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* [PATCH 1/3] ARM: dts: imx7s: add snvs clock to pwrkey
@ 2020-01-30 20:45 André Draszik
  2020-01-30 20:45 ` [PATCH 2/3] Input: snvs_pwrkey - enable snvs clock as needed André Draszik
                   ` (3 more replies)
  0 siblings, 4 replies; 13+ messages in thread
From: André Draszik @ 2020-01-30 20:45 UTC (permalink / raw)
  To: linux-kernel
  Cc: André Draszik, Anson Huang, Dmitry Torokhov,
	Horia Geantă,
	Aymen Sghaier, Herbert Xu, David S. Miller, Rob Herring,
	Mark Rutland, linux-crypto, devicetree, linux-input

On i.MX7, the SNVS requires a clock. This is similar to the clock
bound to the SNVS RTC node, but if the SNVS RTC driver isn't enabled,
then SNVS doesn't work, and as such the pwrkey driver doesn't
work (i.e. hangs the kernel, as the clock isn't enabled).

Also see commit ec2a844ef7c1
("ARM: dts: imx7s: add snvs rtc clock")
for a similar fix.

Signed-off-by: André Draszik <git@andred.net>
Cc: Anson Huang <Anson.Huang@nxp.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: "Horia Geantă" <horia.geanta@nxp.com>
Cc: Aymen Sghaier <aymen.sghaier@nxp.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-crypto@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-input@vger.kernel.org
---
 .../devicetree/bindings/crypto/fsl-sec4.txt     | 17 +++++++++++++++++
 arch/arm/boot/dts/imx7s.dtsi                    |  2 ++
 2 files changed, 19 insertions(+)

diff --git a/Documentation/devicetree/bindings/crypto/fsl-sec4.txt b/Documentation/devicetree/bindings/crypto/fsl-sec4.txt
index 2fe245ca816a..755c2838d658 100644
--- a/Documentation/devicetree/bindings/crypto/fsl-sec4.txt
+++ b/Documentation/devicetree/bindings/crypto/fsl-sec4.txt
@@ -449,6 +449,19 @@ System ON/OFF key driver
       Value type: <phandle>
       Definition: this is phandle to the register map node.
 
+   - clocks
+      Usage: optional, required if SNVS LP requires explicit
+          enablement of clocks
+      Value type: <prop_encoded-array>
+      Definition:  a clock specifier describing the clock required for
+          enabling and disabling SNVS LP RTC.
+
+   - clock-names
+      Usage: optional, required if SNVS LP requires explicit
+          enablement of clocks
+      Value type: <string>
+      Definition: clock name string should be "snvs-pwrkey".
+
 EXAMPLE:
 	snvs-pwrkey@020cc000 {
 		compatible = "fsl,sec-v4.0-pwrkey";
@@ -456,6 +469,8 @@ EXAMPLE:
 		interrupts = <0 4 0x4>
 	        linux,keycode = <116>; /* KEY_POWER */
 		wakeup-source;
+		clocks = <&clks IMX7D_SNVS_CLK>;
+		clock-names = "snvs-pwrkey";
 	};
 
 =====================================================================
@@ -547,6 +562,8 @@ FULL EXAMPLE
 			interrupts = <0 4 0x4>;
 			linux,keycode = <116>; /* KEY_POWER */
 			wakeup-source;
+			clocks = <&clks IMX7D_SNVS_CLK>;
+			clock-names = "snvs-pwrkey";
 		};
 	};
 
diff --git a/arch/arm/boot/dts/imx7s.dtsi b/arch/arm/boot/dts/imx7s.dtsi
index 1b812f4e7453..6240a6f58048 100644
--- a/arch/arm/boot/dts/imx7s.dtsi
+++ b/arch/arm/boot/dts/imx7s.dtsi
@@ -614,6 +614,8 @@
 					linux,keycode = <KEY_POWER>;
 					wakeup-source;
 					status = "disabled";
+					clocks = <&clks IMX7D_SNVS_CLK>;
+					clock-names = "snvs-pwrkey";
 				};
 			};
 
-- 
2.23.0.rc1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH 2/3] Input: snvs_pwrkey - enable snvs clock as needed
  2020-01-30 20:45 [PATCH 1/3] ARM: dts: imx7s: add snvs clock to pwrkey André Draszik
@ 2020-01-30 20:45 ` André Draszik
  2020-02-07  8:10   ` Horia Geanta
  2020-01-30 20:45 ` [PATCH 3/3] Input: snvs_pwrkey - only IRQ_HANDLED for our own events André Draszik
                   ` (2 subsequent siblings)
  3 siblings, 1 reply; 13+ messages in thread
From: André Draszik @ 2020-01-30 20:45 UTC (permalink / raw)
  To: linux-kernel
  Cc: André Draszik, Anson Huang, Dmitry Torokhov,
	Horia Geantă,
	Aymen Sghaier, Herbert Xu, David S. Miller, Rob Herring,
	Mark Rutland, linux-crypto, devicetree, linux-input

At the moment, enabling this driver without the SNVS RTC driver
being active will hang the kernel as soon as the power button
is pressed.

The reason is that in that case the SNVS isn't enabled, and
any attempt to read the SNVS registers will simply hang forever.

Ensure the clock is enabled (during the interrupt handler) to
make this driver work.

Also see commit 7f8993995410 ("drivers/rtc/rtc-snvs: add clock support")
and commit edb190cb1734
("rtc: snvs: make sure clock is enabled for interrupt handle")
for similar updates to the snvs rtc driver.

