From: Geert Uytterhoeven <[email protected]> Add support for specifying loopback mode for RSPI only, based on the SDK reference code.
Signed-off-by: Geert Uytterhoeven <[email protected]> --- V2: - No changes drivers/spi/spi-rspi.c | 59 +++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 48 insertions(+), 11 deletions(-) diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c index 4b25c8617b02..04d512e1e894 100644 --- a/drivers/spi/spi-rspi.c +++ b/drivers/spi/spi-rspi.c @@ -170,8 +170,8 @@ #define SPCMD_CPHA 0x0001 /* Clock Phase Setting */ /* SPBFCR - Buffer Control Register */ -#define SPBFCR_TXRST 0x80 /* Transmit Buffer Data Reset (qspi only) */ -#define SPBFCR_RXRST 0x40 /* Receive Buffer Data Reset (qspi only) */ +#define SPBFCR_TXRST 0x80 /* Transmit Buffer Data Reset */ +#define SPBFCR_RXRST 0x40 /* Receive Buffer Data Reset */ #define SPBFCR_TXTRG_MASK 0x30 /* Transmit Buffer Data Triggering Number */ #define SPBFCR_RXTRG_MASK 0x07 /* Receive Buffer Data Triggering Number */ @@ -188,6 +188,7 @@ struct rspi_data { spinlock_t lock; struct clk *clk; u8 spsr; + u8 sppcr; u8 spdcr; u8 data_width; u16 spcmd; @@ -256,7 +257,7 @@ struct spi_ops { struct spi_transfer *t); int (*receive_pio)(struct rspi_data *rspi, struct spi_message *mesg, struct spi_transfer *t); - + u16 mode_bits; }; /* @@ -317,8 +318,8 @@ static int rspi_set_config_register(const struct rspi_data *rspi, { int spbr; - /* Sets output mode(CMOS) and MOSI signal(from previous transfer) */ - rspi_write8(rspi, 0x00, RSPI_SPPCR); + /* Sets output mode */ + rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR); /* Sets transfer bit rate */ spbr = clk_get_rate(rspi->clk) / (2 * rspi->max_speed_hz) - 1; @@ -369,8 +370,8 @@ static int qspi_set_config_register(const struct rspi_data *rspi, u16 spcmd; int spbr; - /* Sets output mode(CMOS) and MOSI signal(from previous transfer) */ - rspi_write8(rspi, 0x00, RSPI_SPPCR); + /* Sets output mode */ + rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR); /* Sets transfer bit rate */ spbr = clk_get_rate(rspi->clk) / (2 * rspi->max_speed_hz); @@ -413,6 +414,21 @@ static int qspi_set_config_register(const struct rspi_data *rspi, #define set_config_register(spi, n) spi->ops->set_config_register(spi, n) +static void rspi_clear_rxbuf(struct rspi_data *rspi) +{ + rspi_write8(rspi, rspi_read8(rspi, RSPI_SPBFCR) | SPBFCR_RXRST, + RSPI_SPBFCR); + rspi_write8(rspi, rspi_read8(rspi, RSPI_SPBFCR) & (~SPBFCR_RXRST), + RSPI_SPBFCR); +} +static void rspi_clear_txbuf(struct rspi_data *rspi) +{ + rspi_write8(rspi, rspi_read8(rspi, RSPI_SPBFCR) | SPBFCR_TXRST, + RSPI_SPBFCR); + rspi_write8(rspi, rspi_read8(rspi, RSPI_SPBFCR) & (~SPBFCR_TXRST), + RSPI_SPBFCR); +} + static void rspi_enable_irq(const struct rspi_data *rspi, u8 enable) { rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | enable, RSPI_SPCR); @@ -452,6 +468,13 @@ static int rspi_send_pio(struct rspi_data *rspi, struct spi_message *mesg, { int remain = t->len; const u8 *data = t->tx_buf; + + if (rspi->sppcr & SPPCR_SPLP) { + /* loopback mode */ + rspi_clear_txbuf(rspi); + rspi_clear_rxbuf(rspi); + } + while (remain > 0) { rspi_set_txmode(rspi); @@ -461,7 +484,8 @@ static int rspi_send_pio(struct rspi_data *rspi, struct spi_message *mesg, return -ETIMEDOUT; } - if (!rspi->txmode && remain != t->len) { + if (!rspi->txmode && remain != t->len && + !(rspi->sppcr & SPPCR_SPLP)) { if (rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE) < 0) { dev_err(&rspi->master->dev, @@ -478,7 +502,7 @@ static int rspi_send_pio(struct rspi_data *rspi, struct spi_message *mesg, /* Waiting for the last transmition */ rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE); - if (!rspi->txmode) { + if (!rspi->txmode && !(rspi->sppcr & SPPCR_SPLP)) { if (rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE) < 0) { dev_err(&rspi->master->dev, "%s: receive timeout\n", __func__); @@ -651,7 +675,7 @@ static void rspi_receive_init(const struct rspi_data *rspi) u8 spsr; spsr = rspi_read8(rspi, RSPI_SPSR); - if (spsr & SPSR_SPRF) + if (spsr & SPSR_SPRF && !(rspi->sppcr & SPPCR_SPLP)) rspi_read_data(rspi); /* dummy read */ if (spsr & SPSR_OVRF) rspi_write8(rspi, rspi_read8(rspi, RSPI_SPSR) & ~SPSR_OVRF, @@ -689,6 +713,12 @@ static int rspi_receive_pio(struct rspi_data *rspi, struct spi_message *mesg, remain--; } + if (rspi->sppcr & SPPCR_SPLP) { + /* loopback mode */ + rspi_clear_txbuf(rspi); + rspi_clear_rxbuf(rspi); + } + return 0; } @@ -918,6 +948,11 @@ static int rspi_setup(struct spi_device *spi) if (spi->mode & SPI_CPHA) rspi->spcmd |= SPCMD_CPHA; + /* CMOS output mode and MOSI signal from previous transfer */ + rspi->sppcr = 0; + if (spi->mode & SPI_LOOP) + rspi->sppcr |= SPPCR_SPLP; + set_config_register(rspi, 8); return 0; @@ -1095,7 +1130,7 @@ static int rspi_probe(struct platform_device *pdev) master->setup = rspi_setup; master->transfer = rspi_transfer; master->cleanup = rspi_cleanup; - master->mode_bits = SPI_CPHA | SPI_CPOL; + master->mode_bits = ops->mode_bits; ret = ops->parse_platform_data(rspi, rspi_pd); if (ret < 0) { @@ -1151,6 +1186,7 @@ static struct spi_ops rspi_ops = { .set_config_register = rspi_set_config_register, .send_pio = rspi_send_pio, .receive_pio = rspi_receive_pio, + .mode_bits = SPI_CPHA | SPI_CPOL | SPI_LOOP, }; static struct spi_ops qspi_ops = { @@ -1158,6 +1194,7 @@ static struct spi_ops qspi_ops = { .set_config_register = qspi_set_config_register, .send_pio = qspi_send_pio, .receive_pio = qspi_receive_pio, + .mode_bits = SPI_CPHA | SPI_CPOL, }; static struct platform_device_id spi_driver_ids[] = { -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
