include/linux/spi/spi-mem.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * Copyright (C) 2018 Exceet Electronics GmbH
   4  * Copyright (C) 2018 Bootlin
   5  *
   6  * Author:
   7  *      Peter Pan <peterpandong@micron.com>
   8  *      Boris Brezillon <boris.brezillon@bootlin.com>
   9  */
  10
  11 #ifndef __LINUX_SPI_MEM_H
  12 #define __LINUX_SPI_MEM_H
  13
  14 #include <linux/spi/spi.h>
  15
  16 #define SPI_MEM_OP_CMD(__opcode, __buswidth)                    \
  17         {                                                       \
  18                 .buswidth = __buswidth,                         \
  19                 .opcode = __opcode,                             \
  20         }
  21
  22 #define SPI_MEM_OP_ADDR(__nbytes, __val, __buswidth)            \
  23         {                                                       \
  24                 .nbytes = __nbytes,                             \
  25                 .val = __val,                                   \
  26                 .buswidth = __buswidth,                         \
  27         }
  28
  29 #define SPI_MEM_OP_NO_ADDR      { }
  30
  31 #define SPI_MEM_OP_DUMMY(__nbytes, __buswidth)                  \
  32         {                                                       \
  33                 .nbytes = __nbytes,                             \
  34                 .buswidth = __buswidth,                         \
  35         }
  36
  37 #define SPI_MEM_OP_NO_DUMMY     { }
  38
  39 #define SPI_MEM_OP_DATA_IN(__nbytes, __buf, __buswidth)         \
  40         {                                                       \
  41                 .dir = SPI_MEM_DATA_IN,                         \
  42                 .nbytes = __nbytes,                             \
  43                 .buf.in = __buf,                                \
  44                 .buswidth = __buswidth,                         \
  45         }
  46
  47 #define SPI_MEM_OP_DATA_OUT(__nbytes, __buf, __buswidth)        \
  48         {                                                       \
  49                 .dir = SPI_MEM_DATA_OUT,                        \
  50                 .nbytes = __nbytes,                             \
  51                 .buf.out = __buf,                               \
  52                 .buswidth = __buswidth,                         \
  53         }
  54
  55 #define SPI_MEM_OP_NO_DATA      { }
  56
  57 /**
  58  * enum spi_mem_data_dir - describes the direction of a SPI memory data
  59  *                         transfer from the controller perspective
  60  * @SPI_MEM_DATA_IN: data coming from the SPI memory
  61  * @SPI_MEM_DATA_OUT: data sent the SPI memory
  62  */
  63 enum spi_mem_data_dir {
  64         SPI_MEM_DATA_IN,
  65         SPI_MEM_DATA_OUT,
  66 };
  67
  68 /**
  69  * struct spi_mem_op - describes a SPI memory operation
  70  * @cmd.buswidth: number of IO lines used to transmit the command
  71  * @cmd.opcode: operation opcode
  72  * @addr.nbytes: number of address bytes to send. Can be zero if the operation
  73  *               does not need to send an address
  74  * @addr.buswidth: number of IO lines used to transmit the address cycles
  75  * @addr.val: address value. This value is always sent MSB first on the bus.
  76  *            Note that only @addr.nbytes are taken into account in this
  77  *            address value, so users should make sure the value fits in the
  78  *            assigned number of bytes.
  79  * @dummy.nbytes: number of dummy bytes to send after an opcode or address. Can
  80  *                be zero if the operation does not require dummy bytes
  81  * @dummy.buswidth: number of IO lanes used to transmit the dummy bytes
  82  * @data.buswidth: number of IO lanes used to send/receive the data
  83  * @data.dir: direction of the transfer
  84  * @data.nbytes: number of data bytes to send/receive. Can be zero if the
  85  *               operation does not involve transferring data
  86  * @data.buf.in: input buffer (must be DMA-able)
  87  * @data.buf.out: output buffer (must be DMA-able)
  88  */
  89 struct spi_mem_op {
  90         struct {
  91                 u8 buswidth;
  92                 u8 opcode;
  93         } cmd;
  94
  95         struct {
  96                 u8 nbytes;
  97                 u8 buswidth;
  98                 u64 val;
  99         } addr;
 100
 101         struct {
 102                 u8 nbytes;
 103                 u8 buswidth;
 104         } dummy;
 105
 106         struct {
 107                 u8 buswidth;
 108                 enum spi_mem_data_dir dir;
 109                 unsigned int nbytes;
 110                 union {
 111                         void *in;
 112                         const void *out;
 113                 } buf;
 114         } data;
 115 };
 116
 117 #define SPI_MEM_OP(__cmd, __addr, __dummy, __data)              \
 118         {                                                       \
 119                 .cmd = __cmd,                                   \
 120                 .addr = __addr,                                 \
 121                 .dummy = __dummy,                               \
 122                 .data = __data,                                 \
 123         }
 124
 125 /**
 126  * struct spi_mem - describes a SPI memory device
 127  * @spi: the underlying SPI device
 128  * @drvpriv: spi_mem_driver private data
 129  * @name: name of the SPI memory device
 130  *
 131  * Extra information that describe the SPI memory device and may be needed by
 132  * the controller to properly handle this device should be placed here.
