+++ /dev/null
-/*
- * Broadcom BCM63xx SPI controller support
- *
- * Copyright (C) 2009 Florian Fainelli <florian@openwrt.org>
- *
- * 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/module.h>
-#include <linux/platform_device.h>
-#include <linux/delay.h>
-#include <linux/interrupt.h>
-#include <linux/spi/spi.h>
-#include <linux/spi/spi_bitbang.h>
-#include <linux/gpio.h>
-#include <linux/completion.h>
-#include <linux/err.h>
-
-#include <bcm63xx_io.h>
-#include <bcm63xx_regs.h>
-#include <bcm63xx_dev_spi.h>
-
-#define PFX KBUILD_MODNAME
-#define DRV_VER "0.1.2"
-
-struct bcm63xx_spi {
- /* bitbang has to be first */
- struct spi_bitbang bitbang;
- 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;
- int remaining_bytes;
-
- struct clk *clk;
- struct resource *ioarea;
- struct platform_device *pdev;
-};
-
-static void bcm63xx_spi_chipselect(struct spi_device *spi, int is_on)
-{
- struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
- u16 val;
-
- val = bcm_spi_readw(bs->regs, SPI_CMD);
- if (is_on == BITBANG_CS_INACTIVE)
- val |= SPI_CMD_NOOP;
- else if (is_on == BITBANG_CS_ACTIVE)
- val |= (1 << spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT);
-
- bcm_spi_writew(val, bs->regs, SPI_CMD);
-}
-
-static int bcm63xx_spi_setup_transfer(struct spi_device *spi,
- struct spi_transfer *t)
-{
- u8 bits_per_word;
- u8 clk_cfg;
- u32 hz;
- unsigned int div;
-
- struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
-
- 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;
- }
-
- /* Check clock setting */
- div = (bs->speed_hz / hz);
- switch (div) {
- case 2:
- clk_cfg = SPI_CLK_25MHZ;
- break;
- case 4:
- clk_cfg = SPI_CLK_12_50MHZ;
- break;
- case 8:
- clk_cfg = SPI_CLK_6_250MHZ;
- break;
- case 16:
- clk_cfg = SPI_CLK_3_125MHZ;
- break;
- case 32:
- clk_cfg = SPI_CLK_1_563MHZ;
- break;
- case 128:
- clk_cfg = SPI_CLK_0_781MHZ;
- break;
- case 64:
- default:
- /* Set to slowest mode for compatibility */
- clk_cfg = SPI_CLK_0_781MHZ;
- break;
- }
-
- bcm_spi_writeb(clk_cfg, bs->regs, SPI_CLK_CFG);
- dev_dbg(&spi->dev, "Setting clock register to %d (hz %d, cmd %02x)\n",
- div, hz, clk_cfg);
-
- 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 spi_bitbang *bitbang;
- struct bcm63xx_spi *bs;
- int retval;
-
- bs = spi_master_get_devdata(spi->master);
- bitbang = &bs->bitbang;
-
- 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;
- }
-
- retval = bcm63xx_spi_setup_transfer(spi, NULL);
- if (retval < 0) {
- dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
- spi->mode & ~MODEBITS);
- return retval;
- }
-
- 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 tail;
-
- /* Fill the Tx FIFO with as many bytes as possible */
- tail = bcm_spi_readb(bs->regs, SPI_MSG_TAIL);
- while ((tail < bs->fifo_size) && (bs->remaining_bytes > 0)) {
- if (bs->tx_ptr)
- bcm_spi_writeb(*bs->tx_ptr++, bs->regs, SPI_MSG_DATA);
- else
- bcm_spi_writeb(0, bs->regs, SPI_MSG_DATA);
