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openwrt/target/linux/brcm2708/patches-3.10/009-bcm2708-spi-driver.patch

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--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -86,6 +86,14 @@ config SPI_BCM2835
is for the regular SPI controller. Slave mode operation is not also
not supported.
+config SPI_BCM2708
+ tristate "BCM2708 SPI controller driver (SPI0)"
+ depends on MACH_BCM2708
+ help
+ This selects a driver for the Broadcom BCM2708 SPI master (SPI0). This
+ driver is not compatible with the "Universal SPI Master" or the SPI slave
+ device.
+
config SPI_BFIN5XX
tristate "SPI controller driver for ADI Blackfin5xx"
depends on BLACKFIN
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_SPI_AU1550) += spi-au1550.
obj-$(CONFIG_SPI_BCM2835) += spi-bcm2835.o
obj-$(CONFIG_SPI_BCM63XX) += spi-bcm63xx.o
obj-$(CONFIG_SPI_BFIN5XX) += spi-bfin5xx.o
+obj-$(CONFIG_SPI_BCM2708) += spi-bcm2708.o
obj-$(CONFIG_SPI_BFIN_SPORT) += spi-bfin-sport.o
obj-$(CONFIG_SPI_BITBANG) += spi-bitbang.o
obj-$(CONFIG_SPI_BUTTERFLY) += spi-butterfly.o
--- /dev/null
+++ b/drivers/spi/spi-bcm2708.c
@@ -0,0 +1,626 @@
+/*
+ * Driver for Broadcom BCM2708 SPI Controllers
+ *
+ * Copyright (C) 2012 Chris Boot
+ *
+ * This driver is inspired by:
+ * spi-ath79.c, Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
+ * spi-atmel.c, Copyright (C) 2006 Atmel Corporation
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/spi/spi.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/log2.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+/* SPI register offsets */
+#define SPI_CS 0x00
+#define SPI_FIFO 0x04
+#define SPI_CLK 0x08
+#define SPI_DLEN 0x0c
+#define SPI_LTOH 0x10
+#define SPI_DC 0x14
+
+/* Bitfields in CS */
+#define SPI_CS_LEN_LONG 0x02000000
+#define SPI_CS_DMA_LEN 0x01000000
+#define SPI_CS_CSPOL2 0x00800000
+#define SPI_CS_CSPOL1 0x00400000
+#define SPI_CS_CSPOL0 0x00200000
+#define SPI_CS_RXF 0x00100000
+#define SPI_CS_RXR 0x00080000
+#define SPI_CS_TXD 0x00040000
+#define SPI_CS_RXD 0x00020000
+#define SPI_CS_DONE 0x00010000
+#define SPI_CS_LEN 0x00002000
+#define SPI_CS_REN 0x00001000
+#define SPI_CS_ADCS 0x00000800
+#define SPI_CS_INTR 0x00000400
+#define SPI_CS_INTD 0x00000200
+#define SPI_CS_DMAEN 0x00000100
+#define SPI_CS_TA 0x00000080
+#define SPI_CS_CSPOL 0x00000040
+#define SPI_CS_CLEAR_RX 0x00000020
+#define SPI_CS_CLEAR_TX 0x00000010
+#define SPI_CS_CPOL 0x00000008
+#define SPI_CS_CPHA 0x00000004
+#define SPI_CS_CS_10 0x00000002
+#define SPI_CS_CS_01 0x00000001
+
+#define SPI_TIMEOUT_MS 150
+
+#define DRV_NAME "bcm2708_spi"
+
+struct bcm2708_spi {
+ spinlock_t lock;
+ void __iomem *base;
+ int irq;
+ struct clk *clk;
+ bool stopping;
+
+ struct list_head queue;
+ struct workqueue_struct *workq;
+ struct work_struct work;
+ struct completion done;
+
+ const u8 *tx_buf;
+ u8 *rx_buf;
+ int len;
+};
+
+struct bcm2708_spi_state {
+ u32 cs;
+ u16 cdiv;
+};
+
+/*
+ * This function sets the ALT mode on the SPI pins so that we can use them with
+ * the SPI hardware.
+ *
+ * FIXME: This is a hack. Use pinmux / pinctrl.
