From 5a885c52cfe6e5491fb7ce1d93d1a3d8f6fd6da9 Mon Sep 17 00:00:00 2001
From: Rander Wang <rander.wang@intel.com>
Date: Tue, 17 Mar 2020 11:33:15 -0500
Subject: [PATCH] soundwire: cadence: add interface to check clock status
Git-commit: 5a885c52cfe6e5491fb7ce1d93d1a3d8f6fd6da9
Patch-mainline: v5.7-rc1
References: jsc#SLE-16518

If master is in clock stop state, driver can't modify registers
in master except the registers for clock stop setting.

Signed-off-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200317163329.25501-4-pierre-louis.bossart@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/soundwire/cadence_master.c | 11 +++++++++++
 drivers/soundwire/cadence_master.h |  2 ++
 2 files changed, 13 insertions(+)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index 941809ea00a8..1bfdc1d4fcb1 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -1207,6 +1207,17 @@ static const struct sdw_master_port_ops cdns_port_ops = {
 	.dpn_port_enable_ch = cdns_port_enable,
 };
 
+/**
+ * sdw_cdns_is_clock_stop: Check clock status
+ *
+ * @cdns: Cadence instance
+ */
+bool sdw_cdns_is_clock_stop(struct sdw_cdns *cdns)
+{
+	return !!(cdns_readl(cdns, CDNS_MCP_STAT) & CDNS_MCP_STAT_CLK_STOP);
+}
+EXPORT_SYMBOL(sdw_cdns_is_clock_stop);
+
 /**
  * sdw_cdns_probe() - Cadence probe routine
  * @cdns: Cadence instance
diff --git a/drivers/soundwire/cadence_master.h b/drivers/soundwire/cadence_master.h
index 44e802bba702..691faa386889 100644
--- a/drivers/soundwire/cadence_master.h
+++ b/drivers/soundwire/cadence_master.h
@@ -144,6 +144,8 @@ int sdw_cdns_pdi_init(struct sdw_cdns *cdns,
 int sdw_cdns_exit_reset(struct sdw_cdns *cdns);
 int sdw_cdns_enable_interrupt(struct sdw_cdns *cdns, bool state);
 
+bool sdw_cdns_is_clock_stop(struct sdw_cdns *cdns);
+
 #ifdef CONFIG_DEBUG_FS
 void sdw_cdns_debugfs_init(struct sdw_cdns *cdns, struct dentry *root);
 #endif
-- 
2.16.4