--- /dev/null
+/*
+ * Broadcom BCM63xx SPI controller support
+ *
+ * Copyright (C) 2009-2011 Florian Fainelli <florian@openwrt.org>
+ * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.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.
+ *
+ * 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., 51 Franklin Street, Fifth Floor,
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/spi/spi.h>
+#include <linux/completion.h>
+#include <linux/err.h>
+
+#include <bcm63xx_dev_spi.h>
+
+#define PFX KBUILD_MODNAME
+#define DRV_VER "0.1.2"
+
+struct bcm63xx_spi {
+ spinlock_t lock;
+ int stopping;
+ struct completion done;
+
+ void __iomem *regs;
+ int irq;
+
+ /* Platform data */
+ u32 speed_hz;
+ unsigned fifo_size;
+
+ /* Data buffers */
+ const unsigned char *tx_ptr;
+ unsigned char *rx_ptr;
+
+ /* data iomem */
+ u8 __iomem *tx_io;
+ const u8 __iomem *rx_io;
+
+ int remaining_bytes;
+
+ struct clk *clk;
+ struct platform_device *pdev;
+};
+
+static inline u8 bcm_spi_readb(struct bcm63xx_spi *bs,
+ unsigned int offset)
+{
+ return bcm_readb(bs->regs + bcm63xx_spireg(offset));
+}
+
+static inline u16 bcm_spi_readw(struct bcm63xx_spi *bs,
+ unsigned int offset)
+{
+ return bcm_readw(bs->regs + bcm63xx_spireg(offset));
+}
+
+static inline void bcm_spi_writeb(struct bcm63xx_spi *bs,
+ u8 value, unsigned int offset)
+{
+ bcm_writeb(value, bs->regs + bcm63xx_spireg(offset));
+}
+
+static inline void bcm_spi_writew(struct bcm63xx_spi *bs,
+ u16 value, unsigned int offset)
+{
+ bcm_writew(value, bs->regs + bcm63xx_spireg(offset));
+}
+
+static const unsigned bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = {
+ { 20000000, SPI_CLK_20MHZ },
+ { 12500000, SPI_CLK_12_50MHZ },
+ { 6250000, SPI_CLK_6_250MHZ },
+ { 3125000, SPI_CLK_3_125MHZ },
+ { 1563000, SPI_CLK_1_563MHZ },
+ { 781000, SPI_CLK_0_781MHZ },
+ { 391000, SPI_CLK_0_391MHZ }
+};
+
+static int bcm63xx_spi_setup_transfer(struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
+ u8 bits_per_word;
+ u8 clk_cfg, reg;
+ u32 hz;
+ int i;
+
+ bits_per_word = (t) ? t->bits_per_word : spi->bits_per_word;
+ hz = (t) ? t->speed_hz : spi->max_speed_hz;
+ if (bits_per_word != 8) {
+ dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
+ __func__, bits_per_word);
+ return -EINVAL;
+ }
+
+ if (spi->chip_select > spi->master->num_chipselect) {
+ dev_err(&spi->dev, "%s, unsupported slave %d\n",
+ __func__, spi->chip_select);
+ return -EINVAL;
+ }
+
+ /* Find the closest clock configuration */
+ for (i = 0; i < SPI_CLK_MASK; i++) {
+ if (hz <= bcm63xx_spi_freq_table[i][0]) {
+ clk_cfg = bcm63xx_spi_freq_table[i][1];
+ break;
+ }
+ }
+
+ /* No matching configuration found, default to lowest */
+ if (i == SPI_CLK_MASK)
+ clk_cfg = SPI_CLK_0_391MHZ;
+
+ /* clear existing clock configuration bits of the register */
+ reg = bcm_spi_readb(bs, SPI_CLK_CFG);
+ reg &= ~SPI_CLK_MASK;
+ reg |= clk_cfg;
+
+ bcm_spi_writeb(bs, reg, SPI_CLK_CFG);
+ dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n",
+ clk_cfg, hz);
+
+ return 0;
+}
+
+/* the spi->mode bits understood by this driver: */
+#define MODEBITS (SPI_CPOL | SPI_CPHA)
+
+static int bcm63xx_spi_setup(struct spi_device *spi)
+{
+ struct bcm63xx_spi *bs;
+ int ret;
+
+ bs = spi_master_get_devdata(spi->master);
+
+ if (bs->stopping)
+ return -ESHUTDOWN;
+
+ if (!spi->bits_per_word)
+ spi->bits_per_word = 8;
+
+ if (spi->mode & ~MODEBITS) {
+ dev_err(&spi->dev, "%s, unsupported mode bits %x\n",
+ __func__, spi->mode & ~MODEBITS);
+ return -EINVAL;
+ }
+
+ ret = bcm63xx_spi_setup_transfer(spi, NULL);
+ if (ret < 0) {
+ dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
+ spi->mode & ~MODEBITS);
+ return ret;
+ }
+
+ dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec/bit\n",
