u-boot/drivers/spi/omap3_spi.c
Vasili Galka ce6889a997 drivers/spi/omap3: Bug fix of premature write transfer completion
The logic determining SPI "write" transfer completion was faulty. At
certain conditions (e.g. slow SPI clock freq) the transfers were
interrupted before completion. Both EOT and TXS flags of channel
status registeer shall be checked to ensure that all data was
transferred. Tested on AM3359 chip.

Signed-off-by: Vasili Galka <vasili@visionmap.com>
2014-03-12 16:22:12 -04:00

453 lines
12 KiB
C

/*
* Copyright (C) 2010 Dirk Behme <dirk.behme@googlemail.com>
*
* Driver for McSPI controller on OMAP3. Based on davinci_spi.c
* Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
*
* Copyright (C) 2007 Atmel Corporation
*
* Parts taken from linux/drivers/spi/omap2_mcspi.c
* Copyright (C) 2005, 2006 Nokia Corporation
*
* Modified by Ruslan Araslanov <ruslan.araslanov@vitecmm.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <spi.h>
#include <malloc.h>
#include <asm/io.h>
#include "omap3_spi.h"
#define SPI_WAIT_TIMEOUT 3000000
static void spi_reset(struct omap3_spi_slave *ds)
{
unsigned int tmp;
writel(OMAP3_MCSPI_SYSCONFIG_SOFTRESET, &ds->regs->sysconfig);
do {
tmp = readl(&ds->regs->sysstatus);
} while (!(tmp & OMAP3_MCSPI_SYSSTATUS_RESETDONE));
writel(OMAP3_MCSPI_SYSCONFIG_AUTOIDLE |
OMAP3_MCSPI_SYSCONFIG_ENAWAKEUP |
OMAP3_MCSPI_SYSCONFIG_SMARTIDLE,
&ds->regs->sysconfig);
writel(OMAP3_MCSPI_WAKEUPENABLE_WKEN, &ds->regs->wakeupenable);
}
static void omap3_spi_write_chconf(struct omap3_spi_slave *ds, int val)
{
writel(val, &ds->regs->channel[ds->slave.cs].chconf);
/* Flash post writes to make immediate effect */
readl(&ds->regs->channel[ds->slave.cs].chconf);
}
static void omap3_spi_set_enable(struct omap3_spi_slave *ds, int enable)
{
writel(enable, &ds->regs->channel[ds->slave.cs].chctrl);
/* Flash post writes to make immediate effect */
readl(&ds->regs->channel[ds->slave.cs].chctrl);
}
void spi_init()
{
/* do nothing */
}
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct omap3_spi_slave *ds;
struct mcspi *regs;
/*
* OMAP3 McSPI (MultiChannel SPI) has 4 busses (modules)
* with different number of chip selects (CS, channels):
* McSPI1 has 4 CS (bus 0, cs 0 - 3)
* McSPI2 has 2 CS (bus 1, cs 0 - 1)
* McSPI3 has 2 CS (bus 2, cs 0 - 1)
* McSPI4 has 1 CS (bus 3, cs 0)
*/
switch (bus) {
case 0:
regs = (struct mcspi *)OMAP3_MCSPI1_BASE;
break;
#ifdef OMAP3_MCSPI2_BASE
case 1:
regs = (struct mcspi *)OMAP3_MCSPI2_BASE;
break;
#endif
#ifdef OMAP3_MCSPI3_BASE
case 2:
regs = (struct mcspi *)OMAP3_MCSPI3_BASE;
break;
#endif
#ifdef OMAP3_MCSPI4_BASE
case 3:
regs = (struct mcspi *)OMAP3_MCSPI4_BASE;
break;
#endif
default:
printf("SPI error: unsupported bus %i. \
Supported busses 0 - 3\n", bus);
return NULL;
}
if (((bus == 0) && (cs > 3)) ||
((bus == 1) && (cs > 1)) ||
((bus == 2) && (cs > 1)) ||
((bus == 3) && (cs > 0))) {
printf("SPI error: unsupported chip select %i \
on bus %i\n", cs, bus);
return NULL;
}
if (max_hz > OMAP3_MCSPI_MAX_FREQ) {
printf("SPI error: unsupported frequency %i Hz. \
Max frequency is 48 Mhz\n", max_hz);
return NULL;
}
if (mode > SPI_MODE_3) {
printf("SPI error: unsupported SPI mode %i\n", mode);
return NULL;
}
ds = spi_alloc_slave(struct omap3_spi_slave, bus, cs);
if (!ds) {
printf("SPI error: malloc of SPI structure failed\n");
return NULL;
}
ds->regs = regs;
ds->freq = max_hz;
ds->mode = mode;
return &ds->slave;
}
void spi_free_slave(struct spi_slave *slave)
{
struct omap3_spi_slave *ds = to_omap3_spi(slave);
free(ds);
}
int spi_claim_bus(struct spi_slave *slave)
{
struct omap3_spi_slave *ds = to_omap3_spi(slave);
unsigned int conf, div = 0;
/* McSPI global module configuration */
/*
* setup when switching from (reset default) slave mode
* to single-channel master mode
*/
spi_reset(ds);
conf = readl(&ds->regs->modulctrl);
conf &= ~(OMAP3_MCSPI_MODULCTRL_STEST | OMAP3_MCSPI_MODULCTRL_MS);
conf |= OMAP3_MCSPI_MODULCTRL_SINGLE;
writel(conf, &ds->regs->modulctrl);
/* McSPI individual channel configuration */
/* Calculate clock divisor. Valid range: 0x0 - 0xC ( /1 - /4096 ) */
if (ds->freq) {
while (div <= 0xC && (OMAP3_MCSPI_MAX_FREQ / (1 << div))
> ds->freq)
div++;
} else
div = 0xC;
conf = readl(&ds->regs->channel[ds->slave.cs].chconf);
/* standard 4-wire master mode: SCK, MOSI/out, MISO/in, nCS
* REVISIT: this controller could support SPI_3WIRE mode.
*/
#ifdef CONFIG_OMAP3_SPI_D0_D1_SWAPPED
/*
* Some boards have D0 wired as MOSI / D1 as MISO instead of
* The normal D0 as MISO / D1 as MOSI.
*/
conf &= ~OMAP3_MCSPI_CHCONF_DPE0;
conf |= OMAP3_MCSPI_CHCONF_IS|OMAP3_MCSPI_CHCONF_DPE1;
#else
conf &= ~(OMAP3_MCSPI_CHCONF_IS|OMAP3_MCSPI_CHCONF_DPE1);
conf |= OMAP3_MCSPI_CHCONF_DPE0;
#endif
/* wordlength */
conf &= ~OMAP3_MCSPI_CHCONF_WL_MASK;
conf |= (ds->slave.wordlen - 1) << 7;
/* set chipselect polarity; manage with FORCE */
if (!(ds->mode & SPI_CS_HIGH))
conf |= OMAP3_MCSPI_CHCONF_EPOL; /* active-low; normal */
else
conf &= ~OMAP3_MCSPI_CHCONF_EPOL;
/* set clock divisor */
conf &= ~OMAP3_MCSPI_CHCONF_CLKD_MASK;
conf |= div << 2;
/* set SPI mode 0..3 */
if (ds->mode & SPI_CPOL)
conf |= OMAP3_MCSPI_CHCONF_POL;
else
conf &= ~OMAP3_MCSPI_CHCONF_POL;
if (ds->mode & SPI_CPHA)
conf |= OMAP3_MCSPI_CHCONF_PHA;
else
conf &= ~OMAP3_MCSPI_CHCONF_PHA;
/* Transmit & receive mode */
conf &= ~OMAP3_MCSPI_CHCONF_TRM_MASK;
omap3_spi_write_chconf(ds,conf);
return 0;
}
void spi_release_bus(struct spi_slave *slave)
{
struct omap3_spi_slave *ds = to_omap3_spi(slave);
/* Reset the SPI hardware */
spi_reset(ds);
}
int omap3_spi_write(struct spi_slave *slave, unsigned int len, const void *txp,
unsigned long flags)
{
struct omap3_spi_slave *ds = to_omap3_spi(slave);
int i;
int timeout = SPI_WAIT_TIMEOUT;
int chconf = readl(&ds->regs->channel[ds->slave.cs].chconf);
/* Enable the channel */
omap3_spi_set_enable(ds,OMAP3_MCSPI_CHCTRL_EN);
chconf &= ~(OMAP3_MCSPI_CHCONF_TRM_MASK | OMAP3_MCSPI_CHCONF_WL_MASK);
chconf |= (ds->slave.wordlen - 1) << 7;
chconf |= OMAP3_MCSPI_CHCONF_TRM_TX_ONLY;
chconf |= OMAP3_MCSPI_CHCONF_FORCE;
omap3_spi_write_chconf(ds,chconf);
for (i = 0; i < len; i++) {
/* wait till TX register is empty (TXS == 1) */
while (!(readl(&ds->regs->channel[ds->slave.cs].chstat) &
OMAP3_MCSPI_CHSTAT_TXS)) {
if (--timeout <= 0) {
printf("SPI TXS timed out, status=0x%08x\n",
readl(&ds->regs->channel[ds->slave.cs].chstat));
return -1;
}
}
/* Write the data */
unsigned int *tx = &ds->regs->channel[ds->slave.cs].tx;
if (ds->slave.wordlen > 16)
writel(((u32 *)txp)[i], tx);
else if (ds->slave.wordlen > 8)
writel(((u16 *)txp)[i], tx);
else
writel(((u8 *)txp)[i], tx);
}
/* wait to finish of transfer */
while ((readl(&ds->regs->channel[ds->slave.cs].chstat) &
(OMAP3_MCSPI_CHSTAT_EOT | OMAP3_MCSPI_CHSTAT_TXS)) !=
(OMAP3_MCSPI_CHSTAT_EOT | OMAP3_MCSPI_CHSTAT_TXS));
/* Disable the channel otherwise the next immediate RX will get affected */
omap3_spi_set_enable(ds,OMAP3_MCSPI_CHCTRL_DIS);
if (flags & SPI_XFER_END) {
chconf &= ~OMAP3_MCSPI_CHCONF_FORCE;
omap3_spi_write_chconf(ds,chconf);
}
return 0;
}
int omap3_spi_read(struct spi_slave *slave, unsigned int len, void *rxp,
unsigned long flags)
{
struct omap3_spi_slave *ds = to_omap3_spi(slave);
int i;
int timeout = SPI_WAIT_TIMEOUT;
int chconf = readl(&ds->regs->channel[ds->slave.cs].chconf);
/* Enable the channel */
omap3_spi_set_enable(ds,OMAP3_MCSPI_CHCTRL_EN);
chconf &= ~(OMAP3_MCSPI_CHCONF_TRM_MASK | OMAP3_MCSPI_CHCONF_WL_MASK);
chconf |= (ds->slave.wordlen - 1) << 7;
chconf |= OMAP3_MCSPI_CHCONF_TRM_RX_ONLY;
chconf |= OMAP3_MCSPI_CHCONF_FORCE;
omap3_spi_write_chconf(ds,chconf);
writel(0, &ds->regs->channel[ds->slave.cs].tx);
for (i = 0; i < len; i++) {
/* Wait till RX register contains data (RXS == 1) */
while (!(readl(&ds->regs->channel[ds->slave.cs].chstat) &
OMAP3_MCSPI_CHSTAT_RXS)) {
if (--timeout <= 0) {
printf("SPI RXS timed out, status=0x%08x\n",
readl(&ds->regs->channel[ds->slave.cs].chstat));
return -1;
}
}
/* Disable the channel to prevent furher receiving */
if(i == (len - 1))
omap3_spi_set_enable(ds,OMAP3_MCSPI_CHCTRL_DIS);
/* Read the data */
unsigned int *rx = &ds->regs->channel[ds->slave.cs].rx;
if (ds->slave.wordlen > 16)
((u32 *)rxp)[i] = readl(rx);
else if (ds->slave.wordlen > 8)
((u16 *)rxp)[i] = (u16)readl(rx);
else
((u8 *)rxp)[i] = (u8)readl(rx);
}
if (flags & SPI_XFER_END) {
chconf &= ~OMAP3_MCSPI_CHCONF_FORCE;
omap3_spi_write_chconf(ds,chconf);
}
return 0;
}
/*McSPI Transmit Receive Mode*/
int omap3_spi_txrx(struct spi_slave *slave, unsigned int len,
const void *txp, void *rxp, unsigned long flags)
{
struct omap3_spi_slave *ds = to_omap3_spi(slave);
int timeout = SPI_WAIT_TIMEOUT;
