linux/drivers/spi/spi-mem.c
Chia-Lin Kao (AceLan) cff49d58f5
spi: Unify error codes by replacing -ENOTSUPP with -EOPNOTSUPP
This commit updates the SPI subsystem, particularly affecting "SPI MEM"
drivers and core parts, by replacing the -ENOTSUPP error code with
-EOPNOTSUPP.

The key motivations for this change are as follows:
1. The spi-nor driver currently uses EOPNOTSUPP, whereas calls to spi-mem
might return ENOTSUPP. This update aims to unify the error reporting
within the SPI subsystem for clarity and consistency.

2. The use of ENOTSUPP has been flagged by checkpatch as inappropriate,
mainly being reserved for NFS-related errors. To align with kernel coding
standards and recommendations, this change is being made.

3. By using EOPNOTSUPP, we provide more specific context to the error,
indicating that a particular operation is not supported. This helps
differentiate from the more generic ENOTSUPP error, allowing drivers to
better handle and respond to different error scenarios.

Risks and Considerations:
While this change is primarily intended as a code cleanup and error code
unification, there is a minor risk of breaking user-space applications
that rely on specific return codes for unsupported operations. However,
this risk is considered low, as such use-cases are unlikely to be common
or critical. Nevertheless, developers and users should be aware of this
change, especially if they have scripts or tools that specifically handle
SPI error codes.

This commit does not introduce any functional changes to the SPI subsystem
or the affected drivers.

Signed-off-by: "Chia-Lin Kao (AceLan)" <acelan.kao@canonical.com>
Acked-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20231129064311.272422-1-acelan.kao@canonical.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2023-11-30 12:12:39 +00:00

920 lines
24 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2018 Exceet Electronics GmbH
* Copyright (C) 2018 Bootlin
*
* Author: Boris Brezillon <boris.brezillon@bootlin.com>
*/
#include <linux/dmaengine.h>
#include <linux/iopoll.h>
#include <linux/pm_runtime.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi-mem.h>
#include <linux/sched/task_stack.h>
#include "internals.h"
#define SPI_MEM_MAX_BUSWIDTH 8
/**
* spi_controller_dma_map_mem_op_data() - DMA-map the buffer attached to a
* memory operation
* @ctlr: the SPI controller requesting this dma_map()
* @op: the memory operation containing the buffer to map
* @sgt: a pointer to a non-initialized sg_table that will be filled by this
* function
*
* Some controllers might want to do DMA on the data buffer embedded in @op.
* This helper prepares everything for you and provides a ready-to-use
* sg_table. This function is not intended to be called from spi drivers.
* Only SPI controller drivers should use it.
* Note that the caller must ensure the memory region pointed by
* op->data.buf.{in,out} is DMA-able before calling this function.
*
* Return: 0 in case of success, a negative error code otherwise.
*/
int spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
const struct spi_mem_op *op,
struct sg_table *sgt)
{
struct device *dmadev;
if (!op->data.nbytes)
return -EINVAL;
if (op->data.dir == SPI_MEM_DATA_OUT && ctlr->dma_tx)
dmadev = ctlr->dma_tx->device->dev;
else if (op->data.dir == SPI_MEM_DATA_IN && ctlr->dma_rx)
dmadev = ctlr->dma_rx->device->dev;
else
dmadev = ctlr->dev.parent;
if (!dmadev)
return -EINVAL;
return spi_map_buf(ctlr, dmadev, sgt, op->data.buf.in, op->data.nbytes,
op->data.dir == SPI_MEM_DATA_IN ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
EXPORT_SYMBOL_GPL(spi_controller_dma_map_mem_op_data);
/**
* spi_controller_dma_unmap_mem_op_data() - DMA-unmap the buffer attached to a
* memory operation
* @ctlr: the SPI controller requesting this dma_unmap()
* @op: the memory operation containing the buffer to unmap
* @sgt: a pointer to an sg_table previously initialized by
* spi_controller_dma_map_mem_op_data()
*
* Some controllers might want to do DMA on the data buffer embedded in @op.
* This helper prepares things so that the CPU can access the
* op->data.buf.{in,out} buffer again.
*
* This function is not intended to be called from SPI drivers. Only SPI
* controller drivers should use it.
*
* This function should be called after the DMA operation has finished and is
* only valid if the previous spi_controller_dma_map_mem_op_data() call
* returned 0.
