[PATCH 2/4] drm/msm: add hdmi cec support
Dmitry Baryshkov
dmitry.baryshkov at linaro.org
Thu Apr 20 09:03:08 UTC 2023
On Thu, 20 Apr 2023 at 10:24, Arnaud Vrac <avrac at freebox.fr> wrote:
>
> Le jeu. 20 avr. 2023 à 02:20, Dmitry Baryshkov
> <dmitry.baryshkov at linaro.org> a écrit :
> >
> > On 18/04/2023 21:10, Arnaud Vrac wrote:
> > > Some Qualcomm SoCs that support HDMI also support CEC, including MSM8996
> > > and MSM8998. The hardware block can handle a single CEC logical address
> > > and broadcast messages.
> > >
> > > Port the CEC driver from downstream msm-4.4 kernel. It has been tested
> > > on MSM8998 and passes the cec-compliance tool tests.
> > >
> > > Signed-off-by: Arnaud Vrac <avrac at freebox.fr>
> > > ---
> > > drivers/gpu/drm/msm/Kconfig | 8 ++
> > > drivers/gpu/drm/msm/Makefile | 1 +
> > > drivers/gpu/drm/msm/hdmi/hdmi.c | 15 ++
> > > drivers/gpu/drm/msm/hdmi/hdmi.h | 18 +++
> > > drivers/gpu/drm/msm/hdmi/hdmi_cec.c | 280 ++++++++++++++++++++++++++++++++++++
> > > 5 files changed, 322 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/msm/Kconfig b/drivers/gpu/drm/msm/Kconfig
> > > index 85f5ab1d552c4..2a02c74207935 100644
> > > --- a/drivers/gpu/drm/msm/Kconfig
> > > +++ b/drivers/gpu/drm/msm/Kconfig
> > > @@ -165,3 +165,11 @@ config DRM_MSM_HDMI_HDCP
> > > default y
> > > help
> > > Choose this option to enable HDCP state machine
> > > +
> > > +config DRM_MSM_HDMI_CEC
> > > + bool "Enable HDMI CEC support in MSM DRM driver"
> > > + depends on DRM_MSM && DRM_MSM_HDMI
> > > + select CEC_CORE
> > > + default y
> > > + help
> > > + Choose this option to enable CEC support
> > > diff --git a/drivers/gpu/drm/msm/Makefile b/drivers/gpu/drm/msm/Makefile
> > > index 7274c41228ed9..0237a2f219ac2 100644
> > > --- a/drivers/gpu/drm/msm/Makefile
> > > +++ b/drivers/gpu/drm/msm/Makefile
> > > @@ -131,6 +131,7 @@ msm-$(CONFIG_DRM_MSM_DP)+= dp/dp_aux.o \
> > >
> > > msm-$(CONFIG_DRM_FBDEV_EMULATION) += msm_fbdev.o
> > >
> > > +msm-$(CONFIG_DRM_MSM_HDMI_CEC) += hdmi/hdmi_cec.o
> > > msm-$(CONFIG_DRM_MSM_HDMI_HDCP) += hdmi/hdmi_hdcp.o
> > >
> > > msm-$(CONFIG_DRM_MSM_DSI) += dsi/dsi.o \
> > > diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.c b/drivers/gpu/drm/msm/hdmi/hdmi.c
> > > index 3132105a2a433..1dde3890e25c0 100644
> > > --- a/drivers/gpu/drm/msm/hdmi/hdmi.c
> > > +++ b/drivers/gpu/drm/msm/hdmi/hdmi.c
> > > @@ -11,6 +11,8 @@
> > > #include <drm/drm_bridge_connector.h>
> > > #include <drm/drm_of.h>
> > >
> > > +#include <media/cec.h>
> > > +
