From mboxrd@z Thu Jan 1 00:00:00 1970 From: Seungwon Jeon Subject: [PATCH v2 4/5] mmc: rework selection of bus speed mode Date: Fri, 07 Mar 2014 23:36:35 +0900 Message-ID: <003e01cf3a12$a416e560$ec44b020$%jun@samsung.com> References: <1383653403-10049-1-git-send-email-ulf.hansson@linaro.org> <006b01cf2a59$a203d5d0$e60b8170$%jun@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mailout3.samsung.com ([203.254.224.33]:18617 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752671AbaCGOgh (ORCPT ); Fri, 7 Mar 2014 09:36:37 -0500 Received: from epcpsbgr4.samsung.com (u144.gpu120.samsung.co.kr [203.254.230.144]) by mailout3.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0N2200LJ9LWZJN90@mailout3.samsung.com> for linux-mmc@vger.kernel.org; Fri, 07 Mar 2014 23:36:35 +0900 (KST) In-reply-to: <006b01cf2a59$a203d5d0$e60b8170$%jun@samsung.com> Content-language: ko Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: linux-mmc@vger.kernel.org Cc: 'Chris Ball' , 'Ulf Hansson' , 'Jaehoon Chung' , 'Jackey Shen' , 'Alim Akhtar' Current implementation for bus speed mode selection is too complicated. This patch is to simplify the codes and remove some duplicate parts. The following changes are including: * Adds functions for each mode selection(HS, HS-DDR, HS200 and etc) * Rearranged the mode selection sequence with supported device type * Adds maximum speed for HS200 mode(hs200_max_dtr) * Adds field definition for HS_TIMING of EXT_CSD Signed-off-by: Seungwon Jeon --- Changes in v2: Cleaned up some unnecessary codes. drivers/mmc/core/debugfs.c | 2 +- drivers/mmc/core/mmc.c | 432 ++++++++++++++++++++++++-------------------- include/linux/mmc/card.h | 1 + include/linux/mmc/mmc.h | 4 + 4 files changed, 239 insertions(+), 200 deletions(-) diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c index 509229b..1f730db 100644 --- a/drivers/mmc/core/debugfs.c +++ b/drivers/mmc/core/debugfs.c @@ -139,7 +139,7 @@ static int mmc_ios_show(struct seq_file *s, void *data) str = "mmc DDR52"; break; case MMC_TIMING_MMC_HS200: - str = "mmc high-speed SDR200"; + str = "mmc HS200"; break; default: str = "invalid"; diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 88ff217..e356a54 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -242,7 +242,7 @@ static void mmc_select_card_type(struct mmc_card *card) struct mmc_host *host = card->host; u8 card_type = card->ext_csd.raw_card_type & EXT_CSD_CARD_TYPE_MASK; u32 caps = host->caps, caps2 = host->caps2; - unsigned int hs_max_dtr = 0; + unsigned int hs_max_dtr = 0, hs200_max_dtr = 0; unsigned int avail_type = 0; if (caps & MMC_CAP_MMC_HIGHSPEED && @@ -271,17 +271,18 @@ static void mmc_select_card_type(struct mmc_card *card) if (caps2 & MMC_CAP2_HS200_1_8V_SDR && card_type & EXT_CSD_CARD_TYPE_HS200_1_8V) { - hs_max_dtr = MMC_HS200_MAX_DTR; + hs200_max_dtr = MMC_HS200_MAX_DTR; avail_type |= EXT_CSD_CARD_TYPE_HS200_1_8V; } if (caps2 & MMC_CAP2_HS200_1_2V_SDR && card_type & EXT_CSD_CARD_TYPE_HS200_1_2V) { - hs_max_dtr = MMC_HS200_MAX_DTR; + hs200_max_dtr = MMC_HS200_MAX_DTR; avail_type |= EXT_CSD_CARD_TYPE_HS200_1_2V; } card->ext_csd.hs_max_dtr = hs_max_dtr; + card->ext_csd.hs200_max_dtr = hs200_max_dtr; card->mmc_avail_type = avail_type; } @@ -838,37 +839,46 @@ static int mmc_select_powerclass(struct mmc_card *card) } /* - * Selects the desired buswidth and switch to the HS200 