[ltp] [PATCH 2/2] Thinkpad Suspend Powersave: Add D2 power saving code for Thinkpads with Radeon video chipsets

[linux-thinkpad@linux-thinkpad.org]

Force the Radeon video chipset on IBM Thinkpads to use the D2 state when
suspending in order to save a much greater amount of power.

This patch is based on an earlier version by Volker Braun, but instead
of using an explicit whitelist that would have to contain hundreds of
entries, instead we enable going to the D2 state for IBM Thinkpads if a
CONFIG_EXPERIMENTAL option (CONFIG_FB_RADEON_THINKPAD_PM) is enabled and
use a black-list if necessary.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Index: src/drivers/video/Kconfig
===================================================================
--- src.orig/drivers/video/Kconfig	2005-03-14 12:40:48.000000000 -0500
+++ src/drivers/video/Kconfig	2005-03-16 00:40:21.000000000 -0500
@@ -711,6 +711,15 @@
 	help
 	  Say Y here if you want DDC/I2C support for your Radeon board. 
 
+config FB_RADEON_THINKPAD_PM
+	bool "Video Power Management for Thinkpads (EXPERIMENTAL)"
+	depends on PM && FB_RADEON && X86 && EXPERIMENTAL
+	default n
+	help
+	  Say Y here if you want to force the Radeon video chipset on 
+	  IBM Thinkpads to use the D2 state when suspending in order to
+	  save a much greater amount of power.
+
 config FB_RADEON_DEBUG
 	bool "Lots of debug output from Radeon driver"
 	depends on FB_RADEON
Index: src/drivers/video/aty/radeon_base.c
===================================================================
--- src.orig/drivers/video/aty/radeon_base.c	2005-03-14 12:40:48.000000000 -0500
+++ src/drivers/video/aty/radeon_base.c	2005-03-14 12:40:48.000000000 -0500
@@ -273,6 +273,9 @@
 #ifdef CONFIG_MTRR
 static int nomtrr = 0;
 #endif
+#ifdef CONFIG_FB_RADEON_THINKPAD_PM
+int radeon_force_sleep = 0;
+#endif
 
 /*
  * prototypes
@@ -2535,6 +2538,10 @@
 			force_measure_pll = 1;
 		} else if (!strncmp(this_opt, "ignore_edid", 11)) {
 			ignore_edid = 1;
+#ifdef CONFIG_FB_RADEON_THINKPAD_PM
+		} else if (!strncmp(this_opt, "force_sleep", 11)) {
+			radeon_force_sleep = 1;
+#endif
 		} else
 			mode_option = this_opt;
 	}
@@ -2574,3 +2581,7 @@
 MODULE_PARM_DESC(panel_yres, "int: set panel yres");
 module_param(mode_option, charp, 0);
 MODULE_PARM_DESC(mode_option, "Specify resolution as \"<xres>x<yres>[-<bpp>][@<refresh>]\" ");
+#ifdef CONFIG_FB_RADEON_THINKPAD_PM
+module_param(radeon_force_sleep, int, 0);
+MODULE_PARM_DESC(radeon_force_sleep, "bool: force ACPI sleep mode on untested machines");
+#endif
Index: src/drivers/video/aty/radeon_pm.c
===================================================================
--- src.orig/drivers/video/aty/radeon_pm.c	2005-03-14 12:40:48.000000000 -0500
+++ src/drivers/video/aty/radeon_pm.c	2005-03-14 12:40:48.000000000 -0500
@@ -27,6 +27,27 @@
 
 #include "ati_ids.h"
 
+#ifdef CONFIG_FB_RADEON_THINKPAD_PM
+#include <linux/dmi.h>
+
+static struct dmi_system_id __devinitdata radeonfb_dmi_table[] = {
+	{
+		.ident = "IBM ThinkPad",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
+			DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad"),
+		},
+	},
+	{ },
+};
+
+static struct dmi_system_id __devinitdata radeonfb_dmi_blacklist[] = {
+	{ },
+};
+
+extern int radeon_force_sleep;
+#endif
+
 void radeon_pm_disable_dynamic_mode(struct radeonfb_info *rinfo)
 {
 	u32 tmp;
@@ -2750,6 +2771,30 @@
 #endif
 	}
 #endif /* defined(CONFIG_PM) && defined(CONFIG_PPC_OF) */
+
+	/* The PM code also seems to work on many IBM ThinkPad models, 
+	 * but of course Your Mileage May Vary.
+	 */
+#ifdef CONFIG_FB_RADEON_THINKPAD_PM
+	if (radeon_force_sleep || 
+	    (rinfo->is_mobility && rinfo->pm_reg &&
+	     (rinfo->family <= CHIP_FAMILY_RV250) &&
+	     dmi_check_system(radeonfb_dmi_table) && 
+	     !dmi_check_system(radeonfb_dmi_blacklist))) {
+		if (radeon_force_sleep)
+			printk("radeonfb: forcefully enabling sleep mode\n");
+		else
+			printk("radeonfb: enabling sleep mode\n");
+
+		rinfo->pm_mode |= radeon_pm_d2;
+
+		/* Power down TV DAC, that saves a significant amount of power,
+		 * we'll have something better once we actually have some TVOut
+		 * support
+		 */
+		OUTREG(TV_DAC_CNTL, INREG(TV_DAC_CNTL) | 0x07000000);
+	}
+#endif /* CONFIG_FB_RADEON_THINKPAD_PM */
 }
 
 void radeonfb_pm_exit(struct radeonfb_info *rinfo)