[PATCH] Rewritten backlight infrastructure for portable Apple computers

This patch contains a total rewrite of the backlight infrastructure for
portable Apple computers.  Backward compatibility is retained.  A sysfs
interface allows userland to control the brightness with more steps than
before.  Userland is allowed to upload a brightness curve for different
monitors, similar to Mac OS X.

[akpm@osdl.org: add needed exports]
Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 247 insertions, 0 deletions

diff --git a/drivers/video/aty/radeon_backlight.c b/drivers/video/aty/radeon_backlight.c
new file mode 100644
index 000000000000..7de66b855d4e
--- /dev/null
+++ b/drivers/video/aty/radeon_backlight.c
@@ -0,0 +1,247 @@
+/*
+ * Backlight code for ATI Radeon based graphic cards
+ *
+ * Copyright (c) 2000 Ani Joshi <ajoshi@kernel.crashing.org>
+ * Copyright (c) 2003 Benjamin Herrenschmidt <benh@kernel.crashing.org>
+ * Copyright (c) 2006 Michael Hanselmann <linux-kernel@hansmi.ch>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "radeonfb.h"
+#include <linux/backlight.h>
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+#include <asm/backlight.h>
+#endif
+
+#define MAX_RADEON_LEVEL 0xFF
+
+static struct backlight_properties radeon_bl_data;
+
+struct radeon_bl_privdata {
+	struct radeonfb_info *rinfo;
+	uint8_t negative;
+};
+
+static int radeon_bl_get_level_brightness(struct radeon_bl_privdata *pdata,
+		int level)
+{
+	struct fb_info *info = pdata->rinfo->info;
+	int rlevel;
+
+	mutex_lock(&info->bl_mutex);
+
+	/* Get and convert the value */
+	rlevel = pdata->rinfo->info->bl_curve[level] *
+		 FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL;
+
+	mutex_unlock(&info->bl_mutex);
+
+	if (pdata->negative)
+		rlevel = MAX_RADEON_LEVEL - rlevel;
+
+	if (rlevel < 0)
+		rlevel = 0;
+	else if (rlevel > MAX_RADEON_LEVEL)
+		rlevel = MAX_RADEON_LEVEL;
+
+	return rlevel;
+}
+
+static int radeon_bl_update_status(struct backlight_device *bd)
+{
+	struct radeon_bl_privdata *pdata = class_get_devdata(&bd->class_dev);
+	struct radeonfb_info *rinfo = pdata->rinfo;
+	u32 lvds_gen_cntl, tmpPixclksCntl;
+	int level;
+
+	if (rinfo->mon1_type != MT_LCD)
+		return 0;
+
+	/* We turn off the LCD completely instead of just dimming the
+	 * backlight. This provides some greater power saving and the display
+	 * is useless without backlight anyway.
+	 */
+        if (bd->props->power != FB_BLANK_UNBLANK ||
+	    bd->props->fb_blank != FB_BLANK_UNBLANK)
+		level = 0;
+	else
+		level = bd->props->brightness;
+
+	del_timer_sync(&rinfo->lvds_timer);
+	radeon_engine_idle();
+
+	lvds_gen_cntl = INREG(LVDS_GEN_CNTL);
+	if (level > 0) {
+		lvds_gen_cntl &= ~LVDS_DISPLAY_DIS;
+		if (!(lvds_gen_cntl & LVDS_BLON) || !(lvds_gen_cntl & LVDS_ON)) {
+			lvds_gen_cntl |= (rinfo->init_state.lvds_gen_cntl & LVDS_DIGON);
+			lvds_gen_cntl |= LVDS_BLON | LVDS_EN;
+			OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
+			lvds_gen_cntl &= ~LVDS_BL_MOD_LEVEL_MASK;
+			lvds_gen_cntl |=
+				(radeon_bl_get_level_brightness(pdata, level) <<
+				 LVDS_BL_MOD_LEVEL_SHIFT);
+			lvds_gen_cntl |= LVDS_ON;
+			lvds_gen_cntl |= (rinfo->init_state.lvds_gen_cntl & LVDS_BL_MOD_EN);
+			rinfo->pending_lvds_gen_cntl = lvds_gen_cntl;
+			mod_timer(&rinfo->lvds_timer,
+				  jiffies + msecs_to_jiffies(rinfo->panel_info.pwr_delay));
+		} else {
+			lvds_gen_cntl &= ~LVDS_BL_MOD_LEVEL_MASK;
+			lvds_gen_cntl |=
+				(radeon_bl_get_level_brightness(pdata, level) <<
+				 LVDS_BL_MOD_LEVEL_SHIFT);
+			OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
+		}
+		rinfo->init_state.lvds_gen_cntl &= ~LVDS_STATE_MASK;
+		rinfo->init_state.lvds_gen_cntl |= rinfo->pending_lvds_gen_cntl
+			& LVDS_STATE_MASK;
+	} else {
+		/* Asic bug, when turning off LVDS_ON, we have to make sure
+		   RADEON_PIXCLK_LVDS_ALWAYS_ON bit is off
+		*/
+		tmpPixclksCntl = INPLL(PIXCLKS_CNTL);
+		if (rinfo->is_mobility || rinfo->is_IGP)
