From 7ccd266e676a3f0c6f8f897f58b684cac3dd1650 Mon Sep 17 00:00:00 2001 From: Pierre Ossman Date: Wed, 8 Nov 2006 23:03:10 +0100 Subject: [PATCH] mmc: Support for high speed SD cards Modern SD cards support a clock speed of 50 MHz. Make sure we test for this capability and do the song and dance required to activate it. Activating high speed support actually modifies the TRAN_SPEED field of the CSD. But as the spec says that the cards must report 50 MHz, we might as well skip re-reading the CSD. Signed-off-by: Pierre Ossman --- drivers/mmc/mmc.c | 122 +++++++++++++++++++++++++++++++++-- include/linux/mmc/card.h | 7 +- include/linux/mmc/protocol.h | 22 +++++++ 3 files changed, 146 insertions(+), 5 deletions(-) diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index 82b7643c1654..9d190022a490 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -1157,6 +1157,116 @@ static void mmc_read_scrs(struct mmc_host *host) mmc_deselect_cards(host); } +static void mmc_read_switch_caps(struct mmc_host *host) +{ + int err; + struct mmc_card *card; + struct mmc_request mrq; + struct mmc_command cmd; + struct mmc_data data; + unsigned char *status; + struct scatterlist sg; + + status = kmalloc(64, GFP_KERNEL); + if (!status) { + printk(KERN_WARNING "%s: Unable to allocate buffer for " + "reading switch capabilities.\n", + mmc_hostname(host)); + return; + } + + list_for_each_entry(card, &host->cards, node) { + if (card->state & (MMC_STATE_DEAD|MMC_STATE_PRESENT)) + continue; + if (!mmc_card_sd(card)) + continue; + if (card->scr.sda_vsn < SCR_SPEC_VER_1) + continue; + + err = mmc_select_card(host, card); + if (err != MMC_ERR_NONE) { + mmc_card_set_dead(card); + continue; + } + + memset(&cmd, 0, sizeof(struct mmc_command)); + + cmd.opcode = SD_SWITCH; + cmd.arg = 0x00FFFFF1; + cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC; + + memset(&data, 0, sizeof(struct mmc_data)); + + mmc_set_data_timeout(&data, card, 0); + + data.blksz = 64; + data.blocks = 1; + data.flags = MMC_DATA_READ; + data.sg = &sg; + data.sg_len = 1; + + memset(&mrq, 0, sizeof(struct mmc_request)); + + mrq.cmd = &cmd; + mrq.data = &data; + + sg_init_one(&sg, status, 64); + + mmc_wait_for_req(host, &mrq); + + if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE) { + mmc_card_set_dead(card); + continue; + } + + if (status[13] & 0x02) + card->sw_caps.hs_max_dtr = 50000000; + + memset(&cmd, 0, sizeof(struct mmc_command)); + + cmd.opcode = SD_SWITCH; + cmd.arg = 0x80FFFFF1; + cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC; + + memset(&data, 0, sizeof(struct mmc_data)); + + mmc_set_data_timeout(&data, card, 0); + + data.blksz = 64; + data.blocks = 1; + data.flags = MMC_DATA_READ; + data.sg = &sg; + data.sg_len = 1; + + memset(&mrq, 0, sizeof(struct mmc_request)); + + mrq.cmd = &cmd; + mrq.data = &data; + + sg_init_one(&sg, status, 64); + + mmc_wait_for_req(host, &mrq); + + if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE) { + mmc_card_set_dead(card); + continue; + } + + if ((status[16] & 0xF) != 1) { + printk(KERN_WARNING "%s: Problem switching card " + "into high-speed mode!\n", + mmc_hostname(host)); + continue; + } + + mmc_card_set_highspeed(card); + } + + kfree(status); + + mmc_deselect_cards(host); +} + static unsigned int mmc_calculate_clock(struct mmc_host *host) { struct mmc_card *card; @@ -1164,9 +1274,12 @@ static unsigned int mmc_calculate_clock(struct mmc_host *host) list_for_each_entry(card, &host->cards, node) if (!mmc_card_dead(card)) { - if (mmc_card_highspeed(card)) { + if (mmc_card_highspeed(card) && mmc_card_sd(card)) { + if (max_dtr > card->sw_caps.hs_max_dtr) + max_dtr = card->sw_caps.hs_max_dtr; + } else if (mmc_card_highspeed(card) && !mmc_card_sd(card)) { if (max_dtr > card->ext_csd.hs_max_dtr) - max_dtr = card->ext_csd.hs_max_dtr; + max_dtr = card->ext_csd.hs_max_dtr; } else if (max_dtr > card->csd.max_dtr) { max_dtr = card->csd.max_dtr; } @@ -1288,9 +1401,10 @@ static void mmc_setup(struct mmc_host *host) mmc_read_csds(host); - if (host->mode == MMC_MODE_SD) + if (host->mode == MMC_MODE_SD) { mmc_read_scrs(host); - else + mmc_read_switch_caps(host); + } else mmc_process_ext_csds(host); } diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h index ce25256f80d5..d0e6a5497614 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -50,6 +50,10 @@ struct sd_scr { #define SD_SCR_BUS_WIDTH_4 (1<<2) }; +struct sd_switch_caps { + unsigned int hs_max_dtr; +}; + struct mmc_host; /* @@ -66,7 +70,7 @@ struct mmc_card { #define MMC_STATE_BAD (1<<2) /* unrecognised device */ #define MMC_STATE_SDCARD (1<<3) /* is an SD card */ #define MMC_STATE_READONLY (1<<4) /* card is read-only */ -#define MMC_STATE_HIGHSPEED (1<<5) /* card is in mmc4 highspeed mode */ +#define MMC_STATE_HIGHSPEED (1<<5) /* card is in high speed mode */ u32 raw_cid[4]; /* raw card CID */ u32 raw_csd[4]; /* raw card CSD */ u32 raw_scr[2]; /* raw card SCR */ @@ -74,6 +78,7 @@ struct mmc_card { struct mmc_csd csd; /* card specific */ struct mmc_ext_csd ext_csd; /* mmc v4 extended card specific */ struct sd_scr scr; /* extra SD information */ + struct sd_switch_caps sw_caps; /* switch (CMD6) caps */ }; #define mmc_card_present(c) ((c)->state & MMC_STATE_PRESENT) diff --git a/include/linux/mmc/protocol.h b/include/linux/mmc/protocol.h index 45c51fd85786..2dce60c43f4b 100644 --- a/include/linux/mmc/protocol.h +++ b/include/linux/mmc/protocol.h @@ -82,6 +82,7 @@ /* class 8 */ /* This is basically the same command as for MMC with some quirks. */ #define SD_SEND_RELATIVE_ADDR 3 /* bcr R6 */ +#define SD_SWITCH 6 /* adtc [31:0] See below R1 */ /* Application commands */ #define SD_APP_SET_BUS_WIDTH 6 /* ac [1:0] bus width R1 */ @@ -100,6 +101,19 @@ * [02:00] Command Set */ +/* + * SD_SWITCH argument format: + * + * [31] Check (0) or switch (1) + * [30:24] Reserved (0) + * [23:20] Function group 6 + * [19:16] Function group 5 + * [15:12] Function group 4 + * [11:8] Function group 3 + * [7:4] Function group 2 + * [3:0] Function group 1 + */ + /* MMC status in R1 Type @@ -284,6 +298,14 @@ struct _mmc_csd { #define MMC_SWITCH_MODE_CLEAR_BITS 0x02 /* Clear bits which are 1 in value */ #define MMC_SWITCH_MODE_WRITE_BYTE 0x03 /* Set target to value */ +/* + * SCR field definitions + */ + +#define SCR_SPEC_VER_0 0 /* Implements system specification 1.0 - 1.01 */ +#define SCR_SPEC_VER_1 1 /* Implements system specification 1.10 */ +#define SCR_SPEC_VER_2 2 /* Implements system specification 2.00 */ + /* * SD bus widths */ -- 2.34.1