1 // SPDX-License-Identifier: GPL-2.0-or-later
2 // linux/sound/bcm/bcm63xx-i2s-whistler.c
3 // BCM63xx whistler i2s driver
4 // Copyright (c) 2020 Broadcom Corporation
5 // Author: Kevin-Ke Li <kevin-ke.li@broadcom.com>
6 
7 #include <linux/clk.h>
8 #include <linux/dma-mapping.h>
9 #include <linux/io.h>
10 #include <linux/module.h>
11 #include <linux/regmap.h>
12 #include <sound/pcm_params.h>
13 #include <sound/soc.h>
14 #include "bcm63xx-i2s.h"
15 
16 #define DRV_NAME "brcm-i2s"
17 
18 static bool brcm_i2s_wr_reg(struct device *dev, unsigned int reg)
19 {
20 	switch (reg) {
21 	case I2S_TX_CFG ... I2S_TX_DESC_IFF_LEN:
22 	case I2S_TX_CFG_2 ... I2S_RX_DESC_IFF_LEN:
23 	case I2S_RX_CFG_2 ... I2S_REG_MAX:
24 		return true;
25 	default:
26 		return false;
27 	}
28 }
29 
30 static bool brcm_i2s_rd_reg(struct device *dev, unsigned int reg)
31 {
32 	switch (reg) {
33 	case I2S_TX_CFG ... I2S_REG_MAX:
34 		return true;
35 	default:
36 		return false;
37 	}
38 }
39 
40 static bool brcm_i2s_volatile_reg(struct device *dev, unsigned int reg)
41 {
42 	switch (reg) {
43 	case I2S_TX_CFG:
44 	case I2S_TX_IRQ_CTL:
45 	case I2S_TX_DESC_IFF_ADDR:
46 	case I2S_TX_DESC_IFF_LEN:
47 	case I2S_TX_DESC_OFF_ADDR:
48 	case I2S_TX_DESC_OFF_LEN:
49 	case I2S_TX_CFG_2:
50 	case I2S_RX_CFG:
51 	case I2S_RX_IRQ_CTL:
52 	case I2S_RX_DESC_OFF_ADDR:
53 	case I2S_RX_DESC_OFF_LEN:
54 	case I2S_RX_DESC_IFF_LEN:
55 	case I2S_RX_DESC_IFF_ADDR:
56 	case I2S_RX_CFG_2:
57 		return true;
58 	default:
59 		return false;
60 	}
61 }
62 
63 static const struct regmap_config brcm_i2s_regmap_config = {
64 	.reg_bits = 32,
65 	.reg_stride = 4,
66 	.val_bits = 32,
67 	.max_register = I2S_REG_MAX,
68 	.writeable_reg = brcm_i2s_wr_reg,
69 	.readable_reg = brcm_i2s_rd_reg,
70 	.volatile_reg = brcm_i2s_volatile_reg,
71 	.cache_type = REGCACHE_FLAT,
72 };
73 
74 static int bcm63xx_i2s_hw_params(struct snd_pcm_substream *substream,
75 				 struct snd_pcm_hw_params *params,
76 				 struct snd_soc_dai *dai)
77 {
78 	int ret = 0;
79 	struct bcm_i2s_priv *i2s_priv = snd_soc_dai_get_drvdata(dai);
80 
81 	ret = clk_set_rate(i2s_priv->i2s_clk, params_rate(params));
82 	if (ret < 0)
83 		dev_err(i2s_priv->dev,
84 			"Can't set sample rate, err: %d\n", ret);
85 
86 	return ret;
87 }
88 
89 static int bcm63xx_i2s_startup(struct snd_pcm_substream *substream,
90 			       struct snd_soc_dai *dai)
91 {
92 	unsigned int slavemode;
93 	struct bcm_i2s_priv *i2s_priv = snd_soc_dai_get_drvdata(dai);
94 	struct regmap *regmap_i2s = i2s_priv->regmap_i2s;
95 
96 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
97 		regmap_update_bits(regmap_i2s, I2S_TX_CFG,
98 				   I2S_TX_OUT_R | I2S_TX_DATA_ALIGNMENT |
99 				   I2S_TX_DATA_ENABLE | I2S_TX_CLOCK_ENABLE,
100 				   I2S_TX_OUT_R | I2S_TX_DATA_ALIGNMENT |
101 				   I2S_TX_DATA_ENABLE | I2S_TX_CLOCK_ENABLE);
102 		regmap_write(regmap_i2s, I2S_TX_IRQ_CTL, 0);
103 		regmap_write(regmap_i2s, I2S_TX_IRQ_IFF_THLD, 0);
104 		regmap_write(regmap_i2s, I2S_TX_IRQ_OFF_THLD, 1);
105 
106 		/* TX and RX block each have an independent bit to indicate
107 		 * if it is generating the clock for the I2S bus. The bus
108 		 * clocks need to be generated from either the TX or RX block,
109 		 * but not both
110 		 */
111 		regmap_read(regmap_i2s, I2S_RX_CFG_2, &slavemode);
