Add an SPI master driver for the OMAP2 McSPI controller

Signed-off-by: Juha Yrjölä <juha.yrjola@nokia.com>

drivers/spi/Kconfig

@@ -85,6 +85,12 @@ config SPI_BUTTERFLY
 	  inexpensive battery powered microcontroller evaluation board.
 	  This same cable can be used to flash new firmware.
 
+config SPI_OMAP24XX
+	bool "McSPI driver for OMAP24xx"
+	depends on SPI_MASTER && ARCH_OMAP24XX
+	help
+	  SPI master controller for OMAP24xx McSPI modules.
+
 #
 # Add new SPI master controllers in alphabetical order above this line
 #

drivers/spi/Makefile

@@ -13,6 +13,7 @@ obj-$(CONFIG_SPI_MASTER)		+= spi.o
 # SPI master controller drivers (bus)
 obj-$(CONFIG_SPI_BITBANG)		+= spi_bitbang.o
 obj-$(CONFIG_SPI_BUTTERFLY)		+= spi_butterfly.o
+obj-$(CONFIG_SPI_OMAP24XX)		+= omap2_mcspi.o
 # 	... add above this line ...
 
 # SPI protocol drivers (device/link on bus)

drivers/spi/omap2_mcspi.c

+/*
+ * OMAP2 McSPI controller driver
+ *
+ * Copyright (C) 2005, 2006 Nokia Corporation
+ * Author: Samuel Ortiz <samuel.ortiz@nokia.com> and
+ *         Juha Yrjl <juha.yrjola@nokia.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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+
+#include <linux/spi/spi.h>
+
+#include <asm/io.h>
+#include <asm/arch/mcspi.h>
+
+#define OMAP2_MCSPI_MAX_FREQ		48000000
+
+#define OMAP2_MCSPI_REVISION		0x00
+#define OMAP2_MCSPI_SYSCONFIG		0x10
+#define OMAP2_MCSPI_SYSSTATUS		0x14
+#define OMAP2_MCSPI_IRQSTATUS		0x18
+#define OMAP2_MCSPI_IRQENABLE		0x1c
+#define OMAP2_MCSPI_WAKEUPENABLE	0x20
+#define OMAP2_MCSPI_SYST		0x24
+#define OMAP2_MCSPI_MODULCTRL		0x28
+#define OMAP2_MCSPI_CHCONF0		0x2c
+#define OMAP2_MCSPI_CHSTAT0		0x30
+#define OMAP2_MCSPI_CHCTRL0		0x34
+#define OMAP2_MCSPI_TX0			0x38
+#define OMAP2_MCSPI_RX0			0x3c
+
+#define OMAP2_MCSPI_SYSCONFIG_SOFTRESET	(1 << 1)
+
+#define OMAP2_MCSPI_SYSSTATUS_RESETDONE	(1 << 0)
+
+#define OMAP2_MCSPI_MODULCTRL_SINGLE	(1 << 0)
+#define OMAP2_MCSPI_MODULCTRL_MS	(1 << 2)
+#define OMAP2_MCSPI_MODULCTRL_STEST	(1 << 3)
+
+#define OMAP2_MCSPI_CHCONF_PHA		(1 << 0)
+#define OMAP2_MCSPI_CHCONF_POL		(1 << 1)
+#define OMAP2_MCSPI_CHCONF_CLKD_MASK	(0x0f << 2)
+#define OMAP2_MCSPI_CHCONF_EPOL		(1 << 6)
+#define OMAP2_MCSPI_CHCONF_WL_MASK	(0x1f << 7)
+#define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY	(0x01 << 12)
+#define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY	(0x02 << 12)
+#define OMAP2_MCSPI_CHCONF_TRM_MASK	(0x03 << 12)
+#define OMAP2_MCSPI_CHCONF_DPE0		(1 << 16)
+#define OMAP2_MCSPI_CHCONF_DPE1		(1 << 17)
+#define OMAP2_MCSPI_CHCONF_IS		(1 << 18)
+#define OMAP2_MCSPI_CHCONF_TURBO	(1 << 19)
+#define OMAP2_MCSPI_CHCONF_FORCE	(1 << 20)
+
+
+#define OMAP2_MCSPI_CHSTAT_RXS		(1 << 0)
+#define OMAP2_MCSPI_CHSTAT_TXS		(1 << 1)
+#define OMAP2_MCSPI_CHSTAT_EOT		(1 << 2)
+
+#define OMAP2_MCSPI_CHCTRL_EN		(1 << 0)
+
+struct omap2_mcspi {
+	struct tasklet_struct   tasklet;
+	spinlock_t		lock;
+	struct list_head	msg_queue;
+	struct spi_master	*master;
+};
+
+struct omap2_mcspi_cs {
+	u8 transmit_mode;
+};
+
+#define MOD_REG_BIT(val, mask, set) do { \
+	if (set) \
+		val |= mask; \
+	else \
+		val &= ~mask; \
+} while(0)
+
+
+#define MASTER_PDATA(master) (struct omap2_mcspi_platform_config *)((master)->cdev.dev->platform_data)
+
+static inline void mcspi_write_reg(const struct spi_master *master,
+				   int idx, u32 val)
+{
+	struct omap2_mcspi_platform_config *pdata = MASTER_PDATA(master);
+
+	__raw_writel(val, pdata->base + idx);
+}
+
