u-boot/drivers/spi/fsl_espi.c
Hou Zhiqiang afb907061a powerpc/espi: remove 80us delay to improve transfer performance
Replace 80 mircoseconds delay with polling flag ESPI_EV_TXE.

Signed-off-by: Hou Zhiqiang <B48286@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
2014-06-05 12:56:20 -07:00

389 lines
9.4 KiB
C

/*
* eSPI controller driver.
*
* Copyright 2010-2011 Freescale Semiconductor, Inc.
* Author: Mingkai Hu (Mingkai.hu@freescale.com)
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <malloc.h>
#include <spi.h>
#include <asm/immap_85xx.h>
struct fsl_spi_slave {
struct spi_slave slave;
ccsr_espi_t *espi;
unsigned int div16;
unsigned int pm;
int tx_timeout;
unsigned int mode;
size_t cmd_len;
u8 cmd_buf[16];
size_t data_len;
unsigned int max_transfer_length;
};
#define to_fsl_spi_slave(s) container_of(s, struct fsl_spi_slave, slave)
#define US_PER_SECOND 1000000UL
#define ESPI_MAX_CS_NUM 4
#define ESPI_FIFO_WIDTH_BIT 32
#define ESPI_EV_RNE (1 << 9)
#define ESPI_EV_TNF (1 << 8)
#define ESPI_EV_DON (1 << 14)
#define ESPI_EV_TXE (1 << 15)
#define ESPI_EV_RFCNT_SHIFT 24
#define ESPI_EV_RFCNT_MASK (0x3f << ESPI_EV_RFCNT_SHIFT)
#define ESPI_MODE_EN (1 << 31) /* Enable interface */
#define ESPI_MODE_TXTHR(x) ((x) << 8) /* Tx FIFO threshold */
#define ESPI_MODE_RXTHR(x) ((x) << 0) /* Rx FIFO threshold */
#define ESPI_COM_CS(x) ((x) << 30)
#define ESPI_COM_TRANLEN(x) ((x) << 0)
#define ESPI_CSMODE_CI_INACTIVEHIGH (1 << 31)
#define ESPI_CSMODE_CP_BEGIN_EDGCLK (1 << 30)
#define ESPI_CSMODE_REV_MSB_FIRST (1 << 29)
#define ESPI_CSMODE_DIV16 (1 << 28)
#define ESPI_CSMODE_PM(x) ((x) << 24)
#define ESPI_CSMODE_POL_ASSERTED_LOW (1 << 20)
#define ESPI_CSMODE_LEN(x) ((x) << 16)
#define ESPI_CSMODE_CSBEF(x) ((x) << 12)
#define ESPI_CSMODE_CSAFT(x) ((x) << 8)
#define ESPI_CSMODE_CSCG(x) ((x) << 3)
#define ESPI_CSMODE_INIT_VAL (ESPI_CSMODE_POL_ASSERTED_LOW | \
ESPI_CSMODE_CSBEF(0) | ESPI_CSMODE_CSAFT(0) | \
ESPI_CSMODE_CSCG(1))
#define ESPI_MAX_DATA_TRANSFER_LEN 0xFFF0
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct fsl_spi_slave *fsl;
sys_info_t sysinfo;
unsigned long spibrg = 0;
unsigned long spi_freq = 0;
unsigned char pm = 0;
if (!spi_cs_is_valid(bus, cs))
return NULL;
fsl = spi_alloc_slave(struct fsl_spi_slave, bus, cs);
if (!fsl)
return NULL;
fsl->espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
fsl->mode = mode;
fsl->max_transfer_length = ESPI_MAX_DATA_TRANSFER_LEN;
/* Set eSPI BRG clock source */
get_sys_info(&sysinfo);
spibrg = sysinfo.freq_systembus / 2;
fsl->div16 = 0;
if ((spibrg / max_hz) > 32) {
fsl->div16 = ESPI_CSMODE_DIV16;
pm = spibrg / (max_hz * 16 * 2);
if (pm > 16) {
pm = 16;
debug("Requested speed is too low: %d Hz, %ld Hz "
"is used.\n", max_hz, spibrg / (32 * 16));
}
} else
pm = spibrg / (max_hz * 2);
if (pm)
pm--;
fsl->pm = pm;
if (fsl->div16)
spi_freq = spibrg / ((pm + 1) * 2 * 16);
else
spi_freq = spibrg / ((pm + 1) * 2);
/* set tx_timeout to 10 times of one espi FIFO entry go out */
fsl->tx_timeout = DIV_ROUND_UP((US_PER_SECOND * ESPI_FIFO_WIDTH_BIT
* 10), spi_freq);
return &fsl->slave;
}
void spi_free_slave(struct spi_slave *slave)
{
struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
free(fsl);
}
void spi_init(void)
{
}
int spi_claim_bus(struct spi_slave *slave)
{
struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
ccsr_espi_t *espi = fsl->espi;
unsigned char pm = fsl->pm;
unsigned int cs = slave->cs;
unsigned int mode = fsl->mode;
unsigned int div16 = fsl->div16;
int i;
debug("%s: bus:%i cs:%i\n", __func__, slave->bus, cs);
/* Enable eSPI interface */
out_be32(&espi->mode, ESPI_MODE_RXTHR(3)
| ESPI_MODE_TXTHR(4) | ESPI_MODE_EN);
out_be32(&espi->event, 0xffffffff); /* Clear all eSPI events */
out_be32(&espi->mask, 0x00000000); /* Mask all eSPI interrupts */
/* Init CS mode interface */
for (i = 0; i < ESPI_MAX_CS_NUM; i++)
out_be32(&espi->csmode[i], ESPI_CSMODE_INIT_VAL);
out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs]) &
~(ESPI_CSMODE_PM(0xF) | ESPI_CSMODE_DIV16
| ESPI_CSMODE_CI_INACTIVEHIGH | ESPI_CSMODE_CP_BEGIN_EDGCLK
| ESPI_CSMODE_REV_MSB_FIRST | ESPI_CSMODE_LEN(0xF)));
/* Set eSPI BRG clock source */
out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
| ESPI_CSMODE_PM(pm) | div16);
/* Set eSPI mode */
if (mode & SPI_CPHA)
out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
| ESPI_CSMODE_CP_BEGIN_EDGCLK);
if (mode & SPI_CPOL)
out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
| ESPI_CSMODE_CI_INACTIVEHIGH);
/* Character bit order: msb first */
out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
| ESPI_CSMODE_REV_MSB_FIRST);
/* Character length in bits, between 0x3~0xf, i.e. 4bits~16bits */
out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
| ESPI_CSMODE_LEN(7));
return 0;
}
void spi_release_bus(struct spi_slave *slave)
{
}
static void fsl_espi_tx(struct fsl_spi_slave *fsl, const void *dout)
{
ccsr_espi_t *espi = fsl->espi;
unsigned int tmpdout, event;
int tmp_tx_timeout;
if (dout)
tmpdout = *(u32 *)dout;
else
tmpdout = 0;
out_be32(&espi->tx, tmpdout);
out_be32(&espi->event, ESPI_EV_TNF);
debug("***spi_xfer:...%08x written\n", tmpdout);
tmp_tx_timeout = fsl->tx_timeout;
/* Wait for eSPI transmit to go out */
while (tmp_tx_timeout--) {
event = in_be32(&espi->event);
if (event & ESPI_EV_DON || event & ESPI_EV_TXE) {
out_be32(&espi->event, ESPI_EV_TXE);
break;
}
udelay(1);
}
if (tmp_tx_timeout < 0)
debug("***spi_xfer:...Tx timeout! event = %08x\n", event);
}
static int fsl_espi_rx(struct fsl_spi_slave *fsl, void *din, unsigned int bytes)
{
ccsr_espi_t *espi = fsl->espi;
unsigned int tmpdin, rx_times;
unsigned char *buf, *p_cursor;
if (bytes <= 0)
return 0;
rx_times = DIV_ROUND_UP(bytes, 4);
buf = (unsigned char *)malloc(4 * rx_times);
if (!buf) {
debug("SF: Failed to malloc memory.\n");
return -1;
}
p_cursor = buf;
while (rx_times--) {
tmpdin = in_be32(&espi->rx);
debug("***spi_xfer:...%08x readed\n", tmpdin);
*(u32 *)p_cursor = tmpdin;
p_cursor += 4;
}
if (din)
memcpy(din, buf, bytes);
free(buf);
out_be32(&espi->event, ESPI_EV_RNE);
return bytes;
}
int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out,
void *data_in, unsigned long flags)
{
struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
ccsr_espi_t *espi = fsl->espi;
unsigned int event, rx_bytes;
const void *dout = NULL;
void *din = NULL;
int len = 0;
int num_blks, num_chunks, max_tran_len, tran_len;
int num_bytes;
unsigned char *buffer = NULL;
size_t buf_len;
u8 *cmd_buf = fsl->cmd_buf;
size_t cmd_len = fsl->cmd_len;
size_t data_len = bitlen / 8;
size_t rx_offset = 0;
int rf_cnt;
max_tran_len = fsl->max_transfer_length;
switch (flags) {
case SPI_XFER_BEGIN:
cmd_len = fsl->cmd_len = data_len;
memcpy(cmd_buf, data_out, cmd_len);
return 0;
case 0:
case SPI_XFER_END:
if (bitlen == 0) {
spi_cs_deactivate(slave);
return 0;
}
buf_len = 2 * cmd_len + min(data_len, max_tran_len);
len = cmd_len + data_len;
rx_offset = cmd_len;
buffer = (unsigned char *)malloc(buf_len);
if (!buffer) {
debug("SF: Failed to malloc memory.\n");
return 1;
}
memcpy(buffer, cmd_buf, cmd_len);
if (data_in == NULL)
memcpy(buffer + cmd_len, data_out, data_len);
break;
case SPI_XFER_BEGIN | SPI_XFER_END:
len = data_len;
buffer = (unsigned char *)malloc(len * 2);
if (!buffer) {
debug("SF: Failed to malloc memory.\n");
return 1;
}
memcpy(buffer, data_out, len);
rx_offset = len;
cmd_len = 0;
break;
}
debug("spi_xfer: data_out %08X(%p) data_in %08X(%p) len %u\n",
*(uint *)data_out, data_out, *(uint *)data_in, data_in, len);
num_chunks = DIV_ROUND_UP(data_len, max_tran_len);
while (num_chunks--) {
if (data_in)
din = buffer + rx_offset;
dout = buffer;
tran_len = min(data_len , max_tran_len);
num_blks = DIV_ROUND_UP(tran_len + cmd_len, 4);
num_bytes = (tran_len + cmd_len) % 4;
fsl->data_len = tran_len + cmd_len;
spi_cs_activate(slave);
/* Clear all eSPI events */
out_be32(&espi->event , 0xffffffff);
/* handle data in 32-bit chunks */
while (num_blks) {
event = in_be32(&espi->event);
if (event & ESPI_EV_TNF) {
fsl_espi_tx(fsl, dout);
/* Set up the next iteration */
if (len > 4) {
len -= 4;
dout += 4;
}
}
event = in_be32(&espi->event);
if (event & ESPI_EV_RNE) {
rf_cnt = ((event & ESPI_EV_RFCNT_MASK)
>> ESPI_EV_RFCNT_SHIFT);
if (rf_cnt >= 4)
rx_bytes = 4;
else if (num_blks == 1 && rf_cnt == num_bytes)
rx_bytes = num_bytes;
else
continue;
if (fsl_espi_rx(fsl, din, rx_bytes)
== rx_bytes) {
num_blks--;
if (din)
din = (unsigned char *)din
+ rx_bytes;
}
}
}
if (data_in) {
memcpy(data_in, buffer + 2 * cmd_len, tran_len);
if (*buffer == 0x0b) {
data_in += tran_len;
data_len -= tran_len;
*(int *)buffer += tran_len;
}
}
spi_cs_deactivate(slave);
}
free(buffer);
return 0;
}
int spi_cs_is_valid(unsigned int bus, unsigned int cs)
{
return bus == 0 && cs < ESPI_MAX_CS_NUM;
}
void spi_cs_activate(struct spi_slave *slave)
{
struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
ccsr_espi_t *espi = fsl->espi;
unsigned int com = 0;
size_t data_len = fsl->data_len;
com &= ~(ESPI_COM_CS(0x3) | ESPI_COM_TRANLEN(0xFFFF));
com |= ESPI_COM_CS(slave->cs);
com |= ESPI_COM_TRANLEN(data_len - 1);
out_be32(&espi->com, com);
}
void spi_cs_deactivate(struct spi_slave *slave)
{
struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
ccsr_espi_t *espi = fsl->espi;
/* clear the RXCNT and TXCNT */
out_be32(&espi->mode, in_be32(&espi->mode) & (~ESPI_MODE_EN));
out_be32(&espi->mode, in_be32(&espi->mode) | ESPI_MODE_EN);
}