diff options
| -rw-r--r-- | drivers/spi/amba-pl022.c | 516 | ||||
| -rw-r--r-- | include/linux/amba/pl022.h | 6 |
2 files changed, 434 insertions, 88 deletions
diff --git a/drivers/spi/amba-pl022.c b/drivers/spi/amba-pl022.c index 8cdddc97325c..db0c67908d2b 100644 --- a/drivers/spi/amba-pl022.c +++ b/drivers/spi/amba-pl022.c @@ -27,7 +27,6 @@ /* * TODO: * - add timeout on polled transfers - * - add generic DMA framework support */ #include <linux/init.h> @@ -45,6 +44,9 @@ #include <linux/amba/pl022.h> #include <linux/io.h> #include <linux/slab.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/scatterlist.h> /* * This macro is used to define some register default values. @@ -381,6 +383,14 @@ struct pl022 { enum ssp_reading read; enum ssp_writing write; u32 exp_fifo_level; + /* DMA settings */ +#ifdef CONFIG_DMA_ENGINE + struct dma_chan *dma_rx_channel; + struct dma_chan *dma_tx_channel; + struct sg_table sgt_rx; + struct sg_table sgt_tx; + char *dummypage; +#endif }; /** @@ -406,7 +416,7 @@ struct chip_data { u16 dmacr; u16 cpsr; u8 n_bytes; - u8 enable_dma:1; + bool enable_dma; enum ssp_reading read; enum ssp_writing write; void (*cs_control) (u32 command); @@ -763,6 +773,371 @@ static void *next_transfer(struct pl022 *pl022) } return STATE_DONE; } + +/* + * This DMA functionality is only compiled in if we have + * access to the generic DMA devices/DMA engine. + */ +#ifdef CONFIG_DMA_ENGINE +static void unmap_free_dma_scatter(struct pl022 *pl022) +{ + /* Unmap and free the SG tables */ + dma_unmap_sg(&pl022->adev->dev, pl022->sgt_tx.sgl, + pl022->sgt_tx.nents, DMA_TO_DEVICE); + dma_unmap_sg(&pl022->adev->dev, pl022->sgt_rx.sgl, + pl022->sgt_rx.nents, DMA_FROM_DEVICE); + sg_free_table(&pl022->sgt_rx); + sg_free_table(&pl022->sgt_tx); +} + +static void dma_callback(void *data) +{ + struct pl022 *pl022 = data; + struct spi_message *msg = pl022->cur_msg; + + BUG_ON(!pl022->sgt_rx.sgl); + +#ifdef VERBOSE_DEBUG + /* + * Optionally dump out buffers to inspect contents, this is + * good if you want to convince yourself that the loopback + * read/write contents are the same, when adopting to a new + * DMA engine. + */ + { + struct scatterlist *sg; + unsigned int i; + + dma_sync_sg_for_cpu(&pl022->adev->dev, + pl022->sgt_rx.sgl, + pl022->sgt_rx.nents, + DMA_FROM_DEVICE); + + for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) { + dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i); + print_hex_dump(KERN_ERR, "SPI RX: ", + DUMP_PREFIX_OFFSET, + 16, + 1, + sg_virt(sg), + sg_dma_len(sg), + 1); + } + for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) { + dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i); + print_hex_dump(KERN_ERR, "SPI TX: ", + DUMP_PREFIX_OFFSET, + 16, + 1, + sg_virt(sg), + sg_dma_len(sg), + 1); + } + } +#endif + + unmap_free_dma_scatter(pl022); + + /* Update total bytes transfered */ + msg->actual_length += pl022->cur_transfer->len; + if (pl022->cur_transfer->cs_change) + pl022->cur_chip-> + cs_control(SSP_CHIP_DESELECT); + + /* Move to next transfer */ + msg->state = next_transfer(pl022); + tasklet_schedule(&pl022->pump_transfers); +} + +static void setup_dma_scatter(struct pl022 *pl022, + void *buffer, + unsigned int length, + struct sg_table *sgtab) +{ + struct scatterlist *sg; + int bytesleft = length; + void *bufp = buffer; + int mapbytes; + int i; + + if (buffer) { + for_each_sg(sgtab->sgl, sg, sgtab->nents, i) { + /* + * If there are less bytes left than what fits + * in the current page (plus page alignment offset) + * we just feed in this, else we stuff in as much + * as we can. + */ + if (bytesleft < (PAGE_SIZE - offset_in_page(bufp))) + mapbytes = bytesleft; + else + mapbytes = PAGE_SIZE - offset_in_page(bufp); + sg_set_page(sg, virt_to_page(bufp), + mapbytes, offset_in_page(bufp)); + bufp += mapbytes; + bytesleft -= mapbytes; + dev_dbg(&pl022->adev->dev, + "set RX/TX target page @ %p, %d bytes, %d left\n", + bufp, mapbytes, bytesleft); + } + } else { + /* Map the dummy buffer on every page */ + for_each_sg(sgtab->sgl, sg, sgtab->nents, i) { + if (bytesleft < PAGE_SIZE) + mapbytes = bytesleft; + else + mapbytes = PAGE_SIZE; + sg_set_page(sg, virt_to_page(pl022->dummypage), + mapbytes, 0); + bytesleft -= mapbytes; + dev_dbg(&pl022->adev->dev, + "set RX/TX to dummy page %d bytes, %d left\n", + mapbytes, bytesleft); + + } + } + BUG_ON(bytesleft); +} + +/** + * configure_dma - configures the channels for the next transfer + * @pl022: SSP driver's private data structure + */ +static int configure_dma(struct pl022 *pl022) +{ + struct dma_slave_config rx_conf = { + .src_addr = SSP_DR(pl022->phybase), + .direction = DMA_FROM_DEVICE, + .src_maxburst = pl022->vendor->fifodepth >> 1, + }; + struct dma_slave_config tx_conf = { + .dst_addr = SSP_DR(pl022->phybase), + .direction = DMA_TO_DEVICE, + .dst_maxburst = pl022->vendor->fifodepth >> 1, + }; + unsigned int pages; + int ret; + int sglen; + struct dma_chan *rxchan = pl022->dma_rx_channel; + struct dma_chan *txchan = pl022->dma_tx_channel; + struct dma_async_tx_descriptor *rxdesc; + struct dma_async_tx_descriptor *txdesc; + dma_cookie_t cookie; + + /* Check that the channels are available */ + if (!rxchan || !txchan) + return -ENODEV; + + switch (pl022->read) { + case READING_NULL: + /* Use the same as for writing */ + rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED; + break; + case READING_U8: + rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + break; + case READING_U16: + rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; + break; + case READING_U32: + rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + break; + } + + switch (pl022->write) { + case WRITING_NULL: + /* Use the same as for reading */ + tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED; + break; + case WRITING_U8: + tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + break; + case WRITING_U16: + tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; + break; + case WRITING_U32: + tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;; + break; + } + + /* SPI pecularity: we need to read and write the same width */ + if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED) + rx_conf.src_addr_width = tx_conf.dst_addr_width; + if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED) + tx_conf.dst_addr_width = rx_conf.src_addr_width; + BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width); + + rxchan->device->device_control(rxchan, DMA_SLAVE_CONFIG, + (unsigned long) &rx_conf); + txchan->device->device_control(txchan, DMA_SLAVE_CONFIG, + (unsigned long) &tx_conf); + + /* Create sglists for the transfers */ + pages = (pl022->cur_transfer->len >> PAGE_SHIFT) + 1; + dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages); + + ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_KERNEL); + if (ret) + goto err_alloc_rx_sg; + + ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_KERNEL); + if (ret) + goto err_alloc_tx_sg; + + /* Fill in the scatterlists for the RX+TX buffers */ + setup_dma_scatter(pl022, pl022->rx, + pl022->cur_transfer->len, &pl022->sgt_rx); + setup_dma_scatter(pl022, pl022->tx, + pl022->cur_transfer->len, &pl022->sgt_tx); + + /* Map DMA buffers */ + sglen = dma_map_sg(&pl022->adev->dev, pl022->sgt_rx.sgl, + pl022->sgt_rx.nents, DMA_FROM_DEVICE); + if (!sglen) + goto err_rx_sgmap; + + sglen = dma_map_sg(&pl022->adev->dev, pl022->sgt_tx.sgl, + pl022->sgt_tx.nents, DMA_TO_DEVICE); + if (!sglen) + goto err_tx_sgmap; + + /* Send both scatterlists */ + rxdesc = rxchan->device->device_prep_slave_sg(rxchan, + pl022->sgt_rx.sgl, + pl022->sgt_rx.nents, + DMA_FROM_DEVICE, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!rxdesc) + goto err_rxdesc; + + txdesc = txchan->device->device_prep_slave_sg(txchan, + pl022->sgt_tx.sgl, + pl022->sgt_tx.nents, + DMA_TO_DEVICE, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!txdesc) + goto err_txdesc; + + /* Put