--- /dev/null
+/*
+ * 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 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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 <linux/errno.h>
+#include <linux/export.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <drm/drm_dp_dual_mode_helper.h>
+#include <drm/drmP.h>
+
+/**
+ * DOC: dp dual mode helpers
+ *
+ * Helper functions to deal with DP dual mode (aka. DP++) adaptors.
+ *
+ * Type 1:
+ * Adaptor registers (if any) and the sink DDC bus may be accessed via I2C.
+ *
+ * Type 2:
+ * Adaptor registers and sink DDC bus can be accessed either via I2C or
+ * I2C-over-AUX. Source devices may choose to implement either of these
+ * access methods.
+ */
+
+#define DP_DUAL_MODE_SLAVE_ADDRESS 0x40
+
+/**
+ * drm_dp_dual_mode_read - Read from the DP dual mode adaptor register(s)
+ * @adapter: I2C adapter for the DDC bus
+ * @offset: register offset
+ * @buffer: buffer for return data
+ * @size: sizo of the buffer
+ *
+ * Reads @size bytes from the DP dual mode adaptor registers
+ * starting at @offset.
+ *
+ * Returns:
+ * 0 on success, negative error code on failure
+ */
+ssize_t drm_dp_dual_mode_read(struct i2c_adapter *adapter,
+ u8 offset, void *buffer, size_t size)
+{
+ struct i2c_msg msgs[] = {
+ {
+ .addr = DP_DUAL_MODE_SLAVE_ADDRESS,
+ .flags = 0,
+ .len = 1,
+ .buf = &offset,
+ },
+ {
+ .addr = DP_DUAL_MODE_SLAVE_ADDRESS,
+ .flags = I2C_M_RD,
+ .len = size,
+ .buf = buffer,
+ },
+ };
+ int ret;
+
+ ret = i2c_transfer(adapter, msgs, ARRAY_SIZE(msgs));
+ if (ret < 0)
+ return ret;
+ if (ret != ARRAY_SIZE(msgs))
+ return -EPROTO;
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_dp_dual_mode_read);
+
+/**
+ * drm_dp_dual_mode_write - Write to the DP dual mode adaptor register(s)
+ * @adapter: I2C adapter for the DDC bus
+ * @offset: register offset
+ * @buffer: buffer for write data
+ * @size: sizo of the buffer
+ *
+ * Writes @size bytes to the DP dual mode adaptor registers
+ * starting at @offset.
+ *
+ * Returns:
+ * 0 on success, negative error code on failure
+ */
+ssize_t drm_dp_dual_mode_write(struct i2c_adapter *adapter,
+ u8 offset, const void *buffer, size_t size)
+{
+ struct i2c_msg msg = {
+ .addr = DP_DUAL_MODE_SLAVE_ADDRESS,
+ .flags = 0,
+ .len = 1 + size,
+ .buf = NULL,
+ };
+ void *data;
+ int ret;
+
+ data = kmalloc(msg.len, GFP_TEMPORARY);
+ if (!data)
+ return -ENOMEM;
+
+ msg.buf = data;
+
+ memcpy(data, &offset, 1);
+ memcpy(data + 1, buffer, size);
+
+ ret = i2c_transfer(adapter, &msg, 1);
+
+ kfree(data);
+
+ if (ret < 0)
+ return ret;
+ if (ret != 1)
+ return -EPROTO;
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_dp_dual_mode_write);
+
+static bool is_hdmi_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN])
+{
+ static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN] =
+ "DP-HDMI ADAPTOR\x04";
+
+ return memcmp(hdmi_id, dp_dual_mode_hdmi_id,
+ sizeof(dp_dual_mode_hdmi_id)) == 0;
+}
+
+static bool is_type2_adaptor(uint8_t adaptor_id)
+{
+ return adaptor_id == (DP_DUAL_MODE_TYPE_TYPE2 |
+ DP_DUAL_MODE_REV_TYPE2);
+}
+
+/**
+ * drm_dp_dual_mode_detect - Identify the DP dual mode adaptor
+ * @adapter: I2C adapter for the DDC bus
+ *
+ * Attempt to identify the type of the DP dual mode adaptor used.
+ *
+ * Note that when the answer is @DRM_DP_DUAL_MODE_UNKNOWN it's not
+ * certain whether we're dealing with a native HDMI port or
+ * a type 1 DVI dual mode adaptor. The driver will have to use
+ * some other hardware/driver specific mechanism to make that
+ * distinction.
