[PATCHv6 1/3] drm: add support for DisplayPort CEC-Tunneling-over-AUX
Ville Syrjälä
ville.syrjala at linux.intel.com
Wed Jun 27 17:57:12 UTC 2018
On Tue, Jun 12, 2018 at 01:18:29PM +0200, Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil at cisco.com>
>
> This adds support for the DisplayPort CEC-Tunneling-over-AUX
> feature that is part of the DisplayPort 1.3 standard.
>
> Unfortunately, not all DisplayPort/USB-C to HDMI adapters with a
> chip that has this capability actually hook up the CEC pin, so
> even though a CEC device is created, it may not actually work.
>
> Signed-off-by: Hans Verkuil <hans.verkuil at cisco.com>
> ---
> drivers/gpu/drm/Kconfig | 10 +
> drivers/gpu/drm/Makefile | 1 +
> drivers/gpu/drm/drm_dp_cec.c | 423 ++++++++++++++++++++++++++++++++
> drivers/gpu/drm/drm_dp_helper.c | 1 +
> include/drm/drm_dp_helper.h | 56 +++++
> 5 files changed, 491 insertions(+)
> create mode 100644 drivers/gpu/drm/drm_dp_cec.c
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index deeefa7a1773..d63876425cdc 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -121,6 +121,16 @@ config DRM_LOAD_EDID_FIRMWARE
> default case is N. Details and instructions how to build your own
> EDID data are given in Documentation/EDID/HOWTO.txt.
>
> +config DRM_DP_CEC
> + bool "Enable DisplayPort CEC-Tunneling-over-AUX HDMI support"
> + select CEC_CORE
> + help
> + Choose this option if you want to enable HDMI CEC support for
> + DisplayPort/USB-C to HDMI adapters.
> +
> + Note: not all adapters support this feature, and even for those
> + that do support this they often do not hook up the CEC pin.
> +
> config DRM_TTM
> tristate
> depends on DRM && MMU
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 50093ff4479b..c787481c2502 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -41,6 +41,7 @@ drm_kms_helper-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o
> drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o
> drm_kms_helper-$(CONFIG_DRM_KMS_CMA_HELPER) += drm_fb_cma_helper.o
> drm_kms_helper-$(CONFIG_DRM_DP_AUX_CHARDEV) += drm_dp_aux_dev.o
> +drm_kms_helper-$(CONFIG_DRM_DP_CEC) += drm_dp_cec.o
>
> obj-$(CONFIG_DRM_KMS_HELPER) += drm_kms_helper.o
> obj-$(CONFIG_DRM_DEBUG_MM_SELFTEST) += selftests/
> diff --git a/drivers/gpu/drm/drm_dp_cec.c b/drivers/gpu/drm/drm_dp_cec.c
> new file mode 100644
> index 000000000000..555a9fca3fef
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_dp_cec.c
> @@ -0,0 +1,423 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * DisplayPort CEC-Tunneling-over-AUX support
> + *
> + * Copyright 2018 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <drm/drm_dp_helper.h>
> +#include <media/cec.h>
> +
> +/*
> + * Unfortunately it turns out that we have a chicken-and-egg situation
> + * here. Quite a few active (mini-)DP-to-HDMI or USB-C-to-HDMI adapters
> + * have a converter chip that supports CEC-Tunneling-over-AUX (usually the
> + * Parade PS176), but they do not wire up the CEC pin, thus making CEC
> + * useless.
> + *
> + * Sadly there is no way for this driver to know this. What happens is
> + * that a /dev/cecX device is created that is isolated and unable to see
> + * any of the other CEC devices. Quite literally the CEC wire is cut
> + * (or in this case, never connected in the first place).
> + *
> + * The reason so few adapters support this is that this tunneling protocol
> + * was never supported by any OS. So there was no easy way of testing it,
> + * and no incentive to correctly wire up the CEC pin.
> + *
> + * Hopefully by creating this driver it will be easier for vendors to
> + * finally fix their adapters and test the CEC functionality.
> + *
> + * I keep a list of known working adapters here:
> + *
> + * https://hverkuil.home.xs4all.nl/cec-status.txt
> + *
> + * Please mail me (hverkuil at xs4all.nl) if you find an adapter that works
> + * and is not yet listed there.
