#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/platform_data/atmel.h>
+#include <linux/platform_data/dma-atmel.h>
#include <linux/of.h>
-#include <asm/io.h>
-#include <asm/gpio.h>
-#include <mach/cpu.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
/* SPI register offsets */
#define SPI_CR 0x0000
#define SPI_CSR1 0x0034
#define SPI_CSR2 0x0038
#define SPI_CSR3 0x003c
+#define SPI_VERSION 0x00fc
#define SPI_RPR 0x0100
#define SPI_RCR 0x0104
#define SPI_TPR 0x0108
#define SPI_FDIV_SIZE 1
#define SPI_MODFDIS_OFFSET 4
#define SPI_MODFDIS_SIZE 1
+#define SPI_WDRBT_OFFSET 5
+#define SPI_WDRBT_SIZE 1
#define SPI_LLB_OFFSET 7
#define SPI_LLB_SIZE 1
#define SPI_PCS_OFFSET 16
#define spi_writel(port,reg,value) \
__raw_writel((value), (port)->regs + SPI_##reg)
+/* use PIO for small transfers, avoiding DMA setup/teardown overhead and
+ * cache operations; better heuristics consider wordsize and bitrate.
+ */
+#define DMA_MIN_BYTES 16
+
+struct atmel_spi_dma {
+ struct dma_chan *chan_rx;
+ struct dma_chan *chan_tx;
+ struct scatterlist sgrx;
+ struct scatterlist sgtx;
+ struct dma_async_tx_descriptor *data_desc_rx;
+ struct dma_async_tx_descriptor *data_desc_tx;
+
+ struct at_dma_slave dma_slave;
+};
+
+struct atmel_spi_caps {
+ bool is_spi2;
+ bool has_wdrbt;
+ bool has_dma_support;
+};
/*
* The core SPI transfer engine just talks to a register bank to set up
*/
struct atmel_spi {
spinlock_t lock;
+ unsigned long flags;
+ phys_addr_t phybase;
void __iomem *regs;
int irq;
struct clk *clk;
u8 stopping;
struct list_head queue;
+ struct tasklet_struct tasklet;
struct spi_transfer *current_transfer;
unsigned long current_remaining_bytes;
struct spi_transfer *next_transfer;
unsigned long next_remaining_bytes;
+ int done_status;
+ /* scratch buffer */
void *buffer;
dma_addr_t buffer_dma;
+
+ struct atmel_spi_caps caps;
+
+ bool use_dma;
+ bool use_pdc;
+ /* dmaengine data */
+ struct atmel_spi_dma dma;
};
/* Controller-specific per-slave state */
* - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs)
* - SPI_CSRx.CSAAT
* - SPI_CSRx.SBCR allows faster clocking
- *
- * We can determine the controller version by reading the VERSION
- * register, but I haven't checked that it exists on all chips, and
- * this is cheaper anyway.
*/
-static bool atmel_spi_is_v2(void)
+static bool atmel_spi_is_v2(struct atmel_spi *as)
{
- return !cpu_is_at91rm9200();
+ return as->caps.is_spi2;
}
/*
* Master on Chip Select 0.") No workaround exists for that ... so for
* nCS0 on that chip, we (a) don't use the GPIO, (b) can't support CS_HIGH,
* and (c) will trigger that first erratum in some cases.
- *
- * TODO: Test if the atmel_spi_is_v2() branch below works on
- * AT91RM9200 if we use some other register than CSR0. However, don't
- * do this unconditionally since AP7000 has an errata where the BITS
- * field in CSR0 overrides all other CSRs.
*/
static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
unsigned active = spi->mode & SPI_CS_HIGH;
u32 mr;
- if (atmel_spi_is_v2()) {
- /*
- * Always use CSR0. This ensures that the clock
- * switches to the correct idle polarity before we
- * toggle the CS.
