On Sat, 20 Apr 2024 at 04:28, Jisheng Zhang <jszhang@xxxxxxxxxx> wrote:
>
> Implement the .platform_execute_tuning for Sophgo CV1800B and SG200X.
> Some code is borrowed from sdhci-esdhc-imx.c. The tuning result is
> similar as the one of SoC vendor's SDK.
>
> Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
> Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Applied for next, thanks!
Kind regards
Uffe
> ---
>
> Since v1:
> - use usleep_range() instead of mdelay() as suggested by Adrian
>
> drivers/mmc/host/sdhci-of-dwcmshc.c | 112 ++++++++++++++++++++++++++++
> 1 file changed, 112 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
> index ab4b964d4058..7b55acd9830c 100644
> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> @@ -66,6 +66,10 @@
> #define CV18XX_SDHCI_PHY_CONFIG 0x4c
> #define CV18XX_PHY_TX_BPS BIT(0)
>
> +#define CV18XX_TUNE_MAX 128
> +#define CV18XX_TUNE_STEP 1
> +#define CV18XX_RETRY_TUNING_MAX 50
> +
> /* Rockchip specific Registers */
> #define DWCMSHC_EMMC_DLL_CTRL 0x800
> #define DWCMSHC_EMMC_DLL_RXCLK 0x804
> @@ -685,6 +689,113 @@ static void cv18xx_sdhci_reset(struct sdhci_host *host, u8 mask)
> sdhci_writel(host, val, priv->vendor_specific_area1 + CV18XX_SDHCI_PHY_TX_RX_DLY);
> }
>
> +static void cv18xx_sdhci_set_tap(struct sdhci_host *host, int tap)
> +{
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
> + u16 clk;
> + u32 val;
> +
> + clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> + clk &= ~SDHCI_CLOCK_CARD_EN;
> + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +
> + val = sdhci_readl(host, priv->vendor_specific_area1 + CV18XX_SDHCI_MSHC_CTRL);
> + val &= ~CV18XX_LATANCY_1T;
> + sdhci_writel(host, val, priv->vendor_specific_area1 + CV18XX_SDHCI_MSHC_CTRL);
> +
> + val = (FIELD_PREP(CV18XX_PHY_TX_DLY_MSK, 0) |
> + FIELD_PREP(CV18XX_PHY_TX_SRC_MSK, CV18XX_PHY_TX_SRC_INVERT_CLK_TX) |
> + FIELD_PREP(CV18XX_PHY_RX_DLY_MSK, tap));
> + sdhci_writel(host, val, priv->vendor_specific_area1 + CV18XX_SDHCI_PHY_TX_RX_DLY);
> +
> + sdhci_writel(host, 0, priv->vendor_specific_area1 + CV18XX_SDHCI_PHY_CONFIG);
> +
> + clk |= SDHCI_CLOCK_CARD_EN;
> + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> + usleep_range(1000, 2000);
> +}
> +
> +static int cv18xx_retry_tuning(struct mmc_host *mmc, u32 opcode, int *cmd_error)
> +{
> + int ret, retry = 0;
> +
> + while (retry < CV18XX_RETRY_TUNING_MAX) {
> + ret = mmc_send_tuning(mmc, opcode, NULL);
> + if (ret)
> + return ret;
> + retry++;
> + }
> +
> + return 0;
> +}
> +
> +static void cv18xx_sdhci_post_tuning(struct sdhci_host *host)
> +{
> + u32 val;
> +
> + val = sdhci_readl(host, SDHCI_INT_STATUS);
> + val |= SDHCI_INT_DATA_AVAIL;
> + sdhci_writel(host, val, SDHCI_INT_STATUS);
> +
> + sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
> +}
> +
> +static int cv18xx_sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
> +{
> + int min, max, avg, ret;
> + int win_length, target_min, target_max, target_win_length;
> +
> + min = max = 0;
> + target_win_length = 0;
> +
> + sdhci_reset_tuning(host);
> +
> + while (max < CV18XX_TUNE_MAX) {
> + /* find the mininum delay first which can pass tuning */
> + while (min < CV18XX_TUNE_MAX) {
> + cv18xx_sdhci_set_tap(host, min);
> + if (!cv18xx_retry_tuning(host->mmc, opcode, NULL))
> + break;
> + min += CV18XX_TUNE_STEP;
> + }
> +
> + /* find the maxinum delay which can not pass tuning */
> + max = min + CV18XX_TUNE_STEP;
> + while (max < CV18XX_TUNE_MAX) {
> + cv18xx_sdhci_set_tap(host, max);
> + if (cv18xx_retry_tuning(host->mmc, opcode, NULL)) {
> + max -= CV18XX_TUNE_STEP;
> + break;
> + }
> + max += CV18XX_TUNE_STEP;
> + }
> +
> + win_length = max - min + 1;
> + /* get the largest pass window */
> + if (win_length > target_win_length) {
> + target_win_length = win_length;
> + target_min = min;
> + target_max = max;
> + }
> +
> + /* continue to find the next pass window */
> + min = max + CV18XX_TUNE_STEP;
> + }
> +
> + cv18xx_sdhci_post_tuning(host);
> +
> + /* use average delay to get the best timing */
> + avg = (target_min + target_max) / 2;
> + cv18xx_sdhci_set_tap(host, avg);
> + ret = mmc_send_tuning(host->mmc, opcode, NULL);
> +
> + dev_dbg(mmc_dev(host->mmc), "tuning %s at 0x%x ret %d\n",
> + ret ? "failed" : "passed", avg, ret);
> +
> + return ret;
> +}
> +
> static const struct sdhci_ops sdhci_dwcmshc_ops = {
> .set_clock = sdhci_set_clock,
> .set_bus_width = sdhci_set_bus_width,
> @@ -721,6 +832,7 @@ static const struct sdhci_ops sdhci_dwcmshc_cv18xx_ops = {
> .get_max_clock = dwcmshc_get_max_clock,
> .reset = cv18xx_sdhci_reset,
> .adma_write_desc = dwcmshc_adma_write_desc,
> + .platform_execute_tuning = cv18xx_sdhci_execute_tuning,
> };
>
> static const struct sdhci_pltfm_data sdhci_dwcmshc_pdata = {
> --
> 2.43.0
>
