diff options
| -rw-r--r-- | drivers/spi/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/spi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/spi/spi-axi-spi-engine.c | 591 |
3 files changed, 600 insertions, 0 deletions
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 7caf18cb3e5e..d84adceb9b89 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -83,6 +83,14 @@ config SPI_AU1550 If you say yes to this option, support will be included for the PSC SPI controller found on Au1550, Au1200 and Au1300 series. +config SPI_AXI_SPI_ENGINE + tristate "Analog Devices AXI SPI Engine controller" + depends on HAS_IOMEM + help + This enables support for the Analog Devices AXI SPI Engine SPI controller. + It is part of the SPI Engine framework that is used in some Analog Devices + reference designs for FPGAs. + config SPI_BCM2835 tristate "BCM2835 SPI controller" depends on GPIOLIB diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 8991ffce6e12..7ad880684a85 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -15,6 +15,7 @@ obj-$(CONFIG_SPI_ALTERA) += spi-altera.o obj-$(CONFIG_SPI_ATMEL) += spi-atmel.o obj-$(CONFIG_SPI_ATH79) += spi-ath79.o obj-$(CONFIG_SPI_AU1550) += spi-au1550.o +obj-$(CONFIG_SPI_AXI_SPI_ENGINE) += spi-axi-spi-engine.o obj-$(CONFIG_SPI_BCM2835) += spi-bcm2835.o obj-$(CONFIG_SPI_BCM2835AUX) += spi-bcm2835aux.o obj-$(CONFIG_SPI_BCM53XX) += spi-bcm53xx.o diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c new file mode 100644 index 000000000000..c968ab210a51 --- /dev/null +++ b/drivers/spi/spi-axi-spi-engine.c @@ -0,0 +1,591 @@ +/* + * SPI-Engine SPI controller driver + * Copyright 2015 Analog Devices Inc. + * Author: Lars-Peter Clausen <lars@metafoo.de> + * + * Licensed under the GPL-2. + */ + +#include <linux/clk.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/spi/spi.h> + +#define SPI_ENGINE_VERSION_MAJOR(x) ((x >> 16) & 0xff) +#define SPI_ENGINE_VERSION_MINOR(x) ((x >> 8) & 0xff) +#define SPI_ENGINE_VERSION_PATCH(x) (x & 0xff) + +#define SPI_ENGINE_REG_VERSION 0x00 + +#define SPI_ENGINE_REG_RESET 0x40 + +#define SPI_ENGINE_REG_INT_ENABLE 0x80 +#define SPI_ENGINE_REG_INT_PENDING 0x84 +#define SPI_ENGINE_REG_INT_SOURCE 0x88 + +#define SPI_ENGINE_REG_SYNC_ID 0xc0 + +#define SPI_ENGINE_REG_CMD_FIFO_ROOM 0xd0 +#define SPI_ENGINE_REG_SDO_FIFO_ROOM 0xd4 +#define SPI_ENGINE_REG_SDI_FIFO_LEVEL 0xd8 + +#define SPI_ENGINE_REG_CMD_FIFO 0xe0 +#define SPI_ENGINE_REG_SDO_DATA_FIFO 0xe4 +#define SPI_ENGINE_REG_SDI_DATA_FIFO 0xe8 +#define SPI_ENGINE_REG_SDI_DATA_FIFO_PEEK 0xec + +#define SPI_ENGINE_INT_CMD_ALMOST_EMPTY BIT(0) +#define SPI_ENGINE_INT_SDO_ALMOST_EMPTY BIT(1) +#define SPI_ENGINE_INT_SDI_ALMOST_FULL BIT(2) +#define SPI_ENGINE_INT_SYNC BIT(3) + +#define SPI_ENGINE_CONFIG_CPHA BIT(0) +#define SPI_ENGINE_CONFIG_CPOL BIT(1) +#define SPI_ENGINE_CONFIG_3WIRE BIT(2) + +#define SPI_ENGINE_INST_TRANSFER 0x0 +#define SPI_ENGINE_INST_ASSERT 0x1 +#define SPI_ENGINE_INST_WRITE 0x2 +#define SPI_ENGINE_INST_MISC 0x3 + +#define SPI_ENGINE_CMD_REG_CLK_DIV 0x0 +#define SPI_ENGINE_CMD_REG_CONFIG 0x1 + +#define SPI_ENGINE_MISC_SYNC 0x0 +#define SPI_ENGINE_MISC_SLEEP 0x1 + +#define SPI_ENGINE_TRANSFER_WRITE 0x1 +#define SPI_ENGINE_TRANSFER_READ 0x2 + +#define SPI_ENGINE_CMD(inst, arg1, arg2) \ + (((inst) << 12) | ((arg1) << 8) | (arg2)) + +#define SPI_ENGINE_CMD_TRANSFER(flags, n) \ + SPI_ENGINE_CMD(SPI_ENGINE_INST_TRANSFER, (flags), (n)) +#define