[RFC PATCH 5/6] drm/i915: Implement HDCP for HDMI

Sean Paul
2017-11-30T03:10:18Z

This patch adds HDCP support for HDMI connectors by implementing
the intel_hdcp_shim.

Nothing too special, just a bunch of DDC reads/writes.

Signed-off-by: Sean Paul <seanpaul@chromium.org>
---
drivers/gpu/drm/i915/i915_reg.h | 1 +
drivers/gpu/drm/i915/intel_ddi.c | 50 ++++++++
drivers/gpu/drm/i915/intel_hdmi.c | 253 ++++++++++++++++++++++++++++++++++++++
3 files changed, 304 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 78370877fea3..061c52a5d7d7 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -8400,6 +8400,7 @@ enum skl_power_gate {
#define TRANS_DDI_EDP_INPUT_A_ONOFF (4<<12)
#define TRANS_DDI_EDP_INPUT_B_ONOFF (5<<12)
#define TRANS_DDI_EDP_INPUT_C_ONOFF (6<<12)
+#define TRANS_DDI_HDCP_SIGNALLING (1<<9)
#define TRANS_DDI_DP_VC_PAYLOAD_ALLOC (1<<8)
#define TRANS_DDI_HDMI_SCRAMBLER_CTS_ENABLE (1<<7)
#define TRANS_DDI_HDMI_SCRAMBLER_RESET_FREQ (1<<6)
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 0e69337f410d..0324b09ecf76 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1650,6 +1650,56 @@ void intel_ddi_disable_transcoder_func(struct drm_i915_private *dev_priv,
I915_WRITE(reg, val);
}

+int intel_ddi_disable_hdcp_signalling(struct intel_encoder *intel_encoder)
+{
+ struct drm_device *dev = intel_encoder->base.dev;
+ struct drm_i915_private *dev_priv = to_i915(dev);
+ enum pipe pipe = 0;
+ int ret = 0;
+ uint32_t tmp;
+
+ if (!intel_display_power_get_if_enabled(dev_priv,
+ intel_encoder->power_domain))
+ return -ENXIO;
+
+ if (!intel_encoder->get_hw_state(intel_encoder, &pipe)) {
+ ret = -EIO;
+ goto out;
+ }
+
+ tmp = I915_READ(TRANS_DDI_FUNC_CTL(pipe));
+ tmp &= ~TRANS_DDI_HDCP_SIGNALLING;
+ I915_WRITE(TRANS_DDI_FUNC_CTL(pipe), tmp);
+out:
+ intel_display_power_put(dev_priv, intel_encoder->power_domain);
+ return ret;
+}
+
+int intel_ddi_enable_hdcp_signalling(struct intel_encoder *intel_encoder)
+{
+ struct drm_device *dev = intel_encoder->base.dev;
+ struct drm_i915_private *dev_priv = to_i915(dev);
+ enum pipe pipe = 0;
+ int ret = 0;
+ uint32_t tmp;
+
+ if (!intel_display_power_get_if_enabled(dev_priv,
+ intel_encoder->power_domain))
+ return -ENXIO;
+
+ if (!intel_encoder->get_hw_state(intel_encoder, &pipe)) {
+ ret = -EIO;
+ goto out;
+ }
+
+ tmp = I915_READ(TRANS_DDI_FUNC_CTL(pipe));
+ tmp |= TRANS_DDI_HDCP_SIGNALLING;
+ I915_WRITE(TRANS_DDI_FUNC_CTL(pipe), tmp);
+out:
+ intel_display_power_put(dev_priv, intel_encoder->power_domain);
+ return ret;
+}
+
bool intel_ddi_connector_get_hw_state(struct intel_connector *intel_connector)
{
struct drm_device *dev = intel_connector->base.dev;
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 59247a49a077..563168897dd9 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -34,6 +34,7 @@
#include <drm/drm_atomic_helper.h>
#include <drm/drm_crtc.h>
#include <drm/drm_edid.h>
+#include <drm/drm_hdcp.h>
#include <drm/drm_scdc_helper.h>
#include "intel_drv.h"
#include <drm/i915_drm.h>
@@ -875,6 +876,252 @@ void intel_dp_dual_mode_set_tmds_output(struct intel_hdmi *hdmi, bool enable)
adapter, enable);
}

