path: root/drivers/gpu/drm/radeon/si.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 "drmP.h"
#include "radeon.h"
#include "radeon_asic.h"
#include "radeon_drm.h"
#include "sid.h"
#include "atom.h"

/* watermark setup */
static u32 dce6_line_buffer_adjust(struct radeon_device *rdev,
				   struct radeon_crtc *radeon_crtc,
				   struct drm_display_mode *mode,
				   struct drm_display_mode *other_mode)
{
	u32 tmp;
	/*
	 * Line Buffer Setup
	 * There are 3 line buffers, each one shared by 2 display controllers.
	 * DC_LB_MEMORY_SPLIT controls how that line buffer is shared between
	 * the display controllers.  The paritioning is done via one of four
	 * preset allocations specified in bits 21:20:
	 *  0 - half lb
	 *  2 - whole lb, other crtc must be disabled
	 */
	/* this can get tricky if we have two large displays on a paired group
	 * of crtcs.  Ideally for multiple large displays we'd assign them to
	 * non-linked crtcs for maximum line buffer allocation.
	 */
	if (radeon_crtc->base.enabled && mode) {
		if (other_mode)
			tmp = 0; /* 1/2 */
		else
			tmp = 2; /* whole */
	} else
		tmp = 0;

	WREG32(DC_LB_MEMORY_SPLIT + radeon_crtc->crtc_offset,
	       DC_LB_MEMORY_CONFIG(tmp));

	if (radeon_crtc->base.enabled && mode) {
		switch (tmp) {
		case 0:
		default:
			return 4096 * 2;
		case 2:
			return 8192 * 2;
		}
	}

	/* controller not enabled, so no lb used */
	return 0;
}

static u32 dce6_get_number_of_dram_channels(struct radeon_device *rdev)
{
	u32 tmp = RREG32(MC_SHARED_CHMAP);

	switch ((tmp & NOOFCHAN_MASK) >> NOOFCHAN_SHIFT) {
	case 0:
	default:
		return 1;
	case 1:
		return 2;
	case 2:
		return 4;
	case 3:
		return 8;
	case 4:
		return 3;
	case 5:
		return 6;
	case 6:
		return 10;
	case 7:
		return 12;
	case 8:
		return 16;
	}
}

struct dce6_wm_params {
	u32 dram_channels; /* number of dram channels */
	u32 yclk;          /* bandwidth per dram data pin in kHz */
	u32 sclk;          /* engine clock in kHz */
	u32 disp_clk;      /* display clock in kHz */
	u32 src_width;     /* viewport width */
	u32 active_time;   /* active display time in ns */
	u32 blank_time;    /* blank time in ns */
	bool interlaced;    /* mode is interlaced */
	fixed20_12 vsc;    /* vertical scale ratio */
	u32 num_heads;     /* number of active crtcs */
	u32 bytes_per_pixel; /* bytes per pixel display + overlay */
	u32 lb_size;       /* line buffer allocated to pipe */
	u32 vtaps;         /* vertical scaler taps */
};

static u32 dce6_dram_bandwidth(struct dce6_wm_params *wm)
{
	/* Calculate raw DRAM Bandwidth */
	fixed20_12 dram_efficiency; /* 0.7 */
	fixed20_12 yclk, dram_channels, bandwidth;
	fixed20_12 a;

	a.full = dfixed_const(1000);
	yclk.full = dfixed_const(wm->yclk);
	yclk.full = dfixed_div(yclk, a);
	dram_channels.full = dfixed_const(wm->dram_channels * 4);
	a.full = dfixed_const(10);
	dram_efficiency.full = dfixed_const(7);
	dram_efficiency.full = dfixed_div(dram_efficiency, a);
	bandwidth.full = dfixed_mul(dram_channels, yclk);
	bandwidth.full = dfixed_mul(bandwidth, dram_efficiency);

	return dfixed_trunc(bandwidth);
}

static u32 dce6_dram_bandwidth_for_display(struct dce6_wm_params *wm)
{
	/* Calculate DRAM Bandwidth and the part allocated to display. */
	fixed20_12 disp_dram_allocation; /* 0.3 to 0.7 */
	fixed20_12 yclk, dram_channels, bandwidth;
	fixed20_12 a;

