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af48f1d0 OC |
1 | /* |
2 | * rt5677-spi.c -- RT5677 ALSA SoC audio codec driver | |
3 | * | |
4 | * Copyright 2013 Realtek Semiconductor Corp. | |
5 | * Author: Oder Chiou <oder_chiou@realtek.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/input.h> | |
14 | #include <linux/spi/spi.h> | |
15 | #include <linux/device.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/delay.h> | |
18 | #include <linux/interrupt.h> | |
19 | #include <linux/irq.h> | |
20 | #include <linux/slab.h> | |
21 | #include <linux/gpio.h> | |
22 | #include <linux/sched.h> | |
23 | #include <linux/kthread.h> | |
24 | #include <linux/uaccess.h> | |
25 | #include <linux/miscdevice.h> | |
26 | #include <linux/regulator/consumer.h> | |
27 | #include <linux/pm_qos.h> | |
28 | #include <linux/sysfs.h> | |
29 | #include <linux/clk.h> | |
30 | #include <linux/firmware.h> | |
31 | ||
32 | #include "rt5677-spi.h" | |
33 | ||
7d4d443e BZ |
34 | #define RT5677_SPI_BURST_LEN 240 |
35 | #define RT5677_SPI_HEADER 5 | |
36 | #define RT5677_SPI_FREQ 6000000 | |
37 | ||
38 | /* The AddressPhase and DataPhase of SPI commands are MSB first on the wire. | |
39 | * DataPhase word size of 16-bit commands is 2 bytes. | |
40 | * DataPhase word size of 32-bit commands is 4 bytes. | |
41 | * DataPhase word size of burst commands is 8 bytes. | |
42 | * The DSP CPU is little-endian. | |
43 | */ | |
44 | #define RT5677_SPI_WRITE_BURST 0x5 | |
45 | #define RT5677_SPI_READ_BURST 0x4 | |
46 | #define RT5677_SPI_WRITE_32 0x3 | |
47 | #define RT5677_SPI_READ_32 0x2 | |
48 | #define RT5677_SPI_WRITE_16 0x1 | |
49 | #define RT5677_SPI_READ_16 0x0 | |
50 | ||
af48f1d0 | 51 | static struct spi_device *g_spi; |
7d4d443e | 52 | static DEFINE_MUTEX(spi_mutex); |
af48f1d0 | 53 | |
7d4d443e BZ |
54 | /* Select a suitable transfer command for the next transfer to ensure |
55 | * the transfer address is always naturally aligned while minimizing | |
56 | * the total number of transfers required. | |
57 | * | |
58 | * 3 transfer commands are available: | |
59 | * RT5677_SPI_READ/WRITE_16: Transfer 2 bytes | |
60 | * RT5677_SPI_READ/WRITE_32: Transfer 4 bytes | |
61 | * RT5677_SPI_READ/WRITE_BURST: Transfer any multiples of 8 bytes | |
62 | * | |
63 | * For example, reading 260 bytes at 0x60030002 uses the following commands: | |
64 | * 0x60030002 RT5677_SPI_READ_16 2 bytes | |
65 | * 0x60030004 RT5677_SPI_READ_32 4 bytes | |
66 | * 0x60030008 RT5677_SPI_READ_BURST 240 bytes | |
67 | * 0x600300F8 RT5677_SPI_READ_BURST 8 bytes | |
68 | * 0x60030100 RT5677_SPI_READ_32 4 bytes | |
69 | * 0x60030104 RT5677_SPI_READ_16 2 bytes | |
af48f1d0 | 70 | * |
7d4d443e BZ |
71 | * Input: |
72 | * @read: true for read commands; false for write commands | |
73 | * @align: alignment of the next transfer address | |
74 | * @remain: number of bytes remaining to transfer | |
af48f1d0 | 75 | * |
7d4d443e BZ |
76 | * Output: |
77 | * @len: number of bytes to transfer with the selected command | |
78 | * Returns the selected command | |
af48f1d0 | 79 | */ |
7d4d443e | 80 | static u8 rt5677_spi_select_cmd(bool read, u32 align, u32 remain, u32 *len) |
af48f1d0 | 81 | { |
7d4d443e BZ |
82 | u8 cmd; |
83 | ||
84 | if (align == 2 || align == 6 || remain == 2) { | |
85 | cmd = RT5677_SPI_READ_16; | |
86 | *len = 2; | |
87 | } else if (align == 4 || remain <= 6) { | |
88 | cmd = RT5677_SPI_READ_32; | |
89 | *len = 4; | |
90 | } else { | |
91 | cmd = RT5677_SPI_READ_BURST; | |
92 | *len = min_t(u32, remain & ~7, RT5677_SPI_BURST_LEN); | |
93 | } | |
94 | return read ? cmd : cmd + 1; | |
af48f1d0 OC |
95 | } |
96 | ||
7d4d443e BZ |
97 | /* Copy dstlen bytes from src to dst, while reversing byte order for each word. |
98 | * If srclen < dstlen, zeros are padded. | |
af48f1d0 | 99 | */ |
7d4d443e | 100 | static void rt5677_spi_reverse(u8 *dst, u32 dstlen, const u8 *src, u32 srclen) |
af48f1d0 | 101 | { |
7d4d443e BZ |
102 | u32 w, i, si; |
103 | u32 word_size = min_t(u32, dstlen, 8); | |
104 | ||
105 | for (w = 0; w < dstlen; w += word_size) { | |
106 | for (i = 0; i < word_size; i++) { | |
107 | si = w + word_size - i - 1; | |
108 | dst[w + i] = si < srclen ? src[si] : 0; | |
af48f1d0 | 109 | } |
7d4d443e BZ |
110 | } |
111 | } | |
af48f1d0 | 112 | |
7d4d443e BZ |
113 | /* Read DSP address space using SPI. addr and len have to be 2-byte aligned. */ |
114 | int rt5677_spi_read(u32 addr, void *rxbuf, size_t len) | |
115 | { | |
116 | u32 offset; | |
117 | int status = 0; | |
118 | struct spi_transfer t[2]; | |
119 | struct spi_message m; | |
120 | /* +4 bytes is for the DummyPhase following the AddressPhase */ | |
121 | u8 header[RT5677_SPI_HEADER + 4]; | |
122 | u8 body[RT5677_SPI_BURST_LEN]; | |
123 | u8 spi_cmd; | |
124 | u8 *cb = rxbuf; | |
125 | ||
126 | if (!g_spi) | |
127 | return -ENODEV; | |
128 | ||
129 | if ((addr & 1) || (len & 1)) { | |
130 | dev_err(&g_spi->dev, "Bad read align 0x%x(%zu)\n", addr, len); | |
131 | return -EACCES; | |
132 | } | |
af48f1d0 | 133 | |
7d4d443e BZ |
134 | memset(t, 0, sizeof(t)); |
135 | t[0].tx_buf = header; | |
136 | t[0].len = sizeof(header); | |
137 | t[0].speed_hz = RT5677_SPI_FREQ; | |
138 | t[1].rx_buf = body; | |
139 | t[1].speed_hz = RT5677_SPI_FREQ; | |
140 | spi_message_init_with_transfers(&m, t, ARRAY_SIZE(t)); | |
141 | ||
142 | for (offset = 0; offset < len; offset += t[1].len) { | |
143 | spi_cmd = rt5677_spi_select_cmd(true, (addr + offset) & 7, | |
144 | len - offset, &t[1].len); | |
145 | ||
146 | /* Construct SPI message header */ | |
147 | header[0] = spi_cmd; | |
148 | header[1] = ((addr + offset) & 0xff000000) >> 24; | |
149 | header[2] = ((addr + offset) & 0x00ff0000) >> 16; | |
150 | header[3] = ((addr + offset) & 0x0000ff00) >> 8; | |
151 | header[4] = ((addr + offset) & 0x000000ff) >> 0; | |
152 | ||
153 | mutex_lock(&spi_mutex); | |
154 | status |= spi_sync(g_spi, &m); | |
155 | mutex_unlock(&spi_mutex); | |
156 | ||
157 | /* Copy data back to caller buffer */ | |
158 | rt5677_spi_reverse(cb + offset, t[1].len, body, t[1].len); | |
159 | } | |
160 | return status; | |
161 | } | |
162 | EXPORT_SYMBOL_GPL(rt5677_spi_read); | |
af48f1d0 | 163 | |
7d4d443e BZ |
164 | /* Write DSP address space using SPI. addr has to be 2-byte aligned. |
165 | * If len is not 2-byte aligned, an extra byte of zero is written at the end | |
166 | * as padding. | |
167 | */ | |
168 | int rt5677_spi_write(u32 addr, const void *txbuf, size_t len) | |
169 | { | |
170 | u32 offset, len_with_pad = len; | |
171 | int status = 0; | |
172 | struct spi_transfer t; | |
173 | struct spi_message m; | |
174 | /* +1 byte is for the DummyPhase following the DataPhase */ | |
175 | u8 buf[RT5677_SPI_HEADER + RT5677_SPI_BURST_LEN + 1]; | |
176 | u8 *body = buf + RT5677_SPI_HEADER; | |
177 | u8 spi_cmd; | |
178 | const u8 *cb = txbuf; | |
179 | ||
180 | if (!g_spi) | |
181 | return -ENODEV; | |
182 | ||
183 | if (addr & 1) { | |
184 | dev_err(&g_spi->dev, "Bad write align 0x%x(%zu)\n", addr, len); | |
185 | return -EACCES; | |
af48f1d0 OC |
186 | } |
187 | ||
7d4d443e BZ |
188 | if (len & 1) |
189 | len_with_pad = len + 1; | |
190 | ||
191 | memset(&t, 0, sizeof(t)); | |
192 | t.tx_buf = buf; | |
193 | t.speed_hz = RT5677_SPI_FREQ; | |
194 | spi_message_init_with_transfers(&m, &t, 1); | |
195 | ||
196 | for (offset = 0; offset < len_with_pad;) { | |
197 | spi_cmd = rt5677_spi_select_cmd(false, (addr + offset) & 7, | |
198 | len_with_pad - offset, &t.len); | |
199 | ||
200 | /* Construct SPI message header */ | |
201 | buf[0] = spi_cmd; | |
202 | buf[1] = ((addr + offset) & 0xff000000) >> 24; | |
203 | buf[2] = ((addr + offset) & 0x00ff0000) >> 16; | |
204 | buf[3] = ((addr + offset) & 0x0000ff00) >> 8; | |
205 | buf[4] = ((addr + offset) & 0x000000ff) >> 0; | |
206 | ||
207 | /* Fetch data from caller buffer */ | |
208 | rt5677_spi_reverse(body, t.len, cb + offset, len - offset); | |
209 | offset += t.len; | |
210 | t.len += RT5677_SPI_HEADER + 1; | |
211 | ||
212 | mutex_lock(&spi_mutex); | |
213 | status |= spi_sync(g_spi, &m); | |
214 | mutex_unlock(&spi_mutex); | |
215 | } | |
216 | return status; | |
217 | } | |
218 | EXPORT_SYMBOL_GPL(rt5677_spi_write); | |
af48f1d0 | 219 | |
7d4d443e BZ |
220 | int rt5677_spi_write_firmware(u32 addr, const struct firmware *fw) |
221 | { | |
222 | return rt5677_spi_write(addr, fw->data, fw->size); | |
af48f1d0 | 223 | } |
7d4d443e | 224 | EXPORT_SYMBOL_GPL(rt5677_spi_write_firmware); |
af48f1d0 OC |
225 | |
226 | static int rt5677_spi_probe(struct spi_device *spi) | |
227 | { | |
228 | g_spi = spi; | |
229 | return 0; | |
230 | } | |
231 | ||
232 | static struct spi_driver rt5677_spi_driver = { | |
233 | .driver = { | |
234 | .name = "rt5677", | |
235 | .owner = THIS_MODULE, | |
236 | }, | |
237 | .probe = rt5677_spi_probe, | |
238 | }; | |
239 | module_spi_driver(rt5677_spi_driver); | |
240 | ||
241 | MODULE_DESCRIPTION("ASoC RT5677 SPI driver"); | |
242 | MODULE_AUTHOR("Oder Chiou <oder_chiou@realtek.com>"); | |
243 | MODULE_LICENSE("GPL v2"); |