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path: root/drivers/spi/spi.c
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Diffstat (limited to 'drivers/spi/spi.c')
-rw-r--r--drivers/spi/spi.c383
1 files changed, 321 insertions, 62 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 349ebba4b19..d4f9670b51b 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -24,6 +24,8 @@
#include <linux/device.h>
#include <linux/init.h>
#include <linux/cache.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
#include <linux/mutex.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
@@ -58,6 +60,11 @@ static ssize_t
modalias_show(struct device *dev, struct device_attribute *a, char *buf)
{
const struct spi_device *spi = to_spi_device(dev);
+ int len;
+
+ len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
+ if (len != -ENODEV)
+ return len;
return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
}
@@ -114,6 +121,11 @@ static int spi_match_device(struct device *dev, struct device_driver *drv)
static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
{
const struct spi_device *spi = to_spi_device(dev);
+ int rc;
+
+ rc = acpi_device_uevent_modalias(dev, env);
+ if (rc != -ENODEV)
+ return rc;
add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
return 0;
@@ -245,13 +257,12 @@ EXPORT_SYMBOL_GPL(spi_bus_type);
static int spi_drv_probe(struct device *dev)
{
const struct spi_driver *sdrv = to_spi_driver(dev->driver);
- struct spi_device *spi = to_spi_device(dev);
int ret;
- acpi_dev_pm_attach(&spi->dev, true);
- ret = sdrv->probe(spi);
+ acpi_dev_pm_attach(dev, true);
+ ret = sdrv->probe(to_spi_device(dev));
if (ret)
- acpi_dev_pm_detach(&spi->dev, true);
+ acpi_dev_pm_detach(dev, true);
return ret;
}
@@ -259,11 +270,10 @@ static int spi_drv_probe(struct device *dev)
static int spi_drv_remove(struct device *dev)
{
const struct spi_driver *sdrv = to_spi_driver(dev->driver);
- struct spi_device *spi = to_spi_device(dev);
int ret;
- ret = sdrv->remove(spi);
- acpi_dev_pm_detach(&spi->dev, true);
+ ret = sdrv->remove(to_spi_device(dev));
+ acpi_dev_pm_detach(dev, true);
return ret;
}
@@ -370,6 +380,17 @@ static void spi_dev_set_name(struct spi_device *spi)
spi->chip_select);
}
+static int spi_dev_check(struct device *dev, void *data)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ struct spi_device *new_spi = data;
+
+ if (spi->master == new_spi->master &&
+ spi->chip_select == new_spi->chip_select)
+ return -EBUSY;
+ return 0;
+}
+
/**
* spi_add_device - Add spi_device allocated with spi_alloc_device
* @spi: spi_device to register
@@ -384,7 +405,6 @@ int spi_add_device(struct spi_device *spi)
static DEFINE_MUTEX(spi_add_lock);
struct spi_master *master = spi->master;
struct device *dev = master->dev.parent;
- struct device *d;
int status;
/* Chipselects are numbered 0..max; validate. */
@@ -404,12 +424,10 @@ int spi_add_device(struct spi_device *spi)
*/
mutex_lock(&spi_add_lock);
- d = bus_find_device_by_name(&spi_bus_type, NULL, dev_name(&spi->dev));
- if (d != NULL) {
+ status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
+ if (status) {
dev_err(dev, "chipselect %d already in use\n",
spi->chip_select);
- put_device(d);
- status = -EBUSY;
goto done;
}
@@ -562,6 +580,190 @@ static void spi_set_cs(struct spi_device *spi, bool enable)
spi->master->set_cs(spi, !enable);
}
+#ifdef CONFIG_HAS_DMA
+static int spi_map_buf(struct spi_master *master, struct device *dev,
+ struct sg_table *sgt, void *buf, size_t len,
+ enum dma_data_direction dir)
+{
+ const bool vmalloced_buf = is_vmalloc_addr(buf);