112 		if (slavemode & I2S_RX_SLAVE_MODE_MASK)
113 			regmap_update_bits(regmap_i2s, I2S_TX_CFG_2,
114 					   I2S_TX_SLAVE_MODE_MASK,
115 					   I2S_TX_MASTER_MODE);
116 		else
117 			regmap_update_bits(regmap_i2s, I2S_TX_CFG_2,
118 					   I2S_TX_SLAVE_MODE_MASK,
119 					   I2S_TX_SLAVE_MODE);
120 	} else {
121 		regmap_update_bits(regmap_i2s, I2S_RX_CFG,
122 				   I2S_RX_IN_R | I2S_RX_DATA_ALIGNMENT |
123 				   I2S_RX_CLOCK_ENABLE,
124 				   I2S_RX_IN_R | I2S_RX_DATA_ALIGNMENT |
125 				   I2S_RX_CLOCK_ENABLE);
126 		regmap_write(regmap_i2s, I2S_RX_IRQ_CTL, 0);
127 		regmap_write(regmap_i2s, I2S_RX_IRQ_IFF_THLD, 0);
128 		regmap_write(regmap_i2s, I2S_RX_IRQ_OFF_THLD, 1);
129 
130 		regmap_read(regmap_i2s, I2S_TX_CFG_2, &slavemode);
131 		if (slavemode & I2S_TX_SLAVE_MODE_MASK)
132 			regmap_update_bits(regmap_i2s, I2S_RX_CFG_2,
133 					   I2S_RX_SLAVE_MODE_MASK, 0);
134 		else
135 			regmap_update_bits(regmap_i2s, I2S_RX_CFG_2,
136 					   I2S_RX_SLAVE_MODE_MASK,
137 					   I2S_RX_SLAVE_MODE);
138 	}
139 	return 0;
140 }
141 
142 static void bcm63xx_i2s_shutdown(struct snd_pcm_substream *substream,
143 				struct snd_soc_dai *dai)
144 {
145 	unsigned int enabled, slavemode;
146 	struct bcm_i2s_priv *i2s_priv = snd_soc_dai_get_drvdata(dai);
147 	struct regmap *regmap_i2s = i2s_priv->regmap_i2s;
148 
149 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
150 		regmap_update_bits(regmap_i2s, I2S_TX_CFG,
151 				   I2S_TX_OUT_R | I2S_TX_DATA_ALIGNMENT |
152 				   I2S_TX_DATA_ENABLE | I2S_TX_CLOCK_ENABLE, 0);
153 		regmap_write(regmap_i2s, I2S_TX_IRQ_CTL, 1);
154 		regmap_write(regmap_i2s, I2S_TX_IRQ_IFF_THLD, 4);
155 		regmap_write(regmap_i2s, I2S_TX_IRQ_OFF_THLD, 4);
156 
157 		regmap_read(regmap_i2s, I2S_TX_CFG_2, &slavemode);
158 		slavemode = slavemode & I2S_TX_SLAVE_MODE_MASK;
159 		if (!slavemode) {
160 			regmap_read(regmap_i2s, I2S_RX_CFG, &enabled);
161 			enabled = enabled & I2S_RX_ENABLE_MASK;
162 			if (enabled)
163 				regmap_update_bits(regmap_i2s, I2S_RX_CFG_2,
164 						   I2S_RX_SLAVE_MODE_MASK,
165 						   I2S_RX_MASTER_MODE);
166 		}
167 		regmap_update_bits(regmap_i2s, I2S_TX_CFG_2,
168 				   I2S_TX_SLAVE_MODE_MASK,
169 				   I2S_TX_SLAVE_MODE);
170 	} else {
171 		regmap_update_bits(regmap_i2s, I2S_RX_CFG,
172 				   I2S_RX_IN_R | I2S_RX_DATA_ALIGNMENT |
173 				   I2S_RX_CLOCK_ENABLE, 0);
174 		regmap_write(regmap_i2s, I2S_RX_IRQ_CTL, 1);
175 		regmap_write(regmap_i2s, I2S_RX_IRQ_IFF_THLD, 4);
176 		regmap_write(regmap_i2s, I2S_RX_IRQ_OFF_THLD, 4);
177 
178 		regmap_read(regmap_i2s, I2S_RX_CFG_2, &slavemode);
179 		slavemode = slavemode & I2S_RX_SLAVE_MODE_MASK;
180 		if (!slavemode) {
181 			regmap_read(regmap_i2s, I2S_TX_CFG, &enabled);
182 			enabled = enabled & I2S_TX_ENABLE_MASK;
183 			if (enabled)
184 				regmap_update_bits(regmap_i2s, I2S_TX_CFG_2,
185 						   I2S_TX_SLAVE_MODE_MASK,
186 						   I2S_TX_MASTER_MODE);
187 		}
188 
189 		regmap_update_bits(regmap_i2s, I2S_RX_CFG_2,
190 				   I2S_RX_SLAVE_MODE_MASK, I2S_RX_SLAVE_MODE);
191 	}
192 }
193 
194 static const struct snd_soc_dai_ops bcm63xx_i2s_dai_ops = {
195 	.startup = bcm63xx_i2s_startup,
196 	.shutdown = bcm63xx_i2s_shutdown,
197 	.hw_params = bcm63xx_i2s_hw_params,
198 };
199 
200 static struct snd_soc_dai_driver bcm63xx_i2s_dai = {
