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Diffstat (limited to 'arch/mips/mti-sead3/sead3-i2c-drv.c')
-rw-r--r--arch/mips/mti-sead3/sead3-i2c-drv.c405
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");