+ *
+ * Returns:
+ * The type of the DP dual mode adaptor used
+ */
+enum drm_dp_dual_mode_type drm_dp_dual_mode_detect(struct i2c_adapter *adapter)
+{
+ char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN] = {};
+ uint8_t adaptor_id = 0x00;
+ ssize_t ret;
+
+ /*
+ * Let's see if the adaptor is there the by reading the
+ * HDMI ID registers.
+ *
+ * Note that type 1 DVI adaptors are not required to implemnt
+ * any registers, and that presents a problem for detection.
+ * If the i2c transfer is nacked, we may or may not be dealing
+ * with a type 1 DVI adaptor. Some other mechanism of detecting
+ * the presence of the adaptor is required. One way would be
+ * to check the state of the CONFIG1 pin, Another method would
+ * simply require the driver to know whether the port is a DP++
+ * port or a native HDMI port. Both of these methods are entirely
+ * hardware/driver specific so we can't deal with them here.
+ */
+ ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_HDMI_ID,
+ hdmi_id, sizeof(hdmi_id));
+ if (ret)
+ return DRM_DP_DUAL_MODE_UNKNOWN;
+
+ /*
+ * Sigh. Some (maybe all?) type 1 adaptors are broken and ack
+ * the offset but ignore it, and instead they just always return
+ * data from the start of the HDMI ID buffer. So for a broken
+ * type 1 HDMI adaptor a single byte read will always give us
+ * 0x44, and for a type 1 DVI adaptor it should give 0x00
+ * (assuming it implements any registers). Fortunately neither
+ * of those values will match the type 2 signature of the
+ * DP_DUAL_MODE_ADAPTOR_ID register so we can proceed with
+ * the type 2 adaptor detection safely even in the presence
+ * of broken type 1 adaptors.
+ */
+ ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_ADAPTOR_ID,
+ &adaptor_id, sizeof(adaptor_id));
+ if (ret == 0) {
+ if (is_type2_adaptor(adaptor_id)) {
+ if (is_hdmi_adaptor(hdmi_id))
+ return DRM_DP_DUAL_MODE_TYPE2_HDMI;
+ else
+ return DRM_DP_DUAL_MODE_TYPE2_DVI;
+ }
+ }
+
+ if (is_hdmi_adaptor(hdmi_id))
+ return DRM_DP_DUAL_MODE_TYPE1_HDMI;
+ else
+ return DRM_DP_DUAL_MODE_TYPE1_DVI;
+}
+EXPORT_SYMBOL(drm_dp_dual_mode_detect);
+
+/**
+ * drm_dp_dual_mode_max_tmds_clock - Max TMDS clock for DP dual mode adaptor
+ * @type: DP dual mode adaptor type
+ * @adapter: I2C adapter for the DDC bus
+ *
+ * Determine the max TMDS clock the adaptor supports based on the
+ * type of the dual mode adaptor and the DP_DUAL_MODE_MAX_TMDS_CLOCK
+ * register (on type2 adaptors). As some type 1 adaptors have
+ * problems with registers (see comments in drm_dp_dual_mode_detect())
+ * we don't read the register on those, instead we simply assume
+ * a 165 MHz limit based on the specification.
+ *
+ * Returns:
+ * Maximum supported TMDS clock rate for the DP dual mode adaptor in kHz.
+ */
+int drm_dp_dual_mode_max_tmds_clock(enum drm_dp_dual_mode_type type,
+ struct i2c_adapter *adapter)
+{
+ uint8_t max_tmds_clock;
+ ssize_t ret;
+
+ /* native HDMI so no limit */
+ if (type == DRM_DP_DUAL_MODE_NONE)
+ return 0;
+
+ /*
+ * Type 1 adaptors are limited to 165MHz
+ * Type 2 adaptors can tells us their limit
+ */
+ if (type < DRM_DP_DUAL_MODE_TYPE2_DVI)
+ return 165000;
+
+ ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_MAX_TMDS_CLOCK,
+ &max_tmds_clock, sizeof(max_tmds_clock));
+ if (ret || max_tmds_clock == 0x00 || max_tmds_clock == 0xff) {
+ DRM_DEBUG_KMS("Failed to query max TMDS clock\n");
+ return 165000;
+ }
+
+ return max_tmds_clock * 5000 / 2;
+}
+EXPORT_SYMBOL(drm_dp_dual_mode_max_tmds_clock);
+
+/**
+ * drm_dp_dual_mode_get_tmds_output - Get the state of the TMDS output buffers in the DP dual mode adaptor
+ * @type: DP dual mode adaptor type
+ * @adapter: I2C adapter for the DDC bus
+ * @enabled: current state of the TMDS output buffers
+ *
+ * Get the state of the TMDS output buffers in the adaptor. For
+ * type2 adaptors this is queried from the DP_DUAL_MODE_TMDS_OEN
+ * register. As some type 1 adaptors have problems with registers
+ * (see comments in drm_dp_dual_mode_detect()) we don't read the
+ * register on those, instead we simply assume that the buffers
+ * are always enabled.
