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    SubjectRe: [PATCH v9] spi: New driver for Altera SPI
    On Mon, Feb 14, 2011 at 10:10:43AM +0800, Thomas Chou wrote:
    > This patch adds a new SPI driver to support the Altera SOPC Builder
    > SPI component. It uses the bitbanging library.
    >
    > Signed-off-by: Thomas Chou <thomas@wytron.com.tw>

    Applied, thanks.

    g.

    > ---
    > v2 add devicetree support
    > v3 remove platform header, as Grant suggested.
    > no irq resource means polling.
    > v4 minor cleanup, as Grant suggested.
    > v5 add compat version.
    > v6 change compatible vendor to uppercase, ALTR.
    > add dts binding doc.
    > v7 use platform driver register.
    > use devm_ to help cleanup.
    > v8 remove default n in Kconfig.
    > v9 condition module device table export for of.
    >
    > .../devicetree/bindings/spi/spi_altera.txt | 4 +
    > drivers/spi/Kconfig | 6 +
    > drivers/spi/Makefile | 1 +
    > drivers/spi/spi_altera.c | 339 ++++++++++++++++++++
    > 4 files changed, 350 insertions(+), 0 deletions(-)
    > create mode 100644 Documentation/devicetree/bindings/spi/spi_altera.txt
    > create mode 100644 drivers/spi/spi_altera.c
    >
    > diff --git a/Documentation/devicetree/bindings/spi/spi_altera.txt b/Documentation/devicetree/bindings/spi/spi_altera.txt
    > new file mode 100644
    > index 0000000..dda3759
    > --- /dev/null
    > +++ b/Documentation/devicetree/bindings/spi/spi_altera.txt
    > @@ -0,0 +1,4 @@
    > +Altera SPI
    > +
    > +Required properties:
    > +- compatible : should be "ALTR,spi-1.0".
    > diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
    > index bb233a9..e791579 100644
    > --- a/drivers/spi/Kconfig
    > +++ b/drivers/spi/Kconfig
    > @@ -53,6 +53,12 @@ if SPI_MASTER
    >
    > comment "SPI Master Controller Drivers"
    >
    > +config SPI_ALTERA
    > + tristate "Altera SPI Controller"
    > + select SPI_BITBANG
    > + help
    > + This is the driver for the Altera SPI Controller.
    > +
    > config SPI_ATH79
    > tristate "Atheros AR71XX/AR724X/AR913X SPI controller driver"
    > depends on ATH79 && GENERIC_GPIO
    > diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
    > index 86d1b5f..4d2e35a 100644
    > --- a/drivers/spi/Makefile
    > +++ b/drivers/spi/Makefile
    > @@ -9,6 +9,7 @@ ccflags-$(CONFIG_SPI_DEBUG) := -DDEBUG
    > obj-$(CONFIG_SPI_MASTER) += spi.o
    >
    > # SPI master controller drivers (bus)
    > +obj-$(CONFIG_SPI_ALTERA) += spi_altera.o
    > obj-$(CONFIG_SPI_ATMEL) += atmel_spi.o
    > obj-$(CONFIG_SPI_ATH79) += ath79_spi.o
    > obj-$(CONFIG_SPI_BFIN) += spi_bfin5xx.o
    > diff --git a/drivers/spi/spi_altera.c b/drivers/spi/spi_altera.c
    > new file mode 100644
    > index 0000000..5e001f3
    > --- /dev/null
    > +++ b/drivers/spi/spi_altera.c
    > @@ -0,0 +1,339 @@
    > +/*
    > + * Altera SPI driver
    > + *
    > + * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
    > + *
    > + * Based on spi_s3c24xx.c, which is:
    > + * Copyright (c) 2006 Ben Dooks
    > + * Copyright (c) 2006 Simtec Electronics
    > + * Ben Dooks <ben@simtec.co.uk>
    > + *
    > + * 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/interrupt.h>
    > +#include <linux/errno.h>
    > +#include <linux/platform_device.h>
    > +#include <linux/spi/spi.h>
    > +#include <linux/spi/spi_bitbang.h>
    > +#include <linux/io.h>
    > +#include <linux/of.h>
    > +
    > +#define DRV_NAME "spi_altera"
    > +
    > +#define ALTERA_SPI_RXDATA 0
    > +#define ALTERA_SPI_TXDATA 4
    > +#define ALTERA_SPI_STATUS 8
    > +#define ALTERA_SPI_CONTROL 12
    > +#define ALTERA_SPI_SLAVE_SEL 20
    > +
    > +#define ALTERA_SPI_STATUS_ROE_MSK 0x8
    > +#define ALTERA_SPI_STATUS_TOE_MSK 0x10
    > +#define ALTERA_SPI_STATUS_TMT_MSK 0x20
    > +#define ALTERA_SPI_STATUS_TRDY_MSK 0x40
    > +#define ALTERA_SPI_STATUS_RRDY_MSK 0x80
    > +#define ALTERA_SPI_STATUS_E_MSK 0x100
    > +
    > +#define ALTERA_SPI_CONTROL_IROE_MSK 0x8
    > +#define ALTERA_SPI_CONTROL_ITOE_MSK 0x10
    > +#define ALTERA_SPI_CONTROL_ITRDY_MSK 0x40
    > +#define ALTERA_SPI_CONTROL_IRRDY_MSK 0x80
    > +#define ALTERA_SPI_CONTROL_IE_MSK 0x100
    > +#define ALTERA_SPI_CONTROL_SSO_MSK 0x400
    > +
    > +struct altera_spi {
    > + /* bitbang has to be first */
