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[3/8] soc: ti: omap-prm: poll for reset complete during de-assert

Message ID 1565164139-21886-4-git-send-email-t-kristo@ti.com
State New
Headers show
Series soc: ti: Add OMAP PRM driver | expand

Commit Message

Tero Kristo Aug. 7, 2019, 7:48 a.m. UTC 
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 | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

-- 
1.9.1

--
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
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Patch

diff --git a/drivers/soc/ti/omap_prm.c b/drivers/soc/ti/omap_prm.c
index 7c89eb8..d412af3 100644
--- a/drivers/soc/ti/omap_prm.c
+++ b/drivers/soc/ti/omap_prm.c
@@ -107,6 +107,7 @@  static int omap_reset_deassert(struct reset_controller_dev *rcdev,
 	u32 v;
 	int st_bit = id;
 	bool has_rstst;
+	int timeout = 0;
 
 	/* check the current status to avoid de-asserting the line twice */
 	v = readl_relaxed(reset->prm->base + reset->prm->data->rstctl);
@@ -129,6 +130,22 @@  static int omap_reset_deassert(struct reset_controller_dev *rcdev,
 	v &= ~(1 << id);
 	writel_relaxed(v, reset->prm->base + reset->prm->data->rstctl);
 
+	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)
+			return -EBUSY;
+
+		udelay(1);
+	}
+
 	return 0;
 }