diff options
| -rw-r--r-- | drivers/mtd/spi-nor/spi-nor.c | 38 | ||||
| -rw-r--r-- | drivers/spi/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/spi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/spi/spi-mem.c | 524 | ||||
| -rw-r--r-- | drivers/spi/spi.c | 39 | ||||
| -rw-r--r-- | include/linux/spi/spi-mem.h | 307 | ||||
| -rw-r--r-- | include/spi/spi.h | 55 |
7 files changed, 948 insertions, 23 deletions
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index 85b55c6982..851ac1c33e 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -784,7 +784,8 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf) { struct spi_nor *nor = mtd_to_spi_nor(mtd); - u32 page_offset, page_size, i; + size_t page_offset, page_remain, i; + size_t retval; int ret; dev_dbg(nor->dev, "to 0x%08x, len %zd\n", (u32)to, len); @@ -793,32 +794,23 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len, if (ret) return ret; - write_enable(nor); - - page_offset = to & (nor->page_size - 1); - - /* do all the bytes fit onto one page? */ - if (page_offset + len <= nor->page_size) { - nor->write(nor, to, len, retlen, buf); - } else { - /* the size of data remaining on the first page */ - page_size = nor->page_size - page_offset; - nor->write(nor, to, page_size, retlen, buf); + for (i = 0; i < len; ) { + ssize_t written; - /* write everything in nor->page_size chunks */ - for (i = page_size; i < len; i += page_size) { - page_size = len - i; - if (page_size > nor->page_size) - page_size = nor->page_size; + page_offset = (to + i) & (nor->page_size - 1); + page_remain = min_t(size_t, nor->page_size - page_offset, + len - i); - ret = spi_nor_wait_till_ready(nor); - if (ret) - goto write_err; + write_enable(nor); + nor->write(nor, to + i, page_remain, &retval, buf + i); + written = retval; - write_enable(nor); + ret = spi_nor_wait_till_ready(nor); + if (ret) + goto write_err; - nor->write(nor, to + i, page_size, retlen, buf + i); - } + *retlen += written; + i += written; } ret = spi_nor_wait_till_ready(nor); diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index fed628c589..650292541f 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -6,6 +6,13 @@ config SPI if SPI +config SPI_MEM + bool "SPI memory extension" + help + Enable this option if you want to enable the SPI memory extension. + This extension is meant to simplify interaction with SPI memories + by providing a high-level interface to send memory-like commands. + config DRIVER_SPI_ALTERA bool "Altera SPI Master driver" depends on NIOS2 diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 2329cbfb8d..841d67d326 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -1,4 +1,5 @@ obj-$(CONFIG_SPI) += spi.o +obj-$(CONFIG_SPI_MEM) += spi-mem.o obj-$(CONFIG_DRIVER_SPI_ATH79) += ath79_spi.o obj-$(CONFIG_DRIVER_SPI_GPIO) += gpio_spi.o obj-$(CONFIG_DRIVER_SPI_IMX) += imx_spi.o diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c new file mode 100644 index 0000000000..b438ed3dcc --- /dev/null +++ b/drivers/spi/spi-mem.c @@ -0,0 +1,524 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2018 Exceet Electronics GmbH + * Copyright (C) 2018 Bootlin + * + * Author: Boris Brezillon <boris.brezillon@bootlin.com> + */ +#include <common.h> +#include <module.h> +#include <linux/kernel.h> +#include <linux/spi/spi-mem.h> +#include <spi/spi.h> + +#define SPI_MEM_MAX_BUSWIDTH 8 + +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))) || + (!tx && (mode & (SPI_RX_DUAL | SPI_RX_QUAD)))) + return 0; + + break; + + case 4: + if ((tx && (mode & SPI_TX_QUAD)) || + (!tx && (mode & SPI_RX_QUAD))) + 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_default_supports_op(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; +} +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) + 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; + + 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) +{ + return 0; +} + +static void spi_mem_access_end(struct spi_mem *mem) +{ + return; +} + +/** + * 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; + } + + 