[PATCH RFC 2/3] tpm_crb: encapsulate crb_wait_for_reg_32

[Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>]

Encapsulated crb_wait_for_reg32() so that state changes in other CRB
registers than CTRL_REQ_X can be waited.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 drivers/char/tpm/tpm_crb.c | 40 +++++++++++++++++++++++-----------------
 1 file changed, 23 insertions(+), 17 deletions(-)

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 3d021e6..ffd3a6c 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -118,6 +118,25 @@ static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv)
 	return 0;
 }
 
+static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
+				unsigned long timeout)
+{
+	ktime_t start;
+	ktime_t stop;
+
+	start = ktime_get();
+	stop = ktime_add(start, ms_to_ktime(timeout));
+
+	do {
+		if ((ioread32(reg) & mask) == value)
+			return true;
+
+		usleep_range(50, 100);
+	} while (ktime_before(ktime_get(), stop));
+
+	return false;
+}
+
 /**
  * crb_cmd_ready - request tpm crb device to enter ready state
  *
@@ -135,27 +154,14 @@ static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv)
 static int __maybe_unused crb_cmd_ready(struct device *dev,
 					struct crb_priv *priv)
 {
-	ktime_t stop, start;
-	u32 req;
-
 	if (priv->flags & CRB_FL_ACPI_START)
 		return 0;
 
 	iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->regs->ctrl_req);
-
-	start = ktime_get();
-	stop = ktime_add(start, ms_to_ktime(TPM2_TIMEOUT_C));
-	do {
-		req = ioread32(&priv->regs->ctrl_req);
-		if (!(req & CRB_CTRL_REQ_CMD_READY)) {
-			dev_dbg(dev, "cmdReady in %lld usecs\n",
-				ktime_to_us(ktime_sub(ktime_get(), start)));
-			return 0;
-		}
-		usleep_range(50, 100);
-	} while (ktime_before(ktime_get(), stop));
-
-	if (ioread32(&priv->regs->ctrl_req) & CRB_CTRL_REQ_CMD_READY) {
+	if (!crb_wait_for_reg_32(&priv->regs->ctrl_req,
+				 CRB_CTRL_REQ_CMD_READY /* mask */,
+				 0, /* value */
+				 TPM2_TIMEOUT_C)) {
 		dev_warn(dev, "cmdReady timed out\n");
 		return -ETIME;
 	}
-- 
2.7.4