]> git.dujemihanovic.xyz Git - u-boot.git/commitdiff
mmc: renesas-sdhi: Add Renesas SDR104/HS200 tuning support
authorMarek Vasut <marek.vasut+renesas@gmail.com>
Sun, 8 Apr 2018 17:09:17 +0000 (19:09 +0200)
committerMarek Vasut <marek.vasut+renesas@gmail.com>
Wed, 11 Apr 2018 21:11:59 +0000 (23:11 +0200)
Add code for PHY tuning required for SDR104/HS200 support on Renesas RCar.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
drivers/mmc/renesas-sdhi.c

index 73f68c8c3ac60b494121bf6c655a4776b2ebb8ed..e9edcf5f179934ed59a241f6ca44acb3e44958c6 100644 (file)
 
 #include "matsushita-common.h"
 
+#if CONFIG_IS_ENABLED(MMC_HS200_SUPPORT)
+
+/* SCC registers */
+#define RENESAS_SDHI_SCC_DTCNTL                        0x800
+#define   RENESAS_SDHI_SCC_DTCNTL_TAPEN                BIT(0)
+#define   RENESAS_SDHI_SCC_DTCNTL_TAPNUM_SHIFT 16
+#define   RENESAS_SDHI_SCC_DTCNTL_TAPNUM_MASK          0xff
+#define RENESAS_SDHI_SCC_TAPSET                        0x804
+#define RENESAS_SDHI_SCC_DT2FF                 0x808
+#define RENESAS_SDHI_SCC_CKSEL                 0x80c
+#define   RENESAS_SDHI_SCC_CKSEL_DTSEL         BIT(0)
+#define RENESAS_SDHI_SCC_RVSCNTL                       0x810
+#define   RENESAS_SDHI_SCC_RVSCNTL_RVSEN               BIT(0)
+#define RENESAS_SDHI_SCC_RVSREQ                        0x814
+#define   RENESAS_SDHI_SCC_RVSREQ_RVSERR               BIT(2)
+#define RENESAS_SDHI_SCC_SMPCMP                        0x818
+#define RENESAS_SDHI_SCC_TMPPORT2                      0x81c
+
+#define RENESAS_SDHI_MAX_TAP 3
+
+static unsigned int renesas_sdhi_init_tuning(struct matsu_sd_priv *priv)
+{
+       u32 reg;
+
+       /* Initialize SCC */
+       matsu_sd_writel(priv, 0, MATSU_SD_INFO1);
+
+       reg = matsu_sd_readl(priv, MATSU_SD_CLKCTL);
+       reg &= ~MATSU_SD_CLKCTL_SCLKEN;
+       matsu_sd_writel(priv, reg, MATSU_SD_CLKCTL);
+
+       /* Set sampling clock selection range */
+       matsu_sd_writel(priv, 0x8 << RENESAS_SDHI_SCC_DTCNTL_TAPNUM_SHIFT,
+                          RENESAS_SDHI_SCC_DTCNTL);
+
+       reg = matsu_sd_readl(priv, RENESAS_SDHI_SCC_DTCNTL);
+       reg |= RENESAS_SDHI_SCC_DTCNTL_TAPEN;
+       matsu_sd_writel(priv, reg, RENESAS_SDHI_SCC_DTCNTL);
+
+       reg = matsu_sd_readl(priv, RENESAS_SDHI_SCC_CKSEL);
+       reg |= RENESAS_SDHI_SCC_CKSEL_DTSEL;
+       matsu_sd_writel(priv, reg, RENESAS_SDHI_SCC_CKSEL);
+
+       reg = matsu_sd_readl(priv, RENESAS_SDHI_SCC_RVSCNTL);
+       reg &= ~RENESAS_SDHI_SCC_RVSCNTL_RVSEN;
+       matsu_sd_writel(priv, reg, RENESAS_SDHI_SCC_RVSCNTL);
+
+       matsu_sd_writel(priv, 0x300 /* scc_tappos */,
+                          RENESAS_SDHI_SCC_DT2FF);
+
+       reg = matsu_sd_readl(priv, MATSU_SD_CLKCTL);
+       reg |= MATSU_SD_CLKCTL_SCLKEN;
+       matsu_sd_writel(priv, reg, MATSU_SD_CLKCTL);
+
+       /* Read TAPNUM */
+       return (matsu_sd_readl(priv, RENESAS_SDHI_SCC_DTCNTL) >>
+               RENESAS_SDHI_SCC_DTCNTL_TAPNUM_SHIFT) &
+               RENESAS_SDHI_SCC_DTCNTL_TAPNUM_MASK;
+}
+
+static void renesas_sdhi_reset_tuning(struct matsu_sd_priv *priv)
+{
+       u32 reg;
+
+       /* Reset SCC */
+       reg = matsu_sd_readl(priv, MATSU_SD_CLKCTL);
+       reg &= ~MATSU_SD_CLKCTL_SCLKEN;
+       matsu_sd_writel(priv, reg, MATSU_SD_CLKCTL);
+
+       reg = matsu_sd_readl(priv, RENESAS_SDHI_SCC_CKSEL);
+       reg &= ~RENESAS_SDHI_SCC_CKSEL_DTSEL;
+       matsu_sd_writel(priv, reg, RENESAS_SDHI_SCC_CKSEL);
+
+       reg = matsu_sd_readl(priv, MATSU_SD_CLKCTL);
+       reg |= MATSU_SD_CLKCTL_SCLKEN;
+       matsu_sd_writel(priv, reg, MATSU_SD_CLKCTL);
+
+       reg = matsu_sd_readl(priv, RENESAS_SDHI_SCC_RVSCNTL);
+       reg &= ~RENESAS_SDHI_SCC_RVSCNTL_RVSEN;
