diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-geni-qcom.c | 254 |
1 files changed, 239 insertions, 15 deletions
diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c index 2f51421e2a71..27a446faf143 100644 --- a/drivers/spi/spi-geni-qcom.c +++ b/drivers/spi/spi-geni-qcom.c @@ -2,6 +2,9 @@ // Copyright (c) 2017-2018, The Linux foundation. All rights reserved. #include <linux/clk.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/dma/qcom-gpi-dma.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/log2.h> @@ -63,6 +66,15 @@ #define TIMESTAMP_AFTER BIT(3) #define POST_CMD_DELAY BIT(4) +#define GSI_LOOPBACK_EN BIT(0) +#define GSI_CS_TOGGLE BIT(3) +#define GSI_CPHA BIT(4) +#define GSI_CPOL BIT(5) + +#define MAX_TX_SG 3 +#define NUM_SPI_XFER 8 +#define SPI_XFER_TIMEOUT_MS 250 + struct spi_geni_master { struct geni_se se; struct device *dev; @@ -84,6 +96,9 @@ struct spi_geni_master { int irq; bool cs_flag; bool abort_failed; + struct dma_chan *tx; + struct dma_chan *rx; + int cur_xfer_mode; }; static int get_spi_clk_cfg(unsigned int speed_hz, @@ -330,34 +345,197 @@ static int setup_fifo_params(struct spi_device *spi_slv, return geni_spi_set_clock_and_bw(mas, spi_slv->max_speed_hz); } +static void +spi_gsi_callback_result(void *cb, const struct dmaengine_result *result) +{ + struct spi_master *spi = cb; + + if (result->result != DMA_TRANS_NOERROR) { + dev_err(&spi->dev, "DMA txn failed: %d\n", result->result); + return; + } + + if (!result->residue) { + dev_dbg(&spi->dev, "DMA txn completed\n"); + spi_finalize_current_transfer(spi); + } else { + dev_err(&spi->dev, "DMA xfer has pending: %d\n", result->residue); + } +} + +static int setup_gsi_xfer(struct spi_transfer *xfer, struct spi_geni_master *mas, + struct spi_device *spi_slv, struct spi_master *spi) +{ + unsigned long flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK; + struct dma_slave_config config = {}; + struct gpi_spi_config peripheral = {}; + struct dma_async_tx_descriptor *tx_desc, *rx_desc; + int ret; + + config.peripheral_config = &peripheral; + config.peripheral_size = sizeof(peripheral); + peripheral.set_config = true; + + if (xfer->bits_per_word != mas->cur_bits_per_word || + xfer->speed_hz != mas->cur_speed_hz) { + mas->cur_bits_per_word = xfer->bits_per_word; + mas->cur_speed_hz = xfer->speed_hz; + } + + if (xfer->tx_buf && xfer->rx_buf) { + peripheral.cmd = SPI_DUPLEX; + } else if (xfer->tx_buf) { + peripheral.cmd = SPI_TX; + peripheral.rx_len = 0; + } else if (xfer->rx_buf) { + peripheral.cmd = SPI_RX; + if (!(mas->cur_bits_per_word % MIN_WORD_LEN)) { + peripheral.rx_len = ((xfer->len << 3) / mas->cur_bits_per_word); + } else { + int bytes_per_word = (mas->cur_bits_per_word / BITS_PER_BYTE) + 1; + + peripheral.rx_len = (xfer->len / bytes_per_word); + } + } + + peripheral.loopback_en = !!(spi_slv->mode & SPI_LOOP); + peripheral.clock_pol_high = !!(spi_slv->mode & SPI_CPOL); + peripheral.data_pol_high = !!