> > > #include <sound/hdmi-codec.h>
> > > #include "hdmi.h"
> > >
> > > @@ -53,6 +55,9 @@ static irqreturn_t msm_hdmi_irq(int irq, void *dev_id)
> > > if (hdmi->hdcp_ctrl)
> > > msm_hdmi_hdcp_irq(hdmi->hdcp_ctrl);
> > >
> > > + /* Process CEC: */
> > > + msm_hdmi_cec_irq(hdmi);
> > > +
> > > /* TODO audio.. */
> > >
> > > return IRQ_HANDLED;
> > > @@ -66,6 +71,8 @@ static void msm_hdmi_destroy(struct hdmi *hdmi)
> > > */
> > > if (hdmi->workq)
> > > destroy_workqueue(hdmi->workq);
> > > +
> > > + msm_hdmi_cec_exit(hdmi);
> > > msm_hdmi_hdcp_destroy(hdmi);
> > >
> > > if (hdmi->i2c)
> > > @@ -139,6 +146,8 @@ static int msm_hdmi_init(struct hdmi *hdmi)
> > > hdmi->hdcp_ctrl = NULL;
> > > }
> > >
> > > + msm_hdmi_cec_init(hdmi);
> > > +
> > > return 0;
> > >
> > > fail:
> > > @@ -198,6 +207,12 @@ int msm_hdmi_modeset_init(struct hdmi *hdmi,
> > >
> > > drm_connector_attach_encoder(hdmi->connector, hdmi->encoder);
> > >
> > > + if (hdmi->cec_adap) {
> > > + struct cec_connector_info conn_info;
> > > + cec_fill_conn_info_from_drm(&conn_info, hdmi->connector);
> > > + cec_s_conn_info(hdmi->cec_adap, &conn_info);
> > > + }
> > > +
> > > ret = devm_request_irq(dev->dev, hdmi->irq,
> > > msm_hdmi_irq, IRQF_TRIGGER_HIGH,
> > > "hdmi_isr", hdmi);
> > > diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.h b/drivers/gpu/drm/msm/hdmi/hdmi.h
> > > index e8dbee50637fa..c639bd87f4b8f 100644
> > > --- a/drivers/gpu/drm/msm/hdmi/hdmi.h
> > > +++ b/drivers/gpu/drm/msm/hdmi/hdmi.h
> > > @@ -29,6 +29,7 @@ struct hdmi_audio {
> > > };
> > >
> > > struct hdmi_hdcp_ctrl;
> > > +struct cec_adapter;
> > >
> > > struct hdmi {
> > > struct drm_device *dev;
> > > @@ -73,6 +74,7 @@ struct hdmi {
> > > struct workqueue_struct *workq;
> > >
> > > struct hdmi_hdcp_ctrl *hdcp_ctrl;
> > > + struct cec_adapter *cec_adap;
> > >
> > > /*
> > > * spinlock to protect registers shared by different execution
> > > @@ -261,4 +263,20 @@ static inline void msm_hdmi_hdcp_off(struct hdmi_hdcp_ctrl *hdcp_ctrl) {}
> > > static inline void msm_hdmi_hdcp_irq(struct hdmi_hdcp_ctrl *hdcp_ctrl) {}
> > > #endif
> > >
> > > +/*
> > > + * cec
> > > + */
> > > +#ifdef CONFIG_DRM_MSM_HDMI_CEC
> > > +int msm_hdmi_cec_init(struct hdmi *hdmi);
> > > +void msm_hdmi_cec_exit(struct hdmi *hdmi);
> > > +void msm_hdmi_cec_irq(struct hdmi *hdmi);
> > > +#else
> > > +static inline int msm_hdmi_cec_init(struct hdmi *hdmi)
> > > +{
> > > + return -ENXIO;
> > > +}
> > > +static inline void msm_hdmi_cec_exit(struct hdmi *hdmi) {}