+       matsu_sd_writel(priv, reg, RENESAS_SDHI_SCC_RVSCNTL);
+
+       reg = matsu_sd_readl(priv, RENESAS_SDHI_SCC_RVSCNTL);
+       reg &= ~RENESAS_SDHI_SCC_RVSCNTL_RVSEN;
+       matsu_sd_writel(priv, reg, RENESAS_SDHI_SCC_RVSCNTL);
+}
+
+static void renesas_sdhi_prepare_tuning(struct matsu_sd_priv *priv,
+                                      unsigned long tap)
+{
+       /* Set sampling clock position */
+       matsu_sd_writel(priv, tap, RENESAS_SDHI_SCC_TAPSET);
+}
+
+static unsigned int renesas_sdhi_compare_scc_data(struct matsu_sd_priv *priv)
+{
+       /* Get comparison of sampling data */
+       return matsu_sd_readl(priv, RENESAS_SDHI_SCC_SMPCMP);
+}
+
+static int renesas_sdhi_select_tuning(struct matsu_sd_priv *priv,
+                                    unsigned int tap_num, unsigned int taps,
+                                    unsigned int smpcmp)
+{
+       unsigned long tap_cnt;  /* counter of tuning success */
+       unsigned long tap_set;  /* tap position */
+       unsigned long tap_start;/* start position of tuning success */
+       unsigned long tap_end;  /* end position of tuning success */
+       unsigned long ntap;     /* temporary counter of tuning success */
+       unsigned long match_cnt;/* counter of matching data */
+       unsigned long i;
+       bool select = false;
+       u32 reg;
+
+       /* Clear SCC_RVSREQ */
+       matsu_sd_writel(priv, 0, RENESAS_SDHI_SCC_RVSREQ);
+
+       /* Merge the results */
+       for (i = 0; i < tap_num * 2; i++) {
+               if (!(taps & BIT(i))) {
+                       taps &= ~BIT(i % tap_num);
+                       taps &= ~BIT((i % tap_num) + tap_num);
+               }
+               if (!(smpcmp & BIT(i))) {
+                       smpcmp &= ~BIT(i % tap_num);
+                       smpcmp &= ~BIT((i % tap_num) + tap_num);
+               }
+       }
+
+       /*
+        * Find the longest consecutive run of successful probes.  If that
+        * is more than RENESAS_SDHI_MAX_TAP probes long then use the
+        * center index as the tap.
+        */
+       tap_cnt = 0;
+       ntap = 0;
+       tap_start = 0;
+       tap_end = 0;
+       for (i = 0; i < tap_num * 2; i++) {
+               if (taps & BIT(i))
+                       ntap++;
+               else {
+                       if (ntap > tap_cnt) {
+                               tap_start = i - ntap;
+                               tap_end = i - 1;
+                               tap_cnt = ntap;
+                       }
+                       ntap = 0;
+               }
+       }
+
+       if (ntap > tap_cnt) {
+               tap_start = i - ntap;
+               tap_end = i - 1;
+               tap_cnt = ntap;
+       }
+
+       /*
+        * If all of the TAP is OK, the sampling clock position is selected by
+        * identifying the change point of data.
+        */
+       if (tap_cnt == tap_num * 2) {
+               match_cnt = 0;
+               ntap = 0;
+               tap_start = 0;
+               tap_end = 0;
+               for (i = 0; i < tap_num * 2; i++) {
+                       if (smpcmp & BIT(i))
+                               ntap++;
+                       else {
+                               if (ntap > match_cnt) {
+                                       tap_start = i - ntap;
+                                       tap_end = i - 1;
+                                       match_cnt = ntap;
+                               }
+                               ntap = 0;
+                       }
+               }
+               if (ntap > match_cnt) {
+                       tap_start = i - ntap;
+                       tap_end = i - 1;
