radeon_backlight.c

  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	level = backlight_get_brightness(bd);
 61
 62	timer_delete_sync(&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(&rinfo->lvds_timer,
 80				  jiffies + msecs_to_jiffies(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, 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(&rinfo->lvds_timer,
109			  jiffies + msecs_to_jiffies(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(sizeof(struct radeon_bl_privdata), GFP_KERNEL);
140	if (!pdata) {
141		printk("radeonfb: Memory allocation failed\n");
142		goto error;
143	}
144
145	snprintf(name, sizeof(name), "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, rinfo->info->device, pdata,
151				       &radeon_bl_data, &props);
152	if (IS_ERR(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(rinfo->info, 0,
178		 63 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL,
179		217 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL);
180
181	bd->props.brightness = bd->props.max_brightness;
182	bd->props.power = BACKLIGHT_POWER_ON;
183	backlight_update_status(bd);
184
185	printk("radeonfb: Backlight initialized (%s)\n", name);
186
187	return;
188
189error:
190	kfree(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(bd);
202		backlight_device_unregister(bd);
203		kfree(pdata);
204		rinfo->info->bl_dev = NULL;
205
206		printk("radeonfb: Backlight unloaded\n");
207	}
208}