*
* Return: 0 in case of success, a negative error code otherwise.
*/
void spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
const struct spi_mem_op *op,
struct sg_table *sgt)
{
struct device *dmadev;
if (!op->data.nbytes)
return;
if (op->data.dir == SPI_MEM_DATA_OUT && ctlr->dma_tx)
dmadev = ctlr->dma_tx->device->dev;
else if (op->data.dir == SPI_MEM_DATA_IN && ctlr->dma_rx)
dmadev = ctlr->dma_rx->device->dev;
else
dmadev = ctlr->dev.parent;
spi_unmap_buf(ctlr, dmadev, sgt,
op->data.dir == SPI_MEM_DATA_IN ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
EXPORT_SYMBOL_GPL(spi_controller_dma_unmap_mem_op_data);
static int spi_check_buswidth_req(struct spi_mem *mem, u8 buswidth, bool tx)
{
u32 mode = mem->spi->mode;
switch (buswidth) {
case 1:
return 0;
case 2:
if ((tx &&
(mode & (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL))) ||
(!tx &&
(mode & (SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL))))
return 0;
break;
case 4:
if ((tx && (mode & (SPI_TX_QUAD | SPI_TX_OCTAL))) ||
(!tx && (mode & (SPI_RX_QUAD | SPI_RX_OCTAL))))
return 0;
break;
case 8:
if ((tx && (mode & SPI_TX_OCTAL)) ||
(!tx && (mode & SPI_RX_OCTAL)))
return 0;
break;
default:
break;
}
return -ENOTSUPP;
}
static bool spi_mem_check_buswidth(struct spi_mem *mem,
const struct spi_mem_op *op)
{
if (spi_check_buswidth_req(mem, op->cmd.buswidth, true))
return false;
if (op->addr.nbytes &&
spi_check_buswidth_req(mem, op->addr.buswidth, true))
return false;
if (op->dummy.nbytes &&
spi_check_buswidth_req(mem, op->dummy.buswidth, true))
return false;
if (op->data.dir != SPI_MEM_NO_DATA &&
spi_check_buswidth_req(mem, op->data.buswidth,
op->data.dir == SPI_MEM_DATA_OUT))
return false;
return true;
}
bool spi_mem_default_supports_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
struct spi_controller *ctlr = mem->spi->controller;
bool op_is_dtr =
op->cmd.dtr || op->addr.dtr || op->dummy.dtr || op->data.dtr;
if (op_is_dtr) {
if (!spi_mem_controller_is_capable(ctlr, dtr))
return false;
if (op->cmd.nbytes != 2)
return false;
} else {
if (op->cmd.nbytes != 1)
return false;
}
if (op->data.ecc) {
if (!spi_mem_controller_is_capable(ctlr, ecc))
return false;
}
return spi_mem_check_buswidth(mem, op);
}
EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);
static bool spi_mem_buswidth_is_valid(u8 buswidth)
{
if (hweight8(buswidth) > 1 || buswidth > SPI_MEM_MAX_BUSWIDTH)
return false;
return true;
}
static int spi_mem_check_op(const struct spi_mem_op *op)
{
if (!op->cmd.buswidth || !op->cmd.nbytes)
return -EINVAL;
if ((op->addr.nbytes && !op->addr.buswidth) ||
(op->dummy.nbytes && !op->dummy.buswidth) ||
(op->data.nbytes && !op->data.buswidth))
return -EINVAL;
if (!spi_mem_buswidth_is_valid(op->cmd.buswidth) ||
!spi_mem_buswidth_is_valid(op->addr.buswidth) ||
!spi_mem_buswidth_is_valid(op->dummy.buswidth) ||
!spi_mem_buswidth_is_valid(op->data.buswidth))
return -EINVAL;
/* Buffers must be DMA-able. */
if (WARN_ON_ONCE(op->data.dir == SPI_MEM_DATA_IN &&
object_is_on_stack(op->data.buf.in)))
return -EINVAL;
if (WARN_ON_ONCE(op->data.dir == SPI_MEM_DATA_OUT &&
object_is_on_stack(op->data.buf.out)))
return -EINVAL;
return 0;
}
static bool spi_mem_internal_supports_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
