xref: /openbmc/linux/sound/soc/sh/rcar/adg.c (revision 8a10bc9d)
1 /*
2  * Helper routines for R-Car sound ADG.
3  *
4  *  Copyright (C) 2013  Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file "COPYING" in the main directory of this archive
8  * for more details.
9  */
10 #include <linux/sh_clk.h>
11 #include "rsnd.h"
12 
13 #define CLKA	0
14 #define CLKB	1
15 #define CLKC	2
16 #define CLKI	3
17 #define CLKMAX	4
18 
19 struct rsnd_adg {
20 	struct clk *clk[CLKMAX];
21 
22 	int rbga_rate_for_441khz_div_6;	/* RBGA */
23 	int rbgb_rate_for_48khz_div_6;	/* RBGB */
24 	u32 ckr;
25 };
26 
27 #define for_each_rsnd_clk(pos, adg, i)		\
28 	for (i = 0, (pos) = adg->clk[i];	\
29 	     i < CLKMAX;			\
30 	     i++, (pos) = adg->clk[i])
31 #define rsnd_priv_to_adg(priv) ((struct rsnd_adg *)(priv)->adg)
32 
33 static int rsnd_adg_set_convert_clk_gen1(struct rsnd_priv *priv,
34 					 struct rsnd_mod *mod,
35 					 unsigned int src_rate,
36 					 unsigned int dst_rate)
37 {
38 	struct rsnd_adg *adg = rsnd_priv_to_adg(priv);
39 	struct device *dev = rsnd_priv_to_dev(priv);
40 	int idx, sel, div, shift;
41 	u32 mask, val;
42 	int id = rsnd_mod_id(mod);
43 	unsigned int sel_rate [] = {
44 		clk_get_rate(adg->clk[CLKA]),	/* 000: CLKA */
45 		clk_get_rate(adg->clk[CLKB]),	/* 001: CLKB */
46 		clk_get_rate(adg->clk[CLKC]),	/* 010: CLKC */
47 		0,				/* 011: MLBCLK (not used) */
48 		adg->rbga_rate_for_441khz_div_6,/* 100: RBGA */
49 		adg->rbgb_rate_for_48khz_div_6,	/* 101: RBGB */
50 	};
51 
52 	/* find div (= 1/128, 1/256, 1/512, 1/1024, 1/2048 */
53 	for (sel = 0; sel < ARRAY_SIZE(sel_rate); sel++) {
54 		for (div  = 128,	idx = 0;
55 		     div <= 2048;
56 		     div *= 2,		idx++) {
57 			if (src_rate == sel_rate[sel] / div) {
58 				val = (idx << 4) | sel;
59 				goto find_rate;
60 			}
61 		}
62 	}
63 	dev_err(dev, "can't find convert src clk\n");
64 	return -EINVAL;
65 
66 find_rate:
67 	shift	= (id % 4) * 8;
68 	mask	= 0xFF << shift;
69 	val	= val << shift;
70 
71 	dev_dbg(dev, "adg convert src clk = %02x\n", val);
72 
73 	switch (id / 4) {
74 	case 0:
75 		rsnd_mod_bset(mod, AUDIO_CLK_SEL3, mask, val);
76 		break;
77 	case 1:
78 		rsnd_mod_bset(mod, AUDIO_CLK_SEL4, mask, val);
79 		break;
80 	case 2:
81 		rsnd_mod_bset(mod, AUDIO_CLK_SEL5, mask, val);
82 		break;
83 	}
84 
85 	/*
86 	 * Gen1 doesn't need dst_rate settings,
87 	 * since it uses SSI WS pin.
88 	 * see also rsnd_src_set_route_if_gen1()
89 	 */
90 
91 	return 0;
92 }
93 
94 int rsnd_adg_set_convert_clk(struct rsnd_priv *priv,
95 			     struct rsnd_mod *mod,
96 			     unsigned int src_rate,
97 			     unsigned int dst_rate)
98 {
99 	if (rsnd_is_gen1(priv))
100 		return rsnd_adg_set_convert_clk_gen1(priv, mod,
101 						     src_rate, dst_rate);
102 
103 	return -EINVAL;
104 }
105 
106 static void rsnd_adg_set_ssi_clk(struct rsnd_mod *mod, u32 val)
107 {
108 	int id = rsnd_mod_id(mod);
109 	int shift = (id % 4) * 8;
110 	u32 mask = 0xFF << shift;
111 
112 	val = val << shift;
113 
114 	/*
115 	 * SSI 8 is not connected to ADG.
116 	 * it works with SSI 7
117 	 */
118 	if (id == 8)
119 		return;
120 
121 	switch (id / 4) {
122 	case 0:
123 		rsnd_mod_bset(mod, AUDIO_CLK_SEL0, mask, val);
124 		break;
125 	case 1:
126 		rsnd_mod_bset(mod, AUDIO_CLK_SEL1, mask, val);
127 		break;
128 	case 2:
129 		rsnd_mod_bset(mod, AUDIO_CLK_SEL2, mask, val);
130 		break;
131 	}
132 }
133 
134 int rsnd_adg_ssi_clk_stop(struct rsnd_mod *mod)
135 {
136 	/*
137 	 * "mod" = "ssi" here.
