#include <linux/spi/spi.h>
#include <asm/io.h>
-#include <asm/arch/board.h>
-#include <asm/arch/gpio.h>
-#include <asm/arch/cpu.h>
+#include <mach/board.h>
+#include <mach/gpio.h>
+#include <mach/cpu.h>
#include "atmel_spi.h"
* The core SPI transfer engine just talks to a register bank to set up
* DMA transfers; transfer queue progress is driven by IRQs. The clock
* framework provides the base clock, subdivided for each spi_device.
- *
- * Newer controllers, marked with "new_1" flag, have:
- * - CR.LASTXFER
- * - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero)
- * - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs)
- * - SPI_CSRx.CSAAT
- * - SPI_CSRx.SBCR allows faster clocking
*/
struct atmel_spi {
spinlock_t lock;
int irq;
struct clk *clk;
struct platform_device *pdev;
- unsigned new_1:1;
+ struct spi_device *stay;
u8 stopping;
struct list_head queue;
struct spi_transfer *current_transfer;
- unsigned long remaining_bytes;
+ unsigned long current_remaining_bytes;
+ struct spi_transfer *next_transfer;
+ unsigned long next_remaining_bytes;
void *buffer;
dma_addr_t buffer_dma;
};
+/* Controller-specific per-slave state */
+struct atmel_spi_device {
+ unsigned int npcs_pin;
+ u32 csr;
+};
+
#define BUFFER_SIZE PAGE_SIZE
#define INVALID_DMA_ADDRESS 0xffffffff
/*
+ * Version 2 of the SPI controller has
+ * - CR.LASTXFER
+ * - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero)
+ * - 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)
+{
+ return !cpu_is_at91rm9200();
+}
+
+/*
* Earlier SPI controllers (e.g. on at91rm9200) have a design bug whereby
* they assume that spi slave device state will not change on deselect, so
- * that automagic deselection is OK. Not so! Workaround uses nCSx pins
- * as GPIOs; or newer controllers have CSAAT and friends.
+ * that automagic deselection is OK. ("NPCSx rises if no data is to be
+ * transmitted") Not so! Workaround uses nCSx pins as GPIOs; or newer
+ * controllers have CSAAT and friends.
+ *
+ * Since the CSAAT functionality is a bit weird on newer controllers as
+ * well, we use GPIO to control nCSx pins on all controllers, updating
+ * MR.PCS to avoid confusing the controller. Using GPIOs also lets us
+ * support active-high chipselects despite the controller's belief that
+ * only active-low devices/systems exists.
*
- * Since the CSAAT functionality is a bit weird on newer controllers
- * as well, we use GPIO to control nCSx pins on all controllers.
+ * However, at91rm9200 has a second erratum whereby nCS0 doesn't work
+ * right when driven with GPIO. ("Mode Fault does not allow more than one
+ * 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 inline void cs_activate(struct spi_device *spi)
+static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
{
- unsigned gpio = (unsigned) spi->controller_data;
+ struct atmel_spi_device *asd = spi->controller_state;
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.
+ */
+ spi_writel(as, CSR0, asd->csr);
+ spi_writel(as, MR, SPI_BF(PCS, 0x0e) | SPI_BIT(MODFDIS)
+ | SPI_BIT(MSTR));
+ mr = spi_readl(as, MR);
+ gpio_set_value(asd->npcs_pin, active);
+ } else {
+ u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0;
+ int i;
+ u32 csr;
+
+ /* Make sure clock polarity is correct */
+ for (i = 0; i < spi->master->num_chipselect; i++) {
+ csr = spi_readl(as, CSR0 + 4 * i);
+ if ((csr ^ cpol) & SPI_BIT(CPOL))
+ spi_writel(as, CSR0 + 4 * i,
+ csr ^ SPI_BIT(CPOL));
+ }
+
+ mr = spi_readl(as, MR);
+ mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr);
+ if (spi->chip_select != 0)
+ gpio_set_value(asd->npcs_pin, active);
+ spi_writel(as, MR, mr);
+ }
- dev_dbg(&spi->dev, "activate %u%s\n", gpio, active ? " (high)" : "");
- gpio_set_value(gpio, active);
+ dev_dbg(&spi->dev, "activate %u%s, mr %08x\n",
+ asd->npcs_pin, active ? " (high)" : "",
+ mr);
}
-static inline void cs_deactivate(struct spi_device *spi)
+static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
{
- unsigned gpio = (unsigned) spi->controller_data;
+ struct atmel_spi_device *asd = spi->controller_state;
unsigned active = spi->mode & SPI_CS_HIGH;
+ u32 mr;
+
+ /* only deactivate *this* device; sometimes transfers to
+ * another device may be active when this routine is called.
