[U-Boot] [PATCH 6/6] mmc: uniphier-sd: Add Renesas SDR104/HS200 tuning support
Marek Vasut
marek.vasut at gmail.com
Fri Oct 6 12:07:07 UTC 2017
Add code for PHY tuning required for SDR104/HS200 support on Renesas RCar.
Signed-off-by: Marek Vasut <marek.vasut+renesas at gmail.com>
Cc: Jaehoon Chung <jh80.chung at samsung.com>
Cc: Masahiro Yamada <yamada.masahiro at socionext.com>
---
drivers/mmc/uniphier-sd.c | 280 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 280 insertions(+)
diff --git a/drivers/mmc/uniphier-sd.c b/drivers/mmc/uniphier-sd.c
index 4456d0ed43..bb52315ec9 100644
--- a/drivers/mmc/uniphier-sd.c
+++ b/drivers/mmc/uniphier-sd.c
@@ -143,6 +143,8 @@ struct uniphier_sd_priv {
#endif
};
+static void uniphier_sd_reset_tuning(struct uniphier_sd_priv *priv);
+
static u64 uniphier_sd_readq(struct uniphier_sd_priv *priv, unsigned int reg)
{
if (priv->caps & UNIPHIER_SD_CAP_64BIT)
@@ -596,6 +598,7 @@ static int uniphier_sd_set_bus_width(struct uniphier_sd_priv *priv,
u32 val, tmp;
switch (mmc->bus_width) {
+ case 0:
case 1:
val = UNIPHIER_SD_OPTION_WIDTH_1;
break;
@@ -694,6 +697,7 @@ static void uniphier_sd_set_pins(struct udevice *dev)
regulator_set_value(priv->vqmmc_dev, 1800000);
else
regulator_set_value(priv->vqmmc_dev, 3300000);
+ regulator_set_enable(priv->vqmmc_dev, true);
}
if (mmc->signal_voltage == MMC_SIGNAL_VOLTAGE_180)
@@ -718,6 +722,9 @@ static int uniphier_sd_set_ios(struct udevice *dev)
uniphier_sd_set_clk_rate(priv, mmc);
uniphier_sd_set_pins(dev);
+ if (priv->caps & UNIPHIER_SD_CAP_RCAR_UHS)
+ uniphier_sd_reset_tuning(priv);
+
return 0;
}
@@ -732,10 +739,280 @@ static int uniphier_sd_get_cd(struct udevice *dev)
UNIPHIER_SD_INFO1_CD);
}
+/*
+ * Renesas RCar SDR104 / HS200
+ */
+
+/* SCC registers */
+#define SH_MOBILE_SDHI_SCC_DTCNTL 0x800
+#define SH_MOBILE_SDHI_SCC_DTCNTL_TAPEN BIT(0)
+#define SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_SHIFT 16
+#define SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_MASK 0xff
+#define SH_MOBILE_SDHI_SCC_TAPSET 0x804
+#define SH_MOBILE_SDHI_SCC_DT2FF 0x808
+#define SH_MOBILE_SDHI_SCC_CKSEL 0x80c
+#define SH_MOBILE_SDHI_SCC_CKSEL_DTSEL BIT(0)
+#define SH_MOBILE_SDHI_SCC_RVSCNTL 0x810
+#define SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN BIT(0)
+#define SH_MOBILE_SDHI_SCC_RVSREQ 0x814
+#define SH_MOBILE_SDHI_SCC_RVSREQ_RVSERR BIT(2)
+#define SH_MOBILE_SDHI_SCC_SMPCMP 0x818
+#define SH_MOBILE_SDHI_SCC_TMPPORT2 0x81c
+
+#define SH_MOBILE_SDHI_MAX_TAP 3
+
+static unsigned int uniphier_sd_init_tuning(struct uniphier_sd_priv *priv)
+{
+ u32 reg;
+
+ /* Initialize SCC */
+ uniphier_sd_writel(priv, 0, UNIPHIER_SD_INFO1);
+
+ reg = uniphier_sd_readl(priv, UNIPHIER_SD_CLKCTL);
+ reg &= ~UNIPHIER_SD_CLKCTL_SCLKEN;
+ uniphier_sd_writel(priv, reg, UNIPHIER_SD_CLKCTL);
+
+ /* Set sampling clock selection range */
+ uniphier_sd_writel(priv, 0x8 << SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_SHIFT,
+ SH_MOBILE_SDHI_SCC_DTCNTL);
+
+ reg = uniphier_sd_readl(priv, SH_MOBILE_SDHI_SCC_DTCNTL);
+ reg |= SH_MOBILE_SDHI_SCC_DTCNTL_TAPEN;
+ uniphier_sd_writel(priv, reg, SH_MOBILE_SDHI_SCC_DTCNTL);
+
+ reg = uniphier_sd_readl(priv, SH_MOBILE_SDHI_SCC_CKSEL);
+ reg |= SH_MOBILE_SDHI_SCC_CKSEL_DTSEL;
+ uniphier_sd_writel(priv, reg, SH_MOBILE_SDHI_SCC_CKSEL);
+
+ reg = uniphier_sd_readl(priv, SH_MOBILE_SDHI_SCC_RVSCNTL);
+ reg &= ~SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN;
+ uniphier_sd_writel(priv, reg, SH_MOBILE_SDHI_SCC_RVSCNTL);
+
+ uniphier_sd_writel(priv, 0x300 /* scc_tappos */,
+ SH_MOBILE_SDHI_SCC_DT2FF);
+
+ reg = uniphier_sd_readl(priv, UNIPHIER_SD_CLKCTL);
+ reg |= UNIPHIER_SD_CLKCTL_SCLKEN;