the callback on the RX transfer only, that should finish last */ + rxdesc->callback = dma_callback; + rxdesc->callback_param = pl022; + + /* 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_submit_rx; + cookie = txdesc->tx_submit(txdesc); + if (dma_submit_error(cookie)) + goto err_submit_tx; + rxchan->device->device_issue_pending(rxchan); + txchan->device->device_issue_pending(txchan); + + return 0; + +err_submit_tx: +err_submit_rx: +err_txdesc: + txchan->device->device_control(txchan, DMA_TERMINATE_ALL, 0); +err_rxdesc: + rxchan->device->device_control(rxchan, DMA_TERMINATE_ALL, 0); + dma_unmap_sg(&pl022->adev->dev, pl022->sgt_tx.sgl, + pl022->sgt_tx.nents, DMA_TO_DEVICE); +err_tx_sgmap: + dma_unmap_sg(&pl022->adev->dev, pl022->sgt_rx.sgl, + pl022->sgt_tx.nents, DMA_FROM_DEVICE); +err_rx_sgmap: + sg_free_table(&pl022->sgt_tx); +err_alloc_tx_sg: + sg_free_table(&pl022->sgt_rx); +err_alloc_rx_sg: + return -ENOMEM; +} + +static int __init pl022_dma_probe(struct pl022 *pl022) +{ + dma_cap_mask_t mask; + + /* Try to acquire a generic DMA engine slave channel */ + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + /* + * We need both RX and TX channels to do DMA, else do none + * of them. + */ + pl022->dma_rx_channel = dma_request_channel(mask, + pl022->master_info->dma_filter, + pl022->master_info->dma_rx_param); + if (!pl022->dma_rx_channel) { + dev_err(&pl022->adev->dev, "no RX DMA channel!\n"); + goto err_no_rxchan; + } + + pl022->dma_tx_channel = dma_request_channel(mask, + pl022->master_info->dma_filter, + pl022->master_info->dma_tx_param); + if (!pl022->dma_tx_channel) { + dev_err(&pl022->adev->dev, "no TX DMA channel!\n"); + goto err_no_txchan; + } + + pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!pl022->dummypage) { + dev_err(&pl022->adev->dev, "no DMA dummypage!\n"); + goto err_no_dummypage; + } + + dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n", + dma_chan_name(pl022->dma_rx_channel), + dma_chan_name(pl022->dma_tx_channel)); + + return 0; + +err_no_dummypage: + dma_release_channel(pl022->dma_tx_channel); +err_no_txchan: + dma_release_channel(pl022->dma_rx_channel); + pl022->dma_rx_channel = NULL; +err_no_rxchan: + return -ENODEV; +} + +static void terminate_dma(struct pl022 *pl022) +{ + struct dma_chan *rxchan = pl022->dma_rx_channel; + struct dma_chan *txchan = pl022->dma_tx_channel; + + rxchan->device->device_control(rxchan, DMA_TERMINATE_ALL, 0); + txchan->device->device_control(txchan, DMA_TERMINATE_ALL, 0); + unmap_free_dma_scatter(pl022); +} + +static void pl022_dma_remove(struct pl022 *pl022) +{ + if (pl022->busy) + terminate_dma(pl022); + if (pl022->dma_tx_channel) + dma_release_channel(pl022->dma_tx_channel); + if (pl022->dma_rx_channel) + dma_release_channel(pl022->dma_rx_channel); + kfree(pl022->dummypage); +} + +#else +static inline int configure_dma(struct pl022 *pl022) +{ + return -ENODEV; +} + +static inline int pl022_dma_probe(struct pl022 *pl022) +{ + return 0; +} + +static inline void pl022_dma_remove(struct pl022 *pl022) +{ +} +#endif + /** * pl022_interrupt_handler - Interrupt handler for SSP controller * @@ -794,14 +1169,17 @@ static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id) if (unlikely(!irq_status)) return IRQ_NONE; - /* This handles the error code interrupts */ + /* + * This handles the FIFO interrupts, the timeout + * interrupts are flatly ignored, they cannot be + * trusted. + */ if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) { /* * Overrun interrupt - bail out since our Data has been * corrupted */ - dev_err(&pl022->adev->dev, - "FIFO overrun\n"); + dev_err(&pl022->adev->dev, "FIFO overrun\n"); if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF) dev_err(&pl022->adev->dev, "RXFIFO is full\n"); @@ -896,8 +1274,8 @@ static int set_up_next_transfer(struct pl022 *pl022, } /** - * pump_transfers - Tasklet function which schedules next interrupt transfer - * when running in interrupt transfer