sdhci.h

struct sdhci_host {
	/* Data set by hardware interface driver */
	const char *hw_name;	/* Hardware bus name */

	unsigned int quirks;	/* Deviations from spec. */

/* 在复位前需要设置时钟 */
/* Controller doesn't honor resets unless we touch the clock register */
#define SDHCI_QUIRK_CLOCK_BEFORE_RESET			(1<<0)

/* 强制使用DMA */
/* Controller has bad caps bits, but really supports DMA */
#define SDHCI_QUIRK_FORCE_DMA				(1<<1)

/* 没有卡插入时不复位 */
/* Controller doesn't like to be reset when there is no card inserted. */
#define SDHCI_QUIRK_NO_CARD_NO_RESET			(1<<2)

/* 控制器不喜欢在MMC_VDD改变前清除电源寄存器 */
/* 遇到这个，直接改电源寄存器，不清除 */
/* Controller doesn't like clearing the power reg before a change */
#define SDHCI_QUIRK_SINGLE_POWER_WRITE			(1<<3)

/* 在sdhci_do_set_ios()中会用到 */
/* 解释：有些控制器在一些操作时会疯，即使是CMD0，解决方法就是复位每一个IOS */
/* Controller has flaky internal state so reset it on each ios change */
#define SDHCI_QUIRK_RESET_CMD_DATA_ON_IOS		(1<<4)

/* 控制器有一个不可使用的DMA引擎 */
/* Controller has an unusable DMA engine */
#define SDHCI_QUIRK_BROKEN_DMA				(1<<5)

/* ADMA: Advanced DMA */
/* 控制器有一个不可使用的ADMA引擎 */
/* Controller has an unusable ADMA engine */
#define SDHCI_QUIRK_BROKEN_ADMA				(1<<6)

/* DMA要32位地址对齐 */
/* Controller can only DMA from 32-bit aligned addresses */
#define SDHCI_QUIRK_32BIT_DMA_ADDR			(1<<7)

/* DMA的大小是32的倍数 */
/* Controller can only DMA chunk sizes that are a multiple of 32 bits */
#define SDHCI_QUIRK_32BIT_DMA_SIZE			(1<<8)

/* ADMA的大小是32位的倍数 */
/* Controller can only ADMA chunks that are a multiple of 32 bits */
#define SDHCI_QUIRK_32BIT_ADMA_SIZE			(1<<9)

/* 每个请求之后，控制器需要复位来爆出稳定 */
/* 在sdhci_tasklet_finish()中，即任务完成时， */
/* 当host->quirks & SDHCI_QUIRK_RESET_AFTER_REQUEST成立时，执行复位 */
/* Controller needs to be reset after each request to stay stable */
#define SDHCI_QUIRK_RESET_AFTER_REQUEST			(1<<10)

/* 控制器需要分别写入电压和电源 */
/* 这个标准是开启电源时，要先设置电压 */
/* Marvell CaFe芯片就是如此，代码上要先设置，再或上SDHCI_POWER_ON开启 */
/*     if (host->quirks & SDHCI_QUIRK_NO_SIMULT_VDD_AND_POWER) */
/*         sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL); */
/*     pwr |= SDHCI_POWER_ON; */
/*     sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL); */
/* Controller needs voltage and power writes to happen separately */
#define SDHCI_QUIRK_NO_SIMULT_VDD_AND_POWER		(1<<11)

/* 控制器提供了一个不正确的超时值 */
/* 会用0xE作为Timeout，就是让硬件有一个长的超时值，比短的好 */
/*     if (host->quirks & SDHCI_QUIRK_BROKEN_TIMEOUT_VAL) */
/*         return 0xE; */
/* Controller provides an incorrect timeout value for transfers */
#define SDHCI_QUIRK_BROKEN_TIMEOUT_VAL			(1<<12)

/* 控制器支持小字节传输 */
/* 有些控制器（例如：JMicron JMB38x)弄乱传输位，（小于4字节）。 */
/* 只要它有一个block,我们可以忽略这些位。 */
/* 寄存器PRNSTS(s3c6410有这个寄存器)的第11位(buffer read enable)会被忽略 */
/* Controller has an issue with buffer bits for small transfers */
#define SDHCI_QUIRK_BROKEN_SMALL_PIO			(1<<13)

/* 当不忙时，控制器不提供传输完成中断 */
/* Controller does not provide transfer-complete interrupt when not busy */
#define SDHCI_QUIRK_NO_BUSY_IRQ				(1<<14)

/* 不可靠的卡检测 */
/* Controller has unreliable card detection */
#define SDHCI_QUIRK_BROKEN_CARD_DETECTION		(1<<15)

