[PATCH v3 1/7] mmc: cqhci: Provide helper for resetting both SDHCI and CQHCI

[Brian Norris]

Several SDHCI drivers need to deactivate command queueing in their reset
hook (see sdhci_cqhci_reset() / sdhci-pci-core.c, for example), and
several more are coming.

Those reset implementations have some small subtleties (e.g., ordering
of initialization of SDHCI vs. CQHCI might leave us resetting with a
NULL ->cqe_private), and are often identical across different host
drivers.

We also don't want to force a dependency between SDHCI and CQHCI, or
vice versa; non-SDHCI drivers use CQHCI, and SDHCI drivers might support
command queueing through some other means.

So, implement a small helper, to avoid repeating the same mistakes in
different drivers. Simply stick it in a header, because it's so small it
doesn't deserve its own module right now, and inlining to each driver is
pretty reasonable.

This is marked for -stable, as it is an important prerequisite patch for
several SDHCI controller bugfixes that follow.

Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
---

Changes in v3:
 - New in v3 (replacing a simple 'cqe_private == NULL' patch in v2)

 drivers/mmc/host/sdhci-cqhci.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 drivers/mmc/host/sdhci-cqhci.h

diff --git a/drivers/mmc/host/sdhci-cqhci.h b/drivers/mmc/host/sdhci-cqhci.h
new file mode 100644
index 000000000000..270ab1f1de3c
--- /dev/null
+++ b/drivers/mmc/host/sdhci-cqhci.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2022 The Chromium OS Authors
+ *
+ * Support that applies to the combination of SDHCI and CQHCI, while not
+ * expressing a dependency between the two modules.
+ */
+
+#ifndef __MMC_HOST_SDHCI_CQHCI_H__
+#define __MMC_HOST_SDHCI_CQHCI_H__
+
+#include "cqhci.h"
+#include "sdhci.h"
+
+static inline void sdhci_and_cqhci_reset(struct sdhci_host *host, u8 mask)
+{
+	if ((host->mmc->caps2 & MMC_CAP2_CQE) && (mask & SDHCI_RESET_ALL) &&
+	    host->mmc->cqe_private)
+		cqhci_deactivate(host->mmc);
+
+	sdhci_reset(host, mask);
+}
+
+
+#endif /* __MMC_HOST_SDHCI_CQHCI_H__ */
-- 
2.38.0.135.g90850a2211-goog