diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/spi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/spi/spi-mxs.c | 431 |
3 files changed, 439 insertions, 0 deletions
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 5f84b5563c2d..6992b30b4e42 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -364,6 +364,13 @@ config SPI_STMP3XXX help SPI driver for Freescale STMP37xx/378x SoC SSP interface +config SPI_MXS + tristate "Freescale MXS SPI controller" + depends on ARCH_MXS + select STMP_DEVICE + help + SPI driver for Freescale MXS devices. + config SPI_TEGRA tristate "Nvidia Tegra SPI controller" depends on ARCH_TEGRA && (TEGRA_SYSTEM_DMA || TEGRA20_APB_DMA) diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 3920dcf4c740..3b72d87b3309 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -36,6 +36,7 @@ obj-$(CONFIG_SPI_LM70_LLP) += spi-lm70llp.o obj-$(CONFIG_SPI_MPC512x_PSC) += spi-mpc512x-psc.o obj-$(CONFIG_SPI_MPC52xx_PSC) += spi-mpc52xx-psc.o obj-$(CONFIG_SPI_MPC52xx) += spi-mpc52xx.o +obj-$(CONFIG_SPI_MXS) += spi-mxs.o obj-$(CONFIG_SPI_NUC900) += spi-nuc900.o obj-$(CONFIG_SPI_OC_TINY) += spi-oc-tiny.o obj-$(CONFIG_SPI_OMAP_UWIRE) += spi-omap-uwire.o diff --git a/drivers/spi/spi-mxs.c b/drivers/spi/spi-mxs.c new file mode 100644 index 000000000000..7bf826f5af59 --- /dev/null +++ b/drivers/spi/spi-mxs.c @@ -0,0 +1,431 @@ +/* + * Freescale MXS SPI master driver + * + * Copyright 2012 DENX Software Engineering, GmbH. + * Copyright 2012 Freescale Semiconductor, Inc. + * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved. + * + * Rework and transition to new API by: + * Marek Vasut <marex@denx.de> + * + * Based on previous attempt by: + * Fabio Estevam <fabio.estevam@freescale.com> + * + * Based on code from U-Boot bootloader by: + * Marek Vasut <marex@denx.de> + * + * Based on spi-stmp.c, which is: + * Author: Dmitry Pervushin <dimka@embeddedalley.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/ioport.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_gpio.h> +#include <linux/platform_device.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/highmem.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/completion.h> +#include <linux/gpio.h> +#include <linux/regulator/consumer.h> +#include <linux/module.h> +#include <linux/fsl/mxs-dma.h> +#include <linux/pinctrl/consumer.h> +#include <linux/stmp_device.h> +#include <linux/spi/spi.h> +#include <linux/spi/mxs-spi.h> + +#define DRIVER_NAME "mxs-spi" + +#define SSP_TIMEOUT 1000 /* 1000 ms */ + +struct mxs_spi { + struct mxs_ssp ssp; +}; + +static int mxs_spi_setup_transfer(struct spi_device *dev, + struct spi_transfer *t) +{ + struct mxs_spi *spi = spi_master_get_devdata(dev->master); + struct mxs_ssp *ssp = &spi->ssp; + uint8_t bits_per_word; + uint32_t hz = 0; + + bits_per_word = dev->bits_per_word; + if (t && t->bits_per_word) + bits_per_word = t->bits_per_word; + + if (bits_per_word != 8) { + dev_err(&dev->dev, "%s, unsupported bits_per_word=%d\n", + __func__, bits_per_word); + return -EINVAL; + } + + hz = dev->max_speed_hz; + if (t && t->speed_hz) + hz = min(hz, t->speed_hz); + if (hz == 0) { + dev_err(&dev->dev, "Cannot continue with zero clock\n"); + return -EINVAL; + } + + mxs_ssp_set_clk_rate(ssp, hz); + + writel(BF_SSP_CTRL1_SSP_MODE(BV_SSP_CTRL1_SSP_MODE__SPI) | + BF_SSP_CTRL1_WORD_LENGTH + (BV_SSP_CTRL1_WORD_LENGTH__EIGHT_BITS) | + ((dev->mode & SPI_CPOL) ? BM_SSP_CTRL1_POLARITY : 0) | + ((dev->mode & SPI_CPHA) ? BM_SSP_CTRL1_PHASE : 0), + ssp->base + HW_SSP_CTRL1(ssp)); + + writel(0x0, ssp->base + HW_SSP_CMD0); + writel(0x0, ssp->base + HW_SSP_CMD1); + + return 0; +} + +static int mxs_spi_setup(struct spi_device *dev) +{ + int err = 0; + + if (!dev->bits_per_word) + dev->bits_per_word = 8; + + if (dev->mode & ~(SPI_CPOL | SPI_CPHA)) + return -EINVAL; + + err = mxs_spi_setup_transfer(dev, NULL); + if (err) { + dev_err(&dev->dev, + "Failed to setup transfer, error = %d\n", err); + } + + return err; +} + +static uint32_t mxs_spi_cs_to_reg(unsigned cs) +{ + uint32_t select = 0; + + /* + * i.MX28 Datasheet: 17.10.1: HW_SSP_CTRL0 + * + * The bits BM_SSP_CTRL0_WAIT_FOR_CMD and BM_SSP_CTRL0_WAIT_FOR_IRQ + * in HW_SSP_CTRL0 register do have multiple usage, please refer to + * the datasheet for further details. In SPI mode, they are used to + * toggle the chip-select lines (nCS pins). + */ + if (cs & 1) + select |= BM_SSP_CTRL0_WAIT_FOR_CMD; + if (cs & 2) + select |= BM_SSP_CTRL0_WAIT_FOR_IRQ; + + return select; +} + +static void mxs_spi_set_cs(struct mxs_spi *spi, unsigned cs) +{ + const uint32_t mask = + BM_SSP_CTRL0_WAIT_FOR_CMD | BM_SSP_CTRL0_WAIT_FOR_IRQ; + uint32_t select; + struct mxs_ssp *ssp = &spi->ssp; + + writel(mask, ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR); + select = mxs_spi_cs_to_reg(cs); + writel(select, ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET); +} + +static inline void mxs_spi_enable(struct mxs_spi *spi) +{ + struct mxs_ssp *ssp = &spi->ssp; + + writel(BM_SSP_CTRL0_LOCK_CS, + ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET); + writel(BM_SSP_CTRL0_IGNORE_CRC, + ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR); +} + +static inline void mxs_spi_disable(struct mxs_spi *spi) +{ + struct mxs_ssp *ssp = &spi->ssp; + + writel(BM_SSP_CTRL0_LOCK_CS, + ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR); + writel(BM_SSP_CTRL0_IGNORE_CRC, + ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET); +} + +static int mxs_ssp_wait(struct mxs_spi *spi, int offset, int mask, bool set) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(SSP_TIMEOUT); + struct mxs_ssp *ssp = &spi->ssp; + uint32_t reg; + + while (1) { + reg = readl_relaxed(ssp->base + offset); + + if (set && ((reg & mask) == mask)) + break; + + if (!set && ((~reg & mask) == mask)) + break; + + udelay(1); + + if (time_after(jiffies, timeout)) + return -ETIMEDOUT; + } + return 0; +} + +static int mxs_spi_txrx_pio(struct mxs_spi *spi, int cs, + unsigned char *buf, int len, + int *first, int *last, int write) +{ + struct mxs_ssp *ssp = &spi->ssp; + + if (*first) + mxs_spi_enable(spi); + + mxs_spi_set_cs(spi, cs); + + while (len--) { + if (*last && len == 0) + mxs_spi_disable(spi); + + if (ssp->devid == IMX23_SSP) { + writel(BM_SSP_CTRL0_XFER_COUNT, + ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR); + writel(1, + ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET); + } else { + writel(1, ssp->base + HW_SSP_XFER_SIZE); + } + + if (write) + writel(BM_SSP_CTRL0_READ, + ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR); + else + writel(BM_SSP_CTRL0_READ, + ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET); + + writel(BM_SSP_CTRL0_RUN, + ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET); + + if (mxs_ssp_wait(spi, HW_SSP_CTRL0, BM_SSP_CTRL0_RUN, 1)) + return -ETIMEDOUT; + + if (write) + writel(*buf, ssp->base + HW_SSP_DATA(ssp)); + + writel(BM_SSP_CTRL0_DATA_XFER, + ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET); + + if (!write) { + if (mxs_ssp_wait(spi, HW_SSP_STATUS(ssp), + BM_SSP_STATUS_FIFO_EMPTY, 0)) + return -ETIMEDOUT; + + *buf = (readl(ssp->base + HW_SSP_DATA(ssp)) & 0xff); + } + + if (mxs_ssp_wait(spi, HW_SSP_CTRL0, BM_SSP_CTRL0_RUN, 0)) + return -ETIMEDOUT; + + buf++; + } + + if (len <= 0) + return 0; + + return -ETIMEDOUT; +} + +static int mxs_spi_transfer_one(struct spi_master *master, + struct spi_message *m) +{ + struct mxs_spi *spi = spi_master_get_devdata(master); + struct mxs_ssp *ssp = &spi->ssp; + int first, last; + struct spi_transfer *t, *tmp_t; + int status = 0; + int cs; + + first = last = 0; + + cs = m->spi->chip_select; + + list_for_each_entry_safe(t, tmp_t, &m->transfers, transfer_list) { + + status = mxs_spi_setup_transfer(m->spi, t); + if (status) + break; + + if (&t->transfer_list == m->transfers.next) + first = 1; + if (&t->transfer_list == m->transfers.prev) + last = 1; + if (t->rx_buf && t->tx_buf) { + dev_err(ssp->dev, + "Cannot send and receive simultaneously\n"); + status = -EINVAL; + break; + } + + if (t->tx_buf) + status = mxs_spi_txrx_pio(spi, cs, (void *)t->tx_buf, + t->len, &first, &last, 1); + if (t->rx_buf) + status = mxs_spi_txrx_pio(spi, cs, t->rx_buf, + t->len, &first, &last, 0); + + m->actual_length += t->len; + if (status) + break; + + first = last = 0; + } + + m->status = 0; + spi_finalize_current_message(master); + + return status; +} + +static const struct of_device_id mxs_spi_dt_ids[] = { + { .compatible = "fsl,imx23-spi", .data = (void *) IMX23_SSP, }, + { .compatible = "fsl,imx28-spi", .data = (void *) IMX28_SSP, }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, mxs_spi_dt_ids); + +static int __devinit mxs_spi_probe(struct platform_device *pdev) +{ + const struct of_device_id *of_id = + of_match_device(mxs_spi_dt_ids, &pdev->dev); + struct device_node *np = pdev->dev.of_node; + struct spi_master *master; + struct mxs_spi *spi; + struct mxs_ssp *ssp; + struct resource *iores; + struct pinctrl *pinctrl; + struct clk *clk; + void __iomem *base; + int devid; + int ret = 0; + + iores = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!iores) + return -EINVAL; + + base = devm_request_and_ioremap(&pdev->dev, iores); + if (!base) + return -EADDRNOTAVAIL; + + pinctrl = devm_pinctrl_get_select_default(&pdev->dev); + if (IS_ERR(pinctrl)) + return PTR_ERR(pinctrl); + + clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + if (np) + devid = (enum mxs_ssp_id) of_id->data; + else + devid = pdev->id_entry->driver_data; + + master = spi_alloc_master(&pdev->dev, sizeof(*spi)); + if (!master) + return -ENOMEM; + + master->transfer_one_message = mxs_spi_transfer_one; + master->setup = mxs_spi_setup; + master->mode_bits = SPI_CPOL | SPI_CPHA; + master->num_chipselect = 3; + master->dev.of_node = np; + master->flags = SPI_MASTER_HALF_DUPLEX; + + spi = spi_master_get_devdata(master); + ssp = &spi->ssp; + ssp->dev = &pdev->dev; + ssp->clk = clk; + ssp->base = base; + ssp->devid = devid; + + clk_prepare_enable(ssp->clk); + ssp->clk_rate = clk_get_rate(ssp->clk) / 1000; + + stmp_reset_block(ssp->base); + + platform_set_drvdata(pdev, master); + + ret = spi_register_master(master); + if (ret) { + dev_err(&pdev->dev, "Cannot register SPI master, %d\n", ret); + goto out_master_free; + } + + return 0; + +out_master_free: + platform_set_drvdata(pdev, NULL); + clk_disable_unprepare(ssp->clk); + spi_master_put(master); + return ret; +} + +static int __devexit mxs_spi_remove(struct platform_device *pdev) +{ + struct spi_master *master; + struct mxs_spi *spi; + struct mxs_ssp *ssp; + + master = platform_get_drvdata(pdev); + spi = spi_master_get_devdata(master); + ssp = &spi->ssp; + + spi_unregister_master(master); + + platform_set_drvdata(pdev, NULL); + + clk_disable_unprepare(ssp->clk); + + spi_master_put(master); + + return 0; +} + +static struct platform_driver mxs_spi_driver = { + .probe = mxs_spi_probe, + .remove = __devexit_p(mxs_spi_remove), + .driver = { + .name = DRIVER_NAME, + .owner = THIS_MODULE, + .of_match_table = mxs_spi_dt_ids, + }, +}; + +module_platform_driver(mxs_spi_driver); + +MODULE_AUTHOR("Marek Vasut <marex@denx.de>"); +MODULE_DESCRIPTION("MXS SPI master driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:mxs-spi"); |