+ */
+static void bcm2708_init_pinmode(void)
+{
+#define INP_GPIO(g) *(gpio+((g)/10)) &= ~(7<<(((g)%10)*3))
+#define SET_GPIO_ALT(g,a) *(gpio+(((g)/10))) |= (((a)<=3?(a)+4:(a)==4?3:2)<<(((g)%10)*3))
+
+ int pin;
+ u32 *gpio = ioremap(0x20200000, SZ_16K);
+
+ /* SPI is on GPIO 7..11 */
+ for (pin = 7; pin <= 11; pin++) {
+ INP_GPIO(pin); /* set mode to GPIO input first */
+ SET_GPIO_ALT(pin, 0); /* set mode to ALT 0 */
+ }
+
+ iounmap(gpio);
+
+#undef INP_GPIO
+#undef SET_GPIO_ALT
+}
+
+static inline u32 bcm2708_rd(struct bcm2708_spi *bs, unsigned reg)
+{
+ return readl(bs->base + reg);
+}
+
+static inline void bcm2708_wr(struct bcm2708_spi *bs, unsigned reg, u32 val)
+{
+ writel(val, bs->base + reg);
+}
+
+static inline void bcm2708_rd_fifo(struct bcm2708_spi *bs, int len)
+{
+ u8 byte;
+
+ while (len--) {
+ byte = bcm2708_rd(bs, SPI_FIFO);
+ if (bs->rx_buf)
+ *bs->rx_buf++ = byte;
+ }
+}
+
+static inline void bcm2708_wr_fifo(struct bcm2708_spi *bs, int len)
+{
+ u8 byte;
+ u16 val;
+
+ if (len > bs->len)
+ len = bs->len;
+
+ if (unlikely(bcm2708_rd(bs, SPI_CS) & SPI_CS_LEN)) {
+ /* LoSSI mode */
+ if (unlikely(len % 2)) {
+ printk(KERN_ERR"bcm2708_wr_fifo: length must be even, skipping.\n");
+ bs->len = 0;
+ return;
+ }
+ while (len) {
+ if (bs->tx_buf) {
+ val = *(const u16 *)bs->tx_buf;
+ bs->tx_buf += 2;
+ } else
+ val = 0;
+ bcm2708_wr(bs, SPI_FIFO, val);
+ bs->len -= 2;
+ len -= 2;
+ }
+ return;
+ }
+
+ while (len--) {
+ byte = bs->tx_buf ? *bs->tx_buf++ : 0;
+ bcm2708_wr(bs, SPI_FIFO, byte);
+ bs->len--;
+ }
+}
+
+static irqreturn_t bcm2708_spi_interrupt(int irq, void *dev_id)
+{
+ struct spi_master *master = dev_id;
+ struct bcm2708_spi *bs = spi_master_get_devdata(master);
+ u32 cs;
+
+ spin_lock(&bs->lock);
+
+ cs = bcm2708_rd(bs, SPI_CS);
+
+ if (cs & SPI_CS_DONE) {
+ if (bs->len) { /* first interrupt in a transfer */
+ /* fill the TX fifo with up to 16 bytes */
+ bcm2708_wr_fifo(bs, 16);
+ } else { /* transfer complete */
+ /* disable interrupts */
+ cs &= ~(SPI_CS_INTR | SPI_CS_INTD);
+ bcm2708_wr(bs, SPI_CS, cs);
+
+ /* drain RX FIFO */
+ while (cs & SPI_CS_RXD) {
+ bcm2708_rd_fifo(bs, 1);
+ cs = bcm2708_rd(bs, SPI_CS);
+ }
+
+ /* wake up our bh */
+ complete(&bs->done);
+ }
+ } else if (cs & SPI_CS_RXR) {
+ /* read 12 bytes of data */
+ bcm2708_rd_fifo(bs, 12);
+
+ /* write up to 12 bytes */
+ bcm2708_wr_fifo(bs, 12);
+ }
+
+ spin_unlock(&bs->lock);
+
+ return IRQ_HANDLED;
+}
+
+static int bcm2708_setup_state(struct spi_master *master,
+ struct device *dev, struct bcm2708_spi_state *state,
+ u32 hz, u8 csel, u8 mode, u8 bpw)
+{
+ struct bcm2708_spi *bs = spi_master_get_devdata(master);
+ int cdiv;
+ unsigned long bus_hz;
+ u32 cs = 0;
+
+ bus_hz = clk_get_rate(bs->clk);
+
+ if (hz >= bus_hz) {
+ cdiv = 2; /* bus_hz / 2 is as fast as we can go */
+ } else if (hz) {
+ cdiv = DIV_ROUND_UP(bus_hz, hz);
+
+ /* CDIV must be a power of 2, so round up */
+ cdiv = roundup_pow_of_two(cdiv);
+
+ if (cdiv > 65536) {
+ dev_dbg(dev,
