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author | Geert Uytterhoeven <geert+renesas@linux-m68k.org> | 2014-01-30 09:43:50 +0100 |
---|---|---|
committer | Mark Brown <broonie@linaro.org> | 2014-01-30 16:51:21 +0000 |
commit | 880c6d114fd79a6973708744c78c7f55da6aea4c (patch) | |
tree | 061174d839c9edb06c5df3bfd13471b9fc3c3a26 /drivers/spi/spi-rspi.c | |
parent | 426ef76dd8a394a0e04d096941cd9acb49539a3e (diff) | |
download | linux-stable-880c6d114fd79a6973708744c78c7f55da6aea4c.tar.gz linux-stable-880c6d114fd79a6973708744c78c7f55da6aea4c.tar.bz2 linux-stable-880c6d114fd79a6973708744c78c7f55da6aea4c.zip |
spi: rspi: Add support for Quad and Dual SPI Transfers on QSPI
Add support for Quad and Dual SPI Transfers on the Renesas Quad Serial
Peripheral Interface, as found in R-Car Gen2 SoCs like R-Car H2 (r8a7790)
and R-Car M2 (r8a7791):
- Add unidirectional transfer methods for Quad/Dual SPI Transfers.
- Program the sequencer to handle SPI messages with multiple transfer
modes when Quad or Dual transfers are enabled for an SPI slave.
Up to 4 transfer modes per SPI message are supported by the hardware.
- Advertise the availability of Quad and Dual SPI modes on QSPI.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
Diffstat (limited to 'drivers/spi/spi-rspi.c')
-rw-r--r-- | drivers/spi/spi-rspi.c | 162 |
1 files changed, 148 insertions, 14 deletions
diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c index e56fcb5f7f99..34ad4bca8a41 100644 --- a/drivers/spi/spi-rspi.c +++ b/drivers/spi/spi-rspi.c @@ -2,6 +2,7 @@ * SH RSPI driver * * Copyright (C) 2012, 2013 Renesas Solutions Corp. + * Copyright (C) 2014 Glider bvba * * Based on spi-sh.c: * Copyright (C) 2011 Renesas Solutions Corp. @@ -57,6 +58,10 @@ #define RSPI_SPCMD5 0x1a /* Command Register 5 */ #define RSPI_SPCMD6 0x1c /* Command Register 6 */ #define RSPI_SPCMD7 0x1e /* Command Register 7 */ +#define RSPI_SPCMD(i) (RSPI_SPCMD0 + (i) * 2) +#define RSPI_NUM_SPCMD 8 +#define RSPI_RZ_NUM_SPCMD 4 +#define QSPI_NUM_SPCMD 4 /* RSPI on RZ only */ #define RSPI_SPBFCR 0x20 /* Buffer Control Register */ @@ -69,6 +74,7 @@ #define QSPI_SPBMUL1 0x20 /* Transfer Data Length Multiplier Setting Register 1 */ #define QSPI_SPBMUL2 0x24 /* Transfer Data Length Multiplier Setting Register 2 */ #define QSPI_SPBMUL3 0x28 /* Transfer Data Length Multiplier Setting Register 3 */ +#define QSPI_SPBMUL(i) (QSPI_SPBMUL0 + (i) * 4) /* SPCR - Control Register */ #define SPCR_SPRIE 0x80 /* Receive Interrupt Enable */ @@ -152,7 +158,7 @@ #define SPCMD_LSBF 0x1000 /* LSB First */ #define SPCMD_SPB_MASK 0x0f00 /* Data Length Setting */ #define SPCMD_SPB_8_TO_16(bit) (((bit - 1) << 8) & SPCMD_SPB_MASK) -#define SPCMD_SPB_8BIT 0x0000 /* qspi only */ +#define SPCMD_SPB_8BIT 0x0000 /* QSPI only */ #define SPCMD_SPB_16BIT 0x0100 #define SPCMD_SPB_20BIT 0x0000 #define SPCMD_SPB_24BIT 0x0100 @@ -245,6 +251,7 @@ struct spi_ops { int (*set_config_register)(struct rspi_data *rspi, int access_size); int (*transfer_one)(struct spi_master *master, struct spi_device *spi, struct spi_transfer *xfer); + u16 mode_bits; }; /* @@ -274,8 +281,8 @@ static int rspi_set_config_register(struct rspi_data *rspi, int access_size) rspi_write8(rspi, 