[Intel-gfx] [PATCH v3 2/4] drm/i915: Add lspcon support for I915 driver

[Ville Syrjälä]

On Tue, Jul 05, 2016 at 06:35:48PM +0530, Shashank Sharma wrote:
> This patch adds a new file, to accommodate lspcon support
> for I915 driver. These functions probe, detect, initialize
> and configure an on-board lspcon device during the driver
> init time.
> 
> Also, this patch adds a small structure for lspcon device,
> which will provide the runtime status of the device.
> 
> V2: addressed ville's review comments
> - Clean the leftover macros from previous patch set
> 
> V3: Rebase
> 
> Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
> Signed-off-by: Akashdeep Sharma <akashdeep.sharma at intel.com>
> Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> ---
>  drivers/gpu/drm/i915/Makefile       |   1 +
>  drivers/gpu/drm/i915/intel_drv.h    |  13 +++-
>  drivers/gpu/drm/i915/intel_lspcon.c | 145 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 158 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/gpu/drm/i915/intel_lspcon.c
> 
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index 618293c..64cd373 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -95,6 +95,7 @@ i915-y += dvo_ch7017.o \
>  	  intel_dvo.o \
>  	  intel_hdmi.o \
>  	  intel_i2c.o \
> +	  intel_lspcon.o \
>  	  intel_lvds.o \
>  	  intel_panel.o \
>  	  intel_sdvo.o \
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index e6a24d2..e6982cf 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -922,12 +922,19 @@ struct intel_dp {
>  	bool compliance_test_active;
>  };
>  
> +struct intel_lspcon {
> +	bool active;
> +	enum drm_lspcon_mode mode_of_op;

I'd call this just 'mode'

> +	struct drm_dp_aux *aux;
> +};
> +
>  struct intel_digital_port {
>  	struct intel_encoder base;
>  	enum port port;
>  	u32 saved_port_bits;
>  	struct intel_dp dp;
>  	struct intel_hdmi hdmi;
> +	struct intel_lspcon lspcon;
>  	enum irqreturn (*hpd_pulse)(struct intel_digital_port *, bool);
>  	bool release_cl2_override;
>  	uint8_t max_lanes;
> @@ -1478,7 +1485,6 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
>  			       struct intel_crtc_state *pipe_config);
>  void intel_dp_dual_mode_set_tmds_output(struct intel_hdmi *hdmi, bool enable);
>  
> -
>  /* intel_lvds.c */
>  void intel_lvds_init(struct drm_device *dev);
>  struct intel_encoder *intel_get_lvds_encoder(struct drm_device *dev);
> @@ -1779,4 +1785,9 @@ int intel_color_check(struct drm_crtc *crtc, struct drm_crtc_state *state);
>  void intel_color_set_csc(struct drm_crtc_state *crtc_state);
>  void intel_color_load_luts(struct drm_crtc_state *crtc_state);
>  
> +/* intel_lspcon.c */
> +bool lspcon_init(struct intel_digital_port *intel_dig_port);
> +enum drm_connector_status
> +lspcon_ls_mode_detect(struct drm_connector *connector, bool force);
> +bool is_lspcon_active(struct intel_digital_port *dig_port);
>  #endif /* __INTEL_DRV_H__ */
> diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
> new file mode 100644
> index 0000000..fdeff71
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/intel_lspcon.c
> @@ -0,0 +1,145 @@
> +/*
> + * Copyright © 2016 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> + * DEALINGS IN THE SOFTWARE.
> + *
> + *
> + */
> +#include <drm/drm_edid.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_dp_dual_mode_helper.h>
> +#include "intel_drv.h"
> +
> +bool is_lspcon_active(struct intel_digital_port *dig_port)
> +{
> +	return dig_port->lspcon.active;
> +}

unused -> kill it

In fact the whole lspcon.active flags seems pretty pointless, so I'd
just kill that too.

> +
> +enum drm_lspcon_mode lspcon_get_current_mode(struct intel_lspcon *lspcon)
> +{
> +	enum drm_lspcon_mode current_mode = DRM_LSPCON_MODE_INVALID;
> +	struct i2c_adapter *adapter = &lspcon->aux->ddc;
> +
> +	if (drm_lspcon_get_mode(adapter, &current_mode))
> +		DRM_ERROR("Error reading LSPCON mode\n");
> +	else
> +		DRM_DEBUG_KMS("Current LSPCON mode %s\n",
> +			current_mode == DRM_LSPCON_MODE_PCON ? "PCON" : "LS");
> +	return current_mode;
> +}

I was going to suggest killing this one too, but I guess the debug
output might be useful. Make it static at least.

