xref: /openbmc/linux/sound/soc/fsl/mpc5200_psc_i2s.c (revision 7dd65feb)
1 /*
2  * Freescale MPC5200 PSC in I2S mode
3  * ALSA SoC Digital Audio Interface (DAI) driver
4  *
5  * Copyright (C) 2008 Secret Lab Technologies Ltd.
6  * Copyright (C) 2009 Jon Smirl, Digispeaker
7  */
8 
9 #include <linux/module.h>
10 #include <linux/of_device.h>
11 #include <linux/of_platform.h>
12 
13 #include <sound/pcm.h>
14 #include <sound/pcm_params.h>
15 #include <sound/soc.h>
16 
17 #include <asm/mpc52xx_psc.h>
18 
19 #include "mpc5200_psc_i2s.h"
20 #include "mpc5200_dma.h"
21 
22 /**
23  * PSC_I2S_RATES: sample rates supported by the I2S
24  *
25  * This driver currently only supports the PSC running in I2S slave mode,
26  * which means the codec determines the sample rate.  Therefore, we tell
27  * ALSA that we support all rates and let the codec driver decide what rates
28  * are really supported.
29  */
30 #define PSC_I2S_RATES (SNDRV_PCM_RATE_5512 | SNDRV_PCM_RATE_8000_192000 | \
31 			SNDRV_PCM_RATE_CONTINUOUS)
32 
33 /**
34  * PSC_I2S_FORMATS: audio formats supported by the PSC I2S mode
35  */
36 #define PSC_I2S_FORMATS (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE | \
37 			 SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S32_BE)
38 
39 static int psc_i2s_hw_params(struct snd_pcm_substream *substream,
40 				 struct snd_pcm_hw_params *params,
41 				 struct snd_soc_dai *dai)
42 {
43 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
44 	struct psc_dma *psc_dma = rtd->dai->cpu_dai->private_data;
45 	u32 mode;
46 
47 	dev_dbg(psc_dma->dev, "%s(substream=%p) p_size=%i p_bytes=%i"
48 		" periods=%i buffer_size=%i  buffer_bytes=%i\n",
49 		__func__, substream, params_period_size(params),
50 		params_period_bytes(params), params_periods(params),
51 		params_buffer_size(params), params_buffer_bytes(params));
52 
53 	switch (params_format(params)) {
54 	case SNDRV_PCM_FORMAT_S8:
55 		mode = MPC52xx_PSC_SICR_SIM_CODEC_8;
56 		break;
57 	case SNDRV_PCM_FORMAT_S16_BE:
58 		mode = MPC52xx_PSC_SICR_SIM_CODEC_16;
59 		break;
60 	case SNDRV_PCM_FORMAT_S24_BE:
61 		mode = MPC52xx_PSC_SICR_SIM_CODEC_24;
62 		break;
63 	case SNDRV_PCM_FORMAT_S32_BE:
64 		mode = MPC52xx_PSC_SICR_SIM_CODEC_32;
65 		break;
66 	default:
67 		dev_dbg(psc_dma->dev, "invalid format\n");
68 		return -EINVAL;
69 	}
70 	out_be32(&psc_dma->psc_regs->sicr, psc_dma->sicr | mode);
71 
72 	return 0;
73 }
74 
75 /**
76  * psc_i2s_set_sysclk: set the clock frequency and direction
77  *
78  * This function is called by the machine driver to tell us what the clock
79  * frequency and direction are.
80  *
81  * Currently, we only support operating as a clock slave (SND_SOC_CLOCK_IN),
82  * and we don't care about the frequency.  Return an error if the direction
83  * is not SND_SOC_CLOCK_IN.
84  *
85  * @clk_id: reserved, should be zero
86  * @freq: the frequency of the given clock ID, currently ignored
87  * @dir: SND_SOC_CLOCK_IN (clock slave) or SND_SOC_CLOCK_OUT (clock master)
88  */
89 static int psc_i2s_set_sysclk(struct snd_soc_dai *cpu_dai,
90 			      int clk_id, unsigned int freq, int dir)
91 {
92 	struct psc_dma *psc_dma = cpu_dai->private_data;
93 	dev_dbg(psc_dma->dev, "psc_i2s_set_sysclk(cpu_dai=%p, dir=%i)\n",
94 				cpu_dai, dir);
95 	return (dir == SND_SOC_CLOCK_IN) ? 0 : -EINVAL;
96 }
97 
98 /**
99  * psc_i2s_set_fmt: set the serial format.
100  *
101  * This function is called by the machine driver to tell us what serial
102  * format to use.
103  *
104  * This driver only supports I2S mode.  Return an error if the format is
105  * not SND_SOC_DAIFMT_I2S.