- bs->remaining_bytes--;
- tail = bcm_spi_readb(bs->regs, SPI_MSG_TAIL);
- }
-}
-
-static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
-{
- struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
- u8 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;
- bs->remaining_bytes = t->len;
- init_completion(&bs->done);
-
- bcm63xx_spi_fill_tx_fifo(bs);
-
- /* Enable the command done interrupt which
- * we use to determine completion of a command */
- bcm_spi_writeb(SPI_INTR_CMD_DONE, bs->regs, SPI_INT_MASK);
-
- /* Fill in the Message control register */
- msg_ctl = bcm_spi_readb(bs->regs, SPI_MSG_CTL);
- msg_ctl |= (t->len << SPI_BYTE_CNT_SHIFT);
- msg_ctl |= (SPI_FD_RW << SPI_MSG_TYPE_SHIFT);
- bcm_spi_writeb(msg_ctl, bs->regs, SPI_MSG_CTL);
-
- /* Issue the transfer */
- cmd = bcm_spi_readb(bs->regs, SPI_CMD);
- cmd |= SPI_CMD_START_IMMEDIATE;
- cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
- bcm_spi_writeb(cmd, bs->regs, SPI_CMD);
-
- wait_for_completion(&bs->done);
-
- /* Disable the CMD_DONE interrupt */
- bcm_spi_writeb(~(SPI_INTR_CMD_DONE), bs->regs, SPI_INT_MASK);
-
- return t->len - bs->remaining_bytes;
-}
-
-/* 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->regs, SPI_INT_STATUS);
- bcm_spi_writeb(SPI_INTR_CLEAR_ALL, bs->regs, SPI_INT_MASK);
-
- /* A tansfer completed */
- if (intr & SPI_INTR_CMD_DONE) {
- u8 rx_empty;
-
- rx_empty = bcm_spi_readb(bs->regs, SPI_ST);
- /* Read out all the data */
- while ((rx_empty & SPI_RX_EMPTY) == 0) {
- u8 data;
-
- data = bcm_spi_readb(bs->regs, SPI_RX_DATA);
- if (bs->rx_ptr)
- *bs->rx_ptr++ = data;
-
- rx_empty = bcm_spi_readb(bs->regs, SPI_RX_EMPTY);
- }
-
- /* See if there is more data to send */
- if (bs->remaining_bytes > 0) {
- bcm63xx_spi_fill_tx_fifo(bs);
-
- /* Start the transfer */
- cmd = bcm_spi_readb(bs->regs, SPI_CMD);
- cmd |= SPI_CMD_START_IMMEDIATE;
- cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
- bcm_spi_writeb(cmd, bs->regs, SPI_CMD);
- } else
- complete(&bs->done);
- }
-
- return IRQ_HANDLED;
-}
-
-
-static int __init bcm63xx_spi_probe(struct platform_device *pdev)
-{
- struct resource *r;
- 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) {
- ret = -ENXIO;
- goto out;
- }
-
- irq = platform_get_irq(pdev, 0);
- if (irq < 0) {
- ret = -ENXIO;
- goto out;
- }
-
- clk = clk_get(&pdev->dev, "spi");
- if (IS_ERR(clk)) {
- dev_err(&pdev->dev, "No clock for device\n");
- ret = -ENODEV;
- goto out;
- }
-
- master = spi_alloc_master(&pdev->dev, sizeof(struct bcm63xx_spi));
- if (!master) {
- ret = -ENOMEM;
- goto out_free;
- }
-
- bs = spi_master_get_devdata(master);
- bs->bitbang.master = spi_master_get(master);
- bs->bitbang.chipselect = bcm63xx_spi_chipselect;
- bs->bitbang.setup_transfer = bcm63xx_spi_setup_transfer;
- bs->bitbang.txrx_bufs = bcm63xx_txrx_bufs;
- bs->bitbang.master->setup = bcm63xx_spi_setup;
- init_completion(&bs->done);
-
- platform_set_drvdata(pdev, master);
- bs->pdev = pdev;