> > > +static inline void msm_hdmi_cec_irq(struct hdmi *hdmi) {}
> > > +#endif
> > > +
> > > #endif /* __HDMI_CONNECTOR_H__ */
> > > diff --git a/drivers/gpu/drm/msm/hdmi/hdmi_cec.c b/drivers/gpu/drm/msm/hdmi/hdmi_cec.c
> > > new file mode 100644
> > > index 0000000000000..51326e493e5da
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/msm/hdmi/hdmi_cec.c
> > > @@ -0,0 +1,280 @@
> > > +#include <linux/iopoll.h>
> > > +#include <media/cec.h>
> > > +
> > > +#include "hdmi.h"
> > > +
> > > +#define HDMI_CEC_INT_MASK ( \
> > > + HDMI_CEC_INT_TX_DONE_MASK | \
> > > + HDMI_CEC_INT_TX_ERROR_MASK | \
> > > + HDMI_CEC_INT_RX_DONE_MASK)
> > > +
> > > +struct hdmi_cec_ctrl {
> > > + struct hdmi *hdmi;
> > > + struct work_struct work;
> > > + spinlock_t lock;
> > > + u32 irq_status;
> > > + u32 tx_status;
> > > + u32 tx_retransmits;
> > > +};
> > > +
> > > +static int msm_hdmi_cec_adap_enable(struct cec_adapter *adap, bool enable)
> > > +{
> > > + struct hdmi_cec_ctrl *cec_ctrl = adap->priv;
> > > + struct hdmi *hdmi = cec_ctrl->hdmi;
> > > +
> > > + if (enable) {
> > > + /* timer frequency, 19.2Mhz * 0.05ms / 1000ms = 960 */
> > > + hdmi_write(hdmi, REG_HDMI_CEC_REFTIMER,
> > > + HDMI_CEC_REFTIMER_REFTIMER(960) |
> > > + HDMI_CEC_REFTIMER_ENABLE);
> > > +
> > > + /* read and write timings */
> > > + hdmi_write(hdmi, REG_HDMI_CEC_RD_RANGE, 0x30AB9888);
> >
> > lowercase hex please. We are trying to switch to it.
> >
> > > + hdmi_write(hdmi, REG_HDMI_CEC_WR_RANGE, 0x888AA888);
> > > + hdmi_write(hdmi, REG_HDMI_CEC_RD_START_RANGE, 0x88888888);
> > > + hdmi_write(hdmi, REG_HDMI_CEC_RD_TOTAL_RANGE, 0x99);
> > > +
> > > + /* start bit low pulse duration, 3.7ms */
> > > + hdmi_write(hdmi, REG_HDMI_CEC_RD_ERR_RESP_LO, 74);
> > > +
> > > + /* signal free time, 7 * 2.4ms */
> > > + hdmi_write(hdmi, REG_HDMI_CEC_TIME,
> > > + HDMI_CEC_TIME_SIGNAL_FREE_TIME(7 * 48) |
> > > + HDMI_CEC_TIME_ENABLE);
> > > +
> > > + hdmi_write(hdmi, REG_HDMI_CEC_COMPL_CTL, 0xF);
> > > + hdmi_write(hdmi, REG_HDMI_CEC_WR_CHECK_CONFIG, 0x4);
> > > + hdmi_write(hdmi, REG_HDMI_CEC_RD_FILTER, BIT(0) | (0x7FF << 4));
> > > +
> > > + hdmi_write(hdmi, REG_HDMI_CEC_INT, HDMI_CEC_INT_MASK);
> > > + hdmi_write(hdmi, REG_HDMI_CEC_CTRL, HDMI_CEC_CTRL_ENABLE);
> > > + } else {
> > > + hdmi_write(hdmi, REG_HDMI_CEC_INT, 0);
> > > + hdmi_write(hdmi, REG_HDMI_CEC_CTRL, 0);
> > > + cancel_work_sync(&cec_ctrl->work);
> > > + }
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int msm_hdmi_cec_adap_log_addr(struct cec_adapter *adap, u8 logical_addr)