+ const int desc_len = vmalloced_buf ? PAGE_SIZE : master->max_dma_len;
+ const int sgs = DIV_ROUND_UP(len, desc_len);
+ struct page *vm_page;
+ void *sg_buf;
+ size_t min;
+ int i, ret;
+
+ ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
+ if (ret != 0)
+ return ret;
+
+ for (i = 0; i < sgs; i++) {
+ min = min_t(size_t, len, desc_len);
+
+ if (vmalloced_buf) {
+ vm_page = vmalloc_to_page(buf);
+ if (!vm_page) {
+ sg_free_table(sgt);
+ return -ENOMEM;
+ }
+ sg_buf = page_address(vm_page) +
+ ((size_t)buf & ~PAGE_MASK);
+ } else {
+ sg_buf = buf;
+ }
+
+ sg_set_buf(&sgt->sgl[i], sg_buf, min);
+
+ buf += min;
+ len -= min;
+ }
+
+ ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
+ if (ret < 0) {
+ sg_free_table(sgt);
+ return ret;
+ }
+
+ sgt->nents = ret;
+
+ return 0;
+}
+
+static void spi_unmap_buf(struct spi_master *master, struct device *dev,
+ struct sg_table *sgt, enum dma_data_direction dir)
+{
+ if (sgt->orig_nents) {
+ dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
+ sg_free_table(sgt);
+ }
+}
+
+static int __spi_map_msg(struct spi_master *master, struct spi_message *msg)
+{
+ struct device *tx_dev, *rx_dev;
+ struct spi_transfer *xfer;
+ int ret;
+
+ if (!master->can_dma)
+ return 0;
+
+ tx_dev = &master->dma_tx->dev->device;
+ rx_dev = &master->dma_rx->dev->device;
+
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ if (!master->can_dma(master, msg->spi, xfer))
+ continue;
+
+ if (xfer->tx_buf != NULL) {
+ ret = spi_map_buf(master, tx_dev, &xfer->tx_sg,
+ (void *)xfer->tx_buf, xfer->len,
+ DMA_TO_DEVICE);
+ if (ret != 0)
+ return ret;
+ }
+
+ if (xfer->rx_buf != NULL) {
+ ret = spi_map_buf(master, rx_dev, &xfer->rx_sg,
+ xfer->rx_buf, xfer->len,
+ DMA_FROM_DEVICE);
+ if (ret != 0) {
+ spi_unmap_buf(master, tx_dev, &xfer->tx_sg,
+ DMA_TO_DEVICE);
+ return ret;
+ }
+ }
+ }
+
+ master->cur_msg_mapped = true;
+
+ return 0;
+}
+
+static int spi_unmap_msg(struct spi_master *master, struct spi_message *msg)
+{
+ struct spi_transfer *xfer;
+ struct device *tx_dev, *rx_dev;
+
+ if (!master->cur_msg_mapped || !master->can_dma)
+ return 0;
+
+ tx_dev = &master->dma_tx->dev->device;
+ rx_dev = &master->dma_rx->dev->device;
+
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ if (!master->can_dma(master, msg->spi, xfer))
+ continue;
+
+ spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
+ spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
+ }
+
+ return 0;
+}
+#else /* !CONFIG_HAS_DMA */
+static inline int __spi_map_msg(struct spi_master *master,
+ struct spi_message *msg)
+{
+ return 0;
+}
+
+static inline int spi_unmap_msg(struct spi_master *master,
+ struct spi_message *msg)
+{
+ return 0;
+}
+#endif /* !CONFIG_HAS_DMA */
+
+static int spi_map_msg(struct spi_master *master, struct spi_message *msg)
+{
+ struct spi_transfer *xfer;
+ void *tmp;
+ unsigned int max_tx, max_rx;
+
+ if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) {
+ max_tx = 0;
+ max_rx = 0;
+
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ if ((master->flags & SPI_MASTER_MUST_TX) &&
+ !xfer->tx_buf)
+ max_tx = max(xfer->len, max_tx);
+ if ((master->flags & SPI_MASTER_MUST_RX) &&
+ !xfer->rx_buf)
+ max_rx = max(xfer->len, max_rx);
+ }
+
+ if (max_tx) {
+ tmp = krealloc(master->dummy_tx, max_tx,
+ GFP_KERNEL | GFP_DMA);
+ if (!tmp)
+ return -ENOMEM;
+ master->dummy_tx = tmp;
+ memset(tmp, 0, max_tx);
+ }
+
+ if (max_rx) {
+ tmp = krealloc(master->dummy_rx, max_rx,
+ GFP_KERNEL | GFP_DMA);
+ if (!tmp)
+ return -ENOMEM;
+ master->dummy_rx = tmp;
+ }
+
