Re: [PATCH v2 2/4] drm/i915: Add lspcon support for I915 driver

Rodrigo Vivi
2016-06-30T22:30:24Z

On Tue, Jun 21, 2016 at 8:00 AM, Shashank Sharma
<shashank.sharma@intel.com> 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
>
> Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
> Signed-off-by: Akashdeep Sharma <akashdeep.sharma@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 276abf1..d40ff7d 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -93,6 +93,7 @@ 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 7d0e071..4e49c16 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -894,12 +894,19 @@ struct intel_dp {
> bool compliance_test_active;
> };
>
> +struct intel_lspcon {
> + bool active;
> + enum drm_lspcon_mode mode_of_op;
> + 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;
> @@ -1450,7 +1457,6 @@ 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);
> bool intel_is_dual_link_lvds(struct drm_device *dev);
> @@ -1745,4 +1751,9 @@ 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"
> +

Does this new file worth/deserves/needs a Docbook?

> +bool is_lspcon_active(struct intel_digital_port *dig_port)
> +{
> + return dig_port->lspcon.active;
> +}
> +
> +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;
> +}
> +
> +int lspcon_change_mode(struct intel_lspcon *lspcon,
> + enum drm_lspcon_mode mode, bool force)
> +{
> + 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");\

debug or error?
maybe print the desired mode here?

in case desired mode is useless to know and if it happens with
frequency I'd believe we could skip the debug message and just move
on...

> + return 0;
> + }
> +
> + 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)
> +{
> + 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) {

shouldn't we do TYPE2 | bit3 here?

> + 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;
> +}
> +
> +enum drm_lspcon_mode lspcon_probe(struct intel_lspcon *lspcon)
> +{
> +
> + /* 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;
> + }
> +
> + 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.
> + */

Reading the specs seems to me that for HDMI 1.4 the LS is the
recommended and for HDMI 2.0 the PCON is required... but I believe we
don't have a way to determine that right?

> + if (lspcon->active && lspcon->mode_of_op != DRM_LSPCON_MODE_PCON) {
> + if (lspcon_change_mode(lspcon, DRM_LSPCON_MODE_PCON,
> + true) < 0) {
> + DRM_ERROR("LSPCON mode change to PCON failed\n");
> + return false;
> + }
> + }
> +
> + DRM_DEBUG_KMS("Success: LSPCON init\n");
> + return true;
> +}
> --
> 1.9.1
>
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--
Rodrigo Vivi
Blog: http://blog.vivi.eng.br