From d1e3b5564834ea24dee6b364a172365f64865fe5 Mon Sep 17 00:00:00 2001 From: Alex Deucher Date: Wed, 21 Aug 2013 13:48:12 -0400 Subject: [PATCH] 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: Alex Deucher --- drivers/gpu/drm/radeon/atombios_i2c.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/radeon/atombios_i2c.c b/drivers/gpu/drm/radeon/atombios_i2c.c index 2ca389d19258..deaf98cdca3a 100644 --- a/drivers/gpu/drm/radeon/atombios_i2c.c +++ b/drivers/gpu/drm/radeon/atombios_i2c.c @@ -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; -- 2.30.2