+ if (max_tx || max_rx) {
+ list_for_each_entry(xfer, &msg->transfers,
+ transfer_list) {
+ if (!xfer->tx_buf)
+ xfer->tx_buf = master->dummy_tx;
+ if (!xfer->rx_buf)
+ xfer->rx_buf = master->dummy_rx;
+ }
+ }
+ }
+
+ return __spi_map_msg(master, msg);
+}
+
/*
* spi_transfer_one_message - Default implementation of transfer_one_message()
*
@@ -573,9 +775,9 @@ static int spi_transfer_one_message(struct spi_master *master,
struct spi_message *msg)
{
struct spi_transfer *xfer;
- bool cur_cs = true;
bool keep_cs = false;
int ret = 0;
+ int ms = 1;
spi_set_cs(msg->spi, true);
@@ -591,8 +793,19 @@ static int spi_transfer_one_message(struct spi_master *master,
goto out;
}
- if (ret > 0)
- wait_for_completion(&master->xfer_completion);
+ if (ret > 0) {
+ ret = 0;
+ ms = xfer->len * 8 * 1000 / xfer->speed_hz;
+ ms += ms + 100; /* some tolerance */
+
+ ms = wait_for_completion_timeout(&master->xfer_completion,
+ msecs_to_jiffies(ms));
+ }
+
+ if (ms == 0) {
+ dev_err(&msg->spi->dev, "SPI transfer timed out\n");
+ msg->status = -ETIMEDOUT;
+ }
trace_spi_transfer_stop(msg, xfer);
@@ -607,8 +820,9 @@ static int spi_transfer_one_message(struct spi_master *master,
&msg->transfers)) {
keep_cs = true;
} else {
- cur_cs = !cur_cs;
- spi_set_cs(msg->spi, cur_cs);
+ spi_set_cs(msg->spi, false);
+ udelay(10);
+ spi_set_cs(msg->spi, true);
}
}
@@ -632,7 +846,7 @@ out:
*
* Called by SPI drivers using the core transfer_one_message()
* implementation to notify it that the current interrupt driven
- * transfer has finised and the next one may be scheduled.
+ * transfer has finished and the next one may be scheduled.
*/
void spi_finalize_current_transfer(struct spi_master *master)
{
@@ -666,6 +880,10 @@ static void spi_pump_messages(struct kthread_work *work)
}
master->busy = false;
spin_unlock_irqrestore(&master->queue_lock, flags);
+ kfree(master->dummy_rx);
+ master->dummy_rx = NULL;
+ kfree(master->dummy_tx);
+ master->dummy_tx = NULL;
if (master->unprepare_transfer_hardware &&
master->unprepare_transfer_hardware(master))
dev_err(&master->dev,
@@ -685,7 +903,7 @@ static void spi_pump_messages(struct kthread_work *work)
}
/* Extract head of queue */
master->cur_msg =
- list_entry(master->queue.next, struct spi_message, queue);
+ list_first_entry(&master->queue, struct spi_message, queue);
list_del_init(&master->cur_msg->queue);
if (master->busy)
@@ -732,6 +950,13 @@ static void spi_pump_messages(struct kthread_work *work)
master->cur_msg_prepared = true;
}
+ ret = spi_map_msg(master, master->cur_msg);
+ if (ret) {
+ master->cur_msg->status = ret;
+ spi_finalize_current_message(master);
+ return;
+ }
+
ret = master->transfer_one_message(master, master->cur_msg);
if (ret) {
dev_err(&master->dev,
@@ -791,11 +1016,8 @@ struct spi_message *spi_get_next_queued_message(struct spi_master *master)
/* get a pointer to the next message, if any */
spin_lock_irqsave(&master->queue_lock, flags);
- if (list_empty(&master->queue))
- next = NULL;
- else
- next = list_entry(master->queue.next,
- struct spi_message, queue);
+ next = list_first_entry_or_null(&master->queue, struct spi_message,
+ queue);
spin_unlock_irqrestore(&master->queue_lock, flags);
return next;
@@ -822,6 +1044,8 @@ void spi_finalize_current_message(struct spi_master *master)
queue_kthread_work(&master->kworker, &master->pump_messages);
spin_unlock_irqrestore(&master->queue_lock, flags);
+ spi_unmap_msg(master, mesg);
+
if (master->cur_msg_prepared && master->unprepare_message) {
ret = master->unprepare_message(master, mesg);
if (ret) {
