xref: /openbmc/linux/sound/drivers/vx/vx_uer.c (revision 842ed298)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver for Digigram VX soundcards
4  *
5  * IEC958 stuff
6  *
7  * Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
8  */
9 
10 #include <linux/delay.h>
11 #include <sound/core.h>
12 #include <sound/vx_core.h>
13 #include "vx_cmd.h"
14 
15 
16 /*
17  * vx_modify_board_clock - tell the board that its clock has been modified
18  * @sync: DSP needs to resynchronize its FIFO
19  */
20 static int vx_modify_board_clock(struct vx_core *chip, int sync)
21 {
22 	struct vx_rmh rmh;
23 
24 	vx_init_rmh(&rmh, CMD_MODIFY_CLOCK);
25 	/* Ask the DSP to resynchronize its FIFO. */
26 	if (sync)
27 		rmh.Cmd[0] |= CMD_MODIFY_CLOCK_S_BIT;
28 	return vx_send_msg(chip, &rmh);
29 }
30 
31 /*
32  * vx_modify_board_inputs - resync audio inputs
33  */
34 static int vx_modify_board_inputs(struct vx_core *chip)
35 {
36 	struct vx_rmh rmh;
37 
38 	vx_init_rmh(&rmh, CMD_RESYNC_AUDIO_INPUTS);
39         rmh.Cmd[0] |= 1 << 0; /* reference: AUDIO 0 */
40 	return vx_send_msg(chip, &rmh);
41 }
42 
43 /*
44  * vx_read_one_cbit - read one bit from UER config
45  * @index: the bit index
46  * returns 0 or 1.
47  */
48 static int vx_read_one_cbit(struct vx_core *chip, int index)
49 {
50 	int val;
51 
52 	mutex_lock(&chip->lock);
53 	if (chip->type >= VX_TYPE_VXPOCKET) {
54 		vx_outb(chip, CSUER, 1); /* read */
55 		vx_outb(chip, RUER, index & XX_UER_CBITS_OFFSET_MASK);
56 		val = (vx_inb(chip, RUER) >> 7) & 0x01;
57 	} else {
58 		vx_outl(chip, CSUER, 1); /* read */
59 		vx_outl(chip, RUER, index & XX_UER_CBITS_OFFSET_MASK);
60 		val = (vx_inl(chip, RUER) >> 7) & 0x01;
61 	}
62 	mutex_unlock(&chip->lock);
63 	return val;
64 }
65 
66 /*
67  * vx_write_one_cbit - write one bit to UER config
68  * @index: the bit index
69  * @val: bit value, 0 or 1
70  */
71 static void vx_write_one_cbit(struct vx_core *chip, int index, int val)
72 {
73 	val = !!val;	/* 0 or 1 */
74 	mutex_lock(&chip->lock);
75 	if (vx_is_pcmcia(chip)) {
76 		vx_outb(chip, CSUER, 0); /* write */
77 		vx_outb(chip, RUER, (val << 7) | (index & XX_UER_CBITS_OFFSET_MASK));
78 	} else {
79 		vx_outl(chip, CSUER, 0); /* write */
80 		vx_outl(chip, RUER, (val << 7) | (index & XX_UER_CBITS_OFFSET_MASK));
81 	}
82 	mutex_unlock(&chip->lock);
83 }
84 
85 /*
86  * vx_read_uer_status - read the current UER status
87  * @mode: pointer to store the UER mode, VX_UER_MODE_XXX
88  *
89  * returns the frequency of UER, or 0 if not sync,
90  * or a negative error code.
91  */
92 static int vx_read_uer_status(struct vx_core *chip, unsigned int *mode)
93 {
94 	int val, freq;
95 
96 	/* Default values */
97 	freq = 0;
98 
99 	/* Read UER status */
100 	if (vx_is_pcmcia(chip))
101 	    val = vx_inb(chip, CSUER);
102 	else
103 	    val = vx_inl(chip, CSUER);
104 	if (val < 0)
105 		return val;
106 	/* If clock is present, read frequency */
107 	if (val & VX_SUER_CLOCK_PRESENT_MASK) {
108 		switch (val & VX_SUER_FREQ_MASK) {
109 		case VX_SUER_FREQ_32KHz_MASK:
110 			freq = 32000;
111 			break;
112 		case VX_SUER_FREQ_44KHz_MASK:
113 			freq = 44100;
114 			break;
115 		case VX_SUER_FREQ_48KHz_MASK:
116 			freq = 48000;
117 			break;
118 		}
119         }
120 	if (val & VX_SUER_DATA_PRESENT_MASK)
121 		/* bit 0 corresponds to consumer/professional bit */
122 		*mode = vx_read_one_cbit(chip, 0) ?
