From 67b5870a35bbf9dba72fe8e94036cbb3bbc8f60a Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Sat, 25 Jun 2022 15:17:22 +0200 Subject: [PATCH] mmc: tmio: avoid glitches when resetting [ Upstream commit 2e586f8a5b0ed4a525014a692923ac96f6647816 ] If we reset because of an error, we need to preserve values for the clock frequency. Otherwise, glitches may be seen on the bus. To achieve that, we introduce a 'preserve' parameter to the reset function and the IP core specific reset callbacks to handle everything accordingly. Reported-by: Yoshihiro Shimoda Signed-off-by: Wolfram Sang Tested-by: Yoshihiro Shimoda Link: https://lore.kernel.org/r/20220625131722.1397-1-wsa@kernel.org Signed-off-by: Ulf Hansson Signed-off-by: Sasha Levin --- drivers/mmc/host/renesas_sdhi_core.c | 29 ++++++++++++++--------------- drivers/mmc/host/tmio_mmc.c | 2 +- drivers/mmc/host/tmio_mmc.h | 6 +++++- drivers/mmc/host/tmio_mmc_core.c | 28 ++++++++++++++++++++++------ 4 files changed, 42 insertions(+), 23 deletions(-) diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c index 791e180..387f2a4 100644 --- a/drivers/mmc/host/renesas_sdhi_core.c +++ b/drivers/mmc/host/renesas_sdhi_core.c @@ -51,9 +51,6 @@ #define HOST_MODE_GEN3_32BIT (HOST_MODE_GEN3_WMODE | HOST_MODE_GEN3_BUSWIDTH) #define HOST_MODE_GEN3_64BIT 0 -#define CTL_SDIF_MODE 0xe6 -#define SDIF_MODE_HS400 BIT(0) - #define SDHI_VER_GEN2_SDR50 0x490c #define SDHI_VER_RZ_A1 0x820b /* very old datasheets said 0x490c for SDR104, too. They are wrong! */ @@ -550,23 +547,25 @@ static void renesas_sdhi_scc_reset(struct tmio_mmc_host *host, struct renesas_sd } /* only populated for TMIO_MMC_MIN_RCAR2 */ -static void renesas_sdhi_reset(struct tmio_mmc_host *host) +static void renesas_sdhi_reset(struct tmio_mmc_host *host, bool preserve) { struct renesas_sdhi *priv = host_to_priv(host); int ret; u16 val; - if (priv->rstc) { - reset_control_reset(priv->rstc); - /* Unknown why but without polling reset status, it will hang */ - read_poll_timeout(reset_control_status, ret, ret == 0, 1, 100, - false, priv->rstc); - /* At least SDHI_VER_GEN2_SDR50 needs manual release of reset */ - sd_ctrl_write16(host, CTL_RESET_SD, 0x0001); - priv->needs_adjust_hs400 = false; - renesas_sdhi_set_clock(host, host->clk_cache); - } else if (priv->scc_ctl) { - renesas_sdhi_scc_reset(host, priv); + if (!preserve) { + if (priv->rstc) { + reset_control_reset(priv->rstc); + /* Unknown why but without polling reset status, it will hang */ + read_poll_timeout(reset_control_status, ret, ret == 0, 1, 100, + false, priv->rstc); + /* At least SDHI_VER_GEN2_SDR50 needs manual release of reset */ + sd_ctrl_write16(host, CTL_RESET_SD, 0x0001); + priv->needs_adjust_hs400 = false; + renesas_sdhi_set_clock(host, host->clk_cache); + } else if (priv->scc_ctl) { + renesas_sdhi_scc_reset(host, priv); + } } if (sd_ctrl_read16(host, CTL_VERSION) >= SDHI_VER_GEN3_SD) { diff --git a/drivers/mmc/host/tmio_mmc.c b/drivers/mmc/host/tmio_mmc.c index b55a29c..53a2ad9 100644 --- a/drivers/mmc/host/tmio_mmc.c +++ b/drivers/mmc/host/tmio_mmc.c @@ -75,7 +75,7 @@ static void tmio_mmc_set_clock(struct tmio_mmc_host *host, tmio_mmc_clk_start(host); } -static void tmio_mmc_reset(struct tmio_mmc_host *host) +static void tmio_mmc_reset(struct tmio_mmc_host *host, bool preserve) { sd_ctrl_write16(host, CTL_RESET_SDIO, 0x0000); usleep_range(10000, 11000); diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h index f936aad..da63193 100644 --- a/drivers/mmc/host/tmio_mmc.h +++ b/drivers/mmc/host/tmio_mmc.h @@ -42,6 +42,7 @@ #define CTL_DMA_ENABLE 0xd8 #define CTL_RESET_SD 0xe0 #define CTL_VERSION 0xe2 +#define CTL_SDIF_MODE 0xe6 /* only known on R-Car 2+ */ /* Definitions for values the CTL_STOP_INTERNAL_ACTION register can take */ #define TMIO_STOP_STP BIT(0) @@ -98,6 +99,9 @@ /* Definitions for values the CTL_DMA_ENABLE register can take */ #define DMA_ENABLE_DMASDRW BIT(1) +/* Definitions for values the CTL_SDIF_MODE register can take */ +#define SDIF_MODE_HS400 BIT(0) /* only known on R-Car 2+ */ + /* Define some IRQ masks */ /* This is the mask used at reset by the chip */ #define TMIO_MASK_ALL 0x837f031d @@ -181,7 +185,7 @@ struct tmio_mmc_host { int (*multi_io_quirk)(struct mmc_card *card, unsigned int direction, int blk_size); int (*write16_hook)(struct tmio_mmc_host *host, int addr); - void (*reset)(struct tmio_mmc_host *host); + void (*reset)(struct tmio_mmc_host *host, bool preserve); bool (*check_retune)(struct tmio_mmc_host *host, struct mmc_request *mrq); void (*fixup_request)(struct tmio_mmc_host *host, struct mmc_request *mrq); unsigned int (*get_timeout_cycles)(struct tmio_mmc_host *host); diff --git a/drivers/mmc/host/tmio_mmc_core.c b/drivers/mmc/host/tmio_mmc_core.c index a5850d8..437048b 100644 --- a/drivers/mmc/host/tmio_mmc_core.c +++ b/drivers/mmc/host/tmio_mmc_core.c @@ -179,8 +179,17 @@ static void tmio_mmc_set_bus_width(struct tmio_mmc_host *host, sd_ctrl_write16(host, CTL_SD_MEM_CARD_OPT, reg); } -static void tmio_mmc_reset(struct tmio_mmc_host *host) +static void tmio_mmc_reset(struct tmio_mmc_host *host, bool preserve) { + u16 card_opt, clk_ctrl, sdif_mode; + + if (preserve) { + card_opt = sd_ctrl_read16(host, CTL_SD_MEM_CARD_OPT); + clk_ctrl = sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL); + if (host->pdata->flags & TMIO_MMC_MIN_RCAR2) + sdif_mode = sd_ctrl_read16(host, CTL_SDIF_MODE); + } + /* FIXME - should we set stop clock reg here */ sd_ctrl_write16(host, CTL_RESET_SD, 0x0000); usleep_range(10000, 11000); @@ -190,7 +199,7 @@ static void tmio_mmc_reset(struct tmio_mmc_host *host) tmio_mmc_abort_dma(host); if (host->reset) - host->reset(host); + host->reset(host, preserve); sd_ctrl_write32_as_16_and_16(host, CTL_IRQ_MASK, host->sdcard_irq_mask_all); host->sdcard_irq_mask = host->sdcard_irq_mask_all; @@ -206,6 +215,13 @@ static void tmio_mmc_reset(struct tmio_mmc_host *host) sd_ctrl_write16(host, CTL_TRANSACTION_CTL, 0x0001); } + if (preserve) { + sd_ctrl_write16(host, CTL_SD_MEM_CARD_OPT, card_opt); + sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, clk_ctrl); + if (host->pdata->flags & TMIO_MMC_MIN_RCAR2) + sd_ctrl_write16(host, CTL_SDIF_MODE, sdif_mode); + } + if (host->mmc->card) mmc_retune_needed(host->mmc); } @@ -248,7 +264,7 @@ static void tmio_mmc_reset_work(struct work_struct *work) spin_unlock_irqrestore(&host->lock, flags); - tmio_mmc_reset(host); + tmio_mmc_reset(host, true); /* Ready for new calls */ host->mrq = NULL; @@ -961,7 +977,7 @@ static void tmio_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) tmio_mmc_power_off(host); /* For R-Car Gen2+, we need to reset SDHI specific SCC */ if (host->pdata->flags & TMIO_MMC_MIN_RCAR2) - tmio_mmc_reset(host); + tmio_mmc_reset(host, false); host->set_clock(host, 0); break; @@ -1189,7 +1205,7 @@ int tmio_mmc_host_probe(struct tmio_mmc_host *_host) _host->sdcard_irq_mask_all = TMIO_MASK_ALL; _host->set_clock(_host, 0); - tmio_mmc_reset(_host); + tmio_mmc_reset(_host, false); spin_lock_init(&_host->lock); mutex_init(&_host->ios_lock); @@ -1285,7 +1301,7 @@ int tmio_mmc_host_runtime_resume(struct device *dev) struct tmio_mmc_host *host = dev_get_drvdata(dev); tmio_mmc_clk_enable(host); - tmio_mmc_reset(host); + tmio_mmc_reset(host, false); if (host->clk_cache) host->set_clock(host, host->clk_cache); -- 2.7.4