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authorHeiner Kallweit <hkallweit1@gmail.com>2016-11-26 01:59:57 +0300
committerMark Brown <broonie@kernel.org>2016-11-30 21:05:14 +0300
commitdcb425f3ba6ebee4269f68461420246ba9d4ec02 (patch)
tree1c07bd6a287e00bd54b829d43d69b701eae92b01 /drivers/spi/spi-fsl-espi.c
parent05823432844515e6e6e0e80dd44624a36ea405b7 (diff)
downloadlinux-dcb425f3ba6ebee4269f68461420246ba9d4ec02.tar.xz
spi: fsl-espi: eliminate need for linearization when reading from hardware
Eliminate need for linearization when reading from the hardware and write to the transfer buffers directly. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-fsl-espi.c')
-rw-r--r--drivers/spi/spi-fsl-espi.c77
1 files changed, 63 insertions, 14 deletions
diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
index 189ab36b787f..e93892dca90a 100644
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -102,6 +102,9 @@ struct fsl_espi {
struct spi_transfer *tx_t;
unsigned int tx_pos;
bool tx_done;
+ struct spi_transfer *rx_t;
+ unsigned int rx_pos;
+ bool rx_done;
bool swab;
unsigned int rx_len;
@@ -125,6 +128,11 @@ static inline u32 fsl_espi_read_reg(struct fsl_espi *espi, int offset)
return ioread32be(espi->reg_base + offset);
}
+static inline u16 fsl_espi_read_reg16(struct fsl_espi *espi, int offset)
+{
+ return ioread16(espi->reg_base + offset);
+}
+
static inline u8 fsl_espi_read_reg8(struct fsl_espi *espi, int offset)
{
return ioread8(espi->reg_base + offset);
@@ -328,19 +336,53 @@ start:
static void fsl_espi_read_rx_fifo(struct fsl_espi *espi, u32 events)
{
u32 rx_fifo_avail = SPIE_RXCNT(events);
+ unsigned int rx_left;
+ void *rx_buf;
- while (rx_fifo_avail >= min(4U, espi->rx_len) && espi->rx_len)
- if (espi->rx_len >= 4) {
- *(u32 *)espi->rx = fsl_espi_read_reg(espi, ESPI_SPIRF);
- espi->rx += 4;
- espi->rx_len -= 4;
+start:
+ rx_left = espi->rx_t->len - espi->rx_pos;
+ rx_buf = espi->rx_t->rx_buf;
+ while (rx_fifo_avail >= min(4U, rx_left) && rx_left) {
+ if (rx_left >= 4) {
+ u32 val = fsl_espi_read_reg(espi, ESPI_SPIRF);
+
+ if (rx_buf && espi->swab)
+ *(u32 *)(rx_buf + espi->rx_pos) = swahb32(val);
+ else if (rx_buf)
+ *(u32 *)(rx_buf + espi->rx_pos) = val;
+ espi->rx_pos += 4;
+ rx_left -= 4;
rx_fifo_avail -= 4;
+ } else if (rx_left >= 2 && rx_buf && espi->swab) {
+ u16 val = fsl_espi_read_reg16(espi, ESPI_SPIRF);
+
+ *(u16 *)(rx_buf + espi->rx_pos) = swab16(val);
+ espi->rx_pos += 2;
+ rx_left -= 2;
+ rx_fifo_avail -= 2;
} else {
- *(u8 *)espi->rx = fsl_espi_read_reg8(espi, ESPI_SPIRF);
- espi->rx += 1;
- espi->rx_len -= 1;
+ u8 val = fsl_espi_read_reg8(espi, ESPI_SPIRF);
+
+ if (rx_buf)
+ *(u8 *)(rx_buf + espi->rx_pos) = val;
+ espi->rx_pos += 1;
+ rx_left -= 1;
rx_fifo_avail -= 1;
}
+ }
+
+ if (!rx_left) {
+ if (list_is_last(&espi->rx_t->transfer_list,
+ espi->m_transfers)) {
+ espi->rx_done = true;
+ return;
+ }
+ espi->rx_t = list_next_entry(espi->rx_t, transfer_list);
+ espi->rx_pos = 0;
+ /* continue with next transfer if rx fifo is not empty */
+ if (rx_fifo_avail)
+ goto start;
+ }
}
static void fsl_espi_setup_transfer(struct spi_device *spi,
@@ -375,6 +417,7 @@ static void fsl_espi_setup_transfer(struct spi_device *spi,
static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
{
struct fsl_espi *espi = spi_master_get_devdata(spi->master);
+ unsigned int rx_len = t->len;
u32 mask, spcom;
int ret;
@@ -395,6 +438,7 @@ static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
spcom |= SPCOM_RXSKIP(espi->rxskip);
espi->tx_len = espi->rxskip;
espi->rx_len = t->len - espi->rxskip;
+ rx_len = t->len - espi->rxskip;
espi->rx = t->rx_buf + espi->rxskip;
if (t->rx_nbits == SPI_NBITS_DUAL)
spcom |= SPCOM_DO;
@@ -404,7 +448,7 @@ static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
/* enable interrupts */
mask = SPIM_DON;
- if (espi->rx_len > FSL_ESPI_FIFO_SIZE)
+ if (rx_len > FSL_ESPI_FIFO_SIZE)
mask |= SPIM_RXT;
fsl_espi_write_reg(espi, ESPI_SPIM, mask);
@@ -438,6 +482,10 @@ static int fsl_espi_trans(struct spi_message *m, struct spi_transfer *trans)
transfer_list);
espi->tx_pos = 0;
espi->tx_done = false;
+ espi->rx_t = list_first_entry(&m->transfers, struct spi_transfer,
+ transfer_list);
+ espi->rx_pos = 0;
+ espi->rx_done = false;
espi->rxskip = fsl_espi_check_rxskip_mode(m);
if (trans->rx_nbits == SPI_NBITS_DUAL && !espi->rxskip) {
@@ -445,6 +493,10 @@ static int fsl_espi_trans(struct spi_message *m, struct spi_transfer *trans)
return -EINVAL;
}
+ /* In RXSKIP mode skip first transfer for reads */
+ if (espi->rxskip)
+ espi->rx_t = list_next_entry(espi->rx_t, transfer_list);
+
fsl_espi_copy_to_buf(m, espi);
fsl_espi_setup_transfer(spi, trans);
@@ -453,9 +505,6 @@ static int fsl_espi_trans(struct spi_message *m, struct spi_transfer *trans)
if (trans->delay_usecs)
udelay(trans->delay_usecs);
- if (!ret)
- fsl_espi_copy_from_buf(m, espi);
-
return ret;
}
@@ -556,13 +605,13 @@ static void fsl_espi_cleanup(struct spi_device *spi)
static void fsl_espi_cpu_irq(struct fsl_espi *espi, u32 events)
{
- if (espi->rx_len)
+ if (!espi->rx_done)
fsl_espi_read_rx_fifo(espi, events);
if (!espi->tx_done)
fsl_espi_fill_tx_fifo(espi, events);
- if (!espi->tx_done || espi->rx_len)
+ if (!espi->tx_done || !espi->rx_done)
return;
/* we're done, but check for errors before returning */