On Thu, Aug 11, 2016 at 02:14:10PM +0530, Sharma, Shashank wrote:
> Thanks for the review, Ville.
>
> My comments, inline.
>
> Regards
>
> Shashank
>
>
> On 8/11/2016 12:19 PM, Ville Syrjälä wrote:
> > On Tue, Jul 05, 2016 at 06:35:47PM +0530, Shashank Sharma wrote:
> >> This patch adds lspcon support in dp_dual_mode helper.
> >> lspcon is essentially a dp->hdmi dongle with dual personality.
> >>
> >> LS mode: It works as a passive dongle, by level shifting DP++
> >> signals to HDMI signals, in LS mode.
> >> PCON mode: It works as a protocol converter active dongle
> >> in pcon mode, by converting DP++ outputs to HDMI 2.0 outputs.
> >>
> >> This patch adds support for lspcon detection and mode set
> >> switch operations, as a dp dual mode dongle.
> >>
> >> v2: Addressed review comments from Ville
> >> - add adaptor id for lspcon devices (0x08), use it to identify lspcon
> >> - change function names
> >> old: drm_lspcon_get_current_mode/drm_lspcon_change_mode
> >> new: drm_lspcon_get_mode/drm_lspcon_set_mode
> >> - change drm_lspcon_get_mode type to int, to match
> >> drm_dp_dual_mode_get_tmds_output
> >> - change 'err' to 'ret' to match the rest of the functions
> >> - remove pointless typecasting during call to dual_mode_read
> >> - fix the but while setting value of data, while writing lspcon mode
> >> - fix indentation
> >> - change mdelay(10) -> msleep(10)
> >> - return ETIMEDOUT instead of EFAULT, when lspcon mode change times out
> >> - Add an empty line to separate std regs macros and lspcon regs macros
> >> Indent bit definition
> >>
> >> v3: Addressed review comments from Rodrigo
> >> - change macro name from DP_DUAL_MODE_TYPE_LSPCON to
> >> DP_DUAL_MODE_TYPE_HAS_DPCD for better readability
> >> - change macro name from DP_DUAL_MODE_LSPCON_MODE_PCON to
> >> DP_DUAL_MODE_LSPCON_MODE_PCON for better readability
> >> - add comment for MCA specific offsets like 0x40 and 0x41
> >> - remove DP_DUAL_MODE_REV_TYPE2 check while checking lspcon adapter id
> >>
> >> Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxxxx>
> >> ---
> >> drivers/gpu/drm/drm_dp_dual_mode_helper.c | 103 ++++++++++++++++++++++++++++++
> >> include/drm/drm_dp_dual_mode_helper.h | 26 ++++++++
> >> 2 files changed, 129 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/drm_dp_dual_mode_helper.c
> >> index a7b2a75..4f89e0b 100644
> >> --- a/drivers/gpu/drm/drm_dp_dual_mode_helper.c
> >> +++ b/drivers/gpu/drm/drm_dp_dual_mode_helper.c
> >> @@ -148,6 +148,14 @@ static bool is_type2_adaptor(uint8_t adaptor_id)
> >> DP_DUAL_MODE_REV_TYPE2);
> >> }
> >>
> >> +bool is_lspcon_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN],
> >> + const uint8_t adaptor_id)
> >> +{
> >> + return is_hdmi_adaptor(hdmi_id) &&
> >> + (adaptor_id == (DP_DUAL_MODE_TYPE_TYPE2 |
> >> + DP_DUAL_MODE_TYPE_HAS_DPCD));
> > Looks like an indent fail here.
> Can you please let me know, why do we call it indent fail ? checkpatch
> doesn't complaint about this.
Stuff should line up after the opening '('
> >> +}
> >> +
> >> /**
> >> * drm_dp_dual_mode_detect - Identify the DP dual mode adaptor
> >> * @adapter: I2C adapter for the DDC bus
> >> @@ -203,6 +211,8 @@ enum drm_dp_dual_mode_type drm_dp_dual_mode_detect(struct i2c_adapter *adapter)
> >> ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_ADAPTOR_ID,
> >> &adaptor_id, sizeof(adaptor_id));
> >> if (ret == 0) {
> >> + if (is_lspcon_adaptor(hdmi_id, adaptor_id))
> >> + return DRM_DP_DUAL_MODE_LSPCON;
> >> if (is_type2_adaptor(adaptor_id)) {
> >> if (is_hdmi_adaptor(hdmi_id))
> >> return DRM_DP_DUAL_MODE_TYPE2_HDMI;
> >> @@ -364,3 +374,96 @@ const char *drm_dp_get_dual_mode_type_name(enum drm_dp_dual_mode_type type)
> >> }
> >> }
> >> EXPORT_SYMBOL(drm_dp_get_dual_mode_type_name);
> >> +
> >> +/**
> >> + * drm_lspcon_get_current_mode: Get LSPCON's current mode of operation by
> >> + * by reading offset (0x80, 0x41)
> >> + * @i2c_adapter: I2C-over-aux adapter
> >> + * @current_mode: out vaiable, current lspcon mode of operation
> >> + *
> >> + * Returns:
> >> + * 0 on success, sets the current_mode value to appropriate mode
> >> + * -error on failure
> >> + */
> >> +int drm_lspcon_get_mode(struct i2c_adapter *adapter,
> >> + enum drm_lspcon_mode *current_mode)
> > indent fail, I would just call it 'mode'
> I wanted to be more informative about what is the out parameter, I
> though it makes it more readable
> that its returning current mode of lspcon. Would you still prefer to
> call it mode only ?