+ __func__, spi->mode & MODEBITS, spi->bits_per_word, 0);
+
+ return 0;
+}
+
+/* Fill the TX FIFO with as many bytes as possible */
+static void bcm63xx_spi_fill_tx_fifo(struct bcm63xx_spi *bs)
+{
+ u8 size;
+
+ /* Fill the Tx FIFO with as many bytes as possible */
+ size = bs->remaining_bytes < bs->fifo_size ? bs->remaining_bytes :
+ bs->fifo_size;
+ memcpy_toio(bs->tx_io, bs->tx_ptr, size);
+ bs->remaining_bytes -= size;
+}
+
+static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
+{
+ struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
+ u16 msg_ctl;
+ u16 cmd;
+
+ dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
+ t->tx_buf, t->rx_buf, t->len);
+
+ /* Transmitter is inhibited */
+ bs->tx_ptr = t->tx_buf;
+ bs->rx_ptr = t->rx_buf;
+ init_completion(&bs->done);
+
+ if (t->tx_buf) {
+ bs->remaining_bytes = t->len;
+ bcm63xx_spi_fill_tx_fifo(bs);
+ }
+
+ /* Enable the command done interrupt which
+ * we use to determine completion of a command */
+ bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
+
+ /* Fill in the Message control register */
+ msg_ctl = (t->len << SPI_BYTE_CNT_SHIFT);
+
+ if (t->rx_buf && t->tx_buf)
+ msg_ctl |= (SPI_FD_RW << SPI_MSG_TYPE_SHIFT);
+ else if (t->rx_buf)
+ msg_ctl |= (SPI_HD_R << SPI_MSG_TYPE_SHIFT);
+ else if (t->tx_buf)
+ msg_ctl |= (SPI_HD_W << SPI_MSG_TYPE_SHIFT);
+
+ bcm_spi_writew(bs, msg_ctl, SPI_MSG_CTL);
+
+ /* Issue the transfer */
+ cmd = SPI_CMD_START_IMMEDIATE;
+ cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
+ cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT);
+ bcm_spi_writew(bs, cmd, SPI_CMD);
+ wait_for_completion(&bs->done);
+
+ /* Disable the CMD_DONE interrupt */
+ bcm_spi_writeb(bs, 0, SPI_INT_MASK);
+
+ return t->len - bs->remaining_bytes;
+}
+
+static int bcm63xx_transfer(struct spi_device *spi, struct spi_message *m)
+{
+ struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
+ struct spi_transfer *t;
+ int ret = 0;
+
+ if (unlikely(list_empty(&m->transfers)))
+ return -EINVAL;
+
+ if (bs->stopping)
+ return -ESHUTDOWN;
+
+ list_for_each_entry(t, &m->transfers, transfer_list) {
+ ret += bcm63xx_txrx_bufs(spi, t);
+ }
+
+ m->complete(m->context);
+
+ return ret;
+}
+
+/* This driver supports single master mode only. Hence
+ * CMD_DONE is the only interrupt we care about
+ */
+static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id)
+{
+ struct spi_master *master = (struct spi_master *)dev_id;
+ struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+ u8 intr;
+ u16 cmd;
+
+ /* Read interupts and clear them immediately */
+ intr = bcm_spi_readb(bs, SPI_INT_STATUS);
+ bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
+ bcm_spi_writeb(bs, 0, SPI_INT_MASK);
+
+ /* A tansfer completed */
+ if (intr & SPI_INTR_CMD_DONE) {
+ u8 rx_tail;
+
+ rx_tail = bcm_spi_readb(bs, SPI_RX_TAIL);
+
+ /* Read out all the data */
+ if (rx_tail)
+ memcpy_fromio(bs->rx_ptr, bs->rx_io, rx_tail);
+
+ /* See if there is more data to send */
+ if (bs->remaining_bytes > 0) {
+ bcm63xx_spi_fill_tx_fifo(bs);
+
+ /* Start the transfer */
+ bcm_spi_writew(bs, SPI_HD_W << SPI_MSG_TYPE_SHIFT,
+ SPI_MSG_CTL);
+ cmd = bcm_spi_readw(bs, SPI_CMD);
+ cmd |= SPI_CMD_START_IMMEDIATE;
+ cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
+ bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
+ bcm_spi_writew(bs, cmd, SPI_CMD);
+ } else {
+ complete(&bs->done);
+ }
+ }
+
+ return IRQ_HANDLED;
+}
+
+
+static int __devinit bcm63xx_spi_probe(struct platform_device *pdev)
+{
+ struct resource *r;
+ struct device *dev = &pdev->dev;
+ struct bcm63xx_spi_pdata *pdata = pdev->dev.platform_data;
+ int irq;
+ struct spi_master *master;
+ struct clk *clk;
+ struct bcm63xx_spi *bs;
+ int ret;
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!r) {
+ dev_err(dev, "no iomem\n");
