diff options
Diffstat (limited to 'sound/soc/codecs/rt5677-spi.c')
| -rw-r--r-- | sound/soc/codecs/rt5677-spi.c | 233 |
1 files changed, 173 insertions, 60 deletions
diff --git a/sound/soc/codecs/rt5677-spi.c b/sound/soc/codecs/rt5677-spi.c index ef6348cb9..3505aafba 100644 --- a/sound/soc/codecs/rt5677-spi.c +++ b/sound/soc/codecs/rt5677-spi.c @@ -31,84 +31,197 @@ #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); -/** - * rt5677_spi_write - Write data to SPI. - * @txbuf: Data Buffer for writing. - * @len: Data length. +/* 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 * - * Returns true for success. + * Output: + * @len: number of bytes to transfer with the selected command + * Returns the selected command */ -int rt5677_spi_write(u8 *txbuf, size_t len) +static u8 rt5677_spi_select_cmd(bool read, u32 align, u32 remain, u32 *len) { - int status; - - status = spi_write(g_spi, txbuf, len); - - if (status) - dev_err(&g_spi->dev, "rt5677_spi_write error %d\n", status); - - return status; + 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; } -EXPORT_SYMBOL_GPL(rt5677_spi_write); -/** - * rt5677_spi_burst_write - Write data to SPI by rt5677 dsp memory address. - * @addr: Start address. - * @txbuf: Data Buffer for writng. - * @len: Data length, it must be a multiple of 8. - * - * - * Returns true for success. +/* Copy dstlen bytes from src to dst, while reversing byte order for each word. + * If srclen < dstlen, zeros are padded. */ -int rt5677_spi_burst_write(u32 addr, const struct firmware *fw) +static void rt5677_spi_reverse(u8 *dst, u32 dstlen, const u8 *src, u32 srclen) { - u8 spi_cmd = RT5677_SPI_CMD_BURST_WRITE; - u8 *write_buf; - unsigned int i, end, offset = 0; - - write_buf = kmalloc(RT5677_SPI_BUF_LEN + 6, GFP_KERNEL); - - if (write_buf == NULL) - return -ENOMEM; - - while (offset < fw->size) { - if (offset + RT5677_SPI_BUF_LEN <= fw->size) - end = RT5677_SPI_BUF_LEN; - else - end = fw->size % RT5677_SPI_BUF_LEN; - - write_buf[0] = spi_cmd; - write_buf[1] = ((addr + offset) & 0xff000000) >> 24; - write_buf[2] = ((addr + offset) & 0x00ff0000) >> 16; - write_buf[3] = ((addr + offset) & 0x0000ff00) >> 8; - write_buf[4] = ((addr + offset) & 0x000000ff) >> 0; - - for (i = 0; i < end; i += 8) { - write_buf[i + 12] = fw->data[offset + i + 0]; - write_buf[i + 11] = fw->data[offset + i + 1]; - write_buf[i + 10] = fw->data[offset + i + 2]; - write_buf[i + 9] = fw->data[offset + i + 3]; - write_buf[i + 8] = fw->data[offset + i + 4]; - write_buf[i + 7] = fw->data[offset + i + 5]; - write_buf[i + 6] = fw->data[offset + i + 6]; - write_buf[i + 5] = fw->data[offset + i + 7]; + 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; } + } +} - write_buf[end + 5] = spi_cmd; +/* 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; + } - rt5677_spi_write(write_buf, end + 6); + 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); - offset += RT5677_SPI_BUF_LEN; +/* 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; } - kfree(write_buf); + 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); - return 0; +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_burst_write); +EXPORT_SYMBOL_GPL(rt5677_spi_write_firmware); static int rt5677_spi_probe(struct spi_device *spi) { |