+ */
+ mr = spi_readl(as, MR);
+ if (~SPI_BFEXT(PCS, mr) & (1 << spi->chip_select)) {
+ mr = SPI_BFINS(PCS, 0xf, mr);
+ spi_writel(as, MR, mr);
+ }
+
+ dev_dbg(&spi->dev, "DEactivate %u%s, mr %08x\n",
+ asd->npcs_pin, active ? " (low)" : "",
+ mr);
- dev_dbg(&spi->dev, "DEactivate %u%s\n", gpio, active ? " (low)" : "");
- gpio_set_value(gpio, !active);
+ if (atmel_spi_is_v2() || spi->chip_select != 0)
+ gpio_set_value(asd->npcs_pin, !active);
+}
+
+static inline int atmel_spi_xfer_is_last(struct spi_message *msg,
+ struct spi_transfer *xfer)
+{
+ return msg->transfers.prev == &xfer->transfer_list;
+}
+
+static inline int atmel_spi_xfer_can_be_chained(struct spi_transfer *xfer)
+{
+ return xfer->delay_usecs == 0 && !xfer->cs_change;
+}
+
+static void atmel_spi_next_xfer_data(struct spi_master *master,
+ struct spi_transfer *xfer,
+ dma_addr_t *tx_dma,
+ dma_addr_t *rx_dma,
+ u32 *plen)
+{
+ struct atmel_spi *as = spi_master_get_devdata(master);
+ u32 len = *plen;
+
+ /* use scratch buffer only when rx or tx data is unspecified */
+ if (xfer->rx_buf)
+ *rx_dma = xfer->rx_dma + xfer->len - len;
+ else {
+ *rx_dma = as->buffer_dma;
+ if (len > BUFFER_SIZE)
+ len = BUFFER_SIZE;
+ }
+ if (xfer->tx_buf)
+ *tx_dma = xfer->tx_dma + xfer->len - len;
+ else {
+ *tx_dma = as->buffer_dma;
+ if (len > BUFFER_SIZE)
+ len = BUFFER_SIZE;
+ memset(as->buffer, 0, len);
+ dma_sync_single_for_device(&as->pdev->dev,
+ as->buffer_dma, len, DMA_TO_DEVICE);
+ }
+
+ *plen = len;
}
/*
{
struct atmel_spi *as = spi_master_get_devdata(master);
struct spi_transfer *xfer;
- u32 len;
+ u32 len, remaining;
+ u32 ieval;
dma_addr_t tx_dma, rx_dma;
- xfer = as->current_transfer;
- if (!xfer || as->remaining_bytes == 0) {
- if (xfer)
- xfer = list_entry(xfer->transfer_list.next,
- struct spi_transfer, transfer_list);
- else
- xfer = list_entry(msg->transfers.next,
- struct spi_transfer, transfer_list);
- as->remaining_bytes = xfer->len;
- as->current_transfer = xfer;
- }
+ if (!as->current_transfer)
+ xfer = list_entry(msg->transfers.next,
+ struct spi_transfer, transfer_list);
+ else if (!as->next_transfer)
+ xfer = list_entry(as->current_transfer->transfer_list.next,
+ struct spi_transfer, transfer_list);
+ else
+ xfer = NULL;
- len = as->remaining_bytes;
+ if (xfer) {
+ spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
- tx_dma = xfer->tx_dma + xfer->len - len;
- rx_dma = xfer->rx_dma + xfer->len - len;
+ len = xfer->len;
+ atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len);
+ remaining = xfer->len - len;
- /* use scratch buffer only when rx or tx data is unspecified */
- if (!xfer->rx_buf) {
- rx_dma = as->buffer_dma;
- if (len > BUFFER_SIZE)
- len = BUFFER_SIZE;
- }
- if (!xfer->tx_buf) {
- tx_dma = as->buffer_dma;
- if (len > BUFFER_SIZE)
- len = BUFFER_SIZE;
- memset(as->buffer, 0, len);
- dma_sync_single_for_device(&as->pdev->dev,
- as->buffer_dma, len, DMA_TO_DEVICE);
+ spi_writel(as, RPR, rx_dma);
+ spi_writel(as, TPR, tx_dma);
+
+ if (msg->spi->bits_per_word > 8)
+ len >>= 1;
+ spi_writel(as, RCR, len);
+ spi_writel(as, TCR, len);
+
+ dev_dbg(&msg->spi->dev,
