Re: [PATCH v10 4/4] [media] platform: Add Synopsys DesignWare HDMI RX Controller Driver

From: Jose Abreu
Date: Tue Dec 12 2017 - 11:02:24 EST


Hi Hans,

On 12-12-2017 15:47, Hans Verkuil wrote:
> Hi Jose,
>
> Some more comments:

Thanks for the review!

>
> On 11/12/17 18:41, Jose Abreu wrote:
>> This is an initial submission for the Synopsys DesignWare HDMI RX
>> Controller Driver. This driver interacts with a phy driver so that
>> a communication between them is created and a video pipeline is
>> configured.
>>
>> The controller + phy pipeline can then be integrated into a fully
>> featured system that can be able to receive video up to 4k@60Hz
>> with deep color 48bit RGB, depending on the platform. Although,
>> this initial version does not yet handle deep color modes.
>>
>> This driver was implemented as a standard V4L2 subdevice and its
>> main features are:
>> - Internal state machine that reconfigures phy until the
>> video is not stable
>> - JTAG communication with phy
>> - Inter-module communication with phy driver
>> - Debug write/read ioctls
>>
>> Some notes:
>> - RX sense controller (cable connection/disconnection) must
>> be handled by the platform wrapper as this is not integrated
>> into the controller RTL
>> - The same goes for EDID ROM's
>> - ZCAL calibration is needed only in FPGA platforms, in ASIC
>> this is not needed
>> - The state machine is not an ideal solution as it creates a
>> kthread but it is needed because some sources might not be
>> very stable at sending the video (i.e. we must react
>> accordingly).
>>
>> Signed-off-by: Jose Abreu <joabreu@xxxxxxxxxxxx>
>> Cc: Joao Pinto <jpinto@xxxxxxxxxxxx>
>> Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
>> Cc: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>> Cc: Sylwester Nawrocki <snawrocki@xxxxxxxxxx>
>> Cc: Sakari Ailus <sakari.ailus@xxxxxx>
>> Cc: Philippe Ombredanne <pombredanne@xxxxxxxx>
>> ---
>> Changes from v9:
>> - Use SPDX License ID (Philippe)
>> - Use LOW_DRIVE CEC error (Hans)
>> - Fill bt->il_* fields (Hans)
>> - Fix format->field to NONE (Hans)
>> - Drop a left-over comment (Hans)
>> - Use CEC_CAP_DEFAULTS (Hans)
>> Changes from v8:
>> - Incorporate Sakari's work on ASYNC subdevs
>> Changes from v6:
>> - edid-phandle now also looks for parent node (Sylwester)
>> - Fix kbuild build warnings
>> Changes from v5:
>> - Removed HDCP 1.4 support (Hans)
>> - Removed some CEC debug messages (Hans)
>> - Add s_dv_timings callback (Hans)
>> - Add V4L2_CID_DV_RX_POWER_PRESENT ctrl (Hans)
>> Changes from v4:
>> - Add flag V4L2_SUBDEV_FL_HAS_DEVNODE (Sylwester)
>> - Remove some comments and change some messages to dev_dbg (Sylwester)
>> - Use v4l2_async_subnotifier_register() (Sylwester)
>> Changes from v3:
>> - Use v4l2 async API (Sylwester)
>> - Do not block waiting for phy
>> - Do not use busy waiting delays (Sylwester)
>> - Simplify dw_hdmi_power_on (Sylwester)
>> - Use clock API (Sylwester)
>> - Use compatible string (Sylwester)
>> - Minor fixes (Sylwester)
>> Changes from v2:
>> - Address review comments from Hans regarding CEC
>> - Use CEC notifier
>> - Enable SCDC
>> Changes from v1:
>> - Add support for CEC
>> - Correct typo errors
>> - Correctly detect interlaced video modes
>> - Correct VIC parsing
>> Changes from RFC:
>> - Add support for HDCP 1.4
>> - Fixup HDMI_VIC not being parsed (Hans)
>> - Send source change signal when powering off (Hans)
>> - Add a "wait stable delay"
>> - Detect interlaced video modes (Hans)
>> - Restrain g/s_register from reading/writing to HDCP regs (Hans)
>> ---
>> drivers/media/platform/dwc/Kconfig | 15 +
>> drivers/media/platform/dwc/Makefile | 1 +
>> drivers/media/platform/dwc/dw-hdmi-rx.c | 1840 +++++++++++++++++++++++++++++++
>> drivers/media/platform/dwc/dw-hdmi-rx.h | 419 +++++++
>> include/media/dwc/dw-hdmi-rx-pdata.h | 48 +
>> 5 files changed, 2323 insertions(+)
>> create mode 100644 drivers/media/platform/dwc/dw-hdmi-rx.c
>> create mode 100644 drivers/media/platform/dwc/dw-hdmi-rx.h
>> create mode 100644 include/media/dwc/dw-hdmi-rx-pdata.h
>>
>> diff --git a/drivers/media/platform/dwc/Kconfig b/drivers/media/platform/dwc/Kconfig
>> index 361d38d..3ddccde 100644
>> --- a/drivers/media/platform/dwc/Kconfig
>> +++ b/drivers/media/platform/dwc/Kconfig
>> @@ -6,3 +6,18 @@ config VIDEO_DWC_HDMI_PHY_E405
>>
>> To compile this driver as a module, choose M here. The module
>> will be called dw-hdmi-phy-e405.
>> +
>> +config VIDEO_DWC_HDMI_RX
>> + tristate "Synopsys Designware HDMI Receiver driver"
>> + depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API
>> + help
>> + Support for Synopsys Designware HDMI RX controller.
>> +
>> + To compile this driver as a module, choose M here. The module
>> + will be called dw-hdmi-rx.
>> +
>> +config VIDEO_DWC_HDMI_RX_CEC
>> + bool
>> + depends on VIDEO_DWC_HDMI_RX
>> + select CEC_CORE
>> + select CEC_NOTIFIER
>> diff --git a/drivers/media/platform/dwc/Makefile b/drivers/media/platform/dwc/Makefile
>> index fc3b62c..cd04ca9 100644
>> --- a/drivers/media/platform/dwc/Makefile
>> +++ b/drivers/media/platform/dwc/Makefile
>> @@ -1 +1,2 @@
>> obj-$(CONFIG_VIDEO_DWC_HDMI_PHY_E405) += dw-hdmi-phy-e405.o
>> +obj-$(CONFIG_VIDEO_DWC_HDMI_RX) += dw-hdmi-rx.o
>> diff --git a/drivers/media/platform/dwc/dw-hdmi-rx.c b/drivers/media/platform/dwc/dw-hdmi-rx.c
>> new file mode 100644
>> index 0000000..437351e
>> --- /dev/null
>> +++ b/drivers/media/platform/dwc/dw-hdmi-rx.c
> <snip>
>
>> +static int dw_hdmi_s_routing(struct v4l2_subdev *sd, u32 input, u32 output,
>> + u32 config)
>> +{
>> + struct dw_hdmi_dev *dw_dev = to_dw_dev(sd);
>> +
>> + if (!has_signal(dw_dev, input))
>> + return -EINVAL;
> Why would this be a reason to reject this? There may be no signal now, but a signal
> might appear later.

I would expect s_routing to only be called if there is an input
connected, otherwise we are just wasting resources by trying to
equalize an input that is not present ... I can remove the "if"
as there are other safe guards for this though (for example g_fmt
will return an error) ...

>
>> +
>> + dw_dev->selected_input = input;
>> + if (input == dw_dev->configured_input)
>> + return 0;
>> +
>> + dw_hdmi_power_off(dw_dev);
>> + return dw_hdmi_power_on(dw_dev, input);
>> +}
>> +
>> +static int dw_hdmi_g_input_status(struct v4l2_subdev *sd, u32 *status)
>> +{
>> + struct dw_hdmi_dev *dw_dev = to_dw_dev(sd);
>> +
>> + *status = 0;
>> + if (!has_signal(dw_dev, dw_dev->selected_input))
>> + *status |= V4L2_IN_ST_NO_POWER;
>> + if (is_off(dw_dev))
>> + *status |= V4L2_IN_ST_NO_SIGNAL;
>> +
>> + dev_dbg(dw_dev->dev, "%s: status=0x%x\n", __func__, *status);
>> + return 0;
>> +}
>> +
>> +static int dw_hdmi_g_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parm)
>> +{
>> + struct dw_hdmi_dev *dw_dev = to_dw_dev(sd);
>> +
>> + dev_dbg(dw_dev->dev, "%s\n", __func__);
>> +
>> + /* TODO: Use helper to compute timeperframe */
>> + parm->parm.capture.timeperframe.numerator = 1;
>> + parm->parm.capture.timeperframe.denominator = 60;
>> + return 0;
>> +}
>> +
>> +static int dw_hdmi_s_dv_timings(struct v4l2_subdev *sd,
>> + struct v4l2_dv_timings *timings)
>> +{
>> + struct dw_hdmi_dev *dw_dev = to_dw_dev(sd);
>> +
>> + dev_dbg(dw_dev->dev, "%s\n", __func__);
>> + if (!v4l2_valid_dv_timings(timings, &dw_hdmi_timings_cap, NULL, NULL))
>> + return -EINVAL;
>> + if (v4l2_match_dv_timings(timings, &dw_dev->timings, 0, false))
>> + return 0;
>> +
>> + dw_dev->timings = *timings;
>> + return 0;
>> +}
>> +
>> +static int dw_hdmi_g_dv_timings(struct v4l2_subdev *sd,
>> + struct v4l2_dv_timings *timings)
>> +{
>> + struct dw_hdmi_dev *dw_dev = to_dw_dev(sd);
>> +
>> + dev_dbg(dw_dev->dev, "%s\n", __func__);
>> +
>> + *timings = dw_dev->timings;
>> + return 0;
>> +}
>> +
>> +static int dw_hdmi_query_dv_timings(struct v4l2_subdev *sd,
>> + struct v4l2_dv_timings *timings)
>> +{
>> + struct dw_hdmi_dev *dw_dev = to_dw_dev(sd);
>> + struct v4l2_bt_timings *bt = &timings->bt;
>> + bool is_hdmi_vic;
>> + u32 htot, hofs;
>> + u32 vtot;
>> + u8 vic;
>> +
>> + dev_dbg(dw_dev->dev, "%s\n", __func__);
>> +
>> + memset(timings, 0, sizeof(*timings));
>> +
>> + timings->type = V4L2_DV_BT_656_1120;
>> + bt->width = hdmi_readl(dw_dev, HDMI_MD_HACT_PX);
>> + bt->height = hdmi_readl(dw_dev, HDMI_MD_VAL);
>> + bt->interlaced = hdmi_readl(dw_dev, HDMI_MD_STS) & HDMI_MD_STS_ILACE ?
>> + V4L2_DV_INTERLACED : V4L2_DV_PROGRESSIVE;
>> +
>> + if (hdmi_readl(dw_dev, HDMI_ISTS) & HDMI_ISTS_VS_POL_ADJ)
>> + bt->polarities |= V4L2_DV_VSYNC_POS_POL;
>> + if (hdmi_readl(dw_dev, HDMI_ISTS) & HDMI_ISTS_HS_POL_ADJ)
>> + bt->polarities |= V4L2_DV_HSYNC_POS_POL;
>> +
>> + bt->pixelclock = dw_hdmi_get_pixelclk(dw_dev);
>> +
>> + /* HTOT = HACT + HFRONT + HSYNC + HBACK */
>> + htot = hdmi_mask_readl(dw_dev, HDMI_MD_HT1,
>> + HDMI_MD_HT1_HTOT_PIX_OFFSET,
>> + HDMI_MD_HT1_HTOT_PIX_MASK);
>> + /* HOFS = HSYNC + HBACK */
>> + hofs = hdmi_mask_readl(dw_dev, HDMI_MD_HT1,
>> + HDMI_MD_HT1_HOFS_PIX_OFFSET,
>> + HDMI_MD_HT1_HOFS_PIX_MASK);
>> +
>> + bt->hfrontporch = htot - hofs - bt->width;
>> + bt->hsync = hdmi_mask_readl(dw_dev, HDMI_MD_HT0,
>> + HDMI_MD_HT0_HS_CLK_OFFSET,
>> + HDMI_MD_HT0_HS_CLK_MASK);
>> + bt->hbackporch = hofs - bt->hsync;
>> +
>> + /* VTOT = VACT + VFRONT + VSYNC + VBACK */
>> + vtot = hdmi_readl(dw_dev, HDMI_MD_VTL);
>> +
>> + hdmi_mask_writel(dw_dev, 0x1, HDMI_MD_VCTRL,
>> + HDMI_MD_VCTRL_V_OFFS_LIN_MODE_OFFSET,
>> + HDMI_MD_VCTRL_V_OFFS_LIN_MODE_MASK);
>> + msleep(50); /* Wait for 1 field */
> How do you know this waits for 1 field? Or is this: "Wait for at least 1 field"?

