MMC
MMC 特性
- Compatible with Secure Digital Memory (SD mem-version 2.0)
- Compatible with Secure Digital I/O (SDIO-version 3.0)
- Compatible with embedded MultiMediaCard (eMMC-version 5.0)
- Supports Card insertion and removal interrupt
- Supports hardware CRC generation and error detection
- Supports programmable baud rate
- Supports SDIO interrupts in 1-bit and 4-bit modes
- Supports block size of 1 to 65535 bytes
- Supports descriptor-based internal DMA controller
- Internal 1024-Bytes RX FIFO and 1024-Bytes TX FIFO
- Supports 1-bit, 4-bit SD and SDIO data bus width
- Supports 1-bit, 4-bit eMMC data bus width
模块介绍
RTOS 提供了MMC 子系统来实现对各种SD/SDIO 设备访问，MMC 子系统由上到下可以分为三层，MMC/SD card 层，MMC/SD core 层以及MMC/SD host 层，它们之间的层次关系如下所示。
MMC/SD card 层负主要是按照RTOS 块设备驱动程序的框架实现一个卡的块设备驱动。负责块设备请求的处理，以及请求队列的管理。MMC/SD core 层负责通信协议的处理，包括SD/SDIO，为上一层提供具体读写接口，同时为下一层提供host 端接口。MMC/SD host 是实现对SD/MMC 控制器相关的操作，直接操作硬件，也是主要实现部分。
模块配置
其 menuconfig 的配置如下：
Kernel Setup --->
Drivers Setup --->
SoC HAL Drivers --->
SDMMC devices --->
[*] enable SDMMC drivers
-*- enable SD
[*] enable SDIO
[ ] enable mmc
[ ] enable emmc
[ ] enable detect card
[*] enable dma transmission
[*] enable sdio irq
[*] enable SD Card test case.
(64) SD Card Align DMA Buffer Size(Kbyte).
(0) sdc card detect pin present value
[*] support SDMMC filesystem
源码结构
MMC 模块源码结构如下所示：
.
├── cmd
│ ├── cmd_sd.c
│ └── Kconfig
├── core.c
├── _core.h
├── hal
│ └── hal_ccm.c
├── hal_sdhost.c
├── hal_sdpin.c
├── Kconfig
├── Makefile
├── mmc.c
├── _mmc.h
├── osal
│ ├── Makefile
│ └── os
│ ├── FreeRTOS
│ │ ├── Makefile
│ │ ├── os_debug.c
│ │ ├── os_debug.h
│ │ ├── os_mutex.c
│ │ ├── os_queue.c
│ │ ├── os_semaphore.c
│ │ ├── os_thread.c
│ │ ├── os_timer.c
│ │ └── os_util.h
│ ├── Kconfig
│ └── Makefile
├── platform
│ └── mmc_sun20iw2p1.h
├── platform_mmc.h
├── quirks.c
├── sd.c
├── _sd_define.h
├── _sd.h
├── _sdhost.h
├── sdio.c
├── _sdio.h
├── sdio_irq.c
└── test.c
模块接口说明
SDMMC 接口
/**
* @brief read SD card.
* @param card:
* @arg card->card handler.
* @param buf:
* @arg buf->for store readed data.
* @param sblk:
* @arg sblk->start block num.
* @param nblk:
* @arg nblk->number of blocks.
* @retval 0 if success or other if failed.
*/
extern int32_t mmc_block_read(struct mmc_card *card, uint8_t *buf, uint64_t sblk, uint32_t nblk);
/**
* @brief write SD card.
* @param card:
* @arg card->card handler.
* @param buf:
* @arg buf->data will be write.
* @param sblk:
* @arg sblk->start block num.
* @param nblk:
* @arg nblk->number of blocks.
* @retval 0 if success or other if failed.
*/
extern int32_t mmc_block_write(struct mmc_card *card, const uint8_t *buf, uint64_t sblk, uint32_t nblk);
/**
* @brief scan or rescan SD card.
* @param card:
* @arg card->card handler.
* @param sdc_id:
* @arg sdc_id->SDC ID which card on.
* @retval 0 if success or other if failed.
*/
extern int32_t mmc_rescan(struct mmc_card *card, uint32_t sdc_id);
/**
* @brief deinit SD card.
* @param card:
* @arg card->card handler.
* @retval 0 if success or other if failed.
*/
extern int32_t mmc_card_deinit(struct mmc_card *card);
/**
* @brief malloc for card_info.
* @param card_id:
* @arg card ID.
* @retval 0 if success or other if failed.
*/
extern int32_t mmc_card_create(uint8_t card_id, SDCard_InitTypeDef *param);
/**
* @brief free for card_info.
* @param card_id:
* @arg card ID.
* @retval 0 if success or other if failed.
*/
extern int32_t mmc_card_delete(uint8_t card_id);
/**
* @brief get pointer of mmc_card.
* @param card_id:
* @arg card ID.
* @retval pointer of mmc_card if success or NULL if failed.
*/
extern struct mmc_card* mmc_card_open(uint8_t card_id);
/**
* @brief close mmc_card.
* @param card_id:
* @arg card ID.
* @retval 0 if success or other if failed.