+ " start 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);
+ } else {
+ xfer = as->next_transfer;
+ remaining = as->next_remaining_bytes;
}
- spi_writel(as, RPR, rx_dma);
- spi_writel(as, TPR, tx_dma);
+ as->current_transfer = xfer;
+ as->current_remaining_bytes = remaining;
- as->remaining_bytes -= len;
- if (msg->spi->bits_per_word > 8)
- len >>= 1;
+ if (remaining > 0)
+ len = remaining;
+ else if (!atmel_spi_xfer_is_last(msg, xfer)
+ && atmel_spi_xfer_can_be_chained(xfer)) {
+ xfer = list_entry(xfer->transfer_list.next,
+ struct spi_transfer, transfer_list);
+ len = xfer->len;
+ } else
+ xfer = NULL;
- /* REVISIT: when xfer->delay_usecs == 0, the PDC "next transfer"
- * mechanism might help avoid the IRQ latency between transfers
- *
- * We're also waiting for ENDRX before we start the next
+ as->next_transfer = xfer;
+
+ if (xfer) {
+ u32 total;
+
+ total = len;
+ atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len);
+ as->next_remaining_bytes = total - len;
+
+ spi_writel(as, RNPR, rx_dma);
+ spi_writel(as, TNPR, tx_dma);
+
+ if (msg->spi->bits_per_word > 8)
+ len >>= 1;
+ spi_writel(as, RNCR, len);
+ spi_writel(as, TNCR, len);
+
+ dev_dbg(&msg->spi->dev,
+ " next 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);
+ ieval = SPI_BIT(ENDRX) | SPI_BIT(OVRES);
+ } else {
+ spi_writel(as, RNCR, 0);
+ spi_writel(as, TNCR, 0);
+ ieval = SPI_BIT(RXBUFF) | SPI_BIT(ENDRX) | SPI_BIT(OVRES);
+ }
+
+ /* REVISIT: We're waiting for ENDRX before we start the next
* transfer because we need to handle some difficult timing
* issues otherwise. If we wait for ENDTX in one transfer and
* then starts waiting for ENDRX in the next, it's difficult
*
* It should be doable, though. Just not now...
*/
- spi_writel(as, TNCR, 0);
- spi_writel(as, RNCR, 0);
- spi_writel(as, IER, SPI_BIT(ENDRX) | SPI_BIT(OVRES));
-
- dev_dbg(&msg->spi->dev,
- " start xfer %p: len %u tx %p/%08x rx %p/%08x imr %03x\n",
- xfer, xfer->len, xfer->tx_buf, xfer->tx_dma,
- xfer->rx_buf, xfer->rx_dma, spi_readl(as, IMR));
-
- spi_writel(as, TCR, len);
- spi_writel(as, RCR, len);
+ spi_writel(as, IER, ieval);
spi_writel(as, PTCR, SPI_BIT(TXTEN) | SPI_BIT(RXTEN));
}
{
struct atmel_spi *as = spi_master_get_devdata(master);
struct spi_message *msg;
- u32 mr;
+ struct spi_device *spi;
BUG_ON(as->current_transfer);
msg = list_entry(as->queue.next, struct spi_message, queue);
+ spi = msg->spi;
- /* Select the chip */
- mr = spi_readl(as, MR);
- mr = SPI_BFINS(PCS, ~(1 << msg->spi->chip_select), mr);
- spi_writel(as, MR, mr);
- cs_activate(msg->spi);
+ dev_dbg(master->dev.parent, "start message %p for %s\n",
+ msg, dev_name(&spi->dev));
+
+ /* select chip if it's not still active */
+ if (as->stay) {
+ if (as->stay != spi) {
+ cs_deactivate(as, as->stay);
+ cs_activate(as, spi);
+ }
+ as->stay = NULL;
+ } else
+ cs_activate(as, spi);
atmel_spi_next_xfer(master, msg);
}
-static void
+/*
+ * For DMA, tx_buf/tx_dma have the same relationship as rx_buf/rx_dma:
+ * - The buffer is either valid for CPU access, else NULL
+ * - If the buffer is valid, so is its DMA addresss
+ *
+ * This driver manages the dma addresss unless message->is_dma_mapped.