struct spi_controller *ctlr = mem->spi->controller;
if (ctlr->mem_ops && ctlr->mem_ops->supports_op)
return ctlr->mem_ops->supports_op(mem, op);
return spi_mem_default_supports_op(mem, op);
}
/**
* 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);
}
EXPORT_SYMBOL_GPL(spi_mem_supports_op);
static int spi_mem_access_start(struct spi_mem *mem)
{
struct spi_controller *ctlr = mem->spi->controller;
/*
* 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) {
int ret;
ret = pm_runtime_resume_and_get(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);
return 0;
}
static void spi_mem_access_end(struct spi_mem *mem)
{
struct spi_controller *ctlr = mem->spi->controller;
mutex_unlock(&ctlr->io_mutex);
mutex_unlock(&ctlr->bus_lock_mutex);
if (ctlr->auto_runtime_pm)
pm_runtime_put(ctlr->dev.parent);
}
/**
* 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 -EOPNOTSUPP;
if (ctlr->mem_ops && ctlr->mem_ops->exec_op && !spi_get_csgpiod(mem->spi, 0)) {
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 || ret != -EOPNOTSUPP)
return ret;
}
tmpbufsize = op->cmd.nbytes + 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 = op->cmd.nbytes;
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;
}
if (op->dummy.nbytes) {
memset(tmpbuf + op->addr.nbytes + 1, 0xff, op->dummy.nbytes);
xfers[xferpos].tx_buf = tmpbuf + op->addr.nbytes + 1;
xfers[xferpos].len = op->dummy.nbytes;
xfers[xferpos].tx_nbits = op->dummy.buswidth;
xfers[xferpos].dummy_data = 1;
spi_message_add_tail(&xfers[xferpos], &msg);
xferpos++;
totalxferlen += op->dummy.nbytes;
}
if (op->data.nbytes) {
if (op->data.dir == SPI_MEM_DATA_IN) {
xfers[xferpos].rx_buf = op->data.buf.in;
xfers[xferpos].rx_nbits = op->data.buswidth;
} else {
xfers[xferpos].tx_buf = op->data.buf.out;
xfers[xferpos].tx_nbits = op->data.buswidth;
}
xfers[xferpos].len = op->data.nbytes;
spi_message_add_tail(&xfers[xferpos], &msg);
xferpos++;
totalxferlen += op->data.nbytes;
}
ret = spi_sync(mem->spi, &msg);
kfree(tmpbuf);
if (ret)
return ret;
if (msg.actual_length != totalxferlen)
return -EIO;
return 0;
}
EXPORT_SYMBOL_GPL(spi_mem_exec_op);
/**
* spi_mem_get_name() - Return the SPI mem device name to be used by the
* upper layer if necessary
* @mem: the SPI memory
*
* This function allows SPI mem users to retrieve the SPI mem device name.
* It is useful if the upper layer needs to expose a custom name for
* compatibility reasons.
*
* Return: a string containing the name of the memory device to be used
* by the SPI mem user
*/
const char *spi_mem_get_name(struct spi_mem *mem)
{
return mem->name;
}
EXPORT_SYMBOL_GPL(spi_mem_get_name);
/**
* spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to
* match controller limitations
* @mem: the SPI memory
* @op: the operation to adjust
*
* Some controllers have FIFO limitations and must split a data transfer
* operation into multiple ones, others require a specific alignment for
* optimized accesses. This function allows SPI mem drivers to split a single
* operation into multiple sub-operations when required.
*
* Return: a negative error code if the controller can't properly adjust @op,
* 0 otherwise. Note that @op->data.nbytes will be updated if @op
* can't be handled in a single step.
*/
int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
{
struct spi_controller *ctlr = mem->spi->controller;
size_t len;
if (ctlr->mem_ops && ctlr->mem_ops->adjust_op_size)
return ctlr->mem_ops->adjust_op_size(mem, op);
if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) {
len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
if (len > spi_max_transfer_size(mem->spi))
return -EINVAL;
op->data.nbytes = min3((size_t)op->data.nbytes,
spi_max_transfer_size(mem->spi),
spi_max_message_size(mem->spi) -
len);
if (!op->data.nbytes)
return -EINVAL;
}
return 0;
}
EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size);
static ssize_t spi_mem_no_dirmap_read(struct spi_mem_dirmap_desc *desc,
u64 offs, size_t len, void *buf)
{
struct spi_mem_op op = desc->info.op_tmpl;
int ret;
op.addr.val = desc->info.offset + offs;
op.data.buf.in = buf;
op.data.nbytes = len;
ret = spi_mem_adjust_op_size(desc->mem, &op);
if (ret)
return ret;
ret = spi_mem_exec_op(desc->mem, &op);
if (ret)
return ret;
return op.data.nbytes;
}
static ssize_t spi_mem_no_dirmap_write(struct spi_mem_dirmap_desc *desc,
u64 offs, size_t len, const void *buf)
{
struct spi_mem_op op = desc->info.op_tmpl;
int ret;
op.addr.val = desc->info.offset + offs;
op.data.buf.out = buf;
op.data.nbytes = len;
ret = spi_mem_adjust_op_size(desc->mem, &op);
if (ret)
return ret;
ret = spi_mem_exec_op(desc->mem, &op);
if (ret)
return ret;
return op.data.nbytes;
}
/**
* spi_mem_dirmap_create() - Create a direct mapping descriptor
* @mem: SPI mem device this direct mapping should be created for
* @info: direct mapping information
*
* This function is creating a direct mapping descriptor which can then be used
* to access the memory using spi_mem_dirmap_read() or spi_mem_dirmap_write().
* If the SPI controller driver does not support direct mapping, this function
* falls back to an implementation using spi_mem_exec_op(), so that the caller
* doesn't have to bother implementing a fallback on his own.
*
* Return: a valid pointer in case of success, and ERR_PTR() otherwise.
*/
struct spi_mem_dirmap_desc *
spi_mem_dirmap_create(struct spi_mem *mem,
const struct spi_mem_dirmap_info *info)
{
struct spi_controller *ctlr = mem->spi->controller;
struct spi_mem_dirmap_desc *desc;
int ret = -ENOTSUPP;
/* Make sure the number of address cycles is between 1 and 8 bytes. */
if (!info->op_tmpl.addr.nbytes || info->op_tmpl.addr.nbytes > 8)
return ERR_PTR(-EINVAL);
/* data.dir should either be SPI_MEM_DATA_IN or SPI_MEM_DATA_OUT. */
if (info->op_tmpl.data.dir == SPI_MEM_NO_DATA)
return ERR_PTR(-EINVAL);
desc = kzalloc(sizeof(*desc), GFP_KERNEL);
if (!desc)
return ERR_PTR(-ENOMEM);
desc->mem = mem;
desc->info = *info;
if (ctlr->mem_ops && ctlr->mem_ops->dirmap_create)
ret = ctlr->mem_ops->dirmap_create(desc);
if (ret) {
desc->nodirmap = true;
if (!spi_mem_supports_op(desc->mem, &desc->info.op_tmpl))
ret = -EOPNOTSUPP;
else
ret = 0;
}
if (ret) {
kfree(desc);
return ERR_PTR(ret);
}
return desc;
}
EXPORT_SYMBOL_GPL(spi_mem_dirmap_create);
/**
* spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor
* @desc: the direct mapping descriptor to destroy
*
* This function destroys a direct mapping descriptor previously created by
* spi_mem_dirmap_create().
*/
void spi_mem_dirmap_destroy(struct spi_mem_dirmap_desc *desc)
{
struct spi_controller *ctlr = desc->mem->spi->controller;
if (!desc->nodirmap && ctlr->mem_ops && ctlr->mem_ops->dirmap_destroy)
ctlr->mem_ops->dirmap_destroy(desc);
kfree(desc);
}
EXPORT_SYMBOL_GPL(spi_mem_dirmap_destroy);
static void devm_spi_mem_dirmap_release(struct device *dev, void *res)
{
struct spi_mem_dirmap_desc *desc = *(struct spi_mem_dirmap_desc **)res;
spi_mem_dirmap_destroy(desc);
}
/**
* devm_spi_mem_dirmap_create() - Create a direct mapping descriptor and attach
* it to a device
* @dev: device the dirmap desc will be attached to
* @mem: SPI mem device this direct mapping should be created for
* @info: direct mapping information
*
* devm_ variant of the spi_mem_dirmap_create() function. See
* spi_mem_dirmap_create() for more details.
*
* Return: a valid pointer in case of success, and ERR_PTR() otherwise.
