spi: Extend the core to ease integration of SPI memory controllers
authorBoris Brezillon <boris.brezillon@bootlin.com>
Thu, 16 Aug 2018 15:30:11 +0000 (17:30 +0200)
committerJagan Teki <jagan@amarulasolutions.com>
Thu, 20 Sep 2018 14:40:49 +0000 (20:10 +0530)
Some controllers are exposing high-level interfaces to access various
kind of SPI memories. Unfortunately they do not fit in the current
spi_controller model and usually have drivers placed in
drivers/mtd/spi-nor which are only supporting SPI NORs and not SPI
memories in general.

This is an attempt at defining a SPI memory interface which works for
all kinds of SPI memories (NORs, NANDs, SRAMs).

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jagan Teki <jagan@openedev.com>
drivers/spi/Kconfig
drivers/spi/Makefile
drivers/spi/spi-mem.c [new file with mode: 0644]
include/spi-mem.h [new file with mode: 0644]
include/spi.h

index dcd719ff0ac6416934a6fc132dcadc9fd0b154e3..9fbd26740d33dd816a33fad64e6506ce8388b8de 100644 (file)
@@ -18,6 +18,13 @@ config DM_SPI
 
 if DM_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 an high-level interface to send memory-like commands.
+
 config ALTERA_SPI
        bool "Altera SPI driver"
        help
index 728e30c5383c16b1bf39c052da73984b52b2160a..bdb5b5a02fd5585c6152df669055765087849dc4 100644 (file)
@@ -8,6 +8,7 @@ ifdef CONFIG_DM_SPI
 obj-y += spi-uclass.o
 obj-$(CONFIG_SANDBOX) += spi-emul-uclass.o
 obj-$(CONFIG_SOFT_SPI) += soft_spi.o
+obj-$(CONFIG_SPI_MEM) += spi-mem.o
 else
 obj-y += spi.o
 obj-$(CONFIG_SOFT_SPI) += soft_spi_legacy.o
diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
new file mode 100644 (file)
index 0000000..af9aef0
--- /dev/null
@@ -0,0 +1,501 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 Exceet Electronics GmbH
+ * Copyright (C) 2018 Bootlin
+ *
+ * Author: Boris Brezillon <boris.brezillon@bootlin.com>
+ */
+
+#ifndef __UBOOT__
+#include <linux/dmaengine.h>
+#include <linux/pm_runtime.h>
+#include "internals.h"
+#else
+#include <spi.h>
+#include <spi-mem.h>
+#endif
+
+#ifndef __UBOOT__
+/**
+ * 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);
+#endif /* __UBOOT__ */
+
+static int spi_check_buswidth_req(struct spi_slave *slave, u8 buswidth, bool tx)
+{
+       u32 mode = slave->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;
+
+       default:
+               break;
+       }
+
+       return -ENOTSUPP;
+}
+
+bool spi_mem_default_supports_op(struct spi_slave *slave,
+                                const struct spi_mem_op *op)
+{
+       if (spi_check_buswidth_req(slave, op->cmd.buswidth, true))
+               return false;
+
+       if (op->addr.nbytes &&
+           spi_check_buswidth_req(slave, op->addr.buswidth, true))
+               return false;
+
+       if (op->dummy.nbytes &&
+           spi_check_buswidth_req(slave, op->dummy.buswidth, true))
+               return false;
+
+       if (op->data.nbytes &&
+           spi_check_buswidth_req(slave, op->data.buswidth,
+                                  op->data.dir == SPI_MEM_DATA_OUT))
+               return false;
+
+       return true;
+}
+EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);
+
+/**
+ * spi_mem_supports_op() - Check if a memory device and the controller it is
+ *                        connected to support a specific memory operation
+ * @slave: the SPI device
+ * @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_slave *slave,
+                        const struct spi_mem_op *op)
+{
+       struct udevice *bus = slave->dev->parent;
+       struct dm_spi_ops *ops = spi_get_ops(bus);
+
+       if (ops->mem_ops && ops->mem_ops->supports_op)
+               return ops->mem_ops->supports_op(slave, op);
+
+       return spi_mem_default_supports_op(slave, op);
+}
+EXPORT_SYMBOL_GPL(spi_mem_supports_op);
+
+/**
+ * spi_mem_exec_op() - Execute a memory operation
+ * @slave: the SPI device
+ * @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_slave *slave, const struct spi_mem_op *op)
+{
+       struct udevice *bus = slave->dev->parent;
+       struct dm_spi_ops *ops = spi_get_ops(bus);
+       unsigned int pos = 0;
+       const u8 *tx_buf = NULL;
+       u8 *rx_buf = NULL;
+       u8 *op_buf;
+       int op_len;
+       u32 flag;
+       int ret;
+       int i;
+
+       if (!spi_mem_supports_op(slave, op))
+               return -ENOTSUPP;
+
+       if (ops->mem_ops) {
+#ifndef __UBOOT__
+               /*
+                * 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);
+#endif
+               ret = ops->mem_ops->exec_op(slave, op);
+#ifndef __UBOOT__
+               mutex_unlock(&ctlr->io_mutex);
+               mutex_unlock(&ctlr->bus_lock_mutex);
