[PATCH 2/4] drm/msm: add hdmi cec support
Arnaud Vrac
avrac at freebox.fr
Tue Apr 18 18:10:44 UTC 2023
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);
+ 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
+
+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;
+ 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;
+
+ switch (tx_status) {
+ case 0:
+ 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;
+
+ 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);
+}
--
2.40.0
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