diff options
Diffstat (limited to 'drivers/spi')
-rw-r--r-- | drivers/spi/Kconfig | 13 | ||||
-rw-r--r-- | drivers/spi/Makefile | 5 | ||||
-rw-r--r-- | drivers/spi/spi-pxa2xx-dma.c | 392 | ||||
-rw-r--r-- | drivers/spi/spi-pxa2xx-pxadma.c | 490 | ||||
-rw-r--r-- | drivers/spi/spi-pxa2xx.c | 908 | ||||
-rw-r--r-- | drivers/spi/spi-pxa2xx.h | 221 |
6 files changed, 1451 insertions, 578 deletions
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index a90393d7f106..e79884e997ae 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -297,9 +297,20 @@ config SPI_PPC4xx help This selects a driver for the PPC4xx SPI Controller. +config SPI_PXA2XX_PXADMA + bool "PXA2xx SSP legacy PXA DMA API support" + depends on SPI_PXA2XX && ARCH_PXA + help + Enable PXA private legacy DMA API support. Note that this is + deprecated in favor of generic DMA engine API. + +config SPI_PXA2XX_DMA + def_bool y + depends on SPI_PXA2XX && !SPI_PXA2XX_PXADMA + config SPI_PXA2XX tristate "PXA2xx SSP SPI master" - depends on ARCH_PXA || PCI + depends on ARCH_PXA || PCI || ACPI select PXA_SSP if ARCH_PXA help This enables using a PXA2xx or Sodaville SSP port as a SPI master diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 64e970ba261c..e53c30941340 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -47,7 +47,10 @@ obj-$(CONFIG_SPI_OMAP24XX) += spi-omap2-mcspi.o obj-$(CONFIG_SPI_ORION) += spi-orion.o obj-$(CONFIG_SPI_PL022) += spi-pl022.o obj-$(CONFIG_SPI_PPC4xx) += spi-ppc4xx.o -obj-$(CONFIG_SPI_PXA2XX) += spi-pxa2xx.o +spi-pxa2xx-platform-objs := spi-pxa2xx.o +spi-pxa2xx-platform-$(CONFIG_SPI_PXA2XX_PXADMA) += spi-pxa2xx-pxadma.o +spi-pxa2xx-platform-$(CONFIG_SPI_PXA2XX_DMA) += spi-pxa2xx-dma.o +obj-$(CONFIG_SPI_PXA2XX) += spi-pxa2xx-platform.o obj-$(CONFIG_SPI_PXA2XX_PCI) += spi-pxa2xx-pci.o obj-$(CONFIG_SPI_RSPI) += spi-rspi.o obj-$(CONFIG_SPI_S3C24XX) += spi-s3c24xx-hw.o diff --git a/drivers/spi/spi-pxa2xx-dma.c b/drivers/spi/spi-pxa2xx-dma.c new file mode 100644 index 000000000000..c735c5a008a2 --- /dev/null +++ b/drivers/spi/spi-pxa2xx-dma.c @@ -0,0 +1,392 @@ +/* + * PXA2xx SPI DMA engine support. + * + * Copyright (C) 2013, Intel Corporation + * Author: Mika Westerberg <mika.westerberg@linux.intel.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/init.h> +#include <linux/device.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/pxa2xx_ssp.h> +#include <linux/scatterlist.h> +#include <linux/sizes.h> +#include <linux/spi/spi.h> +#include <linux/spi/pxa2xx_spi.h> + +#include "spi-pxa2xx.h" + +static int pxa2xx_spi_map_dma_buffer(struct driver_data *drv_data, + enum dma_data_direction dir) +{ + int i, nents, len = drv_data->len; + struct scatterlist *sg; + struct device *dmadev; + struct sg_table *sgt; + void *buf, *pbuf; + + /* + * Some DMA controllers have problems transferring buffers that are + * not multiple of 4 bytes. So we truncate the transfer so that it + * is suitable for such controllers, and handle the trailing bytes + * manually after the DMA completes. + * + * REVISIT: It would be better if this information could be + * retrieved directly from the DMA device in a similar way than + * ->copy_align etc. is done. + */ + len = ALIGN(drv_data->len, 4); + + if (dir == DMA_TO_DEVICE) { + dmadev = drv_data->tx_chan->device->dev; + sgt = &drv_data->tx_sgt; + buf = drv_data->tx; + drv_data->tx_map_len = len; + } else { + dmadev = drv_data->rx_chan->device->dev; + sgt = &drv_data->rx_sgt; + buf = drv_data->rx; + drv_data->rx_map_len = len; + } + + nents = DIV_ROUND_UP(len, SZ_2K); + if (nents != sgt->nents) { + int ret; + + sg_free_table(sgt); + ret = sg_alloc_table(sgt, nents, GFP_KERNEL); + if (ret) + return ret; + } + + pbuf = buf; + for_each_sg(sgt->sgl, sg, sgt->nents, i) { + size_t bytes = min_t(size_t, len, SZ_2K); + + if (buf) + sg_set_buf(sg, pbuf, bytes); + else + sg_set_buf(sg, drv_data->dummy, bytes); + + pbuf += bytes; + len -= bytes; + } + + nents = dma_map_sg(dmadev, sgt->sgl, sgt->nents, dir); + if (!nents) + return -ENOMEM; + + return nents; +} + +static void pxa2xx_spi_unmap_dma_buffer(struct driver_data *drv_data, + enum dma_data_direction dir) +{ + struct device *dmadev; + struct sg_table *sgt; + + if (dir == DMA_TO_DEVICE) { + dmadev = drv_data->tx_chan->device->dev; + sgt = &drv_data->tx_sgt; + } else { + dmadev = drv_data->rx_chan->device->dev; + sgt = &drv_data->rx_sgt; + } + + dma_unmap_sg(dmadev, sgt->sgl, sgt->nents, dir); +} + +static void pxa2xx_spi_unmap_dma_buffers(struct driver_data *drv_data) +{ + if (!drv_data->dma_mapped) + return; + + pxa2xx_spi_unmap_dma_buffer(drv_data, DMA_FROM_DEVICE); + pxa2xx_spi_unmap_dma_buffer(drv_data, DMA_TO_DEVICE); + + drv_data->dma_mapped = 0; +} + +static void pxa2xx_spi_dma_transfer_complete(struct driver_data *drv_data, + bool error) +{ + struct spi_message *msg = drv_data->cur_msg; + + /* + * It is possible that one CPU is handling ROR interrupt and other + * just gets DMA completion. Calling pump_transfers() twice for the + * same transfer leads to problems thus we prevent concurrent calls + * by using ->dma_running. + */ + if (atomic_dec_and_test(&drv_data->dma_running)) { + void __iomem *reg = drv_data->ioaddr; + + /* + * If the other CPU is still handling the ROR interrupt we + * might not know about the error yet. So we re-check the + * ROR bit here before we clear the status register. + */ + if (!error) { + u32 status = read_SSSR(reg) & drv_data->mask_sr; + error = status & SSSR_ROR; + } + + /* Clear status & disable interrupts */ + write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg); + write_SSSR_CS(drv_data, drv_data->clear_sr); + if (!pxa25x_ssp_comp(drv_data)) + write_SSTO(0, reg); + + if (!error) { + pxa2xx_spi_unmap_dma_buffers(drv_data); + + /* Handle the last bytes of unaligned transfer */ + drv_data->tx += drv_data->tx_map_len; + drv_data->write(drv_data); + + drv_data->rx += drv_data->rx_map_len; + drv_data->read(drv_data); + + msg->actual_length += drv_data->len; + msg->state = pxa2xx_spi_next_transfer(drv_data); + } else { + /* In case we got an error we disable the SSP now */ + write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg); + + msg->state = ERROR_STATE; + } + + tasklet_schedule(&drv_data->pump_transfers); + } +} + +static void pxa2xx_spi_dma_callback(void *data) +{ + pxa2xx_spi_dma_transfer_complete(data, false); +} + +static struct dma_async_tx_descriptor * +pxa2xx_spi_dma_prepare_one(struct driver_data *drv_data, + enum dma_transfer_direction dir) +{ + struct pxa2xx_spi_master *pdata = drv_data->master_info; + struct chip_data *chip = drv_data->cur_chip; + enum dma_slave_buswidth width; + struct dma_slave_config cfg; + struct dma_chan *chan; + struct sg_table *sgt; + int nents, ret; + + switch (drv_data->n_bytes) { + case 1: + width = DMA_SLAVE_BUSWIDTH_1_BYTE; + break; + case 2: + width = DMA_SLAVE_BUSWIDTH_2_BYTES; + break; + default: + width = DMA_SLAVE_BUSWIDTH_4_BYTES; + break; + } + + memset(&cfg, 0, sizeof(cfg)); + cfg.direction = dir; + + if (dir == DMA_MEM_TO_DEV) { + cfg.dst_addr = drv_data->ssdr_physical; + cfg.dst_addr_width = width; + cfg.dst_maxburst = chip->dma_burst_size; + cfg.slave_id = pdata->tx_slave_id; + + sgt = &drv_data->tx_sgt; + nents = drv_data->tx_nents; + chan = drv_data->tx_chan; + } else { + cfg.src_addr = drv_data->ssdr_physical; + cfg.src_addr_width = width; + cfg.src_maxburst = chip->dma_burst_size; + cfg.slave_id = pdata->rx_slave_id; + + sgt = &drv_data->rx_sgt; + nents = drv_data->rx_nents; + chan = drv_data->rx_chan; + } + + ret = dmaengine_slave_config(chan, &cfg); + if (ret) { + dev_warn(&drv_data->pdev->dev, "DMA