1 // SPDX-License-Identifier: GPL-2.0-only
3  * rt5677-spi.c  --  RT5677 ALSA SoC audio codec driver
11 #include <linux/spi/spi.h>
27 #include "rt5677-spi.h"
35 /* The AddressPhase and DataPhase of SPI commands are MSB first on the wire.
36  * DataPhase word size of 16-bit commands is 2 bytes.
37  * DataPhase word size of 32-bit commands is 4 bytes.
39  * The DSP CPU is little-endian.
55  * 3 transfer commands are available:
88 		*len = (((remain - 1) >> 3) + 1) << 3;  in rt5677_spi_select_cmd()
104 			si = w + word_size - i - 1;  in rt5677_spi_reverse()
110 /* Read DSP address space using SPI. addr and len have to be 4-byte aligned. */
124 		return -ENODEV;  in rt5677_spi_read()
126 	if ((addr & 3) || (len & 3)) {  in rt5677_spi_read()
127 		dev_err(&g_spi->dev, "Bad read align 0x%x(%zu)\n", addr, len);  in rt5677_spi_read()
128 		return -EACCES;  in rt5677_spi_read()
141 				len - offset, &t[1].len);  in rt5677_spi_read()
143 		/* Construct SPI message header */  in rt5677_spi_read()
147 		header[3] = ((addr + offset) & 0x0000ff00) >> 8;  in rt5677_spi_read()
156 		rt5677_spi_reverse(cb + offset, len - offset, body, t[1].len);  in rt5677_spi_read()
162 /* Write DSP address space using SPI. addr has to be 4-byte aligned.
163  * If len is not 4-byte aligned, then extra zeros are written at the end
179 		return -ENODEV;  in rt5677_spi_write()
181 	if (addr & 3) {  in rt5677_spi_write()
182 		dev_err(&g_spi->dev, "Bad write align 0x%x(%zu)\n", addr, len);  in rt5677_spi_write()
183 		return -EACCES;  in rt5677_spi_write()
193 				len - offset, &t.len);  in rt5677_spi_write()
195 		/* Construct SPI message header */  in rt5677_spi_write()
199 		buf[3] = ((addr + offset) & 0x0000ff00) >> 8;  in rt5677_spi_write()
203 		rt5677_spi_reverse(body, t.len, cb + offset, len - offset);  in rt5677_spi_write()
217 	return rt5677_spi_write(addr, fw->data, fw->size);  in rt5677_spi_write_firmware()
221 static int rt5677_spi_probe(struct spi_device *spi)  in rt5677_spi_probe()  argument
223 	g_spi = spi;  in rt5677_spi_probe()
242 MODULE_DESCRIPTION("ASoC RT5677 SPI driver");