linux/drivers/gpu/drm/radeon/atombios_i2c.c
Alex Deucher 4543eda521 drm/radeon: fix endian bugs in hw i2c atom routines
Need to swap the data fetched over i2c properly.  This
is the same fix as the endian fix for aux channel
transactions.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
2013-08-30 16:30:38 -04:00

142 lines
4 KiB
C

/*
* 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 <drm/drmP.h>
#include <drm/radeon_drm.h>
#include "radeon.h"
#include "atom.h"
extern void radeon_atom_copy_swap(u8 *dst, u8 *src, u8 num_bytes, bool to_le);
#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))
radeon_atom_copy_swap(buf, base, num, false);
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;
}