diff options
author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2008-10-09 21:33:05 +0100 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2008-10-09 21:33:05 +0100 |
commit | c97f68145e8067b3ac4b126a6faebf90f9ffc302 (patch) | |
tree | eb2060681552a00e9efa98224b95f69a3dc84390 /drivers/spi | |
parent | b1add0480a95b6ceaece5caf6c50614771eae9b2 (diff) | |
parent | 7bff3c4ce44ea48f50dc47a5994454984bd08c59 (diff) | |
download | linux-c97f68145e8067b3ac4b126a6faebf90f9ffc302.tar.bz2 |
Merge branch 'for-rmk' of git://source.mvista.com/git/linux-davinci-2.6.git
Merge branch 'davinci' into devel
Diffstat (limited to 'drivers/spi')
-rw-r--r-- | drivers/spi/pxa2xx_spi.c | 116 | ||||
-rw-r--r-- | drivers/spi/spi_mpc83xx.c | 26 | ||||
-rw-r--r-- | drivers/spi/spi_s3c24xx.c | 6 |
3 files changed, 110 insertions, 38 deletions
diff --git a/drivers/spi/pxa2xx_spi.c b/drivers/spi/pxa2xx_spi.c index 34c7c9875681..0e53354c1cfe 100644 --- a/drivers/spi/pxa2xx_spi.c +++ b/drivers/spi/pxa2xx_spi.c @@ -47,9 +47,10 @@ MODULE_ALIAS("platform:pxa2xx-spi"); #define MAX_BUSES 3 -#define DMA_INT_MASK (DCSR_ENDINTR | DCSR_STARTINTR | DCSR_BUSERR) -#define RESET_DMA_CHANNEL (DCSR_NODESC | DMA_INT_MASK) -#define IS_DMA_ALIGNED(x) (((u32)(x)&0x07)==0) +#define DMA_INT_MASK (DCSR_ENDINTR | DCSR_STARTINTR | DCSR_BUSERR) +#define RESET_DMA_CHANNEL (DCSR_NODESC | DMA_INT_MASK) +#define IS_DMA_ALIGNED(x) (((x) & 0x07) == 0) +#define MAX_DMA_LEN 8191 /* * for testing SSCR1 changes that require SSP restart, basically @@ -144,7 +145,6 @@ struct driver_data { size_t tx_map_len; u8 n_bytes; u32 dma_width; - int cs_change; int (*write)(struct driver_data *drv_data); int (*read)(struct driver_data *drv_data); irqreturn_t (*transfer_handler)(struct driver_data *drv_data); @@ -406,8 +406,45 @@ static void giveback(struct driver_data *drv_data) struct spi_transfer, transfer_list); + /* Delay if requested before any change in chip select */ + if (last_transfer->delay_usecs) + udelay(last_transfer->delay_usecs); + + /* Drop chip select UNLESS cs_change is true or we are returning + * a message with an error, or next message is for another chip + */ if (!last_transfer->cs_change) drv_data->cs_control(PXA2XX_CS_DEASSERT); + else { + struct spi_message *next_msg; + + /* Holding of cs was hinted, but we need to make sure + * the next message is for the same chip. Don't waste + * time with the following tests unless this was hinted. + * + * We cannot postpone this until pump_messages, because + * after calling msg->complete (below) the driver that + * sent the current message could be unloaded, which + * could invalidate the cs_control() callback... + */ + + /* get a pointer to the next message, if any */ + spin_lock_irqsave(&drv_data->lock, flags); + if (list_empty(&drv_data->queue)) + next_msg = NULL; + else + next_msg = list_entry(drv_data->queue.next, + struct spi_message, queue); + spin_unlock_irqrestore(&drv_data->lock, flags); + + /* see if the next and current messages point + * to the same chip + */ + if (next_msg && next_msg->spi != msg->spi) + next_msg = NULL; + if (!next_msg || msg->state == ERROR_STATE) + drv_data->cs_control(PXA2XX_CS_DEASSERT); + } msg->state = NULL; if (msg->complete) @@ -490,10 +527,9 @@ static void dma_transfer_complete(struct driver_data *drv_data) msg->actual_length += drv_data->len - (drv_data->rx_end - drv_data->rx); - /* Release chip select if requested, transfer delays are - * handled in pump_transfers */ - if (drv_data->cs_change) - drv_data->cs_control(PXA2XX_CS_DEASSERT); + /* Transfer delays and chip select release are + * handled in pump_transfers or giveback + */ /* Move to next transfer */ msg->state = next_transfer(drv_data); @@ -602,10 +638,9 @@ static void int_transfer_complete(struct driver_data *drv_data) drv_data->cur_msg->actual_length += drv_data->len - (drv_data->rx_end - drv_data->rx); - /* Release chip select if requested, transfer delays are - * handled in pump_transfers */ - if (drv_data->cs_change) - drv_data->cs_control(PXA2XX_CS_DEASSERT); + /* Transfer delays and chip select release are + * handled in pump_transfers or giveback + */ /* Move to next transfer */ drv_data->cur_msg->state = next_transfer(drv_data); @@ -840,23 +875,40 @@ static void pump_transfers(unsigned long data) return; } - /* Delay if requested at end of transfer*/ + /* Delay if requested at end of transfer before CS change */ if (message->state == RUNNING_STATE) { previous = list_entry(transfer->transfer_list.prev, struct spi_transfer, transfer_list); if (previous->delay_usecs) udelay(previous->delay_usecs); + + /* Drop chip select only if cs_change is requested */ + if (previous->cs_change) + drv_data->cs_control(PXA2XX_CS_DEASSERT); } - /* Check transfer length */ - if (transfer->len > 8191) - { - dev_warn(&drv_data->pdev->dev, "pump_transfers: transfer " - "length greater than 8191\n"); - message->status = -EINVAL; - giveback(drv_data); - return; + /* Check for transfers that need multiple DMA segments */ + if (transfer->len > MAX_DMA_LEN && chip->enable_dma) { + + /* reject already-mapped transfers; PIO won't always work */ + if (message->is_dma_mapped + || transfer->rx_dma || transfer->tx_dma) { + dev_err(&drv_data->pdev->dev, + "pump_transfers: mapped transfer length " + "of %lu is greater than %d\n", + transfer->len, MAX_DMA_LEN); + message->status = -EINVAL; + giveback(drv_data); + return; + } + + /* warn ... we force this to PIO mode */ + if (printk_ratelimit()) + dev_warn(&message->spi->dev, "pump_transfers: " + "DMA disabled for transfer length %ld " + "greater than %d\n", + (long)drv_data->len, MAX_DMA_LEN); } /* Setup the transfer state based on the type of transfer */ @@ -878,7 +930,6 @@ static void pump_transfers(unsigned long data) drv_data->len = transfer->len & DCMD_LENGTH; drv_data->write = drv_data->tx ? chip->write : null_writer; drv_data->read = drv_data->rx ? chip->read : null_reader; - drv_data->cs_change = transfer->cs_change; /* Change speed and bit per word on a per transfer */ cr0 = chip->cr0; @@ -925,7 +976,7 @@ static void pump_transfers(unsigned long data) &dma_thresh)) if (printk_ratelimit()) dev_warn(&message->spi->dev, - "pump_transfer: " + "pump_transfers: " "DMA burst size reduced to " "match bits_per_word\n"); } @@ -939,8 +990,23 @@ static void pump_transfers(unsigned long data) message->state = RUNNING_STATE; - /* Try to map dma buffer and do a dma transfer if successful */ - if ((drv_data->dma_mapped = map_dma_buffers(drv_data))) { + /* 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. + */ + drv_data->dma_mapped = 0; + if (drv_data->len > 0 && drv_data->len <= MAX_DMA_LEN) + drv_data->dma_mapped = map_dma_buffers(drv_data); + if (drv_data->dma_mapped) { /* Ensure we have the correct interrupt handler */ drv_data->transfer_handler = dma_transfer; diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c index 070c6219e2d6..ac0e3e4b3c54 100644 --- a/drivers/spi/spi_mpc83xx.c +++ b/drivers/spi/spi_mpc83xx.c @@ -267,16 +267,13 @@ int mpc83xx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) cs->hw_mode |= SPMODE_LEN(bits_per_word); if ((mpc83xx_spi->spibrg / hz) > 64) { + cs->hw_mode |= SPMODE_DIV16; pm = mpc83xx_spi->spibrg / (hz * 64); if (pm > 16) { - cs->hw_mode |= SPMODE_DIV16; - pm /= 16; - if (pm > 16) { - dev_err(&spi->dev, "Requested speed is too " - "low: %d Hz. Will use %d Hz instead.\n", - hz, mpc83xx_spi->spibrg / 1024); - pm = 16; - } + dev_err(&spi->dev, "Requested speed is too " + "low: %d Hz. Will use %d Hz instead.\n", + hz, mpc83xx_spi->spibrg / 1024); + pm = 16; } } else pm = mpc83xx_spi->spibrg / (hz * 4); @@ -315,11 +312,20 @@ static int mpc83xx_spi_bufs(struct spi_device *spi, struct spi_transfer *t) if (t->bits_per_word) bits_per_word = t->bits_per_word; len = t->len; - if (bits_per_word > 8) + if (bits_per_word > 8) { + /* invalid length? */ + if (len & 1) + return -EINVAL; len /= 2; - if (bits_per_word > 16) + } + if (bits_per_word > 16) { + /* invalid length? */ + if (len & 1) + return -EINVAL; len /= 2; + } mpc83xx_spi->count = len; + INIT_COMPLETION(mpc83xx_spi->done); /* enable rx ints */ diff --git a/drivers/spi/spi_s3c24xx.c b/drivers/spi/spi_s3c24xx.c index 98abc73c1a1d..3eb414b84a9d 100644 --- a/drivers/spi/spi_s3c24xx.c +++ b/drivers/spi/spi_s3c24xx.c @@ -430,7 +430,7 @@ static int s3c24xx_spi_resume(struct platform_device *pdev) #endif MODULE_ALIAS("platform:s3c2410-spi"); -static struct platform_driver s3c24xx_spidrv = { +static struct platform_driver s3c24xx_spi_driver = { .remove = __exit_p(s3c24xx_spi_remove), .suspend = s3c24xx_spi_suspend, .resume = s3c24xx_spi_resume, @@ -442,12 +442,12 @@ static struct platform_driver s3c24xx_spidrv = { static int __init s3c24xx_spi_init(void) { - return platform_driver_probe(&s3c24xx_spidrv, s3c24xx_spi_probe); + return platform_driver_probe(&s3c24xx_spi_driver, s3c24xx_spi_probe); } static void __exit s3c24xx_spi_exit(void) { - platform_driver_unregister(&s3c24xx_spidrv); + platform_driver_unregister(&s3c24xx_spi_driver); } module_init(s3c24xx_spi_init); |