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path: root/drivers/spi/dw_spi.c
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Diffstat (limited to 'drivers/spi/dw_spi.c')
-rw-r--r--drivers/spi/dw_spi.c111
1 files changed, 78 insertions, 33 deletions
diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c
index 31620fae77b..8ed38f1d6c1 100644
--- a/drivers/spi/dw_spi.c
+++ b/drivers/spi/dw_spi.c
@@ -152,6 +152,7 @@ static void mrst_spi_debugfs_remove(struct dw_spi *dws)
#else
static inline int mrst_spi_debugfs_init(struct dw_spi *dws)
{
+ return 0;
}
static inline void mrst_spi_debugfs_remove(struct dw_spi *dws)
@@ -161,14 +162,14 @@ static inline void mrst_spi_debugfs_remove(struct dw_spi *dws)
static void wait_till_not_busy(struct dw_spi *dws)
{
- unsigned long end = jiffies + usecs_to_jiffies(1000);
+ unsigned long end = jiffies + 1 + usecs_to_jiffies(1000);
while (time_before(jiffies, end)) {
if (!(dw_readw(dws, sr) & SR_BUSY))
return;
}
dev_err(&dws->master->dev,
- "DW SPI: Stutus keeps busy for 1000us after a read/write!\n");
+ "DW SPI: Status keeps busy for 1000us after a read/write!\n");
}
static void flush(struct dw_spi *dws)
@@ -358,6 +359,8 @@ static void transfer_complete(struct dw_spi *dws)
static irqreturn_t interrupt_transfer(struct dw_spi *dws)
{
u16 irq_status, irq_mask = 0x3f;
+ u32 int_level = dws->fifo_len / 2;
+ u32 left;
irq_status = dw_readw(dws, isr) & irq_mask;
/* Error handling */
@@ -369,22 +372,23 @@ static irqreturn_t interrupt_transfer(struct dw_spi *dws)
return IRQ_HANDLED;
}
- /* INT comes from tx */
- if (dws->tx && (irq_status & SPI_INT_TXEI)) {
- while (dws->tx < dws->tx_end)
+ if (irq_status & SPI_INT_TXEI) {
+ spi_mask_intr(dws, SPI_INT_TXEI);
+
+ left = (dws->tx_end - dws->tx) / dws->n_bytes;
+ left = (left > int_level) ? int_level : left;
+
+ while (left--)
dws->write(dws);
+ dws->read(dws);
- if (dws->tx == dws->tx_end) {
- spi_mask_intr(dws, SPI_INT_TXEI);
+ /* Re-enable the IRQ if there is still data left to tx */
+ if (dws->tx_end > dws->tx)
+ spi_umask_intr(dws, SPI_INT_TXEI);
+ else
transfer_complete(dws);
- }
}
- /* INT comes from rx */
- if (dws->rx && (irq_status & SPI_INT_RXFI)) {
- if (dws->read(dws))
- transfer_complete(dws);
- }
return IRQ_HANDLED;
}
@@ -404,12 +408,9 @@ static irqreturn_t dw_spi_irq(int irq, void *dev_id)
/* Must be called inside pump_transfers() */
static void poll_transfer(struct dw_spi *dws)
{
- if (dws->tx) {
- while (dws->write(dws))
- dws->read(dws);
- }
+ while (dws->write(dws))
+ dws->read(dws);
- dws->read(dws);
transfer_complete(dws);
}
@@ -428,6 +429,7 @@ static void pump_transfers(unsigned long data)
u8 bits = 0;
u8 imask = 0;
u8 cs_change = 0;
+ u16 txint_level = 0;
u16 clk_div = 0;
u32 speed = 0;
u32 cr0 = 0;
@@ -438,6 +440,9 @@ static void pump_transfers(unsigned long data)
chip = dws->cur_chip;
spi = message->spi;
+ if (unlikely(!chip->clk_div))
+ chip->clk_div = dws->max_freq / chip->speed_hz;
+
if (message->state == ERROR_STATE) {
message->status = -EIO;
goto early_exit;
@@ -492,7 +497,7 @@ static void pump_transfers(unsigned long data)
/* clk_div doesn't support odd number */
clk_div = dws->max_freq / speed;
- clk_div = (clk_div >> 1) << 1;
+ clk_div = (clk_div + 1) & 0xfffe;
chip->speed_hz = speed;
chip->clk_div = clk_div;
@@ -532,14 +537,35 @@ static void pump_transfers(unsigned long data)
}
message->state = RUNNING_STATE;
+ /*
+ * Adjust transfer mode if necessary. Requires platform dependent
+ * chipselect mechanism.