+ if (atmel_spi_is_v2(as)) {
+ spi_writel(as, CSR0 + 4 * spi->chip_select, asd->csr);
+ /* For the low SPI version, there is a issue that PDC transfer
+ * on CS1,2,3 needs SPI_CSR0.BITS config as SPI_CSR1,2,3.BITS
*/
spi_writel(as, CSR0, asd->csr);
- spi_writel(as, MR, SPI_BF(PCS, 0x0e) | SPI_BIT(MODFDIS)
- | SPI_BIT(MSTR));
+ if (as->caps.has_wdrbt) {
+ spi_writel(as, MR,
+ SPI_BF(PCS, ~(0x01 << spi->chip_select))
+ | SPI_BIT(WDRBT)
+ | SPI_BIT(MODFDIS)
+ | SPI_BIT(MSTR));
+ } else {
+ spi_writel(as, MR,
+ SPI_BF(PCS, ~(0x01 << spi->chip_select))
+ | SPI_BIT(MODFDIS)
+ | SPI_BIT(MSTR));
+ }
+
mr = spi_readl(as, MR);
gpio_set_value(asd->npcs_pin, active);
} else {
asd->npcs_pin, active ? " (low)" : "",
mr);
- if (atmel_spi_is_v2() || spi->chip_select != 0)
+ if (atmel_spi_is_v2(as) || spi->chip_select != 0)
gpio_set_value(asd->npcs_pin, !active);
}
+static void atmel_spi_lock(struct atmel_spi *as)
+{
+ spin_lock_irqsave(&as->lock, as->flags);
+}
+
+static void atmel_spi_unlock(struct atmel_spi *as)
+{
+ spin_unlock_irqrestore(&as->lock, as->flags);
+}
+
+static inline bool atmel_spi_use_dma(struct atmel_spi *as,
+ struct spi_transfer *xfer)
+{
+ return as->use_dma && xfer->len >= DMA_MIN_BYTES;
+}
+
static inline int atmel_spi_xfer_is_last(struct spi_message *msg,
struct spi_transfer *xfer)
{
return xfer->delay_usecs == 0 && !xfer->cs_change;
}
+static int atmel_spi_dma_slave_config(struct atmel_spi *as,
+ struct dma_slave_config *slave_config,
+ u8 bits_per_word)
+{
+ int err = 0;
+
+ if (bits_per_word > 8) {
+ slave_config->dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+ slave_config->src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+ } else {
+ slave_config->dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ slave_config->src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ }
+
+ slave_config->dst_addr = (dma_addr_t)as->phybase + SPI_TDR;
+ slave_config->src_addr = (dma_addr_t)as->phybase + SPI_RDR;
+ slave_config->src_maxburst = 1;
+ slave_config->dst_maxburst = 1;
+ slave_config->device_fc = false;
+
+ slave_config->direction = DMA_MEM_TO_DEV;
+ if (dmaengine_slave_config(as->dma.chan_tx, slave_config)) {
+ dev_err(&as->pdev->dev,
+ "failed to configure tx dma channel\n");
+ err = -EINVAL;
+ }
+
+ slave_config->direction = DMA_DEV_TO_MEM;
+ if (dmaengine_slave_config(as->dma.chan_rx, slave_config)) {
+ dev_err(&as->pdev->dev,
+ "failed to configure rx dma channel\n");
+ err = -EINVAL;
+ }
+
+ return err;
+}
+
+static bool filter(struct dma_chan *chan, void *slave)
+{
+ struct at_dma_slave *sl = slave;
+
+ if (sl->dma_dev == chan->device->dev) {
+ chan->private = sl;
+ return true;
+ } else {
+ return false;
+ }
+}
+
+static int atmel_spi_configure_dma(struct atmel_spi *as)
+{
+ struct at_dma_slave *sdata = &as->dma.dma_slave;
+ struct dma_slave_config slave_config;
+ int err;
+
+ if (sdata && sdata->dma_dev) {
+ dma_cap_mask_t mask;
+
+ /* Try to grab two DMA channels */
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+ as->dma.chan_tx = dma_request_channel(mask, filter, sdata);
+ if (as->dma.chan_tx)
+ as->dma.chan_rx =
+ dma_request_channel(mask, filter, sdata);
+ }
+ if (!as->dma.chan_rx || !as->dma.chan_tx) {
+ dev_err(&as->pdev->dev,
+ "DMA channel not available, SPI unable to use DMA\n");
+ err = -EBUSY;
+ goto error;
+ }
+
+ err = atmel_spi_dma_slave_config(as, &slave_config, 8);
+ if (err)
+ goto error;
+
+ dev_info(&as->pdev->dev,
+ "Using %s (tx) and %s (rx) for DMA transfers\n",
+ dma_chan_name(as->dma.chan_tx),
+ dma_chan_name(as->dma.chan_rx));
+ return 0;
+error:
+ if (as->dma.chan_rx)
+ dma_release_channel(as->dma.chan_rx);
+ if (as->dma.chan_tx)
+ dma_release_channel(as->dma.chan_tx);
+ return err;
+}
+
+static void atmel_spi_stop_dma(struct atmel_spi *as)
+{
+ if (as->dma.chan_rx)
+ as->dma.chan_rx->device->device_control(as->dma.chan_rx,
+ DMA_TERMINATE_ALL, 0);
+ if (as->dma.chan_tx)
+ as->dma.chan_tx->device->device_control(as->dma.chan_tx,
+ DMA_TERMINATE_ALL, 0);
+}
+
+static void atmel_spi_release_dma(struct atmel_spi *as)
+{
+ if (as->dma.chan_rx)
+ dma_release_channel(as->dma.chan_rx);
+ if (as->dma.chan_tx)
+ dma_release_channel(as->dma.chan_tx);
+}
+
+/* This function is called by the DMA driver from tasklet context */
+static void dma_callback(void *data)
+{
+ struct spi_master *master = data;
+ struct atmel_spi *as = spi_master_get_devdata(master);
+
+ /* trigger SPI tasklet */
+ tasklet_schedule(&as->tasklet);
+}
+
+/*
+ * Next transfer using PIO.