SPI_ENGINE_CMD_ASSERT(delay, cs) \ + SPI_ENGINE_CMD(SPI_ENGINE_INST_ASSERT, (delay), (cs)) +#define SPI_ENGINE_CMD_WRITE(reg, val) \ + SPI_ENGINE_CMD(SPI_ENGINE_INST_WRITE, (reg), (val)) +#define SPI_ENGINE_CMD_SLEEP(delay) \ + SPI_ENGINE_CMD(SPI_ENGINE_INST_MISC, SPI_ENGINE_MISC_SLEEP, (delay)) +#define SPI_ENGINE_CMD_SYNC(id) \ + SPI_ENGINE_CMD(SPI_ENGINE_INST_MISC, SPI_ENGINE_MISC_SYNC, (id)) + +struct spi_engine_program { + unsigned int length; + uint16_t instructions[]; +}; + +struct spi_engine { + struct clk *clk; + struct clk *ref_clk; + + spinlock_t lock; + + void __iomem *base; + + struct spi_message *msg; + struct spi_engine_program *p; + unsigned cmd_length; + const uint16_t *cmd_buf; + + struct spi_transfer *tx_xfer; + unsigned int tx_length; + const uint8_t *tx_buf; + + struct spi_transfer *rx_xfer; + unsigned int rx_length; + uint8_t *rx_buf; + + unsigned int sync_id; + unsigned int completed_id; + + unsigned int int_enable; +}; + +static void spi_engine_program_add_cmd(struct spi_engine_program *p, + bool dry, uint16_t cmd) +{ + if (!dry) + p->instructions[p->length] = cmd; + p->length++; +} + +static unsigned int spi_engine_get_config(struct spi_device *spi) +{ + unsigned int config = 0; + + if (spi->mode & SPI_CPOL) + config |= SPI_ENGINE_CONFIG_CPOL; + if (spi->mode & SPI_CPHA) + config |= SPI_ENGINE_CONFIG_CPHA; + if (spi->mode & SPI_3WIRE) + config |= SPI_ENGINE_CONFIG_3WIRE; + + return config; +} + +static unsigned int spi_engine_get_clk_div(struct spi_engine *spi_engine, + struct spi_device *spi, struct spi_transfer *xfer) +{ + unsigned int clk_div; + + clk_div = DIV_ROUND_UP(clk_get_rate(spi_engine->ref_clk), + xfer->speed_hz * 2); + if (clk_div > 255) + clk_div = 255; + else if (clk_div > 0) + clk_div -= 1; + + return clk_div; +} + +static void spi_engine_gen_xfer(struct spi_engine_program *p, bool dry, + struct spi_transfer *xfer) +{ + unsigned int len = xfer->len; + + while (len) { + unsigned int n = min(len, 256U); + unsigned int flags = 0; + + if (xfer->tx_buf) + flags |= SPI_ENGINE_TRANSFER_WRITE; + if (xfer->rx_buf) + flags |= SPI_ENGINE_TRANSFER_READ; + + spi_engine_program_add_cmd(p, dry, + SPI_ENGINE_CMD_TRANSFER(flags, n - 1)); + len -= n; + } +} + +static void spi_engine_gen_sleep(struct spi_engine_program *p, bool dry, + struct spi_engine *spi_engine, unsigned int clk_div, unsigned int delay) +{ + unsigned int spi_clk = clk_get_rate(spi_engine->ref_clk); + unsigned int t; + + if (delay == 0) + return; + + t = DIV_ROUND_UP(delay * spi_clk, (clk_div + 1) * 2); + while (t) { + unsigned int n = min(t, 256U); + + spi_engine_program_add_cmd(p, dry, SPI_ENGINE_CMD_SLEEP(n - 1)); + t -= n; + } +} + +static void spi_engine_gen_cs(struct spi_engine_program *p, bool dry, + struct spi_device *spi, bool assert) +{ + unsigned int mask = 0xff; + + if (assert) + mask ^= BIT(spi->chip_select); + + spi_engine_program_add_cmd(p, dry, SPI_ENGINE_CMD_ASSERT(1, mask)); +} + +static int spi_engine_compile_message(struct spi_engine *spi_engine, + struct spi_message *msg, bool dry, struct spi_engine_program *p) +{ + struct spi_device *spi = msg->spi; + struct spi_transfer *xfer; + int clk_div, new_clk_div; + bool cs_change = true; + + clk_div = -1; + + spi_engine_program_add_cmd(p, dry, + SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CONFIG, + spi_engine_get_config(spi))); + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + new_clk_div = spi_engine_get_clk_div(spi_engine, spi, xfer); + if (new_clk_div != clk_div) { + clk_div = new_clk_div; + spi_engine_program_add_cmd(p, dry, + SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CLK_DIV, + clk_div)); + } + + if (cs_change) + spi_engine_gen_cs(p, dry, spi, true); + + spi_engine_gen_xfer(p, dry, xfer); + spi_engine_gen_sleep(p, dry, spi_engine, clk_div, + xfer->delay_usecs); + + cs_change = xfer->cs_change; + if (list_is_last(&xfer->transfer_list, &msg->transfers)) + cs_change = !cs_change; + + if (cs_change) + spi_engine_gen_cs(p, dry, spi, false); + } + + return 0; +} + +static void spi_engine_xfer_next(struct spi_engine *spi_engine, + struct spi_transfer **_xfer) +{ + struct spi_message *msg = spi_engine->msg; + struct spi_transfer *xfer = *_xfer; + + if (!xfer) { + xfer = list_first_entry(&msg->transfers, + struct spi_transfer, transfer_list); + } else if (list_is_last(&xfer->transfer_list, &msg->transfers)) { + xfer = NULL; + } else { + xfer = list_next_entry(xfer, transfer_list); + } + + *_xfer = xfer; +} + +static void spi_engine_tx_next(struct spi_engine *spi_engine) +{ + struct spi_transfer *xfer = spi_engine->tx_xfer; + + do { + spi_engine_xfer_next(spi_engine, &xfer); + } while (xfer && !xfer->tx_buf); + + spi_engine->tx_xfer = xfer; + if (xfer) { + spi_engine->tx_length = xfer->len; + spi_engine->tx_buf = xfer->tx_buf; + } else { + spi_engine->tx_buf = NULL; + } +} + +static void spi_engine_rx_next(struct spi_engine *spi_engine) +{ + struct spi_transfer *xfer = spi_engine->rx_xfer; + + do { + spi_engine_xfer_next(spi_engine, &xfer); + } while (xfer && !xfer->rx_buf); + + spi_engine->rx_xfer = xfer; + if (xfer) { + spi_engine->rx_length = xfer->len; + spi_engine->rx_buf = xfer->rx_buf; + } else { + spi_engine->rx_buf = NULL; + } +} + +static bool spi_engine_write_cmd_fifo(struct spi_engine *spi_engine) +{ + void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_CMD_FIFO; + unsigned int n, m, i; + const uint16_t *buf; + + n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_CMD_FIFO_ROOM); + while (n && spi_engine->cmd_length) { + m = min(n, spi_engine->cmd_length); + buf = spi_engine->cmd_buf; + for (i = 0; i < m; i++) + writel_relaxed(buf[i], addr); + spi_engine->cmd_buf += m; + spi_engine->cmd_length -= m; + n -= m; + } + + return spi_engine->cmd_length != 0; +} + +static bool spi_engine_write_tx_fifo(struct spi_engine *spi_engine) +{ + void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_SDO_DATA_FIFO; + unsigned int n, m, i; + const uint8_t *buf; + + n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_SDO_FIFO_ROOM); + while (n && spi_engine->tx_length) { + m = min(n, spi_engine->tx_length); + buf = spi_engine->tx_buf; + for (i = 0; i < m; i++) + writel_relaxed(buf[i], addr); + spi_engine->tx_buf += m; + spi_engine->tx_length -= m; + n -= m; + if (spi_engine->tx_length == 0) + spi_engine_tx_next(spi_engine); + } + + return spi_engine->tx_length != 0; +} + +static bool spi_engine_read_rx_fifo(struct spi_engine *spi_engine) +{ + void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_SDI_DATA_FIFO; + unsigned int n, m, i; + uint8_t *buf; + + n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_SDI_FIFO_LEVEL); + while (n && spi_engine->rx_length) { + m = min(n, spi_engine->rx_length); + buf = spi_engine->rx_buf; + for (i = 0; i < m; i++) + buf[i] = readl_relaxed(addr); + spi_engine->rx_buf += m; + spi_engine->rx_length -= m; + n -= m; + if (spi_engine->rx_length == 0) + spi_engine_rx_next(spi_engine); + } + + return spi_engine->rx_length != 0; +} + +static irqreturn_t spi_engine_irq(int irq, void *devid) +{ + struct spi_master *master = devid; + struct spi_engine *spi_engine = spi_master_get_devdata(master); + unsigned int disable_int = 0; + unsigned int pending; + + pending = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_INT_PENDING); + + if (pending & SPI_ENGINE_INT_SYNC) { + writel_relaxed(SPI_ENGINE_INT_SYNC, + spi_engine->base + SPI_ENGINE_REG_INT_PENDING); + spi_engine->completed_id = readl_relaxed( + spi_engine->base + SPI_ENGINE_REG_SYNC_ID); + } + + spin_lock(&spi_engine->lock); + + if (pending & SPI_ENGINE_INT_CMD_ALMOST_EMPTY) { + if (!spi_engine_write_cmd_fifo(spi_engine)) + disable_int |= SPI_ENGINE_INT_CMD_ALMOST_EMPTY; + } + + if (pending & SPI_ENGINE_INT_SDO_ALMOST_EMPTY) { + if (!spi_engine_write_tx_fifo(spi_engine)) + disable_int |= SPI_ENGINE_INT_SDO_ALMOST_EMPTY; + } + + if (pending & (SPI_ENGINE_INT_SDI_ALMOST_FULL | SPI_ENGINE_INT_SYNC)) { + if (!spi_engine_read_rx_fifo(spi_engine)) + disable_int |= SPI_ENGINE_INT_SDI_ALMOST_FULL; + } + + if (pending & SPI_ENGINE_INT_SYNC) { + if (spi_engine->msg && + spi_engine->completed_id == spi_engine->sync_id) { + struct spi_message *msg = spi_engine->msg; + + kfree(spi_engine->p); + msg->status = 0; + msg->actual_length = msg->frame_length; + spi_engine->msg = NULL; + spi_finalize_current_message(master); + disable_int |= SPI_ENGINE_INT_SYNC; + } + } + + if (disable_int) { + spi_engine->int_enable &= ~disable_int; + writel_relaxed(spi_engine->int_enable, + spi_engine->base + SPI_ENGINE_REG_INT_ENABLE); + } + + spin_unlock(&spi_engine->lock); + + return IRQ_HANDLED; +} + +static int spi_engine_transfer_one_message(struct spi_master *master, + struct spi_message *msg) +{ + struct spi_engine_program p_dry, *p; + struct spi_engine *spi_engine = spi_master_get_devdata(master); + unsigned int int_enable = 0; + unsigned long flags; + size_t size; + + p_dry.length = 0; + spi_engine_compile_message(spi_engine, msg, true, &p_dry); + + size = sizeof(*p->instructions) * (p_dry.length + 1); + p = kzalloc(sizeof(*p) + size, GFP_KERNEL); + if (!p) + return -ENOMEM; + spi_engine_compile_message(spi_engine, msg, false, p); + + spin_lock_irqsave(&spi_engine->lock, flags); + spi_engine->sync_id = (spi_engine->sync_id + 1) & 0xff; + spi_engine_program_add_cmd(p, false, + SPI_ENGINE_CMD_SYNC(spi_engine->sync_id)); + + spi_engine->msg = msg; + spi_engine->p = p; + + spi_engine->cmd_buf = p->instructions; + spi_engine->cmd_length = p->length; + if (spi_engine_write_cmd_fifo(spi_engine)) + int_enable |= SPI_ENGINE_INT_CMD_ALMOST_EMPTY; + + spi_engine_tx_next(spi_engine); + if (spi_engine_write_tx_fifo(spi_engine)) + int_enable |= SPI_ENGINE_INT_SDO_ALMOST_EMPTY; + + spi_engine_rx_next(spi_engine); + if (spi_engine->rx_length != 0) + int_enable |= SPI_ENGINE_INT_SDI_ALMOST_FULL; + + int_enable |= SPI_ENGINE_INT_SYNC; + + writel_relaxed(int_enable, + spi_engine->base + SPI_ENGINE_REG_INT_ENABLE); + spi_engine->int_enable = int_enable; + spin_unlock_irqrestore(&spi_engine->lock, flags); + + return 0; +} + +static int spi_engine_probe(struct platform_device *pdev) +{ + struct spi_engine *spi_engine; + struct spi_master *master; + unsigned int version; + struct resource *res; + int irq; + int ret; + + irq = platform_get_irq(pdev, 0); + if (irq <= 