This patch adds support of OpenCores tiny SPI driver. http://opencores.org/project,tiny_spi
Signed-off-by: Thomas Chou <[email protected]> --- v2 minor cleanup, same as Grant suggest for spi_altera. v3 rename driver to spi_oc_tiny as Grant suggested. set version to tiny-spi-rtlsvn2 as Jonas suggested. v4 add dts binding doc. .../devicetree/bindings/spi/spi_oc_tiny.txt | 11 + drivers/spi/Kconfig | 6 + drivers/spi/Makefile | 1 + drivers/spi/spi_oc_tiny.c | 396 ++++++++++++++++++++ include/linux/spi/spi_oc_tiny.h | 14 + 5 files changed, 428 insertions(+), 0 deletions(-) create mode 100644 Documentation/devicetree/bindings/spi/spi_oc_tiny.txt create mode 100644 drivers/spi/spi_oc_tiny.c create mode 100644 include/linux/spi/spi_oc_tiny.h diff --git a/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt new file mode 100644 index 0000000..fba0f30 --- /dev/null +++ b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt @@ -0,0 +1,11 @@ +OpenCores tiny SPI + +Required properties: +- compatible : should be "opencores,tiny-spi-rtlsvn2". +Optional properties: +- clock-frequency : input clock frequency to the core. +- baud-width: width, in bits, of the programmable divider used to scale + the input clock to SCLK. + +The clock-frequency and baud-width properties are needed only if the divider +is programmable. They are not needed if the divider is fixed. diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index bb233a9..fbb82ee 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -231,6 +231,12 @@ config SPI_FSL_ESPI From MPC8536, 85xx platform uses the controller, and all P10xx, P20xx, P30xx,P40xx, P50xx uses this controller. +config SPI_OC_TINY + tristate "OpenCores tiny SPI" + select SPI_BITBANG + help + This is the driver for OpenCores tiny SPI master controller. + config SPI_OMAP_UWIRE tristate "OMAP1 MicroWire" depends on ARCH_OMAP1 diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 86d1b5f..c7e4c23 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -27,6 +27,7 @@ obj-$(CONFIG_SPI_IMX) += spi_imx.o obj-$(CONFIG_SPI_LM70_LLP) += spi_lm70llp.o obj-$(CONFIG_SPI_PXA2XX) += pxa2xx_spi.o obj-$(CONFIG_SPI_PXA2XX_PCI) += pxa2xx_spi_pci.o +obj-$(CONFIG_SPI_OC_TINY) += spi_oc_tiny.o obj-$(CONFIG_SPI_OMAP_UWIRE) += omap_uwire.o obj-$(CONFIG_SPI_OMAP24XX) += omap2_mcspi.o obj-$(CONFIG_SPI_OMAP_100K) += omap_spi_100k.o diff --git a/drivers/spi/spi_oc_tiny.c b/drivers/spi/spi_oc_tiny.c new file mode 100644 index 0000000..1ea3223 --- /dev/null +++ b/drivers/spi/spi_oc_tiny.c @@ -0,0 +1,396 @@ +/* + * OpenCores tiny SPI master driver + * + * http://opencores.org/project,tiny_spi + * + * Copyright (C) 2011 Thomas Chou <[email protected]> + * + * Based on spi_s3c24xx.c, which is: + * Copyright (c) 2006 Ben Dooks + * Copyright (c) 2006 Simtec Electronics + * Ben Dooks <[email protected]> + * + * 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 <linux/init.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/platform_device.