd.txt b/Documentation/devicetree/bindings/sound/atmel-classd.txt
index 549e701..8985510 100644
--- a/Documentation/devicetree/bindings/sound/atmel-classd.txt
+++ b/Documentation/devicetree/bindings/sound/atmel-classd.txt
@@ -13,13 +13,11 @@ Required properties:
Must be "tx".
- clock-names
Tuple listing input clock names.
- Required elements: "pclk", "gclk" and "aclk".
+ Required elements: "pclk" and "gclk".
- clocks
Please refer to clock-bindings.txt.
- assigned-clocks
Should be <&classd_gclk>.
-- assigned-clock-parents
- Should be <&audio_pll_pmc>.

Optional properties:
- pinctrl-names, pinctrl-0
@@ -45,10 +43,9 @@ classd: ***@fc048000 {
(AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1)
| AT91_XDMAC_DT_PERID(47))>;
dma-names = "tx";
- clocks = <&classd_clk>, <&classd_gclk>, <&audio_pll_pmc>;
- clock-names = "pclk", "gclk", "aclk";
+ clocks = <&classd_clk>, <&classd_gclk>;
+ clock-names = "pclk", "gclk";
assigned-clocks = <&classd_gclk>;
- assigned-clock-parents = <&audio_pll_pmc>;

pinctrl-names = "default";
pinctrl-0 = <&pinctrl_classd_default>;
--
git-series 0.9.1
Nicolas Ferre
2017-07-25 15:38:19 UTC
Permalink
Post by Quentin Schulz
Since gclk (generated-clk) is now able to determine the rate of the
audio_pll, there is no need for classd to have a direct phandle to the
audio_pll while already having a phandle to gclk.
This binding is used by no board in mainline so it is safe to be
modified.
---
Documentation/devicetree/bindings/sound/atmel-classd.txt | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/Documentation/devicetree/bindings/sound/atmel-classd.txt b/Documentation/devicetree/bindings/sound/atmel-classd.txt
index 549e701..8985510 100644
--- a/Documentation/devicetree/bindings/sound/atmel-classd.txt
+++ b/Documentation/devicetree/bindings/sound/atmel-classd.txt
Must be "tx".
- clock-names
Tuple listing input clock names.
- Required elements: "pclk", "gclk" and "aclk".
+ Required elements: "pclk" and "gclk".
- clocks
Please refer to clock-bindings.txt.
- assigned-clocks
Should be <&classd_gclk>.
-- assigned-clock-parents
- Should be <&audio_pll_pmc>.
- pinctrl-names, pinctrl-0
@@ -45,10 +43,9 @@ classd: ***@fc048000 {
(AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1)
| AT91_XDMAC_DT_PERID(47))>;
dma-names = "tx";
- clocks = <&classd_clk>, <&classd_gclk>, <&audio_pll_pmc>;
- clock-names = "pclk", "gclk", "aclk";
+ clocks = <&classd_clk>, <&classd_gclk>;
+ clock-names = "pclk", "gclk";
assigned-clocks = <&classd_gclk>;
- assigned-clock-parents = <&audio_pll_pmc>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_classd_default>;
--
Nicolas Ferre
Quentin Schulz
2017-07-25 07:37:05 UTC
Permalink
From: Cyrille Pitchen <***@atmel.com>

This patch adds nodes for the classd device and its generated clock.

Signed-off-by: Cyrille Pitchen <***@atmel.com>
Signed-off-by: Nicolas Ferre <***@atmel.com>
Signed-off-by: Quentin Schulz <***@free-electrons.com>
---
arch/arm/boot/dts/sama5d2.dtsi | 39 ++++++++++++++++++++++++++++++++++-
1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/sama5d2.dtsi b/arch/arm/boot/dts/sama5d2.dtsi
index 534ee6f..38d2216 100644
--- a/arch/arm/boot/dts/sama5d2.dtsi
+++ b/arch/arm/boot/dts/sama5d2.dtsi
@@ -505,6 +505,24 @@
clocks = <&plla>;
};

+ audio_pll_frac: audiopll_fracck {
+ compatible = "atmel,sama5d2-clk-audio-pll-frac";
+ #clock-cells = <0>;
+ clocks = <&main>;
+ };
+
+ audio_pll_pad: audiopll_padck {
+ compatible = "atmel,sama5d2-clk-audio-pll-pad";
+ #clock-cells = <0>;
+ clocks = <&audio_pll_frac>;
+ };
+
+ audio_pll_pmc: audiopll_pmcck {
+ compatible = "atmel,sama5d2-clk-audio-pll-pmc";
+ #clock-cells = <0>;
+ clocks = <&audio_pll_frac>;
+ };
+
utmi: utmick {
compatible = "atmel,at91sam9x5-clk-utmi";
#clock-cells = <0>;
@@ -906,7 +924,7 @@
#address-cells = <1>;
#size-cells = <0>;
interrupt-parent = <&pmc>;
- clocks = <&clk32k>, <&main>, <&plladiv>, <&utmi>, <&mck>;
+ clocks = <&clk32k>, <&main>, <&plladiv>, <&utmi>, <&mck>, <&audio_pll_pmc>;

sdmmc0_gclk: sdmmc0_gclk {
#clock-cells = <0>;
@@ -967,6 +985,12 @@
reg = <57>;
atmel,clk-output-range = <0 80000000>;
};
+
+ classd_gclk: classd_gclk {
+ #clock-cells = <0>;
+ reg = <59>;
+ atmel,clk-output-range = <0 100000000>;
+ };
};
};

@@ -1444,6 +1468,19 @@
status = "okay";
};

+ classd: ***@fc048000 {
+ compatible = "atmel,sama5d2-classd";
+ reg = <0xfc048000 0x100>;
+ interrupts = <59 IRQ_TYPE_LEVEL_HIGH 7>;
+ dmas = <&dma0
+ (AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1) |
+ AT91_XDMAC_DT_PERID(47))>;
+ dma-names = "tx";
+ clocks = <&classd_clk>, <&classd_gclk>;
+ clock-names = "pclk", "gclk";
+ status = "disabled";
+ };
+
can1: ***@fc050000 {
compatible = "bosch,m_can";
reg = <0xfc050000 0x4000>, <0x210000 0x4000>;
--
git-series 0.9.1
Quentin Schulz
2017-07-25 07:37:09 UTC
Permalink
Since gclk (generated-clk) is now able to determine the rate of the
audio_pll, there is no need for classd to have a direct phandle to the
audio_pll while already having a phandle to gclk.

Thus, remove all mentions to aclk in classd driver and update macros and
variable names.

Signed-off-by: Quentin Schulz <***@free-electrons.com>
Acked-by: Mark Brown <***@kernel.org>
---
sound/soc/atmel/atmel-classd.c | 47 ++++++++++-------------------------
1 file changed, 14 insertions(+), 33 deletions(-)

diff --git a/sound/soc/atmel/atmel-classd.c b/sound/soc/atmel/atmel-classd.c
index b7ef8c5..be6b775 100644
--- a/sound/soc/atmel/atmel-classd.c
+++ b/sound/soc/atmel/atmel-classd.c
@@ -32,7 +32,6 @@ struct atmel_classd {
struct regmap *regmap;
struct clk *pclk;
struct clk *gclk;
- struct clk *aclk;
int irq;
const struct atmel_classd_pdata *pdata;
};
@@ -330,11 +329,6 @@ static int atmel_classd_codec_dai_startup(struct snd_pcm_substream *substream,
{
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct atmel_classd *dd = snd_soc_card_get_drvdata(rtd->card);
- int ret;
-
- ret = clk_prepare_enable(dd->aclk);
- if (ret)
- return ret;

return clk_prepare_enable(dd->gclk);
}
@@ -357,31 +351,31 @@ static int atmel_classd_codec_dai_digital_mute(struct snd_soc_dai *codec_dai,
return 0;
}

