spi: add Broadcom BCM63xx SPI controller driver
This patch adds support for the SPI controller found on the Broadcom BCM63xx SoCs. Signed-off-by: Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com> Signed-off-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This commit is contained in:
Florian Fainelli
Grant Likely
parent
1cc2df9d6f
commit
b42dfed83d
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@ -94,6 +94,12 @@ config SPI_AU1550
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If you say yes to this option, support will be included for the
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PSC SPI controller found on Au1550, Au1200 and Au1300 series.
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config SPI_BCM63XX
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tristate "Broadcom BCM63xx SPI controller"
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depends on BCM63XX
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help
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Enable support for the SPI controller on the Broadcom BCM63xx SoCs.
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config SPI_BITBANG
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tristate "Utilities for Bitbanging SPI masters"
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help
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@ -14,6 +14,7 @@ obj-$(CONFIG_SPI_ALTERA) += spi-altera.o
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obj-$(CONFIG_SPI_ATMEL) += spi-atmel.o
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obj-$(CONFIG_SPI_ATH79) += spi-ath79.o
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obj-$(CONFIG_SPI_AU1550) += spi-au1550.o
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obj-$(CONFIG_SPI_BCM63XX) += spi-bcm63xx.o
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obj-$(CONFIG_SPI_BFIN) += spi-bfin5xx.o
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obj-$(CONFIG_SPI_BFIN_SPORT) += spi-bfin-sport.o
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obj-$(CONFIG_SPI_BITBANG) += spi-bitbang.o
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@ -0,0 +1,486 @@
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/*
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* Broadcom BCM63xx SPI controller support
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*
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* Copyright (C) 2009-2011 Florian Fainelli <florian@openwrt.org>
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* Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the
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* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/clk.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/delay.h>
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#include <linux/interrupt.h>
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#include <linux/spi/spi.h>
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#include <linux/completion.h>
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#include <linux/err.h>
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#include <bcm63xx_dev_spi.h>
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#define PFX KBUILD_MODNAME
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#define DRV_VER "0.1.2"
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struct bcm63xx_spi {
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spinlock_t lock;
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int stopping;
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struct completion done;
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void __iomem *regs;
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int irq;
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/* Platform data */
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u32 speed_hz;
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unsigned fifo_size;
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/* Data buffers */
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const unsigned char *tx_ptr;
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unsigned char *rx_ptr;
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/* data iomem */
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u8 __iomem *tx_io;
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const u8 __iomem *rx_io;
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int remaining_bytes;
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struct clk *clk;
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struct platform_device *pdev;
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};
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static inline u8 bcm_spi_readb(struct bcm63xx_spi *bs,
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unsigned int offset)
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{
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return bcm_readb(bs->regs + bcm63xx_spireg(offset));
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}
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static inline u16 bcm_spi_readw(struct bcm63xx_spi *bs,
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unsigned int offset)
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{
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return bcm_readw(bs->regs + bcm63xx_spireg(offset));
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}
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static inline void bcm_spi_writeb(struct bcm63xx_spi *bs,
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u8 value, unsigned int offset)
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{
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bcm_writeb(value, bs->regs + bcm63xx_spireg(offset));
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}
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static inline void bcm_spi_writew(struct bcm63xx_spi *bs,
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u16 value, unsigned int offset)
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{
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bcm_writew(value, bs->regs + bcm63xx_spireg(offset));
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}
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static const unsigned bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = {
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{ 20000000, SPI_CLK_20MHZ },
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{ 12500000, SPI_CLK_12_50MHZ },
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{ 6250000, SPI_CLK_6_250MHZ },
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{ 3125000, SPI_CLK_3_125MHZ },
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{ 1563000, SPI_CLK_1_563MHZ },
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{ 781000, SPI_CLK_0_781MHZ },
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{ 391000, SPI_CLK_0_391MHZ }
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};
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static int bcm63xx_spi_setup_transfer(struct spi_device *spi,
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struct spi_transfer *t)
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{
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struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
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u8 bits_per_word;
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u8 clk_cfg, reg;
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u32 hz;
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int i;
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bits_per_word = (t) ? t->bits_per_word : spi->bits_per_word;
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hz = (t) ? t->speed_hz : spi->max_speed_hz;
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if (bits_per_word != 8) {
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dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
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__func__, bits_per_word);
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return -EINVAL;
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}
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if (spi->chip_select > spi->master->num_chipselect) {
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dev_err(&spi->dev, "%s, unsupported slave %d\n",
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__func__, spi->chip_select);
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return -EINVAL;
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}
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/* Find the closest clock configuration */
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for (i = 0; i < SPI_CLK_MASK; i++) {
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if (hz <= bcm63xx_spi_freq_table[i][0]) {
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clk_cfg = bcm63xx_spi_freq_table[i][1];
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break;
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}
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}
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/* No matching configuration found, default to lowest */
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if (i == SPI_CLK_MASK)
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clk_cfg = SPI_CLK_0_391MHZ;
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/* clear existing clock configuration bits of the register */
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reg = bcm_spi_readb(bs, SPI_CLK_CFG);
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reg &= ~SPI_CLK_MASK;