+ "setup: %d Hz too slow, cdiv %u; min %ld Hz\n",
+ hz, cdiv, bus_hz / 65536);
+ return -EINVAL;
+ } else if (cdiv == 65536) {
+ cdiv = 0;
+ } else if (cdiv == 1) {
+ cdiv = 2; /* 1 gets rounded down to 0; == 65536 */
+ }
+ } else {
+ cdiv = 0;
+ }
+
+ switch (bpw) {
+ case 8:
+ break;
+ case 9:
+ /* Reading in LoSSI mode is a special case. See 'BCM2835 ARM Peripherals' datasheet */
+ cs |= SPI_CS_LEN;
+ break;
+ default:
+ dev_dbg(dev, "setup: invalid bits_per_word %u (must be 8 or 9)\n",
+ bpw);
+ return -EINVAL;
+ }
+
+ if (mode & SPI_CPOL)
+ cs |= SPI_CS_CPOL;
+ if (mode & SPI_CPHA)
+ cs |= SPI_CS_CPHA;
+
+ if (!(mode & SPI_NO_CS)) {
+ if (mode & SPI_CS_HIGH) {
+ cs |= SPI_CS_CSPOL;
+ cs |= SPI_CS_CSPOL0 << csel;
+ }
+
+ cs |= csel;
+ } else {
+ cs |= SPI_CS_CS_10 | SPI_CS_CS_01;
+ }
+
+ if (state) {
+ state->cs = cs;
+ state->cdiv = cdiv;
+ dev_dbg(dev, "setup: want %d Hz; "
+ "bus_hz=%lu / cdiv=%u == %lu Hz; "
+ "mode %u: cs 0x%08X\n",
+ hz, bus_hz, cdiv, bus_hz/cdiv, mode, cs);
+ }
+
+ return 0;
+}
+
+static int bcm2708_process_transfer(struct bcm2708_spi *bs,
+ struct spi_message *msg, struct spi_transfer *xfer)
+{
+ struct spi_device *spi = msg->spi;
+ struct bcm2708_spi_state state, *stp;
+ int ret;
+ u32 cs;
+
+ if (bs->stopping)
+ return -ESHUTDOWN;
+
+ if (xfer->bits_per_word || xfer->speed_hz) {
+ ret = bcm2708_setup_state(spi->master, &spi->dev, &state,
+ xfer->speed_hz ? xfer->speed_hz : spi->max_speed_hz,
+ spi->chip_select, spi->mode,
+ xfer->bits_per_word ? xfer->bits_per_word :
+ spi->bits_per_word);
+ if (ret)
+ return ret;
+
+ stp = &state;
+ } else {
+ stp = spi->controller_state;
+ }
+
+ INIT_COMPLETION(bs->done);
+ bs->tx_buf = xfer->tx_buf;
+ bs->rx_buf = xfer->rx_buf;
+ bs->len = xfer->len;
+
+ cs = stp->cs | SPI_CS_INTR | SPI_CS_INTD | SPI_CS_TA;
+
+ bcm2708_wr(bs, SPI_CLK, stp->cdiv);
+ bcm2708_wr(bs, SPI_CS, cs);
+
+ ret = wait_for_completion_timeout(&bs->done,
+ msecs_to_jiffies(SPI_TIMEOUT_MS));
+ if (ret == 0) {
+ dev_err(&spi->dev, "transfer timed out\n");
+ return -ETIMEDOUT;
+ }
+
+ if (xfer->delay_usecs)
+ udelay(xfer->delay_usecs);
+
+ if (list_is_last(&xfer->transfer_list, &msg->transfers) ||
+ xfer->cs_change) {
+ /* clear TA and interrupt flags */
+ bcm2708_wr(bs, SPI_CS, stp->cs);
+ }
+
+ msg->actual_length += (xfer->len - bs->len);
+
+ return 0;
+}
+
+static void bcm2708_work(struct work_struct *work)
+{
+ struct bcm2708_spi *bs = container_of(work, struct bcm2708_spi, work);
+ unsigned long flags;
+ struct spi_message *msg;
+ struct spi_transfer *xfer;
+ int status = 0;
+
+ spin_lock_irqsave(&bs->lock, flags);
+ while (!list_empty(&bs->queue)) {
+ msg = list_first_entry(&bs->queue, struct spi_message, queue);
+ list_del_init(&msg->queue);
+ spin_unlock_irqrestore(&bs->lock, flags);
+
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ status = bcm2708_process_transfer(bs, msg, xfer);
+ if (status)
+ break;
+ }
+
+ msg->status = status;
+ msg->complete(msg->context);
+
+ spin_lock_irqsave(&bs->lock, flags);