Signed-off-by: André Draszik <git@andred.net>
Cc: Anson Huang <Anson.Huang@nxp.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: "Horia Geantă" <horia.geanta@nxp.com>
Cc: Aymen Sghaier <aymen.sghaier@nxp.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-crypto@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-input@vger.kernel.org
---
 drivers/input/keyboard/snvs_pwrkey.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/input/keyboard/snvs_pwrkey.c b/drivers/input/keyboard/snvs_pwrkey.c
index 2f5e3ab5ed63..c29711d8735c 100644
--- a/drivers/input/keyboard/snvs_pwrkey.c
+++ b/drivers/input/keyboard/snvs_pwrkey.c
@@ -16,6 +16,7 @@
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
 #include <linux/pm_wakeirq.h>
+#include <linux/clk.h>
 #include <linux/mfd/syscon.h>
 #include <linux/regmap.h>
 
@@ -38,6 +39,7 @@ struct pwrkey_drv_data {
 	int wakeup;
 	struct timer_list check_timer;
 	struct input_dev *input;
+	struct clk *clk;
 	u8 minor_rev;
 };
 
@@ -72,6 +74,9 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
 	struct input_dev *input = pdata->input;
 	u32 lp_status;
 
+	if (pdata->clk)
+		clk_enable(pdata->clk);
+
 	pm_wakeup_event(input->dev.parent, 0);
 
 	regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
@@ -96,6 +101,9 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
 	/* clear SPO status */
 	regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
 
+	if (pdata->clk)
+		clk_disable(pdata->clk);
+
 	return IRQ_HANDLED;
 }
 
@@ -140,6 +148,25 @@ static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
 	if (pdata->irq < 0)
 		return -EINVAL;
 
+	pdata->clk = devm_clk_get(&pdev->dev, "snvs-pwrkey");
+	if (IS_ERR(pdata->clk)) {
+		pdata->clk = NULL;
+	} else {
+		error = clk_prepare_enable(pdata->clk);
+		if (error) {
+			dev_err(&pdev->dev,
+				"Could not prepare or enable the snvs clock\n");
+			return error;
+		}
+		error = devm_add_action_or_reset(&pdev->dev,
+				(void(*)(void *))clk_disable_unprepare,
+				pdata->clk);
+		if (error) {
+			dev_err(&pdev->dev, "failed to add reset action on 'snvs-pwrkey'");
+			return error;
+		}
+	}
+
 	regmap_read(pdata->snvs, SNVS_HPVIDR1_REG, &vid);
 	pdata->minor_rev = vid & 0xff;
 
-- 
2.23.0.rc1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH 3/3] Input: snvs_pwrkey - only IRQ_HANDLED for our own events
  2020-01-30 20:45 [PATCH 1/3] ARM: dts: imx7s: add snvs clock to pwrkey André Draszik
  2020-01-30 20:45 ` [PATCH 2/3] Input: snvs_pwrkey - enable snvs clock as needed André Draszik
@ 2020-01-30 20:45 ` André Draszik
  2020-02-06 18:30 ` [PATCH 1/3] ARM: dts: imx7s: add snvs clock to pwrkey Rob Herring
  2020-02-07  7:36 ` Horia Geanta
  3 siblings, 0 replies; 13+ messages in thread
From: André Draszik @ 2020-01-30 20:45 UTC (permalink / raw)
  To: linux-kernel
  Cc: André Draszik, Anson Huang, Dmitry Torokhov,
	Alessandro Zummo, Alexandre Belloni, linux-input

The snvs_pwrkey shares the SNVS LPSR status register with the snvs_rtc.

This driver here should only return IRQ_HANDLED if the status register
indicates that the event we're handling in the irq handler was genuinely
intended for this driver. Otheriwse the interrupt subsystem will
assume the interrupt was handled successfully even though it wasn't
at all.

Signed-off-by: André Draszik <git@andred.net>
Cc: Anson Huang <Anson.Huang@nxp.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: linux-input@vger.kernel.org
---
 drivers/input/keyboard/snvs_pwrkey.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/input/keyboard/snvs_pwrkey.c b/drivers/input/keyboard/snvs_pwrkey.c
index c29711d8735c..9f51bcc5b5fd 100644
--- a/drivers/input/keyboard/snvs_pwrkey.c
+++ b/drivers/input/keyboard/snvs_pwrkey.c
@@ -80,7 +80,9 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
 	pm_wakeup_event(input->dev.parent, 0);
 
 	regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
-	if (lp_status & SNVS_LPSR_SPO) {
+	lp_status &= SNVS_LPSR_SPO;
+
+	if (lp_status) {
 		if (pdata->minor_rev == 0) {
 			/*
 			 * The first generation i.MX6 SoCs only sends an
@@ -96,15 +98,14 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
 			mod_timer(&pdata->check_timer,
 			          jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
 		}
-	}
 
-	/* clear SPO status */
-	regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
+		regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
+	}
 
 	if (pdata->clk)
 		clk_disable(pdata->clk);
 
-	return IRQ_HANDLED;
+	return lp_status ? IRQ_HANDLED : IRQ_NONE;
 }
 
 static void imx_snvs_pwrkey_act(void *pdata)
-- 
2.23.0.rc1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH 1/3] ARM: dts: imx7s: add snvs clock to pwrkey
  2020-01-30 20:45 [PATCH 1/3] ARM: dts: imx7s: add snvs clock to pwrkey André Draszik
  2020-01-30 20:45 ` [PATCH 2/3] Input: snvs_pwrkey - enable snvs clock as needed André Draszik
  2020-01-30 20:45 ` [PATCH 3/3] Input: snvs_pwrkey - only IRQ_HANDLED for our own events André Draszik
@ 2020-02-06 18:30 ` Rob Herring
  2020-02-07  7:36 ` Horia Geanta
  3 siblings, 0 replies; 13+ messages in thread
From: Rob Herring @ 2020-02-06 18:30 UTC (permalink / raw)
  To: André Draszik
  Cc: linux-kernel, André Draszik, Anson Huang, Dmitry Torokhov,
	Horia Geantă,
	Aymen Sghaier, Herbert Xu, David S. Miller, Mark Rutland,
	linux-crypto, devicetree, linux-input

