On Wed, 01 Feb 2017, Shashank Sharma <shashank.sharma@xxxxxxxxx> wrote: > From: Thierry Reding <treding@xxxxxxxxxx> > > SCDC is a mechanism defined in the HDMI 2.0 specification that allows > the source and sink devices to communicate. > > This commit introduces helpers to access the SCDC and provides the > symbolic names for the various registers defined in the specification. > > Signed-off-by: Thierry Reding <treding@xxxxxxxxxx> One process note, you need to add your own Signed-off-by under the original author's sign-off, even when you're posting them unchanged. Signed-off-by means https://developercertificate.org/ BR, Jani. > --- > Documentation/gpu/drm-kms-helpers.rst | 12 ++++ > drivers/gpu/drm/Makefile | 3 +- > drivers/gpu/drm/drm_scdc_helper.c | 111 ++++++++++++++++++++++++++++ > include/drm/drm_scdc_helper.h | 132 ++++++++++++++++++++++++++++++++++ > 4 files changed, 257 insertions(+), 1 deletion(-) > create mode 100644 drivers/gpu/drm/drm_scdc_helper.c > create mode 100644 include/drm/drm_scdc_helper.h > > diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst > index 03040aa..7592756 100644 > --- a/Documentation/gpu/drm-kms-helpers.rst > +++ b/Documentation/gpu/drm-kms-helpers.rst > @@ -217,6 +217,18 @@ EDID Helper Functions Reference > .. kernel-doc:: drivers/gpu/drm/drm_edid.c > :export: > > +SCDC Helper Functions Reference > +=============================== > + > +.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c > + :doc: scdc helpers > + > +.. kernel-doc:: include/drm/drm_scdc_helper.h > + :internal: > + > +.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c > + :export: > + > Rectangle Utilities Reference > ============================= > > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile > index 92de399..ad91cd9 100644 > --- a/drivers/gpu/drm/Makefile > +++ b/drivers/gpu/drm/Makefile > @@ -31,7 +31,8 @@ drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o > drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \ > drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \ > drm_kms_helper_common.o drm_dp_dual_mode_helper.o \ > - drm_simple_kms_helper.o drm_modeset_helper.o > + drm_simple_kms_helper.o drm_modeset_helper.o \ > + drm_scdc_helper.o > > drm_kms_helper-$(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_scdc_helper.c b/drivers/gpu/drm/drm_scdc_helper.c > new file mode 100644 > index 0000000..fe0e121 > --- /dev/null > +++ b/drivers/gpu/drm/drm_scdc_helper.c > @@ -0,0 +1,111 @@ > +/* > + * Copyright (c) 2015 NVIDIA Corporation. All rights reserved. > + * > + * 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, sub license, > + * 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 NON-INFRINGEMENT. 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 <linux/slab.h> > + > +#include <drm/drm_scdc_helper.h> > + > +/** > + * DOC: scdc helpers > + * > + * Status and Control Data Channel (SCDC) is a mechanism introduced by the > + * HDMI 2.0 specification. It is a point-to-point protocol that allows the > + * HDMI source and HDMI sink to exchange data. The same I2C interface that > + * is used to access EDID serves as the transport mechanism for SCDC. > + */ > + > +#define SCDC_I2C_SLAVE_ADDRESS 0x54 > + > +/** > + * drm_scdc_read - read a block of data from SCDC > + * @adapter: I2C controller > + * @offset: start offset of block to read > + * @buffer: return location for the block to read > + * @size: size of the block to read > + * > + * Reads a block of data from SCDC, starting at a given offset. > + * > + * Returns: > + * The number of bytes read from SCDC or a negative error code on failure. > + */ > +ssize_t drm_scdc_read(struct i2c_adapter *adapter, u8 offset, void *buffer, > + size_t size) > +{ > + struct i2c_msg msgs[2] = { > + { > + .addr = SCDC_I2C_SLAVE_ADDRESS, > + .flags = 0, > + .len = 1, > + .buf = &offset, > + }, { > + .addr = SCDC_I2C_SLAVE_ADDRESS, > + .flags = I2C_M_RD, > + .len = size, > + .buf = buffer, > + } > + }; > + > + return i2c_transfer(adapter, msgs, ARRAY_SIZE(msgs)); > +} > +EXPORT_SYMBOL(drm_scdc_read); > + > +/** > + * drm_scdc_write - write a block of data to SCDC > + * @adapter: I2C controller > + * @offset: start offset of block to write > + * @buffer: block of data to write > + * @size: size of the block to write > + * > + * Writes a block of data to SCDC, starting at a given offset. > + * > + * Returns: > + * The number of bytes written to SCDC or a negative error code on failure. > + */ > +ssize_t drm_scdc_write(struct i2c_adapter *adapter, u8 offset, > + const void *buffer, size_t size) > +{ > + struct i2c_msg msg = { > + .addr = SCDC_I2C_SLAVE_ADDRESS, > + .flags = 0, > + .len = 1 + size, > + .buf = NULL, > + }; > + void *data; > + int err; > + > + data = kmalloc(1 + size, GFP_TEMPORARY); > + if (!data) > + return -ENOMEM; > + > + msg.buf = data; > + > + memcpy(data, &offset, sizeof(offset)); > + memcpy(data + 1, buffer, size); > + > + err = i2c_transfer(adapter, &msg, 1); > + > + kfree(data); > + > + return err; > +} > +EXPORT_SYMBOL(drm_scdc_write); > diff --git a/include/drm/drm_scdc_helper.h b/include/drm/drm_scdc_helper.h > new file mode 100644 > index 0000000..93b07bc > --- /dev/null > +++ b/include/drm/drm_scdc_helper.h > @@ -0,0 +1,132 @@ > +/* > + * Copyright (c) 2015 NVIDIA Corporation. All rights reserved. > + * > + * 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, sub license, > + * 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 NON-INFRINGEMENT. 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. > + */ > + > +#ifndef DRM_SCDC_HELPER_H > +#define DRM_SCDC_HELPER_H > + > +#include <linux/i2c.h> > +#include <linux/types.h> > + > +#define SCDC_SINK_VERSION 0x01 > + > +#define SCDC_SOURCE_VERSION 0x02 > + > +#define SCDC_UPDATE_0 0x10 > +#define SCDC_READ_REQUEST_TEST (1 << 2) > +#define SCDC_CED_UPDATE (1 << 1) > +#define SCDC_STATUS_UPDATE (1 << 0) > + > +#define SCDC_UPDATE_1 0x11 > + > +#define SCDC_TMDS_CONFIG 0x20 > +#define SCDC_TMDS_BIT_CLOCK_RATIO_BY_40 (1 << 1) > +#define SCDC_TMDS_BIT_CLOCK_RATIO_BY_10 (0 << 1) > +#define SCDC_SCRAMBLING_ENABLE (1 << 0) > + > +#define SCDC_SCRAMBLER_STATUS 0x21 > +#define SCDC_SCRAMBLING_STATUS (1 << 0) > + > +#define SCDC_CONFIG_0 0x30 > +#define SCDC_READ_REQUEST_ENABLE (1 << 0) > + > +#define SCDC_STATUS_FLAGS_0 0x40 > +#define SCDC_CH2_LOCK (1 < 3) > +#define SCDC_CH1_LOCK (1 < 2) > +#define SCDC_CH0_LOCK (1 < 1) > +#define SCDC_CH_LOCK_MASK (SCDC_CH2_LOCK | SCDC_CH1_LOCK | SCDC_CH0_LOCK) > +#define SCDC_CLOCK_DETECT (1 << 0) > + > +#define SCDC_STATUS_FLAGS_1 0x41 > + > +#define SCDC_ERR_DET_0_L 0x50 > +#define SCDC_ERR_DET_0_H 0x51 > +#define SCDC_ERR_DET_1_L 0x52 > +#define SCDC_ERR_DET_1_H 0x53 > +#define SCDC_ERR_DET_2_L 0x54 > +#define SCDC_ERR_DET_2_H 0x55 > +#define SCDC_CHANNEL_VALID (1 << 7) > + > +#define SCDC_ERR_DET_CHECKSUM 0x56 > + > +#define SCDC_TEST_CONFIG_0 0xc0 > +#define SCDC_TEST_READ_REQUEST (1 << 7) > +#define SCDC_TEST_READ_REQUEST_DELAY(x) ((x) & 0x7f) > + > +#define SCDC_MANUFACTURER_IEEE_OUI 0xd0 > +#define SCDC_MANUFACTURER_IEEE_OUI_SIZE 3 > + > +#define SCDC_DEVICE_ID 0xd3 > +#define SCDC_DEVICE_ID_SIZE 8 > + > +#define SCDC_DEVICE_HARDWARE_REVISION 0xdb > +#define SCDC_DEVICE_HARDWARE_REVISION_MAJOR(x) (((x) >> 4) & 0xf) > +#define SCDC_DEVICE_HARDWARE_REVISION_MINOR(x) (((x) >> 0) & 0xf) > + > +#define SCDC_DEVICE_SOFTWARE_MAJOR_REVISION 0xdc > +#define SCDC_DEVICE_SOFTWARE_MINOR_REVISION 0xdd > + > +#define SCDC_MANUFACTURER_SPECIFIC 0xde > +#define SCDC_MANUFACTURER_SPECIFIC_SIZE 34 > + > +ssize_t drm_scdc_read(struct i2c_adapter *adapter, u8 offset, void *buffer, > + size_t size); > +ssize_t drm_scdc_write(struct i2c_adapter *adapter, u8 offset, > + const void *buffer, size_t size); > + > +/** > + * drm_scdc_readb - read a single byte from SCDC > + * @adapter: I2C adapter > + * @offset: offset of register to read > + * @value: return location for the register value > + * > + * Reads a single byte from SCDC. This is a convenience wrapper around the > + * drm_scdc_read() function. > + * > + * Returns: > + * 0 on success or a negative error code on failure. > + */ > +static inline int drm_scdc_readb(struct i2c_adapter *adapter, u8 offset, > + u8 *value) > +{ > + return drm_scdc_read(adapter, offset, value, sizeof(*value)); > +} > + > +/** > + * drm_scdc_writeb - write a single byte to SCDC > + * @adapter: I2C adapter > + * @offset: offset of register to read > + * @value: return location for the register value > + * > + * Writes a single byte to SCDC. This is a convenience wrapper around the > + * drm_scdc_write() function. > + * > + * Returns: > + * 0 on success or a negative error code on failure. > + */ > +static inline int drm_scdc_writeb(struct i2c_adapter *adapter, u8 offset, > + u8 value) > +{ > + return drm_scdc_write(adapter, offset, &value, sizeof(value)); > +} > + > +#endif -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