@@ -875,7 +1099,7 @@ static int spi_stop_queue(struct spi_master *master)
*/
while ((!list_empty(&master->queue) || master->busy) && limit--) {
spin_unlock_irqrestore(&master->queue_lock, flags);
- msleep(10);
+ usleep_range(10000, 11000);
spin_lock_irqsave(&master->queue_lock, flags);
}
@@ -948,7 +1172,6 @@ static int spi_master_initialize_queue(struct spi_master *master)
{
int ret;
- master->queued = true;
master->transfer = spi_queued_transfer;
if (!master->transfer_one_message)
master->transfer_one_message = spi_transfer_one_message;
@@ -959,6 +1182,7 @@ static int spi_master_initialize_queue(struct spi_master *master)
dev_err(&master->dev, "problem initializing queue\n");
goto err_init_queue;
}
+ master->queued = true;
ret = spi_start_queue(master);
if (ret) {
dev_err(&master->dev, "problem starting queue\n");
@@ -968,8 +1192,8 @@ static int spi_master_initialize_queue(struct spi_master *master)
return 0;
err_start_queue:
-err_init_queue:
spi_destroy_queue(master);
+err_init_queue:
return ret;
}
@@ -1031,6 +1255,8 @@ static void of_register_spi_devices(struct spi_master *master)
spi->mode |= SPI_CS_HIGH;
if (of_find_property(nc, "spi-3wire", NULL))
spi->mode |= SPI_3WIRE;
+ if (of_find_property(nc, "spi-lsb-first", NULL))
+ spi->mode |= SPI_LSB_FIRST;
/* Device DUAL/QUAD mode */
if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
@@ -1044,11 +1270,10 @@ static void of_register_spi_devices(struct spi_master *master)
spi->mode |= SPI_TX_QUAD;
break;
default:
- dev_err(&master->dev,
- "spi-tx-bus-width %d not supported\n",
- value);
- spi_dev_put(spi);
- continue;
+ dev_warn(&master->dev,
+ "spi-tx-bus-width %d not supported\n",
+ value);
+ break;
}
}
@@ -1063,11 +1288,10 @@ static void of_register_spi_devices(struct spi_master *master)
spi->mode |= SPI_RX_QUAD;
break;
default:
- dev_err(&master->dev,
- "spi-rx-bus-width %d not supported\n",
- value);
- spi_dev_put(spi);
- continue;
+ dev_warn(&master->dev,
+ "spi-rx-bus-width %d not supported\n",
+ value);
+ break;
}
}
@@ -1355,6 +1579,8 @@ int spi_register_master(struct spi_master *master)
mutex_init(&master->bus_lock_mutex);
master->bus_lock_flag = 0;
init_completion(&master->xfer_completion);
+ if (!master->max_dma_len)
+ master->max_dma_len = INT_MAX;
/* register the device, then userspace will see it.
* registration fails if the bus ID is in use.
@@ -1551,7 +1777,7 @@ EXPORT_SYMBOL_GPL(spi_busnum_to_master);
*/
int spi_setup(struct spi_device *spi)
{
- unsigned bad_bits;
+ unsigned bad_bits, ugly_bits;
int status = 0;
/* check mode to prevent that DUAL and QUAD set at the same time
@@ -1571,6 +1797,15 @@ int spi_setup(struct spi_device *spi)
* that aren't supported with their current master
*/
bad_bits = spi->mode & ~spi->master->mode_bits;
+ ugly_bits = bad_bits &
+ (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
+ if (ugly_bits) {
+ dev_warn(&spi->dev,
+ "setup: ignoring unsupported mode bits %x\n",
+ ugly_bits);
+ spi->mode &= ~ugly_bits;
+ bad_bits &= ~ugly_bits;
+ }
if (bad_bits) {
dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
bad_bits);
@@ -1580,6 +1815,9 @@ int spi_setup(struct spi_device *spi)
if (!spi->bits_per_word)
spi->bits_per_word = 8;
+ if (!spi->max_speed_hz)
+ spi->max_speed_hz = spi->master->max_speed_hz;
+
if (spi->master->setup)
status = spi->master->setup(spi);
@@ -1596,19 +1834,14 @@ int spi_setup(struct spi_device *spi)
}
EXPORT_SYMBOL_GPL(spi_setup);
-static int __spi_async(struct spi_device *spi, struct spi_message *message)
+static int __spi_validate(struct spi_device *spi, struct spi_message *message)
{