+static inline u32 mcspi_read_reg(const struct spi_master *master,
+				 int idx)
+{
+	struct omap2_mcspi_platform_config *pdata = MASTER_PDATA(master);
+
+	return __raw_readl(pdata->base + idx);
+}
+
+static inline void mcspi_write_cs_reg(const struct spi_device *spi,
+				      int idx, u32 val)
+{
+	struct omap2_mcspi_platform_config *pdata = MASTER_PDATA(spi->master);
+
+	__raw_writel(val, pdata->base + spi->chip_select * 0x14 + idx);
+}
+
+static inline u32 mcspi_read_cs_reg(const struct spi_device *spi,
+				    int idx)
+{
+	struct omap2_mcspi_platform_config *pdata = MASTER_PDATA(spi->master);
+
+	return __raw_readl(pdata->base + spi->chip_select * 0x14 + idx);
+}
+
+static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
+{
+	u32 l;
+
+	l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
+	MOD_REG_BIT(l, OMAP2_MCSPI_CHCTRL_EN, enable);
+	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, l);
+}
+
+static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
+{
+	u32 l;
+
+	l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
+	MOD_REG_BIT(l, OMAP2_MCSPI_CHCONF_FORCE, cs_active);
+	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
+}
+
+static void omap2_mcspi_set_master_mode(struct spi_device *spi, int single_channel)
+{
+	u32 l;
+
+	/* Need reset when switching from slave mode */
+	l = mcspi_read_reg(spi->master, OMAP2_MCSPI_MODULCTRL);
+	MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_STEST, 0);
+	MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_MS, 0);
+	MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_SINGLE, single_channel);
+	mcspi_write_reg(spi->master, OMAP2_MCSPI_MODULCTRL, l);
+}
+
+static void omap2_mcspi_txrx(struct spi_device *spi, struct spi_transfer *xfer)
+{
+	unsigned int		count, c;
+	u32                     l;
+	unsigned long		base, tx_reg, rx_reg, chstat_reg;
+
+	count = xfer->len;
+	c = count;
+
+	l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
+	l &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
+	if (xfer->tx_buf == NULL)
+		l |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
+	else if (xfer->rx_buf == NULL)
+		l |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
+	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
+
+	omap2_mcspi_set_enable(spi, 1);
+
+	/* We store the pre-calculated register addresses on stack to speed
+	 * up the transfer loop. */
+	base = (MASTER_PDATA(spi->master))->base + spi->chip_select * 0x14;
+	tx_reg		= base + OMAP2_MCSPI_TX0;
+	rx_reg		= base + OMAP2_MCSPI_RX0;
+	chstat_reg	= base + OMAP2_MCSPI_CHSTAT0;
+
+	/* RX_ONLY mode needs dummy data in TX reg */
+	if (xfer->tx_buf == NULL)
+		__raw_writel(0, tx_reg);
+
+	if (spi->bits_per_word <= 8) {
+		u8		*rx;
+		const u8	*tx;
+
+		rx = xfer->rx_buf;
+		tx = xfer->tx_buf;
+
+		while (c--) {
+			if (tx != NULL) {
+				while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_TXS));
+				__raw_writel(*tx, tx_reg);
+			}
+			if (rx != NULL) {
+				while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_RXS));
+				if (c == 0 && tx == NULL)
+					omap2_mcspi_set_enable(spi, 0);
+				*rx++ = __raw_readl(rx_reg);
+			}
+		}
+	} else if (spi->bits_per_word <= 16) {
+		u16		*rx;
+		const u16	*tx;
+
+		rx = xfer->rx_buf;
+		tx = xfer->tx_buf;
+		c >>= 1;
+		while (c--) {
+			if (tx != NULL) {
+				while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_TXS));
+				__raw_writel(*tx++, tx_reg);
+			}
+			if (rx != NULL) {
+				while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_RXS));
