/* * Broadcom BCM63XX High Speed SPI Controller driver * * Copyright 2000-2010 Broadcom Corporation * Copyright 2012-2013 Jonas Gorski <jogo@openwrt.org> * * Licensed under the GNU/GPL. See COPYING for details. */ #include <linux/kernel.h> #include <linux/init.h> #include <linux/io.h> #include <linux/clk.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/delay.h> #include <linux/dma-mapping.h> #include <linux/err.h> #include <linux/interrupt.h> #include <linux/spi/spi.h> #include <linux/mutex.h> #include <linux/of.h> #define HSSPI_GLOBAL_CTRL_REG 0x0 #define GLOBAL_CTRL_CS_POLARITY_SHIFT 0 #define GLOBAL_CTRL_CS_POLARITY_MASK 0x000000ff #define GLOBAL_CTRL_PLL_CLK_CTRL_SHIFT 8 #define GLOBAL_CTRL_PLL_CLK_CTRL_MASK 0x0000ff00 #define GLOBAL_CTRL_CLK_GATE_SSOFF BIT(16) #define GLOBAL_CTRL_CLK_POLARITY BIT(17) #define GLOBAL_CTRL_MOSI_IDLE BIT(18) #define HSSPI_GLOBAL_EXT_TRIGGER_REG 0x4 #define HSSPI_INT_STATUS_REG 0x8 #define HSSPI_INT_STATUS_MASKED_REG 0xc #define HSSPI_INT_MASK_REG 0x10 #define HSSPI_PINGx_CMD_DONE(i) BIT((i * 8) + 0) #define HSSPI_PINGx_RX_OVER(i) BIT((i * 8) + 1) #define HSSPI_PINGx_TX_UNDER(i) BIT((i * 8) + 2) #define HSSPI_PINGx_POLL_TIMEOUT(i) BIT((i * 8) + 3) #define HSSPI_PINGx_CTRL_INVAL(i) BIT((i * 8) + 4) #define HSSPI_INT_CLEAR_ALL 0xff001f1f #define HSSPI_PINGPONG_COMMAND_REG(x) (0x80 + (x) * 0x40) #define PINGPONG_CMD_COMMAND_MASK 0xf #define PINGPONG_COMMAND_NOOP 0 #define PINGPONG_COMMAND_START_NOW 1 #define PINGPONG_COMMAND_START_TRIGGER 2 #define PINGPONG_COMMAND_HALT 3 #define PINGPONG_COMMAND_FLUSH 4 #define PINGPONG_CMD_PROFILE_SHIFT 8 #define PINGPONG_CMD_SS_SHIFT 12 #define HSSPI_PINGPONG_STATUS_REG(x) (0x84 + (x) * 0x40) #define HSSPI_PROFILE_CLK_CTRL_REG(x) (0x100 + (x) * 0x20) #define CLK_CTRL_FREQ_CTRL_MASK 0x0000ffff #define CLK_CTRL_SPI_CLK_2X_SEL BIT(14) #define CLK_CTRL_ACCUM_RST_ON_LOOP BIT(15) #define HSSPI_PROFILE_SIGNAL_CTRL_REG(x) (0x104 + (x) * 0x20) #define SIGNAL_CTRL_LATCH_RISING BIT(12) #define SIGNAL_CTRL_LAUNCH_RISING BIT(13) #define SIGNAL_CTRL_ASYNC_INPUT_PATH BIT(16) #define HSSPI_PROFILE_MODE_CTRL_REG(x) (0x108 + (x) * 0x20) #define MODE_CTRL_MULTIDATA_RD_STRT_SHIFT 8 #define MODE_CTRL_MULTIDATA_WR_STRT_SHIFT 12 #define MODE_CTRL_MULTIDATA_RD_SIZE_SHIFT 16 #define MODE_CTRL_MULTIDATA_WR_SIZE_SHIFT 18 #define MODE_CTRL_MODE_3WIRE BIT(20) #define MODE_CTRL_PREPENDBYTE_CNT_SHIFT 24 #define HSSPI_FIFO_REG(x) (0x200 + (x) * 0x200) #define HSSPI_OP_MULTIBIT BIT(11) #define HSSPI_OP_CODE_SHIFT 13 #define HSSPI_OP_SLEEP (0 << HSSPI_OP_CODE_SHIFT) #define HSSPI_OP_READ_WRITE (1 << HSSPI_OP_CODE_SHIFT) #define HSSPI_OP_WRITE (2 << HSSPI_OP_CODE_SHIFT) #define HSSPI_OP_READ (3 << HSSPI_OP_CODE_SHIFT) #define HSSPI_OP_SETIRQ (4 << HSSPI_OP_CODE_SHIFT) #define HSSPI_BUFFER_LEN 512 #define HSSPI_OPCODE_LEN 2 #define HSSPI_MAX_PREPEND_LEN 15 #define HSSPI_MAX_SYNC_CLOCK 30000000 #define HSSPI_SPI_MAX_CS 8 #define HSSPI_BUS_NUM 1 /* 0 is legacy SPI */ struct bcm63xx_hsspi { struct completion done; struct mutex bus_mutex; struct platform_device *pdev; struct clk *clk; void __iomem *regs; u8 __iomem *fifo; u32 speed_hz; u8 cs_polarity; }; static void bcm63xx_hsspi_set_cs(struct bcm63xx_hsspi *bs, unsigned int cs, bool active) { u32 reg; mutex_lock(&bs->bus_mutex); reg = __raw_readl(bs->regs + HSSPI_GLOBAL_CTRL_REG); reg &= ~BIT(cs); if (active == !