On Thu, 30 Jan 2020 20:45:14 +0000, =?UTF-8?q?Andr=C3=A9=20Draszik?= wrote:
> On i.MX7, the SNVS requires a clock. This is similar to the clock
> bound to the SNVS RTC node, but if the SNVS RTC driver isn't enabled,
> then SNVS doesn't work, and as such the pwrkey driver doesn't
> work (i.e. hangs the kernel, as the clock isn't enabled).
> 
> Also see commit ec2a844ef7c1
> ("ARM: dts: imx7s: add snvs rtc clock")
> for a similar fix.
> 
> Signed-off-by: André Draszik <git@andred.net>
> Cc: Anson Huang <Anson.Huang@nxp.com>
> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> Cc: "Horia Geantă" <horia.geanta@nxp.com>
> Cc: Aymen Sghaier <aymen.sghaier@nxp.com>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: linux-crypto@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> Cc: linux-input@vger.kernel.org
> ---
>  .../devicetree/bindings/crypto/fsl-sec4.txt     | 17 +++++++++++++++++
>  arch/arm/boot/dts/imx7s.dtsi                    |  2 ++
>  2 files changed, 19 insertions(+)
> 

Acked-by: Rob Herring <robh@kernel.org>

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH 1/3] ARM: dts: imx7s: add snvs clock to pwrkey
  2020-01-30 20:45 [PATCH 1/3] ARM: dts: imx7s: add snvs clock to pwrkey André Draszik
                   ` (2 preceding siblings ...)
  2020-02-06 18:30 ` [PATCH 1/3] ARM: dts: imx7s: add snvs clock to pwrkey Rob Herring
@ 2020-02-07  7:36 ` Horia Geanta
  3 siblings, 0 replies; 13+ messages in thread
From: Horia Geanta @ 2020-02-07  7:36 UTC (permalink / raw)
  To: André Draszik, linux-kernel
  Cc: Anson Huang, Dmitry Torokhov, Aymen Sghaier, Herbert Xu,
	David S. Miller, Rob Herring, Mark Rutland, linux-crypto,
	devicetree, linux-input, Robin Gong, dl-linux-imx

On 1/30/2020 10:45 PM, André Draszik wrote:
> On i.MX7, the SNVS requires a clock. This is similar to the clock
> bound to the SNVS RTC node, but if the SNVS RTC driver isn't enabled,
> then SNVS doesn't work, and as such the pwrkey driver doesn't
> work (i.e. hangs the kernel, as the clock isn't enabled).
> 
This is true also for i.MX8M.
For this reason it would probably better splitting the
DT bindings update in a separate patch.

> Also see commit ec2a844ef7c1
> ("ARM: dts: imx7s: add snvs rtc clock")
> for a similar fix.
> 
> Signed-off-by: André Draszik <git@andred.net>
> Cc: Anson Huang <Anson.Huang@nxp.com>
> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> Cc: "Horia Geantă" <horia.geanta@nxp.com>
> Cc: Aymen Sghaier <aymen.sghaier@nxp.com>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: linux-crypto@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> Cc: linux-input@vger.kernel.org
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>

> ---
>  .../devicetree/bindings/crypto/fsl-sec4.txt     | 17 +++++++++++++++++
>  arch/arm/boot/dts/imx7s.dtsi                    |  2 ++
>  2 files changed, 19 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/crypto/fsl-sec4.txt b/Documentation/devicetree/bindings/crypto/fsl-sec4.txt
> index 2fe245ca816a..755c2838d658 100644
> --- a/Documentation/devicetree/bindings/crypto/fsl-sec4.txt
> +++ b/Documentation/devicetree/bindings/crypto/fsl-sec4.txt
> @@ -449,6 +449,19 @@ System ON/OFF key driver
>        Value type: <phandle>
>        Definition: this is phandle to the register map node.
>  
> +   - clocks
> +      Usage: optional, required if SNVS LP requires explicit
> +          enablement of clocks
> +      Value type: <prop_encoded-array>
> +      Definition:  a clock specifier describing the clock required for
> +          enabling and disabling SNVS LP RTC.
> +
> +   - clock-names
> +      Usage: optional, required if SNVS LP requires explicit
> +          enablement of clocks
> +      Value type: <string>
> +      Definition: clock name string should be "snvs-pwrkey".
> +
>  EXAMPLE:
>  	snvs-pwrkey@020cc000 {
>  		compatible = "fsl,sec-v4.0-pwrkey";
> @@ -456,6 +469,8 @@ EXAMPLE:
>  		interrupts = <0 4 0x4>
>  	        linux,keycode = <116>; /* KEY_POWER */
>  		wakeup-source;
> +		clocks = <&clks IMX7D_SNVS_CLK>;
> +		clock-names = "snvs-pwrkey";
>  	};
>  
>  =====================================================================
> @@ -547,6 +562,8 @@ FULL EXAMPLE
>  			interrupts = <0 4 0x4>;
>  			linux,keycode = <116>; /* KEY_POWER */
>  			wakeup-source;
> +			clocks = <&clks IMX7D_SNVS_CLK>;
> +			clock-names = "snvs-pwrkey";
>  		};
>  	};
>  
> diff --git a/arch/arm/boot/dts/imx7s.dtsi b/arch/arm/boot/dts/imx7s.dtsi
> index 1b812f4e7453..6240a6f58048 100644
> --- a/arch/arm/boot/dts/imx7s.dtsi
> +++ b/arch/arm/boot/dts/imx7s.dtsi
> @@ -614,6 +614,8 @@
>  					linux,keycode = <KEY_POWER>;
>  					wakeup-source;
>  					status = "disabled";
> +					clocks = <&clks IMX7D_SNVS_CLK>;
> +					clock-names = "snvs-pwrkey";
>  				};
>  			};
>  
> 

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH 2/3] Input: snvs_pwrkey - enable snvs clock as needed
  2020-01-30 20:45 ` [PATCH 2/3] Input: snvs_pwrkey - enable snvs clock as needed André Draszik
@ 2020-02-07  8:10   ` Horia Geanta
  2020-02-09 22:38     ` Dmitry Torokhov
  0 siblings, 1 reply; 13+ messages in thread
From: Horia Geanta @ 2020-02-07  8:10 UTC (permalink / raw)
  To: André Draszik, linux-kernel
  Cc: Anson Huang, Dmitry Torokhov, Aymen Sghaier, Herbert Xu,
	David S. Miller, Rob Herring, Mark Rutland, linux-crypto,
	devicetree, linux-input, Robin Gong, dl-linux-imx