-
- if (!request_mem_region(r->start,
- r->end - r->start, PFX)) {
- ret = -ENXIO;
- goto out_free;
- }
-
- bs->regs = ioremap_nocache(r->start, r->end - r->start);
- if (!bs->regs) {
- printk(KERN_ERR PFX " unable to ioremap regs\n");
- ret = -ENOMEM;
- goto out_free;
- }
- bs->irq = irq;
- bs->clk = clk;
- bs->fifo_size = pdata->fifo_size;
-
- ret = request_irq(irq, bcm63xx_spi_interrupt, 0,
- pdev->name, master);
- if (ret) {
- printk(KERN_ERR PFX " unable to request irq\n");
- goto out_unmap;
- }
-
- master->bus_num = pdata->bus_num;
- master->num_chipselect = pdata->num_chipselect;
- bs->speed_hz = pdata->speed_hz;
-
- /* Initialize hardware */
- clk_enable(bs->clk);
- bcm_spi_writeb(SPI_INTR_CLEAR_ALL, bs->regs, SPI_INT_MASK);
-
- dev_info(&pdev->dev, " at 0x%08x (irq %d, FIFOs size %d) v%s\n",
- r->start, irq, bs->fifo_size, DRV_VER);
-
- ret = spi_bitbang_start(&bs->bitbang);
- if (ret) {
- dev_err(&pdev->dev, "spi_bitbang_start FAILED\n");
- goto out_reset_hw;
- }
-
- return ret;
-
-out_reset_hw:
- clk_disable(clk);
- free_irq(irq, master);
-out_unmap:
- iounmap(bs->regs);
-out_free:
- clk_put(clk);
- spi_master_put(master);
-out:
- return ret;
-}
-
-static int __exit bcm63xx_spi_remove(struct platform_device *pdev)
-{
- struct spi_master *master = platform_get_drvdata(pdev);
- struct bcm63xx_spi *bs = spi_master_get_devdata(master);
-
- spi_bitbang_stop(&bs->bitbang);
- clk_disable(bs->clk);
- clk_put(bs->clk);
- free_irq(bs->irq, master);
- iounmap(bs->regs);
- platform_set_drvdata(pdev, 0);
- spi_master_put(bs->bitbang.master);
-
- return 0;
-}
-
-#ifdef CONFIG_PM
-static int bcm63xx_spi_suspend(struct platform_device *pdev, pm_message_t mesg)
-{
- struct spi_master *master = platform_get_drvdata(pdev);
- struct bcm63xx_spi *bs = spi_master_get_devdata(master);
-
- clk_disable(bs->clk);
-
- return 0;
-}
-
-static int bcm63xx_spi_resume(struct platform_device *pdev)
-{
- struct bcm63xx_spi *bs = spi_master_get_devdata(master);
- struct bcm63xx_spi *bs = spi_master_get_devdata(master);
-
- clk_enable(bs->clk);
-
- return 0;
-}
-#else
-#define bcm63xx_spi_suspend NULL
-#define bcm63xx_spi_resume NULL
-#endif
-
-static struct platform_driver bcm63xx_spi_driver = {
- .driver = {
- .name = "bcm63xx-spi",
- .owner = THIS_MODULE,
- },
- .probe = bcm63xx_spi_probe,
- .remove = bcm63xx_spi_remove,
- .suspend = bcm63xx_spi_suspend,
- .resume = bcm63xx_spi_resume,
-};
-
-
-static int __init bcm63xx_spi_init(void)
-{
- return platform_driver_register(&bcm63xx_spi_driver);
-}
-
-static void __exit bcm63xx_spi_exit(void)
-{
- platform_driver_unregister(&bcm63xx_spi_driver);
-}
-
-module_init(bcm63xx_spi_init);
-module_exit(bcm63xx_spi_exit);
-
-MODULE_ALIAS("platform:bcm63xx_spi");
-MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
-MODULE_DESCRIPTION("Broadcom BCM63xx SPI Controller driver");
-MODULE_LICENSE("GPL");
-MODULE_VERSION(DRV_VER);
projects / openwrt-10.03 / .git / blobdiff