From patchwork Tue May 19 03:06:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Y.b. Lu" X-Patchwork-Id: 245965 List-Id: U-Boot discussion From: yangbo.lu at nxp.com (Yangbo Lu) Date: Tue, 19 May 2020 11:06:43 +0800 Subject: [v2, 1/2] mmc: fsl_esdhc: read register once for card inserted status Message-ID: <20200519030644.11290-1-yangbo.lu@nxp.com> No need to poll register for card inserted status. Signed-off-by: Yangbo Lu Acked-by: Peng Fan --- Changes for v2: - Updated copyright. --- drivers/mmc/fsl_esdhc.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c index 386781d..02d9230 100644 --- a/drivers/mmc/fsl_esdhc.c +++ b/drivers/mmc/fsl_esdhc.c @@ -1,7 +1,7 @@ // SPDX-License-Identifier: GPL-2.0+ /* * Copyright 2007, 2010-2011 Freescale Semiconductor, Inc - * Copyright 2019 NXP Semiconductors + * Copyright 2019-2020 NXP * Andy Fleming * * Based vaguely on the pxa mmc code: @@ -627,16 +627,15 @@ static int esdhc_init_common(struct fsl_esdhc_priv *priv, struct mmc *mmc) static int esdhc_getcd_common(struct fsl_esdhc_priv *priv) { struct fsl_esdhc *regs = priv->esdhc_regs; - int timeout = 1000; #ifdef CONFIG_ESDHC_DETECT_QUIRK if (CONFIG_ESDHC_DETECT_QUIRK) return 1; #endif - while (!(esdhc_read32(®s->prsstat) & PRSSTAT_CINS) && --timeout) - udelay(1000); + if (esdhc_read32(®s->prsstat) & PRSSTAT_CINS) + return 1; - return timeout > 0; + return 0; } static void fsl_esdhc_get_cfg_common(struct fsl_esdhc_priv *priv, From patchwork Tue May 19 03:06:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Y.b. Lu" X-Patchwork-Id: 245964 List-Id: U-Boot discussion From: yangbo.lu at nxp.com (Yangbo Lu) Date: Tue, 19 May 2020 11:06:44 +0800 Subject: [v2, 2/2] mmc: fsl_esdhc: workaround for hardware 3.3v IO reliability issue In-Reply-To: <20200519030644.11290-1-yangbo.lu@nxp.com> References: <20200519030644.11290-1-yangbo.lu@nxp.com> Message-ID: <20200519030644.11290-2-yangbo.lu@nxp.com> When eSDHC operates at 3.3v, damage can accumulate in an internal level shifter at a higher than expected rate. The faster the interface runs, the more damage accumulates. This issue now is found on LX2160A eSDHC1 for only SD card. The hardware workaround is recommended to use an on-board level shifter that is 1.8v on SoC side and 3.3v on SD card side. For boards without hardware workaround, this option could be enabled, ensuring 1.8v IO voltage and disabling eSDHC if no card. This option assumes no hotplug, and u-boot has to make all the way to to linux to use 1.8v UHS-I speed mode if has card. If you do not want the workaround for better user experience, of course you can choose to not select it running eSDHC in unsafe mode. Signed-off-by: Yangbo Lu Acked-by: Peng Fan --- Changes for v2: - Updated copyright. --- drivers/mmc/Kconfig | 15 +++++++++++++++ drivers/mmc/fsl_esdhc.c | 38 ++++++++++++++++++++++++++++++++++++-- include/fsl_esdhc.h | 2 ++ 3 files changed, 53 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig index 3c4f057..8f56572 100644 --- a/drivers/mmc/Kconfig +++ b/drivers/mmc/Kconfig @@ -727,6 +727,21 @@ config FSL_ESDHC This selects support for the eSDHC (Enhanced Secure Digital Host