gxfb: add power management functionality

This adds the ability to suspend/resume the gxfb driver, which includes:
  - The addition of a Graphics Processor register table in gxfb.h, and
    associated GP handling.
  - Register and palette saving code; registers are stored in gxfb_par.
    A few MSR values are saved as well.
  - gx_powerup and gx_powerdown functions which restore/save registers and
    enable/disable graphic engines.
  - gxfb_suspend/gxfb_resume

Originally based on a patch by Jordan Crouse.

Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: Jordan Crouse <jordan.crouse@amd.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 267 insertions, 0 deletions

diff --git a/drivers/video/geode/suspend_gx.c b/drivers/video/geode/suspend_gx.c
new file mode 100644
index 000000000000..9aff32ef8bb6
--- /dev/null
+++ b/drivers/video/geode/suspend_gx.c
@@ -0,0 +1,267 @@
+/*
+ *   Copyright (C) 2007 Advanced Micro Devices, Inc.
+ *   Copyright (C) 2008 Andres Salomon <dilinger@debian.org>
+ *
+ *   This program is free software; you can redistribute it and/or modify it
+ *   under the terms of the GNU General Public License as published by the
+ *   Free Software Foundation; either version 2 of the License, or (at your
+ *   option) any later version.
+ */
+#include <linux/fb.h>
+#include <asm/io.h>
+#include <asm/msr.h>
+#include <asm/geode.h>
+#include <asm/delay.h>
+
+#include "gxfb.h"
+
+#ifdef CONFIG_PM
+
+static void gx_save_regs(struct gxfb_par *par)
+{
+	int i;
+
+	/* wait for the BLT engine to stop being busy */
+	do {
+		i = read_gp(par, GP_BLT_STATUS);
+	} while (i & (GP_BLT_STATUS_BLT_PENDING | GP_BLT_STATUS_BLT_BUSY));
+
+	/* save MSRs */
+	rdmsrl(MSR_GX_MSR_PADSEL, par->msr.padsel);
+	rdmsrl(MSR_GLCP_DOTPLL, par->msr.dotpll);
+
+	write_dc(par, DC_UNLOCK, DC_UNLOCK_UNLOCK);
+
+	/* save registers */
+	memcpy(par->gp, par->gp_regs, sizeof(par->gp));
+	memcpy(par->dc, par->dc_regs, sizeof(par->dc));
+	memcpy(par->vp, par->vid_regs, sizeof(par->vp));
+	memcpy(par->fp, par->vid_regs + VP_FP_START, sizeof(par->fp));
+
+	/* save the palette */
+	write_dc(par, DC_PAL_ADDRESS, 0);
+	for (i = 0; i < ARRAY_SIZE(par->pal); i++)
+		par->pal[i] = read_dc(par, DC_PAL_DATA);
+}
+
+static void gx_set_dotpll(uint32_t dotpll_hi)
+{
+	uint32_t dotpll_lo;
+	int i;
+
+	rdmsrl(MSR_GLCP_DOTPLL, dotpll_lo);
+	dotpll_lo |= MSR_GLCP_DOTPLL_DOTRESET;
+	dotpll_lo &= ~MSR_GLCP_DOTPLL_BYPASS;
+	wrmsr(MSR_GLCP_DOTPLL, dotpll_lo, dotpll_hi);
+
+	/* wait for the PLL to lock */
+	for (i = 0; i < 200; i++) {
+		rdmsrl(MSR_GLCP_DOTPLL, dotpll_lo);
+		if (dotpll_lo & MSR_GLCP_DOTPLL_LOCK)
+			break;
+		udelay(1);
+	}
+
+	/* PLL set, unlock */
+	dotpll_lo &= ~MSR_GLCP_DOTPLL_DOTRESET;
+	wrmsr(MSR_GLCP_DOTPLL, dotpll_lo, dotpll_hi);
+}
+
+static void gx_restore_gfx_proc(struct gxfb_par *par)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(par->gp); i++) {
+		switch (i) {
+		case GP_VECTOR_MODE:
+		case GP_BLT_MODE:
+		case GP_BLT_STATUS:
+		case GP_HST_SRC:
+			/* don't restore these registers */
+			break;
+		default:
+			write_gp(par, i, par->gp[i]);
+		}
+	}
+}
+
+static void gx_restore_display_ctlr(struct gxfb_par *par)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(par->dc); i++) {
+		switch (i) {
+		case DC_UNLOCK:
+			/* unlock the DC; runs first */
+			write_dc(par, DC_UNLOCK, DC_UNLOCK_UNLOCK);
+			break;
+
+		case DC_GENERAL_CFG:
+			/* write without the enables */
+			write_dc(par, i, par->dc[i] & ~(DC_GENERAL_CFG_VIDE |
+					DC_GENERAL_CFG_ICNE |
+					DC_GENERAL_CFG_CURE |
+					DC_GENERAL_CFG_DFLE));
+			break;
+
+		case DC_DISPLAY_CFG:
+			/* write without the enables */
+			write_dc(par, i, par->dc[i] & ~(DC_DISPLAY_CFG_VDEN |
