| Message ID | 1456245988-19442-2-git-send-email-ville.syrjala@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Em Ter, 2016-02-23 às 18:46 +0200, ville.syrjala@linux.intel.com escreveu: > From: Ville Syrjälä <ville.syrjala@linux.intel.com> > > Add a helper which aids in he identification of DP dual mode (aka. > DP++) > adaptors. There are several types of adaptors specified: > type 1 DVI, type 1 HDMI, type 2 DVI, type 2 HDMI > > Type 1 adaptors have a max TMDS clock limit of 165MHz, type 2 > adaptors > may go as high as 300MHz and they provide a register informing the > source device what the actual limit is. Supposedly also type 1 > adaptors > may optionally implement this register. This TMDS clock limit is the > main reason why we need to identify these adaptors. > > Type 1 adaptors provide access to their internal registers and the > sink > DDC bus through I2C. Type 2 adaptors provide this access both via I2C > and I2C-over-AUX. A type 2 source device may choose to implement > either > or both of these methods. If a source device implements only the > I2C-over-AUX method, then the driver will obviously need specific > support for such adaptors since the port is driven like an HDMI port, > but DDC communication happes over the AUX channel. > > This helper should be enough to identify the adaptor type (some > type 1 DVI adaptors may be a slight exception) and the maximum TMDS > clock limit. Another feature that may be available is control over > the TMDS output buffers on the adaptor, possibly allowing for some > power saving when the TMDS link is down. > > Other user controllable features that may be available in the > adaptors > are downstream i2c bus speed control when using i2c-over-aux, and > some control over the CEC pin. I chose not to provide any helper > functions for those since I have no use for them in i915 at this > time. > The rest of the registers in the adaptor are mostly just information, > eg. IEEE OUI, hardware and firmware revision, etc. Please run a spell checker and do some proof-reading both in the commit message and in the code comments. Multiple instances of "sizo", "Hoever", "adator", "Identyfy", etc. I also spotted some typos in the next commits. > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > --- > drivers/gpu/drm/Makefile | 2 +- > drivers/gpu/drm/drm_dp_dual_mode_helper.c | 328 > ++++++++++++++++++++++++++++++ > include/drm/drm_dp_dual_mode_helper.h | 80 ++++++++ > 3 files changed, 409 insertions(+), 1 deletion(-) > create mode 100644 drivers/gpu/drm/drm_dp_dual_mode_helper.c > create mode 100644 include/drm/drm_dp_dual_mode_helper.h > > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile > index 6eb94fc561dc..22228ef50f36 100644 > --- a/drivers/gpu/drm/Makefile > +++ b/drivers/gpu/drm/Makefile > @@ -23,7 +23,7 @@ drm-$(CONFIG_AGP) += drm_agpsupport.o > > drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o > drm_probe_helper.o \ > drm_plane_helper.o drm_dp_mst_topology.o > drm_atomic_helper.o \ > - drm_kms_helper_common.o > + drm_kms_helper_common.o drm_dp_dual_mode_helper.o > > drm_kms_helper-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o > drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o > diff --git a/drivers/gpu/drm/drm_dp_dual_mode_helper.c > b/drivers/gpu/drm/drm_dp_dual_mode_helper.c > new file mode 100644 > index 000000000000..bfe511c09568 > --- /dev/null > +++ b/drivers/gpu/drm/drm_dp_dual_mode_helper.c > @@ -0,0 +1,328 @@ > +/* > + * 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 (aka. DP++) adaptor helpers > + * > + * Helper functions to deal with DP dual mode 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 one > or > + * both 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; No retries needed here or below? (asking this due to the comment in drm_edid.c about retries) > + > + return 0; > +} > + > +/** > + * 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; > +} > + > +/** > + * drm_dp_dual_mode_detect - Identyfy 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_NONE it's not So how about adding a new or just renaming it to DRM_DP_DUAL_MODE_UNKNOWN? Let's not assume everybody is going to read the docs. > + * 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_NONE; > + > + /* > + * 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). So shouldn't we just try to read from 0x00 to 