1 files changed, 435 insertions, 0 deletions

diff --git a/arch/mips/mti-sead3/sead3-pic32-i2c-drv.c b/arch/mips/mti-sead3/sead3-pic32-i2c-drv.c
new file mode 100644
index 000000000000..46509b0a620d
--- /dev/null
+++ b/arch/mips/mti-sead3/sead3-pic32-i2c-drv.c
@@ -0,0 +1,435 @@
+/*
+ * 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/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/platform_device.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+
+#define PIC32_I2CxCON           0x0000
+#define PIC32_I2CxCONCLR        0x0004
+#define PIC32_I2CxCONSET        0x0008
+#define PIC32_I2CxCONINV        0x000C
+#define  I2CCON_ON              (1<<15)
+#define  I2CCON_FRZ             (1<<14)
+#define  I2CCON_SIDL            (1<<13)
+#define  I2CCON_SCLREL          (1<<12)
+#define  I2CCON_STRICT          (1<<11)
+#define  I2CCON_A10M            (1<<10)
+#define  I2CCON_DISSLW          (1<<9)
+#define  I2CCON_SMEN            (1<<8)
+#define  I2CCON_GCEN            (1<<7)
+#define  I2CCON_STREN           (1<<6)
+#define  I2CCON_ACKDT           (1<<5)
+#define  I2CCON_ACKEN           (1<<4)
+#define  I2CCON_RCEN            (1<<3)
+#define  I2CCON_PEN             (1<<2)
+#define  I2CCON_RSEN            (1<<1)
+#define  I2CCON_SEN             (1<<0)
+
+#define PIC32_I2CxSTAT          0x0010
+#define PIC32_I2CxSTATCLR       0x0014
+#define PIC32_I2CxSTATSET       0x0018
+#define PIC32_I2CxSTATINV       0x001C
+#define  I2CSTAT_ACKSTAT        (1<<15)
+#define  I2CSTAT_TRSTAT         (1<<14)
+#define  I2CSTAT_BCL            (1<<10)
+#define  I2CSTAT_GCSTAT         (1<<9)
+#define  I2CSTAT_ADD10          (1<<8)
+#define  I2CSTAT_IWCOL          (1<<7)
+#define  I2CSTAT_I2COV          (1<<6)
+#define  I2CSTAT_DA             (1<<5)
+#define  I2CSTAT_P              (1<<4)
+#define  I2CSTAT_S              (1<<3)
+#define  I2CSTAT_RW             (1<<2)
+#define  I2CSTAT_RBF            (1<<1)
+#define  I2CSTAT_TBF            (1<<0)
+
+#define PIC32_I2CxADD           0x0020
+#define PIC32_I2CxADDCLR        0x0024
+#define PIC32_I2CxADDSET        0x0028
+#define PIC32_I2CxADDINV        0x002C
+#define PIC32_I2CxMSK           0x0030
+#define PIC32_I2CxMSKCLR        0x0034
+#define PIC32_I2CxMSKSET        0x0038
+#define PIC32_I2CxMSKINV        0x003C
+#define PIC32_I2CxBRG           0x0040
+#define PIC32_I2CxBRGCLR        0x0044
+#define PIC32_I2CxBRGSET        0x0048
+#define PIC32_I2CxBRGINV        0x004C
+#define PIC32_I2CxTRN           0x0050
+#define PIC32_I2CxTRNCLR        0x0054
+#define PIC32_I2CxTRNSET        0x0058
+#define PIC32_I2CxTRNINV        0x005C
+#define PIC32_I2CxRCV           0x0060
+
+struct i2c_platform_data {
+        u32     base;
+        struct i2c_adapter adap;
+        u32     xfer_timeout;
+        u32     ack_timeout;
+        u32     ctl_timeout;
+};
+
+extern u32 pic32_bus_readl(u32 reg);
+extern void pic32_bus_writel(u32 val, u32 reg);
+
+static inline void
+StartI2C(struct i2c_platform_data *adap)
+{
+        pr_debug("StartI2C\n");
+        pic32_bus_writel(I2CCON_SEN, adap->base + PIC32_I2CxCONSET);
+}
+
+static inline void
+StopI2C(struct i2c_platform_data *adap)
+{
+        pr_debug("StopI2C\n");
+        pic32_bus_writel(I2CCON_PEN, adap->base + PIC32_I2CxCONSET);
+}
+
+static inline void
+AckI2C(struct i2c_platform_data *adap)
+{
+        pr_debug("AckI2C\n");
+        pic32_bus_writel(I2CCON_ACKDT, adap->base + PIC32_I2CxCONCLR);
+        pic32_bus_writel(I2CCON_ACKEN, adap->base + PIC32_I2CxCONSET);
+}
+
+static inline void
+NotAckI2C(struct i2c_platform_data *adap)
+{
+        pr_debug("NakI2C\n");
+        pic32_bus_writel(I2CCON_ACKDT, adap->base + PIC32_I2CxCONSET);
+        pic32_bus_writel(I2CCON_ACKEN, adap->base + PIC32_I2CxCONSET);
+}
+
+static inline int
+IdleI2C(struct i2c_platform_data *adap)
+{
+        int i;
+
+        pr_debug("IdleI2C\n");