mode. + * pump_transfers - Tasklet function which schedules next transfer + * when running in interrupt or DMA transfer mode. * @data: SSP driver private data structure * */ @@ -954,65 +1332,23 @@ static void pump_transfers(unsigned long data) } /* Flush the FIFOs and let's go! */ flush(pl022); - writew(ENABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); -} - -/** - * NOT IMPLEMENTED - * configure_dma - It configures the DMA pipes for DMA transfers - * @data: SSP driver's private data structure - * - */ -static int configure_dma(void *data) -{ - struct pl022 *pl022 = data; - dev_dbg(&pl022->adev->dev, "configure DMA\n"); - return -ENOTSUPP; -} - -/** - * do_dma_transfer - It handles transfers of the current message - * if it is DMA xfer. - * NOT FULLY IMPLEMENTED - * @data: SSP driver's private data structure - */ -static void do_dma_transfer(void *data) -{ - struct pl022 *pl022 = data; - - if (configure_dma(data)) { - dev_dbg(&pl022->adev->dev, "configuration of DMA Failed!\n"); - goto err_config_dma; - } - /* TODO: Implememt DMA setup of pipes here */ - - /* Enable target chip, set up transfer */ - pl022->cur_chip->cs_control(SSP_CHIP_SELECT); - if (set_up_next_transfer(pl022, pl022->cur_transfer)) { - /* Error path */ - pl022->cur_msg->state = STATE_ERROR; - pl022->cur_msg->status = -EIO; - giveback(pl022); + if (pl022->cur_chip->enable_dma) { + if (configure_dma(pl022)) { + dev_dbg(&pl022->adev->dev, + "configuration of DMA failed, fall back to interrupt mode\n"); + goto err_config_dma; + } return; } - /* Enable SSP */ - writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE), - SSP_CR1(pl022->virtbase)); - - /* TODO: Enable the DMA transfer here */ - return; - err_config_dma: - pl022->cur_msg->state = STATE_ERROR; - pl022->cur_msg->status = -EIO; - giveback(pl022); - return; +err_config_dma: + writew(ENABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); } -static void do_interrupt_transfer(void *data) +static void do_interrupt_dma_transfer(struct pl022 *pl022) { - struct pl022 *pl022 = data; + u32 irqflags = ENABLE_ALL_INTERRUPTS; /* Enable target chip */ pl022->cur_chip->cs_control(SSP_CHIP_SELECT); @@ -1023,15 +1359,26 @@ static void do_interrupt_transfer(void *data) giveback(pl022); return; } + /* If we're using DMA, set up DMA here */ + if (pl022->cur_chip->enable_dma) { + /* Configure DMA transfer */ + if (configure_dma(pl022)) { + dev_dbg(&pl022->adev->dev, + "configuration of DMA failed, fall back to interrupt mode\n"); + goto err_config_dma; + } + /* Disable interrupts in DMA mode, IRQ from DMA controller */ + irqflags = DISABLE_ALL_INTERRUPTS; + } +err_config_dma: /* Enable SSP, turn on interrupts */ writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE), SSP_CR1(pl022->virtbase)); - writew(ENABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); + writew(irqflags, SSP_IMSC(pl022->virtbase)); } -static void do_polling_transfer(void *data) +static void do_polling_transfer(struct pl022 *pl022) { - struct pl022 *pl022 = data; struct spi_message *message = NULL; struct spi_transfer *transfer = NULL; struct spi_transfer *previous = NULL; @@ -1101,7 +1448,7 @@ static void do_polling_transfer(void *data) * * This function checks if there is any spi message in the queue that * needs processing and delegate control to appropriate function - * do_polling_transfer()/do_interrupt_transfer()/do_dma_transfer() + * do_polling_transfer()/do_interrupt_dma_transfer() * based on the kind of the transfer * */ @@ -1150,10 +1497,8 @@ static void pump_messages(struct work_struct *work) if (pl022->cur_chip->xfer_type == POLLING_TRANSFER) do_polling_transfer(pl022); - else if (pl022->cur_chip->xfer_type == INTERRUPT_TRANSFER) - do_interrupt_transfer(pl022); else - do_dma_transfer(pl022); + do_interrupt_dma_transfer(pl022); } @@ -1469,23 +1814,6 @@ static int calculate_effective_freq(struct pl022 *pl022, } /** - * NOT IMPLEMENTED - * process_dma_info - Processes the DMA info provided by client drivers - * @chip_info: chip info provided by client device - * @chip: Runtime state maintained by the SSP controller for each spi device - * - * This function processes and stores DMA config provided by client driver - * into the runtime state maintained by the SSP controller driver - */ -static int process_dma_info(struct pl022_config_chip *chip_info, - struct chip_data *chip) -{ - dev_err(chip_info->dev, - "cannot process DMA info, DMA not implemented!\n"); - return -ENOTSUPP; -} - -/** * pl022_setup - setup function registered to SPI master framework * @spi: spi device which is requesting setup * @@ -1552,8 +1880,6 @@ static int pl022_setup(struct spi_device *spi) dev_dbg(&spi->dev, "allocated memory for controller data\n"); - /* Pointer back to the SPI device */ - chip_info->dev = &spi->dev; /* * Set controller data default values: * Polling is supported by default @@ -1579,6 +1905,9 @@ static int pl022_setup(struct spi_device *spi) "using user supplied controller_data settings\n"); } + /* Pointer back to the SPI device */ + chip_info->dev = &spi->dev; + /* * We can override with custom divisors, else we use the board * frequency setting @@ -1637,9 +1966,8 @@ static int pl022_setup(struct spi_device *spi) chip->cpsr = 0; if ((chip_info->com_mode == DMA_TRANSFER) && ((pl022->master_info)->enable_dma)) { - chip->enable_dma = 1; + chip->enable_dma = true; dev_dbg(&spi->dev, "DMA mode set in controller state\n"); - status = process_dma_info(chip_info, chip); if (status < 0) goto err_config_params; SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED, @@ -1647,7 +1975,7 @@ static int pl022_setup(struct spi_device *spi) SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED, SSP_DMACR_MASK_TXDMAE, 1); } else { - chip->enable_dma = 0; + chip->enable_dma = false; dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n"); SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0); @@ -1773,6 +2101,7 @@ pl022_probe(struct amba_device *adev, struct amba_id *id) if (status) goto err_no_ioregion; + pl022->phybase = adev->res.start; pl022->virtbase = ioremap(adev->res.start, resource_size(&adev->res)); if (pl022->virtbase == NULL) { status = -ENOMEM; @@ -1799,6 +2128,14 @@ pl022_probe(struct amba_device *adev, struct amba_id *id) dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status); goto err_no_irq; } + + /* Get DMA channels */ + if (platform_info->enable_dma) { + status = pl022_dma_probe(pl022); + if (status != 0) + goto err_no_dma; + } + /* Initialize and start queue */ status = init_queue(pl022); if (status != 0) { @@ -1827,6 +2164,8 @@ pl022_probe(struct amba_device *adev, struct amba_id *id) err_start_queue: err_init_queue: destroy_queue(pl022); + pl022_dma_remove(pl022); + err_no_dma: free_irq(adev->irq[0], pl022); err_no_irq: clk_put(pl022->clk); @@ -1857,6 +2196,7 @@ pl022_remove(struct amba_device *adev) return status; } load_ssp_default_config(pl022); + pl022_dma_remove(pl022); free_irq(adev->irq[0], pl022); clk_disable(pl022->clk); clk_put(pl022->clk); diff --git a/include/linux/amba/pl022.h b/include/linux/amba/pl022.h index abf26cc47a2b..db6a191ddcf7 100644 --- a/include/linux/amba/pl022.h +++ b/include/linux/amba/pl022.h @@ -228,6 +228,7 @@ enum ssp_chip_select { }; +struct dma_chan; /** * struct pl022_ssp_master - device.platform_data for SPI controller devices. * @num_chipselect: chipselects are used to distinguish individual @@ -235,11 +236,16 @@ enum ssp_chip_select { * each slave has a chipselect signal, but it's common that not * every chipselect is connected to a slave. * @enable_dma: if true enables DMA driven transfers. + * @dma_rx_param: parameter to locate an RX DMA channel. + * @dma_tx_param: parameter to locate a TX DMA channel. */ struct pl022_ssp_controller { u16 bus_id; u8 num_chipselect; u8 enable_dma:1; + bool (*dma_filter)(struct dma_chan *chan, void *filter_param); + void *dma_rx_param; + void *dma_tx_param; }; /** |