1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Backlight code for ATI Radeon based graphic cards
4 *
5 * Copyright (c) 2000 Ani Joshi <ajoshi@kernel.crashing.org>
6 * Copyright (c) 2003 Benjamin Herrenschmidt <benh@kernel.crashing.org>
7 * Copyright (c) 2006 Michael Hanselmann <linux-kernel@hansmi.ch>
8 */
9
10#include "radeonfb.h"
11#include <linux/backlight.h>
12#include <linux/slab.h>
13
14#ifdef CONFIG_PMAC_BACKLIGHT
15#include <asm/backlight.h>
16#endif
17
18#define MAX_RADEON_LEVEL 0xFF
19
20struct radeon_bl_privdata {
21	struct radeonfb_info *rinfo;
22	uint8_t negative;
23};
24
25static int radeon_bl_get_level_brightness(struct radeon_bl_privdata *pdata,
26		int level)
27{
28	int rlevel;
29
30	/* Get and convert the value */
31	/* No locking of bl_curve since we read a single value */
32	rlevel = pdata->rinfo->info->bl_curve[level] *
33		 FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL;
34
35	if (rlevel < 0)
36		rlevel = 0;
37	else if (rlevel > MAX_RADEON_LEVEL)
38		rlevel = MAX_RADEON_LEVEL;
39
40	if (pdata->negative)
41		rlevel = MAX_RADEON_LEVEL - rlevel;
42
43	return rlevel;
44}
45
46static int radeon_bl_update_status(struct backlight_device *bd)
47{
48	struct radeon_bl_privdata *pdata = bl_get_data(bd);
49	struct radeonfb_info *rinfo = pdata->rinfo;
50	u32 lvds_gen_cntl, tmpPixclksCntl;
51	int level;
52
53	if (rinfo->mon1_type != MT_LCD)
54		return 0;
55
56	/* We turn off the LCD completely instead of just dimming the
57	 * backlight. This provides some greater power saving and the display
58	 * is useless without backlight anyway.
59	 */
60        if (bd->props.power != FB_BLANK_UNBLANK ||
61	    bd->props.fb_blank != FB_BLANK_UNBLANK)
62		level = 0;
63	else
64		level = bd->props.brightness;
65
66	del_timer_sync(&rinfo->lvds_timer);
67	radeon_engine_idle();
68
69	lvds_gen_cntl = INREG(LVDS_GEN_CNTL);
70	if (level > 0) {
71		lvds_gen_cntl &= ~LVDS_DISPLAY_DIS;
72		if (!(lvds_gen_cntl & LVDS_BLON) || !(lvds_gen_cntl & LVDS_ON)) {
73			lvds_gen_cntl |= (rinfo->init_state.lvds_gen_cntl & LVDS_DIGON);
74			lvds_gen_cntl |= LVDS_BLON | LVDS_EN;
75			OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
76			lvds_gen_cntl &= ~LVDS_BL_MOD_LEVEL_MASK;
77			lvds_gen_cntl |=
78				(radeon_bl_get_level_brightness(pdata, level) <<
79				 LVDS_BL_MOD_LEVEL_SHIFT);
80			lvds_gen_cntl |= LVDS_ON;
81			lvds_gen_cntl |= (rinfo->init_state.lvds_gen_cntl & LVDS_BL_MOD_EN);
82			rinfo->pending_lvds_gen_cntl = lvds_gen_cntl;
83			mod_timer(&rinfo->lvds_timer,
84				  jiffies + msecs_to_jiffies(rinfo->panel_info.pwr_delay));
85		} else {
86			lvds_gen_cntl &= ~LVDS_BL_MOD_LEVEL_MASK;
87			lvds_gen_cntl |=
88				(radeon_bl_get_level_brightness(pdata, level) <<
89				 LVDS_BL_MOD_LEVEL_SHIFT);
90			OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
91		}
92		rinfo->init_state.lvds_gen_cntl &= ~LVDS_STATE_MASK;
93		rinfo->init_state.lvds_gen_cntl |= rinfo->pending_lvds_gen_cntl
94			& LVDS_STATE_MASK;
95	} else {
96		/* Asic bug, when turning off LVDS_ON, we have to make sure
97		   RADEON_PIXCLK_LVDS_ALWAYS_ON bit is off
98		*/
99		tmpPixclksCntl = INPLL(PIXCLKS_CNTL);
100		if (rinfo->is_mobility || rinfo->is_IGP)
101			OUTPLLP(PIXCLKS_CNTL, 0, ~PIXCLK_LVDS_ALWAYS_ONb);
102		lvds_gen_cntl &= ~(LVDS_BL_MOD_LEVEL_MASK | LVDS_BL_MOD_EN);
