[RFC PATCH 1/3] clk: bd718x7: Clean up the code, no functional changes

[RFC PATCH 1/3] clk: bd718x7: Clean up the code, no functional changes

[Michael Trimarchi]

Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
---
 drivers/clk/clk-bd718x7.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/clk/clk-bd718x7.c b/drivers/clk/clk-bd718x7.c
index ac40b669d60b..04cc0beb67df 100644
--- a/drivers/clk/clk-bd718x7.c
+++ b/drivers/clk/clk-bd718x7.c
@@ -81,27 +81,28 @@ static int bd71837_clk_probe(struct platform_device *pdev)
 	struct bd718xx_clk *c;
 	int rval = -ENOMEM;
 	const char *parent_clk;
+	struct device *dev = &pdev->dev;
 	struct device *parent = pdev->dev.parent;
 	struct clk_init_data init = {
 		.name = "bd718xx-32k-out",
 		.ops = &bd71837_clk_ops,
+		.num_parents = 1,
 	};
 	enum rohm_chip_type chip = platform_get_device_id(pdev)->driver_data;
 
-	c = devm_kzalloc(&pdev->dev, sizeof(*c), GFP_KERNEL);
+	c = devm_kzalloc(dev, sizeof(*c), GFP_KERNEL);
 	if (!c)
 		return -ENOMEM;
 
-	c->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	c->regmap = dev_get_regmap(parent, NULL);
 	if (!c->regmap)
 		return -ENODEV;
 
-	init.num_parents = 1;
 	parent_clk = of_clk_get_parent_name(parent->of_node, 0);
 
 	init.parent_names = &parent_clk;
 	if (!parent_clk) {
-		dev_err(&pdev->dev, "No parent clk found\n");
+		dev_err(dev, "No parent clk found\n");
 		return -EINVAL;
 	}
 	switch (chip) {
@@ -119,7 +120,7 @@ static int bd71837_clk_probe(struct platform_device *pdev)
 		c->mask = CLK_OUT_EN_MASK;
 		break;
 	default:
-		dev_err(&pdev->dev, "Unknown clk chip\n");
+		dev_err(dev, "Unknown clk chip\n");
 		return -EINVAL;
 	}
 	c->pdev = pdev;
@@ -128,15 +129,15 @@ static int bd71837_clk_probe(struct platform_device *pdev)
 	of_property_read_string_index(parent->of_node,
 				      "clock-output-names", 0, &init.name);
 
-	rval = devm_clk_hw_register(&pdev->dev, &c->hw);
+	rval = devm_clk_hw_register(dev, &c->hw);
 	if (rval) {
-		dev_err(&pdev->dev, "failed to register 32K clk");
+		dev_err(dev, "failed to register 32K clk");
 		return rval;
 	}
-	rval = devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get,
+	rval = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
 					   &c->hw);
 	if (rval)
-		dev_err(&pdev->dev, "adding clk provider failed\n");
+		dev_err(dev, "adding clk provider failed\n");
 
 	return rval;
 }
-- 
2.25.1

[RFC PATCH 2/3] clk: bd718x7: Enable the possibility to mark the clock as critical

[Michael Trimarchi]

If the clock is used to generate the osc_32k, we need to mark
as critical. clock-critical has no binding description at the moment
but it's defined in linux kernel

bd71847: pmic@4b {
...
	rohm,reset-snvs-powered;

	#clock-cells = <0>;
	clock-critical = <1>;
	clocks = <&osc_32k 0>;
	clock-output-names = "clk-32k-out";
...
}

Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
---
 drivers/clk/clk-bd718x7.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/clk/clk-bd718x7.c b/drivers/clk/clk-bd718x7.c
index 04cc0beb67df..5088379ec2b7 100644
--- a/drivers/clk/clk-bd718x7.c
+++ b/drivers/clk/clk-bd718x7.c
@@ -83,6 +83,7 @@ static int bd71837_clk_probe(struct platform_device *pdev)
 	const char *parent_clk;
 	struct device *dev = &pdev->dev;
 	struct device *parent = pdev->dev.parent;
+	unsigned long flags;
 	struct clk_init_data init = {
 		.name = "bd718xx-32k-out",
 		.ops = &bd71837_clk_ops,
@@ -100,6 +101,9 @@ static int bd71837_clk_probe(struct platform_device *pdev)
 
 	parent_clk = of_clk_get_parent_name(parent->of_node, 0);
 