    > + struct spi_bitbang bitbang;
    > + struct completion done;
    > +
    > + void __iomem *base;
    > + int irq;
    > + int len;
    > + int count;
    > + int bytes_per_word;
    > + unsigned long imr;
    > +
    > + /* data buffers */
    > + const unsigned char *tx;
    > + unsigned char *rx;
    > +};
    > +
    > +static inline struct altera_spi *altera_spi_to_hw(struct spi_device *sdev)
    > +{
    > + return spi_master_get_devdata(sdev->master);
    > +}
    > +
    > +static void altera_spi_chipsel(struct spi_device *spi, int value)
    > +{
    > + struct altera_spi *hw = altera_spi_to_hw(spi);
    > +
    > + if (spi->mode & SPI_CS_HIGH) {
    > + switch (value) {
    > + case BITBANG_CS_INACTIVE:
    > + writel(1 << spi->chip_select,
    > + hw->base + ALTERA_SPI_SLAVE_SEL);
    > + hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
    > + writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
    > + break;
    > +
    > + case BITBANG_CS_ACTIVE:
    > + hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
    > + writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
    > + writel(0, hw->base + ALTERA_SPI_SLAVE_SEL);
    > + break;
    > + }
    > + } else {
    > + switch (value) {
    > + case BITBANG_CS_INACTIVE:
    > + hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
    > + writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
    > + break;
    > +
    > + case BITBANG_CS_ACTIVE:
    > + writel(1 << spi->chip_select,
    > + hw->base + ALTERA_SPI_SLAVE_SEL);
    > + hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
    > + writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
    > + break;
    > + }
    > + }
    > +}
    > +
    > +static int altera_spi_setupxfer(struct spi_device *spi, struct spi_transfer *t)
    > +{
    > + return 0;
    > +}
    > +
    > +static int altera_spi_setup(struct spi_device *spi)
    > +{
    > + return 0;
    > +}
    > +
    > +static inline unsigned int hw_txbyte(struct altera_spi *hw, int count)
    > +{
    > + if (hw->tx) {
    > + switch (hw->bytes_per_word) {
    > + case 1:
    > + return hw->tx[count];
    > + case 2:
    > + return (hw->tx[count * 2]
    > + | (hw->tx[count * 2 + 1] << 8));
    > + }
    > + }
    > + return 0;
    > +}
    > +
    > +static int altera_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
    > +{
    > + struct altera_spi *hw = altera_spi_to_hw(spi);
    > +
    > + hw->tx = t->tx_buf;
    > + hw->rx = t->rx_buf;
    > + hw->count = 0;
    > + hw->bytes_per_word = (t->bits_per_word ? : spi->bits_per_word) / 8;
    > + hw->len = t->len / hw->bytes_per_word;
    > +
    > + if (hw->irq >= 0) {
    > + /* enable receive interrupt */
    > + hw->imr |= ALTERA_SPI_CONTROL_IRRDY_MSK;
    > + writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
    > +
    > + /* send the first byte */
    > + writel(hw_txbyte(hw, 0), hw->base + ALTERA_SPI_TXDATA);
    > +
    > + wait_for_completion(&hw->done);
    > + /* disable receive interrupt */
    > + hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
    > + writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
    > + } else {
    > + /* send the first byte */
    > + writel(hw_txbyte(hw, 0), hw->base + ALTERA_SPI_TXDATA);
    > +
    > + while (1) {
    > + unsigned int rxd;
    > +
    > + while (!(readl(hw->base + ALTERA_SPI_STATUS) &
    > + ALTERA_SPI_STATUS_RRDY_MSK))
    > + cpu_relax();
    > +
    > + rxd = readl(hw->base + ALTERA_SPI_RXDATA);
    > + if (hw->rx) {
    > + switch (hw->bytes_per_word) {
    > + case 1:
    > + hw->rx[hw->count] = rxd;
    > + break;
    > + case 2:
    > + hw->rx[hw->count * 2] = rxd;
    > + hw->rx[hw->count * 2 + 1] = rxd >> 8;
    > + break;
    > + }
    > + }
    > +
    > + hw->count++;
    > +
    > + if (hw->count < hw->len)
    > + writel(hw_txbyte(hw, hw->count),
    > + hw->base + ALTERA_SPI_TXDATA);
    > + else
    > + break;
    > + }
    > +
    > + }
    > +
    > + return hw->count * hw->bytes_per_word;
    > +}
    > +
    > +static irqreturn_t altera_spi_irq(int irq, void *dev)
    > +{
    > + struct altera_spi *hw = dev;
    > + unsigned int rxd;
    > +
    > + rxd = readl(hw->base + ALTERA_SPI_RXDATA);
    > + if (hw->rx) {
    > + switch (hw->bytes_per_word) {
    > + case 1:
    > + hw->rx[hw->count] = rxd;
    > + break;