slave config failed\n"); + return NULL; + } + + return dmaengine_prep_slave_sg(chan, sgt->sgl, nents, dir, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); +} + +static bool pxa2xx_spi_dma_filter(struct dma_chan *chan, void *param) +{ + const struct pxa2xx_spi_master *pdata = param; + + return chan->chan_id == pdata->tx_chan_id || + chan->chan_id == pdata->rx_chan_id; +} + +bool pxa2xx_spi_dma_is_possible(size_t len) +{ + return len <= MAX_DMA_LEN; +} + +int pxa2xx_spi_map_dma_buffers(struct driver_data *drv_data) +{ + const struct chip_data *chip = drv_data->cur_chip; + int ret; + + if (!chip->enable_dma) + return 0; + + /* Don't bother with DMA if we can't do even a single burst */ + if (drv_data->len < chip->dma_burst_size) + return 0; + + ret = pxa2xx_spi_map_dma_buffer(drv_data, DMA_TO_DEVICE); + if (ret <= 0) { + dev_warn(&drv_data->pdev->dev, "failed to DMA map TX\n"); + return 0; + } + + drv_data->tx_nents = ret; + + ret = pxa2xx_spi_map_dma_buffer(drv_data, DMA_FROM_DEVICE); + if (ret <= 0) { + pxa2xx_spi_unmap_dma_buffer(drv_data, DMA_TO_DEVICE); + dev_warn(&drv_data->pdev->dev, "failed to DMA map RX\n"); + return 0; + } + + drv_data->rx_nents = ret; + return 1; +} + +irqreturn_t pxa2xx_spi_dma_transfer(struct driver_data *drv_data) +{ + u32 status; + + status = read_SSSR(drv_data->ioaddr) & drv_data->mask_sr; + if (status & SSSR_ROR) { + dev_err(&drv_data->pdev->dev, "FIFO overrun\n"); + + dmaengine_terminate_all(drv_data->rx_chan); + dmaengine_terminate_all(drv_data->tx_chan); + + pxa2xx_spi_dma_transfer_complete(drv_data, true); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +int pxa2xx_spi_dma_prepare(struct driver_data *drv_data, u32 dma_burst) +{ + struct dma_async_tx_descriptor *tx_desc, *rx_desc; + + tx_desc = pxa2xx_spi_dma_prepare_one(drv_data, DMA_MEM_TO_DEV); + if (!tx_desc) { + dev_err(&drv_data->pdev->dev, + "failed to get DMA TX descriptor\n"); + return -EBUSY; + } + + rx_desc = pxa2xx_spi_dma_prepare_one(drv_data, DMA_DEV_TO_MEM); + if (!rx_desc) { + dev_err(&drv_data->pdev->dev, + "failed to get DMA RX descriptor\n"); + return -EBUSY; + } + + /* We are ready when RX completes */ + rx_desc->callback = pxa2xx_spi_dma_callback; + rx_desc->callback_param = drv_data; + + dmaengine_submit(rx_desc); + dmaengine_submit(tx_desc); + return 0; +} + +void pxa2xx_spi_dma_start(struct driver_data *drv_data) +{ + dma_async_issue_pending(drv_data->rx_chan); + dma_async_issue_pending(drv_data->tx_chan); + + atomic_set(&drv_data->dma_running, 1); +} + +int pxa2xx_spi_dma_setup(struct driver_data *drv_data) +{ + struct pxa2xx_spi_master *pdata = drv_data->master_info; + dma_cap_mask_t mask; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + drv_data->dummy = devm_kzalloc(&drv_data->pdev->dev, SZ_2K, GFP_KERNEL); + if (!drv_data->dummy) + return -ENOMEM; + + drv_data->tx_chan = dma_request_channel(mask, pxa2xx_spi_dma_filter, + pdata); + if (!drv_data->tx_chan) + return -ENODEV; + + drv_data->rx_chan = dma_request_channel(mask, pxa2xx_spi_dma_filter, + pdata); + if (!drv_data->rx_chan) { + dma_release_channel(drv_data->tx_chan); + drv_data->tx_chan = NULL; + return -ENODEV; + } + + return 0; +} + +void pxa2xx_spi_dma_release(struct driver_data *drv_data) +{ + if (drv_data->rx_chan) { + dmaengine_terminate_all(drv_data->rx_chan); + dma_release_channel(drv_data->rx_chan); + sg_free_table(&drv_data->rx_sgt); + drv_data->rx_chan = NULL; + } + if (drv_data->tx_chan) { + dmaengine_terminate_all(drv_data->tx_chan); + dma_release_channel(drv_data->tx_chan); + sg_free_table(&drv_data->tx_sgt); + drv_data->tx_chan = NULL; + } +} + +void pxa2xx_spi_dma_resume(struct driver_data *drv_data) +{ +} + +int pxa2xx_spi_set_dma_burst_and_threshold(struct chip_data *chip, + struct spi_device *spi, + u8 