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; + 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; + else + xfers[xferpos].tx_buf = op->data.buf.out; + + 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; + + len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes; + + 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) { + 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 + * fallback 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 + * @info: direct mapping information + * + * 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); +} +EXPORT_SYMBOL_GPL(spi_mem_dirmap_destroy); + +/** + * spi_mem_dirmap_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_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); diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 7756304f19..d9311d4af5 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -19,6 +19,7 @@ */ #include <common.h> +#include <linux/spi/spi-mem.h> #include <spi/spi.h> #include <xfuncs.h> #include <malloc.h> @@ -58,6 +59,7 @@ struct spi_device *spi_new_device(struct spi_controller *ctrl, struct spi_board_info *chip) { struct spi_device *proxy; + struct spi_mem *mem; int status; /* Chipselects are numbered 0..max; validate. */ @@ -84,6 +86,15 @@ struct spi_device *spi_new_device(struct spi_controller *ctrl, proxy->dev.parent = ctrl->dev; proxy->master = proxy->controller = ctrl; + mem = xzalloc(sizeof *mem); + mem->spi = proxy; + + if (ctrl->mem_ops && ctrl->mem_ops->get_name) + mem->name = ctrl->mem_ops->get_name(mem); + else + mem->name = dev_name(&proxy->dev); + proxy->mem = mem; + /* drivers may modify this initial i/o setup */ status = ctrl->setup(proxy); if (status < 0) { @@ -194,6 +205,26 @@ static void scan_boardinfo(struct spi_controller *ctrl) static LIST_HEAD(spi_controller_list); +static int spi_controller_check_ops(struct spi_controller *ctlr) +{ + /* + * The controller may implement only the high-level SPI-memory like + * operations if it does not support regular SPI transfers, and this is + * valid use case. + * If ->mem_ops is NULL, we request that at least one of the + * ->transfer_xxx() method be implemented. + */ + if (ctlr->mem_ops) { + if (!ctlr->mem_ops->exec_op) + return -EINVAL; + } else if (!ctlr->transfer) { + return -EINVAL; + } + + return 0; +} + + /** * spi_register_ctrl - register SPI ctrl controller * @ctrl: initialized ctrl, originally from spi_alloc_ctrl() @@ -221,6 +252,14 @@ int spi_register_controller(struct spi_controller *ctrl) debug("%s: %s:%d\n", __func__, ctrl->dev->name, ctrl->dev->id); + /* + * Make sure all necessary hooks are implemented before registering + * the SPI controller. + */ + status = spi_controller_check_ops(ctrl); + if (status) + return status; + /* even if it's just one always-selected device, there must * be at least one chipselect */ diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h new file mode 100644 index 0000000000..f65104d2d1 --- /dev/null +++ b/include/linux/spi/spi-mem.h @@ -0,0 +1,307 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (C) 2018 Exceet Electronics GmbH + * Copyright (C) 2018 Bootlin + * + * Author: + * Peter Pan <peterpandong@micron.com> + * Boris Brezillon <boris.brezillon@bootlin.com> + */ + +#ifndef __LINUX_SPI_MEM_H +#define __LINUX_SPI_MEM_H + +#include <spi/spi.h> + +#define SPI_MEM_OP_CMD(__opcode, __buswidth) \ + { \ + .buswidth = __buswidth, \ + .opcode = __opcode, \ + } + +#define SPI_MEM_OP_ADDR(__nbytes, __val, __buswidth) \ + { \ + .nbytes = __nbytes, \ + .val = __val, \ + .buswidth = __buswidth, \ + } + +#define SPI_MEM_OP_NO_ADDR { } + +#define SPI_MEM_OP_DUMMY(__nbytes, __buswidth) \ + { \ + .nbytes = __nbytes, \ + .buswidth = __buswidth, \ + } + +#define SPI_MEM_OP_NO_DUMMY { } + +#define SPI_MEM_OP_DATA_IN(__nbytes, __buf, __buswidth) \ + { \ + .dir = SPI_MEM_DATA_IN, \ + .nbytes = __nbytes, \ + .buf.in = __buf, \ + .buswidth = __buswidth, \ + } + +#define SPI_MEM_OP_DATA_OUT(__nbytes, __buf, __buswidth) \ + { \ + .dir = SPI_MEM_DATA_OUT, \ + .nbytes = __nbytes, \ + .buf.out = __buf, \ + .buswidth = __buswidth, \ + } + +#define SPI_MEM_OP_NO_DATA { } + +/** + * enum spi_mem_data_dir - describes the direction of a SPI memory data + * transfer from the controller perspective + * @SPI_MEM_NO_DATA: no data transferred + * @SPI_MEM_DATA_IN: data coming from the SPI memory + * @SPI_MEM_DATA_OUT: data sent to the SPI memory + */ +enum spi_mem_data_dir { + SPI_MEM_NO_DATA, + SPI_MEM_DATA_IN, + SPI_MEM_DATA_OUT, +}; + +/** + * struct spi_mem_op - describes a SPI memory operation + * @cmd.buswidth: number of IO lines used to transmit the command + * @cmd.opcode: operation opcode + * @addr.nbytes: number of address bytes to send. Can be zero if the operation + * does not need to send an address + * @addr.buswidth: number of IO lines used to transmit the address cycles + * @addr.val: address value. This value is always sent MSB first on the bus. + * Note that only @addr.nbytes are taken into account in this + * address value, so users should make sure the value fits in the + * assigned number of bytes. + * @dummy.nbytes: number of dummy bytes to send after an opcode or address. Can + * be zero if the operation does not require dummy bytes + * @dummy.buswidth: number of IO lanes used to transmit the dummy bytes + * @data.buswidth: number of IO lanes used to send/receive the data + * @data.dir: direction of the transfer + * @data.nbytes: number of data bytes to send/receive. Can be zero if the + * operation does not involve transferring data + * @data.buf.in: input buffer (must be DMA-able) + * @data.buf.out: output buffer (must be DMA-able) + */ +struct spi_mem_op { + struct { + u8 buswidth; + u8 opcode; + } cmd; + + struct { + u8 nbytes; + u8 buswidth; + u64 val; + } addr; + + struct { + u8 nbytes; + u8 buswidth; + } dummy; + + struct { + u8 buswidth; + enum spi_mem_data_dir dir; + unsigned int nbytes; + union { + void *in; + const void *out; + } buf; + } data; +}; + +#define SPI_MEM_OP(__cmd, __addr, __dummy, __data) \ + { \ + .cmd = __cmd, \ + .addr = __addr, \ + .dummy = __dummy, \ + .data = __data, \ + } + +/** + * struct spi_mem_dirmap_info - Direct mapping information + * @op_tmpl: operation template that should be used by the direct mapping when + * the memory device is accessed + * @offset: absolute offset this direct mapping is pointing to + * @length: length in byte of this direct mapping + * + * These information are used by the controller specific implementation to know + * the portion of memory that is directly mapped and the spi_mem_op that should + * be used to access the device. + * A direct mapping is only valid for one direction (read or write) and this + * direction is directly encoded in the ->op_tmpl.data.dir field. + */ +struct spi_mem_dirmap_info { + struct spi_mem_op op_tmpl; + u64 offset; + u64 length; +}; + +/** + * struct spi_mem_dirmap_desc - Direct mapping descriptor + * @mem: the SPI memory device this direct mapping is attached to + * @info: information passed at direct mapping creation time + * @nodirmap: set to 1 if the SPI controller does not implement + * ->mem_ops->dirmap_create() or when this function returned an + * error. If @nodirmap is true, all spi_mem_dirmap_{read,write}() + * calls will use spi_mem_exec_op() to access the memory. This is a + * degraded mode that allows spi_mem drivers to use the same code + * no matter whether the controller supports direct mapping or not + * @priv: field pointing to controller specific data + * + * Common part of a direct mapping descriptor. This object is created by + * spi_mem_dirmap_create() and controller implementation of ->create_dirmap() + * can create/attach direct mapping resources to the descriptor in the ->priv + * field. + */ +struct spi_mem_dirmap_desc { + struct spi_mem *mem; + struct spi_mem_dirmap_info info; + unsigned int nodirmap; + void *priv; +}; + +/** + * struct spi_mem - describes a SPI memory device + * @spi: the underlying SPI device + * @drvpriv: spi_mem_driver private data + * @name: name of the SPI memory device + * + * Extra information that describe the SPI memory device and may be