-#define CLASSD_ACLK_RATE_11M2896_MPY_8 (112896 * 100 * 8)
-#define CLASSD_ACLK_RATE_12M288_MPY_8 (12288 * 1000 * 8)
+#define CLASSD_GCLK_RATE_11M2896_MPY_8 (112896 * 100 * 8)
+#define CLASSD_GCLK_RATE_12M288_MPY_8 (12288 * 1000 * 8)

static struct {
int rate;
int sample_rate;
int dsp_clk;
- unsigned long aclk_rate;
+ unsigned long gclk_rate;
} const sample_rates[] = {
{ 8000, CLASSD_INTPMR_FRAME_8K,
- CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_ACLK_RATE_12M288_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_GCLK_RATE_12M288_MPY_8 },
{ 16000, CLASSD_INTPMR_FRAME_16K,
- CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_ACLK_RATE_12M288_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_GCLK_RATE_12M288_MPY_8 },
{ 32000, CLASSD_INTPMR_FRAME_32K,
- CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_ACLK_RATE_12M288_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_GCLK_RATE_12M288_MPY_8 },
{ 48000, CLASSD_INTPMR_FRAME_48K,
- CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_ACLK_RATE_12M288_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_GCLK_RATE_12M288_MPY_8 },
{ 96000, CLASSD_INTPMR_FRAME_96K,
- CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_ACLK_RATE_12M288_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_GCLK_RATE_12M288_MPY_8 },
{ 22050, CLASSD_INTPMR_FRAME_22K,
- CLASSD_INTPMR_DSP_CLK_FREQ_11M2896, CLASSD_ACLK_RATE_11M2896_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_11M2896, CLASSD_GCLK_RATE_11M2896_MPY_8 },
{ 44100, CLASSD_INTPMR_FRAME_44K,
- CLASSD_INTPMR_DSP_CLK_FREQ_11M2896, CLASSD_ACLK_RATE_11M2896_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_11M2896, CLASSD_GCLK_RATE_11M2896_MPY_8 },
{ 88200, CLASSD_INTPMR_FRAME_88K,
- CLASSD_INTPMR_DSP_CLK_FREQ_11M2896, CLASSD_ACLK_RATE_11M2896_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_11M2896, CLASSD_GCLK_RATE_11M2896_MPY_8 },
};

static int
@@ -410,13 +404,12 @@ atmel_classd_codec_dai_hw_params(struct snd_pcm_substream *substream,
}

dev_dbg(codec->dev,
- "Selected SAMPLE_RATE of %dHz, ACLK_RATE of %ldHz\n",
- sample_rates[best].rate, sample_rates[best].aclk_rate);
+ "Selected SAMPLE_RATE of %dHz, GCLK_RATE of %ldHz\n",
+ sample_rates[best].rate, sample_rates[best].gclk_rate);

clk_disable_unprepare(dd->gclk);
- clk_disable_unprepare(dd->aclk);

- ret = clk_set_rate(dd->aclk, sample_rates[best].aclk_rate);
+ ret = clk_set_rate(dd->gclk, sample_rates[best].gclk_rate);
if (ret)
return ret;

@@ -426,10 +419,6 @@ atmel_classd_codec_dai_hw_params(struct snd_pcm_substream *substream,

snd_soc_update_bits(codec, CLASSD_INTPMR, mask, val);

- ret = clk_prepare_enable(dd->aclk);
- if (ret)
- return ret;
-
return clk_prepare_enable(dd->gclk);
}

@@ -441,7 +430,6 @@ atmel_classd_codec_dai_shutdown(struct snd_pcm_substream *substream,
struct atmel_classd *dd = snd_soc_card_get_drvdata(rtd->card);

clk_disable_unprepare(dd->gclk);
- clk_disable_unprepare(dd->aclk);
}

static int atmel_classd_codec_dai_prepare(struct snd_pcm_substream *substream,
@@ -596,13 +584,6 @@ static int atmel_classd_probe(struct platform_device *pdev)
return ret;
}

- dd->aclk = devm_clk_get(dev, "aclk");
- if (IS_ERR(dd->aclk)) {
- ret = PTR_ERR(dd->aclk);
- dev_err(dev, "failed to get audio clock: %d\n", ret);
- return ret;
- }
-
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
io_base = devm_ioremap_resource(dev, res);
if (IS_ERR(io_base)) {
--
git-series 0.9.1
Nicolas Ferre
2017-07-25 15:40:14 UTC
Permalink
Post by Quentin Schulz
Since gclk (generated-clk) is now able to determine the rate of the
audio_pll, there is no need for classd to have a direct phandle to the
audio_pll while already having a phandle to gclk.
Thus, remove all mentions to aclk in classd driver and update macros and
variable names.
---
sound/soc/atmel/atmel-classd.c | 47 ++++++++++-------------------------
1 file changed, 14 insertions(+), 33 deletions(-)
diff --git a/sound/soc/atmel/atmel-classd.c b/sound/soc/atmel/atmel-classd.c
index b7ef8c5..be6b775 100644
--- a/sound/soc/atmel/atmel-classd.c
+++ b/sound/soc/atmel/atmel-classd.c
@@ -32,7 +32,6 @@ struct atmel_classd {
struct regmap *regmap;
struct clk *pclk;
struct clk *gclk;
- struct clk *aclk;
int irq;
const struct atmel_classd_pdata *pdata;
};
@@ -330,11 +329,6 @@ static int atmel_classd_codec_dai_startup(struct snd_pcm_substream *substream,
{
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct atmel_classd *dd = snd_soc_card_get_drvdata(rtd->card);
- int ret;
-
- ret = clk_prepare_enable(dd->aclk);
- if (ret)
- return ret;
return clk_prepare_enable(dd->gclk);
}
@@ -357,31 +351,31 @@ static int atmel_classd_codec_dai_digital_mute(struct snd_soc_dai *codec_dai,
return 0;
}
-#define CLASSD_ACLK_RATE_11M2896_MPY_8 (112896 * 100 * 8)
-#define CLASSD_ACLK_RATE_12M288_MPY_8 (12288 * 1000 * 8)
+#define CLASSD_GCLK_RATE_11M2896_MPY_8 (112896 * 100 * 8)
+#define CLASSD_GCLK_RATE_12M288_MPY_8 (12288 * 1000 * 8)
static struct {
int rate;
int sample_rate;
int dsp_clk;
- unsigned long aclk_rate;
+ unsigned long gclk_rate;
} const sample_rates[] = {
{ 8000, CLASSD_INTPMR_FRAME_8K,
- CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_ACLK_RATE_12M288_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_GCLK_RATE_12M288_MPY_8 },
{ 16000, CLASSD_INTPMR_FRAME_16K,
- CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_ACLK_RATE_12M288_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_GCLK_RATE_12M288_MPY_8 },
{ 32000, CLASSD_INTPMR_FRAME_32K,
- CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_ACLK_RATE_12M288_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_GCLK_RATE_12M288_MPY_8 },
{ 48000, CLASSD_INTPMR_FRAME_48K,
- CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_ACLK_RATE_12M288_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_GCLK_RATE_12M288_MPY_8 },
{ 96000, CLASSD_INTPMR_FRAME_96K,
- CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_ACLK_RATE_12M288_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_GCLK_RATE_12M288_MPY_8 },
{ 22050, CLASSD_INTPMR_FRAME_22K,
- CLASSD_INTPMR_DSP_CLK_FREQ_11M2896, CLASSD_ACLK_RATE_11M2896_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_11M2896, CLASSD_GCLK_RATE_11M2896_MPY_8 },
{ 44100, CLASSD_INTPMR_FRAME_44K,
- CLASSD_INTPMR_DSP_CLK_FREQ_11M2896, CLASSD_ACLK_RATE_11M2896_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_11M2896, CLASSD_GCLK_RATE_11M2896_MPY_8 },
{ 88200, CLASSD_INTPMR_FRAME_88K,
- CLASSD_INTPMR_DSP_CLK_FREQ_11M2896, CLASSD_ACLK_RATE_11M2896_MPY_8 },
+ CLASSD_INTPMR_DSP_CLK_FREQ_11M2896, CLASSD_GCLK_RATE_11M2896_MPY_8 },
};
static int
@@ -410,13 +404,12 @@ atmel_classd_codec_dai_hw_params(struct snd_pcm_substream *substream,
}
dev_dbg(codec->dev,
- "Selected SAMPLE_RATE of %dHz, ACLK_RATE of %ldHz\n",
- sample_rates[best].rate, sample_rates[best].aclk_rate);
+ "Selected SAMPLE_RATE of %dHz, GCLK_RATE of %ldHz\n",
+ sample_rates[best].rate, sample_rates[best].gclk_rate);
clk_disable_unprepare(dd->gclk);
- clk_disable_unprepare(dd->aclk);
- ret = clk_set_rate(dd->aclk, sample_rates[best].aclk_rate);
+ ret = clk_set_rate(dd->gclk, sample_rates[best].gclk_rate);
if (ret)
return ret;
@@ -426,10 +419,6 @@ atmel_classd_codec_dai_hw_params(struct snd_pcm_substream *substream,
snd_soc_update_bits(codec, CLASSD_INTPMR, mask, val);
- ret = clk_prepare_enable(dd->aclk);
- if (ret)
- return ret;
-
return clk_prepare_enable(dd->gclk);
}
@@ -441,7 +430,6 @@ atmel_classd_codec_dai_shutdown(struct snd_pcm_substream *substream,
struct atmel_classd *dd = snd_soc_card_get_drvdata(rtd->card);
clk_disable_unprepare(dd->gclk);
- clk_disable_unprepare(dd->aclk);
}
static int atmel_classd_codec_dai_prepare(struct snd_pcm_substream *substream,
@@ -596,13 +584,6 @@ static int atmel_classd_probe(struct platform_device *pdev)
return ret;
}
- dd->aclk = devm_clk_get(dev, "aclk");
- if (IS_ERR(dd->aclk)) {
- ret = PTR_ERR(dd->aclk);
- dev_err(dev, "failed to get audio clock: %d\n", ret);
- return ret;
- }
-
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
io_base = devm_ioremap_resource(dev, res);
if (IS_ERR(io_base)) {
--
Nicolas Ferre
Quentin Schulz
2017-07-25 07:37:10 UTC
Permalink
From: Cyrille Pitchen <***@atmel.com>

