From: Alex Deucher alexander.deucher@amd.com
Starting with DCE3 hardware, atom contains a general purpose ProcessI2cChannelTransaction similar to ProcessAuxChannelTransaction.
Add an implementation using the atom tables for DCE3+ hardware.
This should be a little less CPU intensive than bit banging and may work better in certain cases.
Enable it by setting the radeon hw_i2c module parameter to 1. E.g., radeon.hw_i2c=1 on the kernel command line in grub.
Signed-off-by: Alex Deucher alexander.deucher@amd.com --- drivers/gpu/drm/radeon/Makefile | 2 +- drivers/gpu/drm/radeon/atombios_i2c.c | 139 +++++++++++++++++++++++++++++++++ drivers/gpu/drm/radeon/radeon_i2c.c | 21 +++++ 3 files changed, 161 insertions(+), 1 deletions(-) create mode 100644 drivers/gpu/drm/radeon/atombios_i2c.c
diff --git a/drivers/gpu/drm/radeon/Makefile b/drivers/gpu/drm/radeon/Makefile index 2139fe8..8410415 100644 --- a/drivers/gpu/drm/radeon/Makefile +++ b/drivers/gpu/drm/radeon/Makefile @@ -71,7 +71,7 @@ radeon-y += radeon_device.o radeon_asic.o radeon_kms.o \ r600_blit_kms.o radeon_pm.o atombios_dp.o r600_audio.o r600_hdmi.o \ evergreen.o evergreen_cs.o evergreen_blit_shaders.o evergreen_blit_kms.o \ radeon_trace_points.o ni.o cayman_blit_shaders.o atombios_encoders.o \ - radeon_semaphore.o radeon_sa.o + radeon_semaphore.o radeon_sa.o atombios_i2c.o
radeon-$(CONFIG_COMPAT) += radeon_ioc32.o radeon-$(CONFIG_VGA_SWITCHEROO) += radeon_atpx_handler.o diff --git a/drivers/gpu/drm/radeon/atombios_i2c.c b/drivers/gpu/drm/radeon/atombios_i2c.c new file mode 100644 index 0000000..44d87b6 --- /dev/null +++ b/drivers/gpu/drm/radeon/atombios_i2c.c @@ -0,0 +1,139 @@ +/* + * Copyright 2011 Advanced Micro Devices, Inc. + * + * 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. + * + * Authors: Alex Deucher + * + */ +#include "drmP.h" +#include "radeon_drm.h" +#include "radeon.h" +#include "atom.h" + +#define TARGET_HW_I2C_CLOCK 50 + +/* these are a limitation of ProcessI2cChannelTransaction not the hw */ +#define ATOM_MAX_HW_I2C_WRITE 2 +#define ATOM_MAX_HW_I2C_READ 255 + +static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan, + u8 slave_addr, u8 flags, + u8 *buf, u8 num) +{ + struct drm_device *dev = chan->dev; + struct radeon_device *rdev = dev->dev_private; + PROCESS_I2C_CHANNEL_TRANSACTION_PS_ALLOCATION args; + int index = GetIndexIntoMasterTable(COMMAND, ProcessI2cChannelTransaction); + unsigned char *base; + u16 out; + + memset(&args, 0, sizeof(args)); + + base = (unsigned char *)rdev->mode_info.atom_context->scratch; + + if (flags & HW_I2C_WRITE) { + if (num > ATOM_MAX_HW_I2C_WRITE) { + DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 2)\n", num); + return -EINVAL; + } + memcpy(&out, buf, num); + args.lpI2CDataOut = cpu_to_le16(out); + } else { + if (num > ATOM_MAX_HW_I2C_READ) { + DRM_ERROR("hw i2c: tried to read too many bytes (%d vs 255)\n", num); + return -EINVAL; + } + } + + args.ucI2CSpeed = TARGET_HW_I2C_CLOCK; + args.ucRegIndex = 0; + args.ucTransBytes = num; + args.ucSlaveAddr = slave_addr << 1; + args.ucLineNumber = chan->rec.i2c_id; + + atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args); + + /* error */ + if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) { + DRM_DEBUG_KMS("hw_i2c error\n"); + return -EIO; + } + + if (!(flags & HW_I2C_WRITE)) + memcpy(buf, base, num); + + return 0; +} + +int radeon_atom_hw_i2c_xfer(struct i2c_adapter *i2c_adap, + struct i2c_msg *msgs, int num) +{ + struct radeon_i2c_chan *i2c = i2c_get_adapdata(i2c_adap); + struct i2c_msg *p; + int i, remaining, current_count, buffer_offset, max_bytes, ret; + u8 buf = 0, flags; + + /* check for bus probe */ + p = &msgs[0]; + if ((num == 1) && (p->len == 0)) { + ret = radeon_process_i2c_ch(i2c, + p->addr, HW_I2C_WRITE, + &buf, 1); + if (ret) + return ret; + else + return num; + } + + for (i = 0; i < num; i++) { + p = &msgs[i]; + remaining = p->len; + buffer_offset = 0; + /* max_bytes are a limitation of ProcessI2cChannelTransaction not the hw */ + if (p->flags & I2C_M_RD) { + max_bytes = ATOM_MAX_HW_I2C_READ; + flags = HW_I2C_READ; + } else { + max_bytes = ATOM_MAX_HW_I2C_WRITE; + flags = HW_I2C_WRITE; + } + while (remaining) { + if (remaining > max_bytes) + current_count = max_bytes; + else + current_count = remaining; + ret = radeon_process_i2c_ch(i2c, + p->addr, flags, + &p->buf[buffer_offset], current_count); + if (ret) + return ret; + remaining -= current_count; + buffer_offset += current_count; + } + } + + return num; +} + +u32 radeon_atom_hw_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c b/drivers/gpu/drm/radeon/radeon_i2c.c index 7bb1b07..bfa32da 100644 --- a/drivers/gpu/drm/radeon/radeon_i2c.c +++ b/drivers/gpu/drm/radeon/radeon_i2c.c @@ -30,6 +30,10 @@ #include "radeon.h" #include "atom.h"
+extern int radeon_atom_hw_i2c_xfer(struct i2c_adapter *i2c_adap, + struct i2c_msg *msgs, int num); +extern u32 radeon_atom_hw_i2c_func(struct i2c_adapter *adap); + /** * radeon_ddc_probe * @@ -882,6 +886,11 @@ static const struct i2c_algorithm radeon_i2c_algo = { .functionality = radeon_hw_i2c_func, };
+static const struct i2c_algorithm radeon_atom_i2c_algo = { + .master_xfer = radeon_atom_hw_i2c_xfer, + .functionality = radeon_atom_hw_i2c_func, +}; + struct radeon_i2c_chan *radeon_i2c_create(struct drm_device *dev, struct radeon_i2c_bus_rec *rec, const char *name) @@ -913,6 +922,18 @@ struct radeon_i2c_chan *radeon_i2c_create(struct drm_device *dev, DRM_ERROR("Failed to register hw i2c %s\n", name); goto out_free; } + } else if (rec->hw_capable && + radeon_hw_i2c && + ASIC_IS_DCE3(rdev)) { + /* hw i2c using atom */ + snprintf(i2c->adapter.name, sizeof(i2c->adapter.name), + "Radeon i2c hw bus %s", name); + i2c->adapter.algo = &radeon_atom_i2c_algo; + ret = i2c_add_adapter(&i2c->adapter); + if (ret) { + DRM_ERROR("Failed to register hw i2c %s\n", name); + goto out_free; + } } else { /* set the radeon bit adapter */ snprintf(i2c->adapter.name, sizeof(i2c->adapter.name),