1/*
2 * Backlight code for ATI Radeon based graphic cards
3 *
4 * Copyright (c) 2000 Ani Joshi <ajoshi@kernel.crashing.org>
5 * Copyright (c) 2003 Benjamin Herrenschmidt <benh@kernel.crashing.org>
6 * Copyright (c) 2006 Michael Hanselmann <linux-kernel@hansmi.ch>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include "radeonfb.h"
14#include <linux/backlight.h>
15
16#ifdef CONFIG_PMAC_BACKLIGHT
17#include <asm/backlight.h>
18#endif
19
20#define MAX_RADEON_LEVEL 0xFF
21
22struct radeon_bl_privdata {
23	struct radeonfb_info *rinfo;
24	uint8_t negative;
25};
26
27static int radeon_bl_get_level_brightness(struct radeon_bl_privdata *pdata,
28		int level)
29{
30	int rlevel;
31
32	/* Get and convert the value */
33	/* No locking of bl_curve since we read a single value */
34	rlevel = pdata->rinfo->info->bl_curve[level] *
35		 FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL;
36
37	if (rlevel < 0)
38		rlevel = 0;
39	else if (rlevel > MAX_RADEON_LEVEL)
40		rlevel = MAX_RADEON_LEVEL;
41
42	if (pdata->negative)
43		rlevel = MAX_RADEON_LEVEL - rlevel;
44
45	return rlevel;
46}
47
48static int radeon_bl_update_status(struct backlight_device *bd)
49{
50	struct radeon_bl_privdata *pdata = class_get_devdata(&bd->class_dev);
51	struct radeonfb_info *rinfo = pdata->rinfo;
52	u32 lvds_gen_cntl, tmpPixclksCntl;
53	int level;
54
55	if (rinfo->mon1_type != MT_LCD)
56		return 0;
57
58	/* We turn off the LCD completely instead of just dimming the
59	 * backlight. This provides some greater power saving and the display
60	 * is useless without backlight anyway.
61	 */
62        if (bd->props.power != FB_BLANK_UNBLANK ||
63	    bd->props.fb_blank != FB_BLANK_UNBLANK)
64		level = 0;
65	else
66		level = bd->props.brightness;
67
68	del_timer_sync(&rinfo->lvds_timer);
69	radeon_engine_idle();
70
71	lvds_gen_cntl = INREG(LVDS_GEN_CNTL);
72	if (level > 0) {
73		lvds_gen_cntl &= ~LVDS_DISPLAY_DIS;
74		if (!(lvds_gen_cntl & LVDS_BLON) || !(lvds_gen_cntl & LVDS_ON)) {
75			lvds_gen_cntl |= (rinfo->init_state.lvds_gen_cntl & LVDS_DIGON);
76			lvds_gen_cntl |= LVDS_BLON | LVDS_EN;
77			OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
78			lvds_gen_cntl &= ~LVDS_BL_MOD_LEVEL_MASK;
79			lvds_gen_cntl |=
80				(radeon_bl_get_level_brightness(pdata, level) <<
81				 LVDS_BL_MOD_LEVEL_SHIFT);
82			lvds_gen_cntl |= LVDS_ON;
83			lvds_gen_cntl |= (rinfo->init_state.lvds_gen_cntl & LVDS_BL_MOD_EN);
84			rinfo->pending_lvds_gen_cntl = lvds_gen_cntl;
85			mod_timer(&rinfo->lvds_timer,
86				  jiffies + msecs_to_jiffies(rinfo->panel_info.pwr_delay));
87		} else {
88			lvds_gen_cntl &= ~LVDS_BL_MOD_LEVEL_MASK;
89			lvds_gen_cntl |=
90				(radeon_bl_get_level_brightness(pdata, level) <<
91				 LVDS_BL_MOD_LEVEL_SHIFT);
92			OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
93		}
94		rinfo->init_state.lvds_gen_cntl &= ~LVDS_STATE_MASK;
95		rinfo->init_state.lvds_gen_cntl |= rinfo->pending_lvds_gen_cntl
96			& LVDS_STATE_MASK;
97	} else {
98		/* Asic bug, when turning off LVDS_ON, we have to make sure
99		   RADEON_PIXCLK_LVDS_ALWAYS_ON bit is off
100		*/
101		tmpPixclksCntl = INPLL(PIXCLKS_CNTL);
102		if (rinfo->is_mobility || rinfo->is_IGP)
103			OUTPLLP(PIXCLKS_CNTL, 0, ~PIXCLK_LVDS_ALWAYS_ONb);
104		lvds_gen_cntl &= ~(LVDS_BL_MOD_LEVEL_MASK | LVDS_BL_MOD_EN);