> + *
> + * Note that the current implementation does not support CEC over an MST hub.
> + * As far as I can see there is no mechanism defined in the DisplayPort
> + * standard to transport CEC interrupts over an MST device. It might be
> + * possible to do this through polling, but I have not been able to get that
> + * to work.
> + */
> +
> +/**
> + * DOC: dp cec helpers
> + *
> + * These functions take care of supporting the CEC-Tunneling-over-AUX
> + * feature of DisplayPort-to-HDMI adapters.
> + */
> +
> +/*
> + * When the EDID is unset because the HPD went low, then the CEC DPCD registers
> + * typically can no longer be read (true for a DP-to-HDMI adapter since it is
> + * powered by the HPD). However, some displays toggle the HPD off and on for a
> + * short period for one reason or another, and that would cause the CEC adapter
> + * to be removed and added again, even though nothing else changed.
> + *
> + * This module parameter sets a delay in seconds before the CEC adapter is
> + * actually unregistered. Only if the HPD does not return within that time will
> + * the CEC adapter be unregistered.
And whatever is trying to do cec is happy with the dpcd accesses
failing during that time?
> + *
> + * If it is set to 0, then the CEC adapter will never be unregistered for as
> + * long as the connector remains registered.
> + *
> + * Note that for integrated HDMI branch devices that support CEC the DPCD
> + * registers remain available even if the HPD goes low since it is not powered
> + * by the HPD. In that case the CEC adapter will never be unregistered during
> + * the life time of the connector. At least, this is the theory since I do not
> + * have hardware with an integrated HDMI branch device that supports CEC.
> + */
> +static unsigned int drm_dp_cec_unregister_delay = 1;
> +module_param(drm_dp_cec_unregister_delay, uint, 0600);
> +MODULE_PARM_DESC(drm_dp_cec_unregister_delay, "CEC unregister delay in seconds, 0 == never unregister");
> +
> +static int drm_dp_cec_adap_enable(struct cec_adapter *adap, bool enable)
> +{
> + struct drm_dp_aux *aux = cec_get_drvdata(adap);
> + u32 val = enable ? DP_CEC_TUNNELING_ENABLE : 0;
> + ssize_t err = 0;
> +
> + err = drm_dp_dpcd_writeb(aux, DP_CEC_TUNNELING_CONTROL, val);
> + return (enable && err < 0) ? err : 0;
> +}
> +
> +static int drm_dp_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
> +I think I looked at the dpcd detais last time around. {
> + struct drm_dp_aux *aux = cec_get_drvdata(adap);
> + /* Bit 15 (logical address 15) should always be set */
> + u16 la_mask = 1 << CEC_LOG_ADDR_BROADCAST;
> + u8 mask[2];
> + ssize_t err;
> +
> + if (addr != CEC_LOG_ADDR_INVALID)
> + la_mask |= adap->log_addrs.log_addr_mask | (1 << addr);
> + mask[0] = la_mask & 0xff;
> + mask[1] = la_mask >> 8;
> + err = drm_dp_dpcd_write(aux, DP_CEC_LOGICAL_ADDRESS_MASK, mask, 2);
> + return (addr != CEC_LOG_ADDR_INVALID && err < 0) ? err : 0;
> +}
> +
> +static int drm_dp_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
> + u32 signal_free_time, struct cec_msg *msg)
'msg' could be const perhaps?