*/
struct spi_mem_dirmap_desc *
devm_spi_mem_dirmap_create(struct device *dev, struct spi_mem *mem,
const struct spi_mem_dirmap_info *info)
{
struct spi_mem_dirmap_desc **ptr, *desc;
ptr = devres_alloc(devm_spi_mem_dirmap_release, sizeof(*ptr),
GFP_KERNEL);
if (!ptr)
return ERR_PTR(-ENOMEM);
desc = spi_mem_dirmap_create(mem, info);
if (IS_ERR(desc)) {
devres_free(ptr);
} else {
*ptr = desc;
devres_add(dev, ptr);
}
return desc;
}
EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_create);
static int devm_spi_mem_dirmap_match(struct device *dev, void *res, void *data)
{
struct spi_mem_dirmap_desc **ptr = res;
if (WARN_ON(!ptr || !*ptr))
return 0;
return *ptr == data;
}
/**
* devm_spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor attached
* to a device
* @dev: device the dirmap desc is attached to
* @desc: the direct mapping descriptor to destroy
*
* devm_ variant of the spi_mem_dirmap_destroy() function. See
* spi_mem_dirmap_destroy() for more details.
*/
void devm_spi_mem_dirmap_destroy(struct device *dev,
struct spi_mem_dirmap_desc *desc)
{
devres_release(dev, devm_spi_mem_dirmap_release,
devm_spi_mem_dirmap_match, desc);
}
EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_destroy);
/**
* spi_mem_dirmap_read() - Read data through a direct mapping
* @desc: direct mapping descriptor
* @offs: offset to start reading from. Note that this is not an absolute
* offset, but the offset within the direct mapping which already has
* its own offset
* @len: length in bytes
* @buf: destination buffer. This buffer must be DMA-able
*
* This function reads data from a memory device using a direct mapping
* previously instantiated with spi_mem_dirmap_create().
*
* Return: the amount of data read from the memory device or a negative error
* code. Note that the returned size might be smaller than @len, and the caller
* is responsible for calling spi_mem_dirmap_read() again when that happens.
*/
ssize_t spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
u64 offs, size_t len, void *buf)
{
struct spi_controller *ctlr = desc->mem->spi->controller;
ssize_t ret;
if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_IN)
return -EINVAL;
if (!len)
return 0;
if (desc->nodirmap) {
ret = spi_mem_no_dirmap_read(desc, offs, len, buf);
} else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_read) {
ret = spi_mem_access_start(desc->mem);
if (ret)
return ret;
ret = ctlr->mem_ops->dirmap_read(desc, offs, len, buf);
spi_mem_access_end(desc->mem);
} else {
ret = -ENOTSUPP;
}
return ret;
}
EXPORT_SYMBOL_GPL(spi_mem_dirmap_read);
/**
* spi_mem_dirmap_write() - Write data through a direct mapping
* @desc: direct mapping descriptor
* @offs: offset to start writing from. Note that this is not an absolute
* offset, but the offset within the direct mapping which already has
* its own offset
* @len: length in bytes
* @buf: source buffer. This buffer must be DMA-able
*
* This function writes data to a memory device using a direct mapping
* previously instantiated with spi_mem_dirmap_create().
*
* Return: the amount of data written to the memory device or a negative error
* code. Note that the returned size might be smaller than @len, and the caller
* is responsible for calling spi_mem_dirmap_write() again when that happens.
*/
ssize_t spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
u64 offs, size_t len, const void *buf)
{
struct spi_controller *ctlr = desc->mem->spi->controller;
ssize_t ret;
if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_OUT)
return -EINVAL;
if (!len)
return 0;
if (desc->nodirmap) {
ret = spi_mem_no_dirmap_write(desc, offs, len, buf);
} else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_write) {
ret = spi_mem_access_start(desc->mem);
if (ret)
return ret;
ret = ctlr->mem_ops->dirmap_write(desc, offs, len, buf);
spi_mem_access_end(desc->mem);
} else {
ret = -ENOTSUPP;
}
return ret;
}
EXPORT_SYMBOL_GPL(spi_mem_dirmap_write);
static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv)
{
return container_of(drv, struct spi_mem_driver, spidrv.driver);
}
static int spi_mem_read_status(struct spi_mem *mem,
const struct spi_mem_op *op,
u16 *status)
{
const u8 *bytes = (u8 *)op->data.buf.in;
int ret;
ret = spi_mem_exec_op(mem, op);
if (ret)
return ret;
if (op->data.nbytes > 1)
*status = ((u16)bytes[0] << 8) | bytes[1];
else
*status = bytes[0];
return 0;
}
/**
* spi_mem_poll_status() - Poll memory device status
* @mem: SPI memory device
* @op: the memory operation to execute
* @mask: status bitmask to ckeck
* @match: (status & mask) expected value
* @initial_delay_us: delay in us before starting to poll
* @polling_delay_us: time to sleep between reads in us
* @timeout_ms: timeout in milliseconds
*
* This function polls a status register and returns when
* (status & mask) == match or when the timeout has expired.