bits_per_word, u32 *burst_code, + u32 *threshold) +{ + struct pxa2xx_spi_chip *chip_info = spi->controller_data; + + /* + * If the DMA burst size is given in chip_info we use that, + * otherwise we use the default. Also we use the default FIFO + * thresholds for now. + */ + *burst_code = chip_info ? chip_info->dma_burst_size : 16; + *threshold = SSCR1_RxTresh(RX_THRESH_DFLT) + | SSCR1_TxTresh(TX_THRESH_DFLT); + + return 0; +} diff --git a/drivers/spi/spi-pxa2xx-pxadma.c b/drivers/spi/spi-pxa2xx-pxadma.c new file mode 100644 index 000000000000..2916efc7cfe5 --- /dev/null +++ b/drivers/spi/spi-pxa2xx-pxadma.c @@ -0,0 +1,490 @@ +/* + * PXA2xx SPI private DMA support. + * + * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/dma-mapping.h> +#include <linux/pxa2xx_ssp.h> +#include <linux/spi/spi.h> +#include <linux/spi/pxa2xx_spi.h> + +#include "spi-pxa2xx.h" + +#define DMA_INT_MASK (DCSR_ENDINTR | DCSR_STARTINTR | DCSR_BUSERR) +#define RESET_DMA_CHANNEL (DCSR_NODESC | DMA_INT_MASK) + +bool pxa2xx_spi_dma_is_possible(size_t len) +{ + /* Try to map dma buffer and do a dma transfer if successful, but + * only if the length is non-zero and less than MAX_DMA_LEN. + * + * Zero-length non-descriptor DMA is illegal on PXA2xx; force use + * of PIO instead. Care is needed above because the transfer may + * have have been passed with buffers that are already dma mapped. + * A zero-length transfer in PIO mode will not try to write/read + * to/from the buffers + * + * REVISIT large transfers are exactly where we most want to be + * using DMA. If this happens much, split those transfers into + * multiple DMA segments rather than forcing PIO. + */ + return len > 0 && len <= MAX_DMA_LEN; +} + +int pxa2xx_spi_map_dma_buffers(struct driver_data *drv_data) +{ + struct spi_message *msg = drv_data->cur_msg; + struct device *dev = &msg->spi->dev; + + if (!drv_data->cur_chip->enable_dma) + return 0; + + if (msg->is_dma_mapped) + return drv_data->rx_dma && drv_data->tx_dma; + + if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx)) + return 0; + + /* Modify setup if rx buffer is null */ + if (drv_data->rx == NULL) { + *drv_data->null_dma_buf = 0; + drv_data->rx = drv_data->null_dma_buf; + drv_data->rx_map_len = 4; + } else + drv_data->rx_map_len = drv_data->len; + + + /* Modify setup if tx buffer is null */ + if (drv_data->tx == NULL) { + *drv_data->null_dma_buf = 0; + drv_data->tx = drv_data->null_dma_buf; + drv_data->tx_map_len = 4; + } else + drv_data->tx_map_len = drv_data->len; + + /* Stream map the tx buffer. Always do DMA_TO_DEVICE first + * so we flush the cache *before* invalidating it, in case + * the tx and rx buffers overlap. + */ + drv_data->tx_dma = dma_map_single(dev, drv_data->tx, + drv_data->tx_map_len, DMA_TO_DEVICE); + if (dma_mapping_error(dev, drv_data->tx_dma)) + return 0; + + /* Stream map the rx buffer */ + drv_data->rx_dma = dma_map_single(dev, drv_data->rx, + drv_data->rx_map_len, DMA_FROM_DEVICE); + if (dma_mapping_error(dev, drv_data->rx_dma)) { + dma_unmap_single(dev, drv_data->tx_dma, + drv_data->tx_map_len, DMA_TO_DEVICE); + return 0; + } + + return 1; +} + +static void pxa2xx_spi_unmap_dma_buffers(struct driver_data *drv_data) +{ + struct device *dev; + + if (!drv_data->dma_mapped) + return; + + if (!drv_data->cur_msg->is_dma_mapped) { + dev = &drv_data->cur_msg->spi->dev; + dma_unmap_single(dev, drv_data->rx_dma, + drv_data->rx_map_len, DMA_FROM_DEVICE); + dma_unmap_single(dev, drv_data->tx_dma, + drv_data->tx_map_len, DMA_TO_DEVICE); + } + + drv_data->dma_mapped = 0; +} + +static int wait_ssp_rx_stall(void const __iomem *ioaddr) +{ + unsigned long limit = loops_per_jiffy << 1; + + while ((read_SSSR(ioaddr) & SSSR_BSY) && --limit) + cpu_relax(); + + return limit; +} + +static int wait_dma_channel_stop(int channel) +{ + unsigned long limit = loops_per_jiffy << 1; + + while (!(DCSR(channel) & DCSR_STOPSTATE) && --limit) + cpu_relax(); + + return limit; +} + +static void pxa2xx_spi_dma_error_stop(struct driver_data *drv_data, + const char *msg) +{ + void __iomem *reg = drv_data->ioaddr; + + /* Stop and reset */ + DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; + DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; + write_SSSR_CS(drv_data, drv_data->clear_sr); + write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg); + if (!pxa25x_ssp_comp(drv_data)) + write_SSTO(0, reg); + pxa2xx_spi_flush(drv_data); + write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg); + + pxa2xx_spi_unmap_dma_buffers(drv_data); + + dev_err(&drv_data->pdev->dev, "%s\n", msg); + + drv_data->cur_msg->state = ERROR_STATE; + tasklet_schedule(&drv_data->pump_transfers); +} + +static void pxa2xx_spi_dma_transfer_complete(struct driver_data *drv_data) +{ + void __iomem *reg = drv_data->ioaddr; + struct spi_message *msg = drv_data->cur_msg; + + /* Clear and disable interrupts on SSP and DMA channels*/ + write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg); + write_SSSR_CS(drv_data, drv_data->clear_sr); + DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; + DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; + + if (wait_dma_channel_stop(drv_data->rx_channel) == 0) + dev_err(&drv_data->pdev->dev, + "dma_handler: dma rx channel stop failed\n"); + + if (wait_ssp_rx_stall(drv_data->ioaddr) == 0) + dev_err(&drv_data->pdev->dev, + "dma_transfer: ssp rx stall failed\n"); + + pxa2xx_spi_unmap_dma_buffers(drv_data); + + /* update the buffer pointer for the amount completed in dma */ + drv_data->rx += drv_data->len - + (DCMD(drv_data->rx_channel) & DCMD_LENGTH); + + /* read trailing data from fifo, it does not matter how many + * bytes are in the fifo just read until buffer is full + * or fifo is empty, which ever occurs first */ + drv_data->read(drv_data); + + /* return count of what was actually read */ + msg->actual_length += drv_data->len - + (drv_data->rx_end - drv_data->rx); + + /* Transfer delays and chip select release are + * handled in pump_transfers or giveback + */ + + /* Move to next transfer */ + msg->state = pxa2xx_spi_next_transfer(drv_data); + + /* Schedule transfer tasklet */ + tasklet_schedule(&drv_data->pump_transfers); +} + +void pxa2xx_spi_dma_handler(int channel, void *data) +{ + struct driver_data *drv_data = data; + u32 irq_status = DCSR(channel) & DMA_INT_MASK; + + if (irq_status & DCSR_BUSERR) { + + if (channel == drv_data->tx_channel) + pxa2xx_spi_dma_error_stop(drv_data, + "dma_handler: bad bus address on tx channel"); + else + pxa2xx_spi_dma_error_stop(drv_data, + "dma_handler: bad bus address on rx channel"); + return; + } + + /* PXA255x_SSP has no timeout interrupt, wait for tailing bytes */ + if ((channel == drv_data->tx_channel) + && (irq_status & DCSR_ENDINTR) + && (drv_data->ssp_type == PXA25x_SSP)) { + + /* Wait for rx to stall */ + if (wait_ssp_rx_stall(drv_data->ioaddr) == 0) + dev_err(&drv_data->pdev->dev, + "dma_handler: ssp rx stall failed\n"); + + /* finish this transfer, start the next */ + pxa2xx_spi_dma_transfer_complete(drv_data); + } +} + +irqreturn_t pxa2xx_spi_dma_transfer(struct driver_data *drv_data) +{ + u32 irq_status; + void __iomem *reg = drv_data->ioaddr; + + irq_status = read_SSSR(reg) & drv_data->mask_sr; + if (irq_status & SSSR_ROR) { + pxa2xx_spi_dma_error_stop(drv_data, + "dma_transfer: fifo overrun"); + return IRQ_HANDLED; + } + + /* Check for false positive timeout */ + if ((irq_status & SSSR_TINT) + && (DCSR(drv_data->tx_channel) & DCSR_RUN)) { + write_SSSR(SSSR_TINT, reg); + return IRQ_HANDLED; + } + + if (irq_status & SSSR_TINT || drv_data->rx == drv_data->rx_end) { + + /* Clear and disable timeout interrupt, do the rest in + * dma_transfer_complete */ + if (!pxa25x_ssp_comp(drv_data)) + write_SSTO(0, reg); + + /* finish this transfer, start the next */ + pxa2xx_spi_dma_transfer_complete(drv_data); + + return IRQ_HANDLED; + } + + /* Opps problem detected */ + return IRQ_NONE; +} + +int pxa2xx_spi_dma_prepare(struct driver_data *drv_data, u32 dma_burst) +{ + u32 dma_width; + + switch (drv_data->n_bytes) { + case 1: + dma_width = DCMD_WIDTH1; + break; + case 2: + dma_width = DCMD_WIDTH2; + break; + default: + dma_width = DCMD_WIDTH4; + break; + } + + /* Setup rx DMA Channel */ + DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; + DSADR(drv_data->rx_channel) = drv_data->ssdr_physical; + DTADR(drv_data->rx_channel) = drv_data->rx_dma; + if (drv_data->rx == drv_data->null_dma_buf) + /* No target address increment */ + DCMD(drv_data->rx_channel) = DCMD_FLOWSRC + | dma_width + | dma_burst + | drv_data->len; + else + DCMD(drv_data->rx_channel) = DCMD_INCTRGADDR + | DCMD_FLOWSRC + | dma_width + | dma_burst + | drv_data->len; + + /* Setup tx DMA Channel */ + DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; + DSADR(drv_data->tx_channel) = drv_data->tx_dma; + DTADR(drv_data->tx_channel) = drv_data->ssdr_physical; + if (drv_data->tx == drv_data->null_dma_buf) + /* No source address increment */ + DCMD(drv_data->tx_channel) = DCMD_FLOWTRG + | dma_width + | dma_burst + | drv_data->len; + else + DCMD(drv_data->tx_channel) = DCMD_INCSRCADDR + | DCMD_FLOWTRG + | dma_width + | dma_burst + | drv_data->len; + + /* Enable dma end irqs on SSP to detect end of transfer */ + if (drv_data->ssp_type == PXA25x_SSP) + DCMD(drv_data->tx_channel) |= DCMD_ENDIRQEN; + + return 0; +} + +void pxa2xx_spi_dma_start(struct driver_data *drv_data) +{ + DCSR(drv_data->rx_channel) |= DCSR_RUN; + DCSR(drv_data->tx_channel) |= DCSR_RUN; +} + +int pxa2xx_spi_dma_setup(struct driver_data *drv_data) +{ + struct device *dev = &drv_data->pdev->dev; + struct ssp_device *ssp = drv_data->ssp; + + /* Get two DMA channels (rx and tx) */ + drv_data->rx_channel = pxa_request_dma("pxa2xx_spi_ssp_rx", + DMA_PRIO_HIGH, + pxa2xx_spi_dma_handler, + drv_data); + if (drv_data->rx_channel < 0) { + dev_err(dev, "problem (%d) requesting rx channel\n", + drv_data->rx_channel); + return -ENODEV; + } + drv_data->tx_channel = pxa_request_dma("pxa2xx_spi_ssp_tx", + DMA_PRIO_MEDIUM, + pxa2xx_spi_dma_handler, + drv_data); + if (drv_data->tx_channel < 0) { + dev_err(dev, "problem (%d) requesting tx channel\n", + drv_data->tx_channel); + pxa_free_dma(drv_data->rx_channel); + return -ENODEV; + } + + DRCMR(ssp->drcmr_rx) = DRCMR_MAPVLD | drv_data->rx_channel; + DRCMR(ssp->drcmr_tx) = DRCMR_MAPVLD | drv_data->tx_channel; + + return 0; +} + +void pxa2xx_spi_dma_release(struct driver_data *drv_data) +{ + struct ssp_device *ssp = drv_data->ssp; + + DRCMR(ssp->drcmr_rx) = 0; + DRCMR(ssp->drcmr_tx) = 0; + + if (drv_data->tx_channel != 0) + pxa_free_dma(drv_data->tx_channel); + if (drv_data->rx_channel != 0) + pxa_free_dma(drv_data->rx_channel); +} + +void pxa2xx_spi_dma_resume(struct driver_data *drv_data) +{ + if (drv_data->rx_channel != -1) + DRCMR(drv_data->ssp->drcmr_rx) = + DRCMR_MAPVLD | drv_data->rx_channel; + if (drv_data->tx_channel != -1) + DRCMR(drv_data->ssp->drcmr_tx) = + DRCMR_MAPVLD | drv_data->tx_channel; +} + +int pxa2xx_spi_set_dma_burst_and_threshold(struct chip_data *chip, + struct spi_device *spi, + u8 bits_per_word, u32 *burst_code, + u32 *threshold) +{ + struct pxa2xx_spi_chip *chip_info = + (struct pxa2xx_spi_chip *)spi->controller_data; + int bytes_per_word; + int burst_bytes; + int thresh_words; + int req_burst_size; + int retval = 0; + + /* Set the threshold (in registers) to equal the same amount of data + * as represented by burst size (in bytes). The computation below + * is (burst_size rounded up to nearest 8 byte, word or long word) + * divided by (bytes/register); the tx threshold is the inverse of + * the rx, so that there will always be enough data in the rx fifo + * to satisfy a burst, and there will always be enough space in the + * tx fifo to accept a burst (a tx burst will overwrite the fifo if + * there is not enough space), there must always remain enough empty + * space in the rx fifo for any data loaded to the tx fifo. + * Whenever burst_size (in bytes) equals bits/word, the fifo threshold + * will be 8, or half the fifo; + * The threshold can only be set to 2, 4 or 8, but not 16, because + * to burst 16 to the tx fifo, the fifo would have to be empty; + * however, the minimum fifo trigger level is 1, and the tx will + * request service when the fifo is at this level, with only 15 spaces. + */ + + /* find bytes/word */ + if (bits_per_word <= 8) + bytes_per_word = 1; + else if (bits_per_word <= 16) + bytes_per_word = 2; + else + bytes_per_word = 4; + + /* use struct pxa2xx_spi_chip->dma_burst_size if available */ + if (chip_info) + req_burst_size = chip_info->dma_burst_size; + else { + switch (chip->dma_burst_size) { + default: + /* if the default burst size is not set, + * do it now */ + chip->dma_burst_size = DCMD_BURST8; + case DCMD_BURST8: + req_burst_size = 8; + break; + case DCMD_BURST16: + req_burst_size = 16; + break; + case DCMD_BURST32: + req_burst_size = 32; + break; + } + } + if (req_burst_size <= 8) { + *burst_code = DCMD_BURST8; + burst_bytes = 8; + } else if (req_burst_size <= 16) { + if (bytes_per_word == 1) { + /* don't burst more than 1/2 the fifo */ + *burst_code = DCMD_BURST8; + burst_bytes = 8; + retval = 1; + } else { + *burst_code = DCMD_BURST16; + burst_bytes = 16; + } + } else { + if (bytes_per_word == 1) { + /* don't burst more than 1/2 the fifo */ + *burst_code = DCMD_BURST8; + burst_bytes = 8; + retval = 1; + } else if (bytes_per_word == 2) { + /* don't burst more than 1/2 the fifo */ + *burst_code = DCMD_BURST16; + burst_bytes = 16; + retval = 1; + } else { + *burst_code = DCMD_BURST32; + burst_bytes = 32; + } + } + + thresh_words = burst_bytes / bytes_per_word; + + /* thresh_words will be between 2 and 8 */ + *threshold = (SSCR1_RxTresh(thresh_words) & SSCR1_RFT) + | (SSCR1_TxTresh(16-thresh_words) & SSCR1_TFT); + + return retval; +} diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index 304cf6eb50e6..90b27a3508a6 100644 --- a/drivers/spi/spi-pxa2xx.c +++ b/drivers/spi/spi-pxa2xx.c @@ -1,5 +1,6 @@ /* * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs + * Copyright (C) 2013, Intel Corporation * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -24,18 +25,20 @@ #include <linux/interrupt.h> #include <linux/platform_device.h> #include <linux/spi/pxa2xx_spi.h> -#include <linux/dma-mapping.h> #include <linux/spi/spi.h> #include <linux/workqueue.h> #include <linux/delay.h> #include <linux/gpio.h> #include <linux/slab.h> #include <linux/clk.h> +#include <linux/pm_runtime.h> +#include <linux/acpi.h> #include <asm/io.h> #include <asm/irq.h> #include <asm/delay.h> +#include "spi-pxa2xx.h" MODULE_AUTHOR("Stephen Street"); MODULE_DESCRIPTION("PXA2xx SSP SPI Controller"); @@ -46,12 +49,6 @@ MODULE_ALIAS("platform:pxa2xx-spi"); #define TIMOUT_DFLT 1000 -#define DMA_INT_MASK (DCSR_ENDINTR | DCSR_STARTINTR | DCSR_BUSERR) -#define RESET_DMA_CHANNEL (DCSR_NODESC | DMA_INT_MASK) -#define IS_DMA_ALIGNED(x) IS_ALIGNED((unsigned long)(x), DMA_ALIGNMENT) -#define MAX_DMA_LEN 8191 -#define DMA_ALIGNMENT 8 - /* * for testing SSCR1 changes that require SSP restart, basically * everything except the service and interrupt enables, the pxa270 developer @@ -66,105 +63,97 @@ MODULE_ALIAS("platform:pxa2xx-spi"); | SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \ | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM) -#define DEFINE_SSP_REG(reg, off) \ -static inline u32 read_##reg(void const __iomem *p) \ -{ return __raw_readl(p + (off)); } \ -\ -static inline void write_##reg(u32 v, void __iomem *p) \ -{ __raw_writel(v, p + (off)); } - -DEFINE_SSP_REG(SSCR0, 0x00) -DEFINE_SSP_REG(SSCR1, 0x04) -DEFINE_SSP_REG(SSSR, 0x08) -DEFINE_SSP_REG(SSITR, 0x0c) -DEFINE_SSP_REG(SSDR, 0x10) -DEFINE_SSP_REG(SSTO, 0x28) -DEFINE_SSP_REG(SSPSP, 0x2c) - -#define START_STATE ((void*)0) -#define RUNNING_STATE ((void*)1) -#define DONE_STATE ((void*)2) -#define ERROR_STATE ((void*)-1) - -struct driver_data { - /* Driver model hookup */ - struct platform_device *pdev; - - /* SSP Info */ - struct ssp_device *ssp; +#define LPSS_RX_THRESH_DFLT 64 +#define LPSS_TX_LOTHRESH_DFLT 160 +#define LPSS_TX_HITHRESH_DFLT 224 - /* SPI framework hookup */ - enum pxa_ssp_type ssp_type; - struct spi_master *master; +/* Offset from drv_data->lpss_base */ +#define SPI_CS_CONTROL 0x18 +#define SPI_CS_CONTROL_SW_MODE BIT(0) +#define SPI_CS_CONTROL_CS_HIGH BIT(1) - /* PXA hookup */ - struct pxa2xx_spi_master *master_info; - - /* DMA setup stuff */ - int rx_channel; - int tx_channel; - u32 *null_dma_buf; - - /* SSP register addresses */ - void __iomem *ioaddr; - u32 ssdr_physical; - - /* SSP masks*/ - u32 dma_cr1; - u32 int_cr1; - u32 clear_sr; - u32 mask_sr; - - /* Maximun clock rate */ - unsigned long max_clk_rate; - - /* Message Transfer pump */ - struct tasklet_struct pump_transfers; - - /* Current message transfer state info */ - struct spi_message* cur_msg; - struct spi_transfer* cur_transfer; - struct chip_data *cur_chip; - size_t len; - void *tx; - void *tx_end; - void *rx; - void *rx_end; - int dma_mapped; - dma_addr_t rx_dma; - dma_addr_t tx_dma; - size_t rx_map_len; - size_t tx_map_len; - u8 n_bytes; - u32 dma_width; - int (*write)(struct driver_data *drv_data); - int (*read)(struct driver_data *drv_data); - irqreturn_t (*transfer_handler)(struct driver_data *drv_data); - void (*cs_control)(u32 command); -}; +static bool is_lpss_ssp(const struct driver_data *drv_data) +{ + return drv_data->ssp_type == LPSS_SSP; +} -struct chip_data { - u32 cr0; - u32 cr1; - u32 psp; - u32 timeout; - u8 n_bytes; - u32 dma_width; - u32 dma_burst_size; - u32 threshold; - u32 dma_threshold; - u8 enable_dma; - u8 bits_per_word; - u32 speed_hz; - union { - int gpio_cs; - unsigned int frm; - }; - int gpio_cs_inverted; - int (*write)(struct driver_data *drv_data); - int (*read)(struct driver_data *drv_data); - void (*cs_control)(u32 command); -}; +/* + * Read and write LPSS SSP private registers. Caller must first check that + * is_lpss_ssp() returns true before these can be called. + */ +static u32 __lpss_ssp_read_priv(struct driver_data *drv_data, unsigned offset) +{ + WARN_ON(!drv_data->lpss_base); + return readl(drv_data->lpss_base + offset); +} + +static void __lpss_ssp_write_priv(struct driver_data *drv_data, + unsigned offset, u32 value) +{ + WARN_ON(!drv_data->lpss_base); + writel(value, drv_data->lpss_base + offset); +} + +/* + * lpss_ssp_setup - perform LPSS SSP specific setup + * @drv_data: pointer to the driver private data + * + * Perform LPSS SSP specific setup. This function must be called first if + * one is going to use LPSS SSP private registers. + */ +static void lpss_ssp_setup(struct driver_data *drv_data) +{ + unsigned offset = 0x400; + u32 value, orig; + + if (!is_lpss_ssp(drv_data)) + return; + + /* + * Perform auto-detection of the LPSS SSP private registers. They + * can be either at 1k or 2k offset from the base address. + */ + orig = readl(drv_data->ioaddr + offset + SPI_CS_CONTROL); + + value = orig | SPI_CS_CONTROL_SW_MODE; + writel(value, drv_data->ioaddr + offset + SPI_CS_CONTROL); |