On 1/30/2020 10:45 PM, André Draszik wrote:
> At the moment, enabling this driver without the SNVS RTC driver
> being active will hang the kernel as soon as the power button
> is pressed.
> 
> The reason is that in that case the SNVS isn't enabled, and
> any attempt to read the SNVS registers will simply hang forever.
> 
> Ensure the clock is enabled (during the interrupt handler) to
> make this driver work.
> 
> Also see commit 7f8993995410 ("drivers/rtc/rtc-snvs: add clock support")
> and commit edb190cb1734
> ("rtc: snvs: make sure clock is enabled for interrupt handle")
> for similar updates to the snvs rtc driver.
> 
> Signed-off-by: André Draszik <git@andred.net>
> Cc: Anson Huang <Anson.Huang@nxp.com>
> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> Cc: "Horia Geantă" <horia.geanta@nxp.com>
> Cc: Aymen Sghaier <aymen.sghaier@nxp.com>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: linux-crypto@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> Cc: linux-input@vger.kernel.org
> ---
>  drivers/input/keyboard/snvs_pwrkey.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/drivers/input/keyboard/snvs_pwrkey.c b/drivers/input/keyboard/snvs_pwrkey.c
> index 2f5e3ab5ed63..c29711d8735c 100644
> --- a/drivers/input/keyboard/snvs_pwrkey.c
> +++ b/drivers/input/keyboard/snvs_pwrkey.c
> @@ -16,6 +16,7 @@
>  #include <linux/of_address.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm_wakeirq.h>
> +#include <linux/clk.h>
>  #include <linux/mfd/syscon.h>
>  #include <linux/regmap.h>
>  
> @@ -38,6 +39,7 @@ struct pwrkey_drv_data {
>  	int wakeup;
>  	struct timer_list check_timer;
>  	struct input_dev *input;
> +	struct clk *clk;
>  	u8 minor_rev;
>  };
>  
> @@ -72,6 +74,9 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
>  	struct input_dev *input = pdata->input;
>  	u32 lp_status;
>  
> +	if (pdata->clk)
> +		clk_enable(pdata->clk);
> +
clk framework handles NULL pointers internally, the check is redundant.

>  	pm_wakeup_event(input->dev.parent, 0);
>  
>  	regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
> @@ -96,6 +101,9 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
>  	/* clear SPO status */
>  	regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
>  
> +	if (pdata->clk)
> +		clk_disable(pdata->clk);
> +
>  	return IRQ_HANDLED;
>  }
>  
> @@ -140,6 +148,25 @@ static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
>  	if (pdata->irq < 0)
>  		return -EINVAL;
>  
> +	pdata->clk = devm_clk_get(&pdev->dev, "snvs-pwrkey");
> +	if (IS_ERR(pdata->clk)) {
> +		pdata->clk = NULL;
Using devm_clk_get_optional() would simplify error handling.

> +	} else {
> +		error = clk_prepare_enable(pdata->clk);
> +		if (error) {
> +			dev_err(&pdev->dev,
> +				"Could not prepare or enable the snvs clock\n");
> +			return error;
> +		}
> +		error = devm_add_action_or_reset(&pdev->dev,
> +				(void(*)(void *))clk_disable_unprepare,
> +				pdata->clk);
> +		if (error) {
> +			dev_err(&pdev->dev, "failed to add reset action on 'snvs-pwrkey'");
> +			return error;
> +		}
> +	}
> +
>  	regmap_read(pdata->snvs, SNVS_HPVIDR1_REG, &vid);
>  	pdata->minor_rev = vid & 0xff;
>  
> 

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH 2/3] Input: snvs_pwrkey - enable snvs clock as needed
  2020-02-07  8:10   ` Horia Geanta
@ 2020-02-09 22:38     ` Dmitry Torokhov
  2020-02-10  2:03       ` Robin Gong
  0 siblings, 1 reply; 13+ messages in thread
From: Dmitry Torokhov @ 2020-02-09 22:38 UTC (permalink / raw)
  To: Horia Geanta
  Cc: André Draszik, linux-kernel, Anson Huang, Aymen Sghaier,
	Herbert Xu, David S. Miller, Rob Herring, Mark Rutland,
	linux-crypto, devicetree, linux-input, Robin Gong, dl-linux-imx

