diff options
Diffstat (limited to 'drivers/spi/spi-fsl-espi.c')
| -rw-r--r-- | drivers/spi/spi-fsl-espi.c | 68 |
1 files changed, 42 insertions, 26 deletions
diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c index f04c2464e854..95c1fbfe1cbe 100644 --- a/drivers/spi/spi-fsl-espi.c +++ b/drivers/spi/spi-fsl-espi.c @@ -54,6 +54,8 @@ #define CSMODE_AFT(x) ((x) << 8) #define CSMODE_CG(x) ((x) << 3) +#define FSL_ESPI_FIFO_SIZE 32 + /* Default mode/csmode for eSPI controller */ #define SPMODE_INIT_VAL (SPMODE_TXTHR(4) | SPMODE_RXTHR(3)) #define CSMODE_INIT_VAL (CSMODE_POL_1 | CSMODE_BEF(0) \ @@ -200,6 +202,27 @@ static int fsl_espi_check_message(struct spi_message *m) return 0; } +static void fsl_espi_fill_tx_fifo(struct mpc8xxx_spi *mspi, u32 events) +{ + u32 tx_fifo_avail; + + /* if events is zero transfer has not started and tx fifo is empty */ + tx_fifo_avail = events ? SPIE_TXCNT(events) : FSL_ESPI_FIFO_SIZE; + + while (tx_fifo_avail >= min(4U, mspi->tx_len) && mspi->tx_len) + if (mspi->tx_len >= 4) { + fsl_espi_write_reg(mspi, ESPI_SPITF, *(u32 *)mspi->tx); + mspi->tx += 4; + mspi->tx_len -= 4; + tx_fifo_avail -= 4; + } else { + fsl_espi_write_reg8(mspi, ESPI_SPITF, *(u8 *)mspi->tx); + mspi->tx += 1; + mspi->tx_len -= 1; + tx_fifo_avail -= 1; + } +} + static void fsl_espi_change_mode(struct spi_device *spi) { struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master); @@ -262,7 +285,7 @@ static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t) int ret; mpc8xxx_spi->len = t->len; - mpc8xxx_spi->count = roundup(t->len, 4) / 4; + mpc8xxx_spi->tx_len = t->len; mpc8xxx_spi->tx = t->tx_buf; mpc8xxx_spi->rx = t->rx_buf; @@ -276,21 +299,22 @@ static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t) /* enable rx ints */ fsl_espi_write_reg(mpc8xxx_spi, ESPI_SPIM, SPIM_RNE); - /* transmit word */ - fsl_espi_write_reg(mpc8xxx_spi, ESPI_SPITF, *(u32 *)mpc8xxx_spi->tx); - mpc8xxx_spi->tx += 4; + /* Prevent filling the fifo from getting interrupted */ + spin_lock_irq(&mpc8xxx_spi->lock); + fsl_espi_fill_tx_fifo(mpc8xxx_spi, 0); + spin_unlock_irq(&mpc8xxx_spi->lock); /* Won't hang up forever, SPI bus sometimes got lost interrupts... */ ret = wait_for_completion_timeout(&mpc8xxx_spi->done, 2 * HZ); if (ret == 0) dev_err(mpc8xxx_spi->dev, - "Transaction hanging up (left %d bytes)\n", - mpc8xxx_spi->count); + "Transaction hanging up (left %u bytes)\n", + mpc8xxx_spi->tx_len); /* disable rx ints */ fsl_espi_write_reg(mpc8xxx_spi, ESPI_SPIM, 0); - return mpc8xxx_spi->count > 0 ? -EMSGSIZE : 0; + return mpc8xxx_spi->tx_len > 0 ? -EMSGSIZE : 0; } static int fsl_espi_trans(struct spi_message *m, struct spi_transfer *trans) @@ -461,26 +485,11 @@ static void fsl_espi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events) } } - if (!(events & SPIE_TNF)) { - int ret; - - /* spin until TX is done */ - ret = spin_event_timeout(((events = fsl_espi_read_reg( - mspi, ESPI_SPIE)) & SPIE_TNF), 1000, 0); - if (!ret) { - dev_err(mspi->dev, "tired waiting for SPIE_TNF\n"); - complete(&mspi->done); - return; - } - } + if (mspi->tx_len) + fsl_espi_fill_tx_fifo(mspi, events); - mspi->count -= 1; - if (mspi->count) { - fsl_espi_write_reg(mspi, ESPI_SPITF, *(u32 *)mspi->tx); - mspi->tx += 4; - } else { + if (!mspi->tx_len && !mspi->len) complete(&mspi->done); - } } static irqreturn_t fsl_espi_irq(s32 irq, void *context_data) @@ -488,10 +497,14 @@ static irqreturn_t fsl_espi_irq(s32 irq, void *context_data) struct mpc8xxx_spi *mspi = context_data; u32 events; + spin_lock(&mspi->lock); + /* Get interrupt events(tx/rx) */ events = fsl_espi_read_reg(mspi, ESPI_SPIE); - if (!events) + if (!events) { + spin_unlock_irq(&mspi->lock); return IRQ_NONE; + } dev_vdbg(mspi->dev, "%s: events %x\n", __func__, events); @@ -500,6 +513,8 @@ static irqreturn_t fsl_espi_irq(s32 irq, void *context_data) /* Clear the events */ fsl_espi_write_reg(mspi, ESPI_SPIE, events); + spin_unlock(&mspi->lock); + return IRQ_HANDLED; } @@ -562,6 +577,7 @@ static int fsl_espi_probe(struct device *dev, struct resource *mem, master->max_message_size = fsl_espi_max_message_size; mpc8xxx_spi = spi_master_get_devdata(master); + spin_lock_init(&mpc8xxx_spi->lock); mpc8xxx_spi->local_buf = devm_kmalloc(dev, SPCOM_TRANLEN_MAX, GFP_KERNEL); |