On 11/08/20 11:37 am, haibo.chen@xxxxxxx wrote:
> From: Haibo Chen <haibo.chen@xxxxxxx>
>
> According to IC suggestion, everytime before sending the tuning command,
> need to reset the usdhc, so to reset the tuning circuit, to let every
> tuning command work well for the manual tuning method. For standard
> tuning method, IC already add the reset operation in the hardware logic.
>
> Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-esdhc-imx.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index a76b4513fbec..cf335c661cc7 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -987,10 +987,20 @@ static int usdhc_execute_tuning(struct mmc_host *mmc, u32 opcode)
> static void esdhc_prepare_tuning(struct sdhci_host *host, u32 val)
> {
> u32 reg;
> + u8 sw_rst;
> + int ret;
>
> /* FIXME: delay a bit for card to be ready for next tuning due to errors */
> mdelay(1);
>
> + /* IC suggest to reset USDHC before every tuning command */
> + esdhc_clrset_le(host, 0xff, SDHCI_RESET_ALL, SDHCI_SOFTWARE_RESET);
> + ret = readb_poll_timeout(host->ioaddr + SDHCI_SOFTWARE_RESET, sw_rst,
> + !(sw_rst & SDHCI_RESET_ALL), 10, 100);
> + if (ret == -ETIMEDOUT)
> + dev_warn(mmc_dev(host->mmc),
> + "warning! RESET_ALL never complete before sending tuning command\n");
> +
> reg = readl(host->ioaddr + ESDHC_MIX_CTRL);
> reg |= ESDHC_MIX_CTRL_EXE_TUNE | ESDHC_MIX_CTRL_SMPCLK_SEL |
> ESDHC_MIX_CTRL_FBCLK_SEL;
>
