[0/4] Support HDMI CEC on Qualcomm SoCs

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. The equivalent
downstream driver also passed CEC CTS tests using a Quantum Data QD882E
analyzer.

Some registers bitfield definitions were added to make the code clearer,
and those will also be proposed for upstream in the original xml file
from which the header was generated, in the mesa project.

Note HDMI support is not yet included upstream for MSM8998, I would
appreciate if someone can verify this driver at least works on MSM8996,
for which adding the pinctrl nodes for CEC should be sufficient.

Signed-off-by: Arnaud Vrac <avrac@freebox.fr>
---
Arnaud Vrac (4):
      drm/msm: add some cec register bitfield details
      drm/msm: add hdmi cec support
      drm/msm: expose edid to hdmi cec adapter
      arm64: dts: qcom: msm8998: add hdmi cec pinctrl nodes

 arch/arm64/boot/dts/qcom/msm8998.dtsi  |  14 ++
 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.xml.h    |  62 +++++++-
 drivers/gpu/drm/msm/hdmi/hdmi_bridge.c |   2 +
 drivers/gpu/drm/msm/hdmi/hdmi_cec.c    | 280 +++++++++++++++++++++++++++++++++
 drivers/gpu/drm/msm/hdmi/hdmi_hpd.c    |  17 +-
 9 files changed, 412 insertions(+), 5 deletions(-)
---
base-commit: e3342532ecd39bbd9c2ab5b9001cec1589bc37e9
change-id: 20230418-msm8998-hdmi-cec-08b5890bf41e

Best regards,

On 18/04/2023 21:10, Arnaud Vrac wrote:
> The register names and bitfields were determined from the downstream
> msm-4.4 driver.
> 
> Signed-off-by: Arnaud Vrac <avrac@freebox.fr>
> ---
>   drivers/gpu/drm/msm/hdmi/hdmi.xml.h | 62 ++++++++++++++++++++++++++++++++++++-
>   1 file changed, 61 insertions(+), 1 deletion(-)

I have opened MR against Mesa at 
https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22588.

The patch is:

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Minor nit below

> 
> diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.xml.h b/drivers/gpu/drm/msm/hdmi/hdmi.xml.h
> index 973b460486a5a..b4dd6e8cba6b7 100644
> --- a/drivers/gpu/drm/msm/hdmi/hdmi.xml.h
> +++ b/drivers/gpu/drm/msm/hdmi/hdmi.xml.h
> @@ -76,6 +76,13 @@ enum hdmi_acr_cts {
>   	ACR_48 = 3,
>   };
>   
> +enum hdmi_cec_tx_status {
> +	CEC_TX_OK = 0,
> +	CEC_TX_NACK = 1,
> +	CEC_TX_ARB_LOSS = 2,
> +	CEC_TX_MAX_RETRIES = 3,
> +};
> +
>   #define REG_HDMI_CTRL						0x00000000
>   #define HDMI_CTRL_ENABLE					0x00000001
>   #define HDMI_CTRL_HDMI						0x00000002
> @@ -476,20 +483,73 @@ static inline uint32_t HDMI_DDC_REF_REFTIMER(uint32_t val)
>   #define REG_HDMI_HDCP_SW_LOWER_AKSV				0x00000288
>   
>   #define REG_HDMI_CEC_CTRL					0x0000028c
> +#define HDMI_CEC_CTRL_ENABLE					0x00000001
> +#define HDMI_CEC_CTRL_SEND_TRIGGER				0x00000002
> +#define HDMI_CEC_CTRL_FRAME_SIZE__MASK				0x000001f0
> +#define HDMI_CEC_CTRL_FRAME_SIZE__SHIFT				4
> +static inline uint32_t HDMI_CEC_CTRL_FRAME_SIZE(uint32_t val)
> +{
> +	return ((val) << HDMI_CEC_CTRL_FRAME_SIZE__SHIFT) & HDMI_CEC_CTRL_FRAME_SIZE__MASK;
> +}
> +#define HDMI_CEC_CTRL_LINE_OE					0x00000200
>   
>   #define REG_HDMI_CEC_WR_DATA					0x00000290
> +#define HDMI_CEC_WR_DATA_BROADCAST				0x00000001
> +#define HDMI_CEC_WR_DATA_DATA__MASK				0x0000ff00
> +#define HDMI_CEC_WR_DATA_DATA__SHIFT				8
> +static inline uint32_t HDMI_CEC_WR_DATA_DATA(uint32_t val)
> +{
> +	return ((val) << HDMI_CEC_WR_DATA_DATA__SHIFT) & HDMI_CEC_WR_DATA_DATA__MASK;
> +}
>   
> -#define REG_HDMI_CEC_CEC_RETRANSMIT				0x00000294
> +#define REG_HDMI_CEC_RETRANSMIT					0x00000294
> +#define HDMI_CEC_RETRANSMIT_ENABLE				0x00000001
> +#define HDMI_CEC_RETRANSMIT_COUNT__MASK				0x000000fe
> +#define HDMI_CEC_RETRANSMIT_COUNT__SHIFT			1
> +static inline uint32_t HDMI_CEC_RETRANSMIT_COUNT(uint32_t val)
> +{
> +	return ((val) << HDMI_CEC_RETRANSMIT_COUNT__SHIFT) & HDMI_CEC_RETRANSMIT_COUNT__MASK;
> +}
>   
>   #define REG_HDMI_CEC_STATUS					0x00000298
> +#define HDMI_CEC_STATUS_BUSY					0x00000001
> +#define HDMI_CEC_STATUS_TX_FRAME_DONE				0x00000008
> +#define HDMI_CEC_STATUS_TX_STATUS__MASK				0x000000f0
> +#define HDMI_CEC_STATUS_TX_STATUS__SHIFT			4
> +static inline uint32_t HDMI_CEC_STATUS_TX_STATUS(enum hdmi_cec_tx_status val)
> +{
> +	return ((val) << HDMI_CEC_STATUS_TX_STATUS__SHIFT) & HDMI_CEC_STATUS_TX_STATUS__MASK;
> +}
>   
>   #define REG_HDMI_CEC_INT					0x0000029c
> +#define HDMI_CEC_INT_TX_DONE					0x00000001
> +#define HDMI_CEC_INT_TX_DONE_MASK				0x00000002
> +#define HDMI_CEC_INT_TX_ERROR					0x00000004
> +#define HDMI_CEC_INT_TX_ERROR_MASK				0x00000008
> +#define HDMI_CEC_INT_MONITOR					0x00000010
> +#define HDMI_CEC_INT_MONITOR_MASK				0x00000020
> +#define HDMI_CEC_INT_RX_DONE					0x00000040
> +#define HDMI_CEC_INT_RX_DONE_MASK				0x00000080
>   
>   #define REG_HDMI_CEC_ADDR					0x000002a0
>   
>   #define REG_HDMI_CEC_TIME					0x000002a4
> +#define HDMI_CEC_TIME_ENABLE					0x00000001
> +#define HDMI_CEC_TIME_SIGNAL_FREE_TIME__MASK			0x0000ff80
> +#define HDMI_CEC_TIME_SIGNAL_FREE_TIME__SHIFT			7
> +static inline uint32_t HDMI_CEC_TIME_SIGNAL_FREE_TIME(uint32_t val)
> +{
> +	return ((val) << HDMI_CEC_TIME_SIGNAL_FREE_TIME__SHIFT) & HDMI_CEC_TIME_SIGNAL_FREE_TIME__MASK;
> +}
>   
>   #define REG_HDMI_CEC_REFTIMER					0x000002a8
> +#define HDMI_CEC_REFTIMER_ENABLE				0x00010000

I think this should come after the REFTIMER field.

> +#define HDMI_CEC_REFTIMER_REFTIMER__MASK			0x0000ffff
> +#define HDMI_CEC_REFTIMER_REFTIMER__SHIFT			0
> +static inline uint32_t HDMI_CEC_REFTIMER_REFTIMER(uint32_t val)
> +{
> +	return ((val) << HDMI_CEC_REFTIMER_REFTIMER__SHIFT) & HDMI_CEC_REFTIMER_REFTIMER__MASK;
> +}
>   
>   #define REG_HDMI_CEC_RD_DATA					0x000002ac
>   
>