This patch adds the pin muxing for classd and enables it.

Signed-off-by: Cyrille Pitchen <***@atmel.com>
Signed-off-by: Nicolas Ferre <***@atmel.com>
Signed-off-by: Quentin Schulz <***@free-electrons.com>
---
arch/arm/boot/dts/at91-sama5d2_xplained.dts | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/arch/arm/boot/dts/at91-sama5d2_xplained.dts b/arch/arm/boot/dts/at91-sama5d2_xplained.dts
index 6eec8dc..c7e9ccf 100644
--- a/arch/arm/boot/dts/at91-sama5d2_xplained.dts
+++ b/arch/arm/boot/dts/at91-sama5d2_xplained.dts
@@ -355,6 +355,14 @@
bias-pull-up;
};

+ pinctrl_classd_default: classd_default {
+ pinmux = <PIN_PB1__CLASSD_R0>,
+ <PIN_PB2__CLASSD_R1>,
+ <PIN_PB3__CLASSD_R2>,
+ <PIN_PB4__CLASSD_R3>;
+ bias-pull-up;
+ };
+
pinctrl_flx0_default: flx0_default {
pinmux = <PIN_PB28__FLEXCOM0_IO0>,
<PIN_PB29__FLEXCOM0_IO1>;
@@ -488,6 +496,14 @@

};

+ classd: ***@fc048000 {
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_classd_default>;
+ atmel,pwm-type = "diff";
+ atmel,non-overlap-time = <10>;
+ status = "okay";
+ };
+
can1: ***@fc050000 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_can1_default>;
--
git-series 0.9.1
Quentin Schulz
2017-07-25 07:37:04 UTC
Permalink
This new clock driver set allows to have a fractional divided clock that
would generate a precise clock particularly suitable for audio
applications.

The main audio pll clock has two children clocks: one that is connected
to the PMC, the other that can directly drive a pad. As these two routes
have different enable bits and different dividers and divider formulas,
they are handled by two different drivers. Each of them could modify the
rate of the main audio pll parent.

The main audio pll clock can output 620MHz to 700MHz.

Signed-off-by: Nicolas Ferre <***@atmel.com>
Signed-off-by: Quentin Schulz <***@free-electrons.com>
Acked-by: Boris Brezillon <***@free-electrons.com>
---
arch/arm/mach-at91/Kconfig | 4 +-
drivers/clk/at91/Makefile | 1 +-
drivers/clk/at91/clk-audio-pll.c | 531 ++++++++++++++++++++++++++++++++-
include/linux/clk/at91_pmc.h | 25 ++-
4 files changed, 561 insertions(+)
create mode 100644 drivers/clk/at91/clk-audio-pll.c

diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index d735e5f..9ae14d5 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -26,6 +26,7 @@ config SOC_SAMA5D2
select HAVE_AT91_USB_CLK
select HAVE_AT91_H32MX
select HAVE_AT91_GENERATED_CLK
+ select HAVE_AT91_AUDIO_PLL
select PINCTRL_AT91PIO4
help
Select this if ou are using one of Atmel's SAMA5D2 family SoC.
@@ -125,6 +126,9 @@ config HAVE_AT91_H32MX
config HAVE_AT91_GENERATED_CLK
bool

+config HAVE_AT91_AUDIO_PLL
+ bool
+
config SOC_SAM_V4_V5
bool

diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile
index 13e67bd..c68947b 100644
--- a/drivers/clk/at91/Makefile
+++ b/drivers/clk/at91/Makefile
@@ -6,6 +6,7 @@ obj-y += pmc.o sckc.o
obj-y += clk-slow.o clk-main.o clk-pll.o clk-plldiv.o clk-master.o
obj-y += clk-system.o clk-peripheral.o clk-programmable.o