needed by + * the controller to properly handle this device should be placed here. + * + * One example would be the device size since some controller expose their SPI + * mem devices through a io-mapped region. + */ +struct spi_mem { + struct spi_device *spi; + void *drvpriv; + const char *name; +}; + +/** + * struct spi_mem_set_drvdata() - attach driver private data to a SPI mem + * device + * @mem: memory device + * @data: data to attach to the memory device + */ +static inline void spi_mem_set_drvdata(struct spi_mem *mem, void *data) +{ + mem->drvpriv = data; +} + +/** + * struct spi_mem_get_drvdata() - get driver private data attached to a SPI mem + * device + * @mem: memory device + * + * Return: the data attached to the mem device. + */ +static inline void *spi_mem_get_drvdata(struct spi_mem *mem) +{ + return mem->drvpriv; +} + +/** + * struct spi_controller_mem_ops - SPI memory operations + * @adjust_op_size: shrink the data xfer of an operation to match controller's + * limitations (can be alignment of max RX/TX size + * limitations) + * @supports_op: check if an operation is supported by the controller + * @exec_op: execute a SPI memory operation + * @get_name: get a custom name for the SPI mem device from the controller. + * This might be needed if the controller driver has been ported + * to use the SPI mem layer and a custom name is used to keep + * mtdparts compatible. + * Note that if the implementation of this function allocates memory + * dynamically, then it should do so with devm_xxx(), as we don't + * have a ->free_name() function. + * @dirmap_create: create a direct mapping descriptor that can later be used to + * access the memory device. This method is optional + * @dirmap_destroy: destroy a memory descriptor previous created by + * ->dirmap_create() + * @dirmap_read: read data from the memory device using the direct mapping + * created by ->dirmap_create(). The function can return less + * data than requested (for example when the request is crossing + * the currently mapped area), and the caller of + * spi_mem_dirmap_read() is responsible for calling it again in + * this case. + * @dirmap_write: write data to the memory device using the direct mapping + * created by ->dirmap_create(). The function can return less + * data than requested (for example when the request is crossing + * the currently mapped area), and the caller of + * spi_mem_dirmap_write() is responsible for calling it again in + * this case. + * + * This interface should be implemented by SPI controllers providing an + * high-level interface to execute SPI memory operation, which is usually the + * case for QSPI controllers. + * + * Note on ->dirmap_{read,write}(): drivers should avoid accessing the direct + * mapping from the CPU because doing that can stall the CPU waiting for the + * SPI mem transaction to finish, and this will make real-time maintainers + * unhappy and might make your system less reactive. Instead, drivers should + * use DMA to access this direct mapping. + */ +struct spi_controller_mem_ops { + int (*adjust_op_size)(struct spi_mem *mem, struct spi_mem_op *op); + bool (*supports_op)(struct spi_mem *mem, + const struct spi_mem_op *op); + int (*exec_op)(struct spi_mem *mem, + const struct spi_mem_op *op); + const char *(*get_name)(struct spi_mem *mem); + int (*dirmap_create)(struct spi_mem_dirmap_desc *desc); + void (*dirmap_destroy)(struct spi_mem_dirmap_desc *desc); + ssize_t (*dirmap_read)(struct spi_mem_dirmap_desc *desc, + u64 offs, size_t len, void *buf); + ssize_t (*dirmap_write)(struct spi_mem_dirmap_desc *desc, + u64 offs, size_t len, const void *buf); +}; + +/** + * struct spi_mem_driver - SPI memory driver + * @spidrv: inherit from a SPI driver + * @probe: probe a SPI memory. Usually where detection/initialization takes + * place + * @remove: remove a SPI memory + * + * This is just a thin wrapper around a spi_driver. The core takes care of + * allocating the spi_mem object and forwarding the probe/remove + * request to the spi_mem_driver. The reason we use this wrapper