This patch adds support for the SPI controller found on the Broadcom BCM63xx SoCs. Signed-off-by: Tanguy Bouzeloc <tanguy.bouzeloc@xxxxxxxxx> Signed-off-by: Florian Fainelli <florian@xxxxxxxxxxx> --- The platform related changes have been submitted on the linux-mips ml: http://www.linux-mips.org/archives/linux-mips/2011-11/msg00547.html Ralf, if Grant is okay with that patch, it probably makes sense to merge this controller via your tree since it depends on the arch/mips/bcm63xx knobs. drivers/spi/Kconfig | 6 + drivers/spi/Makefile | 1 + drivers/spi/spi-bcm63xx.c | 494 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 501 insertions(+), 0 deletions(-) create mode 100644 drivers/spi/spi-bcm63xx.c diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 52e2900..8aecc4e 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -94,6 +94,12 @@ config SPI_AU1550 If you say yes to this option, support will be included for the Au1550 SPI controller (may also work with Au1200,Au1210,Au1250). +config SPI_BCM63XX + tristate "Broadcom BCM63xx SPI controller" + depends on BCM63XX + help + Enable support for the SPI controller on the Broadcom BCM63xx SoCs. + config SPI_BITBANG tristate "Utilities for Bitbanging SPI masters" help diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 61c3261..be38f73 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_SPI_ALTERA) += spi-altera.o obj-$(CONFIG_SPI_ATMEL) += spi-atmel.o obj-$(CONFIG_SPI_ATH79) += spi-ath79.o obj-$(CONFIG_SPI_AU1550) += spi-au1550.o +obj-$(CONFIG_SPI_BCM63XX) += spi-bcm63xx.o obj-$(CONFIG_SPI_BFIN) += spi-bfin5xx.o obj-$(CONFIG_SPI_BFIN_SPORT) += spi-bfin-sport.o obj-$(CONFIG_SPI_BITBANG) += spi-bitbang.o diff --git a/drivers/spi/spi-bcm63xx.c b/drivers/spi/spi-bcm63xx.c new file mode 100644 index 0000000..9f01fc8 --- /dev/null +++ b/drivers/spi/spi-bcm63xx.c @@ -0,0 +1,494 @@ +/* + * Broadcom BCM63xx SPI controller support + * + * Copyright (C) 2009-2011 Florian Fainelli <florian@xxxxxxxxxxx> + * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@xxxxxxxxx> + * + * 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/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_readw(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 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; + u32 hz; + unsigned int div; + + 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 64: + clk_cfg = SPI_CLK_0_781MHZ; + break; + case 128: + default: + /* Set to slowest mode for compatibility */ + clk_cfg = SPI_CLK_0_391MHZ; + break; + } + + bcm_spi_writeb(bs, clk_cfg, 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 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 __init 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 = -ENODEV; + goto out; + } + + master = spi_alloc_master(dev, sizeof(*bs)); + if (!master) { + dev_err(dev, "out of memory\n"); + ret = -ENOMEM; + goto out_free; + } + + bs = spi_master_get_devdata(master); + init_completion(&bs->done); + + platform_set_drvdata(pdev, master); + bs->pdev = pdev; + + if (!request_mem_region(r->start, resource_size(r), PFX)) { + dev_err(dev, "iomem request failed\n"); + ret = -ENXIO; + goto out_put_master; + } + + bs->regs = ioremap_nocache(r->start, resource_size(r)); + if (!bs->regs) { + dev_err(dev, "unable to ioremap regs\n"); + ret = -ENOMEM; + goto out_put_master; + } + 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) { + dev_err(dev, "unable to request irq\n"); + goto out_unmap; + } + + 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_reset_hw; + } + + 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_reset_hw: + clk_disable(clk); + free_irq(irq, master); +out_unmap: + iounmap(bs->regs); +out_put_master: + spi_master_put(master); +out_free: + clk_put(clk); +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); + struct resource *r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + + /* 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); + + free_irq(bs->irq, master); + iounmap(bs->regs); + release_mem_region(r->start, r->end - r->start); + platform_set_drvdata(pdev, 0); + spi_unregister_master(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 spi_master *master = platform_get_drvdata(pdev); + 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 = __exit_p(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@xxxxxxxxxxx>"); +MODULE_AUTHOR("Tanguy Bouzeloc <tanguy.bouzeloc@xxxxxxxxx>"); +MODULE_DESCRIPTION("Broadcom BCM63xx SPI Controller driver"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(DRV_VER); -- 1.7.5.4