/* 控制器报告反的写保护状态 */
/* Controller reports inverted write-protect state */
#define SDHCI_QUIRK_INVERTED_WRITE_PROTECT		(1<<16)

/* PIO传输需要延时 */
/* Controller does not like fast PIO transfers */
#define SDHCI_QUIRK_PIO_NEEDS_DELAY			(1<<18)

/* 强制块传输大小为2048 */
/* Controller has to be forced to use block size of 2048 bytes */
#define SDHCI_QUIRK_FORCE_BLK_SZ_2048			(1<<20)

/* 不支持多块传输 */
/* Controller cannot do multi-block transfers */
#define SDHCI_QUIRK_NO_MULTIBLOCK			(1<<21)

/* 强制1bit数据位传输 */
/* Controller can only handle 1-bit data transfers */
#define SDHCI_QUIRK_FORCE_1_BIT_DATA			(1<<22)

/* 上电之后需要延时10ms */
/* Controller needs 10ms delay between applying power and clock */
#define SDHCI_QUIRK_DELAY_AFTER_POWER			(1<<23)

/* 使用SDCLK作为数据超时时钟源 */
/* Controller uses SDCLK instead of TMCLK for data timeouts */
#define SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK		(1<<24)

/* 检测基本时钟错误的能力 */
/* Controller reports wrong base clock capability */
#define SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN		(1<<25)

/* 不支持NOP ADMA描述符中的End属性 */
/* Controller cannot support End Attribute in NOP ADMA descriptor */
#define SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC		(1<<26)

/* 使用主机提供的Caps */
/* Controller is missing device caps. Use caps provided by host */
#define SDHCI_QUIRK_MISSING_CAPS			(1<<27)

/* 支持使用Auto CMD12命令停止传输 */
/* Controller uses Auto CMD12 command to stop the transfer */
#define SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12		(1<<28)

/* 在HI-SPEED SD卡中没有HISPD位域 */
/* Controller doesn't have HISPD bit field in HI-SPEED SD card */
#define SDHCI_QUIRK_NO_HISPD_BIT			(1<<29)

/* 控制器会错误的处理长度为0x0000的ADMA描述符 */
/* Controller treats ADMA descriptors with length 0000h incorrectly */
#define SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC		(1<<30)

/* 通过SDHCI_PRESENT_STATE寄存器进行只读检测是不稳定的 */
/* The read-only detection via SDHCI_PRESENT_STATE register is unstable */
#define SDHCI_QUIRK_UNSTABLE_RO_DETECT			(1<<31)

	unsigned int quirks2;	/* More deviations from spec. */

#define SDHCI_QUIRK2_HOST_OFF_CARD_ON			(1<<0)
#define SDHCI_QUIRK2_HOST_NO_CMD23			(1<<1)
/* The system physically doesn't support 1.8v, even if the host does */
#define SDHCI_QUIRK2_NO_1_8_V				(1<<2)
#define SDHCI_QUIRK2_PRESET_VALUE_BROKEN		(1<<3)
#define SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON		(1<<4)
/* Controller has a non-standard host control register */
#define SDHCI_QUIRK2_BROKEN_HOST_CONTROL		(1<<5)
/* Controller does not support HS200 */
#define SDHCI_QUIRK2_BROKEN_HS200			(1<<6)
/* Controller does not support DDR50 */
#define SDHCI_QUIRK2_BROKEN_DDR50			(1<<7)
/* Stop command (CMD12) can set Transfer Complete when not using MMC_RSP_BUSY */
#define SDHCI_QUIRK2_STOP_WITH_TC			(1<<8)
/* Controller does not support 64-bit DMA */
#define SDHCI_QUIRK2_BROKEN_64_BIT_DMA			(1<<9)
/* need clear transfer mode register before send cmd */
#define SDHCI_QUIRK2_CLEAR_TRANSFERMODE_REG_BEFORE_CMD	(1<<10)
/* Capability register bit-63 indicates HS400 support */
#define SDHCI_QUIRK2_CAPS_BIT63_FOR_HS400		(1<<11)
/* forced tuned clock */
#define SDHCI_QUIRK2_TUNING_WORK_AROUND			(1<<12)
/* disable the block count for single block transactions */
#define SDHCI_QUIRK2_SUPPORT_SINGLE			(1<<13)
/* Controller broken with using ACMD23 */
#define SDHCI_QUIRK2_ACMD23_BROKEN			(1<<14)
/* Broken Clock divider zero in controller */
#define SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN		(1<<15)
/*
 * When internal clock is disabled, a delay is needed before modifying the
 * SD clock frequency or enabling back the internal clock.
 */
#define SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST	(1<<16)

	int irq;		/* Device IRQ */
	void __iomem *ioaddr;	/* Mapped address */

	const struct sdhci_ops *ops;	/* Low level hw interface */

	/* Internal data */
	struct mmc_host *mmc;	/* MMC structure */
	struct mmc_host_ops mmc_host_ops;	/* MMC host ops */
	u64 dma_mask;		/* custom DMA mask */