is because + * we might have to stuff more information into the spi_mem struct to let + * SPI controllers know more about the SPI memory they interact with, and + * having this intermediate layer allows us to do that without adding more + * useless fields to the spi_device object. + */ +struct spi_mem_driver { + struct driver_d spidrv; + int (*probe)(struct spi_mem *mem); + int (*remove)(struct spi_mem *mem); +}; + +int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op); + +bool spi_mem_supports_op(struct spi_mem *mem, + const struct spi_mem_op *op); + +int spi_mem_exec_op(struct spi_mem *mem, + const struct spi_mem_op *op); + +const char *spi_mem_get_name(struct spi_mem *mem); + +struct spi_mem_dirmap_desc * +spi_mem_dirmap_create(struct spi_mem *mem, + const struct spi_mem_dirmap_info *info); +void spi_mem_dirmap_destroy(struct spi_mem_dirmap_desc *desc); +ssize_t spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc, + u64 offs, size_t len, void *buf); +ssize_t spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc, + u64 offs, size_t len, const void *buf); + +#endif /* __LINUX_SPI_MEM_H */ diff --git a/include/spi/spi.h b/include/spi/spi.h index 6eeaf254c7..bdcda0bb60 100644 --- a/include/spi/spi.h +++ b/include/spi/spi.h @@ -2,8 +2,12 @@ #define __INCLUDE_SPI_H #include <driver.h> +#include <linux/err.h> +#include <linux/kernel.h> #include <linux/string.h> +struct spi_controller_mem_ops; + struct spi_board_info { char *name; int max_speed_hz; @@ -62,6 +66,7 @@ struct spi_device { struct device_d dev; struct spi_controller *controller; struct spi_controller *master; /* compatibility layer */ + struct spi_mem *mem; u32 max_speed_hz; u8 chip_select; u8 mode; @@ -109,6 +114,13 @@ struct spi_message; * @dev: device interface to this driver * @bus_num: board-specific (and often SOC-specific) identifier for a * given SPI controller. + * @mem_ops: optimized/dedicated operations for interactions with SPI + * memory. This field is optional and should only be implemented + * if the controller has native support for memory like operations. + * @max_transfer_size: function that returns the max transfer size for + * a &spi_device; may be %NULL, so the default %SIZE_MAX will be used. + * @max_message_size: function that returns the max message size for + * a &spi_device; may be %NULL, so the default %SIZE_MAX will be used. * @num_chipselect: chipselects are used to distinguish individual * SPI slaves, and are numbered from zero to num_chipselects. * each slave has a chipselect signal, but it's common that not @@ -144,6 +156,15 @@ struct spi_controller { */ s16 bus_num; + /* Optimized handlers for SPI memory-like operations */ + const struct spi_controller_mem_ops *mem_ops; + /* + * on some hardware transfer size may be constrained + * the limit may depend on device transfer settings + */ + size_t (*max_transfer_size)(struct spi_device *spi); + size_t (*max_message_size)(struct spi_device *spi); + /* chipselects will be integral to many controllers; some others * might use board-specific GPIOs. */ @@ -180,6 +201,40 @@ struct spi_controller { struct list_head list; }; +static inline void *spi_controller_get_devdata(struct spi_controller *ctlr) +{ + if (ctlr->dev->platform_data) + return ctlr->dev->platform_data; + else + return ERR_PTR(-EINVAL); +} + +static inline void spi_controller_set_devdata(struct spi_controller *ctlr, + void *data) +{ + ctlr->dev->platform_data = data; +} + +static inline size_t spi_max_message_size(struct spi_device *spi) +{ + struct spi_controller *ctrl = spi->controller; + if (!ctrl->max_transfer_size) + return SIZE_MAX; + return ctrl->max_transfer_size(spi); +} + +static inline size_t spi_max_transfer_size(struct spi_device *spi) +{ + struct spi_controller *ctrl = spi->controller; + size_t tr_max = SIZE_MAX; + size_t msg_max = spi_max_message_size(spi); + + if (ctrl->max_transfer_size) + tr_max = ctrl->max_transfer_size(spi); + + return min(tr_max, msg_max); +} + #define spi_master spi_controller #define spi_register_master(_ctrl) spi_register_controller(_ctrl) |