+ }
+ spin_unlock_irqrestore(&bs->lock, flags);
+}
+
+static int bcm2708_spi_setup(struct spi_device *spi)
+{
+ struct bcm2708_spi *bs = spi_master_get_devdata(spi->master);
+ struct bcm2708_spi_state *state;
+ int ret;
+
+ if (bs->stopping)
+ return -ESHUTDOWN;
+
+ if (!(spi->mode & SPI_NO_CS) &&
+ (spi->chip_select > spi->master->num_chipselect)) {
+ dev_dbg(&spi->dev,
+ "setup: invalid chipselect %u (%u defined)\n",
+ spi->chip_select, spi->master->num_chipselect);
+ return -EINVAL;
+ }
+
+ state = spi->controller_state;
+ if (!state) {
+ state = kzalloc(sizeof(*state), GFP_KERNEL);
+ if (!state)
+ return -ENOMEM;
+
+ spi->controller_state = state;
+ }
+
+ ret = bcm2708_setup_state(spi->master, &spi->dev, state,
+ spi->max_speed_hz, spi->chip_select, spi->mode,
+ spi->bits_per_word);
+ if (ret < 0) {
+ kfree(state);
+ spi->controller_state = NULL;
+ return ret;
+ }
+
+ dev_dbg(&spi->dev,
+ "setup: cd %d: %d Hz, bpw %u, mode 0x%x -> CS=%08x CDIV=%04x\n",
+ spi->chip_select, spi->max_speed_hz, spi->bits_per_word,
+ spi->mode, state->cs, state->cdiv);
+
+ return 0;
+}
+
+static int bcm2708_spi_transfer(struct spi_device *spi, struct spi_message *msg)
+{
+ struct bcm2708_spi *bs = spi_master_get_devdata(spi->master);
+ struct spi_transfer *xfer;
+ int ret;
+ unsigned long flags;
+
+ if (unlikely(list_empty(&msg->transfers)))
+ return -EINVAL;
+
+ if (bs->stopping)
+ return -ESHUTDOWN;
+
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ if (!(xfer->tx_buf || xfer->rx_buf) && xfer->len) {
+ dev_dbg(&spi->dev, "missing rx or tx buf\n");
+ return -EINVAL;
+ }
+
+ if (!xfer->bits_per_word || xfer->speed_hz)
+ continue;
+
+ ret = bcm2708_setup_state(spi->master, &spi->dev, NULL,
+ xfer->speed_hz ? xfer->speed_hz : spi->max_speed_hz,
+ spi->chip_select, spi->mode,
+ xfer->bits_per_word ? xfer->bits_per_word :
+ spi->bits_per_word);
+ if (ret)
+ return ret;
+ }
+
+ msg->status = -EINPROGRESS;
+ msg->actual_length = 0;
+
+ spin_lock_irqsave(&bs->lock, flags);
+ list_add_tail(&msg->queue, &bs->queue);
+ queue_work(bs->workq, &bs->work);
+ spin_unlock_irqrestore(&bs->lock, flags);
+
+ return 0;
+}
+
+static void bcm2708_spi_cleanup(struct spi_device *spi)
+{
+ if (spi->controller_state) {
+ kfree(spi->controller_state);
+ spi->controller_state = NULL;
+ }
+}
+
+static int bcm2708_spi_probe(struct platform_device *pdev)
+{
+ struct resource *regs;
+ int irq, err = -ENOMEM;
+ struct clk *clk;
+ struct spi_master *master;
+ struct bcm2708_spi *bs;
+
+ regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!regs) {
+ dev_err(&pdev->dev, "could not get IO memory\n");
+ return -ENXIO;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "could not get IRQ\n");
+ return irq;
+ }
+
+ clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "could not find clk: %ld\n", PTR_ERR(clk));
+ return PTR_ERR(clk);
+ }
+
+ bcm2708_init_pinmode();
+
+ master = spi_alloc_master(&pdev->dev, sizeof(*bs));
+ if (!master) {
+ dev_err(&pdev->dev, "spi_alloc_master() failed\n");