+			OUTPLLP(PIXCLKS_CNTL, 0, ~PIXCLK_LVDS_ALWAYS_ONb);
+		lvds_gen_cntl &= ~(LVDS_BL_MOD_LEVEL_MASK | LVDS_BL_MOD_EN);
+		lvds_gen_cntl |= (radeon_bl_get_level_brightness(pdata, 0) <<
+				  LVDS_BL_MOD_LEVEL_SHIFT);
+		lvds_gen_cntl |= LVDS_DISPLAY_DIS;
+		OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
+		udelay(100);
+		lvds_gen_cntl &= ~(LVDS_ON | LVDS_EN);
+		OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
+		lvds_gen_cntl &= ~(LVDS_DIGON);
+		rinfo->pending_lvds_gen_cntl = lvds_gen_cntl;
+		mod_timer(&rinfo->lvds_timer,
+			  jiffies + msecs_to_jiffies(rinfo->panel_info.pwr_delay));
+		if (rinfo->is_mobility || rinfo->is_IGP)
+			OUTPLL(PIXCLKS_CNTL, tmpPixclksCntl);
+	}
+	rinfo->init_state.lvds_gen_cntl &= ~LVDS_STATE_MASK;
+	rinfo->init_state.lvds_gen_cntl |= (lvds_gen_cntl & LVDS_STATE_MASK);
+
+	return 0;
+}
+
+static int radeon_bl_get_brightness(struct backlight_device *bd)
+{
+	return bd->props->brightness;
+}
+
+static struct backlight_properties radeon_bl_data = {
+	.owner		= THIS_MODULE,
+	.get_brightness = radeon_bl_get_brightness,
+	.update_status	= radeon_bl_update_status,
+	.max_brightness = (FB_BACKLIGHT_LEVELS - 1),
+};
+
+void radeonfb_bl_init(struct radeonfb_info *rinfo)
+{
+	struct backlight_device *bd;
+	struct radeon_bl_privdata *pdata;
+	char name[12];
+
+	if (rinfo->mon1_type != MT_LCD)
+		return;
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+	if (!pmac_has_backlight_type("ati") &&
+	    !pmac_has_backlight_type("mnca"))
+		return;
+#endif
+
+	pdata = kmalloc(sizeof(struct radeon_bl_privdata), GFP_KERNEL);
+	if (!pdata) {
+		printk("radeonfb: Memory allocation failed\n");
+		goto error;
+	}
+
+	snprintf(name, sizeof(name), "radeonbl%d", rinfo->info->node);
+
+	bd = backlight_device_register(name, pdata, &radeon_bl_data);
+	if (IS_ERR(bd)) {
+		rinfo->info->bl_dev = NULL;
+		printk("radeonfb: Backlight registration failed\n");
+		goto error;
+	}
+
+	pdata->rinfo = rinfo;
+
+	/* Pardon me for that hack... maybe some day we can figure out in what
+	 * direction backlight should work on a given panel?
+	 */
+	pdata->negative =
+		(rinfo->family != CHIP_FAMILY_RV200 &&
+		 rinfo->family != CHIP_FAMILY_RV250 &&
+		 rinfo->family != CHIP_FAMILY_RV280 &&
+		 rinfo->family != CHIP_FAMILY_RV350);
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+	pdata->negative = pdata->negative ||
+		machine_is_compatible("PowerBook4,3") ||
+		machine_is_compatible("PowerBook6,3") ||
+		machine_is_compatible("PowerBook6,5");
+#endif
+
+	mutex_lock(&rinfo->info->bl_mutex);
+	rinfo->info->bl_dev = bd;
+	fb_bl_default_curve(rinfo->info, 0,
+		 63 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL,
+		217 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL);
+	mutex_unlock(&rinfo->info->bl_mutex);
+
+	up(&bd->sem);
+	bd->props->brightness = radeon_bl_data.max_brightness;
+	bd->props->power = FB_BLANK_UNBLANK;
+	bd->props->update_status(bd);
+	down(&bd->sem);
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+	mutex_lock(&pmac_backlight_mutex);
+	if (!pmac_backlight)
+		pmac_backlight = bd;
+	mutex_unlock(&pmac_backlight_mutex);
+#endif
+
+	printk("radeonfb: Backlight initialized (%s)\n", name);
+
+	return;
+
+error:
+	kfree(pdata);
+	return;
+}
+
+void radeonfb_bl_exit(struct radeonfb_info *rinfo)
+{
+#ifdef CONFIG_PMAC_BACKLIGHT
+	mutex_lock(&pmac_backlight_mutex);
+#endif
+
+	mutex_lock(&rinfo->info->bl_mutex);
+	if (rinfo->info->bl_dev) {
+		struct radeon_bl_privdata *pdata;
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+		if (pmac_backlight == rinfo->info->bl_dev)
+			pmac_backlight = NULL;
+#endif
+
+		pdata = class_get_devdata(&rinfo->info->bl_dev->class_dev);
+		backlight_device_unregister(rinfo->info->bl_dev);
+		kfree(pdata);
+		rinfo->info->bl_dev = NULL;
+
+		printk("radeonfb: Backlight unloaded\n");
+	}
+	mutex_unlock(&rinfo->info->bl_mutex);
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+	mutex_unlock(&pmac_backlight_mutex);
+#endif
+}