blob: 16b64639f96754f59d626cdb84a3b90c8c2b35c7 [file] [log] [blame] [edit]
/*
* Copyright (c) 2017 Google LLC.
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT atmel_sam0_spi
#define LOG_LEVEL CONFIG_SPI_LOG_LEVEL
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(spi_sam0);
#include "spi_context.h"
#include <errno.h>
#include <zephyr/device.h>
#include <zephyr/drivers/spi.h>
#include <zephyr/drivers/dma.h>
#include <zephyr/drivers/pinctrl.h>
#include <soc.h>
#ifndef SERCOM_SPI_CTRLA_MODE_SPI_MASTER_Val
#define SERCOM_SPI_CTRLA_MODE_SPI_MASTER_Val (0x3)
#endif
/* Device constant configuration parameters */
struct spi_sam0_config {
SercomSpi *regs;
uint32_t pads;
const struct pinctrl_dev_config *pcfg;
#ifdef MCLK
volatile uint32_t *mclk;
uint32_t mclk_mask;
uint16_t gclk_core_id;
#else
uint32_t pm_apbcmask;
uint16_t gclk_clkctrl_id;
#endif
#ifdef CONFIG_SPI_ASYNC
const struct device *dma_dev;
uint8_t tx_dma_request;
uint8_t tx_dma_channel;
uint8_t rx_dma_request;
uint8_t rx_dma_channel;
#endif
};
/* Device run time data */
struct spi_sam0_data {
struct spi_context ctx;
#ifdef CONFIG_SPI_ASYNC
const struct device *dev;
uint32_t dma_segment_len;
#endif
};
static void wait_synchronization(SercomSpi *regs)
{
#if defined(SERCOM_SPI_SYNCBUSY_MASK)
/* SYNCBUSY is a register */
while ((regs->SYNCBUSY.reg & SERCOM_SPI_SYNCBUSY_MASK) != 0) {
}
#elif defined(SERCOM_SPI_STATUS_SYNCBUSY)
/* SYNCBUSY is a bit */
while ((regs->STATUS.reg & SERCOM_SPI_STATUS_SYNCBUSY) != 0) {
}
#else
#error Unsupported device
#endif
}
static int spi_sam0_configure(const struct device *dev,
const struct spi_config *config)
{
const struct spi_sam0_config *cfg = dev->config;
struct spi_sam0_data *data = dev->data;
SercomSpi *regs = cfg->regs;
SERCOM_SPI_CTRLA_Type ctrla = {.reg = 0};
SERCOM_SPI_CTRLB_Type ctrlb = {.reg = 0};
int div;
if (spi_context_configured(&data->ctx, config)) {
return 0;
}
if (config->operation & SPI_HALF_DUPLEX) {
LOG_ERR("Half-duplex not supported");
return -ENOTSUP;
}
if (SPI_OP_MODE_GET(config->operation) != SPI_OP_MODE_MASTER) {
/* Slave mode is not implemented. */
return -ENOTSUP;
}
ctrla.bit.MODE = SERCOM_SPI_CTRLA_MODE_SPI_MASTER_Val;
if ((config->operation & SPI_TRANSFER_LSB) != 0U) {
ctrla.bit.DORD = 1;
}
if ((config->operation & SPI_MODE_CPOL) != 0U) {
ctrla.bit.CPOL = 1;
}
if ((config->operation & SPI_MODE_CPHA) != 0U) {
ctrla.bit.CPHA = 1;
}
ctrla.reg |= cfg->pads;
if ((config->operation & SPI_MODE_LOOP) != 0U) {
/* Put MISO and MOSI on the same pad */
ctrla.bit.DOPO = 0;
ctrla.bit.DIPO = 0;
}
ctrla.bit.ENABLE = 1;
ctrlb.bit.RXEN = 1;
if (SPI_WORD_SIZE_GET(config->operation) != 8) {
return -ENOTSUP;
}
/* 8 bits per transfer */
ctrlb.bit.CHSIZE = 0;
/* Use the requested or next highest possible frequency */
div = (SOC_ATMEL_SAM0_GCLK0_FREQ_HZ / config->frequency) / 2U - 1;
div = CLAMP(div, 0, UINT8_MAX);
/* Update the configuration only if it has changed */
if (regs->CTRLA.reg != ctrla.reg || regs->CTRLB.reg != ctrlb.reg ||
regs->BAUD.reg != div) {
regs->CTRLA.bit.ENABLE = 0;
wait_synchronization(regs);
regs->CTRLB = ctrlb;
wait_synchronization(regs);
regs->BAUD.reg = div;
wait_synchronization(regs);
regs->CTRLA = ctrla;
wait_synchronization(regs);
}
data->ctx.config = config;
return 0;
}
static bool spi_sam0_transfer_ongoing(struct spi_sam0_data *data)
{
return spi_context_tx_on(&data->ctx) || spi_context_rx_on(&data->ctx);
}
static void spi_sam0_shift_master(SercomSpi *regs, struct spi_sam0_data *data)
{
uint8_t tx;
uint8_t rx;
if (spi_context_tx_buf_on(&data->ctx)) {
tx = *(uint8_t *)(data->ctx.tx_buf);
} else {
tx = 0U;
}
while (!regs->INTFLAG.bit.DRE) {
}
regs->DATA.reg = tx;
spi_context_update_tx(&data->ctx, 1, 1);
while (!regs->INTFLAG.bit.RXC) {
}
rx = regs->DATA.reg;
if (spi_context_rx_buf_on(&data->ctx)) {
*data->ctx.rx_buf = rx;
}
spi_context_update_rx(&data->ctx, 1, 1);
}
/* Finish any ongoing writes and drop any remaining read data */
static void spi_sam0_finish(SercomSpi *regs)
{
while (!regs->INTFLAG.bit.TXC) {
}
while (regs->INTFLAG.bit.RXC) {
(void)regs->DATA.reg;
}
}
/* Fast path that transmits a buf */
static void spi_sam0_fast_tx(SercomSpi *regs, const struct spi_buf *tx_buf)
{
const uint8_t *p = tx_buf->buf;
const uint8_t *pend = (uint8_t *)tx_buf->buf + tx_buf->len;
uint8_t ch;
while (p != pend) {
ch = *p++;
while (!regs->INTFLAG.bit.DRE) {
}
regs->DATA.reg = ch;
}
spi_sam0_finish(regs);
}
/* Fast path that reads into a buf */
static void spi_sam0_fast_rx(SercomSpi *regs, const struct spi_buf *rx_buf)
{
uint8_t *rx = rx_buf->buf;
int len = rx_buf->len;
if (len <= 0) {
return;
}
while (len) {
/* Send the next byte */
regs->DATA.reg = 0;
len--;
/* Wait for completion, and read */
while (!regs->INTFLAG.bit.RXC) {
}
*rx++ = regs->DATA.reg;
}
spi_sam0_finish(regs);
}
/* Fast path that writes and reads bufs of the same length */
static void spi_sam0_fast_txrx(SercomSpi *regs,
const struct spi_buf *tx_buf,
const struct spi_buf *rx_buf)
{
const uint8_t *tx = tx_buf->buf;
const uint8_t *txend = (uint8_t *)tx_buf->buf + tx_buf->len;
uint8_t *rx = rx_buf->buf;
size_t len = rx_buf->len;
if (len == 0) {
return;
}
while (tx != txend) {
/* Send the next byte */
regs->DATA.reg = *tx++;
/* Wait for completion, and read */
while (!regs->INTFLAG.bit.RXC) {
}
*rx++ = regs->DATA.reg;
}
spi_sam0_finish(regs);
}
/* Fast path where every overlapping tx and rx buffer is the same length */
static void spi_sam0_fast_transceive(const struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs)
{
const struct spi_sam0_config *cfg = dev->config;
size_t tx_count = 0;
size_t rx_count = 0;
SercomSpi *regs = cfg->regs;
const struct spi_buf *tx = NULL;
const struct spi_buf *rx = NULL;
if (tx_bufs) {
tx = tx_bufs->buffers;
tx_count = tx_bufs->count;
}
if (rx_bufs) {
rx = rx_bufs->buffers;
rx_count = rx_bufs->count;
} else {
rx = NULL;
}
while (tx_count != 0 && rx_count != 0) {
if (tx->buf == NULL) {
spi_sam0_fast_rx(regs, rx);
} else if (rx->buf == NULL) {
spi_sam0_fast_tx(regs, tx);
} else {
spi_sam0_fast_txrx(regs, tx, rx);
}
tx++;
tx_count--;
rx++;
rx_count--;
}
for (; tx_count != 0; tx_count--) {
spi_sam0_fast_tx(regs, tx++);
}
for (; rx_count != 0; rx_count--) {
spi_sam0_fast_rx(regs, rx++);
}
}
/* Returns true if the request is suitable for the fast
* path. Specifically, the bufs are a sequence of:
*
* - Zero or more RX and TX buf pairs where each is the same length.
* - Zero or more trailing RX only bufs
* - Zero or more trailing TX only bufs
*/
static bool spi_sam0_is_regular(const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs)
{
const struct spi_buf *tx = NULL;
const struct spi_buf *rx = NULL;
size_t tx_count = 0;
size_t rx_count = 0;
if (tx_bufs) {
tx = tx_bufs->buffers;
tx_count = tx_bufs->count;
}
if (rx_bufs) {
rx = rx_bufs->buffers;
rx_count = rx_bufs->count;
}
while (tx_count != 0 && rx_count != 0) {
if (tx->len != rx->len) {
return false;
}
tx++;
tx_count--;
rx++;
rx_count--;
}
return true;
}
static int spi_sam0_transceive(const struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs)
{
const struct spi_sam0_config *cfg = dev->config;
struct spi_sam0_data *data = dev->data;
SercomSpi *regs = cfg->regs;
int err;
spi_context_lock(&data->ctx, false, NULL, NULL, config);
err = spi_sam0_configure(dev, config);
if (err != 0) {
goto done;
}
spi_context_cs_control(&data->ctx, true);
/* This driver special cases the common send only, receive
* only, and transmit then receive operations. This special
* casing is 4x faster than the spi_context() routines
* and allows the transmit and receive to be interleaved.
*/
if (spi_sam0_is_regular(tx_bufs, rx_bufs)) {
spi_sam0_fast_transceive(dev, config, tx_bufs, rx_bufs);
} else {
spi_context_buffers_setup(&data->ctx, tx_bufs, rx_bufs, 1);
do {
spi_sam0_shift_master(regs, data);
} while (spi_sam0_transfer_ongoing(data));
}
spi_context_cs_control(&data->ctx, false);
done:
spi_context_release(&data->ctx, err);
return err;
}
static int spi_sam0_transceive_sync(const struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs)
{
return spi_sam0_transceive(dev, config, tx_bufs, rx_bufs);
}
#ifdef CONFIG_SPI_ASYNC
static void spi_sam0_dma_rx_done(const struct device *dma_dev, void *arg,
uint32_t id, int error_code);
static int spi_sam0_dma_rx_load(const struct device *dev, uint8_t *buf,
size_t len)
{
const struct spi_sam0_config *cfg = dev->config;
struct spi_sam0_data *data = dev->data;
SercomSpi *regs = cfg->regs;
struct dma_config dma_cfg = { 0 };
struct dma_block_config dma_blk = { 0 };
int retval;
dma_cfg.channel_direction = PERIPHERAL_TO_MEMORY;
dma_cfg.source_data_size = 1;
dma_cfg.dest_data_size = 1;
dma_cfg.user_data = data;
dma_cfg.dma_callback = spi_sam0_dma_rx_done;
dma_cfg.block_count = 1;
dma_cfg.head_block = &dma_blk;
dma_cfg.dma_slot = cfg->rx_dma_request;
dma_blk.block_size = len;
if (buf != NULL) {
dma_blk.dest_address = (uint32_t)buf;
} else {
static uint8_t dummy;
dma_blk.dest_address = (uint32_t)&dummy;
dma_blk.dest_addr_adj = DMA_ADDR_ADJ_NO_CHANGE;
}
dma_blk.source_address = (uint32_t)(&(regs->DATA.reg));
dma_blk.source_addr_adj = DMA_ADDR_ADJ_NO_CHANGE;
retval = dma_config(cfg->dma_dev, cfg->rx_dma_channel,
&dma_cfg);
if (retval != 0) {
return retval;
}
return dma_start(cfg->dma_dev, cfg->rx_dma_channel);
}
static int spi_sam0_dma_tx_load(const struct device *dev, const uint8_t *buf,
size_t len)
{
const struct spi_sam0_config *cfg = dev->config;
SercomSpi *regs = cfg->regs;
struct dma_config dma_cfg = { 0 };
struct dma_block_config dma_blk = { 0 };
int retval;
dma_cfg.channel_direction = PERIPHERAL_TO_MEMORY;
dma_cfg.source_data_size = 1;
dma_cfg.dest_data_size = 1;
dma_cfg.block_count = 1;
dma_cfg.head_block = &dma_blk;
dma_cfg.dma_slot = cfg->tx_dma_request;
dma_blk.block_size = len;
if (buf != NULL) {
dma_blk.source_address = (uint32_t)buf;
} else {
static const uint8_t dummy;
dma_blk.source_address = (uint32_t)&dummy;
dma_blk.source_addr_adj = DMA_ADDR_ADJ_NO_CHANGE;
}
dma_blk.dest_address = (uint32_t)(&(regs->DATA.reg));
dma_blk.dest_addr_adj = DMA_ADDR_ADJ_NO_CHANGE;
retval = dma_config(cfg->dma_dev, cfg->tx_dma_channel,
&dma_cfg);
if (retval != 0) {
return retval;
}
return dma_start(cfg->dma_dev, cfg->tx_dma_channel);
}
static bool spi_sam0_dma_advance_segment(const struct device *dev)
{
struct spi_sam0_data *data = dev->data;
uint32_t segment_len;
/* Pick the shorter buffer of ones that have an actual length */
if (data->ctx.rx_len != 0) {
segment_len = data->ctx.rx_len;
if (data->ctx.tx_len != 0) {
segment_len = MIN(segment_len, data->ctx.tx_len);
}
} else {
segment_len = data->ctx.tx_len;
}
if (segment_len == 0) {
return false;
}
segment_len = MIN(segment_len, 65535);
data->dma_segment_len = segment_len;
return true;
}
static int spi_sam0_dma_advance_buffers(const struct device *dev)
{
struct spi_sam0_data *data = dev->data;
int retval;
if (data->dma_segment_len == 0) {
return -EINVAL;
}
/* Load receive first, so it can accept transmit data */
if (data->ctx.rx_len) {
retval = spi_sam0_dma_rx_load(dev, data->ctx.rx_buf,
data->dma_segment_len);
} else {
retval = spi_sam0_dma_rx_load(dev, NULL, data->dma_segment_len);
}
if (retval != 0) {
return retval;
}
/* Now load the transmit, which starts the actual bus clocking */
if (data->ctx.tx_len) {
retval = spi_sam0_dma_tx_load(dev, data->ctx.tx_buf,
data->dma_segment_len);
} else {
retval = spi_sam0_dma_tx_load(dev, NULL, data->dma_segment_len);
}
if (retval != 0) {
return retval;
}
return 0;
}
static void spi_sam0_dma_rx_done(const struct device *dma_dev, void *arg,
uint32_t id, int error_code)
{
struct spi_sam0_data *data = arg;
const struct device *dev = data->dev;
const struct spi_sam0_config *cfg = dev->config;
int retval;
ARG_UNUSED(id);
ARG_UNUSED(error_code);
spi_context_update_tx(&data->ctx, 1, data->dma_segment_len);
spi_context_update_rx(&data->ctx, 1, data->dma_segment_len);
if (!spi_sam0_dma_advance_segment(dev)) {
/* Done */
spi_context_cs_control(&data->ctx, false);
spi_context_complete(&data->ctx, dev, 0);
return;
}
retval = spi_sam0_dma_advance_buffers(dev);
if (retval != 0) {
dma_stop(cfg->dma_dev, cfg->tx_dma_channel);
dma_stop(cfg->dma_dev, cfg->rx_dma_channel);
spi_context_cs_control(&data->ctx, false);
spi_context_complete(&data->ctx, dev, retval);
return;
}
}
static int spi_sam0_transceive_async(const struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs,
spi_callback_t cb,
void *userdata)
{
const struct spi_sam0_config *cfg = dev->config;
struct spi_sam0_data *data = dev->data;
int retval;
/*
* Transmit clocks the output and we use receive to determine when
* the transmit is done, so we always need both
*/
if (cfg->tx_dma_channel == 0xFF || cfg->rx_dma_channel == 0xFF) {
return -ENOTSUP;
}
spi_context_lock(&data->ctx, true, cb, userdata, config);
retval = spi_sam0_configure(dev, config);
if (retval != 0) {
goto err_unlock;
}
spi_context_cs_control(&data->ctx, true);
spi_context_buffers_setup(&data->ctx, tx_bufs, rx_bufs, 1);
spi_sam0_dma_advance_segment(dev);
retval = spi_sam0_dma_advance_buffers(dev);
if (retval != 0) {
goto err_cs;
}
return 0;
err_cs:
dma_stop(cfg->dma_dev, cfg->tx_dma_channel);
dma_stop(cfg->dma_dev, cfg->rx_dma_channel);
spi_context_cs_control(&data->ctx, false);
err_unlock:
spi_context_release(&data->ctx, retval);
return retval;
}
#endif /* CONFIG_SPI_ASYNC */
static int spi_sam0_release(const struct device *dev,
const struct spi_config *config)
{
struct spi_sam0_data *data = dev->data;
spi_context_unlock_unconditionally(&data->ctx);
return 0;
}
static int spi_sam0_init(const struct device *dev)
{
int err;
const struct spi_sam0_config *cfg = dev->config;
struct spi_sam0_data *data = dev->data;
SercomSpi *regs = cfg->regs;
#ifdef MCLK
/* Enable the GCLK */
GCLK->PCHCTRL[cfg->gclk_core_id].reg = GCLK_PCHCTRL_GEN_GCLK0 |
GCLK_PCHCTRL_CHEN;
/* Enable the MCLK */
*cfg->mclk |= cfg->mclk_mask;
#else
/* Enable the GCLK */
GCLK->CLKCTRL.reg = cfg->gclk_clkctrl_id | GCLK_CLKCTRL_GEN_GCLK0 |
GCLK_CLKCTRL_CLKEN;
/* Enable SERCOM clock in PM */
PM->APBCMASK.reg |= cfg->pm_apbcmask;
#endif
/* Disable all SPI interrupts */
regs->INTENCLR.reg = SERCOM_SPI_INTENCLR_MASK;
wait_synchronization(regs);
err = pinctrl_apply_state(cfg->pcfg, PINCTRL_STATE_DEFAULT);
if (err < 0) {
return err;
}
#ifdef CONFIG_SPI_ASYNC
if (!device_is_ready(cfg->dma_dev)) {
return -ENODEV;
}
data->dev = dev;
#endif
err = spi_context_cs_configure_all(&data->ctx);
if (err < 0) {
return err;
}
spi_context_unlock_unconditionally(&data->ctx);
/* The device will be configured and enabled when transceive
* is called.
*/
return 0;
}
static const struct spi_driver_api spi_sam0_driver_api = {
.transceive = spi_sam0_transceive_sync,
#ifdef CONFIG_SPI_ASYNC
.transceive_async = spi_sam0_transceive_async,
#endif
.release = spi_sam0_release,
};
#if CONFIG_SPI_ASYNC
#define SPI_SAM0_DMA_CHANNELS(n) \
.dma_dev = DEVICE_DT_GET(ATMEL_SAM0_DT_INST_DMA_CTLR(n, tx)), \
.tx_dma_request = ATMEL_SAM0_DT_INST_DMA_TRIGSRC(n, tx), \
.tx_dma_channel = ATMEL_SAM0_DT_INST_DMA_CHANNEL(n, tx), \
.rx_dma_request = ATMEL_SAM0_DT_INST_DMA_TRIGSRC(n, rx), \
.rx_dma_channel = ATMEL_SAM0_DT_INST_DMA_CHANNEL(n, rx),
#else
#define SPI_SAM0_DMA_CHANNELS(n)
#endif
#define SPI_SAM0_SERCOM_PADS(n) \
SERCOM_SPI_CTRLA_DIPO(DT_INST_PROP(n, dipo)) | \
SERCOM_SPI_CTRLA_DOPO(DT_INST_PROP(n, dopo))
#ifdef MCLK
#define SPI_SAM0_DEFINE_CONFIG(n) \
static const struct spi_sam0_config spi_sam0_config_##n = { \
.regs = (SercomSpi *)DT_INST_REG_ADDR(n), \
.mclk = (volatile uint32_t *)MCLK_MASK_DT_INT_REG_ADDR(n), \
.mclk_mask = BIT(DT_INST_CLOCKS_CELL_BY_NAME(n, mclk, bit)), \
.gclk_core_id = DT_INST_CLOCKS_CELL_BY_NAME(n, gclk, periph_ch),\
.pads = SPI_SAM0_SERCOM_PADS(n), \
.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(n), \
SPI_SAM0_DMA_CHANNELS(n) \
}
#else
#define SPI_SAM0_DEFINE_CONFIG(n) \
static const struct spi_sam0_config spi_sam0_config_##n = { \
.regs = (SercomSpi *)DT_INST_REG_ADDR(n), \
.pm_apbcmask = BIT(DT_INST_CLOCKS_CELL_BY_NAME(n, pm, bit)), \
.gclk_clkctrl_id = DT_INST_CLOCKS_CELL_BY_NAME(n, gclk, clkctrl_id),\
.pads = SPI_SAM0_SERCOM_PADS(n), \
.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(n), \
SPI_SAM0_DMA_CHANNELS(n) \
}
#endif /* MCLK */
#define SPI_SAM0_DEVICE_INIT(n) \
PINCTRL_DT_INST_DEFINE(n); \
SPI_SAM0_DEFINE_CONFIG(n); \
static struct spi_sam0_data spi_sam0_dev_data_##n = { \
SPI_CONTEXT_INIT_LOCK(spi_sam0_dev_data_##n, ctx), \
SPI_CONTEXT_INIT_SYNC(spi_sam0_dev_data_##n, ctx), \
SPI_CONTEXT_CS_GPIOS_INITIALIZE(DT_DRV_INST(n), ctx) \
}; \
DEVICE_DT_INST_DEFINE(n, &spi_sam0_init, NULL, \
&spi_sam0_dev_data_##n, \
&spi_sam0_config_##n, POST_KERNEL, \
CONFIG_SPI_INIT_PRIORITY, \
&spi_sam0_driver_api);
DT_INST_FOREACH_STATUS_OKAY(SPI_SAM0_DEVICE_INIT)