    > + case 2:
    > + hw->rx[hw->count * 2] = rxd;
    > + hw->rx[hw->count * 2 + 1] = rxd >> 8;
    > + break;
    > + }
    > + }
    > +
    > + hw->count++;
    > +
    > + if (hw->count < hw->len)
    > + writel(hw_txbyte(hw, hw->count), hw->base + ALTERA_SPI_TXDATA);
    > + else
    > + complete(&hw->done);
    > +
    > + return IRQ_HANDLED;
    > +}
    > +
    > +static int __devinit altera_spi_probe(struct platform_device *pdev)
    > +{
    > + struct altera_spi_platform_data *platp = pdev->dev.platform_data;
    > + struct altera_spi *hw;
    > + struct spi_master *master;
    > + struct resource *res;
    > + int err = -ENODEV;
    > +
    > + master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
    > + if (!master)
    > + return err;
    > +
    > + /* setup the master state. */
    > + master->bus_num = pdev->id;
    > + master->num_chipselect = 16;
    > + master->mode_bits = SPI_CS_HIGH;
    > + master->setup = altera_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)
    > + return err;
    > + hw->bitbang.setup_transfer = altera_spi_setupxfer;
    > + hw->bitbang.chipselect = altera_spi_chipsel;
    > + hw->bitbang.txrx_bufs = altera_spi_txrx;
    > +
    > + /* find and map our resources */
    > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    > + if (!res)
    > + goto exit_busy;
    > + if (!devm_request_mem_region(&pdev->dev, res->start, resource_size(res),
    > + pdev->name))
    > + goto exit_busy;
    > + hw->base = devm_ioremap_nocache(&pdev->dev, res->start,
    > + resource_size(res));
    > + if (!hw->base)
    > + goto exit_busy;
    > + /* program defaults into the registers */
    > + hw->imr = 0; /* disable spi interrupts */
    > + writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
    > + writel(0, hw->base + ALTERA_SPI_STATUS); /* clear status reg */
    > + if (readl(hw->base + ALTERA_SPI_STATUS) & ALTERA_SPI_STATUS_RRDY_MSK)
    > + readl(hw->base + ALTERA_SPI_RXDATA); /* flush rxdata */
    > + /* irq is optional */
    > + hw->irq = platform_get_irq(pdev, 0);
    > + if (hw->irq >= 0) {
    > + init_completion(&hw->done);
    > + err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0,
    > + pdev->name, hw);
    > + if (err)
    > + goto exit;
    > + }
    > + /* find platform data */
    > + if (!platp)
    > + hw->bitbang.master->dev.of_node = pdev->dev.of_node;
    > +
    > + /* register our spi controller */
    > + err = spi_bitbang_start(&hw->bitbang);
    > + if (err)
    > + goto exit;
    > + dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
    > +
    > + return 0;
    > +
    > +exit_busy:
    > + err = -EBUSY;
    > +exit:
    > + platform_set_drvdata(pdev, NULL);
    > + spi_master_put(master);
    > + return err;
    > +}
    > +
    > +static int __devexit altera_spi_remove(struct platform_device *dev)
    > +{
    > + struct altera_spi *hw = platform_get_drvdata(dev);
    > + struct spi_master *master = hw->bitbang.master;
    > +
    > + spi_bitbang_stop(&hw->bitbang);
    > + platform_set_drvdata(dev, NULL);
    > + spi_master_put(master);
    > + return 0;
    > +}
    > +
    > +#ifdef CONFIG_OF
    > +static const struct of_device_id altera_spi_match[] = {
    > + { .compatible = "ALTR,spi-1.0", },
    > + {},
    > +}
    > +MODULE_DEVICE_TABLE(of, altera_spi_match);
    > +#else /* CONFIG_OF */
    > +#define altera_spi_match NULL
    > +#endif /* CONFIG_OF */
    > +
    > +static struct platform_driver altera_spi_driver = {
    > + .probe = altera_spi_probe,
    > + .remove = __devexit_p(altera_spi_remove),
    > + .driver = {
    > + .name = DRV_NAME,
    > + .owner = THIS_MODULE,
    > + .pm = NULL,
    > + .of_match_table = altera_spi_match,
    > + },
    > +};
    > +
    > +static int __init altera_spi_init(void)
    > +{
    > + return platform_driver_register(&altera_spi_driver);
    > +}
    > +module_init(altera_spi_init);
    > +
    > +static void __exit altera_spi_exit(void)
    > +{
    > + platform_driver_unregister(&altera_spi_driver);
    > +}
    > +module_exit(altera_spi_exit);
    > +
    > +MODULE_DESCRIPTION("Altera SPI driver");
    > +MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
    > +MODULE_LICENSE("GPL");
    > +MODULE_ALIAS("platform:" DRV_NAME);
    > --
    > 1.7.4
    >


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