On Fri, Feb 07, 2020 at 08:10:22AM +0000, Horia Geanta wrote:
> On 1/30/2020 10:45 PM, André Draszik wrote:
> > At the moment, enabling this driver without the SNVS RTC driver
> > being active will hang the kernel as soon as the power button
> > is pressed.
> > 
> > The reason is that in that case the SNVS isn't enabled, and
> > any attempt to read the SNVS registers will simply hang forever.
> > 
> > Ensure the clock is enabled (during the interrupt handler) to
> > make this driver work.
> > 
> > Also see commit 7f8993995410 ("drivers/rtc/rtc-snvs: add clock support")
> > and commit edb190cb1734
> > ("rtc: snvs: make sure clock is enabled for interrupt handle")
> > for similar updates to the snvs rtc driver.
> > 
> > Signed-off-by: André Draszik <git@andred.net>
> > Cc: Anson Huang <Anson.Huang@nxp.com>
> > Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> > Cc: "Horia Geantă" <horia.geanta@nxp.com>
> > Cc: Aymen Sghaier <aymen.sghaier@nxp.com>
> > Cc: Herbert Xu <herbert@gondor.apana.org.au>
> > Cc: "David S. Miller" <davem@davemloft.net>
> > Cc: Rob Herring <robh+dt@kernel.org>
> > Cc: Mark Rutland <mark.rutland@arm.com>
> > Cc: linux-crypto@vger.kernel.org
> > Cc: devicetree@vger.kernel.org
> > Cc: linux-input@vger.kernel.org
> > ---
> >  drivers/input/keyboard/snvs_pwrkey.c | 27 +++++++++++++++++++++++++++
> >  1 file changed, 27 insertions(+)
> > 
> > diff --git a/drivers/input/keyboard/snvs_pwrkey.c b/drivers/input/keyboard/snvs_pwrkey.c
> > index 2f5e3ab5ed63..c29711d8735c 100644
> > --- a/drivers/input/keyboard/snvs_pwrkey.c
> > +++ b/drivers/input/keyboard/snvs_pwrkey.c
> > @@ -16,6 +16,7 @@
> >  #include <linux/of_address.h>
> >  #include <linux/platform_device.h>
> >  #include <linux/pm_wakeirq.h>
> > +#include <linux/clk.h>
> >  #include <linux/mfd/syscon.h>
> >  #include <linux/regmap.h>
> >  
> > @@ -38,6 +39,7 @@ struct pwrkey_drv_data {
> >  	int wakeup;
> >  	struct timer_list check_timer;
> >  	struct input_dev *input;
> > +	struct clk *clk;
> >  	u8 minor_rev;
> >  };
> >  
> > @@ -72,6 +74,9 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
> >  	struct input_dev *input = pdata->input;
> >  	u32 lp_status;
> >  
> > +	if (pdata->clk)
> > +		clk_enable(pdata->clk);
> > +
> clk framework handles NULL pointers internally, the check is redundant.
> 
> >  	pm_wakeup_event(input->dev.parent, 0);
> >  
> >  	regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
> > @@ -96,6 +101,9 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
> >  	/* clear SPO status */
> >  	regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
> >  
> > +	if (pdata->clk)
> > +		clk_disable(pdata->clk);
> > +
> >  	return IRQ_HANDLED;
> >  }
> >  
> > @@ -140,6 +148,25 @@ static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
> >  	if (pdata->irq < 0)
> >  		return -EINVAL;
> >  
> > +	pdata->clk = devm_clk_get(&pdev->dev, "snvs-pwrkey");
> > +	if (IS_ERR(pdata->clk)) {
> > +		pdata->clk = NULL;
> Using devm_clk_get_optional() would simplify error handling.

It sounds to me that this clock is not at all optional and the driver
currently "works" only by accident and therefore optional is not
suitable here.

> 
> > +	} else {
> > +		error = clk_prepare_enable(pdata->clk);

So if you enable clock here and do not disable it, why do you need to
enable it again in interrupt?

Thanks.

-- 
Dmitry

^ permalink raw reply	[flat|nested] 13+ messages in thread

* RE: [PATCH 2/3] Input: snvs_pwrkey - enable snvs clock as needed
  2020-02-09 22:38     ` Dmitry Torokhov
@ 2020-02-10  2:03       ` Robin Gong
  2020-02-10  6:33         ` Horia Geanta
  0 siblings, 1 reply; 13+ messages in thread
From: Robin Gong @ 2020-02-10  2:03 UTC (permalink / raw)
  To: Dmitry Torokhov, Horia Geanta
  Cc: André Draszik, linux-kernel, Anson Huang, Aymen Sghaier,
	Herbert Xu, David S. Miller, Rob Herring, Mark Rutland,
	linux-crypto, devicetree, linux-input, dl-linux-imx


On 2020/02/10 Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: 
> On Fri, Feb 07, 2020 at 08:10:22AM +0000, Horia Geanta wrote:
> > On 1/30/2020 10:45 PM, André Draszik wrote:
> > > At the moment, enabling this driver without the SNVS RTC driver
> > > being active will hang the kernel as soon as the power button is
> > > pressed.
> > >
> > > The reason is that in that case the SNVS isn't enabled, and any
> > > attempt to read the SNVS registers will simply hang forever.
> > >
> > > Ensure the clock is enabled (during the interrupt handler) to make
> > > this driver work.
Besides, need to add clock enabled in imx_imx_snvs_check_for_events
where snvs register touched.
> > >
> > > Also see commit 7f8993995410 ("drivers/rtc/rtc-snvs: add clock
> > > support") and commit edb190cb1734
> > > ("rtc: snvs: make sure clock is enabled for interrupt handle") for
> > > similar updates to the snvs rtc driver.
> > >
> > > Signed-off-by: André Draszik <git@andred.net>
> > > Cc: Anson Huang <Anson.Huang@nxp.com>
> > > Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> > > Cc: "Horia Geantă" <horia.geanta@nxp.com>
> > > Cc: Aymen Sghaier <aymen.sghaier@nxp.com>
> > > Cc: Herbert Xu <herbert@gondor.apana.org.au>
> > > Cc: "David S. Miller" <davem@davemloft.net>
> > > Cc: Rob Herring <robh+dt@kernel.org>
> > > Cc: Mark Rutland <mark.rutland@arm.com>
> > > Cc: linux-crypto@vger.kernel.org
> > > Cc: devicetree@vger.kernel.org
> > > Cc: linux-input@vger.kernel.org
> > > ---
> > >  drivers/input/keyboard/snvs_pwrkey.c | 27
> > > +++++++++++++++++++++++++++
> > >  1 file changed, 27 insertions(+)
> > >
> > > diff --git a/drivers/input/keyboard/snvs_pwrkey.c
> > > b/drivers/input/keyboard/snvs_pwrkey.c
> > > index 2f5e3ab5ed63..c29711d8735c 100644
> > > --- a/drivers/input/keyboard/snvs_pwrkey.c
> > > +++ b/drivers/input/keyboard/snvs_pwrkey.c
> > > @@ -16,6 +16,7 @@
> > >  #include <linux/of_address.h>
> > >  #include <linux/platform_device.h>
> > >  #include <linux/pm_wakeirq.h>
> > > +#include <linux/clk.h>
> > >  #include <linux/mfd/syscon.h>
> > >  #include <linux/regmap.h>
> > >
> > > @@ -38,6 +39,7 @@ struct pwrkey_drv_data {
> > >  	int wakeup;
> > >  	struct timer_list check_timer;
> > >  	struct input_dev *input;
> > > +	struct clk *clk;
> > >  	u8 minor_rev;
> > >  };
> > >
> > > @@ -72,6 +74,9 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq,
> void *dev_id)
> > >  	struct input_dev *input = pdata->input;
> > >  	u32 lp_status;
> > >
> > > +	if (pdata->clk)
> > > +		clk_enable(pdata->clk);
> > > +
> > clk framework handles NULL pointers internally, the check is redundant.
> >
> > >  	pm_wakeup_event(input->dev.parent, 0);
> > >
> > >  	regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status); @@ -96,6
> > > +101,9 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void
> *dev_id)
> > >  	/* clear SPO status */
> > >  	regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
> > >
> > > +	if (pdata->clk)
> > > +		clk_disable(pdata->clk);
> > > +
> > >  	return IRQ_HANDLED;
> > >  }
> > >
> > > @@ -140,6 +148,25 @@ static int imx_snvs_pwrkey_probe(struct
> platform_device *pdev)
> > >  	if (pdata->irq < 0)
> > >  		return -EINVAL;
> > >
> > > +	pdata->clk = devm_clk_get(&pdev->dev, "snvs-pwrkey");
> > > +	if (IS_ERR(pdata->clk)) {
> > > +		pdata->clk = NULL;
> > Using devm_clk_get_optional() would simplify error handling.
> 
> It sounds to me that this clock is not at all optional and the driver currently
> "works" only by accident and therefore optional is not suitable here.
Yes, then we need to add all snvs clk in dts for on legacy i.MX chips in this patchset
to avoid any potential function broken.
> 
> >
> > > +	} else {
> > > +		error = clk_prepare_enable(pdata->clk);
> 
> So if you enable clock here and do not disable it, why do you need to enable it
> again in interrupt?
> 
> Thanks.
> 
> --
> Dmitry

