blob: c302e67ba80c5769f09bbeb3bbbc524b07287dc0 [file] [log] [blame] [edit]
/*
* Copyright (c) 2018 SiFive Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT sifive_spi0
#define LOG_LEVEL CONFIG_SPI_LOG_LEVEL
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(spi_sifive);
#include "spi_sifive.h"
#include <soc.h>
#include <stdbool.h>
/* Helper Functions */
static ALWAYS_INLINE
void sys_set_mask(mem_addr_t addr, uint32_t mask, uint32_t value)
{
uint32_t temp = sys_read32(addr);
temp &= ~(mask);
temp |= value;
sys_write32(temp, addr);
}
static int spi_config(const struct device *dev, uint32_t frequency,
uint16_t operation)
{
uint32_t div;
uint32_t fmt_len;
if (operation & SPI_HALF_DUPLEX) {
return -ENOTSUP;
}
if (SPI_OP_MODE_GET(operation) != SPI_OP_MODE_MASTER) {
return -ENOTSUP;
}
if (operation & SPI_MODE_LOOP) {
return -ENOTSUP;
}
/* Set the SPI frequency */
div = (SPI_CFG(dev)->f_sys / (frequency * 2U)) - 1;
sys_write32((SF_SCKDIV_DIV_MASK & div), SPI_REG(dev, REG_SCKDIV));
/* Set the polarity */
if (operation & SPI_MODE_CPOL) {
/* If CPOL is set, then SCK idles at logical 1 */
sys_set_bit(SPI_REG(dev, REG_SCKMODE), SF_SCKMODE_POL);
} else {
/* SCK idles at logical 0 */
sys_clear_bit(SPI_REG(dev, REG_SCKMODE), SF_SCKMODE_POL);
}
/* Set the phase */
if (operation & SPI_MODE_CPHA) {
/*
* If CPHA is set, then data is sampled
* on the trailing SCK edge
*/
sys_set_bit(SPI_REG(dev, REG_SCKMODE), SF_SCKMODE_PHA);
} else {
/* Data is sampled on the leading SCK edge */
sys_clear_bit(SPI_REG(dev, REG_SCKMODE), SF_SCKMODE_PHA);
}
/* Get the frame length */
fmt_len = SPI_WORD_SIZE_GET(operation);
if (fmt_len > SF_FMT_LEN_MASK) {
return -ENOTSUP;
}
/* Set the frame length */
fmt_len = fmt_len << SF_FMT_LEN;
fmt_len &= SF_FMT_LEN_MASK;
sys_set_mask(SPI_REG(dev, REG_FMT), SF_FMT_LEN_MASK, fmt_len);
if (IS_ENABLED(CONFIG_SPI_EXTENDED_MODES) &&
(operation & SPI_LINES_MASK) != SPI_LINES_SINGLE) {
return -ENOTSUP;
}
/* Set single line operation */
sys_set_mask(SPI_REG(dev, REG_FMT),
SF_FMT_PROTO_MASK,
SF_FMT_PROTO_SINGLE);
/* Set the endianness */
if (operation & SPI_TRANSFER_LSB) {
sys_set_bit(SPI_REG(dev, REG_FMT), SF_FMT_ENDIAN);
} else {
sys_clear_bit(SPI_REG(dev, REG_FMT), SF_FMT_ENDIAN);
}
return 0;
}
static ALWAYS_INLINE bool spi_sifive_send_available(const struct device *dev)
{
return !(sys_read32(SPI_REG(dev, REG_TXDATA)) & SF_TXDATA_FULL);
}
static ALWAYS_INLINE
void spi_sifive_send(const struct device *dev, uint8_t frame)
{
sys_write32((uint32_t) frame, SPI_REG(dev, REG_TXDATA));
}
static ALWAYS_INLINE
bool spi_sifive_recv(const struct device *dev, uint8_t *val)
{
uint32_t reg = sys_read32(SPI_REG(dev, REG_RXDATA));
if (reg & SF_RXDATA_EMPTY) {
return false;
}
*val = (uint8_t) reg;
return true;
}
static void spi_sifive_xfer(const struct device *dev, const bool hw_cs_control)
{
struct spi_context *ctx = &SPI_DATA(dev)->ctx;
uint8_t txd, rxd;
int queued_frames = 0;
while (spi_context_tx_on(ctx) || spi_context_rx_on(ctx) || queued_frames > 0) {
bool send = false;
/* As long as frames remain to be sent, attempt to queue them on Tx FIFO. If
* the FIFO is full then another attempt will be made next pass. If Rx length
* > Tx length then queue dummy Tx in order to read the requested Rx data.
*/
if (spi_context_tx_buf_on(ctx)) {
send = true;
txd = *ctx->tx_buf;
} else if (queued_frames == 0) { /* Implies spi_context_rx_on(). */
send = true;
txd = 0U;
}
if (send && spi_sifive_send_available(dev)) {
spi_sifive_send(dev, txd);
queued_frames++;
spi_context_update_tx(ctx, 1, 1);
}
if (queued_frames > 0 && spi_sifive_recv(dev, &rxd)) {
if (spi_context_rx_buf_on(ctx)) {
*ctx->rx_buf = rxd;
}
queued_frames--;
spi_context_update_rx(ctx, 1, 1);
}
}
/* Deassert the CS line */
if (!hw_cs_control) {
spi_context_cs_control(&SPI_DATA(dev)->ctx, false);
} else {
sys_write32(SF_CSMODE_OFF, SPI_REG(dev, REG_CSMODE));
}
spi_context_complete(ctx, dev, 0);
}
/* API Functions */
static int spi_sifive_init(const struct device *dev)
{
int err;
#ifdef CONFIG_PINCTRL
struct spi_sifive_cfg *cfg = (struct spi_sifive_cfg *)dev->config;
#endif
/* Disable SPI Flash mode */
sys_clear_bit(SPI_REG(dev, REG_FCTRL), SF_FCTRL_EN);
err = spi_context_cs_configure_all(&SPI_DATA(dev)->ctx);
if (err < 0) {
return err;
}
#ifdef CONFIG_PINCTRL
err = pinctrl_apply_state(cfg->pcfg, PINCTRL_STATE_DEFAULT);
if (err < 0) {
return err;
}
#endif
/* Make sure the context is unlocked */
spi_context_unlock_unconditionally(&SPI_DATA(dev)->ctx);
return 0;
}
static int spi_sifive_transceive(const struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs)
{
int rc = 0;
bool hw_cs_control = false;
/* Lock the SPI Context */
spi_context_lock(&SPI_DATA(dev)->ctx, false, NULL, NULL, config);
/* Configure the SPI bus */
SPI_DATA(dev)->ctx.config = config;
/*
* If the chip select configuration is not present, we'll ask the
* SPI peripheral itself to control the CS line
*/
if (!spi_cs_is_gpio(config)) {
hw_cs_control = true;
}
if (!hw_cs_control) {
/*
* If the user has requested manual GPIO control, ask the
* context for control and disable HW control
*/
sys_write32(SF_CSMODE_OFF, SPI_REG(dev, REG_CSMODE));
} else {
/*
* Tell the hardware to control the requested CS pin.
* NOTE:
* For the SPI peripheral, the pin number is not the
* GPIO pin, but the index into the list of available
* CS lines for the SPI peripheral.
*/
sys_write32(config->slave, SPI_REG(dev, REG_CSID));
sys_write32(SF_CSMODE_OFF, SPI_REG(dev, REG_CSMODE));
}
rc = spi_config(dev, config->frequency, config->operation);
if (rc < 0) {
spi_context_release(&SPI_DATA(dev)->ctx, rc);
return rc;
}
spi_context_buffers_setup(&SPI_DATA(dev)->ctx, tx_bufs, rx_bufs, 1);
/* Assert the CS line */
if (!hw_cs_control) {
spi_context_cs_control(&SPI_DATA(dev)->ctx, true);
} else {
sys_write32(SF_CSMODE_HOLD, SPI_REG(dev, REG_CSMODE));
}
/* Perform transfer */
spi_sifive_xfer(dev, hw_cs_control);
rc = spi_context_wait_for_completion(&SPI_DATA(dev)->ctx);
spi_context_release(&SPI_DATA(dev)->ctx, rc);
return rc;
}
static int spi_sifive_release(const struct device *dev,
const struct spi_config *config)
{
spi_context_unlock_unconditionally(&SPI_DATA(dev)->ctx);
return 0;
}
/* Device Instantiation */
static struct spi_driver_api spi_sifive_api = {
.transceive = spi_sifive_transceive,
.release = spi_sifive_release,
};
#define SPI_INIT(n) \
PINCTRL_DT_INST_DEFINE(n); \
static struct spi_sifive_data spi_sifive_data_##n = { \
SPI_CONTEXT_INIT_LOCK(spi_sifive_data_##n, ctx), \
SPI_CONTEXT_INIT_SYNC(spi_sifive_data_##n, ctx), \
SPI_CONTEXT_CS_GPIOS_INITIALIZE(DT_DRV_INST(n), ctx) \
}; \
static struct spi_sifive_cfg spi_sifive_cfg_##n = { \
.base = DT_INST_REG_ADDR_BY_NAME(n, control), \
.f_sys = SIFIVE_PERIPHERAL_CLOCK_FREQUENCY, \
.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(n), \
}; \
DEVICE_DT_INST_DEFINE(n, \
spi_sifive_init, \
NULL, \
&spi_sifive_data_##n, \
&spi_sifive_cfg_##n, \
POST_KERNEL, \
CONFIG_SPI_INIT_PRIORITY, \
&spi_sifive_api);
DT_INST_FOREACH_STATUS_OKAY(SPI_INIT)