+ goto out_clk_put;
+ }
+
+ /* the spi->mode bits understood by this driver: */
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_NO_CS;
+
+ master->bus_num = pdev->id;
+ master->num_chipselect = 3;
+ master->setup = bcm2708_spi_setup;
+ master->transfer = bcm2708_spi_transfer;
+ master->cleanup = bcm2708_spi_cleanup;
+ platform_set_drvdata(pdev, master);
+
+ bs = spi_master_get_devdata(master);
+
+ spin_lock_init(&bs->lock);
+ INIT_LIST_HEAD(&bs->queue);
+ init_completion(&bs->done);
+ INIT_WORK(&bs->work, bcm2708_work);
+
+ bs->base = ioremap(regs->start, resource_size(regs));
+ if (!bs->base) {
+ dev_err(&pdev->dev, "could not remap memory\n");
+ goto out_master_put;
+ }
+
+ bs->workq = create_singlethread_workqueue(dev_name(&pdev->dev));
+ if (!bs->workq) {
+ dev_err(&pdev->dev, "could not create workqueue\n");
+ goto out_iounmap;
+ }
+
+ bs->irq = irq;
+ bs->clk = clk;
+ bs->stopping = false;
+
+ err = request_irq(irq, bcm2708_spi_interrupt, 0, dev_name(&pdev->dev),
+ master);
+ if (err) {
+ dev_err(&pdev->dev, "could not request IRQ: %d\n", err);
+ goto out_workqueue;
+ }
+
+ /* initialise the hardware */
+ clk_enable(clk);
+ bcm2708_wr(bs, SPI_CS, SPI_CS_REN | SPI_CS_CLEAR_RX | SPI_CS_CLEAR_TX);
+
+ err = spi_register_master(master);
+ if (err) {
+ dev_err(&pdev->dev, "could not register SPI master: %d\n", err);
+ goto out_free_irq;
+ }
+
+ dev_info(&pdev->dev, "SPI Controller at 0x%08lx (irq %d)\n",
+ (unsigned long)regs->start, irq);
+
+ return 0;
+
+out_free_irq:
+ free_irq(bs->irq, master);
+out_workqueue:
+ destroy_workqueue(bs->workq);
+out_iounmap:
+ iounmap(bs->base);
+out_master_put:
+ spi_master_put(master);
+out_clk_put:
+ clk_put(clk);
+ return err;
+}
+
+static int bcm2708_spi_remove(struct platform_device *pdev)
+{
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct bcm2708_spi *bs = spi_master_get_devdata(master);
+
+ /* reset the hardware and block queue progress */
+ spin_lock_irq(&bs->lock);
+ bs->stopping = true;
+ bcm2708_wr(bs, SPI_CS, SPI_CS_CLEAR_RX | SPI_CS_CLEAR_TX);
+ spin_unlock_irq(&bs->lock);
+
+ flush_work_sync(&bs->work);
+
+ clk_disable(bs->clk);
+ clk_put(bs->clk);
+ free_irq(bs->irq, master);
+ iounmap(bs->base);
+
+ spi_unregister_master(master);
+
+ return 0;
+}
+
+static struct platform_driver bcm2708_spi_driver = {
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+ .probe = bcm2708_spi_probe,
+ .remove = bcm2708_spi_remove,
+};
+
+
+static int __init bcm2708_spi_init(void)
+{
+ return platform_driver_probe(&bcm2708_spi_driver, bcm2708_spi_probe);
+}
+module_init(bcm2708_spi_init);
+
+static void __exit bcm2708_spi_exit(void)
+{
+ platform_driver_unregister(&bcm2708_spi_driver);
+}
+module_exit(bcm2708_spi_exit);
+
+
+//module_platform_driver(bcm2708_spi_driver);
+
+MODULE_DESCRIPTION("SPI controller driver for Broadcom BCM2708");
+MODULE_AUTHOR("Chris Boot <bootc@bootc.net>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRV_NAME);
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