+	of_clk_detect_critical(dev->of_node, 0, &flags);
+	init.flags = flags;
+
 	init.parent_names = &parent_clk;
 	if (!parent_clk) {
 		dev_err(dev, "No parent clk found\n");
-- 
2.25.1

[RFC PATCH 3/3] arm64: dts: imx8mn-bsh-smm-s2/pro: Add pmic clock connection

[Michael Trimarchi]

pmic clock is connected to svns_rtc using RTC_XTALI pin so we
need to mark this clock as critical. The clock source even the
wifi/bluetooth chipset

Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
---
 arch/arm64/boot/dts/freescale/imx8mn-bsh-smm-s2-common.dtsi | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mn-bsh-smm-s2-common.dtsi b/arch/arm64/boot/dts/freescale/imx8mn-bsh-smm-s2-common.dtsi
index c11895d9d582..072d2c480f20 100644
--- a/arch/arm64/boot/dts/freescale/imx8mn-bsh-smm-s2-common.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mn-bsh-smm-s2-common.dtsi
@@ -28,6 +28,8 @@ usdhc2_pwrseq: usdhc2-pwrseq {
 		pinctrl-names = "default";
 		pinctrl-0 = <&pinctrl_usdhc2_pwrseq>;
 		reset-gpios = <&gpio4 27 GPIO_ACTIVE_LOW>;
+		clocks = <&bd71847 0>;
+		clock-names = "ext_clock";
 	};
 };
 
@@ -92,6 +94,7 @@ bd71847: pmic@4b {
 		rohm,reset-snvs-powered;
 
 		#clock-cells = <0>;
+		clock-critical = <1>;
 		clocks = <&osc_32k 0>;
 		clock-output-names = "clk-32k-out";
 
@@ -235,6 +238,8 @@ bluetooth {
 		shutdown-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>;
 		device-wakeup-gpios = <&gpio1 18 GPIO_ACTIVE_HIGH>;
 		host-wakeup-gpios = <&gpio1 28 GPIO_ACTIVE_HIGH>;
+		clocks = <&bd71847 0>;
+		clock-names = "lpo";
 		max-speed = <3000000>;
 	};
 };
-- 
2.25.1

Re: [RFC PATCH 2/3] clk: bd718x7: Enable the possibility to mark the clock as critical

[Matti Vaittinen]

Hi Michael,

On 6/5/22 19:57, Michael Trimarchi wrote:
> If the clock is used to generate the osc_32k, we need to mark
> as critical. clock-critical has no binding description at the moment
> but it's defined in linux kernel
> 
> bd71847: pmic@4b {
> ...
> 	rohm,reset-snvs-powered;
> 
> 	#clock-cells = <0>;
> 	clock-critical = <1>;
> 	clocks = <&osc_32k 0>;
> 	clock-output-names = "clk-32k-out";
> ...
> }
> 
> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
> ---
>   drivers/clk/clk-bd718x7.c | 4 ++++

//snip

> @@ -100,6 +101,9 @@ static int bd71837_clk_probe(struct platform_device *pdev)
>   
>   	parent_clk = of_clk_get_parent_name(parent->of_node, 0);
>   
> +	of_clk_detect_critical(dev->of_node, 0, &flags);

Purely judging the kerneldoc for of_clk_detect_critical - you may have 
hard time getting this accepted.

I think you're working on a very valid problem though. Maybe you could 
see if you could align your effort with Marek?

https://lore.kernel.org/all/20220517235919.200375-1-marex@denx.de/T/#m52d6d0831bf43d5f293e35cb27f3021f278d0564

Best Regards
	-- Matti

-- 
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

~~ When things go utterly wrong vim users can always type :help! ~~

Discuss - Estimate - Plan - Report and finally accomplish this:
void do_work(int time) __attribute__ ((const));

Re: [RFC PATCH 1/3] clk: bd718x7: Clean up the code, no functional changes

[Matti Vaittinen]