+ *
+ * Returns:
+ * 0 on success, negative error code on failure
+ */
+int drm_dp_dual_mode_get_tmds_output(enum drm_dp_dual_mode_type type,
+ struct i2c_adapter *adapter,
+ bool *enabled)
+{
+ uint8_t tmds_oen;
+ ssize_t ret;
+
+ if (type < DRM_DP_DUAL_MODE_TYPE2_DVI) {
+ *enabled = true;
+ return 0;
+ }
+
+ ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_TMDS_OEN,
+ &tmds_oen, sizeof(tmds_oen));
+ if (ret) {
+ DRM_DEBUG_KMS("Failed to query state of TMDS output buffers\n");
+ return ret;
+ }
+
+ *enabled = !(tmds_oen & DP_DUAL_MODE_TMDS_DISABLE);
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_dp_dual_mode_get_tmds_output);
+
+/**
+ * drm_dp_dual_mode_set_tmds_output - Enable/disable TMDS output buffers in the DP dual mode adaptor
+ * @type: DP dual mode adaptor type
+ * @adapter: I2C adapter for the DDC bus
+ * @enable: enable (as opposed to disable) the TMDS output buffers
+ *
+ * Set the state of the TMDS output buffers in the adaptor. For
+ * type2 this is set via the DP_DUAL_MODE_TMDS_OEN register. As
+ * some type 1 adaptors have problems with registers (see comments
+ * in drm_dp_dual_mode_detect()) we avoid touching the register,
+ * making this function a no-op on type 1 adaptors.
+ *
+ * Returns:
+ * 0 on success, negative error code on failure
+ */
+int drm_dp_dual_mode_set_tmds_output(enum drm_dp_dual_mode_type type,
+ struct i2c_adapter *adapter, bool enable)
+{
+ uint8_t tmds_oen = enable ? 0 : DP_DUAL_MODE_TMDS_DISABLE;
+ ssize_t ret;
+
+ if (type < DRM_DP_DUAL_MODE_TYPE2_DVI)
+ return 0;
+
+ ret = drm_dp_dual_mode_write(adapter, DP_DUAL_MODE_TMDS_OEN,
+ &tmds_oen, sizeof(tmds_oen));
+ if (ret) {
+ DRM_DEBUG_KMS("Failed to %s TMDS output buffers\n",
+ enable ? "enable" : "disable");
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_dp_dual_mode_set_tmds_output);
+
+/**
+ * drm_dp_get_dual_mode_type_name - Get the name of the DP dual mode adaptor type as a string
+ * @type: DP dual mode adaptor type
+ *
+ * Returns:
+ * String representation of the DP dual mode adaptor type
+ */
+const char *drm_dp_get_dual_mode_type_name(enum drm_dp_dual_mode_type type)
+{
+ switch (type) {
+ case DRM_DP_DUAL_MODE_NONE:
+ return "none";
+ case DRM_DP_DUAL_MODE_TYPE1_DVI:
+ return "type 1 DVI";
+ case DRM_DP_DUAL_MODE_TYPE1_HDMI:
+ return "type 1 HDMI";
+ case DRM_DP_DUAL_MODE_TYPE2_DVI:
+ return "type 2 DVI";
+ case DRM_DP_DUAL_MODE_TYPE2_HDMI:
+ return "type 2 HDMI";
+ default:
+ WARN_ON(type != DRM_DP_DUAL_MODE_UNKNOWN);
+ return "unknown";
+ }
+}
+EXPORT_SYMBOL(drm_dp_get_dual_mode_type_name);
--- /dev/null
+/*
