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kernel-ark/arch/mips/mti-sead3/sead3-pic32-i2c-drv.c
Steven J. Hill 3070033a16 MIPS: Add core files for MIPS SEAD-3 development platform. 
More information about the SEAD-3 platform can be found at
<http://www.mips.com/products/development-kits/mips-sead-3/>
on MTI's site. Currently, the M14K family of cores is what
the SEAD-3 is utilised with.

Signed-off-by: Douglas Leung <douglas@mips.com>
Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Steven J. Hill <sjhill@mips.com>
2012-09-13 15:43:46 -05:00

436 lines
9.4 KiB
C
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/*
* 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);
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