> +
> +int lspcon_change_mode(struct intel_lspcon *lspcon,
> +	enum drm_lspcon_mode mode, bool force)

static

> +{
> +	int err;
> +	enum drm_lspcon_mode current_mode;
> +	struct i2c_adapter *adapter = &lspcon->aux->ddc;
> +
> +	err = drm_lspcon_get_mode(adapter, &current_mode);
> +	if (err) {
> +		DRM_ERROR("Error reading LSPCON mode\n");
> +		return err;
> +	}
> +
> +	if (current_mode == mode && !force) {
> +		DRM_DEBUG_KMS("Current mode = desired LSPCON mode\n");
> +		return 0;
> +	}

We always call this with force==true, so it looks like a pointless
parameter. Also if force==true always, it doesn't necessary to even
query the current mode. Oh and I think we've already queried the mode
when this gets called.

> +
> +	err = drm_lspcon_set_mode(adapter, mode);
> +	if (err < 0) {
> +		DRM_ERROR("LSPCON mode change failed\n");
> +		return err;
> +	}
> +
> +	lspcon->mode_of_op = mode;
> +	DRM_DEBUG_KMS("LSPCON mode changed done\n");
> +	return 0;
> +}
> +
> +bool lspcon_detect_identifier(struct intel_lspcon *lspcon)

static

> +{
> +	enum drm_dp_dual_mode_type adaptor_type;
> +	struct i2c_adapter *adapter = &lspcon->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_LSPCON) {
> +		DRM_DEBUG_KMS("No LSPCON detected, found %s\n",
> +			drm_dp_get_dual_mode_type_name(adaptor_type));
> +		return false;
> +	}
> +
> +	/* Yay ... got a LSPCON device */
> +	DRM_DEBUG_KMS("LSPCON detected\n");
> +	return true;
> +}

This is small function and called only once, so I'd just inline it into
the caller actually.

> +
> +enum drm_lspcon_mode lspcon_probe(struct intel_lspcon *lspcon)

static

> +{
> +
> +	/* Detect a valid lspcon adaptor */
> +	if (!lspcon_detect_identifier(lspcon)) {
> +		DRM_DEBUG_KMS("No LSPCON identifier found\n");
> +		return false;
> +	}
> +
> +	/* Get LSPCON's mode of operation */
> +	lspcon->mode_of_op = lspcon_get_current_mode(lspcon);
> +	lspcon->active = true;
> +	return true;
> +}
> +
> +bool lspcon_init(struct intel_digital_port *intel_dig_port)
> +{
> +	struct intel_dp *dp = &intel_dig_port->dp;
> +	struct intel_lspcon *lspcon = &intel_dig_port->lspcon;
> +	struct drm_device *dev = intel_dig_port->base.base.dev;
> +
> +	if (!IS_GEN9(dev)) {
> +		DRM_ERROR("LSPCON is supported on GEN9 only\n");
> +		return false;
> +	}

Just remove this check? If it's not present, we won't detect it.

> +
> +	lspcon->active = false;
> +	lspcon->mode_of_op = DRM_LSPCON_MODE_INVALID;
> +	lspcon->aux = &dp->aux;
> +
> +	if (!lspcon_probe(lspcon)) {
> +		DRM_ERROR("Failed to probe lspcon\n");
> +		return false;
> +	}
> +
> +	/*
> +	* In the SW state machine, lets Put LSPCON in PCON mode only.
> +	* In this way, it will work with both HDMI 1.4 sinks as well as HDMI
> +	* 2.0 sinks.
> +	*/
> +	if (lspcon->active && lspcon->mode_of_op != DRM_LSPCON_MODE_PCON) {
> +		if (lspcon_change_mode(lspcon, DRM_LSPCON_MODE_PCON,
> +			true) < 0) {

indent fail.

> +			DRM_ERROR("LSPCON mode change to PCON failed\n");
> +			return false;
> +		}
> +	}
> +
> +	DRM_DEBUG_KMS("Success: LSPCON init\n");
> +	return true;
> +}
> -- 
> 1.9.1

-- 
Ville Syrjälä
Intel OTC