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reg |= clk_cfg;
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bcm_spi_writeb(bs, reg, SPI_CLK_CFG);
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dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n",
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clk_cfg, hz);
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return 0;
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}
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/* the spi->mode bits understood by this driver: */
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#define MODEBITS (SPI_CPOL | SPI_CPHA)
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static int bcm63xx_spi_setup(struct spi_device *spi)
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{
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struct bcm63xx_spi *bs;
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int ret;
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bs = spi_master_get_devdata(spi->master);
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if (bs->stopping)
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return -ESHUTDOWN;
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if (!spi->bits_per_word)
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spi->bits_per_word = 8;
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if (spi->mode & ~MODEBITS) {
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dev_err(&spi->dev, "%s, unsupported mode bits %x\n",
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__func__, spi->mode & ~MODEBITS);
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return -EINVAL;
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}
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ret = bcm63xx_spi_setup_transfer(spi, NULL);
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if (ret < 0) {
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dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
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spi->mode & ~MODEBITS);
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return ret;
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}
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dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec/bit\n",
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__func__, spi->mode & MODEBITS, spi->bits_per_word, 0);
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return 0;
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}
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/* Fill the TX FIFO with as many bytes as possible */
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static void bcm63xx_spi_fill_tx_fifo(struct bcm63xx_spi *bs)
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{
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u8 size;
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/* Fill the Tx FIFO with as many bytes as possible */
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size = bs->remaining_bytes < bs->fifo_size ? bs->remaining_bytes :
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bs->fifo_size;
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memcpy_toio(bs->tx_io, bs->tx_ptr, size);
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bs->remaining_bytes -= size;
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}
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static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
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{
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struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
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u16 msg_ctl;
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u16 cmd;
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dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
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t->tx_buf, t->rx_buf, t->len);
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/* Transmitter is inhibited */
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bs->tx_ptr = t->tx_buf;
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bs->rx_ptr = t->rx_buf;
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init_completion(&bs->done);
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if (t->tx_buf) {
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bs->remaining_bytes = t->len;
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bcm63xx_spi_fill_tx_fifo(bs);
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}
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/* Enable the command done interrupt which
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* we use to determine completion of a command */
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bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
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/* Fill in the Message control register */
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msg_ctl = (t->len << SPI_BYTE_CNT_SHIFT);
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if (t->rx_buf && t->tx_buf)
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msg_ctl |= (SPI_FD_RW << SPI_MSG_TYPE_SHIFT);
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else if (t->rx_buf)
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msg_ctl |= (SPI_HD_R << SPI_MSG_TYPE_SHIFT);
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else if (t->tx_buf)
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msg_ctl |= (SPI_HD_W << SPI_MSG_TYPE_SHIFT);
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bcm_spi_writew(bs, msg_ctl, SPI_MSG_CTL);
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/* Issue the transfer */
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cmd = SPI_CMD_START_IMMEDIATE;
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cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
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cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT);
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bcm_spi_writew(bs, cmd, SPI_CMD);
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wait_for_completion(&bs->done);
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/* Disable the CMD_DONE interrupt */
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bcm_spi_writeb(bs, 0, SPI_INT_MASK);
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return t->len - bs->remaining_bytes;
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}
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static int bcm63xx_transfer(struct spi_device *spi, struct spi_message *m)
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{
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struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
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struct spi_transfer *t;
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int ret = 0;
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if (unlikely(list_empty(&m->transfers)))
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return -EINVAL;
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if (bs->stopping)
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return -ESHUTDOWN;
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list_for_each_entry(t, &m->transfers, transfer_list) {
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ret += bcm63xx_txrx_bufs(spi, t);
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}
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m->complete(m->context);
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return ret;
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}
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/* This driver supports single master mode only. Hence
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* CMD_DONE is the only interrupt we care about
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*/
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static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id)
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{
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struct spi_master *master = (struct spi_master *)dev_id;
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struct bcm63xx_spi *bs = spi_master_get_devdata(master);
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u8 intr;
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u16 cmd;
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/* Read interupts and clear them immediately */
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intr = bcm_spi_readb(bs, SPI_INT_STATUS);
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bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
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bcm_spi_writeb(bs, 0, SPI_INT_MASK);
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/* A tansfer completed */
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if (intr & SPI_INTR_CMD_DONE) {
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u8 rx_tail;
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rx_tail = bcm_spi_readb(bs, SPI_RX_TAIL);
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/* Read out all the data */
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if (rx_tail)
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memcpy_fromio(bs->rx_ptr, bs->rx_io, rx_tail);
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/* See if there is more data to send */
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if (bs->remaining_bytes > 0) {
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bcm63xx_spi_fill_tx_fifo(bs);