+				if (c == 0 && tx == NULL)
+					omap2_mcspi_set_enable(spi, 0);
+				*rx++ = __raw_readl(rx_reg);
+			}
+		}
+	} else if (spi->bits_per_word <= 32) {
+		u32		*rx;
+		const u32	*tx;
+
+		rx = xfer->rx_buf;
+		tx = xfer->tx_buf;
+		c >>= 2;
+		while (c--) {
+			if (tx != NULL) {
+				while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_TXS));
+				__raw_writel(*tx++, tx_reg);
+			}
+			if (rx != NULL) {
+				while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_RXS));
+				if (c == 0 && tx == NULL)
+					omap2_mcspi_set_enable(spi, 0);
+				*rx++ = __raw_readl(rx_reg);
+			}
+		}
+	}
+
+	if (xfer->tx_buf != NULL) {
+		while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_TXS));
+		while (!(__raw_readl(chstat_reg) & OMAP2_MCSPI_CHSTAT_EOT));
+		omap2_mcspi_set_enable(spi, 0);
+	}
+}
+
+static int omap2_mcspi_setup(struct spi_device *spi)
+{
+	struct omap2_mcspi_cs *cs = spi->controller_state;
+	struct omap2_mcspi_device_config *conf;
+	u32 l = 0, div = 0;
+	u8 word_len = spi->bits_per_word;
+
+	if (!word_len)
+		return 0;
+
+	if (!cs) {
+		cs = kzalloc(sizeof *cs, SLAB_KERNEL);
+		if (!cs)
+			return -ENOMEM;
+		spi->controller_state = cs;
+	}
+
+	if (spi->bits_per_word > 32)
+		return -EINVAL;
+
+	conf = (struct omap2_mcspi_device_config *) spi->controller_data;
+
+	if (conf->single_channel == 1)
+		omap2_mcspi_set_master_mode(spi, 1);
+	else
+		omap2_mcspi_set_master_mode(spi, 0);
+
+	if (spi->max_speed_hz) {
+		while (div <= 15 && (OMAP2_MCSPI_MAX_FREQ / (1 << div)) > spi->max_speed_hz)
+			div++;
+	} else
+		div = 15;
+
+	if (spi->chip_select > 3 ||
+	    word_len < 4 || word_len > 32 ||
+	    div > 15) {
+		dev_err(&spi->dev, "Invalid McSPI channel setting\n");
+		return -EINVAL;
+	}
+
+	l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
+	l &= ~OMAP2_MCSPI_CHCONF_IS;
+	l &= ~OMAP2_MCSPI_CHCONF_DPE1;
+	l |= OMAP2_MCSPI_CHCONF_DPE0;
+	l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
+	l |= (word_len - 1) << 7;
+	if (!(spi->mode & SPI_CS_HIGH))
+		l |= OMAP2_MCSPI_CHCONF_EPOL;
+	l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
+	l |= div << 2;
+	if (spi->mode & SPI_CPOL)
+		l |= OMAP2_MCSPI_CHCONF_POL;
+	if (spi->mode & SPI_CPHA)
+		l |= OMAP2_MCSPI_CHCONF_PHA;
+	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
+
+	return 0;
+}
+
+static void omap2_mcspi_cleanup(const struct spi_device *spi)
+{
+	if (spi->controller_state != NULL)
+		kfree(spi->controller_state);
+}
+
+
+static void omap2_mcspi_work(unsigned long arg)
+{
+	struct omap2_mcspi	*mcspi = (struct omap2_mcspi *) arg;
+	unsigned long		flags;
+
+	spin_lock_irqsave(&mcspi->lock, flags);
+	while (!list_empty(&mcspi->msg_queue)) {
+		struct spi_message		*m;
+		struct spi_device		*spi;
+		struct spi_transfer		*t = NULL;
+		int				cs_active;
+		struct omap2_mcspi_device_config *conf;
+		struct omap2_mcspi_cs		*cs;
+		int status = 0;
+
+		m = container_of(mcspi->msg_queue.next, struct spi_message,
+				 queue);
+
+		list_del_init(&m->queue);
+		spin_unlock_irqrestore(&mcspi->lock, flags);
+
+		spi = m->spi;
+		conf = (struct omap2_mcspi_device_config *) spi->controller_data;
+		cs = (struct omap2_mcspi_cs *) spi->controller_state;
+
+		omap2_mcspi_force_cs(spi, 1);
+		cs_active = 1;
+
+		list_for_each_entry(t, &m->transfers, transfer_list) {
+			if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
+				status = -EINVAL;
+				break;
+			}
+
+			if (!cs_active) {
+				omap2_mcspi_force_cs(spi, 1);
+				cs_active = 1;