+ * lock is held, spi tasklet is blocked
+ */
+static void atmel_spi_next_xfer_pio(struct spi_master *master,
+ struct spi_transfer *xfer)
+{
+ struct atmel_spi *as = spi_master_get_devdata(master);
+
+ dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_pio\n");
+
+ as->current_remaining_bytes = xfer->len;
+
+ /* Make sure data is not remaining in RDR */
+ spi_readl(as, RDR);
+ while (spi_readl(as, SR) & SPI_BIT(RDRF)) {
+ spi_readl(as, RDR);
+ cpu_relax();
+ }
+
+ if (xfer->tx_buf)
+ if (xfer->bits_per_word > 8)
+ spi_writel(as, TDR, *(u16 *)(xfer->tx_buf));
+ else
+ spi_writel(as, TDR, *(u8 *)(xfer->tx_buf));
+ else
+ spi_writel(as, TDR, 0);
+
+ dev_dbg(master->dev.parent,
+ " start pio xfer %p: len %u tx %p rx %p bitpw %d\n",
+ xfer, xfer->len, xfer->tx_buf, xfer->rx_buf,
+ xfer->bits_per_word);
+
+ /* Enable relevant interrupts */
+ spi_writel(as, IER, SPI_BIT(RDRF) | SPI_BIT(OVRES));
+}
+
+/*
+ * Submit next transfer for DMA.
+ * lock is held, spi tasklet is blocked
+ */
+static int atmel_spi_next_xfer_dma_submit(struct spi_master *master,
+ struct spi_transfer *xfer,
+ u32 *plen)
+{
+ struct atmel_spi *as = spi_master_get_devdata(master);
+ struct dma_chan *rxchan = as->dma.chan_rx;
+ struct dma_chan *txchan = as->dma.chan_tx;
+ struct dma_async_tx_descriptor *rxdesc;
+ struct dma_async_tx_descriptor *txdesc;
+ struct dma_slave_config slave_config;
+ dma_cookie_t cookie;
+ u32 len = *plen;
+
+ dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_dma_submit\n");
+
+ /* Check that the channels are available */
+ if (!rxchan || !txchan)
+ return -ENODEV;
+
+ /* release lock for DMA operations */
+ atmel_spi_unlock(as);
+
+ /* prepare the RX dma transfer */
+ sg_init_table(&as->dma.sgrx, 1);
+ if (xfer->rx_buf) {
+ as->dma.sgrx.dma_address = xfer->rx_dma + xfer->len - *plen;
+ } else {
+ as->dma.sgrx.dma_address = as->buffer_dma;
+ if (len > BUFFER_SIZE)
+ len = BUFFER_SIZE;
+ }
+
+ /* prepare the TX dma transfer */
+ sg_init_table(&as->dma.sgtx, 1);
+ if (xfer->tx_buf) {
+ as->dma.sgtx.dma_address = xfer->tx_dma + xfer->len - *plen;
+ } else {
+ as->dma.sgtx.dma_address = as->buffer_dma;
+ if (len > BUFFER_SIZE)
+ len = BUFFER_SIZE;
+ memset(as->buffer, 0, len);
+ }
+
+ sg_dma_len(&as->dma.sgtx) = len;
+ sg_dma_len(&as->dma.sgrx) = len;
+
+ *plen = len;
+
+ if (atmel_spi_dma_slave_config(as, &slave_config, 8))
+ goto err_exit;
+
+ /* Send both scatterlists */
+ rxdesc = rxchan->device->device_prep_slave_sg(rxchan,
+ &as->dma.sgrx,
+ 1,
+ DMA_FROM_DEVICE,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK,
+ NULL);
+ if (!rxdesc)
+ goto err_dma;
+
+ txdesc = txchan->device->device_prep_slave_sg(txchan,
