[PATCH v2 1/2] platform: Add Amlogic Meson AO CEC Controller driver

On 07/27/2017 04:43 PM, Neil Armstrong wrote:

On 07/25/2017 03:45 PM, Hans Verkuil wrote:

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On 07/25/17 14:34, Neil Armstrong wrote:

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Hi Hans,

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+static int meson_ao_cec_probe(struct platform_device *pdev)
+{
+	struct meson_ao_cec_device *ao_cec;
+	struct platform_device *hdmi_dev;
+	struct device_node *np;
+	struct resource *res;
+	int ret, irq;
+
+	np = of_parse_phandle(pdev->dev.of_node, "hdmi-phandle", 0);
+	if (!np) {
+		dev_err(&pdev->dev, "Failed to find hdmi node\n");
+		return -ENODEV;
+	}
+
+	hdmi_dev = of_find_device_by_node(np);
+	if (hdmi_dev == NULL)
+		return -EPROBE_DEFER;
+
+	ao_cec = devm_kzalloc(&pdev->dev, sizeof(*ao_cec), GFP_KERNEL);
+	if (!ao_cec)
+		return -ENOMEM;
+
+	spin_lock_init(&ao_cec->cec_reg_lock);
+
+	ao_cec->notify = cec_notifier_get(&hdmi_dev->dev);
+	if (!ao_cec->notify)
+		return -ENOMEM;
+
+	ao_cec->adap = cec_allocate_adapter(&meson_ao_cec_ops, ao_cec,
+					    "meson_ao_cec",
+					    CEC_CAP_LOG_ADDRS |
+					    CEC_CAP_TRANSMIT |
+					    CEC_CAP_RC |
+					    CEC_CAP_PASSTHROUGH,
+					    1); /* Use 1 for now */

I recommend that you add support for 2 logical addresses. More isn't allowed
by the CEC 2.0 spec anyway (no such restriction for CEC 1.4, but more than
two really isn't needed).

I know, but in the "communication" register with the suspend/poweroff firmware
that  handles the wake up, only a single logical address is supported...

What should I do in this case ? Which logical adress should I pass to the firmware when implementing ir ?

Ah, OK. Interesting.

From cec-adap.c:

                if (log_addrs->num_log_addrs == 2) {
                        if (!(type_mask & ((1 << CEC_LOG_ADDR_TYPE_AUDIOSYSTEM) |
                                           (1 << CEC_LOG_ADDR_TYPE_TV)))) {
                                dprintk(1, "two LAs is only allowed for audiosystem and TV\n");
                                return -EINVAL;
                        }
                        if (!(type_mask & ((1 << CEC_LOG_ADDR_TYPE_PLAYBACK) |
                                           (1 << CEC_LOG_ADDR_TYPE_RECORD)))) {
                                dprintk(1, "an audiosystem/TV can only be combined with record or playback\n");
                                return -EINVAL;
                        }
                }

So you would store the TV or AUDIOSYSTEM logical address in the firmware, since those
describe the system best.

I.e. it is a TV/Audiosystem with recording/playback capabilities.

The problem is that for CEC 1.4 no such restriction is imposed (the test above is
specific to CEC 2.0). But I think it makes sense to just check if TV/Audiosystem
is selected and pick that as the LA to store in the firmware, and otherwise just
pick the first LA (log_addr[0]).

Ok I'll add support for dual LA, and I'll do this LA selection when I'll add firmware support.

Sorry, but having more than 1 LA makes the CEC controller very unstable, I'll need more info from amlogic to activate multiple LAs.

Neil

Thanks,
Neil

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Regards,

	Hans