On Tue, May 31, 2016 at 04:22:08PM +0530, Sharma, Shashank wrote:
> Thanks for the review, Ville.
> My comments, inline.
>
> Regards
> Shashank
> On 5/31/2016 3:22 PM, Ville Syrjälä wrote:
> > On Tue, May 31, 2016 at 02:55:42PM +0530, Shashank Sharma wrote:
> >> Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxxxx>
> >> ---
> >> drivers/gpu/drm/drm_dp_dual_mode_helper.c | 85 +++++++++++++++++++++++++++++++
> >> include/drm/drm_dp_dual_mode_helper.h | 29 +++++++++++
> >> 2 files changed, 114 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..11cab25 100644
> >> --- a/drivers/gpu/drm/drm_dp_dual_mode_helper.c
> >> +++ b/drivers/gpu/drm/drm_dp_dual_mode_helper.c
> >> @@ -148,6 +148,12 @@ 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 == 0xa8);
> >
> >
> > I'd probably make this something like
> >
> > #define DP_DUAL_MODE_RESERVED_LSPCON 0x08
> >
> > return adaptor_id == (DP_DUAL_MODE_TYPE_TYPE2 |
> > DP_DUAL_MODE_RESERVED_LSPCON |
> > DP_DUAL_MODE_REV_TYPE2);
> >
> Thanks, this is a good suggestion, I will do so.
> >
> >> +}
> >> +
> >> /**
> >> * drm_dp_dual_mode_detect - Identify the DP dual mode adaptor
> >> * @adapter: I2C adapter for the DDC bus
> >> @@ -203,6 +209,8 @@ 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 +372,80 @@ 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
> >> + *
> >> + * Returns:
> >> + * Enum representing current mode of operation
> >> + */
> >> +enum drm_lspcon_mode
> >> +drm_lspcon_get_current_mode(struct i2c_adapter *adapter)
> >
> > To match with drm_dp_dual_mode_get_tmds_output() this may want to
> > return the error status, and return the actual mode via a function
> > argument.
> >
> sure, can be done.
> > As for the name drm_dp_dual_mode_get_lspcon_mode() and
> > drm_dp_dual_mode_set_lspcon_mode() perhaps?
> > Or drm_lspcon_get_mode()/drm_lspcon_set_mode() perhaps if we want to
> > keep things shorter?
> >
> Yep, initially I made the same names as you suggested, but
> drm_dp_dual_mode_get_lspcon_mode dint sound good to me :).
> drm_lspcon_get/set_mode sounds good.
> >> +{
> >> + u8 data;
> >> + int err = 0;
> >
> > I used 'ret' in the rest of the code. This is a bit inconsistent.
> got it.
> >
> >> +
> >> + /* Read Status: i2c over aux */
> >> + err = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_LSPCON_CURRENT_MODE,
> >> + (void *)&data, sizeof(data));
> >
> > Pointless cast.
> >
> good catch, this is unnecessary.
> >> + if (err < 0) {
> >
> > if (ret) is what I've used elsewhere.
> got it.
> >
> >> + DRM_ERROR("LSPCON read(0x80, 0x41) failed\n");
> >
> > I'm not sure we want and ERROR from a helper. I used DRM_DEBUG_KMS for
> > the other error paths.
> >
> IMHO, This is a failure which needs notice, as it can point out to a HW
> level problem, or a problem in LSPCON FW, so I will prefer to keep it as
> error.
Fair enough.
> >> + return DRM_LSPCON_MODE_INVALID;
> >> + }
> >> +
> >> + return data & DP_DUAL_MODE_LSPCON_MODE_MASK ?
> >> + DRM_LSPCON_MODE_PCON : DRM_LSPCON_MODE_LS;
> >> +}
> >> +EXPORT_SYMBOL(drm_lspcon_get_current_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_change_mode(struct i2c_adapter *adapter,
> >> + enum drm_lspcon_mode reqd_mode)
> >> +{
> >> + u8 data;
> >> + int err;
> >> + int time_out = 200;
> >> +
> >> + if (reqd_mode == DRM_LSPCON_MODE_LS)
> >> + data = ~DP_DUAL_MODE_LSPCON_MODE_MASK;
> >
> > Is that really correct?
> >
> Oops, it was a blunder, but fortunately that register only bothers about
> bit 0, and that's why it worked, I will fix this.