int chconf = readl(&ds->regs->channel[ds->slave.cs].chconf);
int irqstatus = readl(&ds->regs->irqstatus);
int i=0;
/*Enable SPI channel*/
omap3_spi_set_enable(ds,OMAP3_MCSPI_CHCTRL_EN);
/*set TRANSMIT-RECEIVE Mode*/
chconf &= ~(OMAP3_MCSPI_CHCONF_TRM_MASK | OMAP3_MCSPI_CHCONF_WL_MASK);
chconf |= (ds->slave.wordlen - 1) << 7;
chconf |= OMAP3_MCSPI_CHCONF_FORCE;
omap3_spi_write_chconf(ds,chconf);
/*Shift in and out 1 byte at time*/
for (i=0; i < len; i++){
/* Write: wait for TX empty (TXS == 1)*/
irqstatus |= (1<< (4*(ds->slave.bus)));
while (!(readl(&ds->regs->channel[ds->slave.cs].chstat) &
OMAP3_MCSPI_CHSTAT_TXS)) {
if (--timeout <= 0) {
printf("SPI TXS timed out, status=0x%08x\n",
readl(&ds->regs->channel[ds->slave.cs].chstat));
return -1;
}
}
/* Write the data */
unsigned int *tx = &ds->regs->channel[ds->slave.cs].tx;
if (ds->slave.wordlen > 16)
writel(((u32 *)txp)[i], tx);
else if (ds->slave.wordlen > 8)
writel(((u16 *)txp)[i], tx);
else
writel(((u8 *)txp)[i], tx);
/*Read: wait for RX containing data (RXS == 1)*/
while (!(readl(&ds->regs->channel[ds->slave.cs].chstat) &
OMAP3_MCSPI_CHSTAT_RXS)) {
if (--timeout <= 0) {
printf("SPI RXS timed out, status=0x%08x\n",
readl(&ds->regs->channel[ds->slave.cs].chstat));
return -1;
}
}
/* Read the data */
unsigned int *rx = &ds->regs->channel[ds->slave.cs].rx;
if (ds->slave.wordlen > 16)
((u32 *)rxp)[i] = readl(rx);
else if (ds->slave.wordlen > 8)
((u16 *)rxp)[i] = (u16)readl(rx);
else
((u8 *)rxp)[i] = (u8)readl(rx);
}
/* Disable the channel */
omap3_spi_set_enable(ds,OMAP3_MCSPI_CHCTRL_DIS);
/*if transfer must be terminated disable the channel*/
if (flags & SPI_XFER_END) {
chconf &= ~OMAP3_MCSPI_CHCONF_FORCE;
omap3_spi_write_chconf(ds,chconf);
}
return 0;
}
int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct omap3_spi_slave *ds = to_omap3_spi(slave);
unsigned int len;
int ret = -1;
if (ds->slave.wordlen < 4 || ds->slave.wordlen > 32) {
printf("omap3_spi: invalid wordlen %d\n", ds->slave.wordlen);
return -1;
}
if (bitlen % ds->slave.wordlen)
return -1;
len = bitlen / ds->slave.wordlen;
if (bitlen == 0) { /* only change CS */
int chconf = readl(&ds->regs->channel[ds->slave.cs].chconf);
if (flags & SPI_XFER_BEGIN) {
omap3_spi_set_enable(ds,OMAP3_MCSPI_CHCTRL_EN);
chconf |= OMAP3_MCSPI_CHCONF_FORCE;
omap3_spi_write_chconf(ds,chconf);
}
if (flags & SPI_XFER_END) {
chconf &= ~OMAP3_MCSPI_CHCONF_FORCE;
omap3_spi_write_chconf(ds,chconf);
omap3_spi_set_enable(ds,OMAP3_MCSPI_CHCTRL_DIS);
}
ret = 0;
} else {
if (dout != NULL && din != NULL)
ret = omap3_spi_txrx(slave, len, dout, din, flags);
else if (dout != NULL)
ret = omap3_spi_write(slave, len, dout, flags);
else if (din != NULL)
ret = omap3_spi_read(slave, len, din, flags);
}
return ret;
}
int spi_cs_is_valid(unsigned int bus, unsigned int cs)
{
return 1;
}
void spi_cs_activate(struct spi_slave *slave)
{
}
void spi_cs_deactivate(struct spi_slave *slave)
{
}