 133  *
 134  * One example would be the device size since some controller expose their SPI
 135  * mem devices through a io-mapped region.
 136  */
 137 struct spi_mem {
 138         struct spi_device *spi;
 139         void *drvpriv;
 140         const char *name;
 141 };
 142
 143 /**
 144  * struct spi_mem_set_drvdata() - attach driver private data to a SPI mem
 145  *                                device
 146  * @mem: memory device
 147  * @data: data to attach to the memory device
 148  */
 149 static inline void spi_mem_set_drvdata(struct spi_mem *mem, void *data)
 150 {
 151         mem->drvpriv = data;
 152 }
 153
 154 /**
 155  * struct spi_mem_get_drvdata() - get driver private data attached to a SPI mem
 156  *                                device
 157  * @mem: memory device
 158  *
 159  * Return: the data attached to the mem device.
 160  */
 161 static inline void *spi_mem_get_drvdata(struct spi_mem *mem)
 162 {
 163         return mem->drvpriv;
 164 }
 165
 166 /**
 167  * struct spi_controller_mem_ops - SPI memory operations
 168  * @adjust_op_size: shrink the data xfer of an operation to match controller's
 169  *                  limitations (can be alignment of max RX/TX size
 170  *                  limitations)
 171  * @supports_op: check if an operation is supported by the controller
 172  * @exec_op: execute a SPI memory operation
 173  * @get_name: get a custom name for the SPI mem device from the controller.
 174  *            This might be needed if the controller driver has been ported
 175  *            to use the SPI mem layer and a custom name is used to keep
 176  *            mtdparts compatible.
 177  *            Note that if the implementation of this function allocates memory
 178  *            dynamically, then it should do so with devm_xxx(), as we don't
 179  *            have a ->free_name() function.
 180  *
 181  * This interface should be implemented by SPI controllers providing an
 182  * high-level interface to execute SPI memory operation, which is usually the
 183  * case for QSPI controllers.
 184  */
 185 struct spi_controller_mem_ops {
 186         int (*adjust_op_size)(struct spi_mem *mem, struct spi_mem_op *op);
 187         bool (*supports_op)(struct spi_mem *mem,
 188                             const struct spi_mem_op *op);
 189         int (*exec_op)(struct spi_mem *mem,
 190                        const struct spi_mem_op *op);
 191         const char *(*get_name)(struct spi_mem *mem);
 192 };
 193
 194 /**
 195  * struct spi_mem_driver - SPI memory driver
 196  * @spidrv: inherit from a SPI driver
 197  * @probe: probe a SPI memory. Usually where detection/initialization takes
 198  *         place
 199  * @remove: remove a SPI memory
 200  * @shutdown: take appropriate action when the system is shutdown
 201  *
 202  * This is just a thin wrapper around a spi_driver. The core takes care of
 203  * allocating the spi_mem object and forwarding the probe/remove/shutdown
 204  * request to the spi_mem_driver. The reason we use this wrapper is because
 205  * we might have to stuff more information into the spi_mem struct to let
 206  * SPI controllers know more about the SPI memory they interact with, and
 207  * having this intermediate layer allows us to do that without adding more
 208  * useless fields to the spi_device object.
 209  */
 210 struct spi_mem_driver {
 211         struct spi_driver spidrv;
 212         int (*probe)(struct spi_mem *mem);
 213         int (*remove)(struct spi_mem *mem);
 214         void (*shutdown)(struct spi_mem *mem);
 215 };
 216
 217 #if IS_ENABLED(CONFIG_SPI_MEM)
 218 int spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
 219                                        const struct spi_mem_op *op,
 220                                        struct sg_table *sg);
 221
 222 void spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
 223                                           const struct spi_mem_op *op,
 224                                           struct sg_table *sg);
 225 #else
 226 static inline int
 227 spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
 228                                    const struct spi_mem_op *op,
 229                                    struct sg_table *sg)
 230 {
 231         return -ENOTSUPP;
 232 }
 233
 234 static inline void
 235 spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
 236                                      const struct spi_mem_op *op,
 237                                      struct sg_table *sg)
 238 {
 239 }
 240 #endif /* CONFIG_SPI_MEM */
 241
 242 int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op);
 243
 244 bool spi_mem_supports_op(struct spi_mem *mem,
 245                          const struct spi_mem_op *op);
 246
 247 int spi_mem_exec_op(struct spi_mem *mem,
 248                     const struct spi_mem_op *op);
 249
 250 const char *spi_mem_get_name(struct spi_mem *mem);
 251
 252 int spi_mem_driver_register_with_owner(struct spi_mem_driver *drv,
 253                                        struct module *owner);
 254
 255 void spi_mem_driver_unregister(struct spi_mem_driver *drv);
 256
 257 #define spi_mem_driver_register(__drv)                                  \
 258         spi_mem_driver_register_with_owner(__drv, THIS_MODULE)
 259
 260 #define module_spi_mem_driver(__drv)                                    \
 261         module_driver(__drv, spi_mem_driver_register,                   \
 262                       spi_mem_driver_unregister)
 263
 264 #endif /* __LINUX_SPI_MEM_H */