0x00, RSPI_SPCR2); /* Sets SPCMD */ - rspi_write16(rspi, SPCMD_SPB_8_TO_16(access_size) | rspi->spcmd, - RSPI_SPCMD0); + rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size); + rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0); /* Sets RSPI mode */ rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR); @@ -321,7 +328,6 @@ static int rspi_rz_set_config_register(struct rspi_data *rspi, int access_size) */ static int qspi_set_config_register(struct rspi_data *rspi, int access_size) { - u16 spcmd; int spbr; /* Sets output mode, MOSI signal, and (optionally) loopback */ @@ -342,13 +348,13 @@ static int qspi_set_config_register(struct rspi_data *rspi, int access_size) /* Data Length Setting */ if (access_size == 8) - spcmd = SPCMD_SPB_8BIT; + rspi->spcmd |= SPCMD_SPB_8BIT; else if (access_size == 16) - spcmd = SPCMD_SPB_16BIT; + rspi->spcmd |= SPCMD_SPB_16BIT; else - spcmd = SPCMD_SPB_32BIT; + rspi->spcmd |= SPCMD_SPB_32BIT; - spcmd |= SPCMD_SCKDEN | SPCMD_SLNDEN | rspi->spcmd | SPCMD_SPNDEN; + rspi->spcmd |= SPCMD_SCKDEN | SPCMD_SLNDEN | SPCMD_SPNDEN; /* Resets transfer data length */ rspi_write32(rspi, 0, QSPI_SPBMUL0); @@ -359,9 +365,9 @@ static int qspi_set_config_register(struct rspi_data *rspi, int access_size) rspi_write8(rspi, 0x00, QSPI_SPBFCR); /* Sets SPCMD */ - rspi_write16(rspi, spcmd, RSPI_SPCMD0); + rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0); - /* Enables SPI function in a master mode */ + /* Enables SPI function in master mode */ rspi_write8(rspi, SPCR_SPE | SPCR_MSTR, RSPI_SPCR); return 0; @@ -811,12 +817,55 @@ static int qspi_transfer_out_in(struct rspi_data *rspi, return 0; } +static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer) +{ + const u8 *buf = xfer->tx_buf; + unsigned int i; + int ret; + + for (i = 0; i < xfer->len; i++) { + ret = rspi_data_out(rspi, *buf++); + if (ret < 0) + return ret; + } + + /* Wait for the last transmission */ + rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE); + + return 0; +} + +static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer) +{ + u8 *buf = xfer->rx_buf; + unsigned int i; + int ret; + + for (i = 0; i < xfer->len; i++) { + ret = rspi_data_in(rspi); + if (ret < 0) + return ret; + *buf++ = ret; + } + + return 0; +} + static int qspi_transfer_one(struct spi_master *master, struct spi_device *spi, struct spi_transfer *xfer) { struct rspi_data *rspi = spi_master_get_devdata(master); - return qspi_transfer_out_in(rspi, xfer); + if (xfer->tx_buf && xfer->tx_nbits > SPI_NBITS_SINGLE) { + /* Quad or Dual SPI Write */ + return qspi_transfer_out(rspi, xfer); + } else if (xfer->rx_buf && xfer->rx_nbits > SPI_NBITS_SINGLE) { + /* Quad or Dual SPI Read */ + return qspi_transfer_in(rspi, xfer); + } else { + /* Single SPI Transfer */ + return qspi_transfer_out_in(rspi, xfer); + } } static int rspi_setup(struct spi_device *spi) @@ -845,21 +894,101 @@ static void rspi_cleanup(struct spi_device *spi) { } +static u16 qspi_transfer_mode(const struct spi_transfer *xfer) +{ + if (xfer->tx_buf) + switch (xfer->tx_nbits) { + case SPI_NBITS_QUAD: + return SPCMD_SPIMOD_QUAD; + case SPI_NBITS_DUAL: + return SPCMD_SPIMOD_DUAL; + default: + return 0; + } + if (xfer->rx_buf) + switch (xfer->rx_nbits) { + case SPI_NBITS_QUAD: + return SPCMD_SPIMOD_QUAD | SPCMD_SPRW; + case SPI_NBITS_DUAL: + return SPCMD_SPIMOD_DUAL | SPCMD_SPRW; + default: + return 0; + } + + return 0; +} + +static int qspi_setup_sequencer(struct rspi_data *rspi, + const struct spi_message *msg) +{ + const struct spi_transfer *xfer; + unsigned int i = 0, len = 0; + u16 current_mode = 0xffff, mode; + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + mode = qspi_transfer_mode(xfer); + if (mode == current_mode) { + len += xfer->len; + continue; + } + + /* Transfer mode change */ + if (i) { + /* Set transfer data length of previous transfer */ + rspi_write32(rspi, len, QSPI_SPBMUL(i - 1)); + } + + if (i >= QSPI_NUM_SPCMD) { + dev_err(&msg->spi->dev, + "Too many different transfer modes"); + return -EINVAL; + } + + /* Program transfer mode for this transfer */ + rspi_write16(rspi, rspi->spcmd | mode, RSPI_SPCMD(i)); + current_mode = mode; + len = xfer->len; + i++; + } + if (i) { + /* Set final transfer data length and sequence length */ + rspi_write32(rspi, len, QSPI_SPBMUL(i - 1)); + rspi_write8(rspi, i - 1, RSPI_SPSCR); + } + + return 0; +} + static int rspi_prepare_message(struct spi_master *master, - struct spi_message *message) + struct spi_message *msg) { struct rspi_data *rspi = spi_master_get_devdata(master); + int ret; + if (msg->spi->mode & + (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)) { + /* Setup sequencer for messages with multiple transfer modes */ + ret = qspi_setup_sequencer(rspi, msg); + if (ret < 0) + return ret; + } + + /* Enable SPI function in master mode */ rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_SPE, RSPI_SPCR); return 0; } static int rspi_unprepare_message(struct spi_master *master, - struct spi_message *message) + struct spi_message *msg) { struct rspi_data *rspi = spi_master_get_devdata(master); + /* Disable SPI function */ rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_SPE, RSPI_SPCR); + + /* Reset sequencer for Single SPI Transfers */ + rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0); + rspi_write8(rspi, 0, RSPI_SPSCR); return 0; } @@ -989,16 +1118,21 @@ static int rspi_remove(struct platform_device *pdev) static const struct spi_ops rspi_ops = { .set_config_register = rspi_set_config_register, .transfer_one = rspi_transfer_one, + .mode_bits = SPI_CPHA | SPI_CPOL | SPI_LOOP, }; static const struct spi_ops rspi_rz_ops = { .set_config_register = rspi_rz_set_config_register, .transfer_one = rspi_rz_transfer_one, + .mode_bits = SPI_CPHA | SPI_CPOL | SPI_LOOP, }; static const struct spi_ops qspi_ops = { .set_config_register = qspi_set_config_register, .transfer_one = qspi_transfer_one, + .mode_bits = SPI_CPHA | SPI_CPOL | SPI_LOOP | + SPI_TX_DUAL | SPI_TX_QUAD | + SPI_RX_DUAL | SPI_RX_QUAD, }; #ifdef CONFIG_OF @@ -1120,7 +1254,7 @@ static int rspi_probe(struct platform_device *pdev) master->cleanup = rspi_cleanup; master->prepare_message = rspi_prepare_message; master->unprepare_message = rspi_unprepare_message; - master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LOOP; + master->mode_bits = ops->mode_bits; master->dev.of_node = pdev->dev.of_node; ret = platform_get_irq_byname(pdev, "rx"); |