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Commit 30388c6e authored by Alex Deucher's avatar Alex Deucher Committed by Dave Airlie
Browse files

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: default avatarAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent 90489557

drivers/gpu/drm/radeon/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -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

drivers/gpu/drm/radeon/atombios_i2c.c

0 → 100644
+139 −0
Original line number Diff line number Diff line 
/*

 * 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;

}

drivers/gpu/drm/radeon/radeon_i2c.c

+21 −0
Original line number Diff line number Diff line
@@ -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),