+ * 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 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
+ */
+
+#ifndef DRM_DP_DUAL_MODE_HELPER_H
+#define DRM_DP_DUAL_MODE_HELPER_H
+
+#include <linux/types.h>
+
+/*
+ * Optional for type 1 DVI adaptors
+ * Mandatory for type 1 HDMI and type 2 adaptors
+ */
+#define DP_DUAL_MODE_HDMI_ID 0x00 /* 00-0f */
+#define DP_DUAL_MODE_HDMI_ID_LEN 16
+/*
+ * Optional for type 1 adaptors
+ * Mandatory for type 2 adaptors
+ */
+#define DP_DUAL_MODE_ADAPTOR_ID 0x10
+#define DP_DUAL_MODE_REV_MASK 0x07
+#define DP_DUAL_MODE_REV_TYPE2 0x00
+#define DP_DUAL_MODE_TYPE_MASK 0xf0
+#define DP_DUAL_MODE_TYPE_TYPE2 0xa0
+#define DP_DUAL_MODE_IEEE_OUI 0x11 /* 11-13*/
+#define DP_DUAL_IEEE_OUI_LEN 3
+#define DP_DUAL_DEVICE_ID 0x14 /* 14-19 */
+#define DP_DUAL_DEVICE_ID_LEN 6
+#define DP_DUAL_MODE_HARDWARE_REV 0x1a
+#define DP_DUAL_MODE_FIRMWARE_MAJOR_REV 0x1b
+#define DP_DUAL_MODE_FIRMWARE_MINOR_REV 0x1c
+#define DP_DUAL_MODE_MAX_TMDS_CLOCK 0x1d
+#define DP_DUAL_MODE_I2C_SPEED_CAP 0x1e
+#define DP_DUAL_MODE_TMDS_OEN 0x20
+#define DP_DUAL_MODE_TMDS_DISABLE 0x01
+#define DP_DUAL_MODE_HDMI_PIN_CTRL 0x21
+#define DP_DUAL_MODE_CEC_ENABLE 0x01
+#define DP_DUAL_MODE_I2C_SPEED_CTRL 0x22
+
+struct i2c_adapter;
+
+ssize_t drm_dp_dual_mode_read(struct i2c_adapter *adapter,
+ u8 offset, void *buffer, size_t size);
+ssize_t drm_dp_dual_mode_write(struct i2c_adapter *adapter,
+ u8 offset, const void *buffer, size_t size);
+
+/**
+ * enum drm_dp_dual_mode_type - Type of the DP dual mode adaptor
+ * @DRM_DP_DUAL_MODE_NONE: No DP dual mode adaptor
+ * @DRM_DP_DUAL_MODE_UNKNOWN: Could be either none or type 1 DVI adaptor
+ * @DRM_DP_DUAL_MODE_TYPE1_DVI: Type 1 DVI adaptor
+ * @DRM_DP_DUAL_MODE_TYPE1_HDMI: Type 1 HDMI adaptor
+ * @DRM_DP_DUAL_MODE_TYPE2_DVI: Type 2 DVI adaptor
+ * @DRM_DP_DUAL_MODE_TYPE2_HDMI: Type 2 HDMI adaptor
+ */
+enum drm_dp_dual_mode_type {
+ DRM_DP_DUAL_MODE_NONE,
+ DRM_DP_DUAL_MODE_UNKNOWN,
+ DRM_DP_DUAL_MODE_TYPE1_DVI,
+ DRM_DP_DUAL_MODE_TYPE1_HDMI,
+ DRM_DP_DUAL_MODE_TYPE2_DVI,
+ DRM_DP_DUAL_MODE_TYPE2_HDMI,
+};
+
+enum drm_dp_dual_mode_type drm_dp_dual_mode_detect(struct i2c_adapter *adapter);
+int drm_dp_dual_mode_max_tmds_clock(enum drm_dp_dual_mode_type type,
+ struct i2c_adapter *adapter);
+int drm_dp_dual_mode_get_tmds_output(enum drm_dp_dual_mode_type type,
+ struct i2c_adapter *adapter, bool *enabled);
+int drm_dp_dual_mode_set_tmds_output(enum drm_dp_dual_mode_type type,
+ struct i2c_adapter *adapter, bool enable);
+const char *drm_dp_get_dual_mode_type_name(enum drm_dp_dual_mode_type type);
+
+#endif
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff