[PATCHv2 03/11] soc: ti: omap-prm: poll for reset complete during de-assert

[Tero Kristo <t-kristo@ti.com>]

Poll for reset completion status during de-assertion of reset, otherwise
the IP in question might be accessed before it has left reset properly.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
---
 drivers/soc/ti/omap_prm.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/soc/ti/omap_prm.c b/drivers/soc/ti/omap_prm.c
index fd5c431f8736..afeb70761b27 100644
--- a/drivers/soc/ti/omap_prm.c
+++ b/drivers/soc/ti/omap_prm.c
@@ -127,6 +127,7 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev,
 	u32 v;
 	int st_bit;
 	bool has_rstst;
+	int timeout = 0;
 
 	if (!_is_valid_reset(reset, id))
 		return -EINVAL;
@@ -153,6 +154,25 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev,
 	v &= ~(1 << id);
 	writel_relaxed(v, reset->prm->base + reset->prm->data->rstctrl);
 
+	if (!has_rstst)
+		return 0;
+
+	/* wait for the status to be set */
+	while (1) {
+		v = readl_relaxed(reset->prm->base + reset->prm->data->rstst);
+		v &= 1 << st_bit;
+		if (v)
+			break;
+		timeout++;
+		if (timeout > OMAP_RESET_MAX_WAIT) {
+			pr_err("%s: timedout waiting for %s:%lu\n", __func__,
+			       dev_name(rcdev->dev), id);
+			return -EBUSY;
+		}
+
+		udelay(1);
+	}
+
 	return 0;
 }
 
-- 
2.17.1

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