+        for (i = 0; i < adap->ctl_timeout; i++) {
+                if (((pic32_bus_readl(adap->base + PIC32_I2CxCON) &
+                     (I2CCON_ACKEN | I2CCON_RCEN | I2CCON_PEN | I2CCON_RSEN |
+                      I2CCON_SEN)) == 0) &&
+                    ((pic32_bus_readl(adap->base + PIC32_I2CxSTAT) &
+                     (I2CSTAT_TRSTAT)) == 0))
+                        return 0;
+                udelay(1);
+        }
+        return -ETIMEDOUT;
+}
+
+static inline u32
+MasterWriteI2C(struct i2c_platform_data *adap, u32 byte)
+{
+        pr_debug("MasterWriteI2C\n");
+
+        pic32_bus_writel(byte, adap->base + PIC32_I2CxTRN);
+
+        return pic32_bus_readl(adap->base + PIC32_I2CxSTAT) & I2CSTAT_IWCOL;
+}
+
+static inline u32
+MasterReadI2C(struct i2c_platform_data *adap)
+{
+        pr_debug("MasterReadI2C\n");
+
+        pic32_bus_writel(I2CCON_RCEN, adap->base + PIC32_I2CxCONSET);
+
+        while (pic32_bus_readl(adap->base + PIC32_I2CxCON) & I2CCON_RCEN)
+                ;
+
+        pic32_bus_writel(I2CSTAT_I2COV, adap->base + PIC32_I2CxSTATCLR);
+
+        return pic32_bus_readl(adap->base + PIC32_I2CxRCV);
+}
+
+static int
+do_address(struct i2c_platform_data *adap, unsigned int addr, int rd)
+{
+        pr_debug("doaddress\n");
+
+        IdleI2C(adap);
+        StartI2C(adap);
+        IdleI2C(adap);
+
+        addr <<= 1;
+        if (rd)
+                addr |= 1;
+
+        if (MasterWriteI2C(adap, addr))
+                return -EIO;
+        IdleI2C(adap);
+        if (pic32_bus_readl(adap->base + PIC32_I2CxSTAT) & I2CSTAT_ACKSTAT)
+                return -EIO;
+        return 0;
+}
+
+static int
+i2c_read(struct i2c_platform_data *adap, unsigned char *buf,
+                    unsigned int len)
+{
+        int     i;
+        u32     data;
+
+        pr_debug("i2c_read\n");
+
+        i = 0;
+        while (i < len) {
+                data = MasterReadI2C(adap);
+                buf[i++] = data;
+                if (i < len)
+                        AckI2C(adap);
+                else
+                        NotAckI2C(adap);
+        }
+
+        StopI2C(adap);
+        IdleI2C(adap);
+        return 0;
+}
+
+static int
+i2c_write(struct i2c_platform_data *adap, unsigned char *buf,
+                     unsigned int len)
+{
+        int     i;
+        u32     data;
+
+        pr_debug("i2c_write\n");
+
+        i = 0;
+        while (i < len) {
+                data = buf[i];
+                if (MasterWriteI2C(adap, data))
+                        return -EIO;
+                IdleI2C(adap);
+                if (pic32_bus_readl(adap->base + PIC32_I2CxSTAT) &
+                    I2CSTAT_ACKSTAT)
+                        return -EIO;
+                i++;
+        }
+
+        StopI2C(adap);
+        IdleI2C(adap);
+        return 0;
+}
+
+static int
+platform_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
+{
+        struct i2c_platform_data *adap = i2c_adap->algo_data;
+        struct i2c_msg *p;
+        int i, err = 0;
+
+        pr_debug("platform_xfer\n");
+        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;
+                                }
+                        }
+                }
+                pr_debug("xfer%d: DevAddr: %04x Op:%s Data:%s\n", i, p->addr,
+                         (p->flags & I2C_M_RD) ? "Rd" : "Wr", buf);
+        }
+
+
+        for (i = 0; !err && i < num; i++) {
+                p = &msgs[i];
+                err = do_address(adap, p->addr, p->flags & I2C_M_RD);
+                if (err || !p->len)
+                        continue;
+                if (p->flags & I2C_M_RD)
+                        err = i2c_read(adap, p->buf, p->len);
+                else
+                        err = 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
+platform_func(struct i2c_adapter *adap)
+{
+        pr_debug("platform_algo\n");