> > > +{
> > > + struct hdmi_cec_ctrl *cec_ctrl = adap->priv;
> > > + struct hdmi *hdmi = cec_ctrl->hdmi;
> > > +
> > > + hdmi_write(hdmi, REG_HDMI_CEC_ADDR, logical_addr & 0xF);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int msm_hdmi_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
> > > + u32 signal_free_time, struct cec_msg *msg)
> > > +{
> > > + struct hdmi_cec_ctrl *cec_ctrl = adap->priv;
> > > + struct hdmi *hdmi = cec_ctrl->hdmi;
> > > + u8 retransmits;
> > > + u32 broadcast;
> > > + u32 status;
> > > + int i;
> > > +
> > > + /* toggle cec in order to flush out bad hw state, if any */
> > > + hdmi_write(hdmi, REG_HDMI_CEC_CTRL, 0);
> > > + hdmi_write(hdmi, REG_HDMI_CEC_CTRL, HDMI_CEC_CTRL_ENABLE);
> > > +
> > > + /* flush register writes */
> > > + wmb();
> > > +
> > > + retransmits = attempts ? (attempts - 1) : 0;
> > > + hdmi_write(hdmi, REG_HDMI_CEC_RETRANSMIT,
> > > + HDMI_CEC_RETRANSMIT_ENABLE |
> > > + HDMI_CEC_RETRANSMIT_COUNT(retransmits));
> > > +
> > > + broadcast = cec_msg_is_broadcast(msg) ? HDMI_CEC_WR_DATA_BROADCAST : 0;
> > > + for (i = 0; i < msg->len; i++) {
> > > + hdmi_write(hdmi, REG_HDMI_CEC_WR_DATA,
> > > + HDMI_CEC_WR_DATA_DATA(msg->msg[i]) | broadcast);
> > > + }
> > > +
> > > + /* check line status */
> > > + if (read_poll_timeout(hdmi_read, status, !(status & HDMI_CEC_STATUS_BUSY),
> > > + 5, 1000, false, hdmi, REG_HDMI_CEC_STATUS)) {
> > > + pr_err("CEC line is busy. Retry failed\n");
> > > + return -EBUSY;
> > > + }
> > > +
> > > + cec_ctrl->tx_retransmits = retransmits;
> > > +
> > > + /* start transmission */
> > > + hdmi_write(hdmi, REG_HDMI_CEC_CTRL,
> > > + HDMI_CEC_CTRL_ENABLE |
> > > + HDMI_CEC_CTRL_SEND_TRIGGER |
> > > + HDMI_CEC_CTRL_FRAME_SIZE(msg->len) |
> > > + HDMI_CEC_CTRL_LINE_OE);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static void msm_hdmi_cec_adap_free(struct cec_adapter *adap)
> > > +{
> > > + struct hdmi_cec_ctrl *cec_ctrl = adap->priv;
> > > +
> > > + cec_ctrl->hdmi->cec_adap = NULL;
> > > + kfree(cec_ctrl);
> > > +}
> > > +
> > > +static const struct cec_adap_ops msm_hdmi_cec_adap_ops = {
> > > + .adap_enable = msm_hdmi_cec_adap_enable,
> > > + .adap_log_addr = msm_hdmi_cec_adap_log_addr,
> > > + .adap_transmit = msm_hdmi_cec_adap_transmit,
> > > + .adap_free = msm_hdmi_cec_adap_free,
> > > +};
> > > +
> > > +#define CEC_IRQ_FRAME_WR_DONE 0x01
> > > +#define CEC_IRQ_FRAME_RD_DONE 0x02
> >
> > Please move these to top. Also you might consider replacing this mask
> > with two boolean flags.