mode - * if bus width set without error + * Set the bus speed for the selected speed mode. */ -static int mmc_select_hs200(struct mmc_card *card) +static void mmc_set_bus_speed(struct mmc_card *card) +{ + unsigned int max_dtr = (unsigned int)-1; + + if (mmc_card_hs200(card) && max_dtr > card->ext_csd.hs200_max_dtr) + max_dtr = card->ext_csd.hs200_max_dtr; + else if (mmc_card_hs(card) && 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; + + mmc_set_clock(card->host, max_dtr); +} + +/* + * Select the bus width amoung 4-bit and 8-bit(SDR). + * If the bus width is changed successfully, return the slected width value. + * Zero is returned instead of error value if the wide width is not supported. + */ +static int mmc_select_bus_width(struct mmc_card *card) { - int idx, err = -EINVAL; - struct mmc_host *host; static unsigned ext_csd_bits[] = { - EXT_CSD_BUS_WIDTH_4, EXT_CSD_BUS_WIDTH_8, + EXT_CSD_BUS_WIDTH_4, }; static unsigned bus_widths[] = { - MMC_BUS_WIDTH_4, MMC_BUS_WIDTH_8, + MMC_BUS_WIDTH_4, }; + struct mmc_host *host = card->host; + unsigned idx, bus_width = 0; + int err = 0; - BUG_ON(!card); - - host = card->host; - - if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_2V) - err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120); - - if (err && card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_8V) - err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180); - - /* If fails try again during next card power cycle */ - if (err) - goto err; + if ((card->csd.mmca_vsn < CSD_SPEC_VER_4) && + !(host->caps & (MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA))) + return 0; - idx = (host->caps & MMC_CAP_8_BIT_DATA) ? 1 : 0; + idx = (host->caps & MMC_CAP_8_BIT_DATA) ? 0 : 1; /* * Unlike SD, MMC cards dont have a configuration register to notify @@ -876,8 +886,7 @@ static int mmc_select_hs200(struct mmc_card *card) * the supported bus width or compare the ext csd values of current * bus width and ext csd values of 1 bit mode read earlier. */ - for (; idx >= 0; idx--) { - + for (; idx < ARRAY_SIZE(bus_widths); idx++) { /* * Host is capable of 8bit transfer, then switch * the device to work in 8bit transfer mode. If the @@ -892,27 +901,203 @@ static int mmc_select_hs200(struct mmc_card *card) if (err) continue; - mmc_set_bus_width(card->host, bus_widths[idx]); + bus_width = bus_widths[idx]; + mmc_set_bus_width(host, bus_width); + /* + * If controller can't handle bus width test, + * compare ext_csd previously read in 1 bit mode + * against ext_csd at new bus width + */ if (!(host->caps & MMC_CAP_BUS_WIDTH_TEST)) - err = mmc_compare_ext_csds(card, bus_widths[idx]); + err = mmc_compare_ext_csds(card, bus_width); else - err = mmc_bus_test(card, bus_widths[idx]); - if (!err) + err = mmc_bus_test(card, bus_width); + + if (!err) { + err = bus_width; break; + } else { + pr_warn("%s: switch to bus width %d failed\n", + mmc_hostname(host), ext_csd_bits[idx]); + } } - /* switch to HS200 mode if bus width set successfully */ + return err; +} + +/* + * Switch to the high-speed mode + */ +static int mmc_select_hs(struct mmc_card *card) +{ + int err; + + err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, + EXT_CSD_HS_TIMING, EXT_CSD_TIMING_HS, + card->ext_csd.generic_cmd6_time, + true, true, true); if (!err) + mmc_set_timing(card->host, MMC_TIMING_MMC_HS); + + return err; +} + +/* + * Activate wide bus and DDR if supported. + */ +static int mmc_select_hs_ddr(struct mmc_card *card) +{ + struct mmc_host *host = card->host; + u32 bus_width, ext_csd_bits; + int err = 0, ddr; + + ddr = mmc_snoop_ddr(card); + if (!