[brcm63xx] add bcm63xx_spi based on reading shared/opensource/flash/spiflash.c from the consumer releases, needs testing

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@14793 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 439 insertions, 0 deletions

diff --git a/target/linux/brcm63xx/files/drivers/spi/bcm63xx_spi.c b/target/linux/brcm63xx/files/drivers/spi/bcm63xx_spi.c
new file mode 100644
index 0000000000..449b1d5adf
--- /dev/null
+++ b/target/linux/brcm63xx/files/drivers/spi/bcm63xx_spi.c
@@ -0,0 +1,439 @@
+/*
+ * 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		"0.1.0"
+
+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		msg_fifo_size;
+	unsigned		rx_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)
+{
+	u16 val;
+
+	val = bcm_spi_readw(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, 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, 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(SPI_MSG_TAIL);
+        while ((tail < bs->msg_fifo_size) && (bs->remaining_bytes > 0)) {
+                if (bs->tx_ptr)
+                        bcm_spi_writeb(*bs->tx_ptr++, SPI_MSG_DATA);
+		else
+			bcm_spi_writeb(0, SPI_MSG_DATA); 
+                bs->remaining_bytes--;
+		tail = bcm_spi_readb(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_writeb(SPI_INTR_CMD_DONE, SPI_INT_MASK);
+	
+	/* Fill in the Message control register */
+	msg_ctl = bcm_spi_readb(SPI_MSG_CTL);
+	msg_ctl |= (t->len << SPI_BYTE_CNT_SHIFT);
+	msg_ctl |= (SPI_HD_R << SPI_MSG_TYPE_SHIFT);
+	bcm_spi_writeb(msg_ctl, SPI_MSG_CTL);
+	
+	/* Issue the transfer */
+	cmd = bcm_spi_readb(SPI_CMD);
+	cmd |= SPI_CMD_START_IMMEDIATE;
+	cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
+	bcm_spi_writeb(cmd, SPI_CMD);
+
+	wait_for_completion(&bs->done);	
+
+	/* Disable the CMD_DONE interrupt */
+	bcm_spi_writeb(~(SPI_INTR_CMD_DONE), 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(SPI_INT_STATUS);
+	bcm_writeb(SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
+
+	/* A tansfer completed */
+	if (intr & SPI_INTR_CMD_DONE) {
+		u8 rx_empty;
+	
+		rx_empty = bcm_spi_readb(SPI_ST);
+		/* Read out all the data */
+		while ((rx_empty & SPI_RX_EMPTY) == 0) {
+			u8 data;
+		
+			data = bcm_spi_readb(SPI_RX_DATA);
+			if (bs->rx_ptr)
+				*bs->rx_ptr++ = data;
+
+			rx_empty = bcm_spi_readb(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(SPI_CMD);
+			cmd |= SPI_CMD_START_IMMEDIATE;
+			cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
+			bcm_spi_writeb(cmd, 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;
+
+        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->msg_fifo_size = pdata->msg_fifo_size;
+	bs->rx_fifo_size = pdata->rx_fifo_size;
+
+	ret = request_irq(irq, bcm63xx_spi_interrupt, 0,
+				pdev->dev.bus_id, 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_writew(SPI_CMD_HARD_RESET, SPI_CMD);
+	bcm_spi_writeb(SPI_INTR_CLEAR_ALL, SPI_INT_MASK);
+	
+	dev_info(&pdev->dev, PFX " at 0x%08x (irq %d) %s\n",
+				r->start, irq, 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");