drm/radeon/kms/dce3+: add support for hw i2c using atom

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>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Alex Deucher 2012-01-20 14:50:18 -05:00 committed by Dave Airlie
parent 9048955748
commit 30388c6e48
3 changed files with 161 additions and 1 deletions

View File

@ -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

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@ -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;
}

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@ -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)
@ -914,6 +923,18 @@ 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),