+ */
+static int
atmel_spi_dma_map_xfer(struct atmel_spi *as, struct spi_transfer *xfer)
{
+ struct device *dev = &as->pdev->dev;
+
xfer->tx_dma = xfer->rx_dma = INVALID_DMA_ADDRESS;
- if (xfer->tx_buf)
- xfer->tx_dma = dma_map_single(&as->pdev->dev,
+ if (xfer->tx_buf) {
+ xfer->tx_dma = dma_map_single(dev,
(void *) xfer->tx_buf, xfer->len,
DMA_TO_DEVICE);
- if (xfer->rx_buf)
- xfer->rx_dma = dma_map_single(&as->pdev->dev,
+ if (dma_mapping_error(dev, xfer->tx_dma))
+ return -ENOMEM;
+ }
+ if (xfer->rx_buf) {
+ xfer->rx_dma = dma_map_single(dev,
xfer->rx_buf, xfer->len,
DMA_FROM_DEVICE);
+ if (dma_mapping_error(dev, xfer->rx_dma)) {
+ if (xfer->tx_buf)
+ dma_unmap_single(dev,
+ xfer->tx_dma, xfer->len,
+ DMA_TO_DEVICE);
+ return -ENOMEM;
+ }
+ }
+ return 0;
}
static void atmel_spi_dma_unmap_xfer(struct spi_master *master,
struct spi_transfer *xfer)
{
if (xfer->tx_dma != INVALID_DMA_ADDRESS)
- dma_unmap_single(master->cdev.dev, xfer->tx_dma,
+ dma_unmap_single(master->dev.parent, xfer->tx_dma,
xfer->len, DMA_TO_DEVICE);
if (xfer->rx_dma != INVALID_DMA_ADDRESS)
- dma_unmap_single(master->cdev.dev, xfer->rx_dma,
+ dma_unmap_single(master->dev.parent, xfer->rx_dma,
xfer->len, DMA_FROM_DEVICE);
}
static void
atmel_spi_msg_done(struct spi_master *master, struct atmel_spi *as,
- struct spi_message *msg, int status)
+ struct spi_message *msg, int status, int stay)
{
- cs_deactivate(msg->spi);
+ if (!stay || status < 0)
+ cs_deactivate(as, msg->spi);
+ else
+ as->stay = msg->spi;
+
list_del(&msg->queue);
msg->status = status;
- dev_dbg(master->cdev.dev,
+ dev_dbg(master->dev.parent,
"xfer complete: %u bytes transferred\n",
msg->actual_length);
spin_lock(&as->lock);
as->current_transfer = NULL;
+ as->next_transfer = NULL;
/* continue if needed */
if (list_empty(&as->queue) || as->stopping)
ret = IRQ_HANDLED;
- spi_writel(as, IDR, (SPI_BIT(ENDTX) | SPI_BIT(ENDRX)
+ spi_writel(as, IDR, (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX)
| SPI_BIT(OVRES)));
/*
if (xfer->delay_usecs)
udelay(xfer->delay_usecs);
- dev_warn(master->cdev.dev, "fifo overrun (%u/%u remaining)\n",
+ dev_warn(master->dev.parent, "overrun (%u/%u remaining)\n",
spi_readl(as, TCR), spi_readl(as, RCR));
/*
if (spi_readl(as, SR) & SPI_BIT(TXEMPTY))
break;
if (!timeout)
- dev_warn(master->cdev.dev,
+ dev_warn(master->dev.parent,
"timeout waiting for TXEMPTY");
while (spi_readl(as, SR) & SPI_BIT(RDRF))
spi_readl(as, RDR);
/* Clear any overrun happening while cleaning up */
spi_readl(as, SR);
- atmel_spi_msg_done(master, as, msg, -EIO);
- } else if (pending & SPI_BIT(ENDRX)) {
+ atmel_spi_msg_done(master, as, msg, -EIO, 0);
+ } else if (pending & (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX))) {
ret = IRQ_HANDLED;
spi_writel(as, IDR, pending);
