diff options
Diffstat (limited to 'drivers/spi/spi-orion.c')
| -rw-r--r-- | drivers/spi/spi-orion.c | 121 |
1 files changed, 97 insertions, 24 deletions
diff --git a/drivers/spi/spi-orion.c b/drivers/spi/spi-orion.c index c4675fa8b645..835cdda6f4f5 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_device.h> #include <linux/clk.h> #include <linux/sizes.h> #include <asm/unaligned.h> @@ -40,13 +41,27 @@ #define ORION_SPI_MODE_CPHA (1 << 12) #define ORION_SPI_IF_8_16_BIT_MODE (1 << 5) #define ORION_SPI_CLK_PRESCALE_MASK 0x1F +#define ARMADA_SPI_CLK_PRESCALE_MASK 0xDF #define ORION_SPI_MODE_MASK (ORION_SPI_MODE_CPOL | \ ORION_SPI_MODE_CPHA) +enum orion_spi_type { + ORION_SPI, + ARMADA_SPI, +}; + +struct orion_spi_dev { + enum orion_spi_type typ; + unsigned int min_divisor; + unsigned int max_divisor; + u32 prescale_mask; +}; + struct orion_spi { struct spi_master *master; void __iomem *base; struct clk *clk; + const struct orion_spi_dev *devdata; }; static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg) @@ -83,30 +98,66 @@ static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed) u32 prescale; u32 reg; struct orion_spi *orion_spi; + const struct orion_spi_dev *devdata; orion_spi = spi_master_get_devdata(spi->master); + devdata = orion_spi->devdata; tclk_hz = clk_get_rate(orion_spi->clk); - /* - * the supported rates are: 4,6,8...30 - * round up as we look for equal or less speed - */ - rate = DIV_ROUND_UP(tclk_hz, speed); - rate = roundup(rate, 2); + if (devdata->typ == ARMADA_SPI) { + unsigned int clk, spr, sppr, sppr2, err; + unsigned int best_spr, best_sppr, best_err; - /* check if requested speed is too small */ - if (rate > 30) - return -EINVAL; + best_err = speed; + best_spr = 0; + best_sppr = 0; - if (rate < 4) - rate = 4; + /* Iterate over the valid range looking for best fit */ + for (sppr = 0; sppr < 8; sppr++) { + sppr2 = 0x1 << sppr; + + spr = tclk_hz / sppr2; + spr = DIV_ROUND_UP(spr, speed); + if ((spr == 0) || (spr > 15)) + continue; + + clk = tclk_hz / (spr * sppr2); + err = speed - clk; + + if (err < best_err) { + best_spr = spr; + best_sppr = sppr; + best_err = err; + } + } - /* Convert the rate to SPI clock divisor value. */ - prescale = 0x10 + rate/2; + if ((best_sppr == 0) && (best_spr == 0)) + return -EINVAL; + + prescale = ((best_sppr & 0x6) << 5) | + ((best_sppr & 0x1) << 4) | best_spr; + } else { + /* + * the supported rates are: 4,6,8...30 + * round up as we look for equal or less speed + */ + rate = DIV_ROUND_UP(tclk_hz, speed); + rate = roundup(rate, 2); + + /* check if requested speed is too small */ + if (rate > 30) + return -EINVAL; + + if (rate < 4) + rate = 4; + + /* Convert the rate to SPI clock divisor value. */ + prescale = 0x10 + rate/2; + } reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG)); - reg = ((reg & ~ORION_SPI_CLK_PRESCALE_MASK) | prescale); + reg = ((reg & ~devdata->prescale_mask) | prescale); writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG)); return 0; @@ -179,8 +230,8 @@ static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi) for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) { if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG))) return 1; - else - udelay(1); + + udelay(1); } return -1; @@ -342,8 +393,31 @@ static int orion_spi_reset(struct orion_spi *orion_spi) return 0; } +static const struct orion_spi_dev orion_spi_dev_data = { + .typ = ORION_SPI, + .min_divisor = 4, + .max_divisor = 30, + .prescale_mask = ORION_SPI_CLK_PRESCALE_MASK, +}; + +static const struct orion_spi_dev armada_spi_dev_data = { + .typ = ARMADA_SPI, + .min_divisor = 1, + .max_divisor = 1920, + .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK, +}; + +static const struct of_device_id orion_spi_of_match_table[] = { + { .compatible = "marvell,orion-spi", .data = &orion_spi_dev_data, }, + { .compatible = "marvell,armada-370-spi", .data = &armada_spi_dev_data, }, + {} +}; +MODULE_DEVICE_TABLE(of, orion_spi_of_match_table); + static int orion_spi_probe(struct platform_device *pdev) { + const struct of_device_id *of_id; + const struct orion_spi_dev *devdata; struct spi_master *master; struct orion_spi *spi; struct resource *r; @@ -360,6 +434,7 @@ static int orion_spi_probe(struct platform_device *pdev) master->bus_num = pdev->id; if (pdev->dev.of_node) { u32 cell_index; + if (!of_property_read_u32(pdev->dev.of_node, "cell-index", &cell_index)) master->bus_num = cell_index; @@ -378,6 +453,10 @@ static int orion_spi_probe(struct platform_device *pdev) spi = spi_master_get_devdata(master); spi->master = master; + of_id = of_match_device(orion_spi_of_match_table, &pdev->dev); + devdata = of_id->data; + spi->devdata = devdata; + spi->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(spi->clk)) { status = PTR_ERR(spi->clk); @@ -389,8 +468,8 @@ static int orion_spi_probe(struct platform_device *pdev) goto out; tclk_hz = clk_get_rate(spi->clk); - master->max_speed_hz = DIV_ROUND_UP(tclk_hz, 4); - master->min_speed_hz = DIV_ROUND_UP(tclk_hz, 30); + master->max_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->min_divisor); + master->min_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->max_divisor); r = platform_get_resource(pdev, IORESOURCE_MEM, 0); spi->base = devm_ioremap_resource(&pdev->dev, r); @@ -469,12 +548,6 @@ static const struct dev_pm_ops orion_spi_pm_ops = { NULL) }; -static const struct of_device_id orion_spi_of_match_table[] = { - { .compatible = "marvell,orion-spi", }, - {} -}; -MODULE_DEVICE_TABLE(of, orion_spi_of_match_table); - static struct platform_driver orion_spi_driver = { .driver = { .name = DRIVER_NAME, |