1 files changed, 405 insertions, 0 deletions
diff --git a/arch/mips/mti-sead3/sead3-i2c-drv.c b/arch/mips/mti-sead3/sead3-i2c-drv.c
new file mode 100644
index 000000000000..0375ee66bca3
--- /dev/null
+++ b/arch/mips/mti-sead3/sead3-i2c-drv.c
@@ -0,0 +1,405 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/platform_device.h>
+
+#define PIC32_I2CxCON		0x0000
+#define  PIC32_I2CCON_ON	(1<<15)
+#define  PIC32_I2CCON_ACKDT	(1<<5)
+#define  PIC32_I2CCON_ACKEN	(1<<4)
+#define  PIC32_I2CCON_RCEN	(1<<3)
+#define  PIC32_I2CCON_PEN	(1<<2)
+#define  PIC32_I2CCON_RSEN	(1<<1)
+#define  PIC32_I2CCON_SEN	(1<<0)
+#define PIC32_I2CxCONCLR	0x0004
+#define PIC32_I2CxCONSET	0x0008
+#define PIC32_I2CxSTAT		0x0010
+#define PIC32_I2CxSTATCLR	0x0014
+#define  PIC32_I2CSTAT_ACKSTAT	(1<<15)
+#define  PIC32_I2CSTAT_TRSTAT	(1<<14)
+#define  PIC32_I2CSTAT_BCL	(1<<10)
+#define  PIC32_I2CSTAT_IWCOL	(1<<7)
+#define  PIC32_I2CSTAT_I2COV	(1<<6)
+#define PIC32_I2CxBRG		0x0040
+#define PIC32_I2CxTRN		0x0050
+#define PIC32_I2CxRCV		0x0060
+
+static DEFINE_SPINLOCK(pic32_bus_lock);
+
+static void __iomem *bus_xfer   = (void __iomem *)0xbf000600;
+static void __iomem *bus_status = (void __iomem *)0xbf000060;
+
+#define DELAY()	udelay(100)
+
+static inline unsigned int ioready(void)
+{
+	return readl(bus_status) & 1;
+}
+
+static inline void wait_ioready(void)
+{
+	do { } while (!ioready());
+}
+
+static inline void wait_ioclear(void)
+{
+	do { } while (ioready());
+}
+
+static inline void check_ioclear(void)
+{
+	if (ioready()) {
+		do {
+			(void) readl(bus_xfer);
+			DELAY();
+		} while (ioready());
+	}
+}
+
+static u32 pic32_bus_readl(u32 reg)
+{
+	unsigned long flags;
+	u32 status, val;
+
+	spin_lock_irqsave(&pic32_bus_lock, flags);
+
+	check_ioclear();
+	writel((0x01 << 24) | (reg & 0x00ffffff), bus_xfer);
+	DELAY();
+	wait_ioready();
+	status = readl(bus_xfer);
+	DELAY();
+	val = readl(bus_xfer);
+	wait_ioclear();
+
+	spin_unlock_irqrestore(&pic32_bus_lock, flags);
+
+	return val;
+}
+
+static void pic32_bus_writel(u32 val, u32 reg)
+{
+	unsigned long flags;
+	u32 status;
+
+	spin_lock_irqsave(&pic32_bus_lock, flags);
+
+	check_ioclear();
+	writel((0x10 << 24) | (reg & 0x00ffffff), bus_xfer);
+	DELAY();
+	writel(val, bus_xfer);
+	DELAY();
+	wait_ioready();
+	status = readl(bus_xfer);
+	wait_ioclear();
+
+	spin_unlock_irqrestore(&pic32_bus_lock, flags);
+}
+
+struct pic32_i2c_platform_data {
+	u32	base;
+	struct i2c_adapter adap;
+	u32	xfer_timeout;
+	u32	ack_timeout;
+	u32	ctl_timeout;
+};
+
+static inline void pic32_i2c_start(struct pic32_i2c_platform_data *adap)
+{
+	pic32_bus_writel(PIC32_I2CCON_SEN, adap->base + PIC32_I2CxCONSET);
+}
+
+static inline void pic32_i2c_stop(struct pic32_i2c_platform_data *adap)
+{
+	pic32_bus_writel(PIC32_I2CCON_PEN, adap->base + PIC32_I2CxCONSET);
+}
+
+static inline void pic32_i2c_ack(struct pic32_i2c_platform_data *adap)
+{
+	pic32_bus_writel(PIC32_I2CCON_ACKDT, adap->base + PIC32_I2CxCONCLR);
+	pic32_bus_writel(PIC32_I2CCON_ACKEN, adap->base + PIC32_I2CxCONSET);
+}
+
+static inline void pic32_i2c_nack(struct pic32_i2c_platform_data *adap)
+{
+	pic32_bus_writel(PIC32_I2CCON_ACKDT, adap->base + PIC32_I2CxCONSET);
+	pic32_bus_writel(PIC32_I2CCON_ACKEN, adap->base + PIC32_I2CxCONSET);