#if defined(CONFIG_LEDS_CLASS) || defined(CONFIG_LEDS_CLASS_MODULE)
	struct led_classdev led;	/* LED control */
	char led_name[32];
#endif

	spinlock_t lock;	/* Mutex */

	int flags;		/* Host attributes */
#define SDHCI_USE_SDMA		(1<<0)	/* Host is SDMA capable */
#define SDHCI_USE_ADMA		(1<<1)	/* Host is ADMA capable */
#define SDHCI_REQ_USE_DMA	(1<<2)	/* Use DMA for this req. */
#define SDHCI_DEVICE_DEAD	(1<<3)	/* Device unresponsive */
#define SDHCI_SDR50_NEEDS_TUNING (1<<4)	/* SDR50 needs tuning */
#define SDHCI_AUTO_CMD12	(1<<6)	/* Auto CMD12 support */
#define SDHCI_AUTO_CMD23	(1<<7)	/* Auto CMD23 support */
#define SDHCI_PV_ENABLED	(1<<8)	/* Preset value enabled */
#define SDHCI_SDIO_IRQ_ENABLED	(1<<9)	/* SDIO irq enabled */
#define SDHCI_SDR104_NEEDS_TUNING (1<<10)	/* SDR104/HS200 needs tuning */
#define SDHCI_USE_64_BIT_DMA	(1<<12)	/* Use 64-bit DMA */
#define SDHCI_HS400_TUNING	(1<<13)	/* Tuning for HS400 */

	unsigned int version;	/* SDHCI spec. version */

	unsigned int max_clk;	/* Max possible freq (MHz) */
	unsigned int timeout_clk;	/* Timeout freq (KHz) */
	unsigned int clk_mul;	/* Clock Muliplier value */

	unsigned int clock;	/* Current clock (MHz) */
	u8 pwr;			/* Current voltage */

	bool runtime_suspended;	/* Host is runtime suspended */
	bool bus_on;		/* Bus power prevents runtime suspend */
	bool preset_enabled;	/* Preset is enabled */

	struct mmc_request *mrq;	/* Current request */
	struct mmc_command *cmd;	/* Current command */
	struct mmc_data *data;	/* Current data request */
	unsigned int data_early:1;	/* Data finished before cmd */
	unsigned int busy_handle:1;	/* Handling the order of Busy-end */

	struct sg_mapping_iter sg_miter;	/* SG state for PIO */
	unsigned int blocks;	/* remaining PIO blocks */

	int sg_count;		/* Mapped sg entries */

	void *adma_table;	/* ADMA descriptor table */
	void *align_buffer;	/* Bounce buffer */

	size_t adma_table_sz;	/* ADMA descriptor table size */
	size_t align_buffer_sz;	/* Bounce buffer size */

	dma_addr_t adma_addr;	/* Mapped ADMA descr. table */
	dma_addr_t align_addr;	/* Mapped bounce buffer */

	unsigned int desc_sz;	/* ADMA descriptor size */

	struct tasklet_struct finish_tasklet;	/* Tasklet structures */

	struct timer_list timer;	/* Timer for timeouts */

	u32 caps;		/* Alternative CAPABILITY_0 */
	u32 caps1;		/* Alternative CAPABILITY_1 */

	unsigned int            ocr_avail_sdio;	/* OCR bit masks */
	unsigned int            ocr_avail_sd;
	unsigned int            ocr_avail_mmc;
	u32 ocr_mask;		/* available voltages */

	unsigned		timing;		/* Current timing */

	u32			thread_isr;

	/* cached registers */
	u32			ier;

	wait_queue_head_t	buf_ready_int;	/* Waitqueue for Buffer Read Ready interrupt */
	unsigned int		tuning_done;	/* Condition flag set when CMD19 succeeds */

	unsigned int		tuning_count;	/* Timer count for re-tuning */
	unsigned int		tuning_mode;	/* Re-tuning mode supported by host */
#define SDHCI_TUNING_MODE_1	0

	unsigned long private[0] ____cacheline_aligned;
};