[PATCH 0/4] pinctrl: pinctrl-zynqmp: Add tri-state configuration support

[PATCH 0/4] pinctrl: pinctrl-zynqmp: Add tri-state configuration support

[Sai Krishna Potthuri]

This series update the Xilinx firmware, ZynqMP dt-binding and ZynqMP
pinctrl driver to handle 'output-enable' and 'bias-high-impedance'
configurations. As part of these configurations, ZynqMP pinctrl driver
takes care of pin tri-state setting.
Also fix the kernel doc warning in ZynqMP pinctrl driver.

Note: Resending the series as i see this series didn't went out due
to some issue with my mail client. Please ignore if this series is 
already received.

Sai Krishna Potthuri (4):
  firmware: xilinx: Add configuration values for tri-state
  dt-bindings: pinctrl-zynqmp: Add output-enable configuration
  pinctrl: pinctrl-zynqmp: Add support for output-enable and
    bias-high-impedance
  pinctrl: pinctrl-zynqmp: Fix kernel-doc warning

 .../bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml         |  4 ++++
 drivers/pinctrl/pinctrl-zynqmp.c                      | 11 +++++++++++
 include/linux/firmware/xlnx-zynqmp.h                  |  5 +++++
 3 files changed, 20 insertions(+)

-- 
2.17.1


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[PATCH 1/4] firmware: xilinx: Add configuration values for tri-state

[Sai Krishna Potthuri]

Add configuration values(enable/disable) for tri-state parameter.

Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
---
 include/linux/firmware/xlnx-zynqmp.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/firmware/xlnx-zynqmp.h b/include/linux/firmware/xlnx-zynqmp.h
index 14f00a7672d1..7c4d2297cac1 100644
--- a/include/linux/firmware/xlnx-zynqmp.h
+++ b/include/linux/firmware/xlnx-zynqmp.h
@@ -363,6 +363,11 @@ enum pm_pinctrl_drive_strength {
 	PM_PINCTRL_DRIVE_STRENGTH_12MA = 3,
 };
 
+enum pm_pinctrl_tri_state {
+	PM_PINCTRL_TRI_STATE_DISABLE = 0,
+	PM_PINCTRL_TRI_STATE_ENABLE = 1,
+};
+
 enum zynqmp_pm_shutdown_type {
 	ZYNQMP_PM_SHUTDOWN_TYPE_SHUTDOWN = 0,
 	ZYNQMP_PM_SHUTDOWN_TYPE_RESET = 1,
-- 
2.17.1


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[PATCH 2/4] dt-bindings: pinctrl-zynqmp: Add output-enable configuration

[Sai Krishna Potthuri]

Add 'output-enable' configuration parameter to the properties list.

Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
---
 .../devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml      | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml
index 2722dc7bb03d..1e2b9b627b12 100644
--- a/Documentation/devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml
+++ b/Documentation/devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml
@@ -274,6 +274,10 @@ patternProperties:
           slew-rate:
             enum: [0, 1]
 
+          output-enable:
+            description:
+              This will internally disable the tri-state for MIO pins.
+
           drive-strength:
             description:
               Selects the drive strength for MIO pins, in mA.
-- 
2.17.1


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[PATCH 3/4] pinctrl: pinctrl-zynqmp: Add support for output-enable and bias-high-impedance

[Sai Krishna Potthuri]

Add support to handle 'output-enable' and 'bias-high-impedance'
configurations. As part of the output-enable configuration, ZynqMP pinctrl
driver takes care of removing the pins from tri-state.

Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
---
 drivers/pinctrl/pinctrl-zynqmp.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/pinctrl/pinctrl-zynqmp.c b/drivers/pinctrl/pinctrl-zynqmp.c
index e14012209992..b25e9e76fbf8 100644
--- a/drivers/pinctrl/pinctrl-zynqmp.c
+++ b/drivers/pinctrl/pinctrl-zynqmp.c
@@ -410,6 +410,10 @@ static int zynqmp_pinconf_cfg_set(struct pinctrl_dev *pctldev,
 
 			break;
 		case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
+			param = PM_PINCTRL_CONFIG_TRI_STATE;
+			arg = PM_PINCTRL_TRI_STATE_ENABLE;
+			ret = zynqmp_pm_pinctrl_set_config(pin, param, arg);
+			break;
 		case PIN_CONFIG_MODE_LOW_POWER:
 			/*
 			 * These cases are mentioned in dts but configurable
@@ -418,6 +422,11 @@ static int zynqmp_pinconf_cfg_set(struct pinctrl_dev *pctldev,
 			 */
 			ret = 0;
 			break;
+		case PIN_CONFIG_OUTPUT_ENABLE:
+			param = PM_PINCTRL_CONFIG_TRI_STATE;
+			arg = PM_PINCTRL_TRI_STATE_DISABLE;
+			ret = zynqmp_pm_pinctrl_set_config(pin, param, arg);
+			break;
 		default:
 			dev_warn(pctldev->dev,
 				 "unsupported configuration parameter '%u'\n",
-- 
2.17.1


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[PATCH 4/4] pinctrl: pinctrl-zynqmp: Fix kernel-doc warning

[Sai Krishna Potthuri]

Fix the below kernel-doc warning by adding the description for return
value.
"warning: No description found for return value of
'zynqmp_pmux_get_function_groups'".

Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
---
 drivers/pinctrl/pinctrl-zynqmp.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pinctrl/pinctrl-zynqmp.c b/drivers/pinctrl/pinctrl-zynqmp.c
index b25e9e76fbf8..7d2fbf8a02cd 100644
--- a/drivers/pinctrl/pinctrl-zynqmp.c
+++ b/drivers/pinctrl/pinctrl-zynqmp.c
@@ -163,6 +163,8 @@ static const char *zynqmp_pmux_get_function_name(struct pinctrl_dev *pctldev,
  * @num_groups:	Number of function groups.
  *
  * Get function's group count and group names.
+ *
+ * Return: 0
  */
 static int zynqmp_pmux_get_function_groups(struct pinctrl_dev *pctldev,
 					   unsigned int selector,
-- 
2.17.1


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Re: [PATCH 2/4] dt-bindings: pinctrl-zynqmp: Add output-enable configuration

[Rob Herring]

On Fri, 17 Jun 2022 16:16:57 +0530, Sai Krishna Potthuri wrote:
> Add 'output-enable' configuration parameter to the properties list.
> 
> Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
> ---
>  .../devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml      | 4 ++++
>  1 file changed, 4 insertions(+)
> 

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

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Re: [PATCH 0/4] pinctrl: pinctrl-zynqmp: Add tri-state configuration support

[Linus Walleij]

On Fri, Jun 17, 2022 at 12:47 PM Sai Krishna Potthuri
<lakshmi.sai.krishna.potthuri@xilinx.com> wrote:

> This series update the Xilinx firmware, ZynqMP dt-binding and ZynqMP
> pinctrl driver to handle 'output-enable' and 'bias-high-impedance'
> configurations. As part of these configurations, ZynqMP pinctrl driver
> takes care of pin tri-state setting.
> Also fix the kernel doc warning in ZynqMP pinctrl driver.
>
> Note: Resending the series as i see this series didn't went out due
> to some issue with my mail client. Please ignore if this series is
> already received.
>
> Sai Krishna Potthuri (4):
>   firmware: xilinx: Add configuration values for tri-state
>   dt-bindings: pinctrl-zynqmp: Add output-enable configuration
>   pinctrl: pinctrl-zynqmp: Add support for output-enable and
>     bias-high-impedance
>   pinctrl: pinctrl-zynqmp: Fix kernel-doc warning

Excellent work, patches applied!

Yours,
Linus Walleij

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Re: [PATCH 0/4] pinctrl: pinctrl-zynqmp: Add tri-state configuration support

[Laurent Pinchart]

Hi Sai,

On Fri, Jun 17, 2022 at 04:16:55PM +0530, Sai Krishna Potthuri wrote:
> This series update the Xilinx firmware, ZynqMP dt-binding and ZynqMP
> pinctrl driver to handle 'output-enable' and 'bias-high-impedance'
> configurations. As part of these configurations, ZynqMP pinctrl driver
> takes care of pin tri-state setting.
> Also fix the kernel doc warning in ZynqMP pinctrl driver.

I'm afraid this causes a regression :-( With this series applied, boot
breaks with the following message being printed to the serial console:

Received exception
MSR: 0x200, EAR: 0xFF180198, EDR: 0x0, ESR: 0x64

I've traced that to the probe of the UART, when it calls into the
firmware to set pin MIO18 to high impedance. According to v1.7 of the
ZynqMP registers reference (UG1087), there is no register at address
0xFF180198.

I am using the VCU TRD 2021.1 for testing. Does this series require a
firmware update ? If so backward compatibility needs to be preserved.
It's very late in the v6.0-rc cycle for a fix, a revert may be best at
this point, to give us time to fix the issue properly.

> Note: Resending the series as i see this series didn't went out due
> to some issue with my mail client. Please ignore if this series is 
> already received.
> 
> Sai Krishna Potthuri (4):
>   firmware: xilinx: Add configuration values for tri-state
>   dt-bindings: pinctrl-zynqmp: Add output-enable configuration
>   pinctrl: pinctrl-zynqmp: Add support for output-enable and
>     bias-high-impedance
>   pinctrl: pinctrl-zynqmp: Fix kernel-doc warning
> 
>  .../bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml         |  4 ++++
>  drivers/pinctrl/pinctrl-zynqmp.c                      | 11 +++++++++++
>  include/linux/firmware/xlnx-zynqmp.h                  |  5 +++++
>  3 files changed, 20 insertions(+)

-- 
Regards,

Laurent Pinchart

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Re: [PATCH 0/4] pinctrl: pinctrl-zynqmp: Add tri-state configuration support

[Laurent Pinchart]

On Wed, Sep 28, 2022 at 06:58:10PM +0300, Laurent Pinchart wrote:
> Hi Sai,
> 
> On Fri, Jun 17, 2022 at 04:16:55PM +0530, Sai Krishna Potthuri wrote:
> > This series update the Xilinx firmware, ZynqMP dt-binding and ZynqMP
> > pinctrl driver to handle 'output-enable' and 'bias-high-impedance'
> > configurations. As part of these configurations, ZynqMP pinctrl driver
> > takes care of pin tri-state setting.
> > Also fix the kernel doc warning in ZynqMP pinctrl driver.
> 
> I'm afraid this causes a regression :-( With this series applied, boot
> breaks with the following message being printed to the serial console:
> 
> Received exception
> MSR: 0x200, EAR: 0xFF180198, EDR: 0x0, ESR: 0x64
> 
> I've traced that to the probe of the UART, when it calls into the
> firmware to set pin MIO18 to high impedance. According to v1.7 of the
> ZynqMP registers reference (UG1087), there is no register at address
> 0xFF180198.
> 
> I am using the VCU TRD 2021.1 for testing. Does this series require a
> firmware update ? If so backward compatibility needs to be preserved.
> It's very late in the v6.0-rc cycle for a fix, a revert may be best at
> this point, to give us time to fix the issue properly.

I've now tested the VCU TRD 2022.1 (which AFAIK is the latest available
version), and the problem doesn't occue then. It thus seems this depends
on a firmware update, which is impractical at best for all old designs
:-(

> > Note: Resending the series as i see this series didn't went out due
> > to some issue with my mail client. Please ignore if this series is 
> > already received.
> > 
> > Sai Krishna Potthuri (4):
> >   firmware: xilinx: Add configuration values for tri-state
> >   dt-bindings: pinctrl-zynqmp: Add output-enable configuration
> >   pinctrl: pinctrl-zynqmp: Add support for output-enable and
> >     bias-high-impedance
> >   pinctrl: pinctrl-zynqmp: Fix kernel-doc warning
> > 
> >  .../bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml         |  4 ++++
> >  drivers/pinctrl/pinctrl-zynqmp.c                      | 11 +++++++++++
> >  include/linux/firmware/xlnx-zynqmp.h                  |  5 +++++
> >  3 files changed, 20 insertions(+)

-- 
Regards,

Laurent Pinchart

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Re: [PATCH 0/4] pinctrl: pinctrl-zynqmp: Add tri-state configuration support

[Michal Simek]

Hi Laurent,

On 9/28/22 18:42, Laurent Pinchart wrote:
> 
> On Wed, Sep 28, 2022 at 06:58:10PM +0300, Laurent Pinchart wrote:
>> Hi Sai,
>>
>> On Fri, Jun 17, 2022 at 04:16:55PM +0530, Sai Krishna Potthuri wrote:
>>> This series update the Xilinx firmware, ZynqMP dt-binding and ZynqMP
>>> pinctrl driver to handle 'output-enable' and 'bias-high-impedance'
>>> configurations. As part of these configurations, ZynqMP pinctrl driver
>>> takes care of pin tri-state setting.
>>> Also fix the kernel doc warning in ZynqMP pinctrl driver.
>>
>> I'm afraid this causes a regression :-( With this series applied, boot
>> breaks with the following message being printed to the serial console:
>>
>> Received exception
>> MSR: 0x200, EAR: 0xFF180198, EDR: 0x0, ESR: 0x64
>>
>> I've traced that to the probe of the UART, when it calls into the
>> firmware to set pin MIO18 to high impedance. According to v1.7 of the
>> ZynqMP registers reference (UG1087), there is no register at address
>> 0xFF180198.
>>
>> I am using the VCU TRD 2021.1 for testing. Does this series require a
>> firmware update ? If so backward compatibility needs to be preserved.
>> It's very late in the v6.0-rc cycle for a fix, a revert may be best at
>> this point, to give us time to fix the issue properly.
> 
> I've now tested the VCU TRD 2022.1 (which AFAIK is the latest available
> version), and the problem doesn't occue then. It thus seems this depends
> on a firmware update, which is impractical at best for all old designs
> :-(

That's correct observation. Supporting these two properties requires newer pmufw 
or that message is received.
I will let Arun and Jyotheeswar to comment it. I don't think there is a way to 
detect which firmware has implementation for it available.

Thanks,
Michal

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RE: [PATCH 0/4] pinctrl: pinctrl-zynqmp: Add tri-state configuration support

[Kannan, Arun Balaji]

Hi Laurent,

We will be adding a way to check features that are available in firmware from kernel drivers in the near-future. Once that ability is available, kernel drivers can query if a feature is supported in the firmware before making use of the feature.

We will revert this patch at this time as existing (& older released) firmwares neither supports this particular pinctrl tristate feature or the ability to check for available features.

Regards,
Arun


> -----Original Message-----
> From: Simek, Michal <michal.simek@amd.com>
> Sent: Thursday, September 29, 2022 12:08 AM
> To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>; Sai Krishna
> Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>; Kannan, Arun Balaji
> <arun.balaji.kannan@amd.com>; Mutthareddyvari, Jyotheeswar Reddy
> <jyotheeswar.reddy.mutthareddyvari@amd.com>
> Cc: Linus Walleij <linus.walleij@linaro.org>; Rob Herring <robh+dt@kernel.org>;
> Michal Simek <michal.simek@xilinx.com>; Krzysztof Kozlowski
> <krzysztof.kozlowski+dt@linaro.org>; linux-arm-kernel@lists.infradead.org;
> linux-kernel@vger.kernel.org; devicetree@vger.kernel.org; linux-
> gpio@vger.kernel.org; git@xilinx.com; saikrishna12468@gmail.com
> Subject: Re: [PATCH 0/4] pinctrl: pinctrl-zynqmp: Add tri-state configuration
> support
> 
> Hi Laurent,
> 
> On 9/28/22 18:42, Laurent Pinchart wrote:
> >
> > On Wed, Sep 28, 2022 at 06:58:10PM +0300, Laurent Pinchart wrote:
> >> Hi Sai,
> >>
> >> On Fri, Jun 17, 2022 at 04:16:55PM +0530, Sai Krishna Potthuri wrote:
> >>> This series update the Xilinx firmware, ZynqMP dt-binding and ZynqMP
> >>> pinctrl driver to handle 'output-enable' and 'bias-high-impedance'
> >>> configurations. As part of these configurations, ZynqMP pinctrl
> >>> driver takes care of pin tri-state setting.
> >>> Also fix the kernel doc warning in ZynqMP pinctrl driver.
> >>
> >> I'm afraid this causes a regression :-( With this series applied,
> >> boot breaks with the following message being printed to the serial console:
> >>
> >> Received exception
> >> MSR: 0x200, EAR: 0xFF180198, EDR: 0x0, ESR: 0x64
> >>
> >> I've traced that to the probe of the UART, when it calls into the
> >> firmware to set pin MIO18 to high impedance. According to v1.7 of the
> >> ZynqMP registers reference (UG1087), there is no register at address
> >> 0xFF180198.
> >>
> >> I am using the VCU TRD 2021.1 for testing. Does this series require a
> >> firmware update ? If so backward compatibility needs to be preserved.
> >> It's very late in the v6.0-rc cycle for a fix, a revert may be best
> >> at this point, to give us time to fix the issue properly.
> >
> > I've now tested the VCU TRD 2022.1 (which AFAIK is the latest
> > available version), and the problem doesn't occue then. It thus seems
> > this depends on a firmware update, which is impractical at best for
> > all old designs :-(
> 
> That's correct observation. Supporting these two properties requires newer
> pmufw or that message is received.
> I will let Arun and Jyotheeswar to comment it. I don't think there is a way to
> detect which firmware has implementation for it available.
> 
> Thanks,
> Michal
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