*/
extern int32_t mmc_card_close(uint8_t card_id);
extern struct mmc_card_info* mmc_card_save(uint8_t card_id);
extern int32_t mmc_card_restore(struct mmc_card_info *s_card_info);
SDIO 接口
typedef struct mmc_card sdio_t;
/**
* sdio_readb - read a single byte from a SDIO function
* @card: SDIO to access
* @addr: address to read
* @err_ret: optional status value from transfer
*
* Reads a single byte from the address space of a given SDIO
* function. If there is a problem reading the address, 0xff
* is returned and @err_ret will contain the error code.
*/
extern uint8_t
sdio_readb(struct mmc_card *card, uint32_t func_num, uint32_t addr,
int32_t *err_ret);
/**
* sdio_writeb - write a single byte to a SDIO function
* @card: SDIO to access
* @b: byte to write
* @addr: address to write to
* @err_ret: optional status value from transfer
*
* Writes a single byte to the address space of a given SDIO
* function. @err_ret will contain the status of the actual
* transfer.
*/
extern void
sdio_writeb(struct mmc_card *card, uint32_t func_num, const uint8_t b,
uint32_t addr, int32_t *err_ret);
/**
* sdio_readw - read a 16 bit integer from a SDIO function
* @func: SDIO function to access
* @addr: address to read
* @err_ret: optional status value from transfer
*
* Reads a 16 bit integer from the address space of a given SDIO
* function. If there is a problem reading the address, 0xffff
* is returned and @err_ret will contain the error code.
*/
extern uint16_t sdio_readw(struct sdio_func *func, unsigned int addr, int *err_ret);
/**
* sdio_writew - write a 16 bit integer to a SDIO function
* @func: SDIO function to access
* @b: integer to write
* @addr: address to write to
* @err_ret: optional status value from transfer
*
* Writes a 16 bit integer to the address space of a given SDIO
* function. @err_ret will contain the status of the actual
* transfer.
*/
extern void sdio_writew(struct sdio_func *func, uint16_t b, unsigned int addr, int *err_ret);
/**
* sdio_readl - read a 32 bit integer from a SDIO function
* @func: SDIO function to access
* @addr: address to read
* @err_ret: optional status value from transfer
*
* Reads a 32 bit integer from the address space of a given SDIO
* function. If there is a problem reading the address,
* 0xffffffff is returned and @err_ret will contain the error
* code.
*/
extern uint32_t sdio_readl(struct sdio_func *func, unsigned int addr, int *err_ret);
/**
* sdio_writel - write a 32 bit integer to a SDIO function
* @func: SDIO function to access
* @b: integer to write
* @addr: address to write to
* @err_ret: optional status value from transfer
*
* Writes a 32 bit integer to the address space of a given SDIO
* function. @err_ret will contain the status of the actual
* transfer.
*/
extern void sdio_writel(struct sdio_func *func, uint32_t b, unsigned int addr, int *err_ret);
/**
* memcpy_fromio - read a chunk of memory from a SDIO function
* @dst: buffer to store the data
* @addr: address to begin reading from
* @count: number of bytes to read
*
* Reads from the address space of a given SDIO function. Return
* value indicates if the transfer succeeded or not.
*/
extern int
sdio_memcpy_fromio(struct mmc_card *card, unsigned int func_num, void *dst,
unsigned int addr, int count);
/**
* memcpy_toio - write a chunk of memory to a SDIO function
* @addr: address to start writing to
* @src: buffer that contains the data to write
* @count: number of bytes to write
*
* Writes to the address space of a given SDIO function. Return
* value indicates if the transfer succeeded or not.
*/
extern int
sdio_memcpy_toio(struct mmc_card *card, unsigned int func_num, unsigned int addr,
const void *src, int count);
/**
* sdio_claim_irq - claim the IRQ for a SDIO function
* @card: SDIO card
* @func_num: function num
* @handler: IRQ handler callback
*
* Claim and activate the IRQ for the given SDIO function. The provided
* handler will be called when that IRQ is asserted. The host is always
* claimed already when the handler is called so the handler must not
* call sdio_claim_host() nor sdio_release_host().
*/
//extern int sdio_claim_irq(struct mmc_card *card, unsigned int func_num,
// sdio_irq_handler_t *handler);
extern int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler);
/**
* sdio_release_irq - release the IRQ for a SDIO function
* @card: SDIO card
* @func_num: function num
*
* Disable and release the IRQ for the given SDIO function.
*/
//extern int sdio_release_irq(struct mmc_card *card, unsigned int func_num);
extern int sdio_release_irq(struct sdio_func *func);
/**
* sdio_align_size - pads a transfer size to a more optimal value
* @func: SDIO function
* @sz: original transfer size
*
* Pads the original data size with a number of extra bytes in
* order to avoid controller bugs and/or performance hits
* (e.g. some controllers revert to PIO for certain sizes).
*
* If possible, it will also adjust the size so that it can be
* handled in just a single request.
*
* Returns the improved size, which might be unmodified.
*/
//unsigned int sdio_align_size(struct mmc_card *card, unsigned int sz);
unsigned int sdio_align_size(struct sdio_func *func, unsigned int sz);