From 11a219606a9bc7f1fcdb4fde285100fd8a601d0d Mon Sep 17 00:00:00 2001 From: Takeshi Saito Date: Tue, 17 Dec 2019 12:40:31 +0100 Subject: [PATCH] mmc: renesas_sdhi: Add manual correction This patch adds a manual correction mechanism for SDHI. Currently, SDHI uses automatic TAP position correction. However, TAP position can also be corrected manually via correction error status flags. Signed-off-by: Takeshi Saito Reviewed-by: Yoshihiro Shimoda Signed-off-by: Wolfram Sang Link: https://lore.kernel.org/r/20191217114034.13290-3-wsa+renesas@sang-engineering.com Signed-off-by: Ulf Hansson --- drivers/mmc/host/renesas_sdhi.h | 1 + drivers/mmc/host/renesas_sdhi_core.c | 61 +++++++++++++++++++++++----- 2 files changed, 52 insertions(+), 10 deletions(-) diff --git a/drivers/mmc/host/renesas_sdhi.h b/drivers/mmc/host/renesas_sdhi.h index f524251d5113..11a0b2bca3aa 100644 --- a/drivers/mmc/host/renesas_sdhi.h +++ b/drivers/mmc/host/renesas_sdhi.h @@ -57,6 +57,7 @@ struct renesas_sdhi { void __iomem *scc_ctl; u32 scc_tappos; u32 scc_tappos_hs400; + bool doing_tune; }; #define host_to_priv(host) \ diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c index 519d91ae3373..6cedc0a10593 100644 --- a/drivers/mmc/host/renesas_sdhi_core.c +++ b/drivers/mmc/host/renesas_sdhi_core.c @@ -263,6 +263,8 @@ static int renesas_sdhi_start_signal_voltage_switch(struct mmc_host *mmc, #define SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN BIT(0) /* Definitions for values the SH_MOBILE_SDHI_SCC_RVSREQ register */ #define SH_MOBILE_SDHI_SCC_RVSREQ_RVSERR BIT(2) +#define SH_MOBILE_SDHI_SCC_RVSREQ_REQTAPUP BIT(1) +#define SH_MOBILE_SDHI_SCC_RVSREQ_REQTAPDOWN BIT(0) /* Definitions for values the SH_MOBILE_SDHI_SCC_TMPPORT2 register */ #define SH_MOBILE_SDHI_SCC_TMPPORT2_HS400OSEL BIT(4) #define SH_MOBILE_SDHI_SCC_TMPPORT2_HS400EN BIT(31) @@ -321,6 +323,8 @@ static void renesas_sdhi_prepare_tuning(struct tmio_mmc_host *host, { struct renesas_sdhi *priv = host_to_priv(host); + priv->doing_tune = true; + /* Set sampling clock position */ sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TAPSET, tap); } @@ -426,6 +430,8 @@ static int renesas_sdhi_select_tuning(struct tmio_mmc_host *host) unsigned long ntap; /* temporary counter of tuning success */ unsigned long i; + priv->doing_tune = false; + /* Clear SCC_RVSREQ */ sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ, 0); @@ -485,6 +491,47 @@ static int renesas_sdhi_select_tuning(struct tmio_mmc_host *host) return 0; } +static bool renesas_sdhi_manual_correction(struct tmio_mmc_host *host, bool use_4tap) +{ + struct renesas_sdhi *priv = host_to_priv(host); + u32 val; + + val = sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ); + if (!val) + return false; + + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ, 0); + + /* Change TAP position according to correction status */ + if (val & SH_MOBILE_SDHI_SCC_RVSREQ_RVSERR) + return true; /* Need re-tune */ + else if (val & SH_MOBILE_SDHI_SCC_RVSREQ_REQTAPUP) + host->tap_set = (host->tap_set + 1) % host->tap_num; + else if (val & SH_MOBILE_SDHI_SCC_RVSREQ_REQTAPDOWN) + host->tap_set = (host->tap_set - 1) % host->tap_num; + else + return false; + + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TAPSET, + host->tap_set / (use_4tap ? 2 : 1)); + + return false; +} + +static bool renesas_sdhi_auto_correction(struct tmio_mmc_host *host) +{ + struct renesas_sdhi *priv = host_to_priv(host); + + /* Check SCC error */ + if (sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ) & + SH_MOBILE_SDHI_SCC_RVSREQ_RVSERR) { + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ, 0); + return true; + } + + return false; +} + static bool renesas_sdhi_check_scc_error(struct tmio_mmc_host *host) { struct renesas_sdhi *priv = host_to_priv(host); @@ -499,20 +546,14 @@ static bool renesas_sdhi_check_scc_error(struct tmio_mmc_host *host) !(host->mmc->ios.timing == MMC_TIMING_MMC_HS400 && !use_4tap)) return false; - if (mmc_doing_retune(host->mmc)) + if (mmc_doing_retune(host->mmc) || priv->doing_tune) return false; - /* Check SCC error */ if (sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL) & - SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN && - sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ) & - SH_MOBILE_SDHI_SCC_RVSREQ_RVSERR) { - /* Clear SCC error */ - sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ, 0); - return true; - } + SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN) + return renesas_sdhi_auto_correction(host); - return false; + return renesas_sdhi_manual_correction(host, use_4tap); } static void renesas_sdhi_hw_reset(struct tmio_mmc_host *host) -- 2.25.1