[Intel-gfx] [PATCH 10/12] drm/i915: Add lspcon core functions
Sharma, Shashank
shashank.sharma at intel.com
Tue May 3 16:14:43 UTC 2016
On 5/3/2016 9:39 PM, Ville Syrjälä wrote:
> On Tue, May 03, 2016 at 09:18:49PM +0530, Sharma, Shashank wrote:
>> Regards
>> Shashank
>>
>> On 5/2/2016 7:21 PM, Ville Syrjälä wrote:
>>> On Mon, Apr 04, 2016 at 05:31:46PM +0530, Shashank Sharma wrote:
>>>> This patch adds lspcon's internal functions, which work
>>>> on the probe layer, and indicate the working status of
>>>> lspcon, which are mostly:
>>>>
>>>> probe: A lspcon device is probed only once, during boot
>>>> time, as its always present with the device, next to port.
>>>> So the i2c_over_aux channel is alwyas read/writeable if DC is
>>>> powered on. If VBT says that this port contains lspcon, we
>>>> check and probe the HW to verify and initialize it.
>>>>
>>>> get_mode: This function indicates the current mode of operation
>>>> of lspcon (ls or pcon mode)
>>>>
>>>> change_mode: This function can change the lspcon's mode of
>>>> operation to desired mode.
>>>>
>>>> Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
>>>> Signed-off-by: Akashdeep Sharma <Akashdeep.sharma at intel.com>
>>>> ---
>>>> drivers/gpu/drm/i915/intel_lspcon.c | 145 ++++++++++++++++++++++++++++++++++++
>>>> 1 file changed, 145 insertions(+)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
>>>> index c3c1cd2..617fe3f 100644
>>>> --- a/drivers/gpu/drm/i915/intel_lspcon.c
>>>> +++ b/drivers/gpu/drm/i915/intel_lspcon.c
>>>> @@ -61,6 +61,144 @@ static struct intel_lspcon
>>>> return enc_to_lspcon(&intel_attached_encoder(connector)->base);
>>>> }
>>>>
>>>> +enum lspcon_mode lspcon_get_current_mode(struct intel_lspcon *lspcon)
>>>> +{
>>>> + u8 data;
>>>> + int err = 0;
>>>> + struct intel_digital_port *dig_port = lspcon_to_dig_port(lspcon);
>>>> + struct i2c_adapter *adapter = &dig_port->dp.aux.ddc;
>>>> +
>>>> + /* Read Status: i2c over aux */
>>>> + err = drm_dp_dual_mode_ioa_read(adapter, &data,
>>>> + LSPCON_MODE_CHECK_OFFSET, sizeof(data));
>>>> + if (err < 0) {
>>>> + DRM_ERROR("LSPCON read mode ioa (0x80, 0x41) failed\n");
>>>> + return lspcon_mode_invalid;
>>>> + }
>>>> +
>>>> + DRM_DEBUG_DRIVER("LSPCON mode (0x80, 0x41) = %x\n", (unsigned int)data);
>>>> + return data & LSPCON_MODE_MASK ? lspcon_mode_pcon : lspcon_mode_ls;
>>>> +}
>>>> +
>>>> +int lspcon_change_mode(struct intel_lspcon *lspcon,
>>>> + enum lspcon_mode mode, bool force)
>>>> +{
>>>> + u8 data;
>>>> + int err;
>>>> + int time_out = 200;
>>>> + enum lspcon_mode current_mode;
>>>> + struct intel_digital_port *dig_port = lspcon_to_dig_port(lspcon);
>>>> +
>>>> + current_mode = lspcon_get_current_mode(lspcon);
>>>> + if (current_mode == lspcon_mode_invalid) {
>>>> + DRM_ERROR("Failed to get current LSPCON mode\n");
>>>> + return -EFAULT;
>>>> + }
>>>> +
>>>> + if (current_mode == mode && !force) {
>>>> + DRM_DEBUG_DRIVER("Current mode = desired LSPCON mode\n");
>>>> + return 0;
>>>> + }
>>>> +
>>>> + if (mode == lspcon_mode_ls)
>>>> + data = ~LSPCON_MODE_MASK;
>>>> + else
>>>> + data = LSPCON_MODE_MASK;
>>>> +
>>>> + /* Change mode */
>>>> + err = drm_dp_dual_mode_ioa_write(&dig_port->dp.aux.ddc, &data,
>>>> + LSPCON_MODE_CHANGE_OFFSET, 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.
>>>> + */
>>>> + while (time_out) {
>>>> + current_mode = lspcon_get_current_mode(lspcon);
>>>> + if (current_mode != mode) {
>>>> + mdelay(10);
>>>> + time_out -= 10;
>>>> + } else {
>>>> + lspcon->mode_of_op = mode;
>>>> + DRM_DEBUG_DRIVER("LSPCON mode changed to %s\n",
>>>> + mode == lspcon_mode_ls ? "LS" : "PCON");
>>>> + return 0;
>>>> + }
>>>> + }
>>>> +
>>>> + DRM_ERROR("LSPCON mode change timed out\n");
>>>> + return -EFAULT;
>>>> +}
>>>
>>> I think we probably want to put most of this stuff into the helper. We
>>> already have the LSPCON identification there, so having a few helpers
>>> to set/get the ls vs. pconn mode would seem appropriate.