(spi_slv->mode & SPI_CPHA); + peripheral.cs = spi_slv->chip_select; + peripheral.pack_en = true; + peripheral.word_len = xfer->bits_per_word - MIN_WORD_LEN; + + ret = get_spi_clk_cfg(mas->cur_speed_hz, mas, + &peripheral.clk_src, &peripheral.clk_div); + if (ret) { + dev_err(mas->dev, "Err in get_spi_clk_cfg() :%d\n", ret); + return ret; + } + + if (!xfer->cs_change) { + if (!list_is_last(&xfer->transfer_list, &spi->cur_msg->transfers)) + peripheral.fragmentation = FRAGMENTATION; + } + + if (peripheral.cmd & SPI_RX) { + dmaengine_slave_config(mas->rx, &config); + rx_desc = dmaengine_prep_slave_sg(mas->rx, xfer->rx_sg.sgl, xfer->rx_sg.nents, + DMA_DEV_TO_MEM, flags); + if (!rx_desc) { + dev_err(mas->dev, "Err setting up rx desc\n"); + return -EIO; + } + } + + /* + * Prepare the TX always, even for RX or tx_buf being null, we would + * need TX to be prepared per GSI spec + */ + dmaengine_slave_config(mas->tx, &config); + tx_desc = dmaengine_prep_slave_sg(mas->tx, xfer->tx_sg.sgl, xfer->tx_sg.nents, + DMA_MEM_TO_DEV, flags); + if (!tx_desc) { + dev_err(mas->dev, "Err setting up tx desc\n"); + return -EIO; + } + + tx_desc->callback_result = spi_gsi_callback_result; + tx_desc->callback_param = spi; + + if (peripheral.cmd & SPI_RX) + dmaengine_submit(rx_desc); + dmaengine_submit(tx_desc); + + if (peripheral.cmd & SPI_RX) + dma_async_issue_pending(mas->rx); + + dma_async_issue_pending(mas->tx); + return 1; +} + +static bool geni_can_dma(struct spi_controller *ctlr, + struct spi_device *slv, struct spi_transfer *xfer) +{ + struct spi_geni_master *mas = spi_master_get_devdata(slv->master); + + /* check if dma is supported */ + return mas->cur_xfer_mode != GENI_SE_FIFO; +} + static int spi_geni_prepare_message(struct spi_master *spi, struct spi_message *spi_msg) { - int ret; struct spi_geni_master *mas = spi_master_get_devdata(spi); + int ret; - if (spi_geni_is_abort_still_pending(mas)) - return -EBUSY; + switch (mas->cur_xfer_mode) { + case GENI_SE_FIFO: + if (spi_geni_is_abort_still_pending(mas)) + return -EBUSY; + ret = setup_fifo_params(spi_msg->spi, spi); + if (ret) + dev_err(mas->dev, "Couldn't select mode %d\n", ret); + return ret; - ret = setup_fifo_params(spi_msg->spi, spi); - if (ret) - dev_err(mas->dev, "Couldn't select mode %d\n", ret); + case GENI_GPI_DMA: + /* nothing to do for GPI DMA */ + return 0; + } + + dev_err(mas->dev, "Mode not supported %d", mas->cur_xfer_mode); + return -EINVAL; +} + +static int spi_geni_grab_gpi_chan(struct spi_geni_master *mas) +{ + int ret; + + mas->tx = dma_request_chan(mas->dev, "tx"); + ret = dev_err_probe(mas->dev, IS_ERR(mas->tx), "Failed to get tx DMA ch\n"); + if (ret < 0) + goto err_tx; + + mas->rx = dma_request_chan(mas->dev, "rx"); + ret = dev_err_probe(mas->dev, IS_ERR(mas->rx), "Failed to get rx DMA ch\n"); + if (ret < 0) + goto err_rx; + + return 0; + +err_rx: + dma_release_channel(mas->tx); + mas->tx = NULL; +err_tx: + mas->rx = NULL; return ret; } +static void spi_geni_release_dma_chan(struct spi_geni_master *mas) +{ + if (mas->rx) { + dma_release_channel(mas->rx); + mas->rx = NULL; + } + + if (mas->tx) { + dma_release_channel(mas->tx); + mas->tx = NULL; + } +} + static int spi_geni_init(struct spi_geni_master *mas) { struct geni_se *se = &mas->se; unsigned int proto, major, minor, ver; - u32 spi_tx_cfg; + u32 spi_tx_cfg, fifo_disable; + int ret = -ENXIO; pm_runtime_get_sync(mas->dev); proto = geni_se_read_proto(se); if (proto != GENI_SE_SPI) { dev_err(mas->dev, "Invalid proto %d\n", proto); - pm_runtime_put(mas->dev); - return -ENXIO; + goto out_pm; } mas->tx_fifo_depth = geni_se_get_tx_fifo_depth(se); @@ -380,15 +558,38 @@ static int spi_geni_init(struct spi_geni_master *mas) else