+
+               if (ctlr->auto_runtime_pm)
+                       pm_runtime_put(ctlr->dev.parent);
+#endif
+
+               /*
+                * 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;
+       }
+
+#ifndef __UBOOT__
+       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;
+       }
+
+       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;
+               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(slave, &msg);
+
+       kfree(tmpbuf);
+
+       if (ret)
+               return ret;
+
+       if (msg.actual_length != totalxferlen)
+               return -EIO;
+#else
+
+       /* U-Boot does not support parallel SPI data lanes */
+       if ((op->cmd.buswidth != 1) ||
+           (op->addr.nbytes && op->addr.buswidth != 1) ||
+           (op->dummy.nbytes && op->dummy.buswidth != 1) ||
+           (op->data.nbytes && op->data.buswidth != 1)) {
+               printf("Dual/Quad raw SPI transfers not supported\n");
+               return -ENOTSUPP;
+       }
+
+       if (op->data.nbytes) {
+               if (op->data.dir == SPI_MEM_DATA_IN)
+                       rx_buf = op->data.buf.in;
+               else
+                       tx_buf = op->data.buf.out;
+       }
+
+       op_len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes;
+       op_buf = calloc(1, op_len);
+
+       ret = spi_claim_bus(slave);
+       if (ret < 0)
+               return ret;
+
+       op_buf[pos++] = op->cmd.opcode;
+
+       if (op->addr.nbytes) {
+               for (i = 0; i < op->addr.nbytes; i++)
+                       op_buf[pos + i] = op->addr.val >>
+                               (8 * (op->addr.nbytes - i - 1));
+
+               pos += op->addr.nbytes;
+       }
+
+       if (op->dummy.nbytes)
+               memset(op_buf + pos, 0xff, op->dummy.nbytes);
+
+       /* 1st transfer: opcode + address + dummy cycles */
+       flag = SPI_XFER_BEGIN;
+       /* Make sure to set END bit if no tx or rx data messages follow */
+       if (!tx_buf && !rx_buf)
+               flag |= SPI_XFER_END;
+
+       ret = spi_xfer(slave, op_len * 8, op_buf, NULL, flag);
+       if (ret)
+               return ret;
+
+       /* 2nd transfer: rx or tx data path */
+       if (tx_buf || rx_buf) {
+               ret = spi_xfer(slave, op->data.nbytes * 8, tx_buf,
+                              rx_buf, SPI_XFER_END);
+               if (ret)
+                       return ret;
+       }
+
+       spi_release_bus(slave);
+
+       for (i = 0; i < pos; i++)
+               debug("%02x ", op_buf[i]);
+       debug("| [%dB %s] ",
+             tx_buf || rx_buf ? op->data.nbytes : 0,
+             tx_buf || rx_buf ? (tx_buf ? "out" : "in") : "-");
+       for (i = 0; i < op->data.nbytes; i++)
+               debug("%02x ", tx_buf ? tx_buf[i] : rx_buf[i]);
+       debug("[ret %d]\n", ret);
+
+       free(op_buf);
+
+       if (ret < 0)
+               return ret;
+#endif /* __UBOOT__ */
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(spi_mem_exec_op);
+
+/**
+ * spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to
+ *                              match controller limitations
+ * @slave: the SPI device
+ * @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_slave *slave, struct spi_mem_op *op)
+{
+       struct udevice *bus = slave->dev->parent;
+       struct dm_spi_ops *ops = spi_get_ops(bus);
+
+       if (ops->mem_ops && ops->mem_ops->adjust_op_size)
+               return ops->mem_ops->adjust_op_size(slave, op);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size);
+
+#ifndef __UBOOT__
+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_probe(struct spi_device *spi)
+{
+       struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
+       struct spi_mem *mem;
+
+       mem = devm_kzalloc(&spi->dev, sizeof(*mem), GFP_KERNEL);
+       if (!mem)
+               return -ENOMEM;
+
+       mem->spi = spi;
+       spi_set_drvdata(spi, mem);
+
+       return memdrv->probe(mem);
+}
+
+static int 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)
+               return memdrv->remove(mem);
+
+       return 0;
+}
+
+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_with_owner() - 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);
+#endif /* __UBOOT__ */
diff --git a/include/spi-mem.h b/include/spi-mem.h
new file mode 100644 (file)
index 0000000..36814ef
--- /dev/null
@@ -0,0 +1,258 @@
+/* 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 __UBOOT_SPI_MEM_H
+#define __UBOOT_SPI_MEM_H
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <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_DATA_IN: data coming from the SPI memory