+			}
+
+			omap2_mcspi_txrx(spi, t);
+
+			if (t->cs_change) {
+				omap2_mcspi_force_cs(spi, 0);
+				cs_active = 0;
+			}
+		}
+
+		if (cs_active)
+			omap2_mcspi_force_cs(spi, 0);
+
+		m->status = status;
+		m->complete(m->context);
+
+		spin_lock_irqsave(&mcspi->lock, flags);
+	}
+	spin_unlock_irqrestore(&mcspi->lock, flags);
+}
+
+static int omap2_mcspi_transfer(struct spi_device *spi, struct spi_message *m)
+{
+	struct omap2_mcspi	*mcspi;
+	unsigned long		flags;
+
+	m->actual_length = 0;
+	m->status = 0;
+
+	mcspi = class_get_devdata(&spi->master->cdev);
+
+	spin_lock_irqsave(&mcspi->lock, flags);
+	list_add_tail(&m->queue, &mcspi->msg_queue);
+	spin_unlock_irqrestore(&mcspi->lock, flags);
+
+	tasklet_hi_schedule(&mcspi->tasklet);
+
+	return 0;
+}
+
+static int __devinit omap2_mcspi_reset(struct spi_master *master)
+{
+#if 0
+	mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG,
+			OMAP2_MCSPI_SYSCONFIG_SOFTRESET);
+	while (!(mcspi_read_reg(master, OMAP2_MCSPI_SYSSTATUS) & OMAP2_MCSPI_SYSSTATUS_RESETDONE));
+#else
+	return 0;
+#endif
+}
+
+static int __devinit omap2_mcspi_probe(struct platform_device *pdev)
+{
+	struct spi_master		*master;
+	struct omap2_mcspi_platform_config *pdata = pdev->dev.platform_data;
+	struct omap2_mcspi		*mcspi;
+	int				status = 0;
+
+	if (!pdata)
+		return -EINVAL;
+
+	master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
+	if (!master) {
+		dev_err(&pdev->dev, "master allocation failed\n");
+		return -ENOMEM;
+	}
+
+	if (pdev->id != -1)
+		master->bus_num = pdev->id;
+
+	master->setup = omap2_mcspi_setup;
+	master->transfer = omap2_mcspi_transfer;
+	master->cleanup = omap2_mcspi_cleanup;
+	master->num_chipselect = pdata->num_cs;
+
+	if (class_device_get(&master->cdev) == NULL) {
+		dev_err(&pdev->dev, "no master->cdev");
+		status = -ENOMEM;
+		goto err0;
+	}
+
+	dev_set_drvdata(&pdev->dev, master);
+
+	mcspi = class_get_devdata(&master->cdev);
+	mcspi->master = master;
+
+	tasklet_init(&mcspi->tasklet, omap2_mcspi_work, (unsigned long) mcspi);
+
+	spin_lock_init(&mcspi->lock);
+	INIT_LIST_HEAD(&mcspi->msg_queue);
+
+	if (omap2_mcspi_reset(master) < 0)
+                goto err1;
+
+	status = spi_register_master(master);
+	if (status < 0)
+		goto err1;
+
+	return status;
+
+ err1:
+	class_device_put(&master->cdev);
+ err0:
+	return status;
+}
+
+static int __devexit omap2_mcspi_remove(struct platform_device *pdev)
+{
+	struct spi_master		*master;
+
+	master = dev_get_drvdata(&pdev->dev);
+
+	spi_unregister_master(master);
+
+	return 0;
+}
+
+struct platform_driver omap2_mcspi_driver = {
+	.driver = {
+		.name =		"omap2_mcspi",
+		.owner =	THIS_MODULE,
+	},
+	.probe =	omap2_mcspi_probe,
+	.remove =	__devexit_p(omap2_mcspi_remove),
+};
+EXPORT_SYMBOL_GPL(omap2_mcspi_driver);
+
+
+static int __init omap2_mcspi_init(void)
+{
+	printk(KERN_INFO "OMAP24xx McSPI driver initializing\n");
+	return platform_driver_register(&omap2_mcspi_driver);
+}
+subsys_initcall(omap2_mcspi_init);
+
+static void __exit omap2_mcspi_exit(void)
+{
+	platform_driver_unregister(&omap2_mcspi_driver);
+}
+module_exit(omap2_mcspi_exit);
+
+MODULE_LICENSE("GPL");

include/asm-arm/arch-omap/mcspi.h

+#ifndef _OMAP2_MCSPI_H
+#define _OMAP2_MCSPI_H
+
+struct omap2_mcspi_platform_config {
+	unsigned long	base;
+	unsigned short	num_cs;
+};
+
+struct omap2_mcspi_device_config {
+	unsigned turbo_mode:1;
+
+	/* Do we want one channel enabled at the same time? */
+	unsigned single_channel:1;
+};
+
+#endif