103		lvds_gen_cntl |= (radeon_bl_get_level_brightness(pdata, 0) <<
104				  LVDS_BL_MOD_LEVEL_SHIFT);
105		lvds_gen_cntl |= LVDS_DISPLAY_DIS;
106		OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
107		udelay(100);
108		lvds_gen_cntl &= ~(LVDS_ON | LVDS_EN);
109		OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
110		lvds_gen_cntl &= ~(LVDS_DIGON);
111		rinfo->pending_lvds_gen_cntl = lvds_gen_cntl;
112		mod_timer(&rinfo->lvds_timer,
113			  jiffies + msecs_to_jiffies(rinfo->panel_info.pwr_delay));
114		if (rinfo->is_mobility || rinfo->is_IGP)
115			OUTPLL(PIXCLKS_CNTL, tmpPixclksCntl);
116	}
117	rinfo->init_state.lvds_gen_cntl &= ~LVDS_STATE_MASK;
118	rinfo->init_state.lvds_gen_cntl |= (lvds_gen_cntl & LVDS_STATE_MASK);
119
120	return 0;
121}
122
123static const struct backlight_ops radeon_bl_data = {
124	.update_status	= radeon_bl_update_status,
125};
126
127void radeonfb_bl_init(struct radeonfb_info *rinfo)
128{
129	struct backlight_properties props;
130	struct backlight_device *bd;
131	struct radeon_bl_privdata *pdata;
132	char name[12];
133
134	if (rinfo->mon1_type != MT_LCD)
135		return;
136
137#ifdef CONFIG_PMAC_BACKLIGHT
138	if (!pmac_has_backlight_type("ati") &&
139	    !pmac_has_backlight_type("mnca"))
140		return;
141#endif
142
143	pdata = kmalloc(sizeof(struct radeon_bl_privdata), GFP_KERNEL);
144	if (!pdata) {
145		printk("radeonfb: Memory allocation failed\n");
146		goto error;
147	}
148
149	snprintf(name, sizeof(name), "radeonbl%d", rinfo->info->node);
150
151	memset(&props, 0, sizeof(struct backlight_properties));
152	props.type = BACKLIGHT_RAW;
153	props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
154	bd = backlight_device_register(name, rinfo->info->dev, pdata,
155				       &radeon_bl_data, &props);
156	if (IS_ERR(bd)) {
157		rinfo->info->bl_dev = NULL;
158		printk("radeonfb: Backlight registration failed\n");
159		goto error;
160	}
161
162	pdata->rinfo = rinfo;
163
164	/* Pardon me for that hack... maybe some day we can figure out in what
165	 * direction backlight should work on a given panel?
166	 */
167	pdata->negative =
168		(rinfo->family != CHIP_FAMILY_RV200 &&
169		 rinfo->family != CHIP_FAMILY_RV250 &&
170		 rinfo->family != CHIP_FAMILY_RV280 &&
171		 rinfo->family != CHIP_FAMILY_RV350);
172
173#ifdef CONFIG_PMAC_BACKLIGHT
174	pdata->negative = pdata->negative ||
175		of_machine_is_compatible("PowerBook4,3") ||
176		of_machine_is_compatible("PowerBook6,3") ||
177		of_machine_is_compatible("PowerBook6,5");
178#endif
179
180	rinfo->info->bl_dev = bd;
181	fb_bl_default_curve(rinfo->info, 0,
182		 63 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL,
183		217 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL);
184
185	bd->props.brightness = bd->props.max_brightness;
186	bd->props.power = FB_BLANK_UNBLANK;
187	backlight_update_status(bd);
188
189	printk("radeonfb: Backlight initialized (%s)\n", name);
190
191	return;
192
193error:
194	kfree(pdata);
195	return;
196}
197
198void radeonfb_bl_exit(struct radeonfb_info *rinfo)
199{
200	struct backlight_device *bd = rinfo->info->bl_dev;
201
202	if (bd) {
203		struct radeon_bl_privdata *pdata;
204
205		pdata = bl_get_data(bd);
206		backlight_device_unregister(bd);
207		kfree(pdata);
208		rinfo->info->bl_dev = NULL;
209
210		printk("radeonfb: Backlight unloaded\n");
211	}
212}
213