MMC framework has already implemented hs200 mode for eMMC devices,
moreover the standard SDHC3.0 controller support tuning. We can set the
corresponding flag in host->host_cpas.
Host driver issue tuning command repeatedly until the host controller
resets Execute Tuning to 0. Host controller resets Execute Tuning to 0
when tuning is completed or tuning is not completed within 40 times.
Host driver can abort this loop by 40 times CMD19/CMD21 issue or 150ms
time-out. If tuning is completed successfully, driver set Sampling Clock
Select to 1 and this means the host contorller start to use tuned
sampling clcok. If tuning is failed, host controller keeps Sampling
Clock Select to 0.
Signed-off-by: Ziyuan Xu <xzy...@rock-chips.com>
---
drivers/mmc/sdhci.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 115 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
index b9cd13a..e346820 100644
--- a/drivers/mmc/sdhci.c
+++ b/drivers/mmc/sdhci.c
@@ -158,7 +158,10 @@ static int sdhci_send_command(struct mmc *mmc, struct
mmc_cmd *cmd,
static unsigned int cmd_timeout = SDHCI_CMD_DEFAULT_TIMEOUT;
sdhci_writel(host, SDHCI_INT_ALL_MASK, SDHCI_INT_STATUS);
- mask = SDHCI_CMD_INHIBIT | SDHCI_DATA_INHIBIT;
+ mask = SDHCI_CMD_INHIBIT;
+
+ if (data)
+ mask |= SDHCI_DATA_INHIBIT;
/* We shouldn't wait for data inihibit for stop commands, even
though they might use busy signaling */
@@ -200,6 +203,13 @@ static int sdhci_send_command(struct mmc *mmc, struct
mmc_cmd *cmd,
if (data)
flags |= SDHCI_CMD_DATA;
+ if (cmd->cmdidx == MMC_SEND_TUNING_BLOCK ||
+ cmd->cmdidx == MMC_SEND_TUNING_BLOCK_HS200) {
+ mask &= ~SDHCI_INT_RESPONSE;
+ mask |= SDHCI_INT_DATA_AVAIL;
+ flags |= SDHCI_CMD_DATA;
+ }
+
/* Set Transfer mode regarding to data flag */
if (data != 0) {
sdhci_writeb(host, 0xe, SDHCI_TIMEOUT_CONTROL);
@@ -559,6 +569,108 @@ static int sdhci_init(struct mmc *mmc)
return 0;
}
+static int sdhci_send_tuning(struct sdhci_host *host, u32 opcode)
+{
+ struct mmc_cmd cmd;
+
+ cmd.cmdidx = opcode;
+ cmd.resp_type = MMC_RSP_R1;
+ cmd.cmdarg = 0;
+ /*
+ * In response to CMD19, the card sends 64 bytes of tuning
+ * block to the Host Controller. So we set the block size
+ * to 64 here.
+ */
+ if (opcode == MMC_SEND_TUNING_BLOCK_HS200 &&
+ host->mmc->bus_width == MMC_BUS_WIDTH_8BIT)
+ sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, 128), SDHCI_BLOCK_SIZE);
+ else
+ sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, 64), SDHCI_BLOCK_SIZE);
+
+ /*
+ * The tuning block is sent by the card to the host controller.
+ * So we set the TRNS_READ bit in the Transfer Mode register.
+ * This also takes care of setting DMA Enable and Multi Block
+ * Select in the same register to 0.
+ */
+ sdhci_writew(host, SDHCI_TRNS_READ, SDHCI_TRANSFER_MODE);
+
+#ifdef CONFIG_DM_MMC_OPS
+ return sdhci_send_command(host->mmc->dev, &cmd, NULL);
+#else
+ return sdhci_send_command(host->mmc, &cmd, NULL);
+#endif
+}
+
+#define MAX_TUNING_LOOP 40
+static int __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
+{
+ int i;
+ int ret;
+
+ /*
+ * Issue opcode repeatedly till Execute Tuning is set to 0 or the number
+ * of loops reaches 40 times.
+ */
+ for (i = 0; i < MAX_TUNING_LOOP; i++) {
+ u16 ctrl;
+
+ ret = sdhci_send_tuning(host, opcode);
+
+ if (ret)
+ return ret;
+
+ ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+ if (!(ctrl & SDHCI_CTRL_EXEC_TUNING)) {
+ if (ctrl & SDHCI_CTRL_TUNED_CLK)
+ /* Tuning successfully */
+ return 0;
+ break;
+ }
+ }
+
+ return -ETIMEDOUT;
+}
+
+#ifdef CONFIG_DM_MMC_OPS
+static int sdhci_execute_tuning(struct udevice *dev, u32 opcode)
+{
+ struct mmc *mmc = mmc_get_mmc_dev(dev);
+#else
+static int sdhci_execute_tuning(struct mmc *mmc, u32 opcode)
+{
+#endif
+ struct sdhci_host *host = mmc->priv;
+ u16 ctrl;
+
+ /*
+ * The Host Controller needs tuning in case of SDR104 and DDR50
+ * mode, and for SDR50 mode when Use Tuning for SDR50 is set in
+ * the Capabilities register.
+ * If the Host Controller supports the HS200 mode then the
+ * tuning function has to be executed.
+ */
+ switch (mmc->timing) {
+ /* HS400 tuning is done in HS200 mode */
+ case MMC_TIMING_MMC_HS400:
+ return -EINVAL;
+ case MMC_TIMING_MMC_HS200:
+ /*
+ * Periodic re-tuning for HS400 is not expected to be needed, so
+ * disable it here.
+ */
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+ ctrl |= SDHCI_CTRL_EXEC_TUNING;
+ sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+
+ return __sdhci_execute_tuning(host, opcode);
+}
+
#ifdef CONFIG_DM_MMC_OPS
int sdhci_probe(struct udevice *dev)
{
@@ -571,6 +683,7 @@ const struct dm_mmc_ops sdhci_ops = {
.card_busy = sdhci_card_busy,
.send_cmd = sdhci_send_command,
.set_ios = sdhci_set_ios,
+ .execute_tuning = sdhci_execute_tuning,
};
#else
static const struct mmc_ops sdhci_ops = {
@@ -578,6 +691,7 @@ static const struct mmc_ops sdhci_ops = {
.send_cmd = sdhci_send_command,
.set_ios = sdhci_set_ios,
.init = sdhci_init,
+ .execute_tuning = sdhci_execute_tuning,
};
#endif
--
2.7.4
_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
https://lists.denx.de/listinfo/u-boot