> +{
> + struct drm_dp_aux *aux = cec_get_drvdata(adap);
> + unsigned int retries = min(5, attempts - 1);
> + ssize_t err;
> +
> + err = drm_dp_dpcd_write(aux, DP_CEC_TX_MESSAGE_BUFFER,
> + msg->msg, msg->len);
> + if (err < 0)
> + return err;
> +
> + err = drm_dp_dpcd_writeb(aux, DP_CEC_TX_MESSAGE_INFO,
> + (msg->len - 1) | (retries << 4) |
> + DP_CEC_TX_MESSAGE_SEND);
> + return err < 0 ? err : 0;
> +}
> +
> +static int drm_dp_cec_adap_monitor_all_enable(struct cec_adapter *adap,
> + bool enable)
> +{
> + struct drm_dp_aux *aux = cec_get_drvdata(adap);
> + ssize_t err;
> + u8 val;
> +
> + if (!(adap->capabilities & CEC_CAP_MONITOR_ALL))
> + return 0;
> +
> + err = drm_dp_dpcd_readb(aux, DP_CEC_TUNNELING_CONTROL, &val);
> + if (err >= 0) {
> + if (enable)
> + val |= DP_CEC_SNOOPING_ENABLE;
> + else
> + val &= ~DP_CEC_SNOOPING_ENABLE;
> + err = drm_dp_dpcd_writeb(aux, DP_CEC_TUNNELING_CONTROL, val);
> + }
> + return (enable && err < 0) ? err : 0;
> +}
> +
> +static void drm_dp_cec_adap_status(struct cec_adapter *adap,
> + struct seq_file *file)
> +{
> + struct drm_dp_aux *aux = cec_get_drvdata(adap);
> + struct drm_dp_desc desc;
> + struct drm_dp_dpcd_ident *id = &desc.ident;
> +
> + if (drm_dp_read_desc(aux, &desc, true))
> + return;
> + seq_printf(file, "OUI: %*pdH\n",
> + (int)sizeof(id->oui), id->oui);
> + seq_printf(file, "ID: %*pE\n",
> + (int)strnlen(id->device_id, sizeof(id->device_id)),
> + id->device_id);
> + seq_printf(file, "HW Rev: %d.%d\n", id->hw_rev >> 4, id->hw_rev & 0xf);
> + /*
> + * Show this both in decimal and hex: at least one vendor
> + * always reports this in hex.
> + */
> + seq_printf(file, "FW/SW Rev: %d.%d (0x%02x.0x%02x)\n",
> + id->sw_major_rev, id->sw_minor_rev,
> + id->sw_major_rev, id->sw_minor_rev);
> +}
> +
> +static const struct cec_adap_ops drm_dp_cec_adap_ops = {
> + .adap_enable = drm_dp_cec_adap_enable,
> + .adap_log_addr = drm_dp_cec_adap_log_addr,
> + .adap_transmit = drm_dp_cec_adap_transmit,
> + .adap_monitor_all_enable = drm_dp_cec_adap_monitor_all_enable,
> + .adap_status = drm_dp_cec_adap_status,
> +};
> +
> +static int drm_dp_cec_received(struct drm_dp_aux *aux)
> +{
> + struct cec_adapter *adap = aux->cec_adap;
> + struct cec_msg msg;
> + u8 rx_msg_info;
> + ssize_t err;
> +
> + err = drm_dp_dpcd_readb(aux, DP_CEC_RX_MESSAGE_INFO, &rx_msg_info);
> + if (err < 0)
> + return err;
> +
> + if (!(rx_msg_info & DP_CEC_RX_MESSAGE_ENDED))
> + return 0;
> +
> + msg.len = (rx_msg_info & DP_CEC_RX_MESSAGE_LEN_MASK) + 1;
> + err = drm_dp_dpcd_read(aux, DP_CEC_RX_MESSAGE_BUFFER, msg.msg, msg.len);
> + if (err < 0)
> + return err;
> +
> + cec_received_msg(adap, &msg);
> + return 0;
> +}
> +
> +static void drm_dp_cec_handle_irq(struct drm_dp_aux *aux)
> +{
> + struct cec_adapter *adap = aux->cec_adap;
> + u8 flags;
> +
> + if (drm_dp_dpcd_readb(aux, DP_CEC_TUNNELING_IRQ_FLAGS, &flags) < 0)
> + return;
> +
> + if (flags & DP_CEC_RX_MESSAGE_INFO_VALID)
> + drm_dp_cec_received(aux);
> +
> + if (flags & DP_CEC_TX_MESSAGE_SENT)
> + cec_transmit_attempt_done(adap, CEC_TX_STATUS_OK);
> + else if (flags & DP_CEC_TX_LINE_ERROR)
> + cec_transmit_attempt_done(adap, CEC_TX_STATUS_ERROR |
> + CEC_TX_STATUS_MAX_RETRIES);
> + else if (flags &
> + (DP_CEC_TX_ADDRESS_NACK_ERROR | DP_CEC_TX_DATA_NACK_ERROR))
> + cec_transmit_attempt_done(adap, CEC_TX_STATUS_NACK |
> + CEC_TX_STATUS_MAX_RETRIES);
> + drm_dp_dpcd_writeb(aux, DP_CEC_TUNNELING_IRQ_FLAGS, flags);
> +}
> +
> +/**
> + * drm_dp_cec_irq() - handle CEC interrupt, if any
> + * @aux: DisplayPort AUX channel
> + *
> + * Should be called when handling an IRQ_HPD request. If CEC-tunneling-over-AUX
> + * is present, then it will check for a CEC_IRQ and handle it accordingly.