Its wait at least for 1 field. This is over-generous because its
assuming the frame rate is 20fps (which in HDMI does not happen).

> I don't know exactly how the IP does this, but it looks fishy to me. If it is
> correct, then it could use a few comments about what is going on here as it is
> not obvious.

The IP updates the values at each field but I need to change this
register to populate all values in the bt struct.

>
> And what happens if the framerate is even slower? You know the pixelclock and
> total width+height, so you can calculate the framerate from that.

Hmm, but then I have to consider pixelclk error, msleep error, ...

>
>> + bt->vsync = hdmi_readl(dw_dev, HDMI_MD_VOL);
>> +
>> + hdmi_mask_writel(dw_dev, 0x0, HDMI_MD_VCTRL,
>> + HDMI_MD_VCTRL_V_OFFS_LIN_MODE_OFFSET,
>> + HDMI_MD_VCTRL_V_OFFS_LIN_MODE_MASK);
>> + msleep(50); /* Wait for 1 field */
>> + bt->vbackporch = hdmi_readl(dw_dev, HDMI_MD_VOL);
>> + bt->vfrontporch = vtot - bt->height - bt->vsync - bt->vbackporch;
>> +
>> + if (bt->interlaced == V4L2_DV_INTERLACED) {
>> + hdmi_mask_writel(dw_dev, 0x1, HDMI_MD_VCTRL,
>> + HDMI_MD_VCTRL_V_MODE_OFFSET,
>> + HDMI_MD_VCTRL_V_MODE_MASK);
>> + msleep(100); /* Wait for 2 fields */
>> +
>> + vtot = hdmi_readl(dw_dev, HDMI_MD_VTL);
>> + hdmi_mask_writel(dw_dev, 0x1, HDMI_MD_VCTRL,
>> + HDMI_MD_VCTRL_V_OFFS_LIN_MODE_OFFSET,
>> + HDMI_MD_VCTRL_V_OFFS_LIN_MODE_MASK);
>> + msleep(50); /* Wait for 1 field */
>> + bt->il_vsync = hdmi_readl(dw_dev, HDMI_MD_VOL);
>> +
>> + hdmi_mask_writel(dw_dev, 0x0, HDMI_MD_VCTRL,
>> + HDMI_MD_VCTRL_V_OFFS_LIN_MODE_OFFSET,
>> + HDMI_MD_VCTRL_V_OFFS_LIN_MODE_MASK);
>> + msleep(50);
>> + bt->il_vbackporch = hdmi_readl(dw_dev, HDMI_MD_VOL);
>> + bt->il_vfrontporch = vtot - bt->height - bt->il_vsync -
>> + bt->il_vbackporch;
>> +
>> + hdmi_mask_writel(dw_dev, 0x0, HDMI_MD_VCTRL,
>> + HDMI_MD_VCTRL_V_MODE_OFFSET,
>> + HDMI_MD_VCTRL_V_MODE_MASK);
> Same here, I'm not sure this is correct. What is the output of
> 'v4l2-ctl --query-dv-timings' when you feed it a standard interlaced format?

I used v4l2-ctl --log-status with interlaced format and
everything seemed correct ...

Thanks and Best Regards,
Jose Miguel Abreu

>
>> + }
>> +
>> + bt->standards = V4L2_DV_BT_STD_CEA861;
>> +
>> + vic = dw_hdmi_get_curr_vic(dw_dev, &is_hdmi_vic);
>> + if (vic) {
>> + if (is_hdmi_vic) {
>> + bt->flags |= V4L2_DV_FL_HAS_HDMI_VIC;
>> + bt->hdmi_vic = vic;
>> + bt->cea861_vic = 0;
>> + } else {
>> + bt->flags |= V4L2_DV_FL_HAS_CEA861_VIC;
>> + bt->hdmi_vic = 0;
>> + bt->cea861_vic = vic;
>> + }
>> + }
>> +
>> + return 0;
>> +}
> Regards,
>
> Hans
>