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Commit d1e3b556 authored by Alex Deucher's avatar Alex Deucher
Browse files

drm/radeon: atombios hw i2c fixes 



These fixes make writes work properly.  Previously
only reads worked.  Note that this feature is off
by default.

Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 95663948

drivers/gpu/drm/radeon/atombios_i2c.c

+8 −4
Original line number Diff line number Diff line
@@ -32,7 +32,7 @@ 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_WRITE 3

#define ATOM_MAX_HW_I2C_READ  255



static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan,
@@ -52,20 +52,24 @@ static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan, 


	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);

			DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 3)\n", num);

			return -EINVAL;

		}

		memcpy(&out, buf, num);

		args.ucRegIndex = buf[0];

		if (num > 1)

			memcpy(&out, &buf[1], num - 1);

		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.ucRegIndex = 0;

		args.lpI2CDataOut = 0;

	}



	args.ucFlag = flags;

	args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;

	args.ucRegIndex = 0;

	args.ucTransBytes = num;

	args.ucSlaveAddr = slave_addr << 1;

	args.ucLineNumber = chan->rec.i2c_id;