/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <errno.h>
#include <heap.h>
#include <string.h>
#include <cpu.h>
#include <spi.h>
#include <spi_priv.h>
#include <timer.h>
#define INFO_PRINT(fmt, ...) do { \
osLog(LOG_INFO, "%s " fmt, "[spi]", ##__VA_ARGS__); \
} while (0);
#define ERROR_PRINT(fmt, ...) do { \
osLog(LOG_ERROR, "%s " fmt, "[spi] ERROR:", ##__VA_ARGS__); \
} while (0);
struct SpiDeviceState {
struct SpiDevice dev;
const struct SpiPacket *packets;
size_t n;
size_t currentBuf;
struct SpiMode mode;
SpiCbkF rxTxCallback;
void *rxTxCookie;
SpiCbkF finishCallback;
void *finishCookie;
int err;
};
#define SPI_DEVICE_TO_STATE(p) ((struct SpiDeviceState *)p)
static void spiMasterNext(struct SpiDeviceState *state);
static void spiMasterStop(struct SpiDeviceState *state);
static void spiMasterDone(struct SpiDeviceState *state, int err);
static void spiSlaveNext(struct SpiDeviceState *state);
static void spiSlaveIdle(struct SpiDeviceState *state, int err);
static void spiSlaveDone(struct SpiDeviceState *state);
static int spiMasterStart(struct SpiDeviceState *state,
spi_cs_t cs, const struct SpiMode *mode)
{
struct SpiDevice *dev = &state->dev;
if (dev->ops->masterStartAsync)
return dev->ops->masterStartAsync(dev, cs, mode);
if (dev->ops->masterStartSync) {
int err = dev->ops->masterStartSync(dev, cs, mode);
if (err < 0)
return err;
}
return dev->ops->masterRxTx(dev, state->packets[0].rxBuf,
state->packets[0].txBuf, state->packets[0].size, mode);
}
void spi_masterStartAsync_done(struct SpiDevice *dev, int err)
{
struct SpiDeviceState *state = SPI_DEVICE_TO_STATE(dev);
if (err)
spiMasterDone(state, err);
else
spiMasterNext(state);
}
static void spiDelayCallback(uint32_t timerId, void *data)
{
spiMasterNext((struct SpiDeviceState *)data);
}
static void spiMasterNext(struct SpiDeviceState *state)
{
struct SpiDevice *dev = &state->dev;
if (state->currentBuf == state->n) {
spiMasterStop(state);
return;
}
size_t i = state->currentBuf;
void *rxBuf = state->packets[i].rxBuf;
const void *txBuf = state->packets[i].txBuf;
size_t size = state->packets[i].size;
const struct SpiMode *mode = &state->mode;
int err = dev->ops->masterRxTx(dev, rxBuf, txBuf, size, mode);
if (err)
spiMasterDone(state, err);
}
void spiMasterRxTxDone(struct SpiDevice *dev, int err)
{
struct SpiDeviceState *state = SPI_DEVICE_TO_STATE(dev);
if (err) {
spiMasterDone(state, err);
} else {
size_t i = state->currentBuf++;
if (state->packets[i].delay > 0) {
if (!timTimerSet(state->packets[i].delay, 0, 50, spiDelayCallback, state, true)) {
ERROR_PRINT("Cannot do delayed spi, timer depleted\n");
spiMasterDone(state, -ENOMEM); // should be out of timer; out of mem is close enough
}
} else {
spiMasterNext(state);
}
}
}
static void spiMasterStop(struct SpiDeviceState *state)
{
struct SpiDevice *dev = &state->dev;
if (dev->ops->masterStopSync) {
int err = dev->ops->masterStopSync(dev);
spiMasterDone(state, err);
} else if (dev->ops->masterStopAsync) {
int err = dev->ops->masterStopAsync(dev);
if (err < 0)
spiMasterDone(state, err);
} else {
spiMasterDone(state, 0);
}
}
void spiMasterStopAsyncDone(struct SpiDevice *dev, int err)
{
struct SpiDeviceState *state = SPI_DEVICE_TO_STATE(dev);
spiMasterDone(state, err);
}
static void spiMasterDone(struct SpiDeviceState *state, int err)
{
SpiCbkF callback = state->rxTxCallback;
void *cookie = state->rxTxCookie;
callback(cookie, err);
}
static int spiSlaveStart(struct SpiDeviceState *state,
const struct SpiMode *mode)
{
struct SpiDevice *dev = &state->dev;
if (dev->ops->slaveStartAsync)
return dev->ops->slaveStartAsync(dev, mode);
if (dev->ops->slaveStartSync) {
int err = dev->ops->slaveStartSync(dev, mode);
if (err < 0)
return err;
}
return dev->ops->slaveIdle(dev, mode);
}
void spiSlaveStartAsyncDone(struct SpiDevice *dev, int err)
{
struct SpiDeviceState *state = SPI_DEVICE_TO_STATE(dev);
if (err)
state->err = err;
else
state->err = dev->ops->slaveIdle(dev, &state->mode);
}
void spiSlaveRxTxDone(struct SpiDevice *dev, int err)
{
struct SpiDeviceState *state = SPI_DEVICE_TO_STATE(dev);
if (err) {
spiSlaveIdle(state, err);
} else {
state->currentBuf++;
spiSlaveNext(state);
}
}
void spiSlaveCsInactive(struct SpiDevice *dev)
{
struct SpiDeviceState *state = SPI_DEVICE_TO_STATE(dev);
dev->ops->slaveSetCsInterrupt(dev, false);
if (!state->finishCallback) {
osLog(LOG_WARN, "%s called without callback\n", __func__);
return;
}
SpiCbkF callback = state->finishCallback;
void *cookie = state->finishCookie;
state->finishCallback = NULL;
state->finishCookie = NULL;
callback(cookie, 0);
}
static void spiSlaveNext(struct SpiDeviceState *state)
{
struct SpiDevice *dev = &state->dev;
if (state->currentBuf == state->n) {
spiSlaveIdle(state, 0);
return;
}
size_t i = state->currentBuf;
void *rxBuf = state->packets[i].rxBuf;
const void *txBuf = state->packets[i].txBuf;
size_t size = state->packets[i].size;
const struct SpiMode *mode = &state->mode;
int err = dev->ops->slaveRxTx(dev, rxBuf, txBuf, size, mode);
if (err)
spiSlaveIdle(state, err);
}
static void spiSlaveIdle(struct SpiDeviceState *state, int err)
{
struct SpiDevice *dev = &state->dev;
SpiCbkF callback = state->rxTxCallback;
void *cookie = state->rxTxCookie;
if (!err)
err = dev->ops->slaveIdle(dev, &state->mode);
callback(cookie, err);
}
void spiSlaveStopAsyncDone(struct SpiDevice *dev, int err)
{
struct SpiDeviceState *state = SPI_DEVICE_TO_STATE(dev);
spiSlaveDone(state);
}
static void spiSlaveDone(struct SpiDeviceState *state)
{
struct SpiDevice *dev = &state->dev;
if (dev->ops->release)
dev->ops->release(dev);
heapFree(state);
}
static int spiSetupRxTx(struct SpiDeviceState *state,
const struct SpiPacket packets[], size_t n,
SpiCbkF callback, void *cookie)
{
state->packets = packets;
state->n = n;
state->currentBuf = 0;
state->rxTxCallback = callback;
state->rxTxCookie = cookie;
return 0;
}
int spiMasterRequest(uint8_t busId, struct SpiDevice **dev_out)
{
int ret = 0;
struct SpiDeviceState *state = heapAlloc(sizeof(*state));
if (!state)
return -ENOMEM;
struct SpiDevice *dev = &state->dev;
ret = spiRequest(dev, busId);
if (ret < 0)
goto err_request;
if (!dev->ops->masterRxTx) {
ret = -EOPNOTSUPP;
goto err_opsupp;
}
*dev_out = dev;
return 0;
err_opsupp:
if (dev->ops->release)
dev->ops->release(dev);
err_request:
heapFree(state);
return ret;
}
int spiMasterRxTx(struct SpiDevice *dev, spi_cs_t cs,
const struct SpiPacket packets[], size_t n,
const struct SpiMode *mode, SpiCbkF callback,
void *cookie)
{
struct SpiDeviceState *state = SPI_DEVICE_TO_STATE(dev);
int ret = 0;
if (!n)
return -EINVAL;
ret = spiSetupRxTx(state, packets, n, callback, cookie);
if (ret < 0)
return ret;
state->mode = *mode;
return spiMasterStart(state, cs, mode);
}
int spiMasterRelease(struct SpiDevice *dev)
{
struct SpiDeviceState *state = SPI_DEVICE_TO_STATE(dev);
if (dev->ops->release) {
int ret = dev->ops->release(dev);
if (ret < 0)
return ret;
}
heapFree(state);
return 0;
}
int spiSlaveRequest(uint8_t busId, const struct SpiMode *mode,
struct SpiDevice **dev_out)
{
int ret = 0;
struct SpiDeviceState *state = heapAlloc(sizeof(*state));
if (!state)
return -ENOMEM;
struct SpiDevice *dev = &state->dev;
ret = spiRequest(dev, busId);
if (ret < 0)
goto err_request;
if (!dev->ops->slaveIdle || !dev->ops->slaveRxTx) {
ret = -EOPNOTSUPP;
goto err_opsupp;
}
state->mode = *mode;
state->err = 0;
ret = spiSlaveStart(state, mode);
if (ret < 0)
goto err_opsupp;
*dev_out = dev;
return 0;
err_opsupp:
if (dev->ops->release)
dev->ops->release(dev);
err_request:
heapFree(state);
return ret;
}
int spiSlaveRxTx(struct SpiDevice *dev,
const struct SpiPacket packets[], size_t n,
SpiCbkF callback, void *cookie)
{
struct SpiDeviceState *state = SPI_DEVICE_TO_STATE(dev);
if (!n)
return -EINVAL;
if (state->err)
return state->err;
int ret = spiSetupRxTx(state, packets, n, callback, cookie);
if (ret < 0)
return ret;
return dev->ops->slaveRxTx(dev, state->packets[0].rxBuf,
state->packets[0].txBuf, state->packets[0].size, &state->mode);
}
int spiSlaveWaitForInactive(struct SpiDevice *dev, SpiCbkF callback,
void *cookie)
{
struct SpiDeviceState *state = SPI_DEVICE_TO_STATE(dev);
if (!dev->ops->slaveSetCsInterrupt || !dev->ops->slaveCsIsActive)
return -EOPNOTSUPP;
state->finishCallback = callback;
state->finishCookie = cookie;
uint64_t flags = cpuIntsOff();
dev->ops->slaveSetCsInterrupt(dev, true);
/* CS may already be inactive before enabling the interrupt. In this case
* roll back and fire the callback immediately.
*
* Interrupts must be off while checking for this. Otherwise there is a
* (very unlikely) race where the CS interrupt fires between calling
* slaveSetCsInterrupt(true) and the rollback
* slaveSetCsInterrupt(false), causing the event to be handled twice.
*
* Likewise the check must come after enabling the interrupt. Otherwise
* there is an (also unlikely) race where CS goes inactive between reading
* CS and enabling the interrupt, causing the event to be lost.
*/
bool cs = dev->ops->slaveCsIsActive(dev);
if (!cs) {
dev->ops->slaveSetCsInterrupt(dev, false);
cpuIntsRestore(flags);
state->finishCallback = NULL;
state->finishCookie = NULL;
callback(cookie, 0);
return 0;
}
cpuIntsRestore(flags);
return 0;
}
int spiSlaveRelease(struct SpiDevice *dev)
{
struct SpiDeviceState *state = SPI_DEVICE_TO_STATE(dev);
int ret;
if (dev->ops->slaveStopSync) {
ret = dev->ops->slaveStopSync(dev);
if (ret < 0)
return ret;
} else if (dev->ops->slaveStopAsync) {
return dev->ops->slaveStopAsync(dev);
}
spiSlaveDone(state);
return 0;
}