Yes, the fact that it's the current mode is pretty obvious.
> >> +{
> >> + u8 data;
> >> + int ret = 0;
> >> +
> >> + if (!current_mode) {
> >> + DRM_ERROR("NULL input\n");
> >> + return -EINVAL;
> >> + }
> >> +
> >> + /* Read Status: i2c over aux */
> >> + ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_LSPCON_CURRENT_MODE,
> >> + (void *)&data, sizeof(data));
> > indent fail, void* cast not needed.
> Sure, will remove void, same question on indent as above.
> >> + if (ret < 0) {
> >> + DRM_ERROR("LSPCON read(0x80, 0x41) failed\n");
> >> + return -EFAULT;
> >> + }
> >> +
> >> + if (data & DP_DUAL_MODE_LSPCON_MODE_PCON)
> >> + *current_mode = DRM_LSPCON_MODE_PCON;
> >> + else
> >> + *current_mode = DRM_LSPCON_MODE_LS;
> >> + return 0;
> >> +}
> >> +EXPORT_SYMBOL(drm_lspcon_get_mode);
> >> +
> >> +/**
> >> + * drm_lspcon_change_mode: Change LSPCON's mode of operation by
> >> + * by writing offset (0x80, 0x40)
> >> + * @i2c_adapter: I2C-over-aux adapter
> >> + * @reqd_mode: required mode of operation
> >> + *
> >> + * Returns:
> >> + * 0 on success, -error on failure/timeout
> >> + */
> >> +int drm_lspcon_set_mode(struct i2c_adapter *adapter,
> >> + enum drm_lspcon_mode reqd_mode)
> > indent fail, I would just call it 'mode'
> Same as above comments about indent.
> Now, this function deals with two modes:
> one which we wish to move to, and one which we get after mode change
> operation.
> The mode after mode change operation might not be the same as the one we
> wished for.
> So wouldn't it be better to make it clear by calling in reqd_mode ?
reqd_ looks line noise to me. You could spell it out properly, but still
looks like superfluous infromation to me. It's pretty clear from the
context.
> >> +{
> >> + u8 data = 0;
> >> + int ret;
> >> + int time_out = 200;
> >> + enum drm_lspcon_mode changed_mode;
> > This I might call 'current_mode'. The declaration can be moved inside
> > the loop.
> Sure, will do that.
> >> +
> >> + if (reqd_mode == DRM_LSPCON_MODE_PCON)
> >> + data = DP_DUAL_MODE_LSPCON_MODE_PCON;
> >> +
> >> + /* Change mode */
> >> + ret = drm_dp_dual_mode_write(adapter, DP_DUAL_MODE_LSPCON_MODE_CHANGE,
> >> + &data, sizeof(data));
> > indent fail.
> Same as above.
> >> + if (ret < 0) {
> >> + DRM_ERROR("LSPCON mode change failed\n");
> >> + return ret;
> >> + }
> >> +
> >> + /*
> >> + * Confirm mode change by reading the status bit.
> >> + * Sometimes, it takes a while to change the mode,
> >> + * so wait and retry until time out or done.
> >> + */
> >> + do {
> >> + ret = drm_lspcon_get_mode(adapter, &changed_mode);
> >> + if (ret) {
> >> + DRM_ERROR("cant confirm LSPCON mode change\n");
> >> + return ret;
> >> + } else {
> >> + if (changed_mode != reqd_mode) {
> >> + msleep(10);
> >> + time_out -= 10;
> >> + } else {
> >> + DRM_DEBUG_KMS("LSPCON mode changed to %s\n",
> >> + reqd_mode == DRM_LSPCON_MODE_LS ?
> >> + "LS" : "PCON");
> >> + return 0;
> >> + }
> >> + }
> >> + } while (time_out);
> >> +
> >> + DRM_ERROR("LSPCON mode change timed out\n");
> >> + return -ETIMEDOUT;
> >> +}
> >> +EXPORT_SYMBOL(drm_lspcon_set_mode);
> >> diff --git a/include/drm/drm_dp_dual_mode_helper.h b/include/drm/drm_dp_dual_mode_helper.h
> >> index e8a9dfd..a3c1d03 100644
> >> --- a/include/drm/drm_dp_dual_mode_helper.h
> >> +++ b/include/drm/drm_dp_dual_mode_helper.h
> >> @@ -24,6 +24,7 @@
> >> #define DRM_DP_DUAL_MODE_HELPER_H
> >>
> >> #include <linux/types.h>
> >> +#include <drm/drm_edid.h>
> > Why?