Controller) found on numerous Freescale/NXP SoCs. +config FSL_ESDHC_33V_IO_RELIABILITY_WORKAROUND + bool "enable eSDHC workaround for 3.3v IO reliability issue" + depends on FSL_ESDHC && DM_MMC + default n + help + When eSDHC operates at 3.3v, damage can accumulate in an internal + level shifter at a higher than expected rate. The faster the interface + runs, the more damage accumulates. This issue now is found on LX2160A + eSDHC1 for only SD card. The hardware workaround is recommended to use + an on-board level shifter that is 1.8v on SoC side and 3.3v on SD card + side. For boards without hardware workaround, this option could be + enabled, ensuring 1.8v IO voltage and disabling eSDHC if no card. + This option assumes no hotplug, and u-boot has to make all the way to + to linux to use 1.8v UHS-I speed mode if has card. + config FSL_ESDHC_IMX bool "Freescale/NXP i.MX eSDHC controller support" help diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c index 02d9230..98da568 100644 --- a/drivers/mmc/fsl_esdhc.c +++ b/drivers/mmc/fsl_esdhc.c @@ -720,13 +720,38 @@ __weak int esdhc_status_fixup(void *blob, const char *compat) return 0; } +#ifdef CONFIG_FSL_ESDHC_33V_IO_RELIABILITY_WORKAROUND +static int fsl_esdhc_get_cd(struct udevice *dev); + +static void esdhc_disable_for_no_card(void *blob) +{ + struct udevice *dev; + + for (uclass_first_device(UCLASS_MMC, &dev); + dev; + uclass_next_device(&dev)) { + char esdhc_path[50]; + + if (fsl_esdhc_get_cd(dev)) + continue; + + snprintf(esdhc_path, sizeof(esdhc_path), "/soc/esdhc@%lx", + (unsigned long)dev_read_addr(dev)); + do_fixup_by_path(blob, esdhc_path, "status", "disabled", + sizeof("disabled"), 1); + } +} +#endif + void fdt_fixup_esdhc(void *blob, bd_t *bd) { const char *compat = "fsl,esdhc"; if (esdhc_status_fixup(blob, compat)) return; - +#ifdef CONFIG_FSL_ESDHC_33V_IO_RELIABILITY_WORKAROUND + esdhc_disable_for_no_card(blob); +#endif do_fixup_by_compat_u32(blob, compat, "clock-frequency", gd->arch.sdhc_clk, 1); } @@ -845,6 +870,7 @@ static int fsl_esdhc_probe(struct udevice *dev) struct fsl_esdhc_priv *priv = dev_get_priv(dev); fdt_addr_t addr; struct mmc *mmc; + int ret; addr = dev_read_addr(dev); if (addr == FDT_ADDR_T_NONE) @@ -878,7 +904,15 @@ static int fsl_esdhc_probe(struct udevice *dev) upriv->mmc = mmc; - return esdhc_init_common(priv, mmc); + ret = esdhc_init_common(priv, mmc); + if (ret) + return ret; + +#ifdef CONFIG_FSL_ESDHC_33V_IO_RELIABILITY_WORKAROUND + if (!fsl_esdhc_get_cd(dev)) + esdhc_setbits32(&priv->esdhc_regs->proctl, PROCTL_VOLT_SEL); +#endif + return 0; } static int fsl_esdhc_get_cd(struct udevice *dev) diff --git a/include/fsl_esdhc.h b/include/fsl_esdhc.h index 8e8cd2c..e148eaa 100644 --- a/include/fsl_esdhc.h +++ b/include/fsl_esdhc.h @@ -4,6 +4,7 @@ *------------------------------------------------------------------- * * Copyright 2007-2008,2010-2011 Freescale Semiconductor, Inc + * Copyright 2020 NXP */ #ifndef __FSL_ESDHC_H__ @@ -98,6 +99,7 @@ #define PROCTL_DTW_4 0x00000002 #define PROCTL_DTW_8 0x00000004 #define PROCTL_D3CD 0x00000008 +#define PROCTL_VOLT_SEL 0x00000400 #define CMDARG 0x0002e008