+ &as->dma.sgtx,
+ 1,
+ DMA_TO_DEVICE,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK,
+ NULL);
+ if (!txdesc)
+ goto err_dma;
+
+ dev_dbg(master->dev.parent,
+ " start dma xfer %p: len %u tx %p/%08x rx %p/%08x\n",
+ xfer, xfer->len, xfer->tx_buf, xfer->tx_dma,
+ xfer->rx_buf, xfer->rx_dma);
+
+ /* Enable relevant interrupts */
+ spi_writel(as, IER, SPI_BIT(OVRES));
+
+ /* Put the callback on the RX transfer only, that should finish last */
+ rxdesc->callback = dma_callback;
+ rxdesc->callback_param = master;
+
+ /* Submit and fire RX and TX with TX last so we're ready to read! */
+ cookie = rxdesc->tx_submit(rxdesc);
+ if (dma_submit_error(cookie))
+ goto err_dma;
+ cookie = txdesc->tx_submit(txdesc);
+ if (dma_submit_error(cookie))
+ goto err_dma;
+ rxchan->device->device_issue_pending(rxchan);
+ txchan->device->device_issue_pending(txchan);
+
+ /* take back lock */
+ atmel_spi_lock(as);
+ return 0;
+
+err_dma:
+ spi_writel(as, IDR, SPI_BIT(OVRES));
+ atmel_spi_stop_dma(as);
+err_exit:
+ atmel_spi_lock(as);
+ return -ENOMEM;
+}
+
static void atmel_spi_next_xfer_data(struct spi_master *master,
struct spi_transfer *xfer,
dma_addr_t *tx_dma,
if (len > BUFFER_SIZE)
len = BUFFER_SIZE;
}
+
if (xfer->tx_buf)
*tx_dma = xfer->tx_dma + xfer->len - *plen;
else {
}
/*
- * Submit next transfer for DMA.
+ * Submit next transfer for PDC.
* lock is held, spi irq is blocked
*/
-static void atmel_spi_next_xfer(struct spi_master *master,
+static void atmel_spi_pdc_next_xfer(struct spi_master *master,
struct spi_message *msg)
{
struct atmel_spi *as = spi_master_get_devdata(master);
spi_writel(as, PTCR, SPI_BIT(TXTEN) | SPI_BIT(RXTEN));
}
+/*
+ * Choose way to submit next transfer and start it.
+ * lock is held, spi tasklet is blocked
+ */
+static void atmel_spi_dma_next_xfer(struct spi_master *master,
+ struct spi_message *msg)
+{
+ struct atmel_spi *as = spi_master_get_devdata(master);
+ struct spi_transfer *xfer;
+ u32 remaining, len;
+
+ remaining = as->current_remaining_bytes;
+ if (remaining) {
+ xfer = as->current_transfer;
+ len = remaining;
+ } else {
+ if (!as->current_transfer)
+ xfer = list_entry(msg->transfers.next,
+ struct spi_transfer, transfer_list);
+ else
+ xfer = list_entry(
+ as->current_transfer->transfer_list.next,
+ struct spi_transfer, transfer_list);
+
+ as->current_transfer = xfer;
+ len = xfer->len;
+ }
+
+ if (atmel_spi_use_dma(as, xfer)) {
+ u32 total = len;
+ if (!atmel_spi_next_xfer_dma_submit(master, xfer, &len)) {
+ as->current_remaining_bytes = total - len;
+ return;
+ } else {
+ dev_err(&msg->spi->dev, "unable to use DMA, fallback to PIO\n");
+ }
+ }
+
+ /* use PIO if error appened using DMA */
