alistair23-linux/include/linux/mmc/host.h
Philip Langdale 55556da012 MMC: Fix handling of low-voltage cards
Fix handling of low voltage MMC cards.

The latest MMC and SD specs both agree that support for
low-voltage operations is indicated by bit 7 in the OCR.
The MMC spec states that the low voltage range is
1.65-1.95V while the SD spec leaves the actual voltage
range undefined - meaning that there is still no such
thing as a low voltage SD card.

However, an old Sandisk spec implied that bits 7.0
represented voltages below 2.0V in 1V or 0.5V increments,
and the code was accordingly written with that expectation.

This confusion meant that host drivers attempting to support
the typical low voltage (1.8V) would set the wrong bits in
the host OCR mask (usually bits 5 and/or 6) resulting in the
the low voltage mode never being used.

This change corrects the low voltage range and adds sanity
checks on the reserved bits (0-6) and for SD cards that
claim to support low-voltage operations.

Signed-off-by: Philip Langdale <philipl@overt.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01 14:14:50 +02:00

152 lines
4.8 KiB
C

/*
* linux/include/linux/mmc/host.h
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Host driver specific definitions.
*/
#ifndef LINUX_MMC_HOST_H
#define LINUX_MMC_HOST_H
#include <linux/mmc/core.h>
struct mmc_ios {
unsigned int clock; /* clock rate */
unsigned short vdd;
/* vdd stores the bit number of the selected voltage range from below. */
unsigned char bus_mode; /* command output mode */
#define MMC_BUSMODE_OPENDRAIN 1
#define MMC_BUSMODE_PUSHPULL 2
unsigned char chip_select; /* SPI chip select */
#define MMC_CS_DONTCARE 0
#define MMC_CS_HIGH 1
#define MMC_CS_LOW 2
unsigned char power_mode; /* power supply mode */
#define MMC_POWER_OFF 0
#define MMC_POWER_UP 1
#define MMC_POWER_ON 2
unsigned char bus_width; /* data bus width */
#define MMC_BUS_WIDTH_1 0
#define MMC_BUS_WIDTH_4 2
unsigned char timing; /* timing specification used */
#define MMC_TIMING_LEGACY 0
#define MMC_TIMING_MMC_HS 1
#define MMC_TIMING_SD_HS 2
};
struct mmc_host_ops {
void (*request)(struct mmc_host *host, struct mmc_request *req);
void (*set_ios)(struct mmc_host *host, struct mmc_ios *ios);
int (*get_ro)(struct mmc_host *host);
};
struct mmc_card;
struct device;
struct mmc_host {
struct device *parent;
struct device class_dev;
int index;
const struct mmc_host_ops *ops;
unsigned int f_min;
unsigned int f_max;
u32 ocr_avail;
#define MMC_VDD_165_195 0x00000080 /* VDD voltage 1.65 - 1.95 */
#define MMC_VDD_20_21 0x00000100 /* VDD voltage 2.0 ~ 2.1 */
#define MMC_VDD_21_22 0x00000200 /* VDD voltage 2.1 ~ 2.2 */
#define MMC_VDD_22_23 0x00000400 /* VDD voltage 2.2 ~ 2.3 */
#define MMC_VDD_23_24 0x00000800 /* VDD voltage 2.3 ~ 2.4 */
#define MMC_VDD_24_25 0x00001000 /* VDD voltage 2.4 ~ 2.5 */
#define MMC_VDD_25_26 0x00002000 /* VDD voltage 2.5 ~ 2.6 */
#define MMC_VDD_26_27 0x00004000 /* VDD voltage 2.6 ~ 2.7 */
#define MMC_VDD_27_28 0x00008000 /* VDD voltage 2.7 ~ 2.8 */
#define MMC_VDD_28_29 0x00010000 /* VDD voltage 2.8 ~ 2.9 */
#define MMC_VDD_29_30 0x00020000 /* VDD voltage 2.9 ~ 3.0 */
#define MMC_VDD_30_31 0x00040000 /* VDD voltage 3.0 ~ 3.1 */
#define MMC_VDD_31_32 0x00080000 /* VDD voltage 3.1 ~ 3.2 */
#define MMC_VDD_32_33 0x00100000 /* VDD voltage 3.2 ~ 3.3 */
#define MMC_VDD_33_34 0x00200000 /* VDD voltage 3.3 ~ 3.4 */
#define MMC_VDD_34_35 0x00400000 /* VDD voltage 3.4 ~ 3.5 */
#define MMC_VDD_35_36 0x00800000 /* VDD voltage 3.5 ~ 3.6 */
unsigned long caps; /* Host capabilities */
#define MMC_CAP_4_BIT_DATA (1 << 0) /* Can the host do 4 bit transfers */
#define MMC_CAP_MULTIWRITE (1 << 1) /* Can accurately report bytes sent to card on error */
#define MMC_CAP_BYTEBLOCK (1 << 2) /* Can do non-log2 block sizes */
#define MMC_CAP_MMC_HIGHSPEED (1 << 3) /* Can do MMC high-speed timing */
#define MMC_CAP_SD_HIGHSPEED (1 << 4) /* Can do SD high-speed timing */
/* host specific block data */
unsigned int max_seg_size; /* see blk_queue_max_segment_size */
unsigned short max_hw_segs; /* see blk_queue_max_hw_segments */
unsigned short max_phys_segs; /* see blk_queue_max_phys_segments */
unsigned short unused;
unsigned int max_req_size; /* maximum number of bytes in one req */
unsigned int max_blk_size; /* maximum size of one mmc block */
unsigned int max_blk_count; /* maximum number of blocks in one req */
/* private data */
spinlock_t lock; /* lock for claim and bus ops */
struct mmc_ios ios; /* current io bus settings */
u32 ocr; /* the current OCR setting */
unsigned int mode; /* current card mode of host */
#define MMC_MODE_MMC 0
#define MMC_MODE_SD 1
struct mmc_card *card; /* device attached to this host */
wait_queue_head_t wq;
unsigned int claimed:1; /* host exclusively claimed */
struct delayed_work detect;
#ifdef CONFIG_MMC_DEBUG
unsigned int removed:1; /* host is being removed */
#endif
const struct mmc_bus_ops *bus_ops; /* current bus driver */
unsigned int bus_refs; /* reference counter */
unsigned int bus_dead:1; /* bus has been released */
unsigned long private[0] ____cacheline_aligned;
};
extern struct mmc_host *mmc_alloc_host(int extra, struct device *);
extern int mmc_add_host(struct mmc_host *);
extern void mmc_remove_host(struct mmc_host *);
extern void mmc_free_host(struct mmc_host *);
static inline void *mmc_priv(struct mmc_host *host)
{
return (void *)host->private;
}
#define mmc_dev(x) ((x)->parent)
#define mmc_classdev(x) (&(x)->class_dev)
#define mmc_hostname(x) ((x)->class_dev.bus_id)
extern int mmc_suspend_host(struct mmc_host *, pm_message_t);
extern int mmc_resume_host(struct mmc_host *);
extern void mmc_detect_change(struct mmc_host *, unsigned long delay);
extern void mmc_request_done(struct mmc_host *, struct mmc_request *);
#endif