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH 2/3] Input: snvs_pwrkey - enable snvs clock as needed
  2020-02-10  2:03       ` Robin Gong
@ 2020-02-10  6:33         ` Horia Geanta
  2020-02-10 17:55           ` Dmitry Torokhov
  0 siblings, 1 reply; 13+ messages in thread
From: Horia Geanta @ 2020-02-10  6:33 UTC (permalink / raw)
  To: Robin Gong, Dmitry Torokhov
  Cc: André Draszik, linux-kernel, Anson Huang, Aymen Sghaier,
	Herbert Xu, David S. Miller, Rob Herring, Mark Rutland,
	linux-crypto, devicetree, linux-input, dl-linux-imx

On 2/10/2020 4:03 AM, Robin Gong wrote:
> On 2020/02/10 Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: 
>> On Fri, Feb 07, 2020 at 08:10:22AM +0000, Horia Geanta wrote:
>>> On 1/30/2020 10:45 PM, André Draszik wrote:
>>>> @@ -140,6 +148,25 @@ static int imx_snvs_pwrkey_probe(struct
>> platform_device *pdev)
>>>>  	if (pdata->irq < 0)
>>>>  		return -EINVAL;
>>>>
>>>> +	pdata->clk = devm_clk_get(&pdev->dev, "snvs-pwrkey");
>>>> +	if (IS_ERR(pdata->clk)) {
>>>> +		pdata->clk = NULL;
>>> Using devm_clk_get_optional() would simplify error handling.
>>
>> It sounds to me that this clock is not at all optional and the driver currently
>> "works" only by accident and therefore optional is not suitable here.
> Yes, then we need to add all snvs clk in dts for on legacy i.MX chips in this patchset
> to avoid any potential function broken.
In that case the DT binding should be updated too,
to make the clock mandatory.
But before doing this all i.MX SoCs should be checked.

Thanks,
Horia

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH 2/3] Input: snvs_pwrkey - enable snvs clock as needed
  2020-02-10  6:33         ` Horia Geanta
@ 2020-02-10 17:55           ` Dmitry Torokhov
  2020-02-11  1:54             ` Robin Gong
  0 siblings, 1 reply; 13+ messages in thread
From: Dmitry Torokhov @ 2020-02-10 17:55 UTC (permalink / raw)
  To: Horia Geanta
  Cc: Robin Gong, André Draszik, linux-kernel, Anson Huang,
	Aymen Sghaier, Herbert Xu, David S. Miller, Rob Herring,
	Mark Rutland, linux-crypto, devicetree, linux-input,
	dl-linux-imx

On Mon, Feb 10, 2020 at 06:33:30AM +0000, Horia Geanta wrote:
> On 2/10/2020 4:03 AM, Robin Gong wrote:
> > On 2020/02/10 Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: 
> >> On Fri, Feb 07, 2020 at 08:10:22AM +0000, Horia Geanta wrote:
> >>> On 1/30/2020 10:45 PM, André Draszik wrote:
> >>>> @@ -140,6 +148,25 @@ static int imx_snvs_pwrkey_probe(struct
> >> platform_device *pdev)
> >>>>  	if (pdata->irq < 0)
> >>>>  		return -EINVAL;
> >>>>
> >>>> +	pdata->clk = devm_clk_get(&pdev->dev, "snvs-pwrkey");
> >>>> +	if (IS_ERR(pdata->clk)) {
> >>>> +		pdata->clk = NULL;
> >>> Using devm_clk_get_optional() would simplify error handling.
> >>
> >> It sounds to me that this clock is not at all optional and the driver currently
> >> "works" only by accident and therefore optional is not suitable here.
> > Yes, then we need to add all snvs clk in dts for on legacy i.MX chips in this patchset
> > to avoid any potential function broken.

How many are there? I am not too terribly opposed of having the driver
handle missing clk if there are very many legacy DTSes out there. But
then we need to handle it properly (i.e. current iteration does not
handle referral properly for example).

> In that case the DT binding should be updated too,
> to make the clock mandatory.