+ atmel_spi_next_xfer_pio(master, xfer);
+}
+
static void atmel_spi_next_message(struct spi_master *master)
{
struct atmel_spi *as = spi_master_get_devdata(master);
} else
cs_activate(as, spi);
- atmel_spi_next_xfer(master, msg);
+ if (as->use_pdc)
+ atmel_spi_pdc_next_xfer(master, msg);
+ else
+ atmel_spi_dma_next_xfer(master, msg);
}
/*
xfer->len, DMA_FROM_DEVICE);
}
+static void atmel_spi_disable_pdc_transfer(struct atmel_spi *as)
+{
+ spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
+}
+
static void
atmel_spi_msg_done(struct spi_master *master, struct atmel_spi *as,
- struct spi_message *msg, int status, int stay)
+ struct spi_message *msg, int stay)
{
- if (!stay || status < 0)
+ if (!stay || as->done_status < 0)
cs_deactivate(as, msg->spi);
else
as->stay = msg->spi;
list_del(&msg->queue);
- msg->status = status;
+ msg->status = as->done_status;
dev_dbg(master->dev.parent,
"xfer complete: %u bytes transferred\n",
msg->actual_length);
- spin_unlock(&as->lock);
+ atmel_spi_unlock(as);
msg->complete(msg->context);
- spin_lock(&as->lock);
+ atmel_spi_lock(as);
as->current_transfer = NULL;
as->next_transfer = NULL;
+ as->done_status = 0;
/* continue if needed */
- if (list_empty(&as->queue) || as->stopping)
- spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
- else
+ if (list_empty(&as->queue) || as->stopping) {
+ if (as->use_pdc)
+ atmel_spi_disable_pdc_transfer(as);
+ } else {
atmel_spi_next_message(master);
+ }
+}
+
+/* Called from IRQ
+ * lock is held
+ *
+ * Must update "current_remaining_bytes" to keep track of data
+ * to transfer.
+ */
+static void
+atmel_spi_pump_pio_data(struct atmel_spi *as, struct spi_transfer *xfer)
+{
+ u8 *txp;
+ u8 *rxp;
+ u16 *txp16;
+ u16 *rxp16;
+ unsigned long xfer_pos = xfer->len - as->current_remaining_bytes;
+
+ if (xfer->rx_buf) {
+ if (xfer->bits_per_word > 8) {
+ rxp16 = (u16 *)(((u8 *)xfer->rx_buf) + xfer_pos);
+ *rxp16 = spi_readl(as, RDR);
+ } else {
+ rxp = ((u8 *)xfer->rx_buf) + xfer_pos;
+ *rxp = spi_readl(as, RDR);
+ }
+ } else {
+ spi_readl(as, RDR);
+ }
+ if (xfer->bits_per_word > 8) {
+ as->current_remaining_bytes -= 2;
+ if (as->current_remaining_bytes < 0)
+ as->current_remaining_bytes = 0;
+ } else {
+ as->current_remaining_bytes--;
+ }
+
+ if (as->current_remaining_bytes) {
+ if (xfer->tx_buf) {
+ if (xfer->bits_per_word > 8) {
+ txp16 = (u16 *)(((u8 *)xfer->tx_buf)
+ + xfer_pos + 2);
+ spi_writel(as, TDR, *txp16);
+ } else {
+ txp = ((u8 *)xfer->tx_buf) + xfer_pos + 1;
+ spi_writel(as, TDR, *txp);
+ }
+ } else {
+ spi_writel(as, TDR, 0);
+ }
+ }
+}
+
+/* Tasklet
+ * Called from DMA callback + pio transfer and overrun IRQ.