+}
+
+static inline int pic32_i2c_idle(struct pic32_i2c_platform_data *adap)
+{
+	int i;
+
+	for (i = 0; i < adap->ctl_timeout; i++) {
+		if (((pic32_bus_readl(adap->base + PIC32_I2CxCON) &
+		      (PIC32_I2CCON_ACKEN | PIC32_I2CCON_RCEN |
+		       PIC32_I2CCON_PEN | PIC32_I2CCON_RSEN |
+		       PIC32_I2CCON_SEN)) == 0) &&
+		    ((pic32_bus_readl(adap->base + PIC32_I2CxSTAT) &
+		      (PIC32_I2CSTAT_TRSTAT)) == 0))
+			return 0;
+		udelay(1);
+	}
+	return -ETIMEDOUT;
+}
+
+static inline u32 pic32_i2c_master_write(struct pic32_i2c_platform_data *adap,
+		u32 byte)
+{
+	pic32_bus_writel(byte, adap->base + PIC32_I2CxTRN);
+	return pic32_bus_readl(adap->base + PIC32_I2CxSTAT) &
+			PIC32_I2CSTAT_IWCOL;
+}
+
+static inline u32 pic32_i2c_master_read(struct pic32_i2c_platform_data *adap)
+{
+	pic32_bus_writel(PIC32_I2CCON_RCEN, adap->base + PIC32_I2CxCONSET);
+	while (pic32_bus_readl(adap->base + PIC32_I2CxCON) & PIC32_I2CCON_RCEN)
+		;
+	pic32_bus_writel(PIC32_I2CSTAT_I2COV, adap->base + PIC32_I2CxSTATCLR);
+	return pic32_bus_readl(adap->base + PIC32_I2CxRCV);
+}
+
+static int pic32_i2c_address(struct pic32_i2c_platform_data *adap,
+		unsigned int addr, int rd)
+{
+	pic32_i2c_idle(adap);
+	pic32_i2c_start(adap);
+	pic32_i2c_idle(adap);
+
+	addr <<= 1;
+	if (rd)
+		addr |= 1;
+
+	if (pic32_i2c_master_write(adap, addr))
+		return -EIO;
+	pic32_i2c_idle(adap);
+	if (pic32_bus_readl(adap->base + PIC32_I2CxSTAT) &
+			PIC32_I2CSTAT_ACKSTAT)
+		return -EIO;
+	return 0;
+}
+
+static int sead3_i2c_read(struct pic32_i2c_platform_data *adap,
+		unsigned char *buf, unsigned int len)
+{
+	u32 data;
+	int i;
+
+	i = 0;
+	while (i < len) {
+		data = pic32_i2c_master_read(adap);
+		buf[i++] = data;
+		if (i < len)
+			pic32_i2c_ack(adap);
+		else
+			pic32_i2c_nack(adap);
+	}
+
+	pic32_i2c_stop(adap);
+	pic32_i2c_idle(adap);
+	return 0;
+}
+
+static int sead3_i2c_write(struct pic32_i2c_platform_data *adap,
+		unsigned char *buf, unsigned int len)
+{
+	int i;
+	u32 data;
+
+	i = 0;
+	while (i < len) {
+		data = buf[i];
+		if (pic32_i2c_master_write(adap, data))
+			return -EIO;
+		pic32_i2c_idle(adap);
+		if (pic32_bus_readl(adap->base + PIC32_I2CxSTAT) &
+					PIC32_I2CSTAT_ACKSTAT)
+			return -EIO;
+		i++;
+	}
+
+	pic32_i2c_stop(adap);
+	pic32_i2c_idle(adap);
+	return 0;
+}
+
+static int sead3_pic32_platform_xfer(struct i2c_adapter *i2c_adap,
+		struct i2c_msg *msgs, int num)
+{
+	struct pic32_i2c_platform_data *adap = i2c_adap->algo_data;
+	struct i2c_msg *p;
+	int i, err = 0;
+
+	for (i = 0; i < num; i++) {
+#define __BUFSIZE 80
+		int ii;
+		static char buf[__BUFSIZE];
+		char *b = buf;
+
+		p = &msgs[i];
+		b += sprintf(buf, " [%d bytes]", p->len);
+		if ((p->flags & I2C_M_RD) == 0) {
+			for (ii = 0; ii < p->len; ii++) {
+				if (b < &buf[__BUFSIZE-4]) {
+					b += sprintf(b, " %02x", p->buf[ii]);
+				} else {
+					strcat(b, "...");
+					break;
+				}
+			}
+		}
+	}
+
+	for (i = 0; !err && i < num; i++) {
+		p = &msgs[i];
+		err = pic32_i2c_address(adap, p->addr, p->flags & I2C_M_RD);
+		if (err || !p->len)
+			continue;
+		if (p->flags & I2C_M_RD)
+			err = sead3_i2c_read(adap, p->buf, p->len);
+		else
+			err = sead3_i2c_write(adap, p->buf, p->len);
