diff options
Diffstat (limited to 'drivers/spi/spi.c')
| -rw-r--r-- | drivers/spi/spi.c | 383 |
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); |