>>>
>> Actually handling of LS/PCON modes are specific to MCA chips, and some
>> of the mode change mechanism and few other control stuff may not be same
>> on parade or some other vendor's chip, so I am not sure if we should
>> create a helper for something which is specific to this chip. You
>> suggest so ?
>
> Well, if we already put the detection into the helper we already have
> some vendor specific stuff there, no? Or would the other vendor's chips
> be identifiable in the same way?
>
> Anyways, I presume someone else than Intel might want to use these same
> chips in their products, so having the support in a central place would
> seem like a good idea. If we start to see incompatble LSPCON chips from
> multiple vendors we'll need to rethink how we support them all, but
> until we know how exactly they differ it's rather impossible to design
> the helper to deal with them. So as a first step I'd stuff it all into
> the helper.
>
Yes, makes more sense this way. I will try to go through parade specs
once, and see if I can find something which needs immediate discussion
here. Else, I will move this into the central layer.
>>>> +
>>>> +bool lspcon_detect_identifier(struct intel_lspcon *lspcon)
>>>> +{
>>>> + enum drm_dp_dual_mode_type adaptor_type;
>>>> + struct intel_digital_port *dig_port = lspcon_to_dig_port(lspcon);
>>>> + struct i2c_adapter *adapter = &dig_port->dp.aux.ddc;
>>>> +
>>>> + /* Lets probe the adaptor and check its type */
>>>> + adaptor_type = drm_dp_dual_mode_detect(adapter);
>>>> + if (adaptor_type != DRM_DP_DUAL_MODE_TYPE2_LSPCON) {
>>>> + DRM_DEBUG_DRIVER("No LSPCON detected, found %s\n",
>>>> + drm_dp_get_dual_mode_type_name(adaptor_type));
>>>> + return false;
>>>> + }
>>>> +
>>>> + /* Yay ... got a LSPCON device */
>>>> + DRM_DEBUG_DRIVER("LSPCON detected\n");
>>>> + return true;
>>>> +}
>>>> +
>>>> +enum lspcon_mode lspcon_probe(struct intel_lspcon *lspcon)
>>>> +{
>>>> + enum lspcon_mode current_mode;
>>>> +
>>>> + /* Detect a valid lspcon */
>>>> + if (!lspcon_detect_identifier(lspcon)) {
>>>> + DRM_DEBUG_DRIVER("Failed to find LSPCON identifier\n");
>>>> + return false;
>>>> + }
>>>> +
>>>> + /* LSPCON's mode of operation */
>>>> + current_mode = lspcon_get_current_mode(lspcon);
>>>> + if (current_mode == lspcon_mode_invalid) {
>>>> + DRM_ERROR("Failed to read LSPCON mode\n");
>>>> + return false;
>>>> + }
>>>> +
>>>> + /* All is well */
>>>> + lspcon->mode_of_op = current_mode;
>>>> + lspcon->active = true;
>>>> + return current_mode;
>>>> +}
>>>> +
>>>> +bool lspcon_device_init(struct intel_lspcon *lspcon)
>>>> +{
>>>> +
>>>> + /* Lets check LSPCON now, probe the HW status */
>>>> + lspcon->active = false;
>>>> + lspcon->mode_of_op = lspcon_mode_invalid;
>>>> + if (!lspcon_probe(lspcon)) {
>>>> + DRM_ERROR("Failed to probe lspcon");
>>>> + return false;
>>>> + }
>>>> +
>>>> + /* We wish to keep LSPCON in LS mode */
>>>> + if (lspcon->active && lspcon->mode_of_op != lspcon_mode_ls) {
>>>> + if (lspcon_change_mode(lspcon, lspcon_mode_ls, true) < 0) {
>>>> + DRM_ERROR("LSPCON mode change to LS failed\n");
>>>> + return false;
>>>> + }
>>>> + }
>>>> + DRM_DEBUG_DRIVER("LSPCON init success\n");
>>>> + return true;
>>>> +}
>>>> +
>>>> struct edid *lspcon_get_edid(struct intel_lspcon *lspcon, struct drm_connector
>>>> *connector)
>>>> {
>>>> @@ -233,6 +371,7 @@ int intel_lspcon_init_connector(struct intel_digital_port *intel_dig_port)
>>>> struct intel_encoder *intel_encoder = &intel_dig_port->base;
>>>> struct drm_device *dev = intel_encoder->base.dev;
>>>> struct drm_i915_private *dev_priv = dev->dev_private;
>>>> + struct intel_lspcon *lspcon = &intel_dig_port->lspcon;
>>>> struct intel_connector *intel_connector;
>>>> struct drm_connector *connector;
>>>> enum port port = intel_dig_port->port;
>>>> @@ -314,6 +453,12 @@ int intel_lspcon_init_connector(struct intel_digital_port *intel_dig_port)
>>>> I915_WRITE(PEG_BAND_GAP_DATA, (temp & ~0xf) | 0xd);
>>>> }
>>>>
>>>> + /* Now initialize the LSPCON device */
>>>> + if (!lspcon_device_init(lspcon)) {
>>>> + DRM_ERROR("LSPCON device init failed\n");
>>>> + goto fail;
>>>> + }
>>>> +
>>>> DRM_DEBUG_DRIVER("Success: LSPCON connector init\n");
>>>> return 0;
>>>>
>>>> --
>>>> 1.9.1
>>>
>
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