Re: [PATCH v3 03/26] drm/i915/writeback: Add writeback registers

["Borah, Chaitanya Kumar" <chaitanya.kumar.borah@intel.com>]

On 3/25/2026 4:37 PM, Suraj Kandpal wrote:
> Add writeback registers to its own file.
> 
> Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
> Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com>
> ---
>   .../drm/i915/display/intel_writeback_reg.h    | 136 ++++++++++++++++++
>   1 file changed, 136 insertions(+)
>   create mode 100644 drivers/gpu/drm/i915/display/intel_writeback_reg.h
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_writeback_reg.h b/drivers/gpu/drm/i915/display/intel_writeback_reg.h
> new file mode 100644
> index 000000000000..ffe302ef3dd9
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/display/intel_writeback_reg.h
> @@ -0,0 +1,136 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2024 Intel Corporation
> + */
> +
> +#ifndef __INTEL_WRITEBACK_REGS_H__
> +#define __INTEL_WRITEBACK_REGS_H__
> +
> +#include "intel_display_reg_defs.h"
> +
> +/* WD 0 and 1 */
> +#define TRANSCODER_WD0_OFFSET	0x6e000
> +#define TRANSCODER_WD1_OFFSET	0x6d800
> +
> +/* WD 0 and 1 */
> +#define PIPE_WD0_OFFSET		0x7e008
> +#define PIPE_WD1_OFFSET		0x7d008
> +
> +/* Gen12 WD */
> +#define _MMIO_WD(tc, wd0, wd1)	_MMIO_TRANS((tc) - TRANSCODER_WD_0, wd0, wd1)
> +
> +#define WD_TRANS_ENABLE		REG_BIT(31)
> +#define WD_TRANS_STATE		REG_BIT(30)
> +
> +/* WD transcoder control */
> +#define _WD_TRANS_FUNC_CTL_0	0x6e400
> +#define _WD_TRANS_FUNC_CTL_1	0x6ec00
> +#define WD_TRANS_FUNC_CTL(tc)	_MMIO_WD(tc,\
> +				_WD_TRANS_FUNC_CTL_0,\
> +				_WD_TRANS_FUNC_CTL_1)

s/TRANS_WD_FUNC_CTL/WD_TRANS_FUNC_CTL

> +

No blank line in between register and it's content.

> +#define TRANS_WD_FUNC_ENABLE		REG_BIT(31)
> +#define WD_TRIGGERED_CAP_MODE_ENABLE	REG_BIT(30)
> +#define START_TRIGGER_FRAME		REG_BIT(29)
> +#define STOP_TRIGGER_FRAME		REG_BIT(28)
> +#define WD_INPUT_SELECT_MASK		REG_GENMASK(14, 12)

maintain bit order.

> +#define WD_INPUT_PIPE_A			REG_FIELD_PREP(WD_INPUT_SELECT_MASK, 0)
> +#define WD_INPUT_PIPE_B			REG_FIELD_PREP(WD_INPUT_SELECT_MASK, 5)
> +#define WD_INPUT_PIPE_C			REG_FIELD_PREP(WD_INPUT_SELECT_MASK, 6)
> +#define WD_INPUT_PIPE_D			REG_FIELD_PREP(WD_INPUT_SELECT_MASK, 7)
> +#define WD_COLOR_MODE_MASK		REG_GENMASK(22, 20)
> +#define WD_CONTROL_POINTERS             REG_GENMASK(19, 18)
> +#define WD_DISABLE_POINTERS             REG_FIELD_PREP(WD_CONTROL_POINTERS, 3)
> +#define WD_PIX_FMT_YUYV			REG_FIELD_PREP(WD_COLOR_MODE_MASK, 1)
> +#define WD_PIX_FMT_XYUV8888		REG_FIELD_PREP(WD_COLOR_MODE_MASK, 2)
> +#define WD_PIX_FMT_XBGR8888		REG_FIELD_PREP(WD_COLOR_MODE_MASK, 3)
> +#define WD_PIX_FMT_Y410			REG_FIELD_PREP(WD_COLOR_MODE_MASK, 4)
> +#define WD_PIX_FMT_YUV422		REG_FIELD_PREP(WD_COLOR_MODE_MASK, 5)
> +#define WD_PIX_FMT_XBGR2101010		REG_FIELD_PREP(WD_COLOR_MODE_MASK, 6)
> +#define WD_PIX_FMT_RGB565		REG_FIELD_PREP(WD_COLOR_MODE_MASK, 7)
> +#define WD_FRAME_NUMBER_MASK		REG_GENMASK(3, 0)
> +#define WD_FRAME_NUMBER(n)		REG_FIELD_PREP(WD_FRAME_NUMBER_MASK, n)
> +

Indent the register content macros using two extra spaces between 
#define and the macro name.

