133 lines
3.9 KiB
C
133 lines
3.9 KiB
C
/*
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* Copyright 2020 Google LLC
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* This driver creates fake SPI buses which can contain emulated devices,
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* implemented by a separate emulation driver. The API between this driver and
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* its emulators is defined by struct spi_emul_driver_api.
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*/
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#define DT_DRV_COMPAT zephyr_spi_emul_controller
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#define LOG_LEVEL CONFIG_SPI_LOG_LEVEL
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#include <zephyr/logging/log.h>
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LOG_MODULE_REGISTER(spi_emul_ctlr);
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#include <zephyr/device.h>
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#include <zephyr/drivers/emul.h>
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#include <zephyr/drivers/spi.h>
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#include <zephyr/drivers/spi_emul.h>
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/** Working data for the device */
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struct spi_emul_data {
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/* List of struct spi_emul associated with the device */
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sys_slist_t emuls;
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/* SPI host configuration */
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uint32_t config;
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};
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uint32_t spi_emul_get_config(const struct device *dev)
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{
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struct spi_emul_data *data = dev->data;
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return data->config;
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}
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/**
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* Find an emulator for a SPI bus
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*
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* At present only a single emulator is supported on the bus, since we do not
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* support chip selects, despite there being a chipsel field. It cannot be
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* implemented until we have a GPIO emulator.
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*
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* @param dev SPI emulation controller device
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* @param chipsel Chip-select value
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* @return emulator to use
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* @return NULL if not found
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*/
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static struct spi_emul *spi_emul_find(const struct device *dev, unsigned int chipsel)
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{
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struct spi_emul_data *data = dev->data;
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sys_snode_t *node;
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SYS_SLIST_FOR_EACH_NODE(&data->emuls, node) {
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struct spi_emul *emul;
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emul = CONTAINER_OF(node, struct spi_emul, node);
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if (emul->chipsel == chipsel) {
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return emul;
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}
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}
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return NULL;
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}
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static int spi_emul_io(const struct device *dev, const struct spi_config *config,
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const struct spi_buf_set *tx_bufs, const struct spi_buf_set *rx_bufs)
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{
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struct spi_emul *emul;
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const struct spi_emul_api *api;
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emul = spi_emul_find(dev, config->slave);
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if (!emul) {
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return -EIO;
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}
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api = emul->api;
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__ASSERT_NO_MSG(emul->api);
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__ASSERT_NO_MSG(emul->api->io);
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return api->io(emul->target, config, tx_bufs, rx_bufs);
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}
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/**
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* Set up a new emulator and add it to the list
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*
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* @param dev SPI emulation controller device
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*/
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static int spi_emul_init(const struct device *dev)
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{
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struct spi_emul_data *data = dev->data;
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sys_slist_init(&data->emuls);
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return emul_init_for_bus(dev);
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}
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int spi_emul_register(const struct device *dev, struct spi_emul *emul)
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{
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struct spi_emul_data *data = dev->data;
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const char *name = emul->target->dev->name;
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sys_slist_append(&data->emuls, &emul->node);
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LOG_INF("Register emulator '%s' at cs %u\n", name, emul->chipsel);
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return 0;
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}
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/* Device instantiation */
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static struct spi_driver_api spi_emul_api = {
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.transceive = spi_emul_io,
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};
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#define EMUL_LINK_AND_COMMA(node_id) \
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{ \
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.dev = DEVICE_DT_GET(node_id), \
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},
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#define SPI_EMUL_INIT(n) \
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static const struct emul_link_for_bus emuls_##n[] = { DT_FOREACH_CHILD( \
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DT_DRV_INST(0), EMUL_LINK_AND_COMMA) }; \
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static struct emul_list_for_bus spi_emul_cfg_##n = { \
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.children = emuls_##n, \
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.num_children = ARRAY_SIZE(emuls_##n), \
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}; \
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static struct spi_emul_data spi_emul_data_##n; \
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DEVICE_DT_INST_DEFINE(n, spi_emul_init, NULL, &spi_emul_data_##n, &spi_emul_cfg_##n, \
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POST_KERNEL, CONFIG_SPI_INIT_PRIORITY, &spi_emul_api);
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DT_INST_FOREACH_STATUS_OKAY(SPI_EMUL_INIT)
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