- if (as->remaining_bytes == 0) {
+ if (as->current_remaining_bytes == 0) {
msg->actual_length += xfer->len;
if (!msg->is_dma_mapped)
if (xfer->delay_usecs)
udelay(xfer->delay_usecs);
- if (msg->transfers.prev == &xfer->transfer_list) {
+ 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, 0,
+ xfer->cs_change);
} else {
if (xfer->cs_change) {
- cs_deactivate(msg->spi);
+ cs_deactivate(as, msg->spi);
udelay(1);
- cs_activate(msg->spi);
+ cs_activate(as, msg->spi);
}
/*
return ret;
}
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
-
static int atmel_spi_setup(struct spi_device *spi)
{
struct atmel_spi *as;
+ struct atmel_spi_device *asd;
u32 scbr, csr;
unsigned int bits = spi->bits_per_word;
- unsigned long bus_hz, sck_hz;
+ unsigned long bus_hz;
unsigned int npcs_pin;
int ret;
return -EINVAL;
}
- if (bits == 0)
- bits = 8;
if (bits < 8 || bits > 16) {
dev_dbg(&spi->dev,
"setup: invalid bits_per_word %u (8 to 16)\n",
return -EINVAL;
}
- if (spi->mode & ~MODEBITS) {
- dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
- spi->mode & ~MODEBITS);
+ /* see notes above re chipselect */
+ if (!atmel_spi_is_v2()
+ && spi->chip_select == 0
+ && (spi->mode & SPI_CS_HIGH)) {
+ dev_dbg(&spi->dev, "setup: can't be active-high\n");
return -EINVAL;
}
- /* speed zero convention is used by some upper layers */
+ /* v1 chips start out at half the peripheral bus speed. */
bus_hz = clk_get_rate(as->clk);
+ if (!atmel_spi_is_v2())
+ bus_hz /= 2;
+
if (spi->max_speed_hz) {
- /* assume div32/fdiv/mbz == 0 */
- if (!as->new_1)
- bus_hz /= 2;
- scbr = ((bus_hz + spi->max_speed_hz - 1)
- / spi->max_speed_hz);
+ /*
+ * Calculate the lowest divider that satisfies the
+ * constraint, assuming div32/fdiv/mbz == 0.
+ */
+ scbr = DIV_ROUND_UP(bus_hz, spi->max_speed_hz);
+
+ /*
+ * If the resulting divider doesn't fit into the
+ * register bitfield, we can't satisfy the constraint.
+ */
if (scbr >= (1 << SPI_SCBR_SIZE)) {
- dev_dbg(&spi->dev, "setup: %d Hz too slow, scbr %u\n",
- spi->max_speed_hz, scbr);
+ dev_dbg(&spi->dev,
+ "setup: %d Hz too slow, scbr %u; min %ld Hz\n",
+ spi->max_speed_hz, scbr, bus_hz/255);
return -EINVAL;
}
} else
+ /* speed zero means "as slow as possible" */
scbr = 0xff;
- sck_hz = bus_hz / scbr;
csr = SPI_BF(SCBR, scbr) | SPI_BF(BITS, bits - 8);
if (spi->mode & SPI_CPOL)
if (!(spi->mode & SPI_CPHA))
csr |= SPI_BIT(NCPHA);
- /* TODO: DLYBS and DLYBCT */
- csr |= SPI_BF(DLYBS, 10);
- csr |= SPI_BF(DLYBCT, 10);
+ /* DLYBS is mostly irrelevant since we manage chipselect using GPIOs.
+ *
+ * DLYBCT would add delays between words, slowing down transfers.
+ * It could potentially be useful to cope with DMA bottlenecks, but
+ * in those cases it's probably best to just use a lower bitrate.