> + */
> +void drm_dp_cec_irq(struct drm_dp_aux *aux)
> +{
> + u8 cec_irq;
> + int ret;
> +
> + mutex_lock(&aux->cec_mutex);
> + if (!aux->cec_adap)
> + goto unlock;
> +
> + ret = drm_dp_dpcd_readb(aux, DP_DEVICE_SERVICE_IRQ_VECTOR_ESI1,
> + &cec_irq);
> + if (ret < 0 || !(cec_irq & DP_CEC_IRQ))
> + goto unlock;
> +
> + drm_dp_cec_handle_irq(aux);
> + drm_dp_dpcd_writeb(aux, DP_DEVICE_SERVICE_IRQ_VECTOR_ESI1, DP_CEC_IRQ);
> +unlock:
> + mutex_unlock(&aux->cec_mutex);
> +}
> +EXPORT_SYMBOL(drm_dp_cec_irq);
> +
> +static bool drm_dp_cec_cap(struct drm_dp_aux *aux, u8 *cec_cap)
> +{
> + u8 cap = 0;
> +
> + if (drm_dp_dpcd_readb(aux, DP_CEC_TUNNELING_CAPABILITY, &cap) != 1 ||
> + !(cap & DP_CEC_TUNNELING_CAPABLE))
> + return false;
> + if (cec_cap)
> + *cec_cap = cap;
> + return true;
> +}
> +
> +/*
> + * Called if the HPD was low for more than drm_dp_cec_unregister_delay
> + * seconds. This unregisters the CEC adapter.
> + */
> +static void drm_dp_cec_unregister_work(struct work_struct *work)
> +{
> + struct drm_dp_aux *aux = container_of(work, struct drm_dp_aux,
> + cec_unregister_work.work);
> +
> + if (!aux->cec_adap)
> + return;
> + mutex_lock(&aux->cec_mutex);
> + cec_unregister_adapter(aux->cec_adap);
> + aux->cec_adap = NULL;
> + mutex_unlock(&aux->cec_mutex);
> +}
> +
> +/*
> + * A new EDID is set. If there is no CEC adapter, then create one. If
> + * there was a CEC adapter, then check if the CEC adapter properties
> + * were unchanged and just update the CEC physical address. Otherwise
> + * unregister the old CEC adapter and create a new one.
> + */
> +void drm_dp_cec_set_edid(struct drm_dp_aux *aux, struct edid *edid)
'edid' can be const.
> +{
> + u32 cec_caps = CEC_CAP_DEFAULTS | CEC_CAP_NEEDS_HPD;
> + unsigned int num_las = 1;
> + u8 cap;
> +
> +#ifndef CONFIG_MEDIA_CEC_RC
> + /*
> + * CEC_CAP_RC is part of CEC_CAP_DEFAULTS, but it is stripped by
> + * cec_allocate_adapter() if CONFIG_MEDIA_CEC_RC is undefined.
> + *
> + * Do this here as well to ensure the tests against cec_caps are
> + * correct.
> + */
> + cec_caps &= ~CEC_CAP_RC;
> +#endif
> + cancel_delayed_work_sync(&aux->cec_unregister_work);
> +
> + mutex_lock(&aux->cec_mutex);
> + if (!drm_dp_cec_cap(aux, &cap)) {
> + /* CEC is not supported, unregister any existing adapter */
> + cec_unregister_adapter(aux->cec_adap);
> + aux->cec_adap = NULL;
> + goto unlock;
> + }
> +
> + if (cap & DP_CEC_SNOOPING_CAPABLE)
> + cec_caps |= CEC_CAP_MONITOR_ALL;
> + if (cap & DP_CEC_MULTIPLE_LA_CAPABLE)
> + num_las = CEC_MAX_LOG_ADDRS;
> +
> + if (aux->cec_adap) {
> + if (aux->cec_adap->capabilities == cec_caps &&
> + aux->cec_adap->available_log_addrs == num_las) {
> + /* Unchanged, so just set the phys addr */
> + cec_s_phys_addr_from_edid(aux->cec_adap, edid);
> + goto unlock;
> + }
> + /*
> + * The capabilities changed, so unregister the old
> + * adapter first.
> + */
> + cec_unregister_adapter(aux->cec_adap);
> + }
> +
> + /* Create a new adapter */
> + aux->cec_adap = cec_allocate_adapter(&drm_dp_cec_adap_ops,
> + aux, aux->cec_name, cec_caps,
> + num_las);
> + if (IS_ERR(aux->cec_adap)) {
> + aux->cec_adap = NULL;
> + goto unlock;
> + }
> + if (cec_register_adapter(aux->cec_adap, aux->cec_parent)) {
> + cec_delete_adapter(aux->cec_adap);
> + aux->cec_adap = NULL;
> + } else {
> + /*
> + * Update the phys addr for the new CEC adapter. When called
> + * from drm_dp_cec_register_connector() edid == NULL, so in
> + * that case the phys addr is just invalidated.
> + */
> + cec_s_phys_addr_from_edid(aux->cec_adap, edid);
> + }
> +unlock:
> + mutex_unlock(&aux->cec_mutex);
> +}
> +EXPORT_SYMBOL(drm_dp_cec_set_edid);
> +
> +/*
> + * The EDID disappeared (likely because of the HPD going down).
> + */
> +void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
> +{
> + mutex_lock(&aux->cec_mutex);
> + if (!aux->cec_adap)
> + goto unlock;
> + cec_phys_addr_invalidate(aux->cec_adap);
> + /*
> + * We're done if we want to keep the CEC device
> + * (drm_dp_cec_unregister_delay is 0) or if the DPCD still indicates
> + * the CEC capability (expected for an integrated HDMI branch device).
> + */
> + if (!drm_dp_cec_unregister_delay || drm_dp_cec_cap(aux, NULL))
> + goto unlock;
The drm_dp_cec_unregister_delay semantics seem a bit unnatural to me.
I think ==0 -> no delay, <0 -> infinite delay would make more sense.
Although we already have the exact opposite with the vblank_offdelay for
some historical reason :(
> +
> + cancel_delayed_work_sync(&aux->cec_unregister_work);
This looks like a potential deadlock to me.
> + if (aux->cec_adap) {
> + /* sanity check */
> + if (drm_dp_cec_unregister_delay > 600)
> + drm_dp_cec_unregister_delay = 600;
> + /*
> + * Unregister the CEC adapter after drm_dp_cec_unregister_delay
> + * seconds. This to debounce short HPD off-and-on cycles from
> + * displays.
> + */
> + schedule_delayed_work(&aux->cec_unregister_work,
> + drm_dp_cec_unregister_delay * HZ);
> + }
> +unlock:
> + mutex_unlock(&aux->cec_mutex);
> +}
> +EXPORT_SYMBOL(drm_dp_cec_unset_edid);
> +
> +/**
> + * drm_dp_cec_register_connector() - register a new connector
> + * @aux: DisplayPort AUX channel
> + * @name: name of the CEC device
> + * @parent: parent device
> + *
> + * A new connector was registered with associated CEC adapter name and
> + * CEC adapter parent device. After registering the name and parent
> + * drm_dp_cec_set_edid() is called to check if the connector supports
> + * CEC and to register a CEC adapter if that is the case.
