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zephyr/drivers/spi/spi_nrfx_spi.c
Andrzej Głąbek db4344b659 drivers: spi: nrfx: Deactivate CS from thread context 
... so that it is possible to use a GPIO expander pin as the CS line.
Communication with the expander may involve an operation that cannot
be done from the interrupt context (e.g. an I2C transaction).

Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>
2024-01-09 12:06:35 +01:00

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12 KiB
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/*
* Copyright (c) 2017 - 2018, Nordic Semiconductor ASA
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/drivers/spi.h>
#include <zephyr/pm/device.h>
#include <zephyr/drivers/pinctrl.h>
#include <soc.h>
#include <nrfx_spi.h>
#include <zephyr/logging/log.h>
#include <zephyr/irq.h>
LOG_MODULE_REGISTER(spi_nrfx_spi, CONFIG_SPI_LOG_LEVEL);
#include "spi_context.h"
#include "spi_nrfx_common.h"
struct spi_nrfx_data {
struct spi_context ctx;
const struct device *dev;
size_t chunk_len;
bool busy;
bool initialized;
};
struct spi_nrfx_config {
nrfx_spi_t spi;
nrfx_spi_config_t def_config;
void (*irq_connect)(void);
const struct pinctrl_dev_config *pcfg;
uint32_t wake_pin;
nrfx_gpiote_t wake_gpiote;
};
static void event_handler(const nrfx_spi_evt_t *p_event, void *p_context);
static inline nrf_spi_frequency_t get_nrf_spi_frequency(uint32_t frequency)
{
/* Get the highest supported frequency not exceeding the requested one.
*/
if (frequency < 250000) {
return NRF_SPI_FREQ_125K;
} else if (frequency < 500000) {
return NRF_SPI_FREQ_250K;
} else if (frequency < 1000000) {
return NRF_SPI_FREQ_500K;
} else if (frequency < 2000000) {
return NRF_SPI_FREQ_1M;
} else if (frequency < 4000000) {
return NRF_SPI_FREQ_2M;
} else if (frequency < 8000000) {
return NRF_SPI_FREQ_4M;
} else {
return NRF_SPI_FREQ_8M;
}
}
static inline nrf_spi_mode_t get_nrf_spi_mode(uint16_t operation)
{
if (SPI_MODE_GET(operation) & SPI_MODE_CPOL) {
if (SPI_MODE_GET(operation) & SPI_MODE_CPHA) {
return NRF_SPI_MODE_3;
} else {
return NRF_SPI_MODE_2;
}
} else {
if (SPI_MODE_GET(operation) & SPI_MODE_CPHA) {
return NRF_SPI_MODE_1;
} else {
return NRF_SPI_MODE_0;
}
}
}
static inline nrf_spi_bit_order_t get_nrf_spi_bit_order(uint16_t operation)
{
if (operation & SPI_TRANSFER_LSB) {
return NRF_SPI_BIT_ORDER_LSB_FIRST;
} else {
return NRF_SPI_BIT_ORDER_MSB_FIRST;
}
}
static int configure(const struct device *dev,
const struct spi_config *spi_cfg)
{
struct spi_nrfx_data *dev_data = dev->data;
const struct spi_nrfx_config *dev_config = dev->config;
struct spi_context *ctx = &dev_data->ctx;
nrfx_spi_config_t config;
nrfx_err_t result;
if (dev_data->initialized && spi_context_configured(ctx, spi_cfg)) {
/* Already configured. No need to do it again. */
return 0;
}
if (spi_cfg->operation & SPI_HALF_DUPLEX) {
LOG_ERR("Half-duplex not supported");
return -ENOTSUP;
}
if (SPI_OP_MODE_GET(spi_cfg->operation) != SPI_OP_MODE_MASTER) {
LOG_ERR("Slave mode is not supported on %s", dev->name);
return -EINVAL;
}
if (spi_cfg->operation & SPI_MODE_LOOP) {
LOG_ERR("Loopback mode is not supported");
return -EINVAL;
}
if (IS_ENABLED(CONFIG_SPI_EXTENDED_MODES) &&
(spi_cfg->operation & SPI_LINES_MASK) != SPI_LINES_SINGLE) {
LOG_ERR("Only single line mode is supported");
return -EINVAL;
}
if (SPI_WORD_SIZE_GET(spi_cfg->operation) != 8) {
LOG_ERR("Word sizes other than 8 bits are not supported");
return -EINVAL;
}
if (spi_cfg->frequency < 125000) {
LOG_ERR("Frequencies lower than 125 kHz are not supported");
return -EINVAL;
}
config = dev_config->def_config;
config.frequency = get_nrf_spi_frequency(spi_cfg->frequency);
config.mode = get_nrf_spi_mode(spi_cfg->operation);
config.bit_order = get_nrf_spi_bit_order(spi_cfg->operation);
nrf_gpio_pin_write(nrf_spi_sck_pin_get(dev_config->spi.p_reg),
spi_cfg->operation & SPI_MODE_CPOL ? 1 : 0);
if (dev_data->initialized) {
nrfx_spi_uninit(&dev_config->spi);
dev_data->initialized = false;
}
result = nrfx_spi_init(&dev_config->spi, &config,
event_handler, dev_data);
if (result != NRFX_SUCCESS) {
LOG_ERR("Failed to initialize nrfx driver: %08x", result);
return -EIO;
}
dev_data->initialized = true;
ctx->config = spi_cfg;
return 0;
}
static void finish_transaction(const struct device *dev, int error)
{
struct spi_nrfx_data *dev_data = dev->data;
struct spi_context *ctx = &dev_data->ctx;
LOG_DBG("Transaction finished with status %d", error);
spi_context_complete(ctx, dev, error);
dev_data->busy = false;
}
static void transfer_next_chunk(const struct device *dev)
{
const struct spi_nrfx_config *dev_config = dev->config;
struct spi_nrfx_data *dev_data = dev->data;
struct spi_context *ctx = &dev_data->ctx;
int error = 0;
size_t chunk_len = spi_context_max_continuous_chunk(ctx);
if (chunk_len > 0) {
nrfx_spi_xfer_desc_t xfer;
nrfx_err_t result;
dev_data->chunk_len = chunk_len;
xfer.p_tx_buffer = ctx->tx_buf;
xfer.tx_length = spi_context_tx_buf_on(ctx) ? chunk_len : 0;
xfer.p_rx_buffer = ctx->rx_buf;
xfer.rx_length = spi_context_rx_buf_on(ctx) ? chunk_len : 0;
result = nrfx_spi_xfer(&dev_config->spi, &xfer, 0);
if (result == NRFX_SUCCESS) {
return;
}
error = -EIO;
}
finish_transaction(dev, error);
}
static void event_handler(const nrfx_spi_evt_t *p_event, void *p_context)
{
struct spi_nrfx_data *dev_data = p_context;
if (p_event->type == NRFX_SPI_EVENT_DONE) {
/* Chunk length is set to 0 when a transaction is aborted
* due to a timeout.
*/
if (dev_data->chunk_len == 0) {
finish_transaction(dev_data->dev, -ETIMEDOUT);
return;
}
spi_context_update_tx(&dev_data->ctx, 1, dev_data->chunk_len);
spi_context_update_rx(&dev_data->ctx, 1, dev_data->chunk_len);
transfer_next_chunk(dev_data->dev);
}
}
static int transceive(const struct device *dev,
const struct spi_config *spi_cfg,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs,
bool asynchronous,
spi_callback_t cb,
void *userdata)
{
struct spi_nrfx_data *dev_data = dev->data;
const struct spi_nrfx_config *dev_config = dev->config;
int error;
spi_context_lock(&dev_data->ctx, asynchronous, cb, userdata, spi_cfg);
error = configure(dev, spi_cfg);
if (error == 0) {
dev_data->busy = true;
if (dev_config->wake_pin != WAKE_PIN_NOT_USED) {
error = spi_nrfx_wake_request(&dev_config->wake_gpiote,
dev_config->wake_pin);
if (error == -ETIMEDOUT) {
LOG_WRN("Waiting for WAKE acknowledgment timed out");
/* If timeout occurs, try to perform the transfer
* anyway, just in case the slave device was unable
* to signal that it was already awaken and prepared
* for the transfer.
*/
}
}
spi_context_buffers_setup(&dev_data->ctx, tx_bufs, rx_bufs, 1);
spi_context_cs_control(&dev_data->ctx, true);
transfer_next_chunk(dev);
error = spi_context_wait_for_completion(&dev_data->ctx);
if (error == -ETIMEDOUT) {
/* Set the chunk length to 0 so that event_handler()
* knows that the transaction timed out and is to be
* aborted.
*/
dev_data->chunk_len = 0;
/* Abort the current transfer by deinitializing
* the nrfx driver.
*/
nrfx_spi_uninit(&dev_config->spi);
dev_data->initialized = false;
/* Make sure the transaction is finished (it may be
* already finished if it actually did complete before
* the nrfx driver was deinitialized).
*/
finish_transaction(dev, -ETIMEDOUT);
/* Clean up the driver state. */
k_sem_reset(&dev_data->ctx.sync);
}
spi_context_cs_control(&dev_data->ctx, false);
}
spi_context_release(&dev_data->ctx, error);
return error;
}
static int spi_nrfx_transceive(const struct device *dev,
const struct spi_config *spi_cfg,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs)
{
return transceive(dev, spi_cfg, tx_bufs, rx_bufs, false, NULL, NULL);
}
#ifdef CONFIG_SPI_ASYNC
static int spi_nrfx_transceive_async(const struct device *dev,
const struct spi_config *spi_cfg,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs,
spi_callback_t cb,
void *userdata)
{
return transceive(dev, spi_cfg, tx_bufs, rx_bufs, true, cb, userdata);
}
#endif /* CONFIG_SPI_ASYNC */
static int spi_nrfx_release(const struct device *dev,
const struct spi_config *spi_cfg)
{
struct spi_nrfx_data *dev_data = dev->data;
if (!spi_context_configured(&dev_data->ctx, spi_cfg)) {
return -EINVAL;
}
if (dev_data->busy) {
return -EBUSY;
}
spi_context_unlock_unconditionally(&dev_data->ctx);
return 0;
}
static const struct spi_driver_api spi_nrfx_driver_api = {
.transceive = spi_nrfx_transceive,
#ifdef CONFIG_SPI_ASYNC
.transceive_async = spi_nrfx_transceive_async,
#endif
.release = spi_nrfx_release,
};
#ifdef CONFIG_PM_DEVICE
static int spi_nrfx_pm_action(const struct device *dev,
enum pm_device_action action)
{
int ret = 0;
struct spi_nrfx_data *dev_data = dev->data;
const struct spi_nrfx_config *dev_config = dev->config;
switch (action) {
case PM_DEVICE_ACTION_RESUME:
ret = pinctrl_apply_state(dev_config->pcfg,
PINCTRL_STATE_DEFAULT);
if (ret < 0) {
return ret;
}
/* nrfx_spi_init() will be called at configuration before
* the next transfer.
*/
break;
case PM_DEVICE_ACTION_SUSPEND:
if (dev_data->initialized) {
nrfx_spi_uninit(&dev_config->spi);
dev_data->initialized = false;
}
ret = pinctrl_apply_state(dev_config->pcfg,
PINCTRL_STATE_SLEEP);
if (ret < 0) {
return ret;
}
break;
default:
ret = -ENOTSUP;
}
return ret;
}
#endif /* CONFIG_PM_DEVICE */
static int spi_nrfx_init(const struct device *dev)
{
const struct spi_nrfx_config *dev_config = dev->config;
struct spi_nrfx_data *dev_data = dev->data;
int err;
err = pinctrl_apply_state(dev_config->pcfg, PINCTRL_STATE_DEFAULT);
if (err < 0) {
return err;
}
if (dev_config->wake_pin != WAKE_PIN_NOT_USED) {
err = spi_nrfx_wake_init(&dev_config->wake_gpiote, dev_config->wake_pin);
if (err == -ENODEV) {
LOG_ERR("Failed to allocate GPIOTE channel for WAKE");
return err;
}
if (err == -EIO) {
LOG_ERR("Failed to configure WAKE pin");
return err;
}
}
dev_config->irq_connect();
err = spi_context_cs_configure_all(&dev_data->ctx);
if (err < 0) {
return err;
}
spi_context_unlock_unconditionally(&dev_data->ctx);
return 0;
}
/*
* Current factors requiring use of DT_NODELABEL:
*
* - HAL design (requirement of drv_inst_idx in nrfx_spi_t)
* - Name-based HAL IRQ handlers, e.g. nrfx_spi_0_irq_handler
*/
#define SPI(idx) DT_NODELABEL(spi##idx)
#define SPI_PROP(idx, prop) DT_PROP(SPI(idx), prop)
#define SPI_NRFX_SPI_DEFINE(idx) \
NRF_DT_CHECK_NODE_HAS_PINCTRL_SLEEP(SPI(idx)); \
static void irq_connect##idx(void) \
{ \
IRQ_CONNECT(DT_IRQN(SPI(idx)), DT_IRQ(SPI(idx), priority), \
nrfx_isr, nrfx_spi_##idx##_irq_handler, 0); \
} \
static struct spi_nrfx_data spi_##idx##_data = { \
SPI_CONTEXT_INIT_LOCK(spi_##idx##_data, ctx), \
SPI_CONTEXT_INIT_SYNC(spi_##idx##_data, ctx), \
SPI_CONTEXT_CS_GPIOS_INITIALIZE(SPI(idx), ctx) \
.dev = DEVICE_DT_GET(SPI(idx)), \
.busy = false, \
}; \
PINCTRL_DT_DEFINE(SPI(idx)); \
static const struct spi_nrfx_config spi_##idx##z_config = { \
.spi = { \
.p_reg = (NRF_SPI_Type *)DT_REG_ADDR(SPI(idx)), \
.drv_inst_idx = NRFX_SPI##idx##_INST_IDX, \
}, \
.def_config = { \
.skip_gpio_cfg = true, \
.skip_psel_cfg = true, \
.ss_pin = NRFX_SPI_PIN_NOT_USED, \
.orc = SPI_PROP(idx, overrun_character), \
}, \
.irq_connect = irq_connect##idx, \
.pcfg = PINCTRL_DT_DEV_CONFIG_GET(SPI(idx)), \
.wake_pin = NRF_DT_GPIOS_TO_PSEL_OR(SPI(idx), wake_gpios, \
WAKE_PIN_NOT_USED), \
.wake_gpiote = WAKE_GPIOTE_INSTANCE(SPI(idx)), \
}; \
BUILD_ASSERT(!DT_NODE_HAS_PROP(SPI(idx), wake_gpios) || \
!(DT_GPIO_FLAGS(SPI(idx), wake_gpios) & GPIO_ACTIVE_LOW), \
"WAKE line must be configured as active high"); \
PM_DEVICE_DT_DEFINE(SPI(idx), spi_nrfx_pm_action); \
DEVICE_DT_DEFINE(SPI(idx), \
spi_nrfx_init, \
PM_DEVICE_DT_GET(SPI(idx)), \
&spi_##idx##_data, \
&spi_##idx##z_config, \
POST_KERNEL, CONFIG_SPI_INIT_PRIORITY, \
&spi_nrfx_driver_api)
#ifdef CONFIG_HAS_HW_NRF_SPI0
SPI_NRFX_SPI_DEFINE(0);
#endif
#ifdef CONFIG_HAS_HW_NRF_SPI1
SPI_NRFX_SPI_DEFINE(1);
#endif
#ifdef CONFIG_HAS_HW_NRF_SPI2
SPI_NRFX_SPI_DEFINE(2);
#endif
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