mas->oversampling = 1; - geni_se_select_mode(se, GENI_SE_FIFO); + fifo_disable = readl(se->base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE; + switch (fifo_disable) { + case 1: + ret = spi_geni_grab_gpi_chan(mas); + if (!ret) { /* success case */ + mas->cur_xfer_mode = GENI_GPI_DMA; + geni_se_select_mode(se, GENI_GPI_DMA); + dev_dbg(mas->dev, "Using GPI DMA mode for SPI\n"); + break; + } + /* + * in case of failure to get dma channel, we can still do the + * FIFO mode, so fallthrough + */ + dev_warn(mas->dev, "FIFO mode disabled, but couldn't get DMA, fall back to FIFO mode\n"); + fallthrough; + + case 0: + mas->cur_xfer_mode = GENI_SE_FIFO; + geni_se_select_mode(se, GENI_SE_FIFO); + ret = 0; + break; + } /* We always control CS manually */ spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG); spi_tx_cfg &= ~CS_TOGGLE; writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG); +out_pm: pm_runtime_put(mas->dev); - return 0; + return ret; } static unsigned int geni_byte_per_fifo_word(struct spi_geni_master *mas) @@ -569,8 +770,11 @@ static int spi_geni_transfer_one(struct spi_master *spi, if (!xfer->len) return 0; - setup_fifo_xfer(xfer, mas, slv->mode, spi); - return 1; + if (mas->cur_xfer_mode == GENI_SE_FIFO) { + setup_fifo_xfer(xfer, mas, slv->mode, spi); + return 1; + } + return setup_gsi_xfer(xfer, mas, slv, spi); } static irqreturn_t geni_spi_isr(int irq, void *data) @@ -665,6 +869,13 @@ static int spi_geni_probe(struct platform_device *pdev) if (irq < 0) return irq; + ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64)); + if (ret) { + ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32)); + if (ret) + return dev_err_probe(dev, ret, "could not set DMA mask\n"); + } + base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(base)) return PTR_ERR(base); @@ -704,9 +915,10 @@ static int spi_geni_probe(struct platform_device *pdev) spi->max_speed_hz = 50000000; spi->prepare_message = spi_geni_prepare_message; spi->transfer_one = spi_geni_transfer_one; + spi->can_dma = geni_can_dma; + spi->dma_map_dev = dev->parent; spi->auto_runtime_pm = true; spi->handle_err = handle_fifo_timeout; - spi->set_cs = spi_geni_set_cs; spi->use_gpio_descriptors = true; init_completion(&mas->cs_done); @@ -732,9 +944,17 @@ static int spi_geni_probe(struct platform_device *pdev) if (ret) goto spi_geni_probe_runtime_disable; + /* + * check the mode supported and set_cs for fifo mode only + * for dma (gsi) mode, the gsi will set cs based on params passed in + * TRE + */ + if (mas->cur_xfer_mode == GENI_SE_FIFO) + spi->set_cs = spi_geni_set_cs; + ret = request_irq(mas->irq, geni_spi_isr, 0, dev_name(dev), spi); if (ret) - goto spi_geni_probe_runtime_disable; + goto spi_geni_release_dma; ret = spi_register_master(spi); if (ret) @@ -743,6 +963,8 @@ static int spi_geni_probe(struct platform_device *pdev) return 0; spi_geni_probe_free_irq: free_irq(mas->irq, spi); +spi_geni_release_dma: + spi_geni_release_dma_chan(mas); spi_geni_probe_runtime_disable: pm_runtime_disable(dev); return ret; @@ -756,6 +978,8 @@ static int spi_geni_remove(struct platform_device *pdev) /* Unregister _before_ disabling pm_runtime() so we stop transfers */ spi_unregister_master(spi); + spi_geni_release_dma_chan(mas); + free_irq(mas->irq, spi); pm_runtime_disable(&pdev->dev); return 0; |