+ */
+static void atmel_spi_tasklet_func(unsigned long data)
+{
+ struct spi_master *master = (struct spi_master *)data;
+ struct atmel_spi *as = spi_master_get_devdata(master);
+ struct spi_message *msg;
+ struct spi_transfer *xfer;
+
+ dev_vdbg(master->dev.parent, "atmel_spi_tasklet_func\n");
+
+ atmel_spi_lock(as);
+
+ xfer = as->current_transfer;
+
+ if (xfer == NULL)
+ /* already been there */
+ goto tasklet_out;
+
+ msg = list_entry(as->queue.next, struct spi_message, queue);
+
+ if (as->current_remaining_bytes == 0) {
+ if (as->done_status < 0) {
+ /* error happened (overrun) */
+ if (atmel_spi_use_dma(as, xfer))
+ atmel_spi_stop_dma(as);
+ } else {
+ /* only update length if no error */
+ msg->actual_length += xfer->len;
+ }
+
+ if (atmel_spi_use_dma(as, xfer))
+ if (!msg->is_dma_mapped)
+ atmel_spi_dma_unmap_xfer(master, xfer);
+
+ if (xfer->delay_usecs)
+ udelay(xfer->delay_usecs);
+
+ if (atmel_spi_xfer_is_last(msg, xfer) || as->done_status < 0) {
+ /* report completed (or erroneous) message */
+ atmel_spi_msg_done(master, as, msg, xfer->cs_change);
+ } else {
+ if (xfer->cs_change) {
+ cs_deactivate(as, msg->spi);
+ udelay(1);
+ cs_activate(as, msg->spi);
+ }
+
+ /*
+ * Not done yet. Submit the next transfer.
+ *
+ * FIXME handle protocol options for xfer
+ */
+ atmel_spi_dma_next_xfer(master, msg);
+ }
+ } else {
+ /*
+ * Keep going, we still have data to send in
+ * the current transfer.
+ */
+ atmel_spi_dma_next_xfer(master, msg);
+ }
+
+tasklet_out:
+ atmel_spi_unlock(as);
}
+/* Interrupt
+ *
+ * No need for locking in this Interrupt handler: done_status is the
+ * only information modified. What we need is the update of this field
+ * before tasklet runs. This is ensured by using barrier.
+ */
static irqreturn_t
-atmel_spi_interrupt(int irq, void *dev_id)
+atmel_spi_pio_interrupt(int irq, void *dev_id)
+{
+ struct spi_master *master = dev_id;
+ struct atmel_spi *as = spi_master_get_devdata(master);
+ u32 status, pending, imr;
+ struct spi_transfer *xfer;
+ int ret = IRQ_NONE;
+
+ imr = spi_readl(as, IMR);
+ status = spi_readl(as, SR);
+ pending = status & imr;
+
+ if (pending & SPI_BIT(OVRES)) {
+ ret = IRQ_HANDLED;
+ spi_writel(as, IDR, SPI_BIT(OVRES));
+ dev_warn(master->dev.parent, "overrun\n");
+
+ /*
+ * When we get an overrun, we disregard the current
+ * transfer. Data will not be copied back from any
+ * bounce buffer and msg->actual_len will not be
+ * updated with the last xfer.
+ *
+ * We will also not process any remaning transfers in
+ * the message.
+ *
+ * All actions are done in tasklet with done_status indication
+ */
+ as->done_status = -EIO;
+ smp_wmb();
+
+ /* Clear any overrun happening while cleaning up */
+ spi_readl(as, SR);
+
+ tasklet_schedule(&as->tasklet);
+
+ } else if (pending & SPI_BIT(RDRF)) {
+ atmel_spi_lock(as);
+
+ if (as->current_remaining_bytes) {
+ ret = IRQ_HANDLED;
+ xfer = as->current_transfer;
+ atmel_spi_pump_pio_data(as, xfer);
+ if (!as->current_remaining_bytes) {
+ /* no more data to xfer, kick tasklet */
+ spi_writel(as, IDR, pending);
+ tasklet_schedule(&as->tasklet);
+ }
+ }
+
+ atmel_spi_unlock(as);
+ } else {
+ WARN_ONCE(pending, "IRQ not handled, pending = %x\n", pending);
+ ret = IRQ_HANDLED;
+ spi_writel(as, IDR, pending);
+ }
+
+ return ret;
+}
+
+static irqreturn_t
+atmel_spi_pdc_interrupt(int irq, void *dev_id)
{
struct spi_master *master = dev_id;
struct atmel_spi *as = spi_master_get_devdata(master);
u32 status, pending, imr;
int ret = IRQ_NONE;
- spin_lock(&as->lock);
+ atmel_spi_lock(as);
xfer = as->current_transfer;
msg = list_entry(as->queue.next, struct spi_message, queue);
/* Clear any overrun happening while cleaning up */
spi_readl(as, SR);
- atmel_spi_msg_done(master, as, msg, -EIO, 0);
+ as->done_status = -EIO;
+ atmel_spi_msg_done(master, as, msg, 0);
} else if (pending & (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX))) {
ret = IRQ_HANDLED;
if (atmel_spi_xfer_is_last(msg, xfer)) {
/* report completed message */
- atmel_spi_msg_done(master, as, msg, 0,
+ atmel_spi_msg_done(master, as, msg,
xfer->cs_change);
} else {
if (xfer->cs_change) {
*
* FIXME handle protocol options for xfer
*/
- atmel_spi_next_xfer(master, msg);
+ atmel_spi_pdc_next_xfer(master, msg);
}
} else {
/*
* Keep going, we still have data to send in
* the current transfer.