> +#define _WD_STRIDE_0			0x6e510
> +#define _WD_STRIDE_1			0x6ed10
> +#define WD_STRIDE(tc)			_MMIO_WD(tc,\
> +					_WD_STRIDE_0,\
> +					_WD_STRIDE_1)
> +#define WD_STRIDE_MASK			REG_GENMASK(15, 6)

Probably not needed.

> +
> +#define _WD_STREAMCAP_CTL0		0x6e590
> +#define _WD_STREAMCAP_CTL1		0x6ed90
> +#define WD_STREAMCAP_CTL(tc)		_MMIO_WD(tc,\
> +					_WD_STREAMCAP_CTL0,\
> +					_WD_STREAMCAP_CTL1)
> +
> +#define WD_STREAM_CAP_MODE_EN		REG_BIT(31)
> +#define WD_SLICING_STRAT_MASK		REG_GENMASK(25, 24)
> +#define WD_SLICING_STRAT_1_1		REG_FIELD_PREP(WD_SLICING_STRAT_MASK, 0)
> +#define WD_SLICING_STRAT_2_1		REG_FIELD_PREP(WD_SLICING_STRAT_MASK, 1)
> +#define WD_SLICING_STRAT_4_1		REG_FIELD_PREP(WD_SLICING_STRAT_MASK, 2)
> +#define WD_SLICING_STRAT_8_1		REG_FIELD_PREP(WD_SLICING_STRAT_MASK, 3)
> +#define WD_STREAM_OVERRUN_STATUS	1

REG_BIT(0)

> +
> +#define _WD_SURF_0			0x6e514
> +#define _WD_SURF_1			0x6ed14
> +#define WD_SURF(tc)			_MMIO_WD(tc,\
> +					_WD_SURF_0,\
> +					_WD_SURF_1)
> +
> +#define _WD_IMR_0			0x6e560
> +#define _WD_IMR_1			0x6ed60
> +#define WD_IMR(tc)			_MMIO_WD(tc,\
> +					_WD_IMR_0,\
> +					_WD_IMR_1)
> +#define WD_FRAME_COMPLETE_INT		REG_BIT(7)
> +#define WD_GTT_FAULT_INT		REG_BIT(6)
> +#define WD_VBLANK_INT			REG_BIT(5)
> +#define WD_OVERRUN_INT			REG_BIT(4)
> +#define WD_CAPTURING_INT		REG_BIT(3)
> +#define WD_WRITE_COMPLETE_INT		REG_BIT(2)
> +
> +#define _WD_IIR_0			0x6e564
> +#define _WD_IIR_1			0x6ed64
> +#define WD_IIR(tc)			_MMIO_WD(tc,\
> +					_WD_IIR_0,\
> +					_WD_IIR_1)
> +
> +#define _WD_FRAME_STATUS_0		0x6e568
> +#define _WD_FRAME_STATUS_1		0x6ed68
> +#define WD_FRAME_STATUS(tc)		_MMIO_WD(tc,\
> +					_WD_FRAME_STATUS_0,\
> +					_WD_FRAME_STATUS_1)
> +
> +#define WD_FRAME_COMPLETE		REG_BIT(31)
> +#define WD_STATE_MASK			REG_GENMASK(26, 24)
> +#define WD_STATE_IDLE			REG_FIELD_PREP(WD_STATE_MASK, 0)
> +#define WD_STATE_CAPSTART		REG_FIELD_PREP(WD_STATE_MASK, 1)
> +#define WD_STATE_FRAME_START		REG_FIELD_PREP(WD_STATE_MASK, 2)
> +#define WD_STATE_CAPACITIVE		REG_FIELD_PREP(WD_STATE_MASK, 3)
> +#define WD_STATE_TG_DONE		REG_FIELD_PREP(WD_STATE_MASK, 4)
> +#define WD_STATE_WDX_DONE		REG_FIELD_PREP(WD_STATE_MASK, 5)
> +#define WD_STATE_QUICK_CAP		REG_FIELD_PREP(WD_STATE_MASK, 6)
> +
> +#define _WD_27_M_0			0x6e524
> +#define _WD_27_M_1			0x6ed24
> +#define WD_27_M(tc)			_MMIO_WD(tc,\
> +					_WD_27_M_0,\
> +					_WD_27_M_1)
> +
> +#define _WD_27_N_0			0x6e528
> +
> +/* Address looks wrong in bspec: */
> +#define _WD_27_N_1			0x6ec28
> +#define WD_27_N(tc)			_MMIO_WD(tc,\
> +					_WD_27_N_0,\
> +					_WD_27_N_1)
> +
> +#define _WD_TAIL_CFG_0			0x6e520
> +#define _WD_TAIL_CFG_1			0x6ed20
> +
> +#define WD_TAIL_CFG(tc)			_MMIO_WD(tc,\
> +					_WD_TAIL_CFG_0,\
> +					_WD_TAIL_CFG_1)
> +
> +#endif /* __INTEL_WRITEBACK_REGS_H__ */