0) + return -ENXIO; + + spi_engine = devm_kzalloc(&pdev->dev, sizeof(*spi_engine), GFP_KERNEL); + if (!spi_engine) + return -ENOMEM; + + master = spi_alloc_master(&pdev->dev, 0); + if (!master) + return -ENOMEM; + + spi_master_set_devdata(master, spi_engine); + + spin_lock_init(&spi_engine->lock); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + spi_engine->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(spi_engine->base)) { + ret = PTR_ERR(spi_engine->base); + goto err_put_master; + } + + version = readl(spi_engine->base + SPI_ENGINE_REG_VERSION); + if (SPI_ENGINE_VERSION_MAJOR(version) != 1) { + dev_err(&pdev->dev, "Unsupported peripheral version %u.%u.%c\n", + SPI_ENGINE_VERSION_MAJOR(version), + SPI_ENGINE_VERSION_MINOR(version), + SPI_ENGINE_VERSION_PATCH(version)); + return -ENODEV; + } + + spi_engine->clk = devm_clk_get(&pdev->dev, "s_axi_aclk"); + if (IS_ERR(spi_engine->clk)) { + ret = PTR_ERR(spi_engine->clk); + goto err_put_master; + } + + spi_engine->ref_clk = devm_clk_get(&pdev->dev, "spi_clk"); + if (IS_ERR(spi_engine->ref_clk)) { + ret = PTR_ERR(spi_engine->ref_clk); + goto err_put_master; + } + + ret = clk_prepare_enable(spi_engine->clk); + if (ret) + goto err_put_master; + + ret = clk_prepare_enable(spi_engine->ref_clk); + if (ret) + goto err_clk_disable; + + writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_RESET); + writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING); + writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE); + + ret = request_irq(irq, spi_engine_irq, 0, pdev->name, master); + if (ret) + goto err_ref_clk_disable; + + master->dev.parent = &pdev->dev; + master->dev.of_node = pdev->dev.of_node; + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_3WIRE; + master->bits_per_word_mask = SPI_BPW_MASK(8); + master->max_speed_hz = clk_get_rate(spi_engine->ref_clk) / 2; + master->transfer_one_message = spi_engine_transfer_one_message; + master->num_chipselect = 8; + + ret = spi_register_master(master); + if (ret) + goto err_free_irq; + + platform_set_drvdata(pdev, master); + + return 0; +err_free_irq: + free_irq(irq, master); +err_ref_clk_disable: + clk_disable_unprepare(spi_engine->ref_clk); +err_clk_disable: + clk_disable_unprepare(spi_engine->clk); +err_put_master: + spi_master_put(master); + return ret; +} + +static int spi_engine_remove(struct platform_device *pdev) +{ + struct spi_master *master = platform_get_drvdata(pdev); + struct spi_engine *spi_engine = spi_master_get_devdata(master); + int irq = platform_get_irq(pdev, 0); + + spi_unregister_master(master); + + free_irq(irq, master); + + writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING); + writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE); + writel_relaxed(0x01, spi_engine->base + SPI_ENGINE_REG_RESET); + + clk_disable_unprepare(spi_engine->ref_clk); + clk_disable_unprepare(spi_engine->clk); + + return 0; +} + +static const struct of_device_id spi_engine_match_table[] = { + { .compatible = "adi,axi-spi-engine-1.00.a" }, + { }, +}; + +static struct platform_driver spi_engine_driver = { + .probe = spi_engine_probe, + .remove = spi_engine_remove, + .driver = { + .name = "spi-engine", + .of_match_table = spi_engine_match_table, + }, +}; +module_platform_driver(spi_engine_driver); + +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); +MODULE_DESCRIPTION("Analog Devices SPI engine peripheral driver"); +MODULE_LICENSE("GPL"); |