+obj-$(CONFIG_HAVE_AT91_AUDIO_PLL) += clk-audio-pll.o
obj-$(CONFIG_HAVE_AT91_UTMI) += clk-utmi.o
obj-$(CONFIG_HAVE_AT91_USB_CLK) += clk-usb.o
obj-$(CONFIG_HAVE_AT91_SMD) += clk-smd.o
diff --git a/drivers/clk/at91/clk-audio-pll.c b/drivers/clk/at91/clk-audio-pll.c
new file mode 100644
index 0000000..fc113f0
--- /dev/null
+++ b/drivers/clk/at91/clk-audio-pll.c
@@ -0,0 +1,531 @@
+/*
+ * Copyright (C) 2016 Atmel Corporation,
+ * Songjun Wu <***@atmel.com>,
+ * Nicolas Ferre <***@atmel.com>
+ * Copyright (C) 2017 Free Electrons,
+ * Quentin Schulz <***@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * The Sama5d2 SoC has two audio PLLs (PMC and PAD) that shares the same parent
+ * (FRAC). FRAC can output between 620 and 700MHz and only multiply the rate of
+ * its own parent. PMC and PAD can then divide the FRAC rate to best match the
+ * asked rate.
+ *
+ * Traits of FRAC clock:
+ * enable - clk_enable writes nd, fracr parameters and enables PLL
+ * rate - rate is adjustable.
+ * clk->rate = parent->rate * ((nd + 1) + (fracr / 2^22))
+ * parent - fixed parent. No clk_set_parent support
+ *
+ * Traits of PMC clock:
+ * enable - clk_enable writes qdpmc, and enables PMC output
+ * rate - rate is adjustable.
+ * clk->rate = parent->rate / (qdpmc + 1)
+ * parent - fixed parent. No clk_set_parent support
+ *
+ * Traits of PAD clock:
+ * enable - clk_enable writes divisors and enables PAD output
+ * rate - rate is adjustable.
+ * clk->rate = parent->rate / (qdaudio * div))
+ * parent - fixed parent. No clk_set_parent support
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/clk/at91_pmc.h>
+#include <linux/of.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define AUDIO_PLL_DIV_FRAC BIT(22)
+#define AUDIO_PLL_ND_MAX (AT91_PMC_AUDIO_PLL_ND_MASK >> \
+ AT91_PMC_AUDIO_PLL_ND_OFFSET)
+
+#define AUDIO_PLL_QDPAD(qd, div) ((AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV(qd) & \
+ AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV_MASK) | \
+ (AT91_PMC_AUDIO_PLL_QDPAD_DIV(div) & \
+ AT91_PMC_AUDIO_PLL_QDPAD_DIV_MASK))
+
+#define AUDIO_PLL_QDPMC_MAX (AT91_PMC_AUDIO_PLL_QDPMC_MASK >> \
+ AT91_PMC_AUDIO_PLL_QDPMC_OFFSET)
+
+#define AUDIO_PLL_FOUT_MIN 620000000UL
+#define AUDIO_PLL_FOUT_MAX 700000000UL
+
+struct clk_audio_frac {
+ struct clk_hw hw;
+ struct regmap *regmap;
+ u32 fracr;
+ u8 nd;
+};
+
+struct clk_audio_pad {
+ struct clk_hw hw;
+ struct regmap *regmap;
+ u8 qdaudio;
+ u8 div;
+};
+
+struct clk_audio_pmc {
+ struct clk_hw hw;
+ struct regmap *regmap;
+ u8 qdpmc;
+};
+
+#define to_clk_audio_frac(hw) container_of(hw, struct clk_audio_frac, hw)
+#define to_clk_audio_pad(hw) container_of(hw, struct clk_audio_pad, hw)
+#define to_clk_audio_pmc(hw) container_of(hw, struct clk_audio_pmc, hw)
+
+static int clk_audio_pll_frac_enable(struct clk_hw *hw)
+{
+ struct clk_audio_frac *frac = to_clk_audio_frac(hw);
+
+ regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL0,
+ AT91_PMC_AUDIO_PLL_RESETN, 0);
+ regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL0,
+ AT91_PMC_AUDIO_PLL_RESETN,
+ AT91_PMC_AUDIO_PLL_RESETN);
+ regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL1,
+ AT91_PMC_AUDIO_PLL_FRACR_MASK, frac->fracr);
+
+ /*
+ * reset and enable have to be done in 2 separated writes
+ * for AT91_PMC_AUDIO_PLL0
+ */
+ regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL0,
+ AT91_PMC_AUDIO_PLL_PLLEN |
+ AT91_PMC_AUDIO_PLL_ND_MASK,
+ AT91_PMC_AUDIO_PLL_PLLEN |
+ AT91_PMC_AUDIO_PLL_ND(frac->nd));
+
+ return 0;
+}
+
+static int clk_audio_pll_pad_enable(struct clk_hw *hw)
+{
+ struct clk_audio_pad *apad_ck = to_clk_audio_pad(hw);
+
+ regmap_update_bits(apad_ck->regmap, AT91_PMC_AUDIO_PLL1,
+ AT91_PMC_AUDIO_PLL_QDPAD_MASK,
+ AUDIO_PLL_QDPAD(apad_ck->qdaudio, apad_ck->div));
+ regmap_update_bits(apad_ck->regmap, AT91_PMC_AUDIO_PLL0,
+ AT91_PMC_AUDIO_PLL_PADEN, AT91_PMC_AUDIO_PLL_PADEN);
+
+ return 0;
+}
+
+static int clk_audio_pll_pmc_enable(struct clk_hw *hw)
+{
+ struct clk_audio_pmc *apmc_ck = to_clk_audio_pmc(hw);
+
+ regmap_update_bits(apmc_ck->regmap, AT91_PMC_AUDIO_PLL0,
+ AT91_PMC_AUDIO_PLL_PMCEN |
+ AT91_PMC_AUDIO_PLL_QDPMC_MASK,
+ AT91_PMC_AUDIO_PLL_PMCEN |
+ AT91_PMC_AUDIO_PLL_QDPMC(apmc_ck->qdpmc));
+ return 0;
+}
+
+static void clk_audio_pll_frac_disable(struct clk_hw *hw)
+{
+ struct clk_audio_frac *frac = to_clk_audio_frac(hw);
+
+ regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL0,
+ AT91_PMC_AUDIO_PLL_PLLEN, 0);
+ /* do it in 2 separated writes */
+ regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL0,
+ AT91_PMC_AUDIO_PLL_RESETN, 0);
+}
+
+static void clk_audio_pll_pad_disable(struct clk_hw *hw)
+{
+ struct clk_audio_pad *apad_ck = to_clk_audio_pad(hw);
+
+ regmap_update_bits(apad_ck->regmap, AT91_PMC_AUDIO_PLL0,
+ AT91_PMC_AUDIO_PLL_PADEN, 0);
+}
+
+static void clk_audio_pll_pmc_disable(struct clk_hw *hw)
+{
+ struct clk_audio_pmc *apmc_ck = to_clk_audio_pmc(hw);
+
+ regmap_update_bits(apmc_ck->regmap, AT91_PMC_AUDIO_PLL0,
+ AT91_PMC_AUDIO_PLL_PMCEN, 0);
+}
+
+static unsigned long clk_audio_pll_fout(unsigned long parent_rate,
+ unsigned long nd, unsigned long fracr)
+{
+ unsigned long long fr = (unsigned long long)parent_rate * fracr;
+
+ pr_debug("A PLL: %s, fr = %llu\n", __func__, fr);
+
+ fr = DIV_ROUND_CLOSEST_ULL(fr, AUDIO_PLL_DIV_FRAC);
+
+ pr_debug("A PLL: %s, fr = %llu\n", __func__, fr);
+
+ return parent_rate * (nd + 1) + fr;
+}
+
+static unsigned long clk_audio_pll_frac_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_audio_frac *frac = to_clk_audio_frac(hw);
+ unsigned long fout;
+
+ fout = clk_audio_pll_fout(parent_rate, frac->nd, frac->fracr);
+
+ pr_debug("A PLL: %s, fout = %lu (nd = %u, fracr = %lu)\n", __func__,
+ fout, frac->nd, (unsigned long)frac->fracr);
+
+ return fout;
+}
+
+static unsigned long clk_audio_pll_pad_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_audio_pad *apad_ck = to_clk_audio_pad(hw);
+ unsigned long apad_rate = 0;
+
+ if (apad_ck->qdaudio && apad_ck->div)
+ apad_rate = parent_rate / (apad_ck->qdaudio * apad_ck->div);
+
+ pr_debug("A PLL/PAD: %s, apad_rate = %lu (div = %u, qdaudio = %u)\n",
+ __func__, apad_rate, apad_ck->div, apad_ck->qdaudio);
+
+ return apad_rate;
+}
+
+static unsigned long clk_audio_pll_pmc_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_audio_pmc *apmc_ck = to_clk_audio_pmc(hw);
+ unsigned long apmc_rate = 0;
+
+ apmc_rate = parent_rate / (apmc_ck->qdpmc + 1);
+
+ pr_debug("A PLL/PMC: %s, apmc_rate = %lu (qdpmc = %u)\n", __func__,
+ apmc_rate, apmc_ck->qdpmc);
+
+ return apmc_rate;
+}
+
+static int clk_audio_pll_frac_compute_frac(unsigned long rate,
+ unsigned long parent_rate,
+ unsigned long *nd,
+ unsigned long *fracr)
+{
+ unsigned long long tmp, rem;
+
+ if (!rate)
+ return -EINVAL;
+
+ tmp = rate;
+ rem = do_div(tmp, parent_rate);
+ if (!tmp || tmp >= AUDIO_PLL_ND_MAX)
+ return -EINVAL;
+
+ *nd = tmp - 1;
+
+ tmp = rem * AUDIO_PLL_DIV_FRAC;
+ tmp = DIV_ROUND_CLOSEST_ULL(tmp, parent_rate);
+ if (tmp > AT91_PMC_AUDIO_PLL_FRACR_MASK)
+ return -EINVAL;
+
+ /* we can cast here as we verified the bounds just above */
+ *fracr = (unsigned long)tmp;
+
+ return 0;
+}
+
+static long clk_audio_pll_frac_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ long best_rate = -EINVAL;
+ unsigned long fracr, nd;
+ int ret;
+
+ pr_debug("A PLL: %s, rate = %lu (parent_rate = %lu)\n", __func__, rate,
+ *parent_rate);
+
+ rate = clamp(rate, AUDIO_PLL_FOUT_MIN, AUDIO_PLL_FOUT_MAX);
+
+ ret = clk_audio_pll_frac_compute_frac(rate, *parent_rate, &nd, &fracr);
+ if (ret)
+ return ret;
+
