/* * Marvell Orion SPI controller driver * * Author: Shadi Ammouri * Copyright (C) 2007-2008 Marvell Ltd. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #define DRIVER_NAME "orion_spi" /* Runtime PM autosuspend timeout: PM is fairly light on this driver */ #define SPI_AUTOSUSPEND_TIMEOUT 200 /* Some SoCs using this driver support up to 8 chip selects. * It is up to the implementer to only use the chip selects * that are available. */ #define ORION_NUM_CHIPSELECTS 8 #define ORION_SPI_WAIT_RDY_MAX_LOOP 2000 /* in usec */ #define ORION_SPI_IF_CTRL_REG 0x00 #define ORION_SPI_IF_CONFIG_REG 0x04 #define ORION_SPI_DATA_OUT_REG 0x08 #define ORION_SPI_DATA_IN_REG 0x0c #define ORION_SPI_INT_CAUSE_REG 0x10 #define ORION_SPI_TIMING_PARAMS_REG 0x18 #define ORION_SPI_TMISO_SAMPLE_MASK (0x3 << 6) #define ORION_SPI_TMISO_SAMPLE_1 (1 << 6) #define ORION_SPI_TMISO_SAMPLE_2 (2 << 6) #define ORION_SPI_MODE_CPOL (1 << 11) #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) #define ORION_SPI_CS_MASK 0x1C #define ORION_SPI_CS_SHIFT 2 #define ORION_SPI_CS(cs) ((cs << ORION_SPI_CS_SHIFT) & \ ORION_SPI_CS_MASK) enum orion_spi_type { ORION_SPI, ARMADA_SPI, }; struct orion_spi_dev { enum orion_spi_type typ; /* * min_divisor and max_hz should be exclusive, the only we can * have both is for managing the armada-370-spi case with old * device tree */ unsigned long max_hz; unsigned int min_divisor; unsigned int max_divisor; u32 prescale_mask; bool is_errata_50mhz_ac; }; 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) { return orion_spi->base + reg; } static inline void orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask) { void __iomem *reg_addr = spi_reg(orion_spi, reg); u32 val; val = readl(reg_addr); val |= mask; writel(val, reg_addr); } static inline void orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask) { void __iomem *reg_addr = spi_reg(orion_spi, reg); u32 val; val = readl(reg_addr); val &= ~mask; writel(val, reg_addr); } static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed) { u32 tclk_hz; u32 rate; 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); if (devdata->typ == ARMADA_SPI) { /* * Given the core_clk (tclk_hz) and the target rate (speed) we * determine the best values for SPR (in [0 .. 15]) and SPPR (in * [0..7]) such that * * core_clk / (SPR * 2 ** SPPR) * * is as big as possible but not bigger than speed. */ /* best integer divider: */ unsigned divider = DIV_ROUND_UP(tclk_hz, speed); unsigned spr, sppr; if (divider < 16) { /* This is the easy case, divider is less than 16 */ spr = divider; sppr = 0; } else { unsigned two_pow_sppr; /* * Find the highest bit set in divider. This and the * three next bits define SPR (apart from rounding). * SPPR is then the number of zero bits that must be * appended: */ sppr = fls(divider) - 4; /* * As SPR only has 4 bits, we have to round divider up * to the next multiple of 2 ** sppr. */ two_pow_sppr = 1 << sppr; divider = (divider + two_pow_sppr - 1) & -two_pow_sppr; /* * recalculate sppr as rounding up divider might have * increased it enough to change the position of the * highest set bit. In this case the bit that now * doesn't make it into SPR is 0, so there is no need to * round again. */ sppr = fls(divider) - 4; spr = divider >> sppr; /* * Now do range checking. SPR is constructed to have a * width of 4 bits, so this is fine for sure. So we * still need to check for sppr to fit into 3 bits: */ if (sppr > 7) return -EINVAL; } prescale = ((sppr & 0x6) << 5) | ((sppr & 0x1) << 4) | 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 & ~devdata->prescale_mask) | prescale); writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG)); return 0; } static void orion_spi_mode_set(struct spi_device *spi) { u32 reg; struct orion_spi *orion_spi; orion_spi = spi_master_get_devdata(spi->master); reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG)); reg &= ~ORION_SPI_MODE_MASK; if (spi->mode & SPI_CPOL) reg |= ORION_SPI_MODE_CPOL; if (spi->mode & SPI_CPHA) reg |= ORION_SPI_MODE_CPHA; writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG)); } static void orion_spi_50mhz_ac_timing_erratum(struct spi_device *spi, unsigned int speed) { u32 reg; struct orion_spi *orion_spi; orion_spi = spi_master_get_devdata(spi->master); /* * Erratum description: (Erratum NO. FE-9144572) The device * SPI interface supports frequencies of up to 50 MHz. * However, due to this erratum, when the device core clock is * 250 MHz and the SPI interfaces is configured for 50MHz SPI * clock and CPOL=CPHA=1 there might occur data corruption on * reads from the SPI device. * Erratum Workaround: * Work in one of the following configurations: * 1. Set