diff options
Diffstat (limited to 'drivers/spi/spi-mem.c')
| -rw-r--r-- | drivers/spi/spi-mem.c | 919 |
1 files changed, 919 insertions, 0 deletions
diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c new file mode 100644 index 000000000..0c79193d9 --- /dev/null +++ b/drivers/spi/spi-mem.c @@ -0,0 +1,919 @@ +// 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 -ENOTSUPP; + + if (ctlr->mem_ops && !mem->spi->cs_gpiod) { + 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 = 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 = -ENOTSUPP; + 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 && !mem->spi->cs_gpiod) { + 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); |