+        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm platform_algo = {
+        .master_xfer    = platform_xfer,
+        .functionality  = platform_func,
+};
+
+static void i2c_platform_setup(struct i2c_platform_data *priv)
+{
+        pr_debug("i2c_platform_setup\n");
+
+        pic32_bus_writel(500, priv->base + PIC32_I2CxBRG);
+        pic32_bus_writel(I2CCON_ON, priv->base + PIC32_I2CxCONCLR);
+        pic32_bus_writel(I2CCON_ON, priv->base + PIC32_I2CxCONSET);
+        pic32_bus_writel((I2CSTAT_BCL | I2CSTAT_IWCOL),
+                (priv->base + PIC32_I2CxSTATCLR));
+}
+
+static void i2c_platform_disable(struct i2c_platform_data *priv)
+{
+        pr_debug("i2c_platform_disable\n");
+}
+
+static int __devinit
+i2c_platform_probe(struct platform_device *pdev)
+{
+        struct i2c_platform_data *priv;
+        struct resource *r;
+        int ret;
+
+        pr_debug("i2c_platform_probe\n");
+        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!r) {
+                ret = -ENODEV;
+                goto out;
+        }
+
+        priv = kzalloc(sizeof(struct i2c_platform_data), GFP_KERNEL);
+        if (!priv) {
+                ret = -ENOMEM;
+                goto out;
+        }
+
+        /* FIXME: need to allocate resource in PIC32 space */
+#if 0
+        priv->base = bus_request_region(r->start, resource_size(r),
+                                          pdev->name);
+#else
+        priv->base = r->start;
+#endif
+        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 = &platform_algo;
+        priv->adap.algo_data = priv;
+        priv->adap.dev.parent = &pdev->dev;
+        strlcpy(priv->adap.name, "PIC32 I2C", sizeof(priv->adap.name));
+
+        i2c_platform_setup(priv);
+
+        ret = i2c_add_numbered_adapter(&priv->adap);
+        if (ret == 0) {
+                platform_set_drvdata(pdev, priv);
+                return 0;
+        }
+
+        i2c_platform_disable(priv);
+
+out_mem:
+        kfree(priv);
+out:
+        return ret;
+}
+
+static int __devexit
+i2c_platform_remove(struct platform_device *pdev)
+{
+        struct i2c_platform_data *priv = platform_get_drvdata(pdev);
+
+        pr_debug("i2c_platform_remove\n");
+        platform_set_drvdata(pdev, NULL);
+        i2c_del_adapter(&priv->adap);
+        i2c_platform_disable(priv);
+        kfree(priv);
+        return 0;
+}
+
+#ifdef CONFIG_PM
+static int
+i2c_platform_suspend(struct platform_device *pdev, pm_message_t state)
+{
+        struct i2c_platform_data *priv = platform_get_drvdata(pdev);
+
+        dev_dbg(&pdev->dev, "i2c_platform_disable\n");
+        i2c_platform_disable(priv);
+
+        return 0;
+}
+
+static int
+i2c_platform_resume(struct platform_device *pdev)
+{
+        struct i2c_platform_data *priv = platform_get_drvdata(pdev);
+
+        dev_dbg(&pdev->dev, "i2c_platform_setup\n");
+        i2c_platform_setup(priv);
+
+        return 0;
+}
+#else
+#define i2c_platform_suspend    NULL
+#define i2c_platform_resume     NULL
+#endif
+
+static struct platform_driver i2c_platform_driver = {
+        .driver = {
+                .name   = "i2c_pic32",
+                .owner  = THIS_MODULE,
+        },
+        .probe          = i2c_platform_probe,
+        .remove         = __devexit_p(i2c_platform_remove),
+        .suspend        = i2c_platform_suspend,
+        .resume         = i2c_platform_resume,
+};
+
+static int __init
+i2c_platform_init(void)
+{
+        pr_debug("i2c_platform_init\n");
+        return platform_driver_register(&i2c_platform_driver);
+}
+
+static void __exit
+i2c_platform_exit(void)
+{
+        pr_debug("i2c_platform_exit\n");
+        platform_driver_unregister(&i2c_platform_driver);
+}
+
+MODULE_AUTHOR("Chris Dearman, MIPS Technologies INC.");
+MODULE_DESCRIPTION("PIC32 I2C driver");
+MODULE_LICENSE("GPL");
+
+module_init(i2c_platform_init);
+module_exit(i2c_platform_exit);