> Sorry, leftover. This was required in previous patch set to get the
> DDC_ADDR macro when we had separate EDID read function for LSPCON.
> Will remove this.
> >>
> >> /*
> >> * Optional for type 1 DVI adaptors
> >> @@ -40,6 +41,7 @@
> >> #define DP_DUAL_MODE_REV_TYPE2 0x00
> >> #define DP_DUAL_MODE_TYPE_MASK 0xf0
> >> #define DP_DUAL_MODE_TYPE_TYPE2 0xa0
> >> +#define DP_DUAL_MODE_TYPE_HAS_DPCD 0x08
> > Maybe add a comment that this came from LSPCON, and it's marked
> > reserved in the official dual mode spec.
> Ok, got it.
> >> #define DP_DUAL_MODE_IEEE_OUI 0x11 /* 11-13*/
> >> #define DP_DUAL_IEEE_OUI_LEN 3
> >> #define DP_DUAL_DEVICE_ID 0x14 /* 14-19 */
> >> @@ -55,6 +57,11 @@
> >> #define DP_DUAL_MODE_CEC_ENABLE 0x01
> >> #define DP_DUAL_MODE_I2C_SPEED_CTRL 0x22
> >>
> >> +/* LSPCON specific registers, defined by MCA */
> >> +#define DP_DUAL_MODE_LSPCON_MODE_CHANGE 0x40
> >> +#define DP_DUAL_MODE_LSPCON_CURRENT_MODE 0x41
> >> +#define DP_DUAL_MODE_LSPCON_MODE_PCON 0x1
> >> +
> >> struct i2c_adapter;
> >>
> >> ssize_t drm_dp_dual_mode_read(struct i2c_adapter *adapter,
> >> @@ -63,6 +70,19 @@ ssize_t drm_dp_dual_mode_write(struct i2c_adapter *adapter,
> >> u8 offset, const void *buffer, size_t size);
> >>
> >> /**
> >> +* enum drm_lspcon_mode
> >> +* @lspcon_mode_ls: Level shifter mode of LSPCON
> >> +* which drives DP++ to HDMI 1.4 conversion.
> >> +* @lspcon_mode_pcon: Protocol converter mode of LSPCON
> >> +* which drives DP++ to HDMI 2.0 active conversion.
> > These don't match the enum below.
> Ok, will fix it.
> >> +*/
> >> +enum drm_lspcon_mode {
> >> + DRM_LSPCON_MODE_INVALID,
> > Did we still have some need for this?
> Yes, lspcon probe failure case is using this.
That's already signalled via the return value, so not sure what extra
this gives us.
> >> + DRM_LSPCON_MODE_LS,
> >> + DRM_LSPCON_MODE_PCON,
> >> +};
> >> +
> >> +/**
> >> * enum drm_dp_dual_mode_type - Type of the DP dual mode adaptor
> >> * @DRM_DP_DUAL_MODE_NONE: No DP dual mode adaptor
> >> * @DRM_DP_DUAL_MODE_UNKNOWN: Could be either none or type 1 DVI adaptor
> >> @@ -70,6 +90,7 @@ ssize_t drm_dp_dual_mode_write(struct i2c_adapter *adapter,
> >> * @DRM_DP_DUAL_MODE_TYPE1_HDMI: Type 1 HDMI adaptor
> >> * @DRM_DP_DUAL_MODE_TYPE2_DVI: Type 2 DVI adaptor
> >> * @DRM_DP_DUAL_MODE_TYPE2_HDMI: Type 2 HDMI adaptor
> >> + * @DRM_DP_DUAL_MODE_TYPE2_LSPCON: Level shifter /protocol converter
> >> */
> >> enum drm_dp_dual_mode_type {
> >> DRM_DP_DUAL_MODE_NONE,
> >> @@ -78,6 +99,7 @@ enum drm_dp_dual_mode_type {
> >> DRM_DP_DUAL_MODE_TYPE1_HDMI,
> >> DRM_DP_DUAL_MODE_TYPE2_DVI,
> >> DRM_DP_DUAL_MODE_TYPE2_HDMI,
> >> + DRM_DP_DUAL_MODE_LSPCON,
> >> };
> >>
> >> enum drm_dp_dual_mode_type drm_dp_dual_mode_detect(struct i2c_adapter *adapter);
> >> @@ -89,4 +111,8 @@ int drm_dp_dual_mode_set_tmds_output(enum drm_dp_dual_mode_type type,
> >> struct i2c_adapter *adapter, bool enable);
> >> const char *drm_dp_get_dual_mode_type_name(enum drm_dp_dual_mode_type type);
> >>
> >> +int drm_lspcon_get_mode(struct i2c_adapter *adapter,
> >> + enum drm_lspcon_mode *current_mode);
> >> +int drm_lspcon_set_mode(struct i2c_adapter *adapter,
> >> + enum drm_lspcon_mode reqd_mode);
> > more indent fails.
> Same query as previous
>
> Regards
> Shashank
> >> #endif
> >> --
> >> 1.9.1
--
Ville Syrjälä
Intel OTC
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