v4.19.13 snapshot.
diff --git a/sound/soc/codecs/rt5677-spi.c b/sound/soc/codecs/rt5677-spi.c
new file mode 100644
index 0000000..bd51f36
--- /dev/null
+++ b/sound/soc/codecs/rt5677-spi.c
@@ -0,0 +1,240 @@
+/*
+ * rt5677-spi.c  --  RT5677 ALSA SoC audio codec driver
+ *
+ * Copyright 2013 Realtek Semiconductor Corp.
+ * Author: Oder Chiou <oder_chiou@realtek.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/spi/spi.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/sched.h>
+#include <linux/uaccess.h>
+#include <linux/regulator/consumer.h>
+#include <linux/pm_qos.h>
+#include <linux/sysfs.h>
+#include <linux/clk.h>
+#include <linux/firmware.h>
+
+#include "rt5677-spi.h"
+
+#define RT5677_SPI_BURST_LEN	240
+#define RT5677_SPI_HEADER	5
+#define RT5677_SPI_FREQ		6000000
+
+/* The AddressPhase and DataPhase of SPI commands are MSB first on the wire.
+ * DataPhase word size of 16-bit commands is 2 bytes.
+ * DataPhase word size of 32-bit commands is 4 bytes.
+ * DataPhase word size of burst commands is 8 bytes.
+ * The DSP CPU is little-endian.
+ */
+#define RT5677_SPI_WRITE_BURST	0x5
+#define RT5677_SPI_READ_BURST	0x4
+#define RT5677_SPI_WRITE_32	0x3
+#define RT5677_SPI_READ_32	0x2
+#define RT5677_SPI_WRITE_16	0x1
+#define RT5677_SPI_READ_16	0x0
+
+static struct spi_device *g_spi;
+static DEFINE_MUTEX(spi_mutex);
+
+/* Select a suitable transfer command for the next transfer to ensure
+ * the transfer address is always naturally aligned while minimizing
+ * the total number of transfers required.
+ *
+ * 3 transfer commands are available:
+ * RT5677_SPI_READ/WRITE_16:	Transfer 2 bytes
+ * RT5677_SPI_READ/WRITE_32:	Transfer 4 bytes
+ * RT5677_SPI_READ/WRITE_BURST:	Transfer any multiples of 8 bytes
+ *
+ * For example, reading 260 bytes at 0x60030002 uses the following commands:
+ * 0x60030002 RT5677_SPI_READ_16	2 bytes
+ * 0x60030004 RT5677_SPI_READ_32	4 bytes
+ * 0x60030008 RT5677_SPI_READ_BURST	240 bytes
+ * 0x600300F8 RT5677_SPI_READ_BURST	8 bytes
+ * 0x60030100 RT5677_SPI_READ_32	4 bytes
+ * 0x60030104 RT5677_SPI_READ_16	2 bytes
+ *
+ * Input:
+ * @read: true for read commands; false for write commands
+ * @align: alignment of the next transfer address
+ * @remain: number of bytes remaining to transfer
+ *
+ * Output:
+ * @len: number of bytes to transfer with the selected command
+ * Returns the selected command
+ */
+static u8 rt5677_spi_select_cmd(bool read, u32 align, u32 remain, u32 *len)
+{
+	u8 cmd;
+
+	if (align == 2 || align == 6 || remain == 2) {
+		cmd = RT5677_SPI_READ_16;
+		*len = 2;
+	} else if (align == 4 || remain <= 6) {
+		cmd = RT5677_SPI_READ_32;
+		*len = 4;
+	} else {
+		cmd = RT5677_SPI_READ_BURST;
+		*len = min_t(u32, remain & ~7, RT5677_SPI_BURST_LEN);
+	}
+	return read ? cmd : cmd + 1;
+}
+
+/* Copy dstlen bytes from src to dst, while reversing byte order for each word.
+ * If srclen < dstlen, zeros are padded.
