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linux/drivers/i2c/busses/i2c-ocores.c
Tim Schmielau cd354f1ae7 [PATCH] remove many unneeded #includes of sched.h 
After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there.  Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.

To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.

Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm.  I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).

Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:54 -08:00

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/*
* i2c-ocores.c: I2C bus driver for OpenCores I2C controller
* (http://www.opencores.org/projects.cgi/web/i2c/overview).
*
* Peter Korsgaard <jacmet@sunsite.dk>
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/wait.h>
#include <linux/i2c-ocores.h>
#include <asm/io.h>
struct ocores_i2c {
void __iomem *base;
int regstep;
wait_queue_head_t wait;
struct i2c_adapter adap;
struct i2c_msg *msg;
int pos;
int nmsgs;
int state; /* see STATE_ */
};
/* registers */
#define OCI2C_PRELOW 0
#define OCI2C_PREHIGH 1
#define OCI2C_CONTROL 2
#define OCI2C_DATA 3
#define OCI2C_CMD 4 /* write only */
#define OCI2C_STATUS 4 /* read only, same address as OCI2C_CMD */
#define OCI2C_CTRL_IEN 0x40
#define OCI2C_CTRL_EN 0x80
#define OCI2C_CMD_START 0x91
#define OCI2C_CMD_STOP 0x41
#define OCI2C_CMD_READ 0x21
#define OCI2C_CMD_WRITE 0x11
#define OCI2C_CMD_READ_ACK 0x21
#define OCI2C_CMD_READ_NACK 0x29
#define OCI2C_CMD_IACK 0x01
#define OCI2C_STAT_IF 0x01
#define OCI2C_STAT_TIP 0x02
#define OCI2C_STAT_ARBLOST 0x20
#define OCI2C_STAT_BUSY 0x40
#define OCI2C_STAT_NACK 0x80
#define STATE_DONE 0
#define STATE_START 1
#define STATE_WRITE 2
#define STATE_READ 3
#define STATE_ERROR 4
static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value)
{
iowrite8(value, i2c->base + reg * i2c->regstep);
}
static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg)
{
return ioread8(i2c->base + reg * i2c->regstep);
}
static void ocores_process(struct ocores_i2c *i2c)
{
struct i2c_msg *msg = i2c->msg;
u8 stat = oc_getreg(i2c, OCI2C_STATUS);
if ((i2c->state == STATE_DONE) || (i2c->state == STATE_ERROR)) {
/* stop has been sent */
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK);
wake_up(&i2c->wait);
return;
}
/* error? */
if (stat & OCI2C_STAT_ARBLOST) {
i2c->state = STATE_ERROR;
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP);
return;
}
if ((i2c->state == STATE_START) || (i2c->state == STATE_WRITE)) {
i2c->state =
(msg->flags & I2C_M_RD) ? STATE_READ : STATE_WRITE;
if (stat & OCI2C_STAT_NACK) {
i2c->state = STATE_ERROR;
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP);
return;
}
} else
msg->buf[i2c->pos++] = oc_getreg(i2c, OCI2C_DATA);
/* end of msg? */
if (i2c->pos == msg->len) {
i2c->nmsgs--;
i2c->msg++;
i2c->pos = 0;
msg = i2c->msg;
if (i2c->nmsgs) { /* end? */
/* send start? */
if (!(msg->flags & I2C_M_NOSTART)) {
u8 addr = (msg->addr << 1);
if (msg->flags & I2C_M_RD)
addr |= 1;
i2c->state = STATE_START;
oc_setreg(i2c, OCI2C_DATA, addr);
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_START);
return;
} else
i2c->state = (msg->flags & I2C_M_RD)
? STATE_READ : STATE_WRITE;
} else {
i2c->state = STATE_DONE;
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP);
return;
}
}
if (i2c->state == STATE_READ) {
oc_setreg(i2c, OCI2C_CMD, i2c->pos == (msg->len-1) ?
OCI2C_CMD_READ_NACK : OCI2C_CMD_READ_ACK);
} else {
oc_setreg(i2c, OCI2C_DATA, msg->buf[i2c->pos++]);
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_WRITE);
}
}
static irqreturn_t ocores_isr(int irq, void *dev_id)
{
struct ocores_i2c *i2c = dev_id;
ocores_process(i2c);
return IRQ_HANDLED;
}
static int ocores_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
struct ocores_i2c *i2c = i2c_get_adapdata(adap);
i2c->msg = msgs;
i2c->pos = 0;
i2c->nmsgs = num;
i2c->state = STATE_START;
oc_setreg(i2c, OCI2C_DATA,
(i2c->msg->addr << 1) |