106  *
107  * @format: one of SND_SOC_DAIFMT_xxx
108  */
109 static int psc_i2s_set_fmt(struct snd_soc_dai *cpu_dai, unsigned int format)
110 {
111 	struct psc_dma *psc_dma = cpu_dai->private_data;
112 	dev_dbg(psc_dma->dev, "psc_i2s_set_fmt(cpu_dai=%p, format=%i)\n",
113 				cpu_dai, format);
114 	return (format == SND_SOC_DAIFMT_I2S) ? 0 : -EINVAL;
115 }
116 
117 /* ---------------------------------------------------------------------
118  * ALSA SoC Bindings
119  *
120  * - Digital Audio Interface (DAI) template
121  * - create/destroy dai hooks
122  */
123 
124 /**
125  * psc_i2s_dai_template: template CPU Digital Audio Interface
126  */
127 static struct snd_soc_dai_ops psc_i2s_dai_ops = {
128 	.hw_params	= psc_i2s_hw_params,
129 	.set_sysclk	= psc_i2s_set_sysclk,
130 	.set_fmt	= psc_i2s_set_fmt,
131 };
132 
133 struct snd_soc_dai psc_i2s_dai[] = {{
134 	.name   = "I2S",
135 	.playback = {
136 		.channels_min = 2,
137 		.channels_max = 2,
138 		.rates = PSC_I2S_RATES,
139 		.formats = PSC_I2S_FORMATS,
140 	},
141 	.capture = {
142 		.channels_min = 2,
143 		.channels_max = 2,
144 		.rates = PSC_I2S_RATES,
145 		.formats = PSC_I2S_FORMATS,
146 	},
147 	.ops = &psc_i2s_dai_ops,
148 } };
149 EXPORT_SYMBOL_GPL(psc_i2s_dai);
150 
151 /* ---------------------------------------------------------------------
152  * OF platform bus binding code:
153  * - Probe/remove operations
154  * - OF device match table
155  */
156 static int __devinit psc_i2s_of_probe(struct of_device *op,
157 				      const struct of_device_id *match)
158 {
159 	int rc;
160 	struct psc_dma *psc_dma;
161 	struct mpc52xx_psc __iomem *regs;
162 
163 	rc = mpc5200_audio_dma_create(op);
164 	if (rc != 0)
165 		return rc;
166 
167 	rc = snd_soc_register_dais(psc_i2s_dai, ARRAY_SIZE(psc_i2s_dai));
168 	if (rc != 0) {
169 		pr_err("Failed to register DAI\n");
170 		return 0;
171 	}
172 
173 	psc_dma = dev_get_drvdata(&op->dev);
174 	regs = psc_dma->psc_regs;
175 
176 	/* Configure the serial interface mode; defaulting to CODEC8 mode */
177 	psc_dma->sicr = MPC52xx_PSC_SICR_DTS1 | MPC52xx_PSC_SICR_I2S |
178 			MPC52xx_PSC_SICR_CLKPOL;
179 	out_be32(&psc_dma->psc_regs->sicr,
180 		 psc_dma->sicr | MPC52xx_PSC_SICR_SIM_CODEC_8);
181 
182 	/* Check for the codec handle.  If it is not present then we
183 	 * are done */
184 	if (!of_get_property(op->node, "codec-handle", NULL))
185 		return 0;
186 
187 	/* Due to errata in the dma mode; need to line up enabling
188 	 * the transmitter with a transition on the frame sync
189 	 * line */
190 
191 	/* first make sure it is low */
192 	while ((in_8(&regs->ipcr_acr.ipcr) & 0x80) != 0)
193 		;
194 	/* then wait for the transition to high */
195 	while ((in_8(&regs->ipcr_acr.ipcr) & 0x80) == 0)
196 		;
197 	/* Finally, enable the PSC.
198 	 * Receiver must always be enabled; even when we only want
199 	 * transmit.  (see 15.3.2.3 of MPC5200B User's Guide) */
200 
201 	/* Go */
202 	out_8(&psc_dma->psc_regs->command,
203 			MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE);
204 
205 	return 0;
206 
207 }
208 
209 static int __devexit psc_i2s_of_remove(struct of_device *op)
210 {
211 	return mpc5200_audio_dma_destroy(op);
212 }
213 
214 /* Match table for of_platform binding */
215 static struct of_device_id psc_i2s_match[] __devinitdata = {
216 	{ .compatible = "fsl,mpc5200-psc-i2s", },
217 	{ .compatible = "fsl,mpc5200b-psc-i2s", },
218 	{}
219 };
220 MODULE_DEVICE_TABLE(of, psc_i2s_match);
221 
222 static struct of_platform_driver psc_i2s_driver = {
223 	.match_table = psc_i2s_match,
224 	.probe = psc_i2s_of_probe,
225 	.remove = __devexit_p(psc_i2s_of_remove),
226 	.driver = {
227 		.name = "mpc5200-psc-i2s",
228 		.owner = THIS_MODULE,
229 	},
230 };
231 
232 /* ---------------------------------------------------------------------
233  * Module setup and teardown; simply register the of_platform driver
234  * for the PSC in I2S mode.
235  */
236 static int __init psc_i2s_init(void)
237 {
238 	return of_register_platform_driver(&psc_i2s_driver);
239 }
240 module_init(psc_i2s_init);
241 
242 static void __exit psc_i2s_exit(void)
243 {
244 	of_unregister_platform_driver(&psc_i2s_driver);
245 }
246 module_exit(psc_i2s_exit);
247 
248 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
249 MODULE_DESCRIPTION("Freescale MPC5200 PSC in I2S mode ASoC Driver");
250 MODULE_LICENSE("GPL");
251 
252