I think this should be done in either case, as as far I understand the
part can not function without the clock and it worked purely by chance
on some systems as something else was turning the clock on.

Thanks.

-- 
Dmitry

^ permalink raw reply	[flat|nested] 13+ messages in thread

* RE: [PATCH 2/3] Input: snvs_pwrkey - enable snvs clock as needed
  2020-02-10 17:55           ` Dmitry Torokhov
@ 2020-02-11  1:54             ` Robin Gong
  2020-02-11  9:13               ` André Draszik
  0 siblings, 1 reply; 13+ messages in thread
From: Robin Gong @ 2020-02-11  1:54 UTC (permalink / raw)
  To: Dmitry Torokhov, Horia Geanta
  Cc: André Draszik, linux-kernel, Anson Huang, Aymen Sghaier,
	Herbert Xu, David S. Miller, Rob Herring, Mark Rutland,
	linux-crypto, devicetree, linux-input, dl-linux-imx

On 2020/02/11 Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: 
> On Mon, Feb 10, 2020 at 06:33:30AM +0000, Horia Geanta wrote:
> > On 2/10/2020 4:03 AM, Robin Gong wrote:
> > > On 2020/02/10 Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:
> > >> On Fri, Feb 07, 2020 at 08:10:22AM +0000, Horia Geanta wrote:
> > >>> On 1/30/2020 10:45 PM, André Draszik wrote:
> > >>>> @@ -140,6 +148,25 @@ static int imx_snvs_pwrkey_probe(struct
> > >> platform_device *pdev)
> > >>>>  	if (pdata->irq < 0)
> > >>>>  		return -EINVAL;
> > >>>>
> > >>>> +	pdata->clk = devm_clk_get(&pdev->dev, "snvs-pwrkey");
> > >>>> +	if (IS_ERR(pdata->clk)) {
> > >>>> +		pdata->clk = NULL;
> > >>> Using devm_clk_get_optional() would simplify error handling.
> > >>
> > >> It sounds to me that this clock is not at all optional and the
> > >> driver currently "works" only by accident and therefore optional is not
> suitable here.
> > > Yes, then we need to add all snvs clk in dts for on legacy i.MX
> > > chips in this patchset to avoid any potential function broken.
> 
> How many are there? I am not too terribly opposed of having the driver handle
> missing clk if there are very many legacy DTSes out there. But then we need to
> handle it properly (i.e. current iteration does not handle referral properly for
> example).
There are four dtsi which have clock support in snvs-rtc  including i.mx7s/i.mx8mq/8mm/8mn. So for this patch set, it's better update
i.mx8mX dtsi except i.mx7s.
> 
> > In that case the DT binding should be updated too, to make the clock
> > mandatory.
> 
> I think this should be done in either case, as as far I understand the part can not
> function without the clock and it worked purely by chance on some systems as
> something else was turning the clock on.
Yes, for all chips snvs clk management added, snvs clock also has to been add
in snvs_pwrkey dts, but for others legacy chips like i.mx6X which have no snvs
clk management, snvs clock is always on, so no need such clk in snvs_pwrkey
dts either, optional is better.
> 
> Thanks.
> 
> --
> Dmitry

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH 2/3] Input: snvs_pwrkey - enable snvs clock as needed
  2020-02-11  1:54             ` Robin Gong
@ 2020-02-11  9:13               ` André Draszik
  2020-02-12  0:58                 ` Robin Gong
  0 siblings, 1 reply; 13+ messages in thread
From: André Draszik @ 2020-02-11  9:13 UTC (permalink / raw)
  To: Robin Gong, Dmitry Torokhov, Horia Geanta
  Cc: linux-kernel, Anson Huang, Aymen Sghaier, Herbert Xu,
	David S. Miller, Rob Herring, Mark Rutland, linux-crypto,
	devicetree, linux-input, dl-linux-imx

Hi,

On Tue, 2020-02-11 at 01:54 +0000, Robin Gong wrote:
> On 2020/02/11 Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: 
> > On Mon, Feb 10, 2020 at 06:33:30AM +0000, Horia Geanta wrote:
> > > On 2/10/2020 4:03 AM, Robin Gong wrote:
> > > > On 2020/02/10 Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:
> > > > > On Fri, Feb 07, 2020 at 08:10:22AM +0000, Horia Geanta wrote:
> > > > > > On 1/30/2020 10:45 PM, André Draszik wrote:
> > > > > > > @@ -140,6 +148,25 @@ static int imx_snvs_pwrkey_probe(struct
> > > > > platform_device *pdev)
> > > > > > >  	if (pdata->irq < 0)
> > > > > > >  		return -EINVAL;
> > > > > > > 
> > > > > > > +	pdata->clk = devm_clk_get(&pdev->dev, "snvs-pwrkey");
> > > > > > > +	if (IS_ERR(pdata->clk)) {
> > > > > > > +		pdata->clk = NULL;
> > > > > > Using devm_clk_get_optional() would simplify error handling.
> > > > > 
> > > > > It sounds to me that this clock is not at all optional and the
> > > > > driver currently "works" only by accident and therefore optional is not
> > suitable here.
> > > > Yes, then we need to add all snvs clk in dts for on legacy i.MX
> > > > chips in this patchset to avoid any potential function broken.
> > 
> > How many are there? I am not too terribly opposed of having the driver handle
> > missing clk if there are very many legacy DTSes out there. But then we need to
> > handle it properly (i.e. current iteration does not handle referral properly for
> > example).
> There are four dtsi which have clock support in snvs-rtc  including i.mx7s/i.mx8mq/8mm/8mn. So for this patch set,
> it's better update
> i.mx8mX dtsi except i.mx7s.
> > > In that case the DT binding should be updated too, to make the clock
> > > mandatory.
> > 
> > I think this should be done in either case, as as far I understand the part can not
> > function without the clock and it worked purely by chance on some systems as
> > something else was turning the clock on.
> Yes, for all chips snvs clk management added, snvs clock also has to been add
> in snvs_pwrkey dts, but for others legacy chips like i.mx6X which have no snvs
> clk management, snvs clock is always on, so no need such clk in snvs_pwrkey
> dts either, optional is better.
> > Thanks.