+ ret = -ENXIO;
+ goto out;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(dev, "no irq\n");
+ ret = -ENXIO;
+ goto out;
+ }
+
+ clk = clk_get(dev, "spi");
+ if (IS_ERR(clk)) {
+ dev_err(dev, "no clock for device\n");
+ ret = PTR_ERR(clk);
+ goto out;
+ }
+
+ master = spi_alloc_master(dev, sizeof(*bs));
+ if (!master) {
+ dev_err(dev, "out of memory\n");
+ ret = -ENOMEM;
+ goto out_clk;
+ }
+
+ bs = spi_master_get_devdata(master);
+ init_completion(&bs->done);
+
+ platform_set_drvdata(pdev, master);
+ bs->pdev = pdev;
+
+ if (!devm_request_mem_region(&pdev->dev, r->start,
+ resource_size(r), PFX)) {
+ dev_err(dev, "iomem request failed\n");
+ ret = -ENXIO;
+ goto out_err;
+ }
+
+ bs->regs = devm_ioremap_nocache(&pdev->dev, r->start,
+ resource_size(r));
+ if (!bs->regs) {
+ dev_err(dev, "unable to ioremap regs\n");
+ ret = -ENOMEM;
+ goto out_err;
+ }
+
+ bs->irq = irq;
+ bs->clk = clk;
+ bs->fifo_size = pdata->fifo_size;
+
+ ret = devm_request_irq(&pdev->dev, irq, bcm63xx_spi_interrupt, 0,
+ pdev->name, master);
+ if (ret) {
+ dev_err(dev, "unable to request irq\n");
+ goto out_err;
+ }
+
+ master->bus_num = pdata->bus_num;
+ master->num_chipselect = pdata->num_chipselect;
+ master->setup = bcm63xx_spi_setup;
+ master->transfer = bcm63xx_transfer;
+ bs->speed_hz = pdata->speed_hz;
+ bs->stopping = 0;
+ bs->tx_io = (u8 *)(bs->regs + bcm63xx_spireg(SPI_MSG_DATA));
+ bs->rx_io = (const u8 *)(bs->regs + bcm63xx_spireg(SPI_RX_DATA));
+ spin_lock_init(&bs->lock);
+
+ /* Initialize hardware */
+ clk_enable(bs->clk);
+ bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
+
+ /* register and we are done */
+ ret = spi_register_master(master);
+ if (ret) {
+ dev_err(dev, "spi register failed\n");
+ goto out_clk_disable;
+ }
+
+ dev_info(dev, "at 0x%08x (irq %d, FIFOs size %d) v%s\n",
+ r->start, irq, bs->fifo_size, DRV_VER);
+
+ return 0;
+
+out_clk_disable:
+ clk_disable(clk);
+out_err:
+ platform_set_drvdata(pdev, NULL);
+ spi_master_put(master);
+out_clk:
+ clk_put(clk);
+out:
+ return ret;
+}
+
+static int __devexit bcm63xx_spi_remove(struct platform_device *pdev)
+{
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+
+ /* reset spi block */
+ bcm_spi_writeb(bs, 0, SPI_INT_MASK);
+ spin_lock(&bs->lock);
+ bs->stopping = 1;
+
+ /* HW shutdown */
+ clk_disable(bs->clk);
+ clk_put(bs->clk);
+
+ spin_unlock(&bs->lock);
+ platform_set_drvdata(pdev, 0);
+ spi_unregister_master(master);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int bcm63xx_spi_suspend(struct device *dev)
+{
+ struct spi_master *master =
+ platform_get_drvdata(to_platform_device(dev));
+ struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+
+ clk_disable(bs->clk);
+
+ return 0;
+}
+
+static int bcm63xx_spi_resume(struct device *dev)
+{
+ struct spi_master *master =
+ platform_get_drvdata(to_platform_device(dev));
+ struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+
+ clk_enable(bs->clk);
+
+ return 0;
+}
+
+static const struct dev_pm_ops bcm63xx_spi_pm_ops = {
+ .suspend = bcm63xx_spi_suspend,
+ .resume = bcm63xx_spi_resume,
+};
+
+#define BCM63XX_SPI_PM_OPS (&bcm63xx_spi_pm_ops)
+#else
+#define BCM63XX_SPI_PM_OPS NULL
+#endif
+
+static struct platform_driver bcm63xx_spi_driver = {
+ .driver = {
+ .name = "bcm63xx-spi",
+ .owner = THIS_MODULE,
+ .pm = BCM63XX_SPI_PM_OPS,
+ },
+ .probe = bcm63xx_spi_probe,
+ .remove = __devexit_p(bcm63xx_spi_remove),
+};
+
+module_platform_driver(bcm63xx_spi_driver);
+
+MODULE_ALIAS("platform:bcm63xx_spi");
+MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
+MODULE_AUTHOR("Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>");
+MODULE_DESCRIPTION("Broadcom BCM63xx SPI Controller driver");
+MODULE_LICENSE("GPL");
git.openpandora.org / pandora-kernel.git / commitdiff