(bs->cs_polarity & BIT(cs))) reg |= BIT(cs); __raw_writel(reg, bs->regs + HSSPI_GLOBAL_CTRL_REG); mutex_unlock(&bs->bus_mutex); } static void bcm63xx_hsspi_set_clk(struct bcm63xx_hsspi *bs, struct spi_device *spi, int hz) { unsigned int profile = spi->chip_select; u32 reg; reg = DIV_ROUND_UP(2048, DIV_ROUND_UP(bs->speed_hz, hz)); __raw_writel(CLK_CTRL_ACCUM_RST_ON_LOOP | reg, bs->regs + HSSPI_PROFILE_CLK_CTRL_REG(profile)); reg = __raw_readl(bs->regs + HSSPI_PROFILE_SIGNAL_CTRL_REG(profile)); if (hz > HSSPI_MAX_SYNC_CLOCK) reg |= SIGNAL_CTRL_ASYNC_INPUT_PATH; else reg &= ~SIGNAL_CTRL_ASYNC_INPUT_PATH; __raw_writel(reg, bs->regs + HSSPI_PROFILE_SIGNAL_CTRL_REG(profile)); mutex_lock(&bs->bus_mutex); /* setup clock polarity */ reg = __raw_readl(bs->regs + HSSPI_GLOBAL_CTRL_REG); reg &= ~GLOBAL_CTRL_CLK_POLARITY; if (spi->mode & SPI_CPOL) reg |= GLOBAL_CTRL_CLK_POLARITY; __raw_writel(reg, bs->regs + HSSPI_GLOBAL_CTRL_REG); mutex_unlock(&bs->bus_mutex); } static int bcm63xx_hsspi_do_txrx(struct spi_device *spi, struct spi_transfer *t) { struct bcm63xx_hsspi *bs = spi_master_get_devdata(spi->master); unsigned int chip_select = spi->chip_select; u16 opcode = 0; int pending = t->len; int step_size = HSSPI_BUFFER_LEN; const u8 *tx = t->tx_buf; u8 *rx = t->rx_buf; bcm63xx_hsspi_set_clk(bs, spi, t->speed_hz); bcm63xx_hsspi_set_cs(bs, spi->chip_select, true); if (tx && rx) opcode = HSSPI_OP_READ_WRITE; else if (tx) opcode = HSSPI_OP_WRITE; else if (rx) opcode = HSSPI_OP_READ; if (opcode != HSSPI_OP_READ) step_size -= HSSPI_OPCODE_LEN; if ((opcode == HSSPI_OP_READ && t->rx_nbits == SPI_NBITS_DUAL) || (opcode == HSSPI_OP_WRITE && t->tx_nbits == SPI_NBITS_DUAL)) opcode |= HSSPI_OP_MULTIBIT; __raw_writel(1 << MODE_CTRL_MULTIDATA_WR_SIZE_SHIFT | 1 << MODE_CTRL_MULTIDATA_RD_SIZE_SHIFT | 0xff, bs->regs + HSSPI_PROFILE_MODE_CTRL_REG(chip_select)); while (pending > 0) { int curr_step = min_t(int, step_size, pending); reinit_completion(&bs->done); if (tx) { memcpy_toio(bs->fifo + HSSPI_OPCODE_LEN, tx, curr_step); tx += curr_step; } __raw_writew(opcode | curr_step, bs->fifo); /* enable interrupt */ __raw_writel(HSSPI_PINGx_CMD_DONE(0), bs->regs + HSSPI_INT_MASK_REG); /* start the transfer */ __raw_writel(!chip_select << PINGPONG_CMD_SS_SHIFT | chip_select << PINGPONG_CMD_PROFILE_SHIFT | PINGPONG_COMMAND_START_NOW, bs->regs + HSSPI_PINGPONG_COMMAND_REG(0)); if (wait_for_completion_timeout(&bs->done, HZ) == 0) { dev_err(&bs->pdev->dev, "transfer timed out!\n"); return -ETIMEDOUT; } if (rx) { memcpy_fromio(rx, bs->fifo, curr_step); rx += curr_step; } pending -= curr_step; } return 0; } static int bcm63xx_hsspi_setup(struct spi_device *spi) { struct bcm63xx_hsspi *bs = spi_master_get_devdata(spi->master); u32 reg; reg = __raw_readl(bs->regs + HSSPI_PROFILE_SIGNAL_CTRL_REG(spi->chip_select)); reg &= ~(SIGNAL_CTRL_LAUNCH_RISING | SIGNAL_CTRL_LATCH_RISING); if (spi->mode & SPI_CPHA) reg |= SIGNAL_CTRL_LAUNCH_RISING; else reg |= SIGNAL_CTRL_LATCH_RISING; __raw_writel(reg, bs->regs + HSSPI_PROFILE_SIGNAL_CTRL_REG(spi->chip_select)); mutex_lock(&bs->bus_mutex); reg = __raw_readl(bs->regs + HSSPI_GLOBAL_CTRL_REG); /* only change actual polarities if there is no transfer */ if ((reg & GLOBAL_CTRL_CS_POLARITY_MASK) == bs->cs_polarity) { if (spi->mode & SPI_CS_HIGH) reg |= BIT(spi->chip_select); else reg &= ~BIT(spi->chip_select); __raw_writel(reg, bs->regs + HSSPI_GLOBAL_CTRL_REG); } if (spi->mode & SPI_CS_HIGH) bs->cs_polarity |= BIT(spi->chip_select); else bs->cs_polarity &= ~BIT(spi->chip_select); mutex_unlock(&bs->bus_mutex); return 0; } static int bcm63xx_hsspi_transfer_one(struct spi_master *master, struct spi_message *msg) { struct bcm63xx_hsspi *bs = spi_master_get_devdata(master); struct spi_transfer *t; struct spi_device *spi = msg->spi; int status = -EINVAL; int dummy_cs; u32 reg; /* This controller does not support keeping CS active during idle. * To work around this, we use the following ugly hack: * * a. Invert the target chip select's polarity so it will be active. * b. Select a "dummy" chip select to use as the hardware target. * c. Invert the dummy chip select's polarity so it will be inactive * during the actual transfers. * d. Tell the hardware to send to the dummy chip select. Thanks to * the multiplexed nature of SPI the actual target will receive * the transfer and we see its response. * * e. At the end restore the polarities again to their default values. */ dummy_cs = !spi->chip_select; bcm63xx_hsspi_set_cs(bs, dummy_cs, true); list_for_each_entry(t, &msg->transfers, transfer_list) { status = bcm63xx_hsspi_do_txrx(spi, t); if (status) break; msg->actual_length += t->len; if (t->delay_usecs) udelay(t->delay_usecs); if (t->cs_change) bcm63xx_hsspi_set_cs(bs, spi->chip_select, false); } mutex_lock(&bs->bus_mutex); reg = __raw_readl(bs->regs + HSSPI_GLOBAL_CTRL_REG); reg &= ~GLOBAL_CTRL_CS_POLARITY_MASK; reg |= bs->cs_polarity; __raw_writel(reg, bs->regs + HSSPI_GLOBAL_CTRL_REG); mutex_unlock(&bs->bus_mutex); msg->status = status; spi_finalize_current_message(master); return 0; } static irqreturn_t bcm63xx_hsspi_interrupt(int irq, void *dev_id) { struct bcm63xx_hsspi *bs = (struct bcm63xx_hsspi *)dev_id; if (__raw_readl(bs->regs + HSSPI_INT_STATUS_MASKED_REG) == 0) return IRQ_NONE; __raw_writel(HSSPI_INT_CLEAR_ALL, bs->regs + HSSPI_INT_STATUS_REG); __raw_writel(0, bs->regs + HSSPI_INT_MASK_REG); complete(&bs->done); return IRQ_HANDLED; } static int bcm63xx_hsspi_probe(struct platform_device *pdev) { struct spi_master *master; struct bcm63xx_hsspi *bs; struct resource *res_mem; void __iomem *regs; struct device *dev = &pdev->dev; struct clk *clk; int irq, ret; u32 reg, rate, num_cs = HSSPI_SPI_MAX_CS; irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(dev, "no irq: %d\n", irq); return irq; } res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); regs = devm_ioremap_resource(dev, res_mem); if (IS_ERR(regs)) return PTR_ERR(regs); clk = devm_clk_get(dev, "hsspi"); if (IS_ERR(clk)) return PTR_ERR(clk); rate = clk_get_rate(clk); if (!rate) { struct clk *pll_clk = devm_clk_get(dev, "pll"); if (IS_ERR(pll_clk)) return PTR_ERR(pll_clk); rate = clk_get_rate(pll_clk); if (!rate) return -EINVAL; } ret = clk_prepare_enable(clk); if (ret) return ret; master = spi_alloc_master(&pdev->dev, sizeof(*bs)); if (!master) { ret = -ENOMEM; goto out_disable_clk; } bs = spi_master_get_devdata(master); bs->pdev = pdev; bs->clk = clk; bs->regs = regs; bs->speed_hz = rate; bs->fifo = (u8 __iomem *)(bs->regs + HSSPI_FIFO_REG(0)); mutex_init(&bs->bus_mutex); init_completion(&bs->done); master->dev.of_node = dev->of_node; if (!dev->of_node) master->bus_num = HSSPI_BUS_NUM; of_property_read_u32(dev->of_node, "num-cs", &num_cs); if (num_cs > 8) { dev_warn(dev, "unsupported number of cs (%i), reducing to 8\n", num_cs); num_cs = HSSPI_SPI_MAX_CS; } master->num_chipselect = num_cs; master->setup = bcm63xx_hsspi_setup; master->transfer_one_message = bcm63xx_hsspi_transfer_one; master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_RX_DUAL | SPI_TX_DUAL; master->bits_per_word_mask = SPI_BPW_MASK(8); master->auto_runtime_pm = true; platform_set_drvdata(pdev, master); /* Initialize the hardware */ __raw_writel(0, bs->regs + HSSPI_INT_MASK_REG); /* clean up any pending interrupts */ __raw_writel(HSSPI_INT_CLEAR_ALL, bs->regs + HSSPI_INT_STATUS_REG); /* read out default CS polarities */ reg = __raw_readl(bs->regs + HSSPI_GLOBAL_CTRL_REG); bs->cs_polarity = reg & GLOBAL_CTRL_CS_POLARITY_MASK; __raw_writel(reg | GLOBAL_CTRL_CLK_GATE_SSOFF, bs->regs + HSSPI_GLOBAL_CTRL_REG); ret = devm_request_irq(dev, irq, bcm63xx_hsspi_interrupt, IRQF_SHARED, pdev->name, bs); if (ret) goto out_put_master; /* register and we are done */ ret = devm_spi_register_master(dev, master); if (ret) goto out_put_master; return 0; out_put_master: spi_master_put(master); out_disable_clk: clk_disable_unprepare(clk); return ret; } static int bcm63xx_hsspi_remove(struct platform_device *pdev) { struct spi_master *master = platform_get_drvdata(pdev); struct bcm63xx_hsspi *bs = spi_master_get_devdata(master); /* reset the hardware and block queue progress */ __raw_writel(0, bs->regs + HSSPI_INT_MASK_REG); clk_disable_unprepare(bs->clk); return 0; } #ifdef CONFIG_PM_SLEEP static int bcm63xx_hsspi_suspend(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); struct bcm63xx_hsspi *bs = spi_master_get_devdata(master); spi_master_suspend(master); clk_disable_unprepare(bs->clk); return 0; } static int bcm63xx_hsspi_resume(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); struct bcm63xx_hsspi *bs = spi_master_get_devdata(master); int ret; ret = clk_prepare_enable(bs->clk); if (ret) return ret; spi_master_resume(master); return 0; } #endif static SIMPLE_DEV_PM_OPS(bcm63xx_hsspi_pm_ops, bcm63xx_hsspi_suspend, bcm63xx_hsspi_resume); static const struct of_device_id bcm63xx_hsspi_of_match[] = { { .compatible = "brcm,bcm6328-hsspi", }, { }, }; MODULE_DEVICE_TABLE(of, bcm63xx_hsspi_of_match); static struct platform_driver bcm63xx_hsspi_driver = { .driver = { .name = "bcm63xx-hsspi", .pm = &bcm63xx_hsspi_pm_ops, .of_match_table = bcm63xx_hsspi_of_match, }, .probe = bcm63xx_hsspi_probe, .remove = bcm63xx_hsspi_remove, }; module_platform_driver(bcm63xx_hsspi_driver); MODULE_ALIAS("platform:bcm63xx_hsspi"); MODULE_DESCRIPTION("Broadcom BCM63xx High Speed SPI Controller driver"); MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>"); MODULE_LICENSE("GPL");