From patchwork Tue Jan 8 14:06:02 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Rudholm X-Patchwork-Id: 1946391 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 7F6E6DF23A for ; Tue, 8 Jan 2013 14:06:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756401Ab3AHOGs (ORCPT ); Tue, 8 Jan 2013 09:06:48 -0500 Received: from eu1sys200aog116.obsmtp.com ([207.126.144.141]:55016 "EHLO eu1sys200aog116.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756381Ab3AHOGs (ORCPT ); Tue, 8 Jan 2013 09:06:48 -0500 Received: from beta.dmz-us.st.com ([167.4.1.35]) (using TLSv1) by eu1sys200aob116.postini.com ([207.126.147.11]) with SMTP ID DSNKUOwn54ga4x7Ta1xYM/B3qRJ4BgsaqWv1@postini.com; Tue, 08 Jan 2013 14:06:47 UTC Received: from zeta.dmz-us.st.com (ns4.st.com [167.4.16.71]) by beta.dmz-us.st.com (STMicroelectronics) with ESMTP id 6971F45; Tue, 8 Jan 2013 14:05:42 +0000 (GMT) Received: from relay2.stm.gmessaging.net (unknown [10.230.100.18]) by zeta.dmz-us.st.com (STMicroelectronics) with ESMTP id 9CB6C70; Tue, 8 Jan 2013 08:35:24 +0000 (GMT) Received: from exdcvycastm022.EQ1STM.local (alteon-source-exch [10.230.100.61]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (Client CN "exdcvycastm022", Issuer "exdcvycastm022" (not verified)) by relay2.stm.gmessaging.net (Postfix) with ESMTPS id 750AAA8072; Tue, 8 Jan 2013 15:06:18 +0100 (CET) Received: from steludxu1610.lud.stericsson.com (10.230.100.153) by smtp.stericsson.com (10.230.100.30) with Microsoft SMTP Server (TLS) id 8.3.83.0; Tue, 8 Jan 2013 15:06:23 +0100 From: Johan Rudholm To: , Chris Ball Cc: Per Forlin , Ulf Hansson , Fredrik Soderstedt , Kevin Liu , Philip Rakity , Daniel Drake , Aaron , Subhash Jadavani , Johan Rudholm , Kevin Liu Subject: [PATCH v5 4/4] mmc: core: Fixup signal voltage switch Date: Tue, 8 Jan 2013 15:06:02 +0100 Message-ID: <1357653962-10887-5-git-send-email-johan.rudholm@stericsson.com> X-Mailer: git-send-email 1.7.10 In-Reply-To: <1357653962-10887-1-git-send-email-johan.rudholm@stericsson.com> References: <1357653962-10887-1-git-send-email-johan.rudholm@stericsson.com> MIME-Version: 1.0 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org When switching SD and SDIO cards from 3.3V to 1.8V signal levels, the clock should be gated for 5 ms during the step. After enabling the clock, the host should wait for at least 1 ms before checking for failure. Failure by the card to switch is indicated by dat[0:3] being pulled low. The host should check for this condition and power-cycle the card if failure is indicated. Add a retry mechanism for the SDIO case. If the voltage switch fails repeatedly, give up and continue the initialization using the original voltage. This patch places a couple of requirements on the host driver: 1) mmc_set_ios with ios.clock = 0 must gate the clock 2) mmc_power_off must actually cut the power to the card 3) The card_busy host_ops member must be implemented if these requirements are not fulfilled, the 1.8V signal voltage switch will still be attempted but may not be successful. Signed-off-by: Johan Rudholm Signed-off-by: Kevin Liu Signed-off-by: Ulf Hansson --- drivers/mmc/core/core.c | 83 +++++++++++++++++++++++++++++++++++++++++------ drivers/mmc/core/sd.c | 21 +++++++++--- drivers/mmc/core/sdio.c | 20 ++++++++++-- 3 files changed, 107 insertions(+), 17 deletions(-) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 03db641..bf10cf4 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -1242,6 +1242,7 @@ int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage) { struct mmc_command cmd = {0}; int err = 0; + u32 clock; BUG_ON(!host); @@ -1249,20 +1250,82 @@ int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage) * Send CMD11 only if the request is to switch the card to * 1.8V signalling. */ - if (signal_voltage != MMC_SIGNAL_VOLTAGE_330) { - cmd.opcode = SD_SWITCH_VOLTAGE; - cmd.arg = 0; - cmd.flags = MMC_RSP_R1 | MMC_CMD_AC; + if (signal_voltage == MMC_SIGNAL_VOLTAGE_330) + return __mmc_set_signal_voltage(host, signal_voltage); - err = mmc_wait_for_cmd(host, &cmd, 0); - if (err) - return err; + /* + * If we cannot switch voltages, return failure so the caller + * can continue without UHS mode + */ + if (!host->ops->start_signal_voltage_switch) + return -EPERM; + if (!host->ops->card_busy) + pr_warning("%s: cannot verify signal voltage switch\n", + mmc_hostname(host)); + + cmd.opcode = SD_SWITCH_VOLTAGE; + cmd.arg = 0; + cmd.flags = MMC_RSP_R1 | MMC_CMD_AC; + + err = mmc_wait_for_cmd(host, &cmd, 0); + if (err) + return err; - if (!mmc_host_is_spi(host) && (cmd.resp[0] & R1_ERROR)) - return -EIO; + if (!mmc_host_is_spi(host) && (cmd.resp[0] & R1_ERROR)) + return -EIO; + + mmc_host_clk_hold(host); + /* + * The card should drive cmd and dat[0:3] low immediately + * after the response of cmd11, but wait 1 ms to be sure + */ + mmc_delay(1); + if (host->ops->card_busy && !host->ops->card_busy(host)) { + err = -EAGAIN; + goto power_cycle; } + /* + * During a signal voltage level switch, the clock must be gated + * for 5 ms according to the SD spec + */ + clock = host->ios.clock; + host->ios.clock = 0; + mmc_set_ios(host); - return __mmc_set_signal_voltage(host, signal_voltage); + if (__mmc_set_signal_voltage(host, signal_voltage)) { + /* + * Voltages may not have been switched, but we've already + * sent CMD11, so a power cycle is required anyway + */ + err = -EAGAIN; + goto power_cycle; + } + + /* Keep clock gated for at least 5 ms */ + mmc_delay(5); + host->ios.clock = clock; + mmc_set_ios(host); + + /* Wait for at least 1 ms according to spec */ + mmc_delay(1); + + /* + * Failure to switch is indicated by the card holding + * dat[0:3] low + */ + if (host->ops->card_busy && host->ops->card_busy(host)) + err = -EAGAIN; + +power_cycle: + if (err) { + pr_debug("%s: Signal voltage switch failed, " + "power cycling card\n", mmc_hostname(host)); + mmc_power_cycle(host); + } + + mmc_host_clk_release(host); + + return err; } /* diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index 0cc1b26..f5729b0 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -713,6 +713,14 @@ int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid, u32 *rocr) { int err; u32 max_current; + int retries = 10; + +try_again: + if (!retries) { + ocr &= ~SD_OCR_S18R; + pr_warning("%s: Skipping voltage switch\n", + mmc_hostname(host)); + } /* * Since we're changing the OCR value, we seem to @@ -734,9 +742,10 @@ int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid, u32 *rocr) /* * If the host supports one of UHS-I modes, request the card - * to switch to 1.8V signaling level. + * to switch to 1.8V signaling level. If the card has failed + * repeatedly to switch however, skip this. */ - if (host->caps & (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 | + if (retries && host->caps & (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 | MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 | MMC_CAP_UHS_DDR50)) ocr |= SD_OCR_S18R; @@ -748,7 +757,6 @@ int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid, u32 *rocr) if (max_current > 150) ocr |= SD_OCR_XPC; -try_again: err = mmc_send_app_op_cond(host, ocr, rocr); if (err) return err; @@ -760,8 +768,11 @@ try_again: if (!mmc_host_is_spi(host) && rocr && ((*rocr & 0x41000000) == 0x41000000)) { err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180); - if (err) { - ocr &= ~SD_OCR_S18R; + if (err == -EAGAIN) { + retries--; + goto try_again; + } else if (err) { + retries = 0; goto try_again; } } diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c index 0c84e0f..494569b 100644 --- a/drivers/mmc/core/sdio.c +++ b/drivers/mmc/core/sdio.c @@ -583,10 +583,19 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr, { struct mmc_card *card; int err; + int retries = 10; BUG_ON(!host); WARN_ON(!host->claimed); +try_again: + if (!retries) { + pr_warning("%s: Skipping voltage switch\n", + mmc_hostname(host)); + ocr &= ~R4_18V_PRESENT; + host->ocr &= ~R4_18V_PRESENT; + } + /* * Inform the card of the voltage */ @@ -645,13 +654,20 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr, * systems that claim 1.8v signalling in fact do not support * it. */ - if ((ocr & R4_18V_PRESENT) && + if (!powered_resume && (ocr & R4_18V_PRESENT) && (host->caps & (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 | MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 | MMC_CAP_UHS_DDR50))) { err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180); - if (err) { + if (err == -EAGAIN) { + sdio_reset(host); + mmc_go_idle(host); + mmc_send_if_cond(host, host->ocr_avail); + mmc_remove_card(card); + retries--; + goto try_again; + } else if (err) { ocr &= ~R4_18V_PRESENT; host->ocr &= ~R4_18V_PRESENT; }