(ddr & EXT_CSD_CARD_TYPE_DDR_52)) + return 0; + + bus_width = host->ios.bus_width; + if (bus_width == MMC_BUS_WIDTH_1) + return 0; + + ext_csd_bits = (bus_width == MMC_BUS_WIDTH_8) ? + EXT_CSD_DDR_BUS_WIDTH_8 : EXT_CSD_DDR_BUS_WIDTH_4; + + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, + EXT_CSD_BUS_WIDTH, + ext_csd_bits, + card->ext_csd.generic_cmd6_time); + if (err) { + pr_warn("%s: switch to bus width %d ddr failed\n", + mmc_hostname(host), 1 << bus_width); + return err; + } + + /* + * eMMC cards can support 3.3V to 1.2V i/o (vccq) + * signaling. + * + * EXT_CSD_CARD_TYPE_DDR_1_8V means 3.3V or 1.8V vccq. + * + * 1.8V vccq at 3.3V core voltage (vcc) is not required + * in the JEDEC spec for DDR. + * + * Do not force change in vccq since we are obviously + * working and no change to vccq is needed. + * + * WARNING: eMMC rules are NOT the same as SD DDR + */ + if (ddr & EXT_CSD_CARD_TYPE_DDR_1_2V) { + err = __mmc_set_signal_voltage(host, + MMC_SIGNAL_VOLTAGE_120); + if (err) + return err; + } + + mmc_set_timing(host, MMC_TIMING_MMC_DDR52); + + return err; +} + +/* + * For device supporting HS200 mode, the following sequence + * should be done before executing the tuning process. + * 1. set the desired bus width(4-bit or 8-bit, 1-bit is not supported) + * 2. switch to HS200 mode + * 3. set the clock to > 52Mhz and <=200MHz + */ +static int mmc_select_hs200(struct mmc_card *card) +{ + struct mmc_host *host = card->host; + int err = -EINVAL; + + if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_2V) + err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120); + + if (err && card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_8V) + err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180); + + /* If fails try again during next card power cycle */ + if (err) + goto err; + + /* + * Set the bus width(4 or 8) with host's support and + * switch to HS200 mode if bus width is set successfully. + */ + err = mmc_select_bus_width(card); + if (!IS_ERR_VALUE(err)) { err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, - EXT_CSD_HS_TIMING, 2, - card->ext_csd.generic_cmd6_time, - true, true, true); + EXT_CSD_HS_TIMING, EXT_CSD_TIMING_HS200, + card->ext_csd.generic_cmd6_time, + true, true, true); + if (!err) + mmc_set_timing(host, MMC_TIMING_MMC_HS200); + } err: return err; } /* + * Activate High Speed or HS200 mode if supported. + */ +static int mmc_select_timing(struct mmc_card *card) +{ + int err = 0; + + if ((card->csd.mmca_vsn < CSD_SPEC_VER_4 && + card->ext_csd.hs_max_dtr == 0)) + goto bus_speed; + + if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200) + err = mmc_select_hs200(card); + else if(card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS) + err = mmc_select_hs(card); + + if (err && err != -EBADMSG) + return err; + + if (err) { + pr_warn("%s: switch to %s failed\n", + mmc_card_hs(card) ? "high-speed" : + (mmc_card_hs200(card) ? "hs200" : ""), + mmc_hostname(card->host)); + err = 0; + } + +bus_speed: + /* + * Set the bus speed to the selected bus timing. + * If timing is not selected, backward compatible is the default. + */ + mmc_set_bus_speed(card); + return err; +} + +/* + * Execute tuning sequence to seek the proper bus operating + * conditions for HS200, which sends CMD21 to the device. + */ +static int mmc_hs200_tuning(struct mmc_card *card) +{ + struct mmc_host *host = card->host; + int err = 0; + + if (host->ops->execute_tuning) { + mmc_host_clk_hold(host); + err = host->ops->execute_tuning(host, + MMC_SEND_TUNING_BLOCK_HS200); + mmc_host_clk_release(host); + + if (err) + pr_warn("%s: tuning execution failed\n", + mmc_hostname(host)); + } + + return err; +} + +/* * Handle the detection and initialisation of a card. * * In the case of a resume, "oldcard" will contain the card @@ -922,9 +1107,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, struct mmc_card *oldcard) { struct mmc_card *card; - int err, ddr = 0; + int err; u32 cid[4]; - unsigned int max_dtr; u32 rocr; u8 *ext_csd = NULL; @@ -1116,173 +1300,23 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, } /* - * Activate high speed (if supported) - */ - if (card->ext_csd.hs_max_dtr != 0) { - err = 0; - if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200) - err = mmc_select_hs200(card); - else if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS) - err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, - EXT_CSD_HS_TIMING, 1, - card->ext_csd.generic_cmd6_time, - true, true, true); - - if (err && err != -EBADMSG) - goto free_card; - - if (err) { - pr_warning("%s: switch to highspeed failed\n", - mmc_hostname(card->host)); - err = 0; - } else { - if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200) - mmc_set_timing(card->host, - MMC_TIMING_MMC_HS200); - else - mmc_set_timing(card->host, MMC_TIMING_MMC_HS); - } - } - - /* - * Compute bus speed. - */ - max_dtr = (unsigned int)-1; - - if (mmc_card_hs(card) || mmc_card_hs200(card)) { - if (max_dtr > card->ext_csd.hs_max_dtr) - max_dtr = card->ext_csd.hs_max_dtr; - if (mmc_card_hs(card) && (max_dtr > 52000000)) - max_dtr = 52000000; - } else if (max_dtr > card->csd.max_dtr) { - max_dtr = card->csd.max_dtr; - } - - mmc_set_clock(host, max_dtr); - - /* - * Indicate DDR mode (if supported). + * Select timing interface */ - if (mmc_card_hs(card)) - ddr = mmc_snoop_ddr(card); + err = mmc_select_timing(card); + if (err) + goto free_card; - /* - * Indicate HS200 SDR mode (if supported). - */ if (mmc_card_hs200(card)) { - u32 ext_csd_bits; - u32 bus_width = card->host->ios.bus_width; - - /* - * For devices supporting HS200 mode, the bus width has - * to be set before executing the tuning function. If - * set before tuning, then device will respond with CRC - * errors for responses on CMD line. So for HS200 the - * sequence will be - * 1. set bus width 4bit / 8 bit (1 bit not supported) - * 2. switch to HS200 mode - * 3. set the clock to > 52Mhz <=200MHz and - * 4. execute tuning for HS200 - */ - if (card->host->ops->execute_tuning) { - mmc_host_clk_hold(card->host); - err = card->host->ops->execute_tuning(card->host, - MMC_SEND_TUNING_BLOCK_HS200); - mmc_host_clk_release(card->host); - } - if (err) { - pr_warning("%s: tuning execution failed\n", - mmc_hostname(card->host)); + err = mmc_hs200_tuning(card); + if (err) goto err; - } - - ext_csd_bits = (bus_width == MMC_BUS_WIDTH_8) ? - EXT_CSD_BUS_WIDTH_8 : EXT_CSD_BUS_WIDTH_4; - } - - /* - * Activate wide bus and DDR (if supported). - */ - if (!mmc_card_hs200(card) && - (card->csd.mmca_vsn >= CSD_SPEC_VER_4) && - (host->caps & (MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA))) { - static unsigned ext_csd_bits[][2] = { - { EXT_CSD_BUS_WIDTH_8, EXT_CSD_DDR_BUS_WIDTH_8 }, - { EXT_CSD_BUS_WIDTH_4, EXT_CSD_DDR_BUS_WIDTH_4 }, - { EXT_CSD_BUS_WIDTH_1, EXT_CSD_BUS_WIDTH_1 }, - }; - static unsigned bus_widths[] = { - MMC_BUS_WIDTH_8, - MMC_BUS_WIDTH_4, - MMC_BUS_WIDTH_1 - }; - unsigned idx, bus_width = 0; - - if (host->caps & MMC_CAP_8_BIT_DATA) - idx = 0; - else - idx = 1; - for (; idx < ARRAY_SIZE(bus_widths); idx++) { - bus_width = bus_widths[idx]; - if (bus_width == MMC_BUS_WIDTH_1) - ddr = 0; /* no DDR for 1-bit width */ - - err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, - EXT_CSD_BUS_WIDTH, - ext_csd_bits[idx][0], - card->ext_csd.generic_cmd6_time); - if (!err) { - mmc_set_bus_width(card->host, bus_width); - - /* - * If controller can't handle bus width test, - * compare ext_csd previously read in 1 bit mode - * against ext_csd at new bus width - */ - if (!(host->caps & MMC_CAP_BUS_WIDTH_TEST)) - err = mmc_compare_ext_csds(card, - bus_width); - else - err = mmc_bus_test(card, bus_width); - if (!err) - break; - } - } - - if (!err && ddr) { - err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, - EXT_CSD_BUS_WIDTH, - ext_csd_bits[idx][1], - card->ext_csd.generic_cmd6_time); - } - if (err) { - pr_warning("%s: switch to bus width %d ddr %d " - "failed\n", mmc_hostname(card->host), - 1 << bus_width, ddr); - goto free_card; - } else if (ddr) { - /* - * eMMC cards can support 3.3V to 1.2V i/o (vccq) - * signaling. - * - * EXT_CSD_CARD_TYPE_DDR_1_8V means 3.3V or 1.8V vccq. - * - * 1.8V vccq at 3.3V core voltage (vcc) is not required - * in the JEDEC spec for DDR. - * - * Do not force change in vccq since we are obviously - * working and no change to vccq is needed. - * - * WARNING: eMMC rules are NOT the same as SD DDR - */ - if (ddr & EXT_CSD_CARD_TYPE_DDR_1_2V) { - err = __mmc_set_signal_voltage(host, - MMC_SIGNAL_VOLTAGE_120); - if (err) - goto err; - } - mmc_set_timing(card->host, MMC_TIMING_MMC_DDR52); - mmc_set_bus_width(card->host, bus_width); + } else if (mmc_card_hs(card)) { + /* Select the desired bus width optionally */ + err = mmc_select_bus_width(card); + if (!IS_ERR_VALUE(err)) { + err = mmc_select_hs_ddr(card); + if (err) + goto err; } } diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h index c232b10..def6814 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -63,6 +63,7 @@ struct mmc_ext_csd { unsigned int power_off_longtime; /* Units: ms */ u8 power_off_notification; /* state */ unsigned int hs_max_dtr; + unsigned int hs200_max_dtr; #define MMC_HIGH_26_MAX_DTR 26000000 #define MMC_HIGH_52_MAX_DTR 52000000 #define MMC_HIGH_DDR_MAX_DTR 52000000 diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h index f734c0c..f429f13 100644 --- a/include/linux/mmc/mmc.h +++ b/include/linux/mmc/mmc.h @@ -377,6 +377,10 @@ struct _mmc_csd { #define EXT_CSD_DDR_BUS_WIDTH_4 5 /* Card is in 4 bit DDR mode */ #define EXT_CSD_DDR_BUS_WIDTH_8 6 /* Card is in 8 bit DDR mode */ +#define EXT_CSD_TIMING_BC 0 /* Backwards compatility */ +#define EXT_CSD_TIMING_HS 1 /* High speed */ +#define EXT_CSD_TIMING_HS200 2 /* HS200 */ + #define EXT_CSD_SEC_ER_EN BIT(0) #define EXT_CSD_SEC_BD_BLK_EN BIT(2) #define EXT_CSD_SEC_GB_CL_EN BIT(4) -- 1.7.0.4