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi_bitbang.h> +#include <linux/spi/spi_oc_tiny.h> +#include <linux/io.h> +#include <linux/gpio.h> +#include <linux/of.h> + +#define DRV_NAME "spi_oc_tiny" + +#define TINY_SPI_RXDATA 0 +#define TINY_SPI_TXDATA 4 +#define TINY_SPI_STATUS 8 +#define TINY_SPI_CONTROL 12 +#define TINY_SPI_BAUD 16 + +#define TINY_SPI_STATUS_TXE 0x1 +#define TINY_SPI_STATUS_TXR 0x2 + +struct tiny_spi { + /* bitbang has to be first */ + struct spi_bitbang bitbang; + struct completion done; + + void __iomem *base; + int irq; + unsigned int freq; + unsigned int baudwidth; + unsigned int baud; + unsigned int speed_hz; + unsigned int mode; + unsigned int len; + unsigned int txc, rxc; + const u8 *txp; + u8 *rxp; +}; + +static inline struct tiny_spi *tiny_spi_to_hw(struct spi_device *sdev) +{ + return spi_master_get_devdata(sdev->master); +} + +static unsigned int tiny_spi_baud(struct spi_device *spi, unsigned int hz) +{ + struct tiny_spi *hw = tiny_spi_to_hw(spi); + + return min(DIV_ROUND_UP(hw->freq, hz * 2), (1U << hw->baudwidth)) - 1; +} + +static void tiny_spi_chipselect(struct spi_device *spi, int is_active) +{ + gpio_set_value(spi->chip_select, + (spi->mode & SPI_CS_HIGH) ? is_active : !is_active); +} + +static int tiny_spi_setup_transfer(struct spi_device *spi, + struct spi_transfer *t) +{ + struct tiny_spi *hw = tiny_spi_to_hw(spi); + unsigned int baud = hw->baud; + + if (t) { + if (t->speed_hz && t->speed_hz != hw->speed_hz) + baud = tiny_spi_baud(spi, t->speed_hz); + } + writel(baud, hw->base + TINY_SPI_BAUD); + writel(hw->mode, hw->base + TINY_SPI_CONTROL); + return 0; +} + +static int tiny_spi_setup(struct spi_device *spi) +{ + struct tiny_spi *hw = tiny_spi_to_hw(spi); + + if (spi->max_speed_hz != hw->speed_hz) { + hw->speed_hz = spi->max_speed_hz; + hw->baud = tiny_spi_baud(spi, hw->speed_hz); + } + hw->mode = spi->mode & (SPI_CPOL | SPI_CPHA); + return 0; +} + +static int tiny_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) +{ + struct tiny_spi *hw = tiny_spi_to_hw(spi); + const u8 *txp = t->tx_buf; + u8 *rxp = t->rx_buf; + unsigned int i; + + if (hw->irq >= 0) { + /* use intrrupt driven data transfer */ + hw->len = t->len; + hw->txp = t->tx_buf; + hw->rxp = t->rx_buf; + hw->txc = 0; + hw->rxc = 0; + + /* send the first byte */ + if (t->len > 1) { + writeb(hw->txp ? *hw->txp++ : 0, + hw->base + TINY_SPI_TXDATA); + hw->txc++; + writeb(hw->txp ? *hw->txp++ : 0, + hw->base + TINY_SPI_TXDATA); + hw->txc++; + writeb(TINY_SPI_STATUS_TXR, hw->base + TINY_SPI_STATUS); + } else { + writeb(hw->txp ? *hw->txp++ : 0, + hw->base + TINY_SPI_TXDATA); + hw->txc++; + writeb(TINY_SPI_STATUS_TXE, hw->base + TINY_SPI_STATUS); + } + + wait_for_completion(&hw->done); + } else if (txp && rxp) { + /* we need to tighten the transfer loop */ + writeb(*txp++, hw->base + TINY_SPI_TXDATA); + if (t->len > 1) { + writeb(*txp++, hw->base + TINY_SPI_TXDATA); + for (i = 2; i < t->len; i++) { + u8 rx, tx = *txp++; + while (!(readb(hw->base + TINY_SPI_STATUS) & + TINY_SPI_STATUS_TXR)) + cpu_relax(); + rx = readb(hw->base + TINY_SPI_TXDATA); + writeb(tx, hw->base + TINY_SPI_TXDATA); + *rxp++ = rx; + } + while (!(readb(hw->base + TINY_SPI_STATUS) & + TINY_SPI_STATUS_TXR)) + cpu_relax(); + *rxp++ = readb(hw->base + TINY_SPI_TXDATA); + } + while (!