138 	 * we can get "ssi id" from mod
139 	 */
140 	rsnd_adg_set_ssi_clk(mod, 0);
141 
142 	return 0;
143 }
144 
145 int rsnd_adg_ssi_clk_try_start(struct rsnd_mod *mod, unsigned int rate)
146 {
147 	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
148 	struct rsnd_adg *adg = rsnd_priv_to_adg(priv);
149 	struct device *dev = rsnd_priv_to_dev(priv);
150 	struct clk *clk;
151 	int i;
152 	u32 data;
153 	int sel_table[] = {
154 		[CLKA] = 0x1,
155 		[CLKB] = 0x2,
156 		[CLKC] = 0x3,
157 		[CLKI] = 0x0,
158 	};
159 
160 	dev_dbg(dev, "request clock = %d\n", rate);
161 
162 	/*
163 	 * find suitable clock from
164 	 * AUDIO_CLKA/AUDIO_CLKB/AUDIO_CLKC/AUDIO_CLKI.
165 	 */
166 	data = 0;
167 	for_each_rsnd_clk(clk, adg, i) {
168 		if (rate == clk_get_rate(clk)) {
169 			data = sel_table[i];
170 			goto found_clock;
171 		}
172 	}
173 
174 	/*
175 	 * find 1/6 clock from BRGA/BRGB
176 	 */
177 	if (rate == adg->rbga_rate_for_441khz_div_6) {
178 		data = 0x10;
179 		goto found_clock;
180 	}
181 
182 	if (rate == adg->rbgb_rate_for_48khz_div_6) {
183 		data = 0x20;
184 		goto found_clock;
185 	}
186 
187 	return -EIO;
188 
189 found_clock:
190 
191 	/* see rsnd_adg_ssi_clk_init() */
192 	rsnd_mod_bset(mod, SSICKR, 0x00FF0000, adg->ckr);
193 	rsnd_mod_write(mod, BRRA,  0x00000002); /* 1/6 */
194 	rsnd_mod_write(mod, BRRB,  0x00000002); /* 1/6 */
195 
196 	/*
197 	 * This "mod" = "ssi" here.
198 	 * we can get "ssi id" from mod
199 	 */
200 	rsnd_adg_set_ssi_clk(mod, data);
201 
202 	dev_dbg(dev, "ADG: ssi%d selects clk%d = %d",
203 		rsnd_mod_id(mod), i, rate);
204 
205 	return 0;
206 }
207 
208 static void rsnd_adg_ssi_clk_init(struct rsnd_priv *priv, struct rsnd_adg *adg)
209 {
210 	struct clk *clk;
211 	unsigned long rate;
212 	u32 ckr;
213 	int i;
214 	int brg_table[] = {
215 		[CLKA] = 0x0,
216 		[CLKB] = 0x1,
217 		[CLKC] = 0x4,
218 		[CLKI] = 0x2,
219 	};
220 
221 	/*
222 	 * This driver is assuming that AUDIO_CLKA/AUDIO_CLKB/AUDIO_CLKC
223 	 * have 44.1kHz or 48kHz base clocks for now.
224 	 *
225 	 * SSI itself can divide parent clock by 1/1 - 1/16
226 	 * So,  BRGA outputs 44.1kHz base parent clock 1/32,
227 	 * and, BRGB outputs 48.0kHz base parent clock 1/32 here.
228 	 * see
229 	 *	rsnd_adg_ssi_clk_try_start()
230 	 */
231 	ckr = 0;
232 	adg->rbga_rate_for_441khz_div_6 = 0;
233 	adg->rbgb_rate_for_48khz_div_6  = 0;
234 	for_each_rsnd_clk(clk, adg, i) {
235 		rate = clk_get_rate(clk);
236 
237 		if (0 == rate) /* not used */
238 			continue;
239 
240 		/* RBGA */
241 		if (!adg->rbga_rate_for_441khz_div_6 && (0 == rate % 44100)) {
242 			adg->rbga_rate_for_441khz_div_6 = rate / 6;
243 			ckr |= brg_table[i] << 20;
244 		}
245 
246 		/* RBGB */
247 		if (!adg->rbgb_rate_for_48khz_div_6 && (0 == rate % 48000)) {
248 			adg->rbgb_rate_for_48khz_div_6 = rate / 6;
249 			ckr |= brg_table[i] << 16;
250 		}
251 	}
252 
253 	adg->ckr = ckr;
254 }
255 
256 int rsnd_adg_probe(struct platform_device *pdev,
257 		   struct rcar_snd_info *info,
258 		   struct rsnd_priv *priv)
259 {
260 	struct rsnd_adg *adg;
261 	struct device *dev = rsnd_priv_to_dev(priv);
262 	struct clk *clk;
263 	int i;
264 
265 	adg = devm_kzalloc(dev, sizeof(*adg), GFP_KERNEL);
266 	if (!adg) {
267 		dev_err(dev, "ADG allocate failed\n");
268 		return -ENOMEM;
269 	}
270 
271 	adg->clk[CLKA] = clk_get(NULL, "audio_clk_a");
272 	adg->clk[CLKB] = clk_get(NULL, "audio_clk_b");
273 	adg->clk[CLKC] = clk_get(NULL, "audio_clk_c");
274 	adg->clk[CLKI] = clk_get(NULL, "audio_clk_internal");
275 	for_each_rsnd_clk(clk, adg, i) {
276 		if (IS_ERR(clk)) {
277 			dev_err(dev, "Audio clock failed\n");
278 			return -EIO;
279 		}
280 	}
281 
282 	rsnd_adg_ssi_clk_init(priv, adg);
283 
284 	priv->adg = adg;
285 
286 	dev_dbg(dev, "adg probed\n");
287 
288 	return 0;
289 }
290 
291 void rsnd_adg_remove(struct platform_device *pdev,
292 		     struct rsnd_priv *priv)
293 {
294 	struct rsnd_adg *adg = priv->adg;
295 	struct clk *clk;
296 	int i;
297 
298 	for_each_rsnd_clk(clk, adg, i)
299 		clk_put(clk);
300 }
301