+ * @SPI_MEM_DATA_OUT: data sent the SPI memory
+ */
+enum spi_mem_data_dir {
+       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.buf.in: input buffer
+ * @data.buf.out: output buffer
+ */
+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;
+               /* buf.{in,out} must be DMA-able. */
+               union {
+                       void *in;
+                       const void *out;
+               } buf;
+       } data;
+};
+
+#define SPI_MEM_OP(__cmd, __addr, __dummy, __data)             \
+       {                                                       \
+               .cmd = __cmd,                                   \
+               .addr = __addr,                                 \
+               .dummy = __dummy,                               \
+               .data = __data,                                 \
+       }
+
+#ifndef __UBOOT__
+/**
+ * struct spi_mem - describes a SPI memory device
+ * @spi: the underlying SPI device
+ * @drvpriv: spi_mem_driver private data
+ *
+ * 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 udevice *dev;
+       void *drvpriv;
+};
+
+/**
+ * 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;
+}
+#endif /* __UBOOT__ */
+
+/**
+ * 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
+ *
+ * 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.
+ */
+struct spi_controller_mem_ops {
+       int (*adjust_op_size)(struct spi_slave *slave, struct spi_mem_op *op);
+       bool (*supports_op)(struct spi_slave *slave,
+                           const struct spi_mem_op *op);
+       int (*exec_op)(struct spi_slave *slave,
+                      const struct spi_mem_op *op);
+};
+
+#ifndef __UBOOT__
+/**
+ * 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
+ * @shutdown: take appropriate action when the system is shutdown
+ *
+ * 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/shutdown
+ * 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 spi_driver spidrv;
+       int (*probe)(struct spi_mem *mem);
+       int (*remove)(struct spi_mem *mem);
+       void (*shutdown)(struct spi_mem *mem);
+};
+
+#if IS_ENABLED(CONFIG_SPI_MEM)
+int spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
+                                      const struct spi_mem_op *op,
+                                      struct sg_table *sg);
+
+void spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
+                                         const struct spi_mem_op *op,
+                                         struct sg_table *sg);
+#else
+static inline int
+spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
+                                  const struct spi_mem_op *op,
+                                  struct sg_table *sg)
+{
+       return -ENOTSUPP;
+}
+
+static inline void
+spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
+                                    const struct spi_mem_op *op,
+                                    struct sg_table *sg)
+{
+}
+#endif /* CONFIG_SPI_MEM */
+#endif /* __UBOOT__ */
+
+int spi_mem_adjust_op_size(struct spi_slave *slave, struct spi_mem_op *op);
+
+bool spi_mem_supports_op(struct spi_slave *slave, const struct spi_mem_op *op);
+
+int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op);
+
+#ifndef __UBOOT__
+int spi_mem_driver_register_with_owner(struct spi_mem_driver *drv,
+                                      struct module *owner);
+
+void spi_mem_driver_unregister(struct spi_mem_driver *drv);
+
+#define spi_mem_driver_register(__drv)                                  \
+       spi_mem_driver_register_with_owner(__drv, THIS_MODULE)
+
+#define module_spi_mem_driver(__drv)                                    \
+       module_driver(__drv, spi_mem_driver_register,                   \
+                     spi_mem_driver_unregister)
+#endif
+
+#endif /* __LINUX_SPI_MEM_H */
index 9754c53aa1486910dbf5aeb329b1808a57e0e360..938627bc012b57294365cc4b5ca4691d82dbf298 100644 (file)
@@ -9,6 +9,8 @@
 #ifndef _SPI_H_
 #define _SPI_H_
 
+#include <common.h>
+
 /* SPI mode flags */
 #define SPI_CPHA       BIT(0)                  /* clock phase */
 #define SPI_CPOL       BIT(1)                  /* clock polarity */
@@ -402,6 +404,15 @@ struct dm_spi_ops {
        int (*xfer)(struct udevice *dev, unsigned int bitlen, const void *dout,
                    void *din, unsigned long flags);
 
+       /**
+        * Optimized handlers for SPI memory-like operations.
+        *
+        * 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.
+        */
+       const struct spi_controller_mem_ops *mem_ops;
+
        /**
         * Set transfer speed.
         * This sets a new speed to be applied for next spi_xfer().