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Diffstat (limited to 'include/linux/spi/spi-mem.h')
| -rw-r--r-- | include/linux/spi/spi-mem.h | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h new file mode 100644 index 000000000000..bb4bd15ae1f6 --- /dev/null +++ b/include/linux/spi/spi-mem.h @@ -0,0 +1,249 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (C) 2018 Exceet Electronics GmbH + * Copyright (C) 2018 Bootlin + * + * Author: Boris Brezillon <boris.brezillon@bootlin.com> + */ + +#ifndef __LINUX_SPI_MEM_H +#define __LINUX_SPI_MEM_H + +#include <linux/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_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, \ + } + +/** + * struct spi_mem - describes a SPI memory device + * @spi: the underlying SPI device + * @drvpriv: spi_mem_drviver 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 spi_device *spi; + 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; +} + +/** + * 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_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); +}; + +/** + * 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 */ + +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); + +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 /* __LINUX_SPI_MEM_H */ |