123 			VX_UER_MODE_PROFESSIONAL : VX_UER_MODE_CONSUMER;
124 	else
125 		*mode = VX_UER_MODE_NOT_PRESENT;
126 
127 	return freq;
128 }
129 
130 
131 /*
132  * compute the sample clock value from frequency
133  *
134  * The formula is as follows:
135  *
136  *    HexFreq = (dword) ((double) ((double) 28224000 / (double) Frequency))
137  *    switch ( HexFreq & 0x00000F00 )
138  *    case 0x00000100: ;
139  *    case 0x00000200:
140  *    case 0x00000300: HexFreq -= 0x00000201 ;
141  *    case 0x00000400:
142  *    case 0x00000500:
143  *    case 0x00000600:
144  *    case 0x00000700: HexFreq = (dword) (((double) 28224000 / (double) (Frequency*2)) - 1)
145  *    default        : HexFreq = (dword) ((double) 28224000 / (double) (Frequency*4)) - 0x000001FF
146  */
147 
148 static int vx_calc_clock_from_freq(struct vx_core *chip, int freq)
149 {
150 	int hexfreq;
151 
152 	if (snd_BUG_ON(freq <= 0))
153 		return 0;
154 
155 	hexfreq = (28224000 * 10) / freq;
156 	hexfreq = (hexfreq + 5) / 10;
157 
158 	/* max freq = 55125 Hz */
159 	if (snd_BUG_ON(hexfreq <= 0x00000200))
160 		return 0;
161 
162 	if (hexfreq <= 0x03ff)
163 		return hexfreq - 0x00000201;
164 	if (hexfreq <= 0x07ff)
165 		return (hexfreq / 2) - 1;
166 	if (hexfreq <= 0x0fff)
167 		return (hexfreq / 4) + 0x000001ff;
168 
169 	return 0x5fe; 	/* min freq = 6893 Hz */
170 }
171 
172 
173 /*
174  * vx_change_clock_source - change the clock source
175  * @source: the new source
176  */
177 static void vx_change_clock_source(struct vx_core *chip, int source)
178 {
179 	/* we mute DAC to prevent clicks */
180 	vx_toggle_dac_mute(chip, 1);
181 	mutex_lock(&chip->lock);
182 	chip->ops->set_clock_source(chip, source);
183 	chip->clock_source = source;
184 	mutex_unlock(&chip->lock);
185 	/* unmute */
186 	vx_toggle_dac_mute(chip, 0);
187 }
188 
189 
190 /*
191  * set the internal clock
192  */
193 void vx_set_internal_clock(struct vx_core *chip, unsigned int freq)
194 {
195 	int clock;
196 
197 	/* Get real clock value */
198 	clock = vx_calc_clock_from_freq(chip, freq);
199 	snd_printdd(KERN_DEBUG "set internal clock to 0x%x from freq %d\n", clock, freq);
200 	mutex_lock(&chip->lock);
201 	if (vx_is_pcmcia(chip)) {
202 		vx_outb(chip, HIFREQ, (clock >> 8) & 0x0f);
203 		vx_outb(chip, LOFREQ, clock & 0xff);
204 	} else {
205 		vx_outl(chip, HIFREQ, (clock >> 8) & 0x0f);
206 		vx_outl(chip, LOFREQ, clock & 0xff);
207 	}
208 	mutex_unlock(&chip->lock);
209 }
210 
211 
212 /*
213  * set the iec958 status bits
214  * @bits: 32-bit status bits
215  */
216 void vx_set_iec958_status(struct vx_core *chip, unsigned int bits)
217 {
218 	int i;
219 
220 	if (chip->chip_status & VX_STAT_IS_STALE)
221 		return;
222 
223 	for (i = 0; i < 32; i++)
224 		vx_write_one_cbit(chip, i, bits & (1 << i));
225 }
226 
227 
228 /*
229  * vx_set_clock - change the clock and audio source if necessary
230  */
231 int vx_set_clock(struct vx_core *chip, unsigned int freq)
232 {
233 	int src_changed = 0;
234 
235 	if (chip->chip_status & VX_STAT_IS_STALE)
236 		return 0;
237 
238 	/* change the audio source if possible */
239 	vx_sync_audio_source(chip);
240 
241 	if (chip->clock_mode == VX_CLOCK_MODE_EXTERNAL ||
242 	    (chip->clock_mode == VX_CLOCK_MODE_AUTO &&
243 	     chip->audio_source == VX_AUDIO_SRC_DIGITAL)) {
244 		if (chip->clock_source != UER_SYNC) {
245 			vx_change_clock_source(chip, UER_SYNC);
246 			mdelay(6);
247 			src_changed = 1;
248 		}
249 	} else if (chip->clock_mode == VX_CLOCK_MODE_INTERNAL ||
250 		   (chip->clock_mode == VX_CLOCK_MODE_AUTO &&
251 		    chip->audio_source != VX_AUDIO_SRC_DIGITAL)) {
252 		if (chip->clock_source != INTERNAL_QUARTZ) {
253 			vx_change_clock_source(chip, INTERNAL_QUARTZ);
254 			src_changed = 1;
255 		}
256 		if (chip->freq == freq)
257 			return 0;
258 		vx_set_internal_clock(chip, freq);
259 		if (src_changed)
260 			vx_modify_board_inputs(chip);
261 	}
262 	if (chip->freq == freq)
263 		return 0;
264 	chip->freq = freq;
265 	vx_modify_board_clock(chip, 1);
266 	return 0;
267 }
268 
269 
270 /*
271  * vx_change_frequency - called from interrupt handler
272  */
273 int vx_change_frequency(struct vx_core *chip)
274 {
275 	int freq;
276 
277 	if (chip->chip_status & VX_STAT_IS_STALE)
278 		return 0;
279 
280 	if (chip->clock_source == INTERNAL_QUARTZ)
281 		return 0;
282 	/*
283 	 * Read the real UER board frequency
284 	 */
285 	freq = vx_read_uer_status(chip, &chip->uer_detected);
286 	if (freq < 0)
287 		return freq;
288 	/*
289 	 * The frequency computed by the DSP is good and
290 	 * is different from the previous computed.
291 	 */
292 	if (freq == 48000 || freq == 44100 || freq == 32000)
293 		chip->freq_detected = freq;
294 
295 	return 0;
296 }
297