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path: root/drivers/spi/spi-fsl-espi.c
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Diffstat (limited to 'drivers/spi/spi-fsl-espi.c')
-rw-r--r--drivers/spi/spi-fsl-espi.c68
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);