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/* Start the transfer */
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bcm_spi_writew(bs, SPI_HD_W << SPI_MSG_TYPE_SHIFT,
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SPI_MSG_CTL);
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cmd = bcm_spi_readw(bs, SPI_CMD);
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cmd |= SPI_CMD_START_IMMEDIATE;
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cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
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bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
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bcm_spi_writew(bs, cmd, SPI_CMD);
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} else {
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complete(&bs->done);
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}
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}
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return IRQ_HANDLED;
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}
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static int __devinit bcm63xx_spi_probe(struct platform_device *pdev)
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{
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struct resource *r;
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struct device *dev = &pdev->dev;
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struct bcm63xx_spi_pdata *pdata = pdev->dev.platform_data;
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int irq;
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struct spi_master *master;
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struct clk *clk;
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struct bcm63xx_spi *bs;
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int ret;
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r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!r) {
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dev_err(dev, "no iomem\n");
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ret = -ENXIO;
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goto out;
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}
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irq = platform_get_irq(pdev, 0);
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if (irq < 0) {
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dev_err(dev, "no irq\n");
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ret = -ENXIO;
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goto out;
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}
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clk = clk_get(dev, "spi");
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if (IS_ERR(clk)) {
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dev_err(dev, "no clock for device\n");
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ret = PTR_ERR(clk);
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goto out;
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}
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master = spi_alloc_master(dev, sizeof(*bs));
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if (!master) {
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dev_err(dev, "out of memory\n");
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ret = -ENOMEM;
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goto out_clk;
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}
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bs = spi_master_get_devdata(master);
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init_completion(&bs->done);
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platform_set_drvdata(pdev, master);
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bs->pdev = pdev;
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if (!devm_request_mem_region(&pdev->dev, r->start,
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resource_size(r), PFX)) {
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dev_err(dev, "iomem request failed\n");
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ret = -ENXIO;
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goto out_err;
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}
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bs->regs = devm_ioremap_nocache(&pdev->dev, r->start,
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resource_size(r));
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if (!bs->regs) {
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dev_err(dev, "unable to ioremap regs\n");
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ret = -ENOMEM;
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goto out_err;
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}
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bs->irq = irq;
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bs->clk = clk;
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bs->fifo_size = pdata->fifo_size;
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ret = devm_request_irq(&pdev->dev, irq, bcm63xx_spi_interrupt, 0,
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pdev->name, master);
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if (ret) {
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dev_err(dev, "unable to request irq\n");
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goto out_err;
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}
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master->bus_num = pdata->bus_num;
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master->num_chipselect = pdata->num_chipselect;
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master->setup = bcm63xx_spi_setup;
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master->transfer = bcm63xx_transfer;
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bs->speed_hz = pdata->speed_hz;
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bs->stopping = 0;
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bs->tx_io = (u8 *)(bs->regs + bcm63xx_spireg(SPI_MSG_DATA));
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bs->rx_io = (const u8 *)(bs->regs + bcm63xx_spireg(SPI_RX_DATA));
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spin_lock_init(&bs->lock);
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/* Initialize hardware */
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clk_enable(bs->clk);
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bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
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/* register and we are done */
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ret = spi_register_master(master);
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if (ret) {
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dev_err(dev, "spi register failed\n");
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goto out_clk_disable;
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}
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dev_info(dev, "at 0x%08x (irq %d, FIFOs size %d) v%s\n",
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r->start, irq, bs->fifo_size, DRV_VER);
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return 0;
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out_clk_disable:
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clk_disable(clk);
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out_err:
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platform_set_drvdata(pdev, NULL);
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spi_master_put(master);
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out_clk:
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clk_put(clk);
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out:
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return ret;
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}
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static int __devexit bcm63xx_spi_remove(struct platform_device *pdev)
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{
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struct spi_master *master = platform_get_drvdata(pdev);
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struct bcm63xx_spi *bs = spi_master_get_devdata(master);
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/* reset spi block */
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bcm_spi_writeb(bs, 0, SPI_INT_MASK);
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spin_lock(&bs->lock);
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bs->stopping = 1;
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/* HW shutdown */
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clk_disable(bs->clk);
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clk_put(bs->clk);
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spin_unlock(&bs->lock);
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platform_set_drvdata(pdev, 0);
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spi_unregister_master(master);
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return 0;
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}
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#ifdef CONFIG_PM
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static int bcm63xx_spi_suspend(struct device *dev)
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{
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struct spi_master *master =
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||||
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");
|
||||
Loading…
Reference in New Issue