On 6/5/22 19:57, Michael Trimarchi wrote:
> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
> ---
>   drivers/clk/clk-bd718x7.c | 19 ++++++++++---------
>   1 file changed, 10 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/clk/clk-bd718x7.c b/drivers/clk/clk-bd718x7.c
> index ac40b669d60b..04cc0beb67df 100644
> --- a/drivers/clk/clk-bd718x7.c
> +++ b/drivers/clk/clk-bd718x7.c
> @@ -81,27 +81,28 @@ static int bd71837_clk_probe(struct platform_device *pdev)
>   	struct bd718xx_clk *c;
>   	int rval = -ENOMEM;
>   	const char *parent_clk;
> +	struct device *dev = &pdev->dev;

I am not a fan of assigning pointers to struct members to local 
variables unless they're shortening lines to fit on one row instead of 
using two. Whenever we add such a variable we hide information. After 
that being said - in this particular case the device 'dev' points to is 
quite obvious so I am not completely against the change if other see the 
value.

>   	struct device *parent = pdev->dev.parent;
>   	struct clk_init_data init = {
>   		.name = "bd718xx-32k-out",
>   		.ops = &bd71837_clk_ops,
> +		.num_parents = 1,

I like this. Thanks.

>   	};

Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>

Best Regards
	-- Matti

-- 
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

~~ When things go utterly wrong vim users can always type :help! ~~

Discuss - Estimate - Plan - Report and finally accomplish this:
void do_work(int time) __attribute__ ((const));

Re: [RFC PATCH 2/3] clk: bd718x7: Enable the possibility to mark the clock as critical

[Michael Nazzareno Trimarchi]

Hi

On Mon, Jun 6, 2022 at 7:26 AM Matti Vaittinen <mazziesaccount@gmail.com> wrote:
>
> Hi Michael,
>
> On 6/5/22 19:57, Michael Trimarchi wrote:
> > If the clock is used to generate the osc_32k, we need to mark
> > as critical. clock-critical has no binding description at the moment
> > but it's defined in linux kernel
> >
> > bd71847: pmic@4b {
> > ...
> >       rohm,reset-snvs-powered;
> >
> >       #clock-cells = <0>;
> >       clock-critical = <1>;
> >       clocks = <&osc_32k 0>;
> >       clock-output-names = "clk-32k-out";
> > ...
> > }
> >
> > Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
> > ---
> >   drivers/clk/clk-bd718x7.c | 4 ++++
>
> //snip
>
> > @@ -100,6 +101,9 @@ static int bd71837_clk_probe(struct platform_device *pdev)
> >
> >       parent_clk = of_clk_get_parent_name(parent->of_node, 0);
> >
> > +     of_clk_detect_critical(dev->of_node, 0, &flags);
>
> Purely judging the kerneldoc for of_clk_detect_critical - you may have
> hard time getting this accepted.
>

This is the reason for RFC. I have already seen the usage of this in

ainline/master:drivers/clk/st/clk-flexgen.c:
of_clk_detect_critical(np, i, &flex_flags);
mainline/master:drivers/clk/st/clkgen-fsyn.c:
of_clk_detect_critical(np, fschan, &flags);
mainline/master:drivers/clk/st/clkgen-pll.c:
of_clk_detect_critical(np, 0, &pll_flags);
mainline/master:drivers/clk/st/clkgen-pll.c:
of_clk_detect_critical(np, odf, &odf_flags);

> I think you're working on a very valid problem though. Maybe you could
> see if you could align your effort with Marek?
>
> https://lore.kernel.org/all/20220517235919.200375-1-marex@denx.de/T/#m52d6d0831bf43d5f293e35cb27f3021f278d0564
>

I have seen the Marek patcheset now. I don't know if they works anyway
for a clock that is a part of MFD controller

Michael

> Best Regards
>         -- Matti
>
> --
> Matti Vaittinen
> Linux kernel developer at ROHM Semiconductors
> Oulu Finland
>
> ~~ When things go utterly wrong vim users can always type :help! ~~
>
> Discuss - Estimate - Plan - Report and finally accomplish this:
> void do_work(int time) __attribute__ ((const));



-- 
Michael Nazzareno Trimarchi
Co-Founder & Chief Executive Officer
M. +39 347 913 2170
michael@amarulasolutions.com
__________________________________

Amarula Solutions BV
Joop Geesinkweg 125, 1114 AB, Amsterdam, NL
T. +31 (0)85 111 9172
info@amarulasolutions.com
www.amarulasolutions.com