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u-boot/drivers/spi/omap3_spi.c
Nikita Kiryanov 5753d09b10 spi: omap3: add support for more word lengths 
Current implementation only supports 8 bit word lengths, even though
omap3 can handle anything between 4 and 32.

Update the spi interface to support changing the SPI word length,
and implement it in omap3_spi driver to support the full range of
possible word lengths.
This implementation is backwards compatible by defaulting to the old
behavior of 8 bit word lengths.
Also, it required a change to the omap3_spi non static I/O functions,
but since they are not used anywhere else, no collateral changes are required.

Cc: Tom Rini <trini@ti.com>
Cc: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
Cc: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
2013-11-12 10:02:44 +01:00

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/*
* 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));
/* 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)
{
}
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