*
* Return: 0 in case of success, -ETIMEDOUT in case of error,
* -EOPNOTSUPP if not supported.
*/
int spi_mem_poll_status(struct spi_mem *mem,
const struct spi_mem_op *op,
u16 mask, u16 match,
unsigned long initial_delay_us,
unsigned long polling_delay_us,
u16 timeout_ms)
{
struct spi_controller *ctlr = mem->spi->controller;
int ret = -EOPNOTSUPP;
int read_status_ret;
u16 status;
if (op->data.nbytes < 1 || op->data.nbytes > 2 ||
op->data.dir != SPI_MEM_DATA_IN)
return -EINVAL;
if (ctlr->mem_ops && ctlr->mem_ops->poll_status && !spi_get_csgpiod(mem->spi, 0)) {
ret = spi_mem_access_start(mem);
if (ret)
return ret;
ret = ctlr->mem_ops->poll_status(mem, op, mask, match,
initial_delay_us, polling_delay_us,
timeout_ms);
spi_mem_access_end(mem);
}
if (ret == -EOPNOTSUPP) {
if (!spi_mem_supports_op(mem, op))
return ret;
if (initial_delay_us < 10)
udelay(initial_delay_us);
else
usleep_range((initial_delay_us >> 2) + 1,
initial_delay_us);
ret = read_poll_timeout(spi_mem_read_status, read_status_ret,
(read_status_ret || ((status) & mask) == match),
polling_delay_us, timeout_ms * 1000, false, mem,
op, &status);
if (read_status_ret)
return read_status_ret;
}
return ret;
}
EXPORT_SYMBOL_GPL(spi_mem_poll_status);
static int spi_mem_probe(struct spi_device *spi)
{
struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
struct spi_controller *ctlr = spi->controller;
struct spi_mem *mem;
mem = devm_kzalloc(&spi->dev, sizeof(*mem), GFP_KERNEL);
if (!mem)
return -ENOMEM;
mem->spi = spi;
if (ctlr->mem_ops && ctlr->mem_ops->get_name)
mem->name = ctlr->mem_ops->get_name(mem);
else
mem->name = dev_name(&spi->dev);
if (IS_ERR_OR_NULL(mem->name))
return PTR_ERR_OR_ZERO(mem->name);
spi_set_drvdata(spi, mem);
return memdrv->probe(mem);
}
static void spi_mem_remove(struct spi_device *spi)
{
struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
struct spi_mem *mem = spi_get_drvdata(spi);
if (memdrv->remove)
memdrv->remove(mem);
}
static void spi_mem_shutdown(struct spi_device *spi)
{
struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
struct spi_mem *mem = spi_get_drvdata(spi);
if (memdrv->shutdown)
memdrv->shutdown(mem);
}
/**
* spi_mem_driver_register_with_owner() - Register a SPI memory driver
* @memdrv: the SPI memory driver to register
* @owner: the owner of this driver
*
* Registers a SPI memory driver.
*
* Return: 0 in case of success, a negative error core otherwise.
*/
int spi_mem_driver_register_with_owner(struct spi_mem_driver *memdrv,
struct module *owner)
{
memdrv->spidrv.probe = spi_mem_probe;
memdrv->spidrv.remove = spi_mem_remove;
memdrv->spidrv.shutdown = spi_mem_shutdown;
return __spi_register_driver(owner, &memdrv->spidrv);
}
EXPORT_SYMBOL_GPL(spi_mem_driver_register_with_owner);
/**
* spi_mem_driver_unregister() - Unregister a SPI memory driver
* @memdrv: the SPI memory driver to unregister
*
* Unregisters a SPI memory driver.
*/
void spi_mem_driver_unregister(struct spi_mem_driver *memdrv)
{
spi_unregister_driver(&memdrv->spidrv);
}
EXPORT_SYMBOL_GPL(spi_mem_driver_unregister);