0x1F in a single shot? Would this work for your specific adaptor? It would be interesting to know. > 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 || (adaptor_id != (DP_DUAL_MODE_TYPE_TYPE2 | > + DP_DUAL_MODE_REV_TYPE2))) { > + if (is_hdmi_adaptor(hdmi_id)) > + return DRM_DP_DUAL_MODE_TYPE1_HDMI; > + else > + return DRM_DP_DUAL_MODE_TYPE1_DVI; > + } else { > + if (is_hdmi_adaptor(hdmi_id)) > + return DRM_DP_DUAL_MODE_TYPE2_HDMI; > + else > + return DRM_DP_DUAL_MODE_TYPE2_DVI; > + } > +} > +EXPORT_SYMBOL(drm_dp_dual_mode_detect); > + > +/** > + * drm_dp_dual_mode_max_tmds_clock - Max TMDS clock for DP dual mode > adaptor > + * adapter: I2C adapter for the DDC bus > + * > + * Determine the max TMDS clock the adaptor supports based on the > + * DP_DUAL_MODE_MAX_TMDS_CLOCK register. The register is mandatory > for > + * type 2 adaptors, optional for type 1 adaptors. Hoever, as some > type 1 > + * adaptors are broken (see comments in drm_dp_dual_mode_detect() > for the > + * details) one probably shouldn't use this with type 1 adaptors at > all. > + * Type 1 adaptors should anyway be always limited to 165 MHz. I always assume programmers are as bad as possible, so I wonder if we should just also call drm_dp_dual_mode_detect() here. Also try the trick of reading the whole thing at once instead of the specific address. Same goes for the other functions. I also see that this would make patches 2-4 different, so this is just an idea, not a requirement. > + * > + * Returns: > + * Maximum supported TMDS clock rate for the DP dual mode adaptor in > kHz. > + */ > +int drm_dp_dual_mode_max_tmds_clock(struct i2c_adapter *adapter) > +{ > + uint8_t max_tmds_clock; > + ssize_t ret; > + > + /* > + * Type 1 adaptors are limited to 165MHz > > + * Type 2 adaptors can tells us their limit "can tells" > + */ > + ret = drm_dp_dual_mode_read(adapter, > DP_DUAL_MODE_MAX_TMDS_CLOCK, > + &max_tmds_clock, > sizeof(max_tmds_clock)); > + if (ret) Maybe also "if (ret || max_tmds_clock == 0 || max_tmds_clock == 0xFF)"? > + 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 > + * 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. > + * DP_DUAL_MODE_TMDS_OEN register is mandatory for type 2 adaptors, > + * optionals for type 1 adaptors. Hoever, as some type 1 adaptors > are > + * broken (see comments in drm_dp_dual_mode_detect() for the > details) > + * one probably shouldn't use this with type 1 adaptors at all. > + * > + * Returns: > + * 0 on success, negative error code on failure > + */ > +int drm_dp_dual_mode_get_tmds_output(struct i2c_adapter *adapter, > bool *enabled) > +{ > + uint8_t tmds_oen; > + ssize_t ret; > + > + ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_TMDS_OEN, > + &tmds_oen, sizeof(tmds_oen)); > + if (ret) > + 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 > + * 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. > + * DP_DUAL_MODE_TMDS_OEN register is mandatory for type 2 adaptors, > + * optionals for type 1 adaptors. Hoever, as some type 1 adaptors > are > + * broken (see comments in drm_dp_dual_mode_detect() for the > details) > + * one probably shouldn't use this with type 1 adaptors at all. > + * > + * Returns: > + * 0 on success, negative error code on failure > + */ > +int drm_dp_dual_mode_set_tmds_output(struct i2c_adapter *adapter, > bool enable) > +{ > + uint8_t tmds_oen = enable ? 0 : DP_DUAL_MODE_TMDS_DISABLE; > + ssize_t ret; > + > + ret = drm_dp_dual_mode_write(adapter, DP_DUAL_MODE_TMDS_OEN, > + &tmds_oen, sizeof(tmds_oen)); > + if (ret) > + 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: > + return "unknown"; Please at least WARN_ON(1)? And, if you implement my suggestion of adding an actual unknown value to the enum, don't forget to change the default case to return something that's not "unknown". Most of the things I wrote above are just ideas, not requirements, and having this patch as-is looks better than not having it, so if you at least fix the spelling errors: Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com> > + }; > + > +} > +EXPORT_SYMBOL(drm_dp_get_dual_mode_type_name); > diff --git a/include/drm/drm_dp_dual_mode_helper.h > b/include/drm/drm_dp_dual_mode_helper.h > new file mode 100644 > index 000000000000..a2f6b4587f5f > --- /dev/null > +++ b/include/drm/drm_dp_dual_mode_helper.h > @@ -0,0 +1,80 @@ > +/* > + * 