+ */
+static void rt5677_spi_reverse(u8 *dst, u32 dstlen, const u8 *src, u32 srclen)
+{
+	u32 w, i, si;
+	u32 word_size = min_t(u32, dstlen, 8);
+
+	for (w = 0; w < dstlen; w += word_size) {
+		for (i = 0; i < word_size; i++) {
+			si = w + word_size - i - 1;
+			dst[w + i] = si < srclen ? src[si] : 0;
+		}
+	}
+}
+
+/* Read DSP address space using SPI. addr and len have to be 2-byte aligned. */
+int rt5677_spi_read(u32 addr, void *rxbuf, size_t len)
+{
+	u32 offset;
+	int status = 0;
+	struct spi_transfer t[2];
+	struct spi_message m;
+	/* +4 bytes is for the DummyPhase following the AddressPhase */
+	u8 header[RT5677_SPI_HEADER + 4];
+	u8 body[RT5677_SPI_BURST_LEN];
+	u8 spi_cmd;
+	u8 *cb = rxbuf;
+
+	if (!g_spi)
+		return -ENODEV;
+
+	if ((addr & 1) || (len & 1)) {
+		dev_err(&g_spi->dev, "Bad read align 0x%x(%zu)\n", addr, len);
+		return -EACCES;
+	}
+
+	memset(t, 0, sizeof(t));
+	t[0].tx_buf = header;
+	t[0].len = sizeof(header);
+	t[0].speed_hz = RT5677_SPI_FREQ;
+	t[1].rx_buf = body;
+	t[1].speed_hz = RT5677_SPI_FREQ;
+	spi_message_init_with_transfers(&m, t, ARRAY_SIZE(t));
+
+	for (offset = 0; offset < len; offset += t[1].len) {
+		spi_cmd = rt5677_spi_select_cmd(true, (addr + offset) & 7,
+				len - offset, &t[1].len);
+
+		/* Construct SPI message header */
+		header[0] = spi_cmd;
+		header[1] = ((addr + offset) & 0xff000000) >> 24;
+		header[2] = ((addr + offset) & 0x00ff0000) >> 16;
+		header[3] = ((addr + offset) & 0x0000ff00) >> 8;
+		header[4] = ((addr + offset) & 0x000000ff) >> 0;
+
+		mutex_lock(&spi_mutex);
+		status |= spi_sync(g_spi, &m);
+		mutex_unlock(&spi_mutex);
+
+		/* Copy data back to caller buffer */
+		rt5677_spi_reverse(cb + offset, t[1].len, body, t[1].len);
+	}
+	return status;
+}
+EXPORT_SYMBOL_GPL(rt5677_spi_read);
+
+/* Write DSP address space using SPI. addr has to be 2-byte aligned.
+ * If len is not 2-byte aligned, an extra byte of zero is written at the end
+ * as padding.
+ */
+int rt5677_spi_write(u32 addr, const void *txbuf, size_t len)
+{
+	u32 offset, len_with_pad = len;
+	int status = 0;
+	struct spi_transfer t;
+	struct spi_message m;
+	/* +1 byte is for the DummyPhase following the DataPhase */
+	u8 buf[RT5677_SPI_HEADER + RT5677_SPI_BURST_LEN + 1];
+	u8 *body = buf + RT5677_SPI_HEADER;
+	u8 spi_cmd;
+	const u8 *cb = txbuf;
+
+	if (!g_spi)
+		return -ENODEV;
+
+	if (addr & 1) {
+		dev_err(&g_spi->dev, "Bad write align 0x%x(%zu)\n", addr, len);
+		return -EACCES;
+	}
+
+	if (len & 1)
+		len_with_pad = len + 1;
+
+	memset(&t, 0, sizeof(t));
+	t.tx_buf = buf;
+	t.speed_hz = RT5677_SPI_FREQ;
+	spi_message_init_with_transfers(&m, &t, 1);
+
+	for (offset = 0; offset < len_with_pad;) {
+		spi_cmd = rt5677_spi_select_cmd(false, (addr + offset) & 7,
+				len_with_pad - offset, &t.len);
+
+		/* Construct SPI message header */
+		buf[0] = spi_cmd;
+		buf[1] = ((addr + offset) & 0xff000000) >> 24;
+		buf[2] = ((addr + offset) & 0x00ff0000) >> 16;
+		buf[3] = ((addr + offset) & 0x0000ff00) >> 8;
+		buf[4] = ((addr + offset) & 0x000000ff) >> 0;
+
+		/* Fetch data from caller buffer */
+		rt5677_spi_reverse(body, t.len, cb + offset, len - offset);
+		offset += t.len;
+		t.len += RT5677_SPI_HEADER + 1;
+
+		mutex_lock(&spi_mutex);
+		status |= spi_sync(g_spi, &m);
+		mutex_unlock(&spi_mutex);
+	}
+	return status;
+}
+EXPORT_SYMBOL_GPL(rt5677_spi_write);
+
+int rt5677_spi_write_firmware(u32 addr, const struct firmware *fw)
+{
+	return rt5677_spi_write(addr, fw->data, fw->size);
+}
+EXPORT_SYMBOL_GPL(rt5677_spi_write_firmware);
+
+static int rt5677_spi_probe(struct spi_device *spi)
+{
+	g_spi = spi;
+	return 0;
+}
+
+static struct spi_driver rt5677_spi_driver = {
+	.driver = {
+		.name = "rt5677",
+	},
+	.probe = rt5677_spi_probe,
+};
+module_spi_driver(rt5677_spi_driver);
+
+MODULE_DESCRIPTION("ASoC RT5677 SPI driver");
+MODULE_AUTHOR("Oder Chiou <oder_chiou@realtek.com>");
+MODULE_LICENSE("GPL v2");