+static int intel_hdmi_hdcp_read(struct intel_digital_port *intel_dig_port,
+ unsigned int offset, void *buffer, size_t size)
+{
+ struct intel_hdmi *hdmi = &intel_dig_port->hdmi;
+ struct drm_i915_private *dev_priv =
+ intel_dig_port->base.base.dev->dev_private;
+ struct i2c_adapter *adapter = intel_gmbus_get_adapter(dev_priv,
+ hdmi->ddc_bus);
+ int ret;
+ u8 start = offset & 0xff;
+ struct i2c_msg msgs[] = {
+ {
+ .addr = DRM_HDCP_DDC_ADDR,
+ .flags = 0,
+ .len = 1,
+ .buf = &start,
+ },
+ {
+ .addr = DRM_HDCP_DDC_ADDR,
+ .flags = I2C_M_RD,
+ .len = size,
+ .buf = buffer
+ }
+ };
+ ret = i2c_transfer(adapter, msgs, ARRAY_SIZE(msgs));
+ if (ret == ARRAY_SIZE(msgs))
+ return 0;
+ return ret >= 0 ? -EIO : ret;
+}
+
+static int intel_hdmi_hdcp_write(struct intel_digital_port *intel_dig_port,
+ unsigned int offset, void *buffer, size_t size)
+{
+ struct intel_hdmi *hdmi = &intel_dig_port->hdmi;
+ struct drm_i915_private *dev_priv =
+ intel_dig_port->base.base.dev->dev_private;
+ struct i2c_adapter *adapter = intel_gmbus_get_adapter(dev_priv,
+ hdmi->ddc_bus);
+ int ret;
+ u8 *write_buf;
+ struct i2c_msg msg;
+
+ write_buf = kzalloc(size + 1, GFP_KERNEL);
+ if (!write_buf)
+ return -ENOMEM;
+
+ write_buf[0] = offset & 0xff;
+ memcpy(&write_buf[1], buffer, size);
+
+ msg.addr = DRM_HDCP_DDC_ADDR;
+ msg.flags = 0,
+ msg.len = size + 1,
+ msg.buf = write_buf;
+
+ ret = i2c_transfer(adapter, &msg, 1);
+ if (ret == 1)
+ return 0;
+ return ret >= 0 ? -EIO : ret;
+}
+
+static
+int intel_hdmi_hdcp_write_an_aksv(struct intel_digital_port *intel_dig_port,
+ u8 *an)
+{
+ struct intel_hdmi *hdmi = &intel_dig_port->hdmi;
+ struct drm_i915_private *dev_priv =
+ intel_dig_port->base.base.dev->dev_private;
+ struct i2c_adapter *adapter = intel_gmbus_get_adapter(dev_priv,
+ hdmi->ddc_bus);
+ int ret;
+
+ ret = intel_hdmi_hdcp_write(intel_dig_port, DRM_HDCP_DDC_AN, an,
+ DRM_HDCP_AN_LEN);
+ if (ret) {
+ DRM_ERROR("Write An over DDC failed (%d)\n", ret);
+ return ret;
+ }
+
+ ret = intel_gmbus_output_aksv(adapter);
+ if (ret < 0) {
+ DRM_ERROR("Failed to output aksv (%d)\n", ret);
+ return ret;
+ }
+ return 0;
+}
+
+static int intel_hdmi_hdcp_read_bksv(struct intel_digital_port *intel_dig_port,
+ u8 *bksv)
+{
+ int ret;
+ ret = intel_hdmi_hdcp_read(intel_dig_port, DRM_HDCP_DDC_BKSV, bksv,
+ DRM_HDCP_KSV_LEN);
+ if (ret)
+ DRM_ERROR("Read Bksv over DDC failed (%d)\n", ret);
+ return ret;
+}
+
+static
+int intel_hdmi_hdcp_read_bstatus(struct intel_digital_port *intel_dig_port,
+ u8 *bstatus)
+{
+ int ret;
+ ret = intel_hdmi_hdcp_read(intel_dig_port, DRM_HDCP_DDC_BSTATUS,
+ bstatus, DRM_HDCP_BSTATUS_LEN);
+ if (ret)
+ DRM_ERROR("Read bstatus over DDC failed (%d)\n", ret);
+ return ret;
+}
+
+static
+int intel_hdmi_hdcp_repeater_present(struct intel_digital_port *intel_dig_port,
+ bool *repeater_present)
+{
+ int ret;
+ u8 val;
+
+ ret = intel_hdmi_hdcp_read(intel_dig_port, DRM_HDCP_DDC_BCAPS, &val, 1);
+ if (ret) {
+ DRM_ERROR("Read bcaps over DDC failed (%d)\n", ret);
+ return ret;
+ }
+ *repeater_present = val & DRM_HDCP_DDC_BCAPS_REPEATER_PRESENT;
+ return 0;
+}
+
+static
+int intel_hdmi_hdcp_read_ri_prime(struct intel_digital_port *intel_dig_port,
+ u8 *ri_prime)
+{
+ int ret;
+ ret = intel_hdmi_hdcp_read(intel_dig_port, DRM_HDCP_DDC_RI_PRIME,
+ ri_prime, DRM_HDCP_RI_LEN);
+ if (ret)
+ DRM_ERROR("Read Ri' over DDC failed (%d)\n", ret);
+ return ret;
+}
+
+static
+int intel_hdmi_hdcp_read_ksv_ready(struct intel_digital_port *intel_dig_port,