(readb(hw->base + TINY_SPI_STATUS) & + TINY_SPI_STATUS_TXE)) + cpu_relax(); + *rxp++ = readb(hw->base + TINY_SPI_RXDATA); + } else if (rxp) { + writeb(0, hw->base + TINY_SPI_TXDATA); + if (t->len > 1) { + writeb(0, + hw->base + TINY_SPI_TXDATA); + for (i = 2; i < t->len; i++) { + u8 rx; + while (!(readb(hw->base + TINY_SPI_STATUS) & + TINY_SPI_STATUS_TXR)) + cpu_relax(); + rx = readb(hw->base + TINY_SPI_TXDATA); + writeb(0, + hw->base + TINY_SPI_TXDATA); + *rxp++ = rx; + } + while (!(readb(hw->base + TINY_SPI_STATUS) & + TINY_SPI_STATUS_TXR)) + cpu_relax(); + *rxp++ = readb(hw->base + TINY_SPI_TXDATA); + } + while (!(readb(hw->base + TINY_SPI_STATUS) & + TINY_SPI_STATUS_TXE)) + cpu_relax(); + *rxp++ = readb(hw->base + TINY_SPI_RXDATA); + } else if (txp) { + writeb(*txp++, hw->base + TINY_SPI_TXDATA); + if (t->len > 1) { + writeb(*txp++, hw->base + TINY_SPI_TXDATA); + for (i = 2; i < t->len; i++) { + u8 tx = *txp++; + while (!(readb(hw->base + TINY_SPI_STATUS) & + TINY_SPI_STATUS_TXR)) + cpu_relax(); + writeb(tx, hw->base + TINY_SPI_TXDATA); + } + } + while (!(readb(hw->base + TINY_SPI_STATUS) & + TINY_SPI_STATUS_TXE)) + cpu_relax(); + } else { + writeb(0, hw->base + TINY_SPI_TXDATA); + if (t->len > 1) { + writeb(0, + hw->base + TINY_SPI_TXDATA); + for (i = 2; i < t->len; i++) { + while (!(readb(hw->base + TINY_SPI_STATUS) & + TINY_SPI_STATUS_TXR)) + cpu_relax(); + writeb(0, + hw->base + TINY_SPI_TXDATA); + } + } + while (!(readb(hw->base + TINY_SPI_STATUS) & + TINY_SPI_STATUS_TXE)) + cpu_relax(); + } + return t->len; +} + +static irqreturn_t tiny_spi_irq(int irq, void *dev) +{ + struct tiny_spi *hw = dev; + + writeb(0, hw->base + TINY_SPI_STATUS); + if (hw->rxc + 1 == hw->len) { + if (hw->rxp) + *hw->rxp++ = readb(hw->base + TINY_SPI_RXDATA); + hw->rxc++; + complete(&hw->done); + } else { + if (hw->rxp) + *hw->rxp++ = readb(hw->base + TINY_SPI_TXDATA); + hw->rxc++; + if (hw->txc < hw->len) { + writeb(hw->txp ? *hw->txp++ : 0, + hw->base + TINY_SPI_TXDATA); + hw->txc++; + writeb(TINY_SPI_STATUS_TXR, + hw->base + TINY_SPI_STATUS); + } else { + writeb(TINY_SPI_STATUS_TXE, + hw->base + TINY_SPI_STATUS); + } + } + return IRQ_HANDLED; +} + +static int __devinit tiny_spi_probe(struct platform_device *pdev) +{ + struct tiny_spi_platform_data *platp = pdev->dev.platform_data; + struct tiny_spi *hw; + struct spi_master *master; + struct resource *res; + int err = 0; + + master = spi_alloc_master(&pdev->dev, sizeof(struct tiny_spi)); + if (master == NULL) { + dev_err(&pdev->dev, "No memory for spi_master\n"); + err = -ENOMEM; + goto err_no_mem; + } + + /* setup the master state. */ + master->bus_num = pdev->id; + master->num_chipselect = 255; + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; + master->setup = tiny_spi_setup; + + hw = spi_master_get_devdata(master); + platform_set_drvdata(pdev, hw); + + /* setup the state for the bitbang driver */ + hw->bitbang.master = spi_master_get(master); + if (hw->bitbang.master == NULL) { + dev_err(&pdev->dev, "Cannot get device\n"); + err = -ENODEV; + goto err_no_dev; + } + hw->bitbang.setup_transfer = tiny_spi_setup_transfer; + hw->bitbang.chipselect = tiny_spi_chipselect; + hw->bitbang.txrx_bufs = tiny_spi_txrx_bufs; + + /* find and map our resources */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (res == NULL) { + dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n"); + err = -ENOENT; + goto err_no_iores; + } + hw->base = ioremap(res->start, (res->end - res->start) + 1); + if (hw->base == 0) { + dev_err(&pdev->dev, "Cannot map IO\n"); + err = -ENXIO; + goto err_no_iomap; + } + /* irq is optional */ + hw->irq = platform_get_irq(pdev, 0); + if (hw->irq >= 0) { + init_completion(&hw->done); + err = request_irq(hw->irq, tiny_spi_irq, 0, pdev->name, hw); + if (err) { + dev_err(&pdev->dev, "Cannot claim IRQ\n"); + goto err_no_irq; + } + } + /* find platform data */ + if (platp) { + hw->freq = platp->freq; + hw->baudwidth = platp->baudwidth; + } else { +#ifdef CONFIG_OF + const __be32 *val; + + hw->bitbang.master->dev.of_node = pdev->dev.of_node; + val = of_get_property(pdev->dev.of_node, + "clock-frequency", NULL); + if (val) + hw->freq = be32_to_cpup(val); + val = of_get_property(pdev->dev.of_node, "baud-width", NULL); + if (val) + hw->baudwidth = be32_to_cpup(val); +#endif + } + + /* register our spi controller */ + err = spi_bitbang_start(&hw->bitbang); + if (err) { + dev_err(&pdev->dev, "Failed to register SPI master\n"); + goto err_register; + } + dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq); + + return 0; + +err_register: + if (hw->irq >= 0) + free_irq(hw->irq, hw); +err_no_irq: + iounmap(hw->base); +err_no_iomap: +err_no_iores: + spi_master_put(master); +err_no_mem: +err_no_dev: + return err; +} + +static int __devexit tiny_spi_remove(struct platform_device *dev) +{ + struct tiny_spi *hw = platform_get_drvdata(dev); + struct spi_master *master = hw->bitbang.master; + + spi_bitbang_stop(&hw->bitbang); + + if (hw->irq >= 0) + free_irq(hw->irq, hw); + iounmap(hw->base); + + platform_set_drvdata(dev, NULL); + spi_master_put(master); + return 0; +} + +static const struct of_device_id tiny_spi_match[] = { + { .compatible = "opencores,tiny-spi-rtlsvn2", }, + {}, +} +MODULE_DEVICE_TABLE(of, tiny_spi_match); + +static struct platform_driver tiny_spidrv = { + .remove = __devexit_p(tiny_spi_remove), + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + .pm = NULL, + .of_match_table = tiny_spi_match, + }, +}; + +static int __init tiny_spi_init(void) +{ + return platform_driver_probe(&tiny_spidrv, tiny_spi_probe); +} +module_init(tiny_spi_init); + +static void __exit tiny_spi_exit(void) +{ + platform_driver_unregister(&tiny_spidrv); +} +module_exit(tiny_spi_exit); + +MODULE_DESCRIPTION("OpenCores tiny SPI driver"); +MODULE_AUTHOR("Thomas Chou <[email protected]>"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" DRV_NAME); diff --git a/include/linux/spi/spi_oc_tiny.h b/include/linux/spi/spi_oc_tiny.h new file mode 100644 index 0000000..5080e1c --- /dev/null +++ b/include/linux/spi/spi_oc_tiny.h @@ -0,0 +1,14 @@ +#ifndef _LINUX_SPI_SPI_OC_TINY_H +#define _LINUX_SPI_SPI_OC_TINY_H + +/* + * struct tiny_spi_platform_data - platform data of the OpenCores tiny SPI + * @freq: input clock freq to the core. + * @baudwidth: baud rate divider width of the core. + */ +struct tiny_spi_platform_data { + uint freq; + uint baudwidth; +}; + +#endif /* _LINUX_SPI_SPI_OC_TINY_H */ -- 1.7.3.5 _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