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 adators > + */ > +#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 adators > + */ > +#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 > +#define DP_DUAL_MODE_LAST_RESERVED 0xff > + > +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 { > + DRM_DP_DUAL_MODE_NONE, > + 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(struct i2c_adapter *adapter); > +int drm_dp_dual_mode_get_tmds_output(struct i2c_adapter *adapter, > bool *enabled); > +int drm_dp_dual_mode_set_tmds_output(struct i2c_adapter *adapter, > bool enable); > +const char *drm_dp_get_dual_mode_type_name(enum > drm_dp_dual_mode_type type); > + > +#endif
On Thu, Mar 31, 2016 at 07:25:36PM +0000, Zanoni, Paulo R wrote: > Em Ter, 2016-02-23 às 18:46 +0200, ville.syrjala@linux.intel.com > escreveu: > > From: Ville Syrjälä <ville.syrjala@linux.intel.com> > > > > Add a helper which aids in he identification of DP dual mode (aka. > > DP++) > > adaptors. There are several types of adaptors specified: > > type 1 DVI, type 1 HDMI, type 2 DVI, type 2 HDMI > > > > Type 1 adaptors have a max TMDS clock limit of 165MHz, type 2 > > adaptors > > may go as high as 300MHz and they provide a register informing the > > source device what the actual limit is. Supposedly also type 1 > > adaptors > > may optionally implement this register. This TMDS clock limit is the > > main reason why we need to identify these adaptors. > > > > Type 1 adaptors provide access to their internal registers and the > > sink > > DDC bus through I2C. Type 2 adaptors provide this access both via I2C > > and I2C-over-AUX. A type 2 source device may choose to implement > > either > > or both of these methods. If a source device implements only the > > I2C-over-AUX method, then the driver will obviously need specific > > support for such adaptors since the port is driven like an HDMI port, > > but DDC communication happes over the AUX channel. > > > > This helper should be enough to identify the adaptor type (some > > type 1 DVI adaptors may be a slight exception) and the maximum TMDS > > clock limit. Another feature that may be available is control over > > the TMDS output buffers on the adaptor, possibly allowing for some > > power saving when the TMDS link is down. > > > > Other user controllable features that may be available in the > > adaptors > > are downstream i2c bus speed control when using i2c-over-aux, and > > some control over the CEC pin. I chose not to provide any helper > > functions for those since I have no use for them in i915 at this > > time. > > The rest of the registers in the adaptor are mostly just information, > > eg. IEEE OUI, hardware and firmware revision, etc. > > Please run a spell checker and do some proof-reading both in the commit > message and in the code comments. Multiple instances of "sizo", > "Hoever", "adator", "Identyfy", etc. I also spotted some typos in the > next commits. > > > > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > > --- > > drivers/gpu/drm/Makefile | 2 +- > > drivers/gpu/drm/drm_dp_dual_mode_helper.c | 328 > > ++++++++++++++++++++++++++++++ > > include/drm/drm_dp_dual_mode_helper.h | 80 ++++++++ > > 3 files changed, 409 insertions(+), 1 deletion(-) > > create mode 100644 drivers/gpu/drm/drm_dp_dual_mode_helper.c > > create mode 100644 include/drm/drm_dp_dual_mode_helper.h > > > > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile > > index 6eb94fc561dc..22228ef50f36 100644 > > --- a/drivers/gpu/drm/Makefile > > +++ b/drivers/gpu/drm/Makefile > > @@ -23,7 +23,7 @@ drm-$(CONFIG_AGP) += drm_agpsupport.o > > > > drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o > > drm_probe_helper.o \ > > drm_plane_helper.o drm_dp_mst_topology.o > > drm_atomic_helper.o \ > > - drm_kms_helper_common.o > > + drm_kms_helper_common.o drm_dp_dual_mode_helper.o > > > > drm_kms_helper-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o > > drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o > > diff --git a/drivers/gpu/drm/drm_dp_dual_mode_helper.c > > b/drivers/gpu/drm/drm_dp_dual_mode_helper.c > > new file mode 100644 > > index 000000000000..bfe511c09568 > > --- /dev/null > > +++ b/drivers/gpu/drm/drm_dp_dual_mode_helper.c > > @@ -0,0 +1,328 @@ > > +/* > > + * 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 (aka. DP++) adaptor helpers > > + * > > + * Helper