CPOL=CPHA=0 in "SPI Interface Configuration * Register". * 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1 * Register" before setting the interface. */ reg = readl(spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG)); reg &= ~ORION_SPI_TMISO_SAMPLE_MASK; if (clk_get_rate(orion_spi->clk) == 250000000 && speed == 50000000 && spi->mode & SPI_CPOL && spi->mode & SPI_CPHA) reg |= ORION_SPI_TMISO_SAMPLE_2; else reg |= ORION_SPI_TMISO_SAMPLE_1; /* This is the default value */ writel(reg, spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG)); } /* * called only when no transfer is active on the bus */ static int orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) { struct orion_spi *orion_spi; unsigned int speed = spi->max_speed_hz; unsigned int bits_per_word = spi->bits_per_word; int rc; orion_spi = spi_master_get_devdata(spi->master); if ((t != NULL) && t->speed_hz) speed = t->speed_hz; if ((t != NULL) && t->bits_per_word) bits_per_word = t->bits_per_word; orion_spi_mode_set(spi); if (orion_spi->devdata->is_errata_50mhz_ac) orion_spi_50mhz_ac_timing_erratum(spi, speed); rc = orion_spi_baudrate_set(spi, speed); if (rc) return rc; if (bits_per_word == 16) orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG, ORION_SPI_IF_8_16_BIT_MODE); else orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG, ORION_SPI_IF_8_16_BIT_MODE); return 0; } static void orion_spi_set_cs(struct spi_device *spi, bool enable) { struct orion_spi *orion_spi; orion_spi = spi_master_get_devdata(spi->master); orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, ORION_SPI_CS_MASK); orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, ORION_SPI_CS(spi->chip_select)); /* Chip select logic is inverted from spi_set_cs */ if (!enable) orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1); else orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1); } static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi) { int i; for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) { if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG))) return 1; udelay(1); } return -1; } static inline int orion_spi_write_read_8bit(struct spi_device *spi, const u8 **tx_buf, u8 **rx_buf) { void __iomem *tx_reg, *rx_reg, *int_reg; struct orion_spi *orion_spi; orion_spi = spi_master_get_devdata(spi->master); tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG); rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG); int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG); /* clear the interrupt cause register */ writel(0x0, int_reg); if (tx_buf && *tx_buf) writel(*(*tx_buf)++, tx_reg); else writel(0, tx_reg); if (orion_spi_wait_till_ready(orion_spi) < 0) { dev_err(&spi->dev, "TXS timed out\n"); return -1; } if (rx_buf && *rx_buf) *(*rx_buf)++ = readl(rx_reg); return 1; } static inline int orion_spi_write_read_16bit(struct spi_device *spi, const u16 **tx_buf, u16 **rx_buf) { void __iomem *tx_reg, *rx_reg, *int_reg; struct orion_spi *orion_spi; orion_spi = spi_master_get_devdata(spi->master); tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG); rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG); int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG); /* clear the interrupt cause register */ writel(0x0, int_reg); if (tx_buf && *tx_buf) writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg); else writel(0, tx_reg); if (orion_spi_wait_till_ready(orion_spi) < 0) { dev_err(&spi->dev, "TXS timed out\n"); return -1; } if (rx_buf && *rx_buf) put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++); return 1; } static unsigned int orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer) { unsigned int count; int word_len; word_len = spi->bits_per_word; count = xfer->len; if (word_len == 8) { const u8 *tx = xfer->tx_buf; u8 *rx = xfer->rx_buf; do { if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0) goto out; count--; } while (count); } else if (word_len == 16) { const u16 *tx = xfer->tx_buf; u16 *rx = xfer->rx_buf; do { if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0) goto out; count -= 2; } while (count); } out: return xfer->len - count; } static int orion_spi_transfer_one(struct spi_master *master, struct spi_device *spi, struct spi_transfer *t) { int status = 0; status = orion_spi_setup_transfer(spi, t); if (status < 0) return status; if (t->len) orion_spi_write_read(spi, t); return status; } static int orion_spi_setup(struct spi_device *spi) { return orion_spi_setup_transfer(spi, NULL); } 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); 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_370_spi_dev_data = { .typ = ARMADA_SPI, .min_divisor = 4, .max_divisor = 1920, .max_hz = 50000000, .