spi: bcm63xx-hsspi: add bcm63xx HSSPI driver
Add a driver for the High Speed SPI controller found on newer BCM63XX SoCs.
It does feature some new modes like 3-wire or dual spi, but neither of it
is currently implemented.
Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/spi/spi-bcm63xx-hsspi.c b/drivers/spi/spi-bcm63xx-hsspi.c
new file mode 100644
index 0000000..bc8d848
--- /dev/null
+++ b/drivers/spi/spi-bcm63xx-hsspi.c
@@ -0,0 +1,484 @@
+/*
+ * 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/workqueue.h>
+#include <linux/mutex.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_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_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 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 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 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;
+
+ __raw_writel(0 << MODE_CTRL_PREPENDBYTE_CNT_SHIFT |
+ 2 << MODE_CTRL_MULTIDATA_WR_STRT_SHIFT |
+ 2 << MODE_CTRL_MULTIDATA_RD_STRT_SHIFT | 0xff,
+ bs->regs + HSSPI_PROFILE_MODE_CTRL_REG(chip_select));
+
+ while (pending > 0) {
+ int curr_step = min_t(int, step_size, pending);
+
+ init_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;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(dev, "no irq\n");
+ return -ENXIO;
+ }
+
+ res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ regs = devm_request_and_ioremap(dev, res_mem);
+ if (IS_ERR(regs))
+ return PTR_ERR(regs);
+
+ clk = clk_get(dev, "hsspi");
+
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ rate = clk_get_rate(clk);
+ if (!rate) {
+ ret = -EINVAL;
+ goto out_put_clk;
+ }
+
+ clk_prepare_enable(clk);
+
+ 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);
+
+ master->bus_num = HSSPI_BUS_NUM;
+ master->num_chipselect = 8;
+ master->setup = bcm63xx_hsspi_setup;
+ master->transfer_one_message = bcm63xx_hsspi_transfer_one;
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+ 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 = spi_register_master(master);
+ if (ret)
+ goto out_put_master;
+
+ return 0;
+
+out_put_master:
+ spi_master_put(master);
+out_disable_clk:
+ clk_disable_unprepare(clk);
+out_put_clk:
+ clk_put(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);
+
+ spi_unregister_master(master);
+
+ /* reset the hardware and block queue progress */
+ __raw_writel(0, bs->regs + HSSPI_INT_MASK_REG);
+ clk_disable_unprepare(bs->clk);
+ clk_put(bs->clk);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+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(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);
+
+ clk_enable(bs->clk);
+ spi_master_resume(master);
+
+ return 0;
+}
+
+static const struct dev_pm_ops bcm63xx_hsspi_pm_ops = {
+ .suspend = bcm63xx_hsspi_suspend,
+ .resume = bcm63xx_hsspi_resume,
+};
+
+#define BCM63XX_HSSPI_PM_OPS (&bcm63xx_hsspi_pm_ops)
+#else
+#define BCM63XX_HSSPI_PM_OPS NULL
+#endif
+
+
+
+static struct platform_driver bcm63xx_hsspi_driver = {
+ .driver = {
+ .name = "bcm63xx-hsspi",
+ .owner = THIS_MODULE,
+ .pm = BCM63XX_HSSPI_PM_OPS,
+ },
+ .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");