+ best_rate = clk_audio_pll_fout(*parent_rate, nd, fracr);
+
+ pr_debug("A PLL: %s, best_rate = %lu (nd = %lu, fracr = %lu)\n",
+ __func__, best_rate, nd, fracr);
+
+ return best_rate;
+}
+
+static long clk_audio_pll_pad_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct clk_hw *pclk = clk_hw_get_parent(hw);
+ long best_rate = -EINVAL;
+ unsigned long best_parent_rate;
+ unsigned long tmp_qd;
+ u32 div;
+ long tmp_rate;
+ int tmp_diff;
+ int best_diff = -1;
+
+ pr_debug("A PLL/PAD: %s, rate = %lu (parent_rate = %lu)\n", __func__,
+ rate, *parent_rate);
+
+ /*
+ * Rate divisor is actually made of two different divisors, multiplied
+ * between themselves before dividing the rate.
+ * tmp_qd goes from 1 to 31 and div is either 2 or 3.
+ * In order to avoid testing twice the rate divisor (e.g. divisor 12 can
+ * be found with (tmp_qd, div) = (2, 6) or (3, 4)), we remove any loop
+ * for a rate divisor when div is 2 and tmp_qd is a multiple of 3.
+ * We cannot inverse it (condition div is 3 and tmp_qd is even) or we
+ * would miss some rate divisor that aren't reachable with div being 2
+ * (e.g. rate divisor 90 is made with div = 3 and tmp_qd = 30, thus
+ * tmp_qd is even so we skip it because we think div 2 could make this
+ * rate divisor which isn't possible since tmp_qd has to be <= 31).
+ */
+ for (tmp_qd = 1; tmp_qd < AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV_MAX; tmp_qd++)
+ for (div = 2; div <= 3; div++) {
+ if (div == 2 && tmp_qd % 3 == 0)
+ continue;
+
+ best_parent_rate = clk_hw_round_rate(pclk,
+ rate * tmp_qd * div);
+ tmp_rate = best_parent_rate / (div * tmp_qd);
+ tmp_diff = abs(rate - tmp_rate);
+
+ if (best_diff < 0 || best_diff > tmp_diff) {
+ *parent_rate = best_parent_rate;
+ best_rate = tmp_rate;
+ best_diff = tmp_diff;
+ }
+ }
+
+ pr_debug("A PLL/PAD: %s, best_rate = %ld, best_parent_rate = %lu\n",
+ __func__, best_rate, best_parent_rate);
+
+ return best_rate;
+}
+
+static long clk_audio_pll_pmc_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct clk_hw *pclk = clk_hw_get_parent(hw);
+ long best_rate = -EINVAL;
+ unsigned long best_parent_rate = 0;
+ u32 tmp_qd = 0, div;
+ long tmp_rate;
+ int tmp_diff;
+ int best_diff = -1;
+
+ pr_debug("A PLL/PMC: %s, rate = %lu (parent_rate = %lu)\n", __func__,
+ rate, *parent_rate);
+
+ for (div = 1; div <= AUDIO_PLL_QDPMC_MAX; div++) {
+ best_parent_rate = clk_round_rate(pclk->clk, rate * div);
+ tmp_rate = best_parent_rate / div;
+ tmp_diff = abs(rate - tmp_rate);
+
+ if (best_diff < 0 || best_diff > tmp_diff) {
+ *parent_rate = best_parent_rate;
+ best_rate = tmp_rate;
+ best_diff = tmp_diff;
+ tmp_qd = div;
+ }
+ }
+
+ pr_debug("A PLL/PMC: %s, best_rate = %ld, best_parent_rate = %lu (qd = %d)\n",
+ __func__, best_rate, *parent_rate, tmp_qd - 1);
+
+ return best_rate;
+}
+
+static int clk_audio_pll_frac_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_audio_frac *frac = to_clk_audio_frac(hw);
+ unsigned long fracr, nd;
+ int ret;
+
+ pr_debug("A PLL: %s, rate = %lu (parent_rate = %lu)\n", __func__, rate,
+ parent_rate);
+
+ if (rate < AUDIO_PLL_FOUT_MIN || rate > AUDIO_PLL_FOUT_MAX)
+ return -EINVAL;
+
+ ret = clk_audio_pll_frac_compute_frac(rate, parent_rate, &nd, &fracr);
+ if (ret)
+ return ret;
+
+ frac->nd = nd;
+ frac->fracr = fracr;
+
+ return 0;
+}
+
+static int clk_audio_pll_pad_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_audio_pad *apad_ck = to_clk_audio_pad(hw);
+ u8 tmp_div;
+
+ pr_debug("A PLL/PAD: %s, rate = %lu (parent_rate = %lu)\n", __func__,
+ rate, parent_rate);
+
+ if (!rate)
+ return -EINVAL;
+
+ tmp_div = parent_rate / rate;
+ if (tmp_div % 3 == 0) {
+ apad_ck->qdaudio = tmp_div / 3;
+ apad_ck->div = 3;
+ } else {
+ apad_ck->qdaudio = tmp_div / 2;
+ apad_ck->div = 2;
+ }
+
+ return 0;
+}
+
+static int clk_audio_pll_pmc_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_audio_pmc *apmc_ck = to_clk_audio_pmc(hw);
+
+ if (!rate)
+ return -EINVAL;
+
+ pr_debug("A PLL/PMC: %s, rate = %lu (parent_rate = %lu)\n", __func__,
+ rate, parent_rate);
+
+ apmc_ck->qdpmc = parent_rate / rate - 1;
+
+ return 0;
+}
+
+static const struct clk_ops audio_pll_frac_ops = {
+ .enable = clk_audio_pll_frac_enable,
+ .disable = clk_audio_pll_frac_disable,
+ .recalc_rate = clk_audio_pll_frac_recalc_rate,
+ .round_rate = clk_audio_pll_frac_round_rate,
+ .set_rate = clk_audio_pll_frac_set_rate,
+};
+
+static const struct clk_ops audio_pll_pad_ops = {
+ .enable = clk_audio_pll_pad_enable,
+ .disable = clk_audio_pll_pad_disable,
+ .recalc_rate = clk_audio_pll_pad_recalc_rate,
+ .round_rate = clk_audio_pll_pad_round_rate,
+ .set_rate = clk_audio_pll_pad_set_rate,
+};
+
+static const struct clk_ops audio_pll_pmc_ops = {
+ .enable = clk_audio_pll_pmc_enable,
+ .disable = clk_audio_pll_pmc_disable,
+ .recalc_rate = clk_audio_pll_pmc_recalc_rate,
+ .round_rate = clk_audio_pll_pmc_round_rate,
+ .set_rate = clk_audio_pll_pmc_set_rate,
+};
+
+static int of_sama5d2_clk_audio_pll_setup(struct device_node *np,
+ struct clk_init_data *init,
+ struct clk_hw *hw,
+ struct regmap **clk_audio_regmap)
+{
+ struct regmap *regmap;
+ const char *parent_names[1];
+ int ret;
+
+ regmap = syscon_node_to_regmap(of_get_parent(np));
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+
+ init->name = np->name;
+ of_clk_parent_fill(np, parent_names, 1);
+ init->parent_names = parent_names;
+ init->num_parents = 1;
+
+ hw->init = init;
+ *clk_audio_regmap = regmap;
+
+ ret = clk_hw_register(NULL, hw);
+ if (ret)
+ return ret;
+
+ return of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
+}
+
+static void __init of_sama5d2_clk_audio_pll_frac_setup(struct device_node *np)
+{
+ struct clk_audio_frac *frac_ck;
+ struct clk_init_data init = {};
+
+ frac_ck = kzalloc(sizeof(*frac_ck), GFP_KERNEL);
+ if (!frac_ck)
+ return;
+
+ init.ops = &audio_pll_frac_ops;
+ init.flags = CLK_SET_RATE_GATE;
+
+ if (of_sama5d2_clk_audio_pll_setup(np, &init, &frac_ck->hw,
+ &frac_ck->regmap))
+ kfree(frac_ck);
+}
+
+static void __init of_sama5d2_clk_audio_pll_pad_setup(struct device_node *np)
+{
+ struct clk_audio_pad *apad_ck;
+ struct clk_init_data init = {};
+
+ apad_ck = kzalloc(sizeof(*apad_ck), GFP_KERNEL);
+ if (!apad_ck)
+ return;
+
+ init.ops = &audio_pll_pad_ops;
+ init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
+ CLK_SET_RATE_PARENT;
+
+ if (of_sama5d2_clk_audio_pll_setup(np, &init, &apad_ck->hw,
+ &apad_ck->regmap))
+ kfree(apad_ck);
+}
+
+static void __init of_sama5d2_clk_audio_pll_pmc_setup(struct device_node *np)
+{
+ struct clk_audio_pad *apmc_ck;
+ struct clk_init_data init = {};
+
+ apmc_ck = kzalloc(sizeof(*apmc_ck), GFP_KERNEL);
+ if (!apmc_ck)
+ return;
+
+ init.ops = &audio_pll_pmc_ops;
+ init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
+ CLK_SET_RATE_PARENT;
+
+ if (of_sama5d2_clk_audio_pll_setup(np, &init, &apmc_ck->hw,
+ &apmc_ck->regmap))
+ kfree(apmc_ck);
+}
+
+CLK_OF_DECLARE(of_sama5d2_clk_audio_pll_frac_setup,
+ "atmel,sama5d2-clk-audio-pll-frac",
+ of_sama5d2_clk_audio_pll_frac_setup);
+CLK_OF_DECLARE(of_sama5d2_clk_audio_pll_pad_setup,
+ "atmel,sama5d2-clk-audio-pll-pad",
+ of_sama5d2_clk_audio_pll_pad_setup);
+CLK_OF_DECLARE(of_sama5d2_clk_audio_pll_pmc_setup,
+ "atmel,sama5d2-clk-audio-pll-pmc",
+ of_sama5d2_clk_audio_pll_pmc_setup);
diff --git a/include/linux/clk/at91_pmc.h b/include/linux/clk/at91_pmc.h
index 17f413b..6aca5ce 100644
--- a/include/linux/clk/at91_pmc.h
+++ b/include/linux/clk/at91_pmc.h
@@ -185,4 +185,29 @@
#define AT91_PMC_PCR_EN (0x1 << 28) /* Enable */
#define AT91_PMC_PCR_GCKEN (0x1 << 29) /* GCK Enable */

