1 // SPDX-License-Identifier: GPL-2.0+159
2 /*
3  * Take from dc tegra_ahub.c
4  *
5  * Copyright 2018 Google LLC
6  */
7 
8 #define LOG_CATEGORY UCLASS_MISC
9 
10 #include <common.h>
11 #include <dm.h>
12 #include <i2s.h>
13 #include <log.h>
14 #include <misc.h>
15 #include <asm/io.h>
16 #include <asm/arch-tegra/tegra_ahub.h>
17 #include <asm/arch-tegra/tegra_i2s.h>
18 #include "tegra_i2s_priv.h"
19 
20 struct tegra_ahub_priv {
21 	struct apbif_regs *apbif_regs;
22 	struct xbar_regs *xbar_regs;
23 	u32 full_mask;
24 	int capacity_words;  /* FIFO capacity in words */
25 
26 	/*
27 	 * This is unset intially, but is set by tegra_ahub_ioctl() called
28 	 * from the misc_ioctl() in tegra_sound_probe()
29 	 */
30 	struct udevice *i2s;
31 	struct udevice *dma;
32 };
33 
34 static int tegra_ahub_xbar_enable_i2s(struct xbar_regs *regs, int i2s_id)
35 {
36 	/*
37 	 * Enables I2S as the receiver of APBIF by writing APBIF_TX0 (0x01) to
38 	 * the rx0 register
39 	 */
40 	switch (i2s_id) {
41 	case 0:
42 		writel(1, &regs->i2s0_rx0);
43 		break;
44 	case 1:
45 		writel(1, &regs->i2s1_rx0);
46 		break;
47 	case 2:
48 		writel(1, &regs->i2s2_rx0);
49 		break;
50 	case 3:
51 		writel(1, &regs->i2s3_rx0);
52 		break;
53 	case 4:
54 		writel(1, &regs->i2s4_rx0);
55 		break;
56 	default:
57 		log_err("Invalid I2S component id: %d\n", i2s_id);
58 		return -EINVAL;
59 	}
60 	return 0;
61 }
62 
63 static int tegra_ahub_apbif_is_full(struct udevice *dev)
64 {
65 	struct tegra_ahub_priv *priv = dev_get_priv(dev);
66 
67 	return readl(&priv->apbif_regs->apbdma_live_stat) & priv->full_mask;
68 }
69 
70 /**
71  * tegra_ahub_wait_for_space() - Wait for space in the FIFO
72  *
73  * @return 0 if OK, -ETIMEDOUT if no space was available in time
74  */
75 static int tegra_ahub_wait_for_space(struct udevice *dev)
76 {
77 	int i = 100000;
78 	ulong start;
79 
80 	/* Busy-wait initially, since this should take almost no time */
81 	while (i--) {
82 		if (!tegra_ahub_apbif_is_full(dev))
83 			return 0;
84 	}
85 
86 	/* Failed, so do a slower loop for 100ms */
87 	start = get_timer(0);
88 	while (tegra_ahub_apbif_is_full(dev)) {
89 		if (get_timer(start) > 100)
90 			return -ETIMEDOUT;
91 	}
92 
93 	return 0;
94 }
95 
96 static int tegra_ahub_apbif_send(struct udevice *dev, int offset,
97 				 const void *buf, int len)
98 {
99 	struct tegra_ahub_priv *priv = dev_get_priv(dev);
100 	const u32 *data = (const u32 *)buf;
101 	ssize_t written = 0;
102 
103 	if (len % sizeof(*data)) {
104 		log_err("Data size (%zd) must be aligned to %zd.\n", len,
105 			sizeof(*data));
106 		return -EFAULT;
107 	}
108 	while (written < len) {
109 		int ret = tegra_ahub_wait_for_space(dev);
110 
111 		if (ret)
112 			return ret;
113 
114 		writel(*data++, &priv->apbif_regs->channel0_txfifo);
115 		written += sizeof(*data);
116 	}
117 
118 	return written;
119 }
120 
121 static void tegra_ahub_apbif_set_cif(struct udevice *dev, u32 value)
122 {
123 	struct tegra_ahub_priv *priv = dev_get_priv(dev);
124 
125 	writel(value, &priv->apbif_regs->channel0_cif_tx0_ctrl);
126 }
127 
128 static void tegra_ahub_apbif_enable_channel0(struct udevice *dev,
129 					     int fifo_threshold)
130 {
131 	struct tegra_ahub_priv *priv = dev_get_priv(dev);
132 
133 	u32 ctrl = TEGRA_AHUB_CHANNEL_CTRL_TX_PACK_EN |
134 			TEGRA_AHUB_CHANNEL_CTRL_TX_PACK_16 |
135 			TEGRA_AHUB_CHANNEL_CTRL_TX_EN;
136 
137 	fifo_threshold--; /* fifo_threshold starts from 1 */
138 	ctrl |= (fifo_threshold << TEGRA_AHUB_CHANNEL_CTRL_TX_THRESHOLD_SHIFT);
139 	writel(ctrl, &priv->apbif_regs->channel0_ctrl);
140 }
141 
142 static u32 tegra_ahub_get_cif(bool is_receive, uint channels,
143 			      uint bits_per_sample, uint fifo_threshold)
144 {
145 	uint audio_bits = (bits_per_sample >> 2) - 1;
146 	u32 val;
147 
148 	channels--;  /* Channels in CIF starts from 1 */
149 	fifo_threshold--;  /* FIFO threshold starts from 1 */
150 	/* Assume input and output are always using same channel / bits */
151 	val = channels << TEGRA_AUDIOCIF_CTRL_AUDIO_CHANNELS_SHIFT |
152 	      channels << TEGRA_AUDIOCIF_CTRL_CLIENT_CHANNELS_SHIFT |
153 	      audio_bits << TEGRA_AUDIOCIF_CTRL_AUDIO_BITS_SHIFT |
154 	      audio_bits << TEGRA_AUDIOCIF_CTRL_CLIENT_BITS_SHIFT |
155 	      fifo_threshold << TEGRA_AUDIOCIF_CTRL_FIFO_THRESHOLD_SHIFT |
156 	      (is_receive ? TEGRA_AUDIOCIF_DIRECTION_RX <<
157 			    TEGRA_AUDIOCIF_CTRL_DIRECTION_SHIFT : 0);
158 
159 	return val;
160 }
161 
162 static int tegra_ahub_enable(struct udevice *dev)
163 {
164 	struct tegra_ahub_priv *priv = dev_get_priv(dev);
165 	struct i2s_uc_priv *uc_priv = dev_get_uclass_priv(priv->i2s);
166 	u32 cif_ctrl = 0;
167 	int ret;
168 
169 	/* We use APBIF channel0 as a sender */
170 	priv->full_mask = TEGRA_AHUB_APBDMA_LIVE_STATUS_CH0_TX_CIF_FIFO_FULL;
171 	priv->capacity_words = 8;
172 
173 	/*
174 	 * FIFO is inactive until (fifo_threshold) of words are sent. For
175 	 * better performance, we want to set it to half of capacity.
176 	 */
177 	u32 fifo_threshold = priv->capacity_words / 2;
178 
179 	/*
180 	 * Setup audio client interface (ACIF): APBIF (channel0) as sender and
181 	 * I2S as receiver
182 	 */
183 	cif_ctrl = tegra_ahub_get_cif(true, uc_priv->channels,
184 				      uc_priv->bitspersample, fifo_threshold);
185 	tegra_i2s_set_cif_tx_ctrl(priv->i2s, cif_ctrl);
186 
187 	cif_ctrl = tegra_ahub_get_cif(false, uc_priv->channels,
188 				      uc_priv->bitspersample, fifo_threshold);
189 	tegra_ahub_apbif_set_cif(dev, cif_ctrl);
190 	tegra_ahub_apbif_enable_channel0(dev, fifo_threshold);
191 
192 	ret = tegra_ahub_xbar_enable_i2s(priv->xbar_regs, uc_priv->id);
193 	if (ret)
194 		return ret;
195 	log_debug("ahub: channels=%d, bitspersample=%d, cif_ctrl=%x, fifo_threshold=%d, id=%d\n",
196 		  uc_priv->channels, uc_priv->bitspersample, cif_ctrl,
197 		  fifo_threshold, uc_priv->id);
198 
199 	return 0;
200 }
201 
202 static int tegra_ahub_ioctl(struct udevice *dev, unsigned long request,
203 			    void *buf)
204 {
205 	struct tegra_ahub_priv *priv = dev_get_priv(dev);
206 
207 	if (request != AHUB_MISCOP_SET_I2S)
208 		return -ENOSYS;
209 
210 	priv->i2s = *(struct udevice **)buf;
211 	log_debug("i2s set to '%s'\n", priv->i2s->name);
212 
213 	return tegra_ahub_enable(dev);
214 }
215 
216 static int tegra_ahub_probe(struct udevice *dev)
217 {
218 	struct tegra_ahub_priv *priv = dev_get_priv(dev);
219 	ulong addr;
220 
221 	addr = dev_read_addr_index(dev, 0);
222 	if (addr == FDT_ADDR_T_NONE) {
223 		log_debug("Invalid apbif address\n");
224 		return -EINVAL;
225 	}
226 	priv->apbif_regs = (struct apbif_regs *)addr;
227 
228 	addr = dev_read_addr_index(dev, 1);
229 	if (addr == FDT_ADDR_T_NONE) {
230 		log_debug("Invalid xbar address\n");
231 		return -EINVAL;
232 	}
233 	priv->xbar_regs = (struct xbar_regs *)addr;
234 	log_debug("ahub apbif_regs=%p, xbar_regs=%p\n", priv->apbif_regs,
235 		  priv->xbar_regs);
236 
237 	return 0;
238 }
239 
240 static struct misc_ops tegra_ahub_ops = {
241 	.write		= tegra_ahub_apbif_send,
242 	.ioctl		= tegra_ahub_ioctl,
243 };
244 
245 static const struct udevice_id tegra_ahub_ids[] = {
246 	{ .compatible = "nvidia,tegra124-ahub" },
247 	{ }
248 };
249 
250 U_BOOT_DRIVER(tegra_ahub) = {
251 	.name		= "tegra_ahub",
252 	.id		= UCLASS_MISC,
253 	.of_match	= tegra_ahub_ids,
254 	.ops		= &tegra_ahub_ops,
255 	.probe		= tegra_ahub_probe,
256 	.priv_auto	= sizeof(struct tegra_ahub_priv),
257 };
258