> >> + else
> >> + data = DP_DUAL_MODE_LSPCON_MODE_MASK;
> >> +
> >> + /* Change mode */
> >> + err = drm_dp_dual_mode_write(adapter, DP_DUAL_MODE_LSPCON_MODE_CHANGE,
> >> + &data, sizeof(data));
> >> + if (err < 0) {
> >> + DRM_ERROR("LSPCON mode change failed\n");
> >> + return err;
> >> + }
> >> +
> >> + /*
> >> + * 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.
> >> + */
> >
> > indent fail
> OK.
> >
> >> + while (time_out) {
> >> + if (reqd_mode != drm_lspcon_get_current_mode(adapter)) {
> >> + mdelay(10);
> >
> > mdelay() is bad.
> Do you think I should replace with some of the non-busy wait (like
> msleep or so ?)
How long would we typically have to wait for the mode to change?
> >
> >> + time_out -= 10;
> >> + } else {
> >> + DRM_DEBUG_KMS("LSPCON mode changed to %s\n",
> >> + reqd_mode == DRM_LSPCON_MODE_LS ? "LS" : "PCON");
> >> + return 0;
> >> + }
> >> + }
> >> +
> >> + DRM_ERROR("LSPCON mode change timed out\n");
> >> + return -EFAULT;
> >
> > EFAULT doens't seem like a sensible error value here. ETIMEDOUT I
> > suppose seems like what we should return.
> Sure.
> >
> >> +}
> >> +EXPORT_SYMBOL(drm_lspcon_change_mode);
> >> diff --git a/include/drm/drm_dp_dual_mode_helper.h b/include/drm/drm_dp_dual_mode_helper.h
> >> index e8a9dfd..f335df5 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>
> >>
> >> /*
> >> * Optional for type 1 DVI adaptors
> >> @@ -54,6 +55,9 @@
> >> #define DP_DUAL_MODE_HDMI_PIN_CTRL 0x21
> >> #define DP_DUAL_MODE_CEC_ENABLE 0x01
> >> #define DP_DUAL_MODE_I2C_SPEED_CTRL 0x22
> >
> > Maybe leave an empty line here to separate the standard regs from the
> > vendor specific ones. Hmm. Actually the vendor register space is
> > 0x30-0x3f, whereas 0x40+ is reserved. But anyway empty line would
> > seem warranted.
> >
> Got it.
> >> +#define DP_DUAL_MODE_LSPCON_MODE_CHANGE 0x40
> >> +#define DP_DUAL_MODE_LSPCON_CURRENT_MODE 0x41
> >> +#define DP_DUAL_MODE_LSPCON_MODE_MASK 0x1
> >
> > Please indent the bit defnition by one space to make it stand out from
> > the reg defines a little.
> >
> Ok, the first two are registers only, I guess this is for
> DP_DUAL_MODE_LSPCON_MODE_MASK. I will align it.
> >> struct i2c_adapter;
> >>
> >> @@ -63,6 +67,20 @@ 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_invalid: No idea what's going on
> >> +* @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.
> >> +*/
> >> +enum drm_lspcon_mode {
> >> + DRM_LSPCON_MODE_INVALID,
> >> + DRM_LSPCON_MODE_LS,
> >> + DRM_LSPCON_MODE_PCON,
> >> +};
> >
> > If we change the _get_mode() thing to return the error status separately
> > from the mode, we won't need the INVALID value.
> >
> Agree.
> >> +
> >> +/**
> >> * 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 +88,7 @@ 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 +97,7 @@ 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 +109,13 @@ 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_dp_dual_mode_ioa_read(struct i2c_adapter *adapter, u8 *buffer,
> >> + u8 offset, u8 no_of_bytes);
> >> +int drm_dp_dual_mode_ioa_write(struct i2c_adapter *adapter, u8 *buffer,
> >> + u8 offset, u8 no_of_bytes);
> >> +int drm_dp_dual_mode_get_edid(void *data,
> >> + u8 *buf, unsigned int block, size_t len);
> >> +enum drm_lspcon_mode drm_lspcon_get_current_mode(struct i2c_adapter *adapter);
> >> +int drm_lspcon_change_mode(struct i2c_adapter *adapter,
> >> + enum drm_lspcon_mode reqd_mode);
> >> #endif
> >> --
> >> 1.9.1
> >
--
Ville Syrjälä
Intel OTC
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