+#define AT91_PMC_AUDIO_PLL0 0x14c
+#define AT91_PMC_AUDIO_PLL_PLLEN (1 << 0)
+#define AT91_PMC_AUDIO_PLL_PADEN (1 << 1)
+#define AT91_PMC_AUDIO_PLL_PMCEN (1 << 2)
+#define AT91_PMC_AUDIO_PLL_RESETN (1 << 3)
+#define AT91_PMC_AUDIO_PLL_ND_OFFSET 8
+#define AT91_PMC_AUDIO_PLL_ND_MASK (0x7f << AT91_PMC_AUDIO_PLL_ND_OFFSET)
+#define AT91_PMC_AUDIO_PLL_ND(n) ((n) << AT91_PMC_AUDIO_PLL_ND_OFFSET)
+#define AT91_PMC_AUDIO_PLL_QDPMC_OFFSET 16
+#define AT91_PMC_AUDIO_PLL_QDPMC_MASK (0x7f << AT91_PMC_AUDIO_PLL_QDPMC_OFFSET)
+#define AT91_PMC_AUDIO_PLL_QDPMC(n) ((n) << AT91_PMC_AUDIO_PLL_QDPMC_OFFSET)
+
+#define AT91_PMC_AUDIO_PLL1 0x150
+#define AT91_PMC_AUDIO_PLL_FRACR_MASK 0x3fffff
+#define AT91_PMC_AUDIO_PLL_QDPAD_OFFSET 24
+#define AT91_PMC_AUDIO_PLL_QDPAD_MASK (0x7f << AT91_PMC_AUDIO_PLL_QDPAD_OFFSET)
+#define AT91_PMC_AUDIO_PLL_QDPAD(n) ((n) << AT91_PMC_AUDIO_PLL_QDPAD_OFFSET)
+#define AT91_PMC_AUDIO_PLL_QDPAD_DIV_OFFSET AT91_PMC_AUDIO_PLL_QDPAD_OFFSET
+#define AT91_PMC_AUDIO_PLL_QDPAD_DIV_MASK (0x3 << AT91_PMC_AUDIO_PLL_QDPAD_DIV_OFFSET)
+#define AT91_PMC_AUDIO_PLL_QDPAD_DIV(n) ((n) << AT91_PMC_AUDIO_PLL_QDPAD_DIV_OFFSET)
+#define AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV_OFFSET 26
+#define AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV_MAX 0x1f
+#define AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV_MASK (AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV_MAX << AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV_OFFSET)
+#define AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV(n) ((n) << AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV_OFFSET)
+
#endif
--
git-series 0.9.1
Quentin Schulz
2017-07-25 07:37:07 UTC
Permalink
This allows gclk to determine audio_pll rate and set the parent rate
accordingly.