+                       match_cnt = ntap;
+               }
+               if (match_cnt)
+                       select = true;
+       } else if (tap_cnt >= RENESAS_SDHI_MAX_TAP)
+               select = true;
+
+       if (select)
+               tap_set = ((tap_start + tap_end) / 2) % tap_num;
+       else
+               return -EIO;
+
+       /* Set SCC */
+       matsu_sd_writel(priv, tap_set, RENESAS_SDHI_SCC_TAPSET);
+
+       /* Enable auto re-tuning */
+       reg = matsu_sd_readl(priv, RENESAS_SDHI_SCC_RVSCNTL);
+       reg |= RENESAS_SDHI_SCC_RVSCNTL_RVSEN;
+       matsu_sd_writel(priv, reg, RENESAS_SDHI_SCC_RVSCNTL);
+
+       return 0;
+}
+
+int renesas_sdhi_execute_tuning(struct udevice *dev, uint opcode)
+{
+       struct matsu_sd_priv *priv = dev_get_priv(dev);
+       struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
+       struct mmc *mmc = upriv->mmc;
+       unsigned int tap_num;
+       unsigned int taps = 0, smpcmp = 0;
+       int i, ret = 0;
+       u32 caps;
+
+       /* Only supported on Renesas RCar */
+       if (!(priv->caps & MATSU_SD_CAP_RCAR_UHS))
+               return -EINVAL;
+
+       /* clock tuning is not needed for upto 52MHz */
+       if (!((mmc->selected_mode == MMC_HS_200) ||
+             (mmc->selected_mode == UHS_SDR104) ||
+             (mmc->selected_mode == UHS_SDR50)))
+               return 0;
+
+       tap_num = renesas_sdhi_init_tuning(priv);
+       if (!tap_num)
+               /* Tuning is not supported */
+               goto out;
+
+       if (tap_num * 2 >= sizeof(taps) * 8) {
+               dev_err(dev,
+                       "Too many taps, skipping tuning. Please consider updating size of taps field of tmio_mmc_host\n");
+               goto out;
+       }
+
+       /* Issue CMD19 twice for each tap */
+       for (i = 0; i < 2 * tap_num; i++) {
+               renesas_sdhi_prepare_tuning(priv, i % tap_num);
+
+               /* Force PIO for the tuning */
+               caps = priv->caps;
+               priv->caps &= ~MATSU_SD_CAP_DMA_INTERNAL;
+
+               ret = mmc_send_tuning(mmc, opcode, NULL);
+
+               priv->caps = caps;
+
+               if (ret == 0)
+                       taps |= BIT(i);
+
+               ret = renesas_sdhi_compare_scc_data(priv);
+               if (ret == 0)
+                       smpcmp |= BIT(i);
+
+               mdelay(1);
+       }
+
+       ret = renesas_sdhi_select_tuning(priv, tap_num, taps, smpcmp);
+
+out:
+       if (ret < 0) {
+               dev_warn(dev, "Tuning procedure failed\n");
+               renesas_sdhi_reset_tuning(priv);
+       }
+
+       return ret;
+}
+#endif
+
+static int renesas_sdhi_set_ios(struct udevice *dev)
+{
+       int ret = matsu_sd_set_ios(dev);
+#if CONFIG_IS_ENABLED(MMC_HS200_SUPPORT)
+       struct matsu_sd_priv *priv = dev_get_priv(dev);
+
+       renesas_sdhi_reset_tuning(priv);
+#endif
+
+       return ret;
+}
+
 static const struct dm_mmc_ops renesas_sdhi_ops = {
        .send_cmd = matsu_sd_send_cmd,
-       .set_ios = matsu_sd_set_ios,
+       .set_ios = renesas_sdhi_set_ios,
        .get_cd = matsu_sd_get_cd,
+#if CONFIG_IS_ENABLED(MMC_HS200_SUPPORT)
+       .execute_tuning = renesas_sdhi_execute_tuning,
+#endif
 };
 
 #define RENESAS_GEN2_QUIRKS    MATSU_SD_CAP_RCAR_GEN2
@@ -62,7 +345,12 @@ static int renesas_sdhi_probe(struct udevice *dev)
                        quirks |= MATSU_SD_CAP_16BIT;
        }
 
-       return matsu_sd_probe(dev, quirks);
+       ret = matsu_sd_probe(dev, quirks);
+#if CONFIG_IS_ENABLED(MMC_HS200_SUPPORT)
+       if (!ret)
+               renesas_sdhi_reset_tuning(dev_get_priv(dev));
+#endif
+       return ret;
 }
 
 U_BOOT_DRIVER(renesas_sdhi) = {