105		lvds_gen_cntl |= (radeon_bl_get_level_brightness(pdata, 0) <<
106				  LVDS_BL_MOD_LEVEL_SHIFT);
107		lvds_gen_cntl |= LVDS_DISPLAY_DIS;
108		OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
109		udelay(100);
110		lvds_gen_cntl &= ~(LVDS_ON | LVDS_EN);
111		OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
112		lvds_gen_cntl &= ~(LVDS_DIGON);
113		rinfo->pending_lvds_gen_cntl = lvds_gen_cntl;
114		mod_timer(&rinfo->lvds_timer,
115			  jiffies + msecs_to_jiffies(rinfo->panel_info.pwr_delay));
116		if (rinfo->is_mobility || rinfo->is_IGP)
117			OUTPLL(PIXCLKS_CNTL, tmpPixclksCntl);
118	}
119	rinfo->init_state.lvds_gen_cntl &= ~LVDS_STATE_MASK;
120	rinfo->init_state.lvds_gen_cntl |= (lvds_gen_cntl & LVDS_STATE_MASK);
121
122	return 0;
123}
124
125static int radeon_bl_get_brightness(struct backlight_device *bd)
126{
127	return bd->props.brightness;
128}
129
130static struct backlight_ops radeon_bl_data = {
131	.get_brightness = radeon_bl_get_brightness,
132	.update_status	= radeon_bl_update_status,
133};
134
135void radeonfb_bl_init(struct radeonfb_info *rinfo)
136{
137	struct backlight_device *bd;
138	struct radeon_bl_privdata *pdata;
139	char name[12];
140
141	if (rinfo->mon1_type != MT_LCD)
142		return;
143
144#ifdef CONFIG_PMAC_BACKLIGHT
145	if (!pmac_has_backlight_type("ati") &&
146	    !pmac_has_backlight_type("mnca"))
147		return;
148#endif
149
150	pdata = kmalloc(sizeof(struct radeon_bl_privdata), GFP_KERNEL);
151	if (!pdata) {
152		printk("radeonfb: Memory allocation failed\n");
153		goto error;
154	}
155
156	snprintf(name, sizeof(name), "radeonbl%d", rinfo->info->node);
157
158	bd = backlight_device_register(name, rinfo->info->dev, pdata, &radeon_bl_data);
159	if (IS_ERR(bd)) {
160		rinfo->info->bl_dev = NULL;
161		printk("radeonfb: Backlight registration failed\n");
162		goto error;
163	}
164
165	pdata->rinfo = rinfo;
166
167	/* Pardon me for that hack... maybe some day we can figure out in what
168	 * direction backlight should work on a given panel?
169	 */
170	pdata->negative =
171		(rinfo->family != CHIP_FAMILY_RV200 &&
172		 rinfo->family != CHIP_FAMILY_RV250 &&
173		 rinfo->family != CHIP_FAMILY_RV280 &&
174		 rinfo->family != CHIP_FAMILY_RV350);
175
176#ifdef CONFIG_PMAC_BACKLIGHT
177	pdata->negative = pdata->negative ||
178		machine_is_compatible("PowerBook4,3") ||
179		machine_is_compatible("PowerBook6,3") ||
180		machine_is_compatible("PowerBook6,5");
181#endif
182
183	rinfo->info->bl_dev = bd;
184	fb_bl_default_curve(rinfo->info, 0,
185		 63 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL,
186		217 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL);
187
188	bd->props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
189	bd->props.brightness = bd->props.max_brightness;
190	bd->props.power = FB_BLANK_UNBLANK;
191	backlight_update_status(bd);
192
193	printk("radeonfb: Backlight initialized (%s)\n", name);
194
195	return;
196
197error:
198	kfree(pdata);
199	return;
200}
201
202void radeonfb_bl_exit(struct radeonfb_info *rinfo)
203{
204	struct backlight_device *bd = rinfo->info->bl_dev;
205
206	if (bd) {
207		struct radeon_bl_privdata *pdata;
208
209		pdata = class_get_devdata(&bd->class_dev);
210		backlight_device_unregister(bd);
211		kfree(pdata);
212		rinfo->info->bl_dev = NULL;
213
214		printk("radeonfb: Backlight unloaded\n");
215	}
216}
217