	a.full = dfixed_const(1000);
	yclk.full = dfixed_const(wm->yclk);
	yclk.full = dfixed_div(yclk, a);
	dram_channels.full = dfixed_const(wm->dram_channels * 4);
	a.full = dfixed_const(10);
	disp_dram_allocation.full = dfixed_const(3); /* XXX worse case value 0.3 */
	disp_dram_allocation.full = dfixed_div(disp_dram_allocation, a);
	bandwidth.full = dfixed_mul(dram_channels, yclk);
	bandwidth.full = dfixed_mul(bandwidth, disp_dram_allocation);

	return dfixed_trunc(bandwidth);
}

static u32 dce6_data_return_bandwidth(struct dce6_wm_params *wm)
{
	/* Calculate the display Data return Bandwidth */
	fixed20_12 return_efficiency; /* 0.8 */
	fixed20_12 sclk, bandwidth;
	fixed20_12 a;

	a.full = dfixed_const(1000);
	sclk.full = dfixed_const(wm->sclk);
	sclk.full = dfixed_div(sclk, a);
	a.full = dfixed_const(10);
	return_efficiency.full = dfixed_const(8);
	return_efficiency.full = dfixed_div(return_efficiency, a);
	a.full = dfixed_const(32);
	bandwidth.full = dfixed_mul(a, sclk);
	bandwidth.full = dfixed_mul(bandwidth, return_efficiency);

	return dfixed_trunc(bandwidth);
}

static u32 dce6_get_dmif_bytes_per_request(struct dce6_wm_params *wm)
{
	return 32;
}

static u32 dce6_dmif_request_bandwidth(struct dce6_wm_params *wm)
{
	/* Calculate the DMIF Request Bandwidth */
	fixed20_12 disp_clk_request_efficiency; /* 0.8 */
	fixed20_12 disp_clk, sclk, bandwidth;
	fixed20_12 a, b1, b2;
	u32 min_bandwidth;

	a.full = dfixed_const(1000);
	disp_clk.full = dfixed_const(wm->disp_clk);
	disp_clk.full = dfixed_div(disp_clk, a);
	a.full = dfixed_const(dce6_get_dmif_bytes_per_request(wm) / 2);
	b1.full = dfixed_mul(a, disp_clk);

	a.full = dfixed_const(1000);
	sclk.full = dfixed_const(wm->sclk);
	sclk.full = dfixed_div(sclk, a);
	a.full = dfixed_const(dce6_get_dmif_bytes_per_request(wm));
	b2.full = dfixed_mul(a, sclk);

	a.full = dfixed_const(10);
	disp_clk_request_efficiency.full = dfixed_const(8);
	disp_clk_request_efficiency.full = dfixed_div(disp_clk_request_efficiency, a);

	min_bandwidth = min(dfixed_trunc(b1), dfixed_trunc(b2));

	a.full = dfixed_const(min_bandwidth);
	bandwidth.full = dfixed_mul(a, disp_clk_request_efficiency);

	return dfixed_trunc(bandwidth);
}

static u32 dce6_available_bandwidth(struct dce6_wm_params *wm)
{
	/* Calculate the Available bandwidth. Display can use this temporarily but not in average. */
	u32 dram_bandwidth = dce6_dram_bandwidth(wm);
	u32 data_return_bandwidth = dce6_data_return_bandwidth(wm);
	u32 dmif_req_bandwidth = dce6_dmif_request_bandwidth(wm);

	return min(dram_bandwidth, min(data_return_bandwidth, dmif_req_bandwidth));
}

static u32 dce6_average_bandwidth(struct dce6_wm_params *wm)
{
	/* Calculate the display mode Average Bandwidth
	 * DisplayMode should contain the source and destination dimensions,
	 * timing, etc.
	 */
	fixed20_12 bpp;
	fixed20_12 line_time;
	fixed20_12 src_width;
	fixed20_12 bandwidth;
	fixed20_12 a;

	a.full = dfixed_const(1000);
	line_time.full = dfixed_const(wm->active_time + wm->blank_time);
	line_time.full = dfixed_div(line_time, a);
	bpp.full = dfixed_const(wm<