+ uniphier_sd_writel(priv, reg, UNIPHIER_SD_CLKCTL);
+
+ /* Read TAPNUM */
+ return (uniphier_sd_readl(priv, SH_MOBILE_SDHI_SCC_DTCNTL) >>
+ SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_SHIFT) &
+ SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_MASK;
+}
+
+static void uniphier_sd_reset_tuning(struct uniphier_sd_priv *priv)
+{
+ u32 reg;
+
+ /* Reset SCC */
+ reg = uniphier_sd_readl(priv, UNIPHIER_SD_CLKCTL);
+ reg &= ~UNIPHIER_SD_CLKCTL_SCLKEN;
+ uniphier_sd_writel(priv, reg, UNIPHIER_SD_CLKCTL);
+
+ reg = uniphier_sd_readl(priv, SH_MOBILE_SDHI_SCC_CKSEL);
+ reg &= ~SH_MOBILE_SDHI_SCC_CKSEL_DTSEL;
+ uniphier_sd_writel(priv, reg, SH_MOBILE_SDHI_SCC_CKSEL);
+
+ reg = uniphier_sd_readl(priv, UNIPHIER_SD_CLKCTL);
+ reg |= UNIPHIER_SD_CLKCTL_SCLKEN;
+ uniphier_sd_writel(priv, reg, UNIPHIER_SD_CLKCTL);
+
+ reg = uniphier_sd_readl(priv, SH_MOBILE_SDHI_SCC_RVSCNTL);
+ reg &= ~SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN;
+ uniphier_sd_writel(priv, reg, SH_MOBILE_SDHI_SCC_RVSCNTL);
+
+ reg = uniphier_sd_readl(priv, SH_MOBILE_SDHI_SCC_RVSCNTL);
+ reg &= ~SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN;
+ uniphier_sd_writel(priv, reg, SH_MOBILE_SDHI_SCC_RVSCNTL);
+}
+
+static void uniphier_sd_prepare_tuning(struct uniphier_sd_priv *priv,
+ unsigned long tap)
+{
+ /* Set sampling clock position */
+ uniphier_sd_writel(priv, tap, SH_MOBILE_SDHI_SCC_TAPSET);
+}
+
+static unsigned int sh_mobile_sdhi_compare_scc_data(struct uniphier_sd_priv *priv)
+{
+ /* Get comparison of sampling data */
+ return uniphier_sd_readl(priv, SH_MOBILE_SDHI_SCC_SMPCMP);
+}
+
+static int uniphier_sd_select_tuning(struct uniphier_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 */
+ uniphier_sd_writel(priv, 0, SH_MOBILE_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 SH_MOBILE_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 >= SH_MOBILE_SDHI_MAX_TAP)
+ select = true;
+
+ if (select)
+ tap_set = ((tap_start + tap_end) / 2) % tap_num;
+ else
+ return -EIO;
+
+ /* Set SCC */
+ uniphier_sd_writel(priv, tap_set, SH_MOBILE_SDHI_SCC_TAPSET);
+
+ /* Enable auto re-tuning */
+ reg = uniphier_sd_readl(priv, SH_MOBILE_SDHI_SCC_RVSCNTL);
+ reg |= SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN;
+ uniphier_sd_writel(priv, reg, SH_MOBILE_SDHI_SCC_RVSCNTL);
+
+ return 0;
+}
+
+static int uniphier_sd_execute_tuning(struct udevice *dev, uint opcode)
+{
+ struct uniphier_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 & UNIPHIER_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 = uniphier_sd_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++) {
+ uniphier_sd_prepare_tuning(priv, i % tap_num);
+
+ /* Force PIO for the tuning */
+ caps = priv->caps;
+ priv->caps &= ~UNIPHIER_SD_CAP_DMA_INTERNAL;
+
+ ret = mmc_send_tuning(mmc, opcode, NULL);
+
+ priv->caps = caps;
+
+ if (ret == 0)
+ taps |= BIT(i);
+
+ ret = sh_mobile_sdhi_compare_scc_data(priv);
+ if (ret == 0)
+ smpcmp |= BIT(i);
+
+ mdelay(1);
+ }
+
+ ret = uniphier_sd_select_tuning(priv, tap_num, taps, smpcmp);
+
+out:
+ if (ret < 0) {
+ dev_warn(dev, "Tuning procedure failed\n");
+ uniphier_sd_reset_tuning(priv);
+ }
+
+ return ret;
+}
+
static const struct dm_mmc_ops uniphier_sd_ops = {
.send_cmd = uniphier_sd_send_cmd,
.set_ios = uniphier_sd_set_ios,
.get_cd = uniphier_sd_get_cd,
+ .execute_tuning = uniphier_sd_execute_tuning,
};
static void uniphier_sd_host_init(struct uniphier_sd_priv *priv)
@@ -852,6 +1129,9 @@ static int uniphier_sd_probe(struct udevice *dev)
upriv->mmc = &plat->mmc;
+ if (priv->caps & UNIPHIER_SD_CAP_RCAR_UHS)
+ uniphier_sd_reset_tuning(priv);
+
return 0;
}
--
2.11.0
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