+ */
+ if (dws->cs_control) {
+ if (dws->rx && dws->tx)
+ chip->tmode = 0x00;
+ else if (dws->rx)
+ chip->tmode = 0x02;
+ else
+ chip->tmode = 0x01;
+
+ cr0 &= ~(0x3 << SPI_MODE_OFFSET);
+ cr0 |= (chip->tmode << SPI_TMOD_OFFSET);
+ }
+
/* Check if current transfer is a DMA transaction */
dws->dma_mapped = map_dma_buffers(dws);
+ /*
+ * Interrupt mode
+ * we only need set the TXEI IRQ, as TX/RX always happen syncronizely
+ */
if (!dws->dma_mapped && !chip->poll_mode) {
- if (dws->rx)
- imask |= SPI_INT_RXFI;
- if (dws->tx)
- imask |= SPI_INT_TXEI;
+ int templen = dws->len / dws->n_bytes;
+ txint_level = dws->fifo_len / 2;
+ txint_level = (templen > txint_level) ? txint_level : templen;
+
+ imask |= SPI_INT_TXEI;
dws->transfer_handler = interrupt_transfer;
}
@@ -549,21 +575,23 @@ static void pump_transfers(unsigned long data)
* 2. clk_div is changed
* 3. control value changes
*/
- if (dw_readw(dws, ctrl0) != cr0 || cs_change || clk_div) {
+ if (dw_readw(dws, ctrl0) != cr0 || cs_change || clk_div || imask) {
spi_enable_chip(dws, 0);
if (dw_readw(dws, ctrl0) != cr0)
dw_writew(dws, ctrl0, cr0);
+ spi_set_clk(dws, clk_div ? clk_div : chip->clk_div);
+ spi_chip_sel(dws, spi->chip_select);
+
/* Set the interrupt mask, for poll mode just diable all int */
spi_mask_intr(dws, 0xff);
- if (!chip->poll_mode)
+ if (imask)
spi_umask_intr(dws, imask);
+ if (txint_level)
+ dw_writew(dws, txfltr, txint_level);
- spi_set_clk(dws, clk_div ? clk_div : chip->clk_div);
- spi_chip_sel(dws, spi->chip_select);
spi_enable_chip(dws, 1);
-
if (cs_change)
dws->prev_chip = chip;
}
@@ -712,11 +740,11 @@ static int dw_spi_setup(struct spi_device *spi)
}
chip->bits_per_word = spi->bits_per_word;
+ if (!spi->max_speed_hz) {
+ dev_err(&spi->dev, "No max speed HZ parameter\n");
+ return -EINVAL;
+ }
chip->speed_hz = spi->max_speed_hz;
- if (chip->speed_hz)
- chip->clk_div = 25000000 / chip->speed_hz;
- else
- chip->clk_div = 8; /* default value */
chip->tmode = 0; /* Tx & Rx */
/* Default SPI mode is SCPOL = 0, SCPH = 0 */
@@ -735,7 +763,7 @@ static void dw_spi_cleanup(struct spi_device *spi)
kfree(chip);
}
-static int __init init_queue(struct dw_spi *dws)
+static int __devinit init_queue(struct dw_spi *dws)
{
INIT_LIST_HEAD(&dws->queue);
spin_lock_init(&dws->lock);
@@ -817,6 +845,22 @@ static void spi_hw_init(struct dw_spi *dws)
spi_mask_intr(dws, 0xff);
spi_enable_chip(dws, 1);
flush(dws);
+
+ /*
+ * Try to detect the FIFO depth if not set by interface driver,
+ * the depth could be from 2 to 256 from HW spec
+ */
+ if (!dws->fifo_len) {
+ u32 fifo;
+ for (fifo = 2; fifo <= 257; fifo++) {
+ dw_writew(dws, txfltr, fifo);
+ if (fifo != dw_readw(dws, txfltr))
+ break;
+ }
+
+ dws->fifo_len = (fifo == 257) ? 0 : fifo;
+ dw_writew(dws, txfltr, 0);
+ }
}
int __devinit dw_spi_add_host(struct dw_spi *dws)
@@ -913,6 +957,7 @@ void __devexit dw_spi_remove_host(struct dw_spi *dws)
/* Disconnect from the SPI framework */
spi_unregister_master(dws->master);
}
+EXPORT_SYMBOL(dw_spi_remove_host);
int dw_spi_suspend_host(struct dw_spi *dws)
{
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-30 03:19:53 +0000