+ */
+ csr |= SPI_BF(DLYBS, 0);
+ csr |= SPI_BF(DLYBCT, 0);
/* chipselect must have been muxed as GPIO (e.g. in board setup) */
npcs_pin = (unsigned int)spi->controller_data;
- if (!spi->controller_state) {
- ret = gpio_request(npcs_pin, "spi_npcs");
- if (ret)
+ asd = spi->controller_state;
+ if (!asd) {
+ asd = kzalloc(sizeof(struct atmel_spi_device), GFP_KERNEL);
+ if (!asd)
+ return -ENOMEM;
+
+ ret = gpio_request(npcs_pin, dev_name(&spi->dev));
+ if (ret) {
+ kfree(asd);
return ret;
- spi->controller_state = (void *)npcs_pin;
+ }
+
+ asd->npcs_pin = npcs_pin;
+ spi->controller_state = asd;
gpio_direction_output(npcs_pin, !(spi->mode & SPI_CS_HIGH));
+ } else {
+ unsigned long flags;
+
+ spin_lock_irqsave(&as->lock, flags);
+ if (as->stay == spi)
+ as->stay = NULL;
+ cs_deactivate(as, spi);
+ spin_unlock_irqrestore(&as->lock, flags);
}
+ asd->csr = csr;
+
dev_dbg(&spi->dev,
"setup: %lu Hz bpw %u mode 0x%x -> csr%d %08x\n",
- sck_hz, bits, spi->mode, spi->chip_select, csr);
+ bus_hz / scbr, bits, spi->mode, spi->chip_select, csr);
- spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
+ if (!atmel_spi_is_v2())
+ 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->cdev.dev;
+ struct device *controller = spi->master->dev.parent;
as = spi_master_get_devdata(spi->master);
dev_dbg(controller, "new message %p submitted for %s\n",
- msg, spi->dev.bus_id);
+ msg, dev_name(&spi->dev));
- if (unlikely(list_empty(&msg->transfers)
- || !spi->max_speed_hz))
+ if (unlikely(list_empty(&msg->transfers)))
return -EINVAL;
if (as->stopping)
return -ESHUTDOWN;
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
- if (!(xfer->tx_buf || xfer->rx_buf)) {
+ if (!(xfer->tx_buf || xfer->rx_buf) && xfer->len) {
dev_dbg(&spi->dev, "missing rx or tx buf\n");
return -EINVAL;
}
dev_dbg(&spi->dev, "no protocol options yet\n");
return -ENOPROTOOPT;
}
- }
- /* scrub dcache "early" */
- if (!msg->is_dma_mapped) {
- list_for_each_entry(xfer, &msg->transfers, transfer_list)
- atmel_spi_dma_map_xfer(as, xfer);
+ /*
+ * 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.
+ */
+ if (!msg->is_dma_mapped) {
+ if (atmel_spi_dma_map_xfer(as, xfer) < 0)
+ return -ENOMEM;
+ }
}
+#ifdef VERBOSE
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
dev_dbg(controller,
" xfer %p: len %u tx %p/%08x rx %p/%08x\n",
xfer->tx_buf, xfer->tx_dma,
xfer->rx_buf, xfer->rx_dma);
}
+#endif
msg->status = -EINPROGRESS;
msg->actual_length = 0;
static void atmel_spi_cleanup(struct spi_device *spi)
{
- if (spi->controller_state)
- gpio_free((unsigned int)spi->controller_data);
+ 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);
+ if (as->stay == spi) {
+ as->stay = NULL;
+ cs_deactivate(as, spi);
+ }
+ spin_unlock_irqrestore(&as->lock, flags);
+
+ spi->controller_state = NULL;
+ gpio_free(gpio);
+ kfree(asd);
}
/*-------------------------------------------------------------------------*/
if (!master)
goto out_free;
+ /* the spi->mode bits understood by this driver: */
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
master->bus_num = pdev->id;
master->num_chipselect = 4;
master->setup = atmel_spi_setup;
as = spi_master_get_devdata(master);
+ /*
+ * Scratch buffer is used for throwaway rx and tx data.
+ * It's coherent to minimize dcache pollution.
+ */
as->buffer = dma_alloc_coherent(&pdev->dev, BUFFER_SIZE,
&as->buffer_dma, GFP_KERNEL);
if (!as->buffer)
goto out_free_buffer;
as->irq = irq;
as->clk = clk;
- if (!cpu_is_at91rm9200())
- as->new_1 = 1;
ret = request_irq(irq, atmel_spi_interrupt, 0,
- pdev->dev.bus_id, master);
+ dev_name(&pdev->dev), master);
if (ret)
goto out_unmap_regs;
/* Initialize the hardware */
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));
spi_writel(as, CR, SPI_BIT(SPIEN));
out_reset_hw:
spi_writel(as, CR, SPI_BIT(SWRST));
+ spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
clk_disable(clk);
free_irq(irq, master);
out_unmap_regs:
spin_lock_irq(&as->lock);
as->stopping = 1;
spi_writel(as, CR, SPI_BIT(SWRST));
+ spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
spi_readl(as, SR);
spin_unlock_irq(&as->lock);
MODULE_DESCRIPTION("Atmel AT32/AT91 SPI Controller driver");
MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>");
MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:atmel_spi");
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff