/**
* spi_mem_supports_op() - Check if a memory device and the controller it is
* connected to support a specific memory operation
* @mem: the SPI memory
* @op: the memory operation to check
*
* Some controllers are only supporting Single or Dual IOs, others might only
* support specific opcodes, or it can even be that the controller and device
* both support Quad IOs but the hardware prevents you from using it because
* only 2 IO lines are connected.
*
* This function checks whether a specific operation is supported.
*
* Return: true if @op is supported, false otherwise.
*/
bool spi_mem_supports_op(struct spi_mem *mem, const struct spi_mem_op *op)
{
if (spi_mem_check_op(op))
return false;
return spi_mem_internal_supports_op(mem, op);
}
/**
* spi_mem_exec_op() - Execute a memory operation
* @mem: the SPI memory
* @op: the memory operation to execute
*
* Executes a memory operation.
*
* This function first checks that @op is supported and then tries to execute
* it.
*
* Return: 0 in case of success, a negative error code otherwise.
*/
int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
{
unsigned int tmpbufsize, xferpos = 0, totalxferlen = 0;
struct spi_controller *ctlr = mem->spi->controller;
struct spi_transfer xfers[4] = { };
struct spi_message msg;
u8 *tmpbuf;
int ret;
ret = spi_mem_check_op(op);
if (ret)
return ret;
if (!spi_mem_internal_supports_op(mem, op))
return -ENOTSUPP;
if (ctlr->mem_ops) {
ret = spi_mem_access_start(mem);
if (ret)
return ret;
ret = ctlr->mem_ops->exec_op(mem, op);
spi_mem_access_end(mem);
/*
* Some controllers only optimize specific paths (typically the
* read path) and expect the core to use the regular SPI
* interface in other cases.
*/
if (!ret || ret != -ENOTSUPP)
return ret;
}
tmpbufsize = sizeof(op->cmd.opcode) + op->addr.nbytes +
op->dummy.nbytes;
/*
* Allocate a buffer to transmit the CMD, ADDR cycles with kmalloc() so
* we're guaranteed that this buffer is DMA-able, as required by the
* SPI layer.
*/
tmpbuf = kzalloc(tmpbufsize, GFP_KERNEL);
if (!tmpbuf)
return -ENOMEM;
spi_message_init(&msg);
tmpbuf[0] = op->cmd.opcode;
xfers[xferpos].tx_buf = tmpbuf;
xfers[xferpos].len = sizeof(op->cmd.opcode);
spi_message_add_tail(&xfers[xferpos], &msg);
xferpos++;
totalxferlen++;
if (op->addr.nbytes) {
int i;
for (i = 0; i < op->addr.nbytes; i++)
tmpbuf[i + 1] = op->addr.val >>
(8 * (op->addr.nbytes - i - 1));
xfers[xferpos].tx_buf = tmpbuf + 1;
xfers[xferpos].len = op->addr.nbytes;
spi_message_add_tail(&xfers[xferpos], &msg);
xferpos++;
totalxferlen += op->addr.nbytes;
}
/**
* spi_mem_exec_op() - Execute a memory operation
* @mem: the SPI memory
* @op: the memory operation to execute
*
* Executes a memory operation.
*
* This function first checks that @op is supported and then tries to execute
* it.
*
* Return: 0 in case of success, a negative error code otherwise.
*/
int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
{
unsigned int tmpbufsize, xferpos = 0, totalxferlen = 0;
struct spi_controller *ctlr = mem->spi->controller;
struct spi_transfer xfers[4] = { };
struct spi_message msg;
u8 *tmpbuf;
int ret;
ret = spi_mem_check_op(op);
if (ret)
return ret;
if (!spi_mem_internal_supports_op(mem, op))
return -ENOTSUPP;
if (ctlr->mem_ops) {
/*
* Flush the message queue before executing our SPI memory
* operation to prevent preemption of regular SPI transfers.
*/
spi_flush_queue(ctlr);
if (ctlr->auto_runtime_pm) {
ret = pm_runtime_get_sync(ctlr->dev.parent);
if (ret < 0) {
dev_err(&ctlr->dev,
"Failed to power device: %d\n",
ret);
return ret;
}
}
mutex_lock(&ctlr->bus_lock_mutex);
mutex_lock(&ctlr->io_mutex);
ret = ctlr->mem_ops->exec_op(mem, op);
mutex_unlock(&ctlr->io_mutex);
mutex_unlock(&ctlr->bus_lock_mutex);
if (ctlr->auto_runtime_pm)
pm_runtime_put(ctlr->dev.parent);
/*
* Some controllers only optimize specific paths (typically the
* read path) and expect the core to use the regular SPI
* interface in other cases.
*/
if (!ret || ret != -ENOTSUPP)
return ret;
}
tmpbufsize = sizeof(op->cmd.opcode) + op->addr.nbytes +
op->dummy.nbytes;
/*
* Allocate a buffer to transmit the CMD, ADDR cycles with kmalloc() so
* we're guaranteed that this buffer is DMA-able, as required by the
* SPI layer.
*/
tmpbuf = kzalloc(tmpbufsize, GFP_KERNEL | GFP_DMA);
if (!tmpbuf)
return -ENOMEM;
spi_message_init(&msg);
tmpbuf[0] = op->cmd.opcode;
xfers[xferpos].tx_buf = tmpbuf;
xfers[xferpos].len = sizeof(op->cmd.opcode);
xfers[xferpos].tx_nbits = op->cmd.buswidth;
spi_message_add_tail(&xfers[xferpos], &msg);
xferpos++;
totalxferlen++;
if (op->addr.nbytes) {
int i;
for (i = 0; i < op->addr.nbytes; i++)
tmpbuf[i + 1] = op->addr.val >>
(8 * (op->addr.nbytes - i - 1));
xfers[xferpos].tx_buf = tmpbuf + 1;
xfers[xferpos].len = op->addr.nbytes;
xfers[xferpos].tx_nbits = op->addr.buswidth;
spi_message_add_tail(&xfers[xferpos], &msg);
xferpos++;
totalxferlen += op->addr.nbytes;
}