However, there are multiple children clocks that could technically
change the rate of audio_pll (via gck). With the rate locking, the first
consumer to enable the clock will be the one definitely setting the rate
of the clock.

Since audio IPs are most likely to request the same rate, we enforce
that the only clks able to modify gck rate are those of audio IPs.

To remain consistent, we deny other clocks to be children of audio_pll.

Signed-off-by: Quentin Schulz <***@free-electrons.com>
Acked-by: Boris Brezillon <***@free-electrons.com>
---
drivers/clk/at91/clk-generated.c | 63 +++++++++++++++++++++++++++++----
1 file changed, 57 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
index 7260e49..3348136 100644
--- a/drivers/clk/at91/clk-generated.c
+++ b/drivers/clk/at91/clk-generated.c
@@ -26,6 +26,13 @@
#define GENERATED_SOURCE_MAX 6
#define GENERATED_MAX_DIV 255

+#define GCK_ID_SSC0 43
+#define GCK_ID_SSC1 44
+#define GCK_ID_I2S0 54
+#define GCK_ID_I2S1 55
+#define GCK_ID_CLASSD 59
+#define GCK_INDEX_DT_AUDIO_PLL 5
+
struct clk_generated {
struct clk_hw hw;
struct regmap *regmap;
@@ -34,6 +41,7 @@ struct clk_generated {
u32 id;
u32 gckdiv;
u8 parent_id;
+ bool audio_pll_allowed;
};

#define to_clk_generated(hw) \
@@ -126,15 +134,14 @@ static int clk_generated_determine_rate(struct clk_hw *hw,
{
struct clk_generated *gck = to_clk_generated(hw);
struct clk_hw *parent = NULL;
+ struct clk_rate_request req_parent = *req;
long best_rate = -EINVAL;
- unsigned long min_rate;
+ unsigned long min_rate, parent_rate;
int best_diff = -1;
int i;
+ u32 div;

- for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
- u32 div;
- unsigned long parent_rate;
-
+ for (i = 0; i < clk_hw_get_num_parents(hw) - 1; i++) {
parent = clk_hw_get_parent_by_index(hw, i);
if (!parent)
continue;
@@ -150,11 +157,38 @@ static int clk_generated_determine_rate(struct clk_hw *hw,
clk_generated_best_diff(req, parent, parent_rate, div,
&best_diff, &best_rate);

+ if (!best_diff)
+ break;
+ }
+
+ /*
+ * The audio_pll rate can be modified, unlike the five others clocks
+ * that should never be altered.
+ * The audio_pll can technically be used by multiple consumers. However,
+ * with the rate locking, the first consumer to enable to clock will be
+ * the one definitely setting the rate of the clock.
+ * Since audio IPs are most likely to request the same rate, we enforce
+ * that the only clks able to modify gck rate are those of audio IPs.
+ */
+
+ if (!gck->audio_pll_allowed)
+ goto end;
+
+ parent = clk_hw_get_parent_by_index(hw, GCK_INDEX_DT_AUDIO_PLL);
+ if (!parent)
+ goto end;
+
+ for (div = 1; div < GENERATED_MAX_DIV + 2; div++) {
+ req_parent.rate = req->rate * div;
+ __clk_determine_rate(parent, &req_parent);
+ clk_generated_best_diff(req, parent, req_parent.rate, div,
+ &best_diff, &best_rate);

if (!best_diff)
break;
}

+end:
pr_debug("GCLK: %s, best_rate = %ld, parent clk: %s @ %ld\n",
__func__, best_rate,
__clk_get_name((req->best_parent_hw)->clk),
@@ -264,7 +298,8 @@ at91_clk_register_generated(struct regmap *regmap, spinlock_t *lock,
init.ops = &generated_ops;
init.parent_names = parent_names;
init.num_parents = num_parents;
- init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
+ init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
+ CLK_SET_RATE_PARENT;

gck->id = id;
gck->hw.init = &init;
@@ -296,6 +331,7 @@ static void __init of_sama5d2_clk_generated_setup(struct device_node *np)
struct device_node *gcknp;
struct clk_range range = CLK_RANGE(0, 0);
struct regmap *regmap;
+ struct clk_generated *gck;

num_parents = of_clk_get_parent_count(np);
if (num_parents == 0 || num_parents > GENERATED_SOURCE_MAX)
@@ -327,6 +363,21 @@ static void __init of_sama5d2_clk_generated_setup(struct device_node *np)
hw = at91_clk_register_generated(regmap, &pmc_pcr_lock, name,
parent_names, num_parents,
id, &range);
+
+ gck = to_clk_generated(hw);
+
+ if (of_device_is_compatible(np,
+ "atmel,sama5d2-clk-generated")) {
+ if (gck->id == GCK_ID_SSC0 || gck->id == GCK_ID_SSC1 ||
+ gck->id == GCK_ID_I2S0 || gck->id == GCK_ID_I2S1 ||
+ gck->id == GCK_ID_CLASSD)
+ gck->audio_pll_allowed = true;
+ else
+ gck->audio_pll_allowed = false;
+ } else {
+ gck->audio_pll_allowed = false;
+ }
+
if (IS_ERR(hw))
continue;
--
git-series 0.9.1
Nicolas Ferre
2017-07-25 15:37:37 UTC
Permalink
Post by Quentin Schulz
This allows gclk to determine audio_pll rate and set the parent rate
accordingly.
However, there are multiple children clocks that could technically
change the rate of audio_pll (via gck). With the rate locking, the first
consumer to enable the clock will be the one definitely setting the rate
of the clock.
Since audio IPs are most likely to request the same rate, we enforce
that the only clks able to modify gck rate are those of audio IPs.
To remain consistent, we deny other clocks to be children of audio_pll.
---
drivers/clk/at91/clk-generated.c | 63 +++++++++++++++++++++++++++++----
1 file changed, 57 insertions(+), 6 deletions(-)
diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
index 7260e49..3348136 100644
--- a/drivers/clk/at91/clk-generated.c
+++ b/drivers/clk/at91/clk-generated.c
@@ -26,6 +26,13 @@
#define GENERATED_SOURCE_MAX 6
#define GENERATED_MAX_DIV 255
+#define GCK_ID_SSC0 43
+#define GCK_ID_SSC1 44
+#define GCK_ID_I2S0 54
+#define GCK_ID_I2S1 55
+#define GCK_ID_CLASSD 59
+#define GCK_INDEX_DT_AUDIO_PLL 5
+
struct clk_generated {
struct clk_hw hw;
struct regmap *regmap;
@@ -34,6 +41,7 @@ struct clk_generated {
u32 id;
u32 gckdiv;
u8 parent_id;
+ bool audio_pll_allowed;
};
#define to_clk_generated(hw) \
@@ -126,15 +134,14 @@ static int clk_generated_determine_rate(struct clk_hw *hw,
{
struct clk_generated *gck = to_clk_generated(hw);
struct clk_hw *parent = NULL;
+ struct clk_rate_request req_parent = *req;
long best_rate = -EINVAL;
- unsigned long min_rate;
+ unsigned long min_rate, parent_rate;
int best_diff = -1;
int i;
+ u32 div;
- for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
- u32 div;
- unsigned long parent_rate;
-
+ for (i = 0; i < clk_hw_get_num_parents(hw) - 1; i++) {
parent = clk_hw_get_parent_by_index(hw, i);
if (!parent)
continue;
@@ -150,11 +157,38 @@ static int clk_generated_determine_rate(struct clk_hw *hw,
clk_generated_best_diff(req, parent, parent_rate, div,
&best_diff, &best_rate);
+ if (!best_diff)
+ break;
+ }
+
+ /*
+ * The audio_pll rate can be modified, unlike the five others clocks
+ * that should never be altered.
+ * The audio_pll can technically be used by multiple consumers. However,
+ * with the rate locking, the first consumer to enable to clock will be
+ * the one definitely setting the rate of the clock.
+ * Since audio IPs are most likely to request the same rate, we enforce
+ * that the only clks able to modify gck rate are those of audio IPs.
+ */
+
+ if (!gck->audio_pll_allowed)
+ goto end;
+
+ parent = clk_hw_get_parent_by_index(hw, GCK_INDEX_DT_AUDIO_PLL);
+ if (!parent)
+ goto end;
+
+ for (div = 1; div < GENERATED_MAX_DIV + 2; div++) {
+ req_parent.rate = req->rate * div;
+ __clk_determine_rate(parent, &req_parent);
+ clk_generated_best_diff(req, parent, req_parent.rate, div,
+ &best_diff, &best_rate);
if (!best_diff)
break;
}
__func__, best_rate,
__clk_get_name((req->best_parent_hw)->clk),
@@ -264,7 +298,8 @@ at91_clk_register_generated(struct regmap *regmap, spinlock_t *lock,
init.ops = &generated_ops;
init.parent_names = parent_names;
init.num_parents = num_parents;
- init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
+ init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
+ CLK_SET_RATE_PARENT;
gck->id = id;
gck->hw.init = &init;
@@ -296,6 +331,7 @@ static void __init of_sama5d2_clk_generated_setup(struct device_node *np)
struct device_node *gcknp;
struct clk_range range = CLK_RANGE(0, 0);
struct regmap *regmap;
+ struct clk_generated *gck;
num_parents = of_clk_get_parent_count(np);
if (num_parents == 0 || num_parents > GENERATED_SOURCE_MAX)
@@ -327,6 +363,21 @@ static void __init of_sama5d2_clk_generated_setup(struct device_node *np)
hw = at91_clk_register_generated(regmap, &pmc_pcr_lock, name,
parent_names, num_parents,
id, &range);
+
+ gck = to_clk_generated(hw);
+
+ if (of_device_is_compatible(np,
+ "atmel,sama5d2-clk-generated")) {
+ if (gck->id == GCK_ID_SSC0 || gck->id == GCK_ID_SSC1 ||
+ gck->id == GCK_ID_I2S0 || gck->id == GCK_ID_I2S1 ||
+ gck->id == GCK_ID_CLASSD)
+ gck->audio_pll_allowed = true;
+ else
+ gck->audio_pll_allowed = false;
+ } else {
+ gck->audio_pll_allowed = false;
+ }
+
if (IS_ERR(hw))
continue;
--
Nicolas Ferre
Nicolas Ferre
2017-07-25 15:44:19 UTC
Permalink
This patch series adds support for the audio PLLs and enables ClassD that
can be found in ATMEL Sama5d2 SoC.
There are two audio PLLs (PMC and PAD) that shares the same parent (FRAC).
FRAC can output between 620 and 700MHz and only multiply the rate of its
parent. The two audio PLLs then divide the FRAC rate to best match the
asked rate.
I basically took an old patch series posted by Nicolas on December, 6th
2016[1][2][3] and the comments Boris did on the first version[4] Nicolas
sent on July, 15th 2015.
I also fixed the function used to compute the divisors, removed useless
spinlocks and added a range to the audio frac PLL to stay within vendor's
supported range. Clocks that are children of gclk (generated-clk) are now
able to propagate rate to the audio PLL clocks when needed.
However, there are multiple children clocks that could technically
change the rate of audio_pll (via gck). With the rate locking introduced
in Jerome Brunet's patch series[5], the first consumer to enable the clock
will be the one definitely setting the rate of the clock. Without the rate
locking, the last consumer to set the rate will be able to mess with the
rate.
Since audio IPs are most likely to request the same rate, we enforce
that the only clks able to modify gck rate are those of audio IPs.
To remain consistent, we deny other clocks to be children of audio_pll.
Quentin,