struct spi_master *master = spi->master;
struct spi_transfer *xfer;
-
- message->spi = spi;
-
- trace_spi_message_submit(message);
+ int w_size;
if (list_empty(&message->transfers))
return -EINVAL;
- if (!message->complete)
- return -EINVAL;
/* Half-duplex links include original MicroWire, and ones with
* only one data pin like SPI_3WIRE (switches direction) or where
@@ -1639,12 +1872,13 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message)
message->frame_length += xfer->len;
if (!xfer->bits_per_word)
xfer->bits_per_word = spi->bits_per_word;
- if (!xfer->speed_hz) {
+
+ if (!xfer->speed_hz)
xfer->speed_hz = spi->max_speed_hz;
- if (master->max_speed_hz &&
- xfer->speed_hz > master->max_speed_hz)
- xfer->speed_hz = master->max_speed_hz;
- }
+
+ if (master->max_speed_hz &&
+ xfer->speed_hz > master->max_speed_hz)
+ xfer->speed_hz = master->max_speed_hz;
if (master->bits_per_word_mask) {
/* Only 32 bits fit in the mask */
@@ -1655,21 +1889,32 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message)
return -EINVAL;
}
+ /*
+ * SPI transfer length should be multiple of SPI word size
+ * where SPI word size should be power-of-two multiple
+ */
+ if (xfer->bits_per_word <= 8)
+ w_size = 1;
+ else if (xfer->bits_per_word <= 16)
+ w_size = 2;
+ else
+ w_size = 4;
+
+ /* No partial transfers accepted */
+ if (xfer->len % w_size)
+ return -EINVAL;
+
if (xfer->speed_hz && master->min_speed_hz &&
xfer->speed_hz < master->min_speed_hz)
return -EINVAL;
- if (xfer->speed_hz && master->max_speed_hz &&
- xfer->speed_hz > master->max_speed_hz)
- return -EINVAL;
if (xfer->tx_buf && !xfer->tx_nbits)
xfer->tx_nbits = SPI_NBITS_SINGLE;
if (xfer->rx_buf && !xfer->rx_nbits)
xfer->rx_nbits = SPI_NBITS_SINGLE;
/* check transfer tx/rx_nbits:
- * 1. keep the value is not out of single, dual and quad
- * 2. keep tx/rx_nbits is contained by mode in spi_device
- * 3. if SPI_3WIRE, tx/rx_nbits should be in single
+ * 1. check the value matches one of single, dual and quad
+ * 2. check tx/rx_nbits match the mode in spi_device
*/
if (xfer->tx_buf) {
if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
@@ -1682,9 +1927,6 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message)
if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
!(spi->mode & SPI_TX_QUAD))
return -EINVAL;
- if ((spi->mode & SPI_3WIRE) &&
- (xfer->tx_nbits != SPI_NBITS_SINGLE))
- return -EINVAL;
}
/* check transfer rx_nbits */
if (xfer->rx_buf) {
@@ -1698,13 +1940,22 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message)
if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
!(spi->mode & SPI_RX_QUAD))
return -EINVAL;
- if ((spi->mode & SPI_3WIRE) &&
- (xfer->rx_nbits != SPI_NBITS_SINGLE))
- return -EINVAL;
}
}
message->status = -EINPROGRESS;
+
+ return 0;
+}
+
+static int __spi_async(struct spi_device *spi, struct spi_message *message)
+{
+ struct spi_master *master = spi->master;
+
+ message->spi = spi;
+
+ trace_spi_message_submit(message);
+
return master->transfer(spi, message);
}
@@ -1743,6 +1994,10 @@ int spi_async(struct spi_device *spi, struct spi_message *message)
int ret;
unsigned long flags;
+ ret = __spi_validate(spi, message);
+ if (ret != 0)
+ return ret;
+
spin_lock_irqsave(&master->bus_lock_spinlock, flags);
if (master->bus_lock_flag)
@@ -1791,6 +2046,10 @@ int spi_async_locked(struct spi_device *spi, struct spi_message *message)
int ret;
unsigned long flags;
+ ret = __spi_validate(spi, message);
+ if (ret != 0)
+ return ret;
+
spin_lock_irqsave(&master->bus_lock_spinlock, flags);
ret = __spi_async(spi, message);