[PATCH] drm: bridge: dw_hdmi: Add cec suspend/resume functions

[PATCH] drm: bridge: dw_hdmi: Add cec suspend/resume functions

[Sandor Yu]

CEC interrupt status/mask and logical address registers
will be reset when device enter suspend.
It will cause cec fail to work after device resume.
Add CEC suspend/resume functions, reinitialize logical address registers
and restore interrupt status/mask registers after resume.

Signed-off-by: Sandor Yu <Sandor.yu@nxp.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c | 37 +++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c
index 9389ce526eb13..be21c11de1f2a 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c
@@ -62,6 +62,10 @@ struct dw_hdmi_cec {
 	bool rx_done;
 	struct cec_notifier *notify;
 	int irq;
+
+	u8 regs_polarity;
+	u8 regs_mask;
+	u8 regs_mute_stat0;
 };
 
 static void dw_hdmi_write(struct dw_hdmi_cec *cec, u8 val, int offset)
@@ -304,11 +308,44 @@ static void dw_hdmi_cec_remove(struct platform_device *pdev)
 	cec_unregister_adapter(cec->adap);
 }
 
+static int __maybe_unused dw_hdmi_cec_resume(struct device *dev)
+{
+	struct dw_hdmi_cec *cec = dev_get_drvdata(dev);
+
+	/* Restore logical address */
+	dw_hdmi_write(cec, cec->addresses & 255, HDMI_CEC_ADDR_L);
+	dw_hdmi_write(cec, cec->addresses >> 8, HDMI_CEC_ADDR_H);
+
+	/* Restore interrupt status/mask registers */
+	dw_hdmi_write(cec, cec->regs_polarity, HDMI_CEC_POLARITY);
+	dw_hdmi_write(cec, cec->regs_mask, HDMI_CEC_MASK);
+	dw_hdmi_write(cec, cec->regs_mute_stat0, HDMI_IH_MUTE_CEC_STAT0);
+
+	return 0;
+}
+
+static int __maybe_unused dw_hdmi_cec_suspend(struct device *dev)
+{
+	struct dw_hdmi_cec *cec = dev_get_drvdata(dev);
+
+	/* store interrupt status/mask registers */
+	 cec->regs_polarity = dw_hdmi_read(cec, HDMI_CEC_POLARITY);
+	 cec->regs_mask = dw_hdmi_read(cec, HDMI_CEC_MASK);
+	 cec->regs_mute_stat0 = dw_hdmi_read(cec, HDMI_IH_MUTE_CEC_STAT0);
+
+	return 0;
+}
+
+static const struct dev_pm_ops dw_hdmi_cec_pm = {
+	SET_SYSTEM_SLEEP_PM_OPS(dw_hdmi_cec_suspend, dw_hdmi_cec_resume)
+};
+
 static struct platform_driver dw_hdmi_cec_driver = {
 	.probe	= dw_hdmi_cec_probe,
 	.remove_new = dw_hdmi_cec_remove,
 	.driver = {
 		.name = "dw-hdmi-cec",
+		.pm = &dw_hdmi_cec_pm,
 	},
 };
 module_platform_driver(dw_hdmi_cec_driver);
-- 
2.34.1

Re: [PATCH] drm: bridge: dw_hdmi: Add cec suspend/resume functions

[neil.armstrong]

On 21/07/2023 14:44, Sandor Yu wrote:
> CEC interrupt status/mask and logical address registers
> will be reset when device enter suspend.
> It will cause cec fail to work after device resume.
> Add CEC suspend/resume functions, reinitialize logical address registers
> and restore interrupt status/mask registers after resume.
> 
> Signed-off-by: Sandor Yu <Sandor.yu@nxp.com>
> ---
>   drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c | 37 +++++++++++++++++++
>   1 file changed, 37 insertions(+)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c
> index 9389ce526eb13..be21c11de1f2a 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c
> @@ -62,6 +62,10 @@ struct dw_hdmi_cec {
>   	bool rx_done;
>   	struct cec_notifier *notify;
>   	int irq;
> +
> +	u8 regs_polarity;
> +	u8 regs_mask;
> +	u8 regs_mute_stat0;
>   };
>   
>   static void dw_hdmi_write(struct dw_hdmi_cec *cec, u8 val, int offset)
> @@ -304,11 +308,44 @@ static void dw_hdmi_cec_remove(struct platform_device *pdev)
>   	cec_unregister_adapter(cec->adap);
>   }
>   
> +static int __maybe_unused dw_hdmi_cec_resume(struct device *dev)
> +{
> +	struct dw_hdmi_cec *cec = dev_get_drvdata(dev);
> +
> +	/* Restore logical address */
> +	dw_hdmi_write(cec, cec->addresses & 255, HDMI_CEC_ADDR_L);
> +	dw_hdmi_write(cec, cec->addresses >> 8, HDMI_CEC_ADDR_H);
> +
> +	/* Restore interrupt status/mask registers */
> +	dw_hdmi_write(cec, cec->regs_polarity, HDMI_CEC_POLARITY);
> +	dw_hdmi_write(cec, cec->regs_mask, HDMI_CEC_MASK);
> +	dw_hdmi_write(cec, cec->regs_mute_stat0, HDMI_IH_MUTE_CEC_STAT0);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused dw_hdmi_cec_suspend(struct device *dev)
> +{
> +	struct dw_hdmi_cec *cec = dev_get_drvdata(dev);
> +
> +	/* store interrupt status/mask registers */
> +	 cec->regs_polarity = dw_hdmi_read(cec, HDMI_CEC_POLARITY);
> +	 cec->regs_mask = dw_hdmi_read(cec, HDMI_CEC_MASK);
> +	 cec->regs_mute_stat0 = dw_hdmi_read(cec, HDMI_IH_MUTE_CEC_STAT0);
> +
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops dw_hdmi_cec_pm = {
> +	SET_SYSTEM_SLEEP_PM_OPS(dw_hdmi_cec_suspend, dw_hdmi_cec_resume)
> +};
> +
>   static struct platform_driver dw_hdmi_cec_driver = {
>   	.probe	= dw_hdmi_cec_probe,
>   	.remove_new = dw_hdmi_cec_remove,
>   	.driver = {
>   		.name = "dw-hdmi-cec",
> +		.pm = &dw_hdmi_cec_pm,
>   	},
>   };
>   module_platform_driver(dw_hdmi_cec_driver);

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>

Re: [PATCH] drm: bridge: dw_hdmi: Add cec suspend/resume functions

[Neil Armstrong]

Hi,

On Fri, 21 Jul 2023 20:44:15 +0800, Sandor Yu wrote:
> CEC interrupt status/mask and logical address registers
> will be reset when device enter suspend.
> It will cause cec fail to work after device resume.
> Add CEC suspend/resume functions, reinitialize logical address registers
> and restore interrupt status/mask registers after resume.
> 
> 
> [...]

Thanks, Applied to https://anongit.freedesktop.org/git/drm/drm-misc.git (drm-misc-next)

[1/1] drm: bridge: dw_hdmi: Add cec suspend/resume functions
      https://cgit.freedesktop.org/drm/drm-misc/commit/?id=db1184e410744a680f92ca21e5acd5ae54510db8

-- 
Neil