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authorT Karthik Reddy2021-08-02 23:20:45 -0600
committerMichal Simek2021-08-26 08:08:11 +0200
commitb6f44082d5cd2ea2758f09df4e364ded6f81323a (patch)
tree9e143d1ca529cf61e6108f8d23f0fc357878b46a
parent655d69faaf4bb1e7d3e9c31f07259b61c27e719e (diff)
mmc: zynq_sdhci: Wait till sd card detect state is stable
As per SD spec when SD host controller is reset, it takes 1000msec to detect the card state. In case, if we enable the sd bus voltage & card detect state is not stable, then host controller will disable the sd bus voltage. In case of warm/subsystem reboot, due to unstable card detect state host controller is disabling the sd bus voltage to sd card causing sd card timeout error. So we wait for a maximum of 1000msec to get the card detect state stable before we enable the sd bus voltage. This current fix is workaround for now, this needs to be analysed further. Zynqmp platform should behave the same as Versal, but we did not encounter this issue as of now. So we are fixing it for Versal only. Signed-off-by: T Karthik Reddy <t.karthik.reddy@xilinx.com> Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@xilinx.com> Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com>
-rw-r--r--drivers/mmc/zynq_sdhci.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/mmc/zynq_sdhci.c b/drivers/mmc/zynq_sdhci.c
index 9a1693940a7..4a877b4ce8c 100644
--- a/drivers/mmc/zynq_sdhci.c
+++ b/drivers/mmc/zynq_sdhci.c
@@ -776,6 +776,25 @@ static int arasan_sdhci_probe(struct udevice *dev)
return ret;
upriv->mmc = host->mmc;
+ /*
+ * WORKAROUND: Versal platforms have an issue with card detect state.
+ * Due to this, host controller is switching off voltage to sd card
+ * causing sd card timeout error. Workaround this by adding a wait for
+ * 1000msec till the card detect state gets stable.
+ */
+ if (IS_ENABLED(CONFIG_ARCH_VERSAL)) {
+ u32 timeout = 1000;
+
+ while (((sdhci_readl(host, SDHCI_PRESENT_STATE) &
+ SDHCI_CARD_STATE_STABLE) == 0) && timeout--) {
+ mdelay(1);
+ }
+ if (!timeout) {
+ dev_err(dev, "Sdhci card detect state not stable\n");
+ return -ETIMEDOUT;
+ }
+ }
+
return sdhci_probe(dev);
}