It seems to me though that the clock should really be moved into the (parent) SNVS
node itself, rather than duplicating
the clock in the the power key node and in
the RTC node. Is that possible? (I don't know)...

To summarise, I'll post an updated patchset within the next couple days so to:

* keep the clock optional (for i.MX6 platforms)
* convert to devm_clk_get_optional()
* only enable the clock in interrupt handler and imx_imx_snvs_check_for_events()
  but not during driver loading
* update all four DTSIs: imx8mm.dtsi imx8mn.dtsi imx8mq.dtsi imx7s.dtsi
  Note that I'll only be able to test onn the i.MX7


Cheers,
Andre'



^ permalink raw reply	[flat|nested] 13+ messages in thread

* RE: [PATCH 2/3] Input: snvs_pwrkey - enable snvs clock as needed
  2020-02-11  9:13               ` André Draszik
@ 2020-02-12  0:58                 ` Robin Gong
  0 siblings, 0 replies; 13+ messages in thread
From: Robin Gong @ 2020-02-12  0:58 UTC (permalink / raw)
  To: André Draszik, Dmitry Torokhov, Horia Geanta
  Cc: linux-kernel, Anson Huang, Aymen Sghaier, Herbert Xu,
	David S. Miller, Rob Herring, Mark Rutland, linux-crypto,
	devicetree, linux-input, dl-linux-imx

On 2020/02/11 André Draszik <git@andred.net> wrote:
> Hi,
> 
> On Tue, 2020-02-11 at 01:54 +0000, Robin Gong wrote:
> > On 2020/02/11 Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:
> > > On Mon, Feb 10, 2020 at 06:33:30AM +0000, Horia Geanta wrote:
> > > > On 2/10/2020 4:03 AM, Robin Gong wrote:
> > > > > On 2020/02/10 Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:
> > > > > > On Fri, Feb 07, 2020 at 08:10:22AM +0000, Horia Geanta wrote:
> > > > > > > On 1/30/2020 10:45 PM, André Draszik wrote:
> > > > > > > > @@ -140,6 +148,25 @@ static int
> > > > > > > > imx_snvs_pwrkey_probe(struct
> > > > > > platform_device *pdev)
> > > > > > > >  	if (pdata->irq < 0)
> > > > > > > >  		return -EINVAL;
> > > > > > > >
> > > > > > > > +	pdata->clk = devm_clk_get(&pdev->dev, "snvs-pwrkey");
> > > > > > > > +	if (IS_ERR(pdata->clk)) {
> > > > > > > > +		pdata->clk = NULL;
> > > > > > > Using devm_clk_get_optional() would simplify error handling.
> > > > > >
> > > > > > It sounds to me that this clock is not at all optional and the
> > > > > > driver currently "works" only by accident and therefore
> > > > > > optional is not
> > > suitable here.
> > > > > Yes, then we need to add all snvs clk in dts for on legacy i.MX
> > > > > chips in this patchset to avoid any potential function broken.
> > >
> > > How many are there? I am not too terribly opposed of having the
> > > driver handle missing clk if there are very many legacy DTSes out
> > > there. But then we need to handle it properly (i.e. current
> > > iteration does not handle referral properly for example).
> > There are four dtsi which have clock support in snvs-rtc  including
> > i.mx7s/i.mx8mq/8mm/8mn. So for this patch set, it's better update
> > i.mx8mX dtsi except i.mx7s.
> > > > In that case the DT binding should be updated too, to make the
> > > > clock mandatory.
> > >
> > > I think this should be done in either case, as as far I understand
> > > the part can not function without the clock and it worked purely by
> > > chance on some systems as something else was turning the clock on.
> > Yes, for all chips snvs clk management added, snvs clock also has to
> > been add in snvs_pwrkey dts, but for others legacy chips like i.mx6X
> > which have no snvs clk management, snvs clock is always on, so no need
> > such clk in snvs_pwrkey dts either, optional is better.
> > > Thanks.
> 
> It seems to me though that the clock should really be moved into the (parent)
> SNVS node itself, rather than duplicating the clock in the the power key node
> and in the RTC node. Is that possible? (I don't know)...
That's possible but much code changes need to be added into snvs-rtc/snvs_pwrkey
driver. Independent patch is better.
> 
> To summarise, I'll post an updated patchset within the next couple days so to:
> 
> * keep the clock optional (for i.MX6 platforms)
> * convert to devm_clk_get_optional()
> * only enable the clock in interrupt handler and
> imx_imx_snvs_check_for_events()
>   but not during driver loading
> * update all four DTSIs: imx8mm.dtsi imx8mn.dtsi imx8mq.dtsi imx7s.dtsi
>   Note that I'll only be able to test onn the i.MX7
Correct.
> 
> 
> Cheers,
> Andre'
> 


^ permalink raw reply	[flat|nested] 13+ messages in thread

end of thread, back to index

Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-01-30 20:45 [PATCH 1/3] ARM: dts: imx7s: add snvs clock to pwrkey André Draszik
2020-01-30 20:45 ` [PATCH 2/3] Input: snvs_pwrkey - enable snvs clock as needed André Draszik
2020-02-07  8:10   ` Horia Geanta
2020-02-09 22:38     ` Dmitry Torokhov
2020-02-10  2:03       ` Robin Gong
2020-02-10  6:33         ` Horia Geanta
2020-02-10 17:55           ` Dmitry Torokhov
2020-02-11  1:54             ` Robin Gong
2020-02-11  9:13               ` André Draszik
2020-02-12  0:58                 ` Robin Gong
2020-01-30 20:45 ` [PATCH 3/3] Input: snvs_pwrkey - only IRQ_HANDLED for our own events André Draszik
2020-02-06 18:30 ` [PATCH 1/3] ARM: dts: imx7s: add snvs clock to pwrkey Rob Herring
2020-02-07  7:36 ` Horia Geanta

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