*/
- atmel_spi_next_xfer(master, msg);
+ atmel_spi_pdc_next_xfer(master, msg);
}
}
- spin_unlock(&as->lock);
+ atmel_spi_unlock(as);
return ret;
}
}
/* see notes above re chipselect */
- if (!atmel_spi_is_v2()
+ if (!atmel_spi_is_v2(as)
&& spi->chip_select == 0
&& (spi->mode & SPI_CS_HIGH)) {
dev_dbg(&spi->dev, "setup: can't be active-high\n");
/* v1 chips start out at half the peripheral bus speed. */
bus_hz = clk_get_rate(as->clk);
- if (!atmel_spi_is_v2())
+ if (!atmel_spi_is_v2(as))
bus_hz /= 2;
if (spi->max_speed_hz) {
spi->controller_state = asd;
gpio_direction_output(npcs_pin, !(spi->mode & SPI_CS_HIGH));
} else {
- unsigned long flags;
-
- spin_lock_irqsave(&as->lock, flags);
+ atmel_spi_lock(as);
if (as->stay == spi)
as->stay = NULL;
cs_deactivate(as, spi);
- spin_unlock_irqrestore(&as->lock, flags);
+ atmel_spi_unlock(as);
}
asd->csr = csr;
"setup: %lu Hz bpw %u mode 0x%x -> csr%d %08x\n",
bus_hz / scbr, bits, spi->mode, spi->chip_select, csr);
- if (!atmel_spi_is_v2())
+ if (!atmel_spi_is_v2(as))
spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
return 0;
{
struct atmel_spi *as;
struct spi_transfer *xfer;
- unsigned long flags;
struct device *controller = spi->master->dev.parent;
u8 bits;
struct atmel_spi_device *asd;
}
}
+ if (xfer->bits_per_word > 8) {
+ if (xfer->len % 2) {
+ dev_dbg(&spi->dev, "buffer len should be 16 bits aligned\n");
+ return -EINVAL;
+ }
+ }
+
/* FIXME implement these protocol options!! */
- if (xfer->speed_hz) {
- dev_dbg(&spi->dev, "no protocol options yet\n");
+ if (xfer->speed_hz < spi->max_speed_hz) {
+ dev_dbg(&spi->dev, "can't change speed in transfer\n");
return -ENOPROTOOPT;
}
/*
* DMA map early, for performance (empties dcache ASAP) and
- * better fault reporting. This is a DMA-only driver.
- *
- * NOTE that if dma_unmap_single() ever starts to do work on
- * platforms supported by this driver, we would need to clean
- * up mappings for previously-mapped transfers.
+ * better fault reporting.