> >
> > > +
> > > +static void msm_hdmi_cec_handle_rx_done(struct hdmi_cec_ctrl *cec_ctrl)
> > > +{
> > > + struct hdmi *hdmi = cec_ctrl->hdmi;
> > > + struct cec_msg msg = {};
> > > + u32 data;
> > > + int i;
> > > +
> > > + data = hdmi_read(hdmi, REG_HDMI_CEC_RD_DATA);
> > > + msg.len = (data & 0x1f00) >> 8;
> >
> > We can also use FIELD_GET here. I'll add defines to the mesa merge request.
>
> Ok, I wasn't sure if it made sense to add the bitfield definition for
> this since it's only valid for the first byte of the message. I'll add
> the change since this has been integrated into mesa.
>
> >
> > > + if (msg.len < 1 || msg.len > CEC_MAX_MSG_SIZE)
> > > + return;
> > > +
> > > + msg.msg[0] = data & 0xff;
> > > + for (i = 1; i < msg.len; i++)
> > > + msg.msg[i] = hdmi_read(hdmi, REG_HDMI_CEC_RD_DATA) & 0xff;
> > > +
> > > + cec_received_msg(hdmi->cec_adap, &msg);
> > > +}
> > > +
> > > +static void msm_hdmi_cec_handle_tx_done(struct hdmi_cec_ctrl *cec_ctrl)
> > > +{
> > > + struct hdmi *hdmi = cec_ctrl->hdmi;
> > > + u32 tx_status;
> > > +
> > > + tx_status = (cec_ctrl->tx_status & HDMI_CEC_STATUS_TX_STATUS__MASK) >>
> > > + HDMI_CEC_STATUS_TX_STATUS__SHIFT;
> >
> > FIELD_GET(HDMI_CEC_STATUS_TX_STATUS__MASK, cec_ctrl->tx_status).
> >
> > > +
> > > + switch (tx_status) {
> > > + case 0:
> >
> > Please use valus from enum hdmi_cec_tx_status
> >
> > > + cec_transmit_done(hdmi->cec_adap,
> > > + CEC_TX_STATUS_OK, 0, 0, 0, 0);
> > > + break;
> > > + case 1:
> > > + cec_transmit_done(hdmi->cec_adap,
> > > + CEC_TX_STATUS_NACK, 0, 1, 0, 0);
> > > + break;
> > > + case 2:
> > > + cec_transmit_done(hdmi->cec_adap,
> > > + CEC_TX_STATUS_ARB_LOST, 1, 0, 0, 0);
> > > + break;
> > > + case 3:
> > > + cec_transmit_done(hdmi->cec_adap,
> > > + CEC_TX_STATUS_MAX_RETRIES |
> > > + CEC_TX_STATUS_NACK,
> > > + 0, cec_ctrl->tx_retransmits + 1, 0, 0);
> > > + break;
> > > + default:
> > > + cec_transmit_done(hdmi->cec_adap,
> > > + CEC_TX_STATUS_ERROR, 0, 0, 0, 1);
> > > + break;
> > > + }
> > > +}
> > > +
> > > +static void msm_hdmi_cec_work(struct work_struct *work)
> > > +{
> > > + struct hdmi_cec_ctrl *cec_ctrl =
> > > + container_of(work, struct hdmi_cec_ctrl, work);
> > > + unsigned long flags;
> > > +
> > > + spin_lock_irqsave(&cec_ctrl->lock, flags);
> > > +
> > > + if (cec_ctrl->irq_status & CEC_IRQ_FRAME_WR_DONE)
> > > + msm_hdmi_cec_handle_tx_done(cec_ctrl);
> > > +
> > > + if (cec_ctrl->irq_status & CEC_IRQ_FRAME_RD_DONE)
> > > + msm_hdmi_cec_handle_rx_done(cec_ctrl);
> > > +
> > > + cec_ctrl->irq_status = 0;
> > > + cec_ctrl->tx_status = 0;
> > > +
> > > + spin_unlock_irqrestore(&cec_ctrl->lock, flags);
> > > +}
> > > +
> > > +void msm_hdmi_cec_irq(struct hdmi *hdmi)