functions to deal with DP dual mode 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 one > > or > > + * both 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; > > No retries needed here or below? (asking this due to the comment in > drm_edid.c about retries) The EDID retries are mostly cargo culted. I suspect you don't really need them unless the connector is about to fall off, or the wiring is made of cotton. > > > + > > + return 0; > > +} > > + > > +/** > > + * 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; > > +} > > + > > +/** > > + * drm_dp_dual_mode_detect - Identyfy 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_NONE it's not > > So how about adding a new or just renaming it to > DRM_DP_DUAL_MODE_UNKNOWN? Let's not assume everybody is going to read > the docs. I suppose adding an extra enum value can't hurt. > > > + * 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_NONE; > > + > > + /* > > + * 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). > > So shouldn't we just try to read from 0x00 to 0x1F in a single shot? > Would this work for your specific adaptor? It would be interesting to > know. I think I did consider that after giving up on another strange detection scheme that would have perhaps allowed me to detect decent type 1 adaptors. IIRC the adaptors I tested returned 0x00 or 0xff for the 0x10-0x20 range when doing a single read, but I suspect they might as well just wrap after 0x0f since the spec says they don't need to implement anything beyond 0x00-0x0f. While all of those results would work just as well as reading the single byte, I decided that there's no point in doing that since I had not seem a single sane type 1 adaptor. They're clearly all just bottom of the barrel hardware so seems unlikely anyone would go to the effort of implementing one decently. So in the end I just figured that minimizing the amount of data we have to read is the sane thing to do. > > > > 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 || (adaptor_id != (DP_DUAL_MODE_TYPE_TYPE2 | > > + DP_DUAL_MODE_REV_TYPE2))) { > > + if (is_hdmi_adaptor(hdmi_id)) > > + return DRM_DP_DUAL_MODE_TYPE1_HDMI; > > + else > > + return DRM_DP_DUAL_MODE_TYPE1_DVI; > > + } else { > > + if (is_hdmi_adaptor(hdmi_id)) > > + return DRM_DP_DUAL_MODE_TYPE2_HDMI; > > + else > > + return DRM_DP_DUAL_MODE_TYPE2_DVI; > > + } > > +} > > +EXPORT_SYMBOL(drm_dp_dual_mode_detect); > > + > > +/** > > + * drm_dp_dual_mode_max_tmds_clock - Max TMDS clock for DP dual mode > > adaptor > > + * adapter: I2C adapter for the DDC bus > > + * > > + * Determine the max TMDS clock the adaptor supports based on the > > + * DP_DUAL_MODE_MAX_TMDS_CLOCK register. The register is mandatory > > for > > + * type 2 adaptors, optional for type 1 adaptors. Hoever, as some > > type 1 > > + * adaptors are broken (see comments in drm_dp_dual_mode_detect() > > for the > > + * details) one probably shouldn't use this with type 1 adaptors at > > all. > > + * Type 1 adaptors should anyway be always limited to 165 MHz. > > I always assume programmers are as bad as possible, so I wonder if we > should just also call drm_dp_dual_mode_detect() here. This crossed my mind but I didn't want to slow down things needlessly. I did in fact consider that we might want to raise the abstraction level a bit and introduce some kind of dp_dual_mode object that keeps around the relevant information/state and would allow drivers to avoid the type checks and whatnot. Unfortunately those cursed type 1 DVI adaptors would still require the driver to step in if the detection fails to find anything, so we'd need a callback into the driver or something. And so, since the driver anyway has to deal with the type 1 DVI adaptors, I decided that trying to hide these sort of details inside the helper is pretty much pointless. > Also try the > trick of reading the whole thing at once instead of the specific > address. Same goes for the other functions. I also see that this would > make patches 2-4 different, so this is just an idea, not a requirement. As I suspect some adaptors might just wrap around at 0xf, doing a big read doesn't feel entirely safe here. > > > + * > > + * Returns: > > + * Maximum supported TMDS clock rate for the DP dual mode adaptor in > > kHz. > > + */ > > +int drm_dp_dual_mode_max_tmds_clock(struct i2c_adapter *adapter) > > +{ > > + uint8_t max_tmds_clock; > > + ssize_t ret; > > + > > + /* > > + * Type 1 adaptors are limited to 165MHz > > > > + * Type 2 adaptors can tells us their limit > > "can tells" > > > + */ > > + ret = drm_dp_dual_mode_read(adapter, > > DP_DUAL_MODE_MAX_TMDS_CLOCK, > > + &max_tmds_clock, > > sizeof(max_tmds_clock)); > > + if (ret) > > Maybe also "if (ret || max_tmds_clock == 0 || max_tmds_clock == 0xFF)"? That would seem sensible indeed. > > > > + 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 > > + * 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. > > + * DP_DUAL_MODE_TMDS_OEN register is mandatory for type 2 adaptors, > > + * optionals for type 1 adaptors. Hoever, as some type 1 adaptors > > are > > + * broken (see comments in drm_dp_dual_mode_detect() for the > > details) > > + * one probably shouldn't use this with type 1 adaptors at all. > > + * > > + * Returns: > > + * 0 on success, negative error code on failure > > + */ > > +int drm_dp_dual_mode_get_tmds_output(struct i2c_adapter *adapter, > > bool *enabled) > > +{ > > + uint8_t tmds_oen; > > + ssize_t ret; > > + > > + ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_TMDS_OEN, > > + &tmds_oen, sizeof(tmds_oen)); > > + if (ret) > > + 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 > > + * 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. > > + * DP_DUAL_MODE_TMDS_OEN register is mandatory for type 2 adaptors, > > + * optionals for type 1 adaptors. Hoever, as some type 1 adaptors > > are > > + * broken (see comments in drm_dp_dual_mode_detect() for the > > details) > > + * one probably shouldn't use this with type 1 adaptors at all. > > + * > > + * Returns: > > + * 0 on success, negative error code on failure > > + */ > > +int drm_dp_dual_mode_set_tmds_output(struct i2c_adapter *adapter, > > bool enable) > > +{ > > + uint8_t tmds_oen = enable ? 0 : DP_DUAL_MODE_TMDS_DISABLE; > > + ssize_t ret; > > + > > + ret = drm_dp_dual_mode_write(adapter, DP_DUAL_MODE_TMDS_OEN, > > + &tmds_oen, sizeof(tmds_oen)); > > + if (ret) > > + 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: > > + return "unknown"; > > Please at least WARN_ON(1)? We don't generally warn in these case (in the drm core). > > And, if you implement my suggestion of adding an actual unknown value > to the enum, don't forget to change the default case to return > something that's not "unknown". > > Most of the things I wrote above are just ideas, not requirements, and > having this patch as-is looks better than not having it, so if you at > least fix the spelling errors: > > Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com> > > > + }; > > + > > +} > > +EXPORT_SYMBOL(drm_dp_get_dual_mode_type_name); > > diff --git a/include/drm/drm_dp_dual_mode_helper.h > > b/include/drm/drm_dp_dual_mode_helper.h > > new file mode 100644 > > index 000000000000..a2f6b4587f5f > > --- /dev/null > > +++ b/include/drm/drm_dp_dual_mode_helper.h > > @@ -0,0 +1,80 @@ > > +/* > > + * 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 adators > > + */ > > +#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 adators > > + */ > > +#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 > > +#define DP_DUAL_MODE_LAST_RESERVED 0xff > > + > > +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 { > > + DRM_DP_DUAL_MODE_NONE, > > + 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(struct i2c_adapter *adapter); > > +int drm_dp_dual_mode_get_tmds_output(struct i2c_adapter *adapter, > > bool *enabled); > > +int drm_dp_dual_mode_set_tmds_output(struct i2c_adapter *adapter, > > bool enable); > > +const char *drm_dp_get_dual_mode_type_name(enum > > drm_dp_dual_mode_type type); > > + > > +#endif
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 6eb94fc561dc..22228ef50f36 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -23,7 +23,7 @@ drm-$(CONFIG_AGP) += drm_agpsupport.o drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \ drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \ - drm_kms_helper_common.o + drm_kms_helper_common.o drm_dp_dual_mode_helper.o drm_kms_helper-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o diff --git a/drivers/gpu/drm/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/drm_dp_dual_mode_helper.c new file mode 100644 index 000000000000..bfe511c09568 --- /dev/null +++ b/drivers/gpu/drm/drm_dp_dual_mode_helper.c @@ -0,0 +1,328 @@ +/* + * 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 (aka. DP++) adaptor helpers + * + * Helper functions to deal with DP dual mode 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 one or + * both 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; +} + +/** + * 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; +} + +/** + * drm_dp_dual_mode_detect - Identyfy 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_NONE 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_NONE; + + /* + * 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 || (adaptor_id != (DP_DUAL_MODE_TYPE_TYPE2 | + DP_DUAL_MODE_REV_TYPE2))) { + if (is_hdmi_adaptor(hdmi_id)) + return DRM_DP_DUAL_MODE_TYPE1_HDMI; + else + return DRM_DP_DUAL_MODE_TYPE1_DVI; + } else { + if (is_hdmi_adaptor(hdmi_id)) + return DRM_DP_DUAL_MODE_TYPE2_HDMI; + else + return DRM_DP_DUAL_MODE_TYPE2_DVI; + } +} +EXPORT_SYMBOL(drm_dp_dual_mode_detect); + +/** + * drm_dp_dual_mode_max_tmds_clock - Max TMDS clock for DP dual mode adaptor + * adapter: I2C adapter for the DDC bus + * + * Determine the max TMDS clock the adaptor supports based on the + * DP_DUAL_MODE_MAX_TMDS_CLOCK register. The register is mandatory for + * type 2 adaptors, optional for type 1 adaptors. Hoever, as some type 1 + * adaptors are broken (see comments in drm_dp_dual_mode_detect() for the + * details) one probably shouldn't use this with type 1 adaptors at all. + * Type 1 adaptors should anyway be always limited to 165 MHz. + * + * Returns: + * Maximum supported TMDS clock rate for the DP dual mode adaptor in kHz. + */ +int drm_dp_dual_mode_max_tmds_clock(struct i2c_adapter *adapter) +{ + uint8_t max_tmds_clock; + ssize_t ret; + + /* + * Type 1 adaptors are limited to 165MHz + * Type 2 adaptors can tells us their limit + */ + ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_MAX_TMDS_CLOCK, + &max_tmds_clock, sizeof(max_tmds_clock)); + if (ret) + 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 + * 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. + * DP_DUAL_MODE_TMDS_OEN register is mandatory for type 2 adaptors, + * optionals for type 1 adaptors. Hoever, as some type 1 adaptors are + * broken (see comments in drm_dp_dual_mode_detect() for the details) + * one probably shouldn't use this with type 1 adaptors at all. + * + * Returns: + * 0 on success, negative error code on failure + */ +int drm_dp_dual_mode_get_tmds_output(struct i2c_adapter *adapter, bool *enabled) +{ + uint8_t tmds_oen; + ssize_t ret; + + ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_TMDS_OEN, + &tmds_oen, sizeof(tmds_oen)); + if (ret) + 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 + * 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. + * DP_DUAL_MODE_TMDS_OEN register is mandatory for type 2 adaptors, + * optionals for type 1 adaptors. Hoever, as some type 1 adaptors are + * broken (see comments in drm_dp_dual_mode_detect() for the details) + * one probably shouldn't use this with type 1 adaptors at all. + * + * Returns: + * 0 on success, negative error code on failure + */ +int drm_dp_dual_mode_set_tmds_output(struct i2c_adapter *adapter, bool enable) +{ + uint8_t tmds_oen = enable ? 0 : DP_DUAL_MODE_TMDS_DISABLE; + ssize_t ret; + + ret = drm_dp_dual_mode_write(adapter, DP_DUAL_MODE_TMDS_OEN, + &tmds_oen, sizeof(tmds_oen)); + if (ret) + 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: + return "unknown"; + }; + +} +EXPORT_SYMBOL(drm_dp_get_dual_mode_type_name); diff --git a/include/drm/drm_dp_dual_mode_helper.h b/include/drm/drm_dp_dual_mode_helper.h new file mode 100644 index 000000000000..a2f6b4587f5f --- /dev/null +++ b/include/drm/drm_dp_dual_mode_helper.h @@ -0,0 +1,80 @@ +/* + * 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 adators + */ +#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 adators + */ +#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 +#define DP_DUAL_MODE_LAST_RESERVED 0xff + +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 { + DRM_DP_DUAL_MODE_NONE, + 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(struct i2c_adapter *adapter); +int drm_dp_dual_mode_get_tmds_output(struct i2c_adapter *adapter, bool *enabled); +int drm_dp_dual_mode_set_tmds_output(struct i2c_adapter *adapter, bool enable); +const char *drm_dp_get_dual_mode_type_name(enum drm_dp_dual_mode_type type); + +#endif