diff options
Diffstat (limited to 'drivers/spi/spi-atmel.c')
| -rw-r--r-- | drivers/spi/spi-atmel.c | 324 |
1 files changed, 142 insertions, 182 deletions
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c index 8feac599e9ab..0e7712bac3b6 100644 --- a/drivers/spi/spi-atmel.c +++ b/drivers/spi/spi-atmel.c @@ -24,6 +24,7 @@ #include <linux/io.h> #include <linux/gpio.h> +#include <linux/of_gpio.h> #include <linux/pinctrl/consumer.h> #include <linux/pm_runtime.h> @@ -264,17 +265,6 @@ #define AUTOSUSPEND_TIMEOUT 2000 -struct atmel_spi_dma { - struct dma_chan *chan_rx; - struct dma_chan *chan_tx; - struct scatterlist sgrx; - struct scatterlist sgtx; - struct dma_async_tx_descriptor *data_desc_rx; - struct dma_async_tx_descriptor *data_desc_tx; - - struct at_dma_slave dma_slave; -}; - struct atmel_spi_caps { bool is_spi2; bool has_wdrbt; @@ -295,6 +285,7 @@ struct atmel_spi { int irq; struct clk *clk; struct platform_device *pdev; + unsigned long spi_clk; struct spi_transfer *current_transfer; int current_remaining_bytes; @@ -302,17 +293,11 @@ struct atmel_spi { struct completion xfer_completion; - /* scratch buffer */ - void *buffer; - dma_addr_t buffer_dma; - struct atmel_spi_caps caps; bool use_dma; bool use_pdc; bool use_cs_gpios; - /* dmaengine data */ - struct atmel_spi_dma dma; bool keep_cs; bool cs_active; @@ -326,7 +311,7 @@ struct atmel_spi_device { u32 csr; }; -#define BUFFER_SIZE PAGE_SIZE +#define SPI_MAX_DMA_XFER 65535 /* true for both PDC and DMA */ #define INVALID_DMA_ADDRESS 0xffffffff /* @@ -456,10 +441,20 @@ static inline bool atmel_spi_use_dma(struct atmel_spi *as, return as->use_dma && xfer->len >= DMA_MIN_BYTES; } +static bool atmel_spi_can_dma(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *xfer) +{ + struct atmel_spi *as = spi_master_get_devdata(master); + + return atmel_spi_use_dma(as, xfer); +} + static int atmel_spi_dma_slave_config(struct atmel_spi *as, struct dma_slave_config *slave_config, u8 bits_per_word) { + struct spi_master *master = platform_get_drvdata(as->pdev); int err = 0; if (bits_per_word > 8) { @@ -491,7 +486,7 @@ static int atmel_spi_dma_slave_config(struct atmel_spi *as, * path works the same whether FIFOs are available (and enabled) or not. */ slave_config->direction = DMA_MEM_TO_DEV; - if (dmaengine_slave_config(as->dma.chan_tx, slave_config)) { + if (dmaengine_slave_config(master->dma_tx, slave_config)) { dev_err(&as->pdev->dev, "failed to configure tx dma channel\n"); err = -EINVAL; @@ -506,7 +501,7 @@ static int atmel_spi_dma_slave_config(struct atmel_spi *as, * enabled) or not. */ slave_config->direction = DMA_DEV_TO_MEM; - if (dmaengine_slave_config(as->dma.chan_rx, slave_config)) { + if (dmaengine_slave_config(master->dma_rx, slave_config)) { dev_err(&as->pdev->dev, "failed to configure rx dma channel\n"); err = -EINVAL; @@ -515,7 +510,8 @@ static int atmel_spi_dma_slave_config(struct atmel_spi *as, return err; } -static int atmel_spi_configure_dma(struct atmel_spi *as) +static int atmel_spi_configure_dma(struct spi_master *master, + struct atmel_spi *as) { struct dma_slave_config slave_config; struct device *dev = &as->pdev->dev; @@ -525,26 +521,26 @@ static int atmel_spi_configure_dma(struct atmel_spi *as) dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask); - as->dma.chan_tx = dma_request_slave_channel_reason(dev, "tx"); - if (IS_ERR(as->dma.chan_tx)) { - err = PTR_ERR(as->dma.chan_tx); + master->dma_tx = dma_request_slave_channel_reason(dev, "tx"); + if (IS_ERR(master->dma_tx)) { + err = PTR_ERR(master->dma_tx); if (err == -EPROBE_DEFER) { dev_warn(dev, "no DMA channel available at the moment\n"); - return err; + goto error_clear; } dev_err(dev, "DMA TX channel not available, SPI unable to use DMA\n"); err = -EBUSY; - goto error; + goto error_clear; } /* * No reason to check EPROBE_DEFER here since we have already requested * tx channel. If it fails here, it's for another reason. */ - as->dma.chan_rx = dma_request_slave_channel(dev, "rx"); + master->dma_rx = dma_request_slave_channel(dev, "rx"); - if (!as->dma.chan_rx) { + if (!master->dma_rx) { dev_err(dev, "DMA RX channel not available, SPI unable to use DMA\n"); err = -EBUSY; @@ -557,31 +553,38 @@ static int atmel_spi_configure_dma(struct atmel_spi *as) dev_info(&as->pdev->dev, "Using %s (tx) and %s (rx) for DMA transfers\n", - dma_chan_name(as->dma.chan_tx), - dma_chan_name(as->dma.chan_rx)); + dma_chan_name(master->dma_tx), + dma_chan_name(master->dma_rx)); + return 0; error: - if (as->dma.chan_rx) - dma_release_channel(as->dma.chan_rx); - if (!IS_ERR(as->dma.chan_tx)) - dma_release_channel(as->dma.chan_tx); + if (master->dma_rx) + dma_release_channel(master->dma_rx); + if (!IS_ERR(master->dma_tx)) + dma_release_channel(master->dma_tx); +error_clear: + master->dma_tx = master->dma_rx = NULL; return err; } -static void atmel_spi_stop_dma(struct atmel_spi *as) +static void atmel_spi_stop_dma(struct spi_master *master) { - if (as->dma.chan_rx) - dmaengine_terminate_all(as->dma.chan_rx); - if (as->dma.chan_tx) - dmaengine_terminate_all(as->dma.chan_tx); + if (master->dma_rx) + dmaengine_terminate_all(master->dma_rx); + if (master->dma_tx) + dmaengine_terminate_all(master->dma_tx); } -static void atmel_spi_release_dma(struct atmel_spi *as) +static void atmel_spi_release_dma(struct spi_master *master) { - if (as->dma.chan_rx) - dma_release_channel(as->dma.chan_rx); - if (as->dma.chan_tx) - dma_release_channel(as->dma.chan_tx); + if (master->dma_rx) { + dma_release_channel(master->dma_rx); + master->dma_rx = NULL; + } + if (master->dma_tx) { + dma_release_channel(master->dma_tx); + master->dma_tx = NULL; + } } /* This function is called by the DMA driver from tasklet context */ @@ -611,14 +614,10 @@ static void atmel_spi_next_xfer_single(struct spi_master *master, cpu_relax(); } - if (xfer->tx_buf) { - if (xfer->bits_per_word > 8) - spi_writel(as, TDR, *(u16 *)(xfer->tx_buf + xfer_pos)); - else - spi_writel(as, TDR, *(u8 *)(xfer->tx_buf + xfer_pos)); - } else { - spi_writel(as, TDR, 0); - } + if (xfer->bits_per_word > 8) + spi_writel(as, TDR, *(u16 *)(xfer->tx_buf + xfer_pos)); + else + spi_writel(as, TDR, *(u8 *)(xfer->tx_buf + xfer_pos)); dev_dbg(master->dev.parent, " start pio xfer %p: len %u tx %p rx %p bitpw %d\n", @@ -665,17 +664,12 @@ static void atmel_spi_next_xfer_fifo(struct spi_master *master, /* Fill TX FIFO */ while (num_data >= 2) { - if (xfer->tx_buf) { - if (xfer->bits_per_word > 8) { - td0 = *words++; - td1 = *words++; - } else { - td0 = *bytes++; - td1 = *bytes++; - } + if (xfer->bits_per_word > 8) { + td0 = *words++; + td1 = *words++; } else { - td0 = 0; - td1 = 0; + td0 = *bytes++; + td1 = *bytes++; } spi_writel(as, TDR, (td1 << 16) | td0); @@ -683,14 +677,10 @@ static void atmel_spi_next_xfer_fifo(struct spi_master *master, } if (num_data) { - if (xfer->tx_buf) { - if (xfer->bits_per_word > 8) - td0 = *words++; - else - td0 = *bytes++; - } else { - td0 = 0; - } + if (xfer->bits_per_word > 8) + td0 = *words++; + else + td0 = *bytes++; spi_writew(as, TDR, td0); num_data--; @@ -730,13 +720,12 @@ static int atmel_spi_next_xfer_dma_submit(struct spi_master *master, u32 *plen) { struct atmel_spi *as = spi_master_get_devdata(master); - struct dma_chan *rxchan = as->dma.chan_rx; - struct dma_chan *txchan = as->dma.chan_tx; + struct dma_chan *rxchan = master->dma_rx; + struct dma_chan *txchan = master->dma_tx; struct dma_async_tx_descriptor *rxdesc; struct dma_async_tx_descriptor *txdesc; struct dma_slave_config slave_config; dma_cookie_t cookie; - u32 len = *plen; dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_dma_submit\n"); @@ -747,44 +736,22 @@ static int atmel_spi_next_xfer_dma_submit(struct spi_master *master, /* release lock for DMA operations */ atmel_spi_unlock(as); - /* prepare the RX dma transfer */ - sg_init_table(&as->dma.sgrx, 1); - if (xfer->rx_buf) { - as->dma.sgrx.dma_address = xfer->rx_dma + xfer->len - *plen; - } else { - as->dma.sgrx.dma_address = as->buffer_dma; - if (len > BUFFER_SIZE) - len = BUFFER_SIZE; - } - - /* prepare the TX dma transfer */ - sg_init_table(&as->dma.sgtx, 1); - if (xfer->tx_buf) { - as->dma.sgtx.dma_address = xfer->tx_dma + xfer->len - *plen; - } else { - as->dma.sgtx.dma_address = as->buffer_dma; - if (len > BUFFER_SIZE) - len = BUFFER_SIZE; - memset(as->buffer, 0, len); - } - - sg_dma_len(&as->dma.sgtx) = len; - sg_dma_len(&as->dma.sgrx) = len; - - *plen = len; + *plen = xfer->len; if (atmel_spi_dma_slave_config(as, &slave_config, xfer->bits_per_word)) goto err_exit; /* Send both scatterlists */ - rxdesc = dmaengine_prep_slave_sg(rxchan, &as->dma.sgrx, 1, + rxdesc = dmaengine_prep_slave_sg(rxchan, + xfer->rx_sg.sgl, xfer->rx_sg.nents, DMA_FROM_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!rxdesc) goto err_dma; - txdesc = dmaengine_prep_slave_sg(txchan, &as->dma.sgtx, 1, + txdesc = dmaengine_prep_slave_sg(txchan, + xfer->tx_sg.sgl, xfer->tx_sg.nents, DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!txdesc) @@ -818,7 +785,7 @@ static int atmel_spi_next_xfer_dma_submit(struct spi_master *master, err_dma: spi_writel(as, IDR, SPI_BIT(OVRES)); - atmel_spi_stop_dma(as); + atmel_spi_stop_dma(master); err_exit: atmel_spi_lock(as); return -ENOMEM; @@ -830,30 +797,10 @@ static void atmel_spi_next_xfer_data(struct spi_master *master, dma_addr_t *rx_dma, u32 *plen) { - struct atmel_spi *as = spi_master_get_devdata(master); - u32 len = *plen; - - /* use scratch buffer only when rx or tx data is unspecified */ - if (xfer->rx_buf) - *rx_dma = xfer->rx_dma + xfer->len - *plen; - else { - *rx_dma = as->buffer_dma; - if (len > BUFFER_SIZE) - len = BUFFER_SIZE; - } - - if (xfer->tx_buf) - *tx_dma = xfer->tx_dma + xfer->len - *plen; - else { - *tx_dma = as->buffer_dma; - if (len > BUFFER_SIZE) - len = BUFFER_SIZE; - memset(as->buffer, 0, len); - dma_sync_single_for_device(&as->pdev->dev, - as->buffer_dma, len, DMA_TO_DEVICE); - } - - *plen = len; + *rx_dma = xfer->rx_dma + xfer->len - *plen; + *tx_dma = xfer->tx_dma + xfer->len - *plen; + if (*plen > master->max_dma_len) + *plen = master->max_dma_len; } static int atmel_spi_set_xfer_speed(struct atmel_spi *as, @@ -864,7 +811,7 @@ static int atmel_spi_set_xfer_speed(struct atmel_spi *as, unsigned long bus_hz; /* v1 chips start out at half the peripheral bus speed. */ - bus_hz = clk_get_rate(as->clk); + bus_hz = as->spi_clk; if (!atmel_spi_is_v2(as)) bus_hz /= 2; @@ -1025,16 +972,12 @@ atmel_spi_pump_single_data(struct atmel_spi *as, struct spi_transfer *xfer) u16 *rxp16; unsigned long xfer_pos = xfer->len - as->current_remaining_bytes; - if (xfer->rx_buf) { - if (xfer->bits_per_word > 8) { - rxp16 = (u16 *)(((u8 *)xfer->rx_buf) + xfer_pos); - *rxp16 = spi_readl(as, RDR); - } else { - rxp = ((u8 *)xfer->rx_buf) + xfer_pos; - *rxp = spi_readl(as, RDR); - } + if (xfer->bits_per_word > 8) { + rxp16 = (u16 *)(((u8 *)xfer->rx_buf) + xfer_pos); + *rxp16 = spi_readl(as, RDR); } else { - spi_readl(as, RDR); + rxp = ((u8 *)xfer->rx_buf) + xfer_pos; + *rxp = spi_readl(as, RDR); } if (xfer->bits_per_word > 8) { if (as->current_remaining_bytes > 2) @@ -1073,12 +1016,10 @@ atmel_spi_pump_fifo_data(struct atmel_spi *as, struct spi_transfer *xfer) /* Read data */ while (num_data) { rd = spi_readl(as, RDR); - if (xfer->rx_buf) { - if (xfer->bits_per_word > 8) - *words++ = rd; - else - *bytes++ = rd; - } + if (xfer->bits_per_word > 8) + *words++ = rd; + else + *bytes++ = rd; num_data--; } } @@ -1204,7 +1145,6 @@ static int atmel_spi_setup(struct spi_device *spi) u32 csr; unsigned int bits = spi->bits_per_word; unsigned int npcs_pin; - int ret; as = spi_master_get_devdata(spi->master); @@ -1247,16 +1187,9 @@ static int atmel_spi_setup(struct spi_device *spi) if (!asd) return -ENOMEM; - if (as->use_cs_gpios) { - ret = gpio_request(npcs_pin, dev_name(&spi->dev)); - if (ret) { - kfree(asd); - return ret; - } - + if (as->use_cs_gpios) gpio_direction_output(npcs_pin, !(spi->mode & SPI_CS_HIGH)); - } asd->npcs_pin = npcs_pin; spi->controller_state = asd; @@ -1307,7 +1240,7 @@ static int atmel_spi_one_transfer(struct spi_master *master, * better fault reporting. */ if ((!msg->is_dma_mapped) - && (atmel_spi_use_dma(as, xfer) || as->use_pdc)) { + && as->use_pdc) { if (atmel_spi_dma_map_xfer(as, xfer) < 0) return -ENOMEM; } @@ -1380,11 +1313,11 @@ static int atmel_spi_one_transfer(struct spi_master *master, spi_readl(as, SR); } else if (atmel_spi_use_dma(as, xfer)) { - atmel_spi_stop_dma(as); + atmel_spi_stop_dma(master); } if (!msg->is_dma_mapped - && (atmel_spi_use_dma(as, xfer) || as->use_pdc)) + && as->use_pdc) atmel_spi_dma_unmap_xfer(master, xfer); return 0; @@ -1395,7 +1328,7 @@ static int atmel_spi_one_transfer(struct spi_master *master, } if (!msg->is_dma_mapped - && (atmel_spi_use_dma(as, xfer) || as->use_pdc)) + && as->use_pdc) atmel_spi_dma_unmap_xfer(master, xfer); if (xfer->delay_usecs) @@ -1471,13 +1404,11 @@ msg_done: static void atmel_spi_cleanup(struct spi_device *spi) { struct atmel_spi_device *asd = spi->controller_state; - unsigned gpio = (unsigned long) spi->controller_data; if (!asd) return; spi->controller_state = NULL; - gpio_free(gpio); kfree(asd); } @@ -1499,6 +1430,39 @@ static void atmel_get_caps(struct atmel_spi *as) } /*-------------------------------------------------------------------------*/ +static int atmel_spi_gpio_cs(struct platform_device *pdev) +{ + struct spi_master *master = platform_get_drvdata(pdev); + struct atmel_spi *as = spi_master_get_devdata(master); + struct device_node *np = master->dev.of_node; + int i; + int ret = 0; + int nb = 0; + + if (!as->use_cs_gpios) + return 0; + + if (!np) + return 0; + + nb = of_gpio_named_count(np, "cs-gpios"); + for (i = 0; i < nb; i++) { + int cs_gpio = of_get_named_gpio(pdev->dev.of_node, + "cs-gpios", i); + + if (cs_gpio == -EPROBE_DEFER) + return cs_gpio; + + if (gpio_is_valid(cs_gpio)) { + ret = devm_gpio_request(&pdev->dev, cs_gpio, + dev_name(&pdev->dev)); + if (ret) + return ret; + } + } + + return 0; +} static int atmel_spi_probe(struct platform_device *pdev) { @@ -1537,29 +1501,23 @@ static int atmel_spi_probe(struct platform_device *pdev) master->bus_num = pdev->id; master->num_chipselect = master->dev.of_node ? 0 : 4; master->setup = atmel_spi_setup; + master->flags = (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX); master->transfer_one_message = atmel_spi_transfer_one_message; master->cleanup = atmel_spi_cleanup; master->auto_runtime_pm = true; + master->max_dma_len = SPI_MAX_DMA_XFER; + master->can_dma = atmel_spi_can_dma; platform_set_drvdata(pdev, master); as = spi_master_get_devdata(master); - /* - * Scratch buffer is used for throwaway rx and tx data. - * It's coherent to minimize dcache pollution. - */ - as->buffer = dma_alloc_coherent(&pdev->dev, BUFFER_SIZE, - &as->buffer_dma, GFP_KERNEL); - if (!as->buffer) - goto out_free; - spin_lock_init(&as->lock); as->pdev = pdev; as->regs = devm_ioremap_resource(&pdev->dev, regs); if (IS_ERR(as->regs)) { ret = PTR_ERR(as->regs); - goto out_free_buffer; + goto out_unmap_regs; } as->phybase = regs->start; as->irq = irq; @@ -1577,14 +1535,19 @@ static int atmel_spi_probe(struct platform_device *pdev) master->num_chipselect = 4; } + ret = atmel_spi_gpio_cs(pdev); + if (ret) + goto out_unmap_regs; + as->use_dma = false; as->use_pdc = false; if (as->caps.has_dma_support) { - ret = atmel_spi_configure_dma(as); - if (ret == 0) + ret = atmel_spi_configure_dma(master, as); + if (ret == 0) { as->use_dma = true; - else if (ret == -EPROBE_DEFER) + } else if (ret == -EPROBE_DEFER) { return ret; + } } else { as->use_pdc = true; } @@ -1606,6 +1569,9 @@ static int atmel_spi_probe(struct platform_device *pdev) ret = clk_prepare_enable(clk); if (ret) goto out_free_irq; + + as->spi_clk = clk_get_rate(clk); + spi_writel(as, CR, SPI_BIT(SWRST)); spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ if (as->caps.has_wdrbt) { @@ -1626,10 +1592,6 @@ static int atmel_spi_probe(struct platform_device *pdev) spi_writel(as, CR, SPI_BIT(FIFOEN)); } - /* go! */ - dev_info(&pdev->dev, "Atmel SPI Controller at 0x%08lx (irq %d)\n", - (unsigned long)regs->start, irq); - pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT); pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_set_active(&pdev->dev); @@ -1639,6 +1601,10 @@ static int atmel_spi_probe(struct platform_device *pdev) if (ret) goto out_free_dma; + /* go! */ + dev_info(&pdev->dev, "Atmel SPI Controller at 0x%08lx (irq %d)\n", + (unsigned long)regs->start, irq); + return 0; out_free_dma: @@ -1646,16 +1612,13 @@ out_free_dma: pm_runtime_set_suspended(&pdev->dev); if (as->use_dma) - atmel_spi_release_dma(as); + atmel_spi_release_dma(master); spi_writel(as, CR, SPI_BIT(SWRST)); spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ clk_disable_unprepare(clk); out_free_irq: out_unmap_regs: -out_free_buffer: - dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer, - as->buffer_dma); out_free: spi_master_put(master); return ret; @@ -1671,8 +1634,8 @@ static int atmel_spi_remove(struct platform_device *pdev) /* reset the hardware and block queue progress */ spin_lock_irq(&as->lock); if (as->use_dma) { - atmel_spi_stop_dma(as); - atmel_spi_release_dma(as); + atmel_spi_stop_dma(master); + atmel_spi_release_dma(master); } spi_writel(as, CR, SPI_BIT(SWRST)); @@ -1680,9 +1643,6 @@ static int atmel_spi_remove(struct platform_device *pdev) spi_readl(as, SR); spin_unlock_irq(&as->lock); - dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer, - as->buffer_dma); - clk_disable_unprepare(as->clk); pm_runtime_put_noidle(&pdev->dev); |