> + */
> +void drm_dp_cec_register_connector(struct drm_dp_aux *aux, const char *name,
> + struct device *parent)
> +{
> + WARN_ON(aux->cec_adap);
> + aux->cec_name = name;
> + aux->cec_parent = parent;
> + INIT_DELAYED_WORK(&aux->cec_unregister_work, drm_dp_cec_unregister_work);
> +
> + drm_dp_cec_set_edid(aux, NULL);
> +}
> +EXPORT_SYMBOL(drm_dp_cec_register_connector);
> +
> +/**
> + * drm_dp_cec_unregister_connector() - unregister the CEC adapter, if any
> + * @aux: DisplayPort AUX channel
> + */
> +void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux)
> +{
> + if (!aux->cec_adap)
> + return;
> + cancel_delayed_work_sync(&aux->cec_unregister_work);
> + cec_unregister_adapter(aux->cec_adap);
> + aux->cec_adap = NULL;
> +}
> +EXPORT_SYMBOL(drm_dp_cec_unregister_connector);
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index ffe14ec3e7f2..e6b0e08ee0aa 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -1073,6 +1073,7 @@ static void drm_dp_aux_crc_work(struct work_struct *work)
> void drm_dp_aux_init(struct drm_dp_aux *aux)
> {
> mutex_init(&aux->hw_mutex);
> + mutex_init(&aux->cec_mutex);
> INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work);
>
> aux->ddc.algo = &drm_dp_i2c_algo;
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> index 62903bae0221..415ac52e8599 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -1062,6 +1062,9 @@ struct drm_dp_aux_msg {
> size_t size;
> };
>
> +struct cec_adapter;
> +struct edid;
> +
> /**
> * struct drm_dp_aux - DisplayPort AUX channel
> * @name: user-visible name of this AUX channel and the I2C-over-AUX adapter
> @@ -1120,6 +1123,26 @@ struct drm_dp_aux {
> * @i2c_defer_count: Counts I2C DEFERs, used for DP validation.
> */
> unsigned i2c_defer_count;
> + /**
> + * @cec_mutex: mutex protecting the cec_ fields
> + */
> + struct mutex cec_mutex;
> + /**
> + * @cec_adap: the CEC adapter for CEC-Tunneling-over-AUX support.
> + */
> + struct cec_adapter *cec_adap;
> + /**
> + * @cec_name: name of the CEC adapter
> + */
> + const char *cec_name;
> + /**
> + * @cec_parent: parent device of the CEC adapter
> + */
> + struct device *cec_parent;
> + /**
> + * @cec_unregister_work: unregister the CEC adapter
> + */
> + struct delayed_work cec_unregister_work;
'struct { ... } cec;' could be a decent idea here.
I think I looked at the dpcd detais last time around so I'll not bother
this time around with that. Apart from the possible deadlock I think
this is looking pretty good.
> };
>
> ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
> @@ -1242,4 +1265,37 @@ drm_dp_has_quirk(const struct drm_dp_desc *desc, enum drm_dp_quirk quirk)
> return desc->quirks & BIT(quirk);
> }
>
> +#ifdef CONFIG_DRM_DP_CEC
> +void drm_dp_cec_irq(struct drm_dp_aux *aux);
> +void drm_dp_cec_register_connector(struct drm_dp_aux *aux, const char *name,
> + struct device *parent);
> +void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux);
> +void drm_dp_cec_set_edid(struct drm_dp_aux *aux, struct edid *edid);
> +void drm_dp_cec_unset_edid(struct drm_dp_aux *aux);
> +#else
> +static inline void drm_dp_cec_irq(struct drm_dp_aux *aux)
> +{
> +}
> +
> +static inline void drm_dp_cec_register_connector(struct drm_dp_aux *aux,
> + const char *name,
> + struct device *parent)
> +{
> +}
> +
> +static inline void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux)
> +{
> +}
> +
> +static inline void drm_dp_cec_set_edid(struct drm_dp_aux *aux,
> + struct edid *edid)
> +{
> +}
> +
> +static inline void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
> +{
> +}
> +
> +#endif
> +
> #endif /* _DRM_DP_HELPER_H_ */
> --
> 2.17.0
--
Ville Syrjälä
Intel
More information about the dri-devel
mailing list