> > > +{
> > > + struct hdmi_cec_ctrl *cec_ctrl;
> > > + unsigned long flags;
> > > + u32 int_status;
> > > +
> > > + if (!hdmi->cec_adap)
> > > + return;
> > > +
> > > + cec_ctrl = hdmi->cec_adap->priv;
> > > +
> > > + int_status = hdmi_read(hdmi, REG_HDMI_CEC_INT);
> > > + if (!(int_status & HDMI_CEC_INT_MASK))
> > > + return;
> > > +
> > > + spin_lock_irqsave(&cec_ctrl->lock, flags);
> > > +
> > > + if (int_status & (HDMI_CEC_INT_TX_DONE | HDMI_CEC_INT_TX_ERROR)) {
> > > + cec_ctrl->tx_status = hdmi_read(hdmi, REG_HDMI_CEC_STATUS);
> > > + cec_ctrl->irq_status |= CEC_IRQ_FRAME_WR_DONE;
> > > + }
> > > +
> > > + if (int_status & HDMI_CEC_INT_RX_DONE)
> > > + cec_ctrl->irq_status |= CEC_IRQ_FRAME_RD_DONE;
> > > +
> > > + spin_unlock_irqrestore(&cec_ctrl->lock, flags);
> > > +
> > > + hdmi_write(hdmi, REG_HDMI_CEC_INT, int_status);
> > > + queue_work(hdmi->workq, &cec_ctrl->work);
> > > +}
> > > +
> > > +int msm_hdmi_cec_init(struct hdmi *hdmi)
> > > +{
> > > + struct platform_device *pdev = hdmi->pdev;
> > > + struct hdmi_cec_ctrl *cec_ctrl;
> > > + struct cec_adapter *cec_adap;
> > > + int ret;
> >
> > hdmi_cec_enable from msm-4.4 tells that CEC is not supported if
> > REG_HDMI_VERSION reads < 0x30000001. Could you please add this check?
>
> Ack. I wonder which SoCs before MSM8996 can actually support CEC.
Granted the commit at [1], one can assume that apq8084 supported CEC
and it even wasn't the first one.
[1] https://git.codelinaro.org/clo/la/kernel/msm-3.10/-/commit/8d8640d18491660f8c6bd082fd2030e2d7cbc1f8
I checked, on apq8064 this register reads as 0x2010000. I'd guess the
first chips to support CEC were msm8974/apq8074
>
> >
> >
> >
> >
> > > +
> > > + cec_ctrl = kzalloc(sizeof (*cec_ctrl), GFP_KERNEL);
> > > + if (!cec_ctrl)
> > > + return -ENOMEM;
> > > +
> > > + cec_ctrl->hdmi = hdmi;
> > > + INIT_WORK(&cec_ctrl->work, msm_hdmi_cec_work);
> > > +
> > > + cec_adap = cec_allocate_adapter(&msm_hdmi_cec_adap_ops,
> > > + cec_ctrl, "msm",
> > > + CEC_CAP_DEFAULTS |
> > > + CEC_CAP_CONNECTOR_INFO, 1);
> > > + ret = PTR_ERR_OR_ZERO(cec_adap);
> > > + if (ret < 0) {
> > > + kfree(cec_ctrl);
> > > + return ret;
> > > + }
> > > +
> > > + /* Set the logical address to Unregistered */
> > > + hdmi_write(hdmi, REG_HDMI_CEC_ADDR, 0xf);
> > > +
> > > + ret = cec_register_adapter(cec_adap, &pdev->dev);
> > > + if (ret < 0) {
> > > + cec_delete_adapter(cec_adap);
> > > + return ret;
> > > + }
> > > +
> > > + hdmi->cec_adap = cec_adap;
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +void msm_hdmi_cec_exit(struct hdmi *hdmi)
> > > +{
> > > + cec_unregister_adapter(hdmi->cec_adap);
> > > +}
--
With best wishes
Dmitry
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