201 	.name = DRV_NAME,
202 	.playback = {
203 		.channels_min = 2,
204 		.channels_max = 2,
205 		.rates = SNDRV_PCM_RATE_8000_192000,
206 		.formats = SNDRV_PCM_FMTBIT_S32_LE,
207 	},
208 	.capture = {
209 		.channels_min = 2,
210 		.channels_max = 2,
211 		.rates = SNDRV_PCM_RATE_8000_192000,
212 		.formats = SNDRV_PCM_FMTBIT_S32_LE,
213 	},
214 	.ops = &bcm63xx_i2s_dai_ops,
215 	.symmetric_rates = 1,
216 	.symmetric_channels = 1,
217 };
218 
219 static const struct snd_soc_component_driver bcm63xx_i2s_component = {
220 	.name = "bcm63xx",
221 };
222 
223 static int bcm63xx_i2s_dev_probe(struct platform_device *pdev)
224 {
225 	int ret = 0;
226 	void __iomem *regs;
227 	struct resource *r_mem, *region;
228 	struct bcm_i2s_priv *i2s_priv;
229 	struct regmap *regmap_i2s;
230 	struct clk *i2s_clk;
231 
232 	i2s_priv = devm_kzalloc(&pdev->dev, sizeof(*i2s_priv), GFP_KERNEL);
233 	if (!i2s_priv)
234 		return -ENOMEM;
235 
236 	i2s_clk = devm_clk_get(&pdev->dev, "i2sclk");
237 	if (IS_ERR(i2s_clk)) {
238 		dev_err(&pdev->dev, "%s: cannot get a brcm clock: %ld\n",
239 					__func__, PTR_ERR(i2s_clk));
240 		return PTR_ERR(i2s_clk);
241 	}
242 
243 	r_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
244 	if (!r_mem) {
245 		dev_err(&pdev->dev, "Unable to get register resource.\n");
246 		return -ENODEV;
247 	}
248 
249 	region = devm_request_mem_region(&pdev->dev, r_mem->start,
250 					resource_size(r_mem), DRV_NAME);
251 	if (!region) {
252 		dev_err(&pdev->dev, "Memory region already claimed\n");
253 		return -EBUSY;
254 	}
255 
256 	regs = devm_ioremap_resource(&pdev->dev, r_mem);
257 	if (IS_ERR(regs)) {
258 		ret = PTR_ERR(regs);
259 		return ret;
260 	}
261 
262 	regmap_i2s = devm_regmap_init_mmio(&pdev->dev,
263 					regs, &brcm_i2s_regmap_config);
264 	if (IS_ERR(regmap_i2s))
265 		return PTR_ERR(regmap_i2s);
266 
267 	regmap_update_bits(regmap_i2s, I2S_MISC_CFG,
268 			   I2S_PAD_LVL_LOOP_DIS_MASK,
269 			   I2S_PAD_LVL_LOOP_DIS_ENABLE);
270 
271 	ret = devm_snd_soc_register_component(&pdev->dev,
272 					      &bcm63xx_i2s_component,
273 					      &bcm63xx_i2s_dai, 1);
274 	if (ret) {
275 		dev_err(&pdev->dev, "failed to register the dai\n");
276 		return ret;
277 	}
278 
279 	i2s_priv->dev = &pdev->dev;
280 	i2s_priv->i2s_clk = i2s_clk;
281 	i2s_priv->regmap_i2s = regmap_i2s;
282 	dev_set_drvdata(&pdev->dev, i2s_priv);
283 
284 	ret = bcm63xx_soc_platform_probe(pdev, i2s_priv);
285 	if (ret)
286 		dev_err(&pdev->dev, "failed to register the pcm\n");
287 
288 	return ret;
289 }
290 
291 static int bcm63xx_i2s_dev_remove(struct platform_device *pdev)
292 {
293 	bcm63xx_soc_platform_remove(pdev);
294 	return 0;
295 }
296 
297 #ifdef CONFIG_OF
298 static const struct of_device_id snd_soc_bcm_audio_match[] = {
299 	{.compatible = "brcm,bcm63xx-i2s"},
300 	{ }
301 };
302 #endif
303 
304 static struct platform_driver bcm63xx_i2s_driver = {
305 	.driver = {
306 		.name = DRV_NAME,
307 		.of_match_table = of_match_ptr(snd_soc_bcm_audio_match),
308 	},
309 	.probe = bcm63xx_i2s_dev_probe,
310 	.remove = bcm63xx_i2s_dev_remove,
311 };
312 
313 module_platform_driver(bcm63xx_i2s_driver);
314 
315 MODULE_AUTHOR("Kevin,Li <kevin-ke.li@broadcom.com>");
316 MODULE_DESCRIPTION("Broadcom DSL XPON ASOC I2S Interface");
317 MODULE_LICENSE("GPL v2");
318