Thanks for having revived this series. Everything's okay on my side for
this v4. I think that my tag isn't missing from any patch of this
series. Now we surely need to define which path it must take...

Best regards,
- initialized the clk_init_data structure,
- switched to of_clk_parent_fill instead of manually setting
parent_names,
- removed include of clkdev.h in favor of slab.h,
- removed unnecessary second cast in operation,
- used clamp instead of two conditions,
- removed dependency on clock-output-names, the name is gotten from DT
node,
- merged all three drivers for audio PLLs (FRAC, PMC, PAD) into one,
- added a flag per generated clock to know which one is allowed to
modify audio_pll rate,
- set the flag in setup function depending on the compatible and the
clock ID,
- split big patch containing dt-binding, pll drivers and classd
modifications,
- removed unused AUDIO_PLL_*FOUT* defines from clk-audio-pll-pmc,
- added conditions for audio pll rate setting restriction for SSC and
I2S,
- renamed all mentions of ACLK to GCLK in classD driver,
Thanks,
Quentin
[1] https://patchwork.kernel.org/patch/9462351/
[2] https://patchwork.kernel.org/patch/9462347/
[3] https://patchwork.kernel.org/patch/9462349/
[4] https://www.spinics.net/lists/arm-kernel/msg436120.html
[5] http://www.spinics.net/lists/linux-clk/msg17927.html
ARM: dts: at91: sama5d2: add classd nodes
ARM: dts: at91: sama5d2_xplained: add pin muxing and enable classd
clk: at91: clk-generated: remove useless divisor loop
dt-bindings: clk: at91: add audio plls to the compatible list
clk: at91: add audio pll clock drivers
clk: at91: clk-generated: create function to find best_diff
clk: at91: clk-generated: make gclk determine audio_pll rate
ASoC: atmel-classd: remove aclk clock from DT binding
ASoC: atmel-classd: remove aclk clock
Documentation/devicetree/bindings/clock/at91-clock.txt | 10 +-
Documentation/devicetree/bindings/sound/atmel-classd.txt | 9 +-
arch/arm/boot/dts/at91-sama5d2_xplained.dts | 16 +-
arch/arm/boot/dts/sama5d2.dtsi | 39 +-
arch/arm/mach-at91/Kconfig | 4 +-
drivers/clk/at91/Makefile | 1 +-
drivers/clk/at91/clk-audio-pll.c | 531 ++++++++-
drivers/clk/at91/clk-generated.c | 101 +-
include/linux/clk/at91_pmc.h | 25 +-
sound/soc/atmel/atmel-classd.c | 47 +-
10 files changed, 724 insertions(+), 59 deletions(-)
create mode 100644 drivers/clk/at91/clk-audio-pll.c
base-commit: 047a0f692a9354d730dad30f25e1ebd8437b32b1
--
Nicolas Ferre
Nicolas Ferre
2017-07-25 15:45:05 UTC
Permalink
Post by Quentin Schulz
This new clock driver set allows to have a fractional divided clock that
would generate a precise clock particularly suitable for audio
applications.
The main audio pll clock has two children clocks: one that is connected
to the PMC, the other that can directly drive a pad. As these two routes
have different enable bits and different dividers and divider formulas,
they are handled by two different drivers.
This adds the audio plls (frac, pad and pmc) to the compatible list of
at91 clocks in DT binding.
---
Documentation/devicetree/bindings/clock/at91-clock.txt | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/Documentation/devicetree/bindings/clock/at91-clock.txt b/Documentation/devicetree/bindings/clock/at91-clock.txt
index 5f3ad65..51c259a 100644
--- a/Documentation/devicetree/bindings/clock/at91-clock.txt
+++ b/Documentation/devicetree/bindings/clock/at91-clock.txt
at91 generated clock
+ at91 audio fractional pll
+
+ at91 audio pll CLK_AUDIO output pin
+
+ "atmel,sama5d2-clk-audio-pll-pmc"
+ at91 audio pll output on AUDIOPLLCLK that feeds the PMC
+ and can be used by peripheral clock or generic clock
+
- reg : defines the IO memory reserved for the SCKC.
- #size-cells : shall be 0 (reg is used to encode clk id).
--
Nicolas Ferre
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