On 08/04/2022 12:32, 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@xxxxxxx>
---
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 c8f44bcb298a..ab176401b727 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)
@@ -306,11 +310,44 @@ static int dw_hdmi_cec_remove(struct platform_device *pdev)
return 0;
}
+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 register */
+ 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 register */
+ 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 = dw_hdmi_cec_remove,
.driver = {
.name = "dw-hdmi-cec",
+ .pm = &dw_hdmi_cec_pm,
},
};
module_platform_driver(dw_hdmi_cec_driver);
As Hans said on v1, why don't you call dw_hdmi_cec_enable(cec->adap, false) in suspend and dw_hdmi_cec_enable(cec->adap, true) in resume ?
With this, CEC engine is not disabled on suspend.
Do you plan to use the engine from the suspend code ?
Neil