+	}
+
+	/* Return the number of messages processed, or the error code. */
+	if (err == 0)
+		err = num;
+
+	return err;
+}
+
+static u32 sead3_pic32_platform_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm sead3_platform_algo = {
+	.master_xfer	= sead3_pic32_platform_xfer,
+	.functionality	= sead3_pic32_platform_func,
+};
+
+static void sead3_i2c_platform_setup(struct pic32_i2c_platform_data *priv)
+{
+	pic32_bus_writel(500, priv->base + PIC32_I2CxBRG);
+	pic32_bus_writel(PIC32_I2CCON_ON, priv->base + PIC32_I2CxCONCLR);
+	pic32_bus_writel(PIC32_I2CCON_ON, priv->base + PIC32_I2CxCONSET);
+	pic32_bus_writel(PIC32_I2CSTAT_BCL | PIC32_I2CSTAT_IWCOL,
+		priv->base + PIC32_I2CxSTATCLR);
+}
+
+static int __devinit sead3_i2c_platform_probe(struct platform_device *pdev)
+{
+	struct pic32_i2c_platform_data *priv;
+	struct resource *r;
+	int ret;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!r) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	priv = kzalloc(sizeof(struct pic32_i2c_platform_data), GFP_KERNEL);
+	if (!priv) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	priv->base = r->start;
+	if (!priv->base) {
+		ret = -EBUSY;
+		goto out_mem;
+	}
+
+	priv->xfer_timeout = 200;
+	priv->ack_timeout = 200;
+	priv->ctl_timeout = 200;
+
+	priv->adap.nr = pdev->id;
+	priv->adap.algo = &sead3_platform_algo;
+	priv->adap.algo_data = priv;
+	priv->adap.dev.parent = &pdev->dev;
+	strlcpy(priv->adap.name, "SEAD3 PIC32", sizeof(priv->adap.name));
+
+	sead3_i2c_platform_setup(priv);
+
+	ret = i2c_add_numbered_adapter(&priv->adap);
+	if (ret == 0) {
+		platform_set_drvdata(pdev, priv);
+		return 0;
+	}
+
+out_mem:
+	kfree(priv);
+out:
+	return ret;
+}
+
+static int __devexit sead3_i2c_platform_remove(struct platform_device *pdev)
+{
+	struct pic32_i2c_platform_data *priv = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+	i2c_del_adapter(&priv->adap);
+	kfree(priv);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int sead3_i2c_platform_suspend(struct platform_device *pdev,
+		pm_message_t state)
+{
+	dev_dbg(&pdev->dev, "i2c_platform_disable\n");
+	return 0;
+}
+
+static int sead3_i2c_platform_resume(struct platform_device *pdev)
+{
+	struct pic32_i2c_platform_data *priv = platform_get_drvdata(pdev);
+
+	dev_dbg(&pdev->dev, "sead3_i2c_platform_setup\n");
+	sead3_i2c_platform_setup(priv);
+
+	return 0;
+}
+#else
+#define sead3_i2c_platform_suspend	NULL
+#define sead3_i2c_platform_resume	NULL
+#endif
+
+static struct platform_driver sead3_i2c_platform_driver = {
+	.driver = {
+		.name	= "sead3-i2c",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= sead3_i2c_platform_probe,
+	.remove		= __devexit_p(sead3_i2c_platform_remove),
+	.suspend	= sead3_i2c_platform_suspend,
+	.resume		= sead3_i2c_platform_resume,
+};
+
+static int __init sead3_i2c_platform_init(void)
+{
+	return platform_driver_register(&sead3_i2c_platform_driver);
+}
+module_init(sead3_i2c_platform_init);
+
+static void __exit sead3_i2c_platform_exit(void)
+{
+	platform_driver_unregister(&sead3_i2c_platform_driver);
+}
+module_exit(sead3_i2c_platform_exit);
+
+MODULE_AUTHOR("Chris Dearman, MIPS Technologies INC.");
+MODULE_DESCRIPTION("SEAD3 PIC32 I2C driver");
+MODULE_LICENSE("GPL");