[PATCH 2/3] tpm_crb: encapsulate crb_wait_for_reg_32

From: Jarkko Sakkinen
Date: Tue Oct 11 2016 - 05:26:30 EST


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

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
---
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 c34318b..45f53c2 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -121,6 +121,25 @@ 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
*
@@ -138,27 +157,14 @@ 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_t->ctrl_req);
-
- start = ktime_get();
- stop = ktime_add(start, ms_to_ktime(TPM2_TIMEOUT_C));
- do {
- req = ioread32(&priv->regs_t->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_t->ctrl_req) & CRB_CTRL_REQ_CMD_READY) {
+ if (!crb_wait_for_reg_32(&priv->regs_t->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