diff options
Diffstat (limited to 'drivers/spi/spi-orion.c')
| -rw-r--r-- | drivers/spi/spi-orion.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/drivers/spi/spi-orion.c b/drivers/spi/spi-orion.c index a87cfd4ba17b..ded37025b445 100644 --- a/drivers/spi/spi-orion.c +++ b/drivers/spi/spi-orion.c @@ -18,6 +18,7 @@ #include <linux/module.h> #include <linux/pm_runtime.h> #include <linux/of.h> +#include <linux/of_address.h> #include <linux/of_device.h> #include <linux/clk.h> #include <linux/sizes.h> @@ -43,6 +44,9 @@ #define ORION_SPI_INT_CAUSE_REG 0x10 #define ORION_SPI_TIMING_PARAMS_REG 0x18 +/* Register for the "Direct Mode" */ +#define SPI_DIRECT_WRITE_CONFIG_REG 0x20 + #define ORION_SPI_TMISO_SAMPLE_MASK (0x3 << 6) #define ORION_SPI_TMISO_SAMPLE_1 (1 << 6) #define ORION_SPI_TMISO_SAMPLE_2 (2 << 6) @@ -78,11 +82,18 @@ struct orion_spi_dev { bool is_errata_50mhz_ac; }; +struct orion_direct_acc { + void __iomem *vaddr; + u32 size; +}; + struct orion_spi { struct spi_master *master; void __iomem *base; struct clk *clk; const struct orion_spi_dev *devdata; + + struct orion_direct_acc direct_access[ORION_NUM_CHIPSELECTS]; }; static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg) @@ -372,10 +383,39 @@ orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer) { unsigned int count; int word_len; + struct orion_spi *orion_spi; + int cs = spi->chip_select; word_len = spi->bits_per_word; count = xfer->len; + orion_spi = spi_master_get_devdata(spi->master); + + /* + * Use SPI direct write mode if base address is available. Otherwise + * fall back to PIO mode for this transfer. + */ + if ((orion_spi->direct_access[cs].vaddr) && (xfer->tx_buf) && + (word_len == 8)) { + unsigned int cnt = count / 4; + unsigned int rem = count % 4; + + /* + * Send the TX-data to the SPI device via the direct + * mapped address window + */ + iowrite32_rep(orion_spi->direct_access[cs].vaddr, + xfer->tx_buf, cnt); + if (rem) { + u32 *buf = (u32 *)xfer->tx_buf; + + iowrite8_rep(orion_spi->direct_access[cs].vaddr, + &buf[cnt], rem); + } + + return count; + } + if (word_len == 8) { const u8 *tx = xfer->tx_buf; u8 *rx = xfer->rx_buf; @@ -425,6 +465,10 @@ static int orion_spi_reset(struct orion_spi *orion_spi) { /* Verify that the CS is deasserted */ orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1); + + /* Don't deassert CS between the direct mapped SPI transfers */ + writel(0, spi_reg(orion_spi, SPI_DIRECT_WRITE_CONFIG_REG)); + return 0; } @@ -504,6 +548,7 @@ static int orion_spi_probe(struct platform_device *pdev) struct resource *r; unsigned long tclk_hz; int status = 0; + struct device_node *np; master = spi_alloc_master(&pdev->dev, sizeof(*spi)); if (master == NULL) { @@ -576,6 +621,49 @@ static int orion_spi_probe(struct platform_device *pdev) goto out_rel_clk; } + /* Scan all SPI devices of this controller for direct mapped devices */ + for_each_available_child_of_node(pdev->dev.of_node, np) { + u32 cs; + + /* Get chip-select number from the "reg" property */ + status = of_property_read_u32(np, "reg", &cs); + if (status) { + dev_err(&pdev->dev, + "%s has no valid 'reg' property (%d)\n", + np->full_name, status); + status = 0; + continue; + } + + /* + * Check if an address is configured for this SPI device. If + * not, the MBus mapping via the 'ranges' property in the 'soc' + * node is not configured and this device should not use the + * direct mode. In this case, just continue with the next + * device. + */ + status = of_address_to_resource(pdev->dev.of_node, cs + 1, r); + if (status) + continue; + + /* + * Only map one page for direct access. This is enough for the + * simple TX transfer which only writes to the first word. + * This needs to get extended for the direct SPI-NOR / SPI-NAND + * support, once this gets implemented. + */ + spi->direct_access[cs].vaddr = devm_ioremap(&pdev->dev, + r->start, + PAGE_SIZE); + if (!spi->direct_access[cs].vaddr) { + status = -ENOMEM; + goto out_rel_clk; + } + spi->direct_access[cs].size = PAGE_SIZE; + + dev_info(&pdev->dev, "CS%d configured for direct access\n", cs); + } + pm_runtime_set_active(&pdev->dev); pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT); |