From: Haibo Chen Date: Wed, 9 Apr 2025 07:55:48 +0000 (+0800) Subject: mmc: sdhci-esdhc-imx: widen auto-tuning window for manual tuning X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=8cdba34313712e0dbc4c5650c8f2dcf315c13e6f;p=users%2Fjedix%2Flinux-maple.git mmc: sdhci-esdhc-imx: widen auto-tuning window for manual tuning Expand the auto-tuning window width from 0 to 3 for manual tuning to account for sampling point shifts caused by temperature change. This change is based on hardware recommendation, providing enough margin for the auto-tuning logic to locate valid sampling points. When config the manual tuning final sample delay, need deduct the auto tuning window width according to the IP logic. Signed-off-by: Haibo Chen Signed-off-by: Luke Wang Acked-by: Adrian Hunter Link: https://lore.kernel.org/r/20250409075550.3413032-5-ziniu.wang_1@nxp.com Signed-off-by: Ulf Hansson --- diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index 5c8a00864c1d0..f94b5f08b432e 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -85,7 +85,8 @@ #define ESDHC_TUNE_CTRL_MAX ((1 << 7) - 1) #define ESDHC_TUNE_CTRL_STATUS_TAP_SEL_PRE_MASK GENMASK(30, 24) #define ESDHC_TUNE_CTRL_STATUS_DLY_CELL_SET_PRE_MASK GENMASK(14, 8) - +#define ESDHC_TUNE_CTRL_STATUS_DLY_CELL_SET_OUT_MASK GENMASK(7, 4) +#define ESDHC_TUNE_CTRL_STATUS_DLY_CELL_SET_POST_MASK GENMASK(3, 0) /* strobe dll register */ #define ESDHC_STROBE_DLL_CTRL 0x70 #define ESDHC_STROBE_DLL_CTRL_ENABLE (1 << 0) @@ -243,6 +244,7 @@ struct esdhc_platform_data { unsigned int tuning_start_tap; /* The start delay cell point in tuning procedure */ unsigned int strobe_dll_delay_target; /* The delay cell for strobe pad (read clock) */ unsigned int saved_tuning_delay_cell; /* save the value of tuning delay cell */ + unsigned int saved_auto_tuning_window; /* save the auto tuning window width */ }; struct esdhc_soc_data { @@ -1211,6 +1213,7 @@ static int esdhc_executing_tuning(struct sdhci_host *host, u32 opcode) { int min, max, avg, ret; int win_length, target_min, target_max, target_win_length; + u32 clk_tune_ctrl_status; min = ESDHC_TUNE_CTRL_MIN; max = ESDHC_TUNE_CTRL_MIN; @@ -1250,6 +1253,23 @@ static int esdhc_executing_tuning(struct sdhci_host *host, u32 opcode) /* use average delay to get the best timing */ avg = (target_min + target_max) / 2; esdhc_prepare_tuning(host, avg); + + /* + * adjust the delay according to tuning window, make preparation + * for the auto-tuning logic. According to hardware suggest, need + * to config the auto tuning window width to 3, to make the auto + * tuning logic have enough space to handle the sample point shift + * caused by temperature change. + */ + clk_tune_ctrl_status = FIELD_PREP(ESDHC_TUNE_CTRL_STATUS_DLY_CELL_SET_PRE_MASK, + avg - ESDHC_AUTO_TUNING_WINDOW) | + FIELD_PREP(ESDHC_TUNE_CTRL_STATUS_DLY_CELL_SET_OUT_MASK, + ESDHC_AUTO_TUNING_WINDOW) | + FIELD_PREP(ESDHC_TUNE_CTRL_STATUS_DLY_CELL_SET_POST_MASK, + ESDHC_AUTO_TUNING_WINDOW); + + writel(clk_tune_ctrl_status, host->ioaddr + ESDHC_TUNE_CTRL_STATUS); + ret = mmc_send_tuning(host->mmc, opcode, NULL); esdhc_post_tuning(host); @@ -1652,7 +1672,11 @@ static void sdhc_esdhc_tuning_restore(struct sdhci_host *host) writel(reg, host->ioaddr + ESDHC_MIX_CTRL); writel(FIELD_PREP(ESDHC_TUNE_CTRL_STATUS_DLY_CELL_SET_PRE_MASK, - imx_data->boarddata.saved_tuning_delay_cell), + imx_data->boarddata.saved_tuning_delay_cell) | + FIELD_PREP(ESDHC_TUNE_CTRL_STATUS_DLY_CELL_SET_OUT_MASK, + ESDHC_AUTO_TUNING_WINDOW) | + FIELD_PREP(ESDHC_TUNE_CTRL_STATUS_DLY_CELL_SET_POST_MASK, + ESDHC_AUTO_TUNING_WINDOW), host->ioaddr + ESDHC_TUNE_CTRL_STATUS); } }