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(bl_dev: 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 level = backlight_get_brightness(bd);
61
62 del_timer_sync(timer: &rinfo->lvds_timer);
63 radeon_engine_idle();
64
65 lvds_gen_cntl = INREG(LVDS_GEN_CNTL);
66 if (level > 0) {
67 lvds_gen_cntl &= ~LVDS_DISPLAY_DIS;
68 if (!(lvds_gen_cntl & LVDS_BLON) || !(lvds_gen_cntl & LVDS_ON)) {
69 lvds_gen_cntl |= (rinfo->init_state.lvds_gen_cntl & LVDS_DIGON);
70 lvds_gen_cntl |= LVDS_BLON | LVDS_EN;
71 OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
72 lvds_gen_cntl &= ~LVDS_BL_MOD_LEVEL_MASK;
73 lvds_gen_cntl |=
74 (radeon_bl_get_level_brightness(pdata, level) <<
75 LVDS_BL_MOD_LEVEL_SHIFT);
76 lvds_gen_cntl |= LVDS_ON;
77 lvds_gen_cntl |= (rinfo->init_state.lvds_gen_cntl & LVDS_BL_MOD_EN);
78 rinfo->pending_lvds_gen_cntl = lvds_gen_cntl;
79 mod_timer(timer: &rinfo->lvds_timer,
80 expires: jiffies + msecs_to_jiffies(m: rinfo->panel_info.pwr_delay));
81 } else {
82 lvds_gen_cntl &= ~LVDS_BL_MOD_LEVEL_MASK;
83 lvds_gen_cntl |=
84 (radeon_bl_get_level_brightness(pdata, level) <<
85 LVDS_BL_MOD_LEVEL_SHIFT);
86 OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
87 }
88 rinfo->init_state.lvds_gen_cntl &= ~LVDS_STATE_MASK;
89 rinfo->init_state.lvds_gen_cntl |= rinfo->pending_lvds_gen_cntl
90 & LVDS_STATE_MASK;
91 } else {
92 /* Asic bug, when turning off LVDS_ON, we have to make sure
93 RADEON_PIXCLK_LVDS_ALWAYS_ON bit is off
94 */
95 tmpPixclksCntl = INPLL(PIXCLKS_CNTL);
96 if (rinfo->is_mobility || rinfo->is_IGP)
97 OUTPLLP(PIXCLKS_CNTL, 0, ~PIXCLK_LVDS_ALWAYS_ONb);
98 lvds_gen_cntl &= ~(LVDS_BL_MOD_LEVEL_MASK | LVDS_BL_MOD_EN);
99 lvds_gen_cntl |= (radeon_bl_get_level_brightness(pdata, level: 0) <<
100 LVDS_BL_MOD_LEVEL_SHIFT);
101 lvds_gen_cntl |= LVDS_DISPLAY_DIS;
102 OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
103 udelay(100);
104 lvds_gen_cntl &= ~(LVDS_ON | LVDS_EN);
105 OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
106 lvds_gen_cntl &= ~(LVDS_DIGON);
107 rinfo->pending_lvds_gen_cntl = lvds_gen_cntl;
108 mod_timer(timer: &rinfo->lvds_timer,
109 expires: jiffies + msecs_to_jiffies(m: rinfo->panel_info.pwr_delay));
110 if (rinfo->is_mobility || rinfo->is_IGP)
111 OUTPLL(PIXCLKS_CNTL, tmpPixclksCntl);
112 }
113 rinfo->init_state.lvds_gen_cntl &= ~LVDS_STATE_MASK;
114 rinfo->init_state.lvds_gen_cntl |= (lvds_gen_cntl & LVDS_STATE_MASK);
115
116 return 0;
117}
118
119static const struct backlight_ops radeon_bl_data = {
120 .update_status = radeon_bl_update_status,
121};
122
123void radeonfb_bl_init(struct radeonfb_info *rinfo)
124{
125 struct backlight_properties props;
126 struct backlight_device *bd;
127 struct radeon_bl_privdata *pdata;
128 char name[12];
129
130 if (rinfo->mon1_type != MT_LCD)
131 return;
132
133#ifdef CONFIG_PMAC_BACKLIGHT
134 if (!pmac_has_backlight_type("ati") &&
135 !pmac_has_backlight_type("mnca"))
136 return;
137#endif
138
139 pdata = kmalloc(size: sizeof(struct radeon_bl_privdata), GFP_KERNEL);
140 if (!pdata) {
141 printk("radeonfb: Memory allocation failed\n");
142 goto error;
143 }
144
145 snprintf(buf: name, size: sizeof(name), fmt: "radeonbl%d", rinfo->info->node);
146
147 memset(&props, 0, sizeof(struct backlight_properties));
148 props.type = BACKLIGHT_RAW;
149 props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
150 bd = backlight_device_register(name, dev: rinfo->info->device, devdata: pdata,
151 ops: &radeon_bl_data, props: &props);
152 if (IS_ERR(ptr: bd)) {
153 rinfo->info->bl_dev = NULL;
154 printk("radeonfb: Backlight registration failed\n");
155 goto error;
156 }
157
158 pdata->rinfo = rinfo;
159
160 /* Pardon me for that hack... maybe some day we can figure out in what
161 * direction backlight should work on a given panel?
162 */
163 pdata->negative =
164 (rinfo->family != CHIP_FAMILY_RV200 &&
165 rinfo->family != CHIP_FAMILY_RV250 &&
166 rinfo->family != CHIP_FAMILY_RV280 &&
167 rinfo->family != CHIP_FAMILY_RV350);
168
169#ifdef CONFIG_PMAC_BACKLIGHT
170 pdata->negative = pdata->negative ||
171 of_machine_is_compatible("PowerBook4,3") ||
172 of_machine_is_compatible("PowerBook6,3") ||
173 of_machine_is_compatible("PowerBook6,5");
174#endif
175
176 rinfo->info->bl_dev = bd;
177 fb_bl_default_curve(fb_info: rinfo->info, off: 0,
178 min: 63 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL,
179 max: 217 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL);
180
181 bd->props.brightness = bd->props.max_brightness;
182 bd->props.power = FB_BLANK_UNBLANK;
183 backlight_update_status(bd);
184
185 printk("radeonfb: Backlight initialized (%s)\n", name);
186
187 return;
188
189error:
190 kfree(objp: pdata);
191 return;
192}
193
194void radeonfb_bl_exit(struct radeonfb_info *rinfo)
195{
196 struct backlight_device *bd = rinfo->info->bl_dev;
197
198 if (bd) {
199 struct radeon_bl_privdata *pdata;
200
201 pdata = bl_get_data(bl_dev: bd);
202 backlight_device_unregister(bd);
203 kfree(objp: pdata);
204 rinfo->info->bl_dev = NULL;
205
206 printk("radeonfb: Backlight unloaded\n");
207 }
208}
209

source code of linux/drivers/video/fbdev/aty/radeon_backlight.c