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/*
* linux/arch/mips/tx4938/toshiba_rbtx4938/spi_txx9.c
* Copyright (C) 2000-2001 Toshiba Corporation
*
* 2003-2005 (c) MontaVista Software, Inc. 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.
*
* Support for TX4938 in 2.6 - Manish Lachwani (mlachwani@mvista.com)
*/
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <asm/tx4938/spi.h>
#include <asm/tx4938/tx4938.h>
static int (*txx9_spi_cs_func)(int chipid, int on);
static DEFINE_SPINLOCK(txx9_spi_lock);
extern unsigned int txx9_gbus_clock;
#define SPI_FIFO_SIZE 4
void __init txx9_spi_init(unsigned long base, int (*cs_func)(int chipid, int on))
{
txx9_spi_cs_func = cs_func;
/* enter config mode */
tx4938_spiptr->mcr = TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR;
}
static DECLARE_WAIT_QUEUE_HEAD(txx9_spi_wait);
static irqreturn_t txx9_spi_interrupt(int irq, void *dev_id)
{
/* disable rx intr */
tx4938_spiptr->cr0 &= ~TXx9_SPCR0_RBSIE;
wake_up(&txx9_spi_wait);
return IRQ_HANDLED;
}
static struct irqaction txx9_spi_action = {
.handler = txx9_spi_interrupt,
.name = "spi",
};
void __init txx9_spi_irqinit(int irc_irq)
{
setup_irq(irc_irq, &txx9_spi_action);
}
int txx9_spi_io(int chipid, struct spi_dev_desc *desc,
unsigned char **inbufs, unsigned int *incounts,
unsigned char **outbufs, unsigned int *outcounts,
int cansleep)
{
unsigned int incount, outcount;
unsigned char *inp, *outp;
int ret;
unsigned long flags;
spin_lock_irqsave(&txx9_spi_lock, flags);
if ((tx4938_spiptr->mcr & TXx9_SPMCR_OPMODE) == TXx9_SPMCR_ACTIVE) {
spin_unlock_irqrestore(&txx9_spi_lock, flags);
return -EBUSY;
}
/* enter config mode */
tx4938_spiptr->mcr = TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR;
tx4938_spiptr->cr0 =
(desc->byteorder ? TXx9_SPCR0_SBOS : 0) |
(desc->polarity ? TXx9_SPCR0_SPOL : 0) |
(desc->phase ? TXx9_SPCR0_SPHA : 0) |
0x08;
tx4938_spiptr->cr1 =
(((TXX9_IMCLK + desc->baud) / (2 * desc->baud) - 1) << 8) |
0x08 /* 8 bit only */;
/* enter active mode */
tx4938_spiptr->mcr = TXx9_SPMCR_ACTIVE;
spin_unlock_irqrestore(&txx9_spi_lock, flags);
/* CS ON */
if ((ret = txx9_spi_cs_func(chipid, 1)) < 0) {
spin_unlock_irqrestore(&txx9_spi_lock, flags);
return ret;
}
udelay(desc->tcss);
/* do scatter IO */
inp = inbufs ? *inbufs : NULL;
outp = outbufs ? *outbufs : NULL;
incount = 0;
outcount = 0;
while (1) {
unsigned char data;
unsigned int count;
int i;
if (!incount) {
incount = incounts ? *incounts++ : 0;
inp = (incount && inbufs) ? *inbufs++ : NULL;
}
if (!outcount) {
outcount = outcounts ? *outcounts++ : 0;
outp = (outcount && outbufs) ? *outbufs++ : NULL;
}
if (!inp && !outp)
break;
count = SPI_FIFO_SIZE;
if (incount)
count = min(count, incount);
if (outcount)
count = min(count, outcount);
/* now tx must be idle... */
while (!(tx4938_spiptr->sr & TXx9_SPSR_SIDLE))
;
tx4938_spiptr->cr0 =
(tx4938_spiptr->cr0 & ~TXx9_SPCR0_RXIFL_MASK) |
((count - 1) << 12);
if (cansleep) {
/* enable rx intr */
tx4938_spiptr->cr0 |= TXx9_SPCR0_RBSIE;
}
/* send */
for (i = 0; i < count; i++)
tx4938_spiptr->dr = inp ? *inp++ : 0;
/* wait all rx data */
if (cansleep) {
wait_event(txx9_spi_wait,
tx4938_spiptr->sr & TXx9_SPSR_SRRDY);
} else {
while (!(tx4938_spiptr->sr & TXx9_SPSR_RBSI))
;
}
/* receive */
for (i = 0; i < count; i++) {
data = tx4938_spiptr->dr;
if (outp)
*outp++ = data;
}
if (incount)
incount -= count;
if (outcount)
outcount -= count;
}
/* CS OFF */
udelay(desc->tcsh);
txx9_spi_cs_func(chipid, 0);
udelay(desc->tcsr);
spin_lock_irqsave(&txx9_spi_lock, flags);
/* enter config mode */
tx4938_spiptr->mcr = TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR;
spin_unlock_irqrestore(&txx9_spi_lock, flags);
return 0;
}
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