+					DC_DISPLAY_CFG_GDEN |
+					DC_DISPLAY_CFG_TGEN));
+			break;
+
+		case DC_RSVD_0:
+		case DC_RSVD_1:
+		case DC_RSVD_2:
+		case DC_RSVD_3:
+		case DC_RSVD_4:
+		case DC_LINE_CNT:
+		case DC_PAL_ADDRESS:
+		case DC_PAL_DATA:
+		case DC_DFIFO_DIAG:
+		case DC_CFIFO_DIAG:
+		case DC_RSVD_5:
+			/* don't restore these registers */
+			break;
+		default:
+			write_dc(par, i, par->dc[i]);
+		}
+	}
+
+	/* restore the palette */
+	write_dc(par, DC_PAL_ADDRESS, 0);
+	for (i = 0; i < ARRAY_SIZE(par->pal); i++)
+		write_dc(par, DC_PAL_DATA, par->pal[i]);
+}
+
+static void gx_restore_video_proc(struct gxfb_par *par)
+{
+	int i;
+
+	wrmsrl(MSR_GX_MSR_PADSEL, par->msr.padsel);
+
+	for (i = 0; i < ARRAY_SIZE(par->vp); i++) {
+		switch (i) {
+		case VP_VCFG:
+			/* don't enable video yet */
+			write_vp(par, i, par->vp[i] & ~VP_VCFG_VID_EN);
+			break;
+
+		case VP_DCFG:
+			/* don't enable CRT yet */
+			write_vp(par, i, par->vp[i] &
+					~(VP_DCFG_DAC_BL_EN | VP_DCFG_VSYNC_EN |
+					VP_DCFG_HSYNC_EN | VP_DCFG_CRT_EN));
+			break;
+
+		case VP_GAR:
+		case VP_GDR:
+		case VP_RSVD_0:
+		case VP_RSVD_1:
+		case VP_RSVD_2:
+		case VP_RSVD_3:
+		case VP_CRC32:
+		case VP_AWT:
+		case VP_VTM:
+			/* don't restore these registers */
+			break;
+		default:
+			write_vp(par, i, par->vp[i]);
+		}
+	}
+}
+
+static void gx_restore_regs(struct gxfb_par *par)
+{
+	int i;
+
+	gx_set_dotpll((uint32_t) (par->msr.dotpll >> 32));
+	gx_restore_gfx_proc(par);
+	gx_restore_display_ctlr(par);
+	gx_restore_video_proc(par);
+
+	/* Flat Panel */
+	for (i = 0; i < ARRAY_SIZE(par->fp); i++) {
+		if (i != FP_PM && i != FP_RSVD_0)
+			write_fp(par, i, par->fp[i]);
+	}
+}
+
+static void gx_disable_graphics(struct gxfb_par *par)
+{
+	/* shut down the engine */
+	write_vp(par, VP_VCFG, par->vp[VP_VCFG] & ~VP_VCFG_VID_EN);
+	write_vp(par, VP_DCFG, par->vp[VP_DCFG] & ~(VP_DCFG_DAC_BL_EN |
+			VP_DCFG_VSYNC_EN | VP_DCFG_HSYNC_EN | VP_DCFG_CRT_EN));
+
+	/* turn off the flat panel */
+	write_fp(par, FP_PM, par->fp[FP_PM] & ~FP_PM_P);
+
+
+	/* turn off display */
+	write_dc(par, DC_UNLOCK, DC_UNLOCK_UNLOCK);
+	write_dc(par, DC_GENERAL_CFG, par->dc[DC_GENERAL_CFG] &
+			~(DC_GENERAL_CFG_VIDE | DC_GENERAL_CFG_ICNE |
+			DC_GENERAL_CFG_CURE | DC_GENERAL_CFG_DFLE));
+	write_dc(par, DC_DISPLAY_CFG, par->dc[DC_DISPLAY_CFG] &
+			~(DC_DISPLAY_CFG_VDEN | DC_DISPLAY_CFG_GDEN |
+			DC_DISPLAY_CFG_TGEN));
+	write_dc(par, DC_UNLOCK, DC_UNLOCK_LOCK);
+}
+
+static void gx_enable_graphics(struct gxfb_par *par)
+{
+	uint32_t fp;
+
+	fp = read_fp(par, FP_PM);
+	if (par->fp[FP_PM] & FP_PM_P) {
+		/* power on the panel if not already power{ed,ing} on */
+		if (!(fp & (FP_PM_PANEL_ON|FP_PM_PANEL_PWR_UP)))
+			write_fp(par, FP_PM, par->fp[FP_PM]);
+	} else {
+		/* power down the panel if not already power{ed,ing} down */
+		if (!(fp & (FP_PM_PANEL_OFF|FP_PM_PANEL_PWR_DOWN)))
+			write_fp(par, FP_PM, par->fp[FP_PM]);
+	}
+
+	/* turn everything on */
+	write_vp(par, VP_VCFG, par->vp[VP_VCFG]);
+	write_vp(par, VP_DCFG, par->vp[VP_DCFG]);
+	write_dc(par, DC_DISPLAY_CFG, par->dc[DC_DISPLAY_CFG]);
+	/* do this last; it will enable the FIFO load */
+	write_dc(par, DC_GENERAL_CFG, par->dc[DC_GENERAL_CFG]);
+
+	/* lock the door behind us */
+	write_dc(par, DC_UNLOCK, DC_UNLOCK_LOCK);
+}
+
+int gx_powerdown(struct fb_info *info)
+{
+	struct gxfb_par *par = info->par;
+
+	if (par->powered_down)
+		return 0;
+
+	gx_save_regs(par);
+	gx_disable_graphics(par);
+
+	par->powered_down = 1;
+	return 0;
+}
+
+int gx_powerup(struct fb_info *info)
+{
+	struct gxfb_par *par = info->par;
+
+	if (!par->powered_down)
+		return 0;
+
+	gx_restore_regs(par);
+	gx_enable_graphics(par);
+
+	par->powered_down  = 0;
+	return 0;
+}
+
+#endif