+ bool *ksv_ready)
+{
+ int ret;
+ u8 val;
+
+ ret = intel_hdmi_hdcp_read(intel_dig_port, DRM_HDCP_DDC_BCAPS, &val, 1);
+ if (ret) {
+ DRM_ERROR("Read bcaps over DDC failed (%d)\n", ret);
+ return ret;
+ }
+ *ksv_ready = val & DRM_HDCP_DDC_BCAPS_KSV_FIFO_READY;
+ return 0;
+}
+
+static
+int intel_hdmi_hdcp_read_ksv_fifo(struct intel_digital_port *intel_dig_port,
+ int num_downstream, u8 *ksv_fifo)
+{
+ int ret;
+ ret = intel_hdmi_hdcp_read(intel_dig_port, DRM_HDCP_DDC_KSV_FIFO,
+ ksv_fifo, num_downstream * DRM_HDCP_KSV_LEN);
+ if (ret) {
+ DRM_ERROR("Read ksv fifo over DDC failed (%d)\n", ret);
+ return ret;
+ }
+ return 0;
+}
+
+static
+int intel_hdmi_hdcp_read_v_prime_part(struct intel_digital_port *intel_dig_port,
+ int i, u32 *part)
+{
+ int ret;
+
+ if (i >= DRM_HDCP_V_PRIME_NUM_PARTS)
+ return -EINVAL;
+
+ ret = intel_hdmi_hdcp_read(intel_dig_port, DRM_HDCP_DDC_V_PRIME(i),
+ part, DRM_HDCP_V_PRIME_PART_LEN);
+ if (ret)
+ DRM_ERROR("Read V'[%d] over DDC failed (%d)\n", i, ret);
+ return ret;
+}
+
+static
+int intel_hdmi_hdcp_toggle_signalling(struct intel_digital_port *intel_dig_port,
+ bool enable)
+{
+ int ret;
+ if (enable) {
+ ret = intel_ddi_enable_hdcp_signalling(&intel_dig_port->base);
+ if (ret) {
+ DRM_ERROR("Enable HDCP signalling failed (%d)\n", ret);
+ return ret;
+ }
+ } else {
+ usleep_range(6, 60); /* Bspec says >= 6us */
+ ret = intel_ddi_disable_hdcp_signalling(&intel_dig_port->base);
+ if (ret) {
+ DRM_ERROR("Enable HDCP signalling failed (%d)\n", ret);
+ return ret;
+ }
+ }
+ return 0;
+}
+
+static
+bool intel_hdmi_hdcp_check_link(struct intel_digital_port *intel_dig_port)
+{
+ struct drm_i915_private *dev_priv =
+ intel_dig_port->base.base.dev->dev_private;
+ enum port port = intel_dig_port->port;
+ int ret;
+ union {
+ u32 reg;
+ u8 shim[DRM_HDCP_RI_LEN];
+ } ri;
+
+ ret = intel_hdmi_hdcp_read_ri_prime(intel_dig_port, ri.shim);
+ if (ret)
+ return false;
+
+ I915_WRITE(SKL_PORT_HDCP_RPRIME(port), ri.reg);
+
+ // Wait for Ri prime match
+ if (wait_for(I915_READ(SKL_PORT_HDCP_STATUS(port)) &
+ (SKL_HDCP_STATUS_RI_MATCH | SKL_HDCP_STATUS_ENC), 1)) {
+ DRM_ERROR("Ri' mismatch detected, link check failed (%x)\n",
+ I915_READ(SKL_PORT_HDCP_STATUS(port)));
+ return false;
+ }
+ return true;
+}
+
+static const struct intel_hdcp_shim intel_hdmi_hdcp_shim = {
+ .write_an_aksv = intel_hdmi_hdcp_write_an_aksv,
+ .read_bksv = intel_hdmi_hdcp_read_bksv,
+ .read_bstatus = intel_hdmi_hdcp_read_bstatus,
+ .repeater_present = intel_hdmi_hdcp_repeater_present,
+ .read_ri_prime = intel_hdmi_hdcp_read_ri_prime,
+ .read_ksv_ready = intel_hdmi_hdcp_read_ksv_ready,
+ .read_ksv_fifo = intel_hdmi_hdcp_read_ksv_fifo,
+ .read_v_prime_part = intel_hdmi_hdcp_read_v_prime_part,
+ .toggle_signalling = intel_hdmi_hdcp_toggle_signalling,
+ .check_link = intel_hdmi_hdcp_check_link,
+};
+
static void intel_hdmi_prepare(struct intel_encoder *encoder,
const struct intel_crtc_state *crtc_state)
{
@@ -2039,6 +2286,12 @@ void intel_hdmi_init_connector(struct intel_digital_port *intel_dig_port,

intel_hdmi_add_properties(intel_hdmi, connector);

+ if (INTEL_GEN(dev_priv) >= 9) {
+ drm_connector_attach_content_protection_property(connector);
+ intel_connector->hdcp_shim = &intel_hdmi_hdcp_shim;
+ INIT_DELAYED_WORK(&intel_connector->hdcp_work, intel_hdcp_work);
+ }
+
intel_connector_attach_encoder(intel_connector, intel_encoder);
intel_hdmi->attached_connector = intel_connector;

--
2.15.0.531.g2ccb3012c9-goog