drm/i915: Add lspcon support for I915 driver

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
V4: addressed ville's review comments
- make internal functions static
- remove lspcon_detect_identifier, make it inline with lspcon_probe
- remove is_lspcon_active function
- remove force check while setting a lspcon mode

V5: Rebase
V6: Pass dev_priv to IS_GEN9 check

Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Akashdeep Sharma <akashdeep.sharma@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476455212-27893-3-git-send-email-shashank.sharma@intel.com

1 files changed, 128 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
new file mode 100644
index 000000000000..628ae6fbdcb1
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_lspcon.c
@@ -0,0 +1,128 @@
+/*
+ * 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"
+
+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;
+}
+
+static 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) {
+                DRM_DEBUG_KMS("Current mode = desired LSPCON mode\n");
+                return 0;
+        }
+
+        err = drm_lspcon_set_mode(adapter, mode);
+        if (err < 0) {
+                DRM_ERROR("LSPCON mode change failed\n");
+                return err;
+        }
+
+        lspcon->mode = mode;
+        DRM_DEBUG_KMS("LSPCON mode changed done\n");
+        return 0;
+}
+
+static bool lspcon_probe(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) {
+                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");
+        lspcon->mode = 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;
+        struct drm_i915_private *dev_priv = to_i915(dev);
+
+        if (!IS_GEN9(dev_priv)) {
+                DRM_ERROR("LSPCON is supported on GEN9 only\n");
+                return false;
+        }
+
+        lspcon->active = false;
+        lspcon->mode = 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 != 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;
+}