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK, }; static const struct orion_spi_dev armada_xp_spi_dev_data = { .typ = ARMADA_SPI, .max_hz = 50000000, .max_divisor = 1920, .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK, }; static const struct orion_spi_dev armada_375_spi_dev_data = { .typ = ARMADA_SPI, .min_divisor = 15, .max_divisor = 1920, .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK, }; static const struct orion_spi_dev armada_380_spi_dev_data = { .typ = ARMADA_SPI, .max_hz = 50000000, .max_divisor = 1920, .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK, .is_errata_50mhz_ac = true, }; 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_370_spi_dev_data, }, { .compatible = "marvell,armada-375-spi", .data = &armada_375_spi_dev_data, }, { .compatible = "marvell,armada-380-spi", .data = &armada_380_spi_dev_data, }, { .compatible = "marvell,armada-390-spi", .data = &armada_xp_spi_dev_data, }, { .compatible = "marvell,armada-xp-spi", .data = &armada_xp_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; unsigned long tclk_hz; int status = 0; master = spi_alloc_master(&pdev->dev, sizeof(*spi)); if (master == NULL) { dev_dbg(&pdev->dev, "master allocation failed\n"); return -ENOMEM; } if (pdev->id != -1) 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; } /* we support only mode 0, and no options */ master->mode_bits = SPI_CPHA | SPI_CPOL; master->set_cs = orion_spi_set_cs; master->transfer_one = orion_spi_transfer_one; master->num_chipselect = ORION_NUM_CHIPSELECTS; master->setup = orion_spi_setup; master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16); master->auto_runtime_pm = true; platform_set_drvdata(pdev, master); spi = spi_master_get_devdata(master); spi->master = master; of_id = of_match_device(orion_spi_of_match_table, &pdev->dev); devdata = (of_id) ? of_id->data : &orion_spi_dev_data; spi->devdata = devdata; spi->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(spi->clk)) { status = PTR_ERR(spi->clk); goto out; } status = clk_prepare_enable(spi->clk); if (status) goto out; tclk_hz = clk_get_rate(spi->clk); /* * With old device tree, armada-370-spi could be used with * Armada XP, however for this SoC the maximum frequency is * 50MHz instead of tclk/4. On Armada 370, tclk cannot be * higher than 200MHz. So, in order to be able to handle both * SoCs, we can take the minimum of 50MHz and tclk/4. */ if (of_device_is_compatible(pdev->dev.of_node, "marvell,armada-370-spi")) master->max_speed_hz = min(devdata->max_hz, DIV_ROUND_UP(tclk_hz, devdata->min_divisor)); else if (devdata->min_divisor) master->max_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->min_divisor); else master->max_speed_hz = devdata->max_hz; 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); if (IS_ERR(spi->base)) { status = PTR_ERR(spi->base); goto out_rel_clk; } pm_runtime_set_active(&pdev->dev); pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT); pm_runtime_enable(&pdev->dev); status = orion_spi_reset(spi); if (status < 0) goto out_rel_pm; pm_runtime_mark_last_busy(&pdev->dev); pm_runtime_put_autosuspend(&pdev->dev); master->dev.of_node = pdev->dev.of_node; status = spi_register_master(master); if (status < 0) goto out_rel_pm; return status; out_rel_pm: pm_runtime_disable(&pdev->dev); out_rel_clk: clk_disable_unprepare(spi->clk); out: spi_master_put(master); return status; } static int orion_spi_remove(struct platform_device *pdev) { struct spi_master *master = platform_get_drvdata(pdev); struct orion_spi *spi = spi_master_get_devdata(master); pm_runtime_get_sync(&pdev->dev); clk_disable_unprepare(spi->clk); spi_unregister_master(master); pm_runtime_disable(&pdev->dev); return 0; } MODULE_ALIAS("platform:" DRIVER_NAME); #ifdef CONFIG_PM static int orion_spi_runtime_suspend(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); struct orion_spi *spi = spi_master_get_devdata(master); clk_disable_unprepare(spi->clk); return 0; } static int orion_spi_runtime_resume(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); struct orion_spi *spi = spi_master_get_devdata(master); return clk_prepare_enable(spi->clk); } #endif static const struct dev_pm_ops orion_spi_pm_ops = { SET_RUNTIME_PM_OPS(orion_spi_runtime_suspend, orion_spi_runtime_resume, NULL) }; static struct platform_driver orion_spi_driver = { .driver = { .name = DRIVER_NAME, .pm = &orion_spi_pm_ops, .of_match_table = of_match_ptr(orion_spi_of_match_table), }, .probe = orion_spi_probe, .remove = orion_spi_remove, }; module_platform_driver(orion_spi_driver); MODULE_DESCRIPTION("Orion SPI driver"); MODULE_AUTHOR("Shadi Ammouri "); MODULE_LICENSE("GPL");