((i2c->msg->flags & I2C_M_RD) ? 1:0));
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_START);
if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) ||
(i2c->state == STATE_DONE), HZ))
return (i2c->state == STATE_DONE) ? num : -EIO;
else
return -ETIMEDOUT;
}
static void ocores_init(struct ocores_i2c *i2c,
struct ocores_i2c_platform_data *pdata)
{
int prescale;
u8 ctrl = oc_getreg(i2c, OCI2C_CONTROL);
/* make sure the device is disabled */
oc_setreg(i2c, OCI2C_CONTROL, ctrl & ~(OCI2C_CTRL_EN|OCI2C_CTRL_IEN));
prescale = (pdata->clock_khz / (5*100)) - 1;
oc_setreg(i2c, OCI2C_PRELOW, prescale & 0xff);
oc_setreg(i2c, OCI2C_PREHIGH, prescale >> 8);
/* Init the device */
oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK);
oc_setreg(i2c, OCI2C_CONTROL, ctrl | OCI2C_CTRL_IEN | OCI2C_CTRL_EN);
}
static u32 ocores_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
static const struct i2c_algorithm ocores_algorithm = {
.master_xfer = ocores_xfer,
.functionality = ocores_func,
};
static struct i2c_adapter ocores_adapter = {
.owner = THIS_MODULE,
.name = "i2c-ocores",
.class = I2C_CLASS_HWMON,
.algo = &ocores_algorithm,
};
static int __devinit ocores_i2c_probe(struct platform_device *pdev)
{
struct ocores_i2c *i2c;
struct ocores_i2c_platform_data *pdata;
struct resource *res, *res2;
int ret;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENODEV;
res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!res2)
return -ENODEV;
pdata = (struct ocores_i2c_platform_data*) pdev->dev.platform_data;
if (!pdata)
return -ENODEV;
i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
if (!i2c)
return -ENOMEM;
if (!request_mem_region(res->start, res->end - res->start + 1,
pdev->name)) {
dev_err(&pdev->dev, "Memory region busy\n");
ret = -EBUSY;
goto request_mem_failed;
}
i2c->base = ioremap(res->start, res->end - res->start + 1);
if (!i2c->base) {
dev_err(&pdev->dev, "Unable to map registers\n");
ret = -EIO;
goto map_failed;
}
i2c->regstep = pdata->regstep;
ocores_init(i2c, pdata);
init_waitqueue_head(&i2c->wait);
ret = request_irq(res2->start, ocores_isr, 0, pdev->name, i2c);
if (ret) {
dev_err(&pdev->dev, "Cannot claim IRQ\n");
goto request_irq_failed;
}
/* hook up driver to tree */
platform_set_drvdata(pdev, i2c);
i2c->adap = ocores_adapter;
i2c_set_adapdata(&i2c->adap, i2c);
i2c->adap.dev.parent = &pdev->dev;
/* add i2c adapter to i2c tree */
ret = i2c_add_adapter(&i2c->adap);
if (ret) {
dev_err(&pdev->dev, "Failed to add adapter\n");
goto add_adapter_failed;
}
return 0;
add_adapter_failed:
free_irq(res2->start, i2c);
request_irq_failed:
iounmap(i2c->base);
map_failed:
release_mem_region(res->start, res->end - res->start + 1);
request_mem_failed:
kfree(i2c);
return ret;
}
static int __devexit ocores_i2c_remove(struct platform_device* pdev)
{
struct ocores_i2c *i2c = platform_get_drvdata(pdev);
struct resource *res;
/* disable i2c logic */
oc_setreg(i2c, OCI2C_CONTROL, oc_getreg(i2c, OCI2C_CONTROL)
& ~(OCI2C_CTRL_EN|OCI2C_CTRL_IEN));
/* remove adapter & data */
i2c_del_adapter(&i2c->adap);
platform_set_drvdata(pdev, NULL);
res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (res)
free_irq(res->start, i2c);
iounmap(i2c->base);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (res)
release_mem_region(res->start, res->end - res->start + 1);
kfree(i2c);
return 0;
}
static struct platform_driver ocores_i2c_driver = {
.probe = ocores_i2c_probe,
.remove = __devexit_p(ocores_i2c_remove),
.driver = {
.owner = THIS_MODULE,
.name = "ocores-i2c",
},
};
static int __init ocores_i2c_init(void)
{
return platform_driver_register(&ocores_i2c_driver);
}
static void __exit ocores_i2c_exit(void)
{
platform_driver_unregister(&ocores_i2c_driver);
}
module_init(ocores_i2c_init);
module_exit(ocores_i2c_exit);
MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>");
MODULE_DESCRIPTION("OpenCores I2C bus driver");
MODULE_LICENSE("GPL");
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