*/
- if (!msg->is_dma_mapped) {
+ if ((!msg->is_dma_mapped) && (atmel_spi_use_dma(as, xfer)
+ || as->use_pdc)) {
if (atmel_spi_dma_map_xfer(as, xfer) < 0)
return -ENOMEM;
}
msg->status = -EINPROGRESS;
msg->actual_length = 0;
- spin_lock_irqsave(&as->lock, flags);
+ atmel_spi_lock(as);
list_add_tail(&msg->queue, &as->queue);
if (!as->current_transfer)
atmel_spi_next_message(spi->master);
- spin_unlock_irqrestore(&as->lock, flags);
+ atmel_spi_unlock(as);
return 0;
}
struct atmel_spi *as = spi_master_get_devdata(spi->master);
struct atmel_spi_device *asd = spi->controller_state;
unsigned gpio = (unsigned) spi->controller_data;
- unsigned long flags;
if (!asd)
return;
- spin_lock_irqsave(&as->lock, flags);
+ atmel_spi_lock(as);
if (as->stay == spi) {
as->stay = NULL;
cs_deactivate(as, spi);
}
- spin_unlock_irqrestore(&as->lock, flags);
+ atmel_spi_unlock(as);
spi->controller_state = NULL;
gpio_free(gpio);
kfree(asd);
}
+static inline unsigned int atmel_get_version(struct atmel_spi *as)
+{
+ return spi_readl(as, VERSION) & 0x00000fff;
+}
+
+static void atmel_get_caps(struct atmel_spi *as)
+{
+ unsigned int version;
+
+ version = atmel_get_version(as);
+ dev_info(&as->pdev->dev, "version: 0x%x\n", version);
+
+ as->caps.is_spi2 = version > 0x121;
+ as->caps.has_wdrbt = version >= 0x210;
+ as->caps.has_dma_support = version >= 0x212;
+}
+
/*-------------------------------------------------------------------------*/
static int atmel_spi_probe(struct platform_device *pdev)
spin_lock_init(&as->lock);
INIT_LIST_HEAD(&as->queue);
+
as->pdev = pdev;
as->regs = ioremap(regs->start, resource_size(regs));
if (!as->regs)
goto out_free_buffer;
+ as->phybase = regs->start;
as->irq = irq;
as->clk = clk;
- ret = request_irq(irq, atmel_spi_interrupt, 0,
- dev_name(&pdev->dev), master);
+ atmel_get_caps(as);
+
+ as->use_dma = false;
+ as->use_pdc = false;
+ if (as->caps.has_dma_support) {
+ if (atmel_spi_configure_dma(as) == 0)
+ as->use_dma = true;
+ } else {
+ as->use_pdc = true;
+ }
+
+ if (as->caps.has_dma_support && !as->use_dma)
+ dev_info(&pdev->dev, "Atmel SPI Controller using PIO only\n");
+
+ if (as->use_pdc) {
+ ret = request_irq(irq, atmel_spi_pdc_interrupt, 0,
+ dev_name(&pdev->dev), master);
+ } else {
+ tasklet_init(&as->tasklet, atmel_spi_tasklet_func,
+ (unsigned long)master);
+
+ ret = request_irq(irq, atmel_spi_pio_interrupt, 0,
+ dev_name(&pdev->dev), master);
+ }
if (ret)
goto out_unmap_regs;
clk_enable(clk);
spi_writel(as, CR, SPI_BIT(SWRST));
spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
- spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
- spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
+ if (as->caps.has_wdrbt) {
+ spi_writel(as, MR, SPI_BIT(WDRBT) | SPI_BIT(MODFDIS)
+ | SPI_BIT(MSTR));
+ } else {
+ spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
+ }
+
+ if (as->use_pdc)
+ spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
spi_writel(as, CR, SPI_BIT(SPIEN));
/* go! */
ret = spi_register_master(master);
if (ret)
- goto out_reset_hw;
+ goto out_free_dma;
return 0;
-out_reset_hw:
+out_free_dma:
+ if (as->use_dma)
+ atmel_spi_release_dma(as);
+
spi_writel(as, CR, SPI_BIT(SWRST));
spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
clk_disable(clk);
out_unmap_regs:
iounmap(as->regs);
out_free_buffer:
+ if (!as->use_pdc)
+ tasklet_kill(&as->tasklet);
dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer,
as->buffer_dma);
out_free:
struct spi_master *master = platform_get_drvdata(pdev);
struct atmel_spi *as = spi_master_get_devdata(master);
struct spi_message *msg;
+ struct spi_transfer *xfer;
/* reset the hardware and block queue progress */
spin_lock_irq(&as->lock);
as->stopping = 1;
+ if (as->use_dma) {
+ atmel_spi_stop_dma(as);
+ atmel_spi_release_dma(as);
+ }
+
spi_writel(as, CR, SPI_BIT(SWRST));
spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
spi_readl(as, SR);
/* Terminate remaining queued transfers */
list_for_each_entry(msg, &as->queue, queue) {
- /* REVISIT unmapping the dma is a NOP on ARM and AVR32
- * but we shouldn't depend on that...
- */
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ if (!msg->is_dma_mapped
+ && (atmel_spi_use_dma(as, xfer)
+ || as->use_pdc))
+ atmel_spi_dma_unmap_xfer(master, xfer);
+ }
msg->status = -ESHUTDOWN;
msg->complete(msg->context);
}
+ if (!as->use_pdc)
+ tasklet_kill(&as->tasklet);
dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer,
as->buffer_dma);
projects / mirror_ubuntu-bionic-kernel.git / commitdiff