[PATCH v2 01/14] soundwire: mipi_disco: add MIPI-specific property_read_bool() helpers

[Bard Liao]

From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>

The existing device/fwnode_property_read_bool() helpers only check if
the property is present.

The MIPI DisCo for SoundWire specification allows properties to be
exposed with a value of 'false'. Using the standard helpers to
retrieve the MIPI-defined properties causes all kinds of logical
inversions leading to loss of functionality - such as jack detection
in clock-stop mode broken when the device properties are read in
Realtek codec drivers.

This patch adds new MIPI/SoundWire helpers which first check if the
property is present, and then return the actual value extracted from
platform firmware.

Modifying the default property handling was considered as a possible
solution, but it could lead to other types of logical inversions
breaking 'working' setups. Andy Shevchenko also pointed out that DT
keeps values in the BE32 format, it's probably best to avoid
endianness complications.

The path of least resistance was chosen, with MIPI-specific helpers
which can be tested and with no side effects outside of the SoundWire
subsystem.

Closes: https://github.com/thesofproject/linux/issues/5129
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
---
 drivers/soundwire/mipi_disco.c | 50 ++++++++++++++++++++++++----------
 1 file changed, 35 insertions(+), 15 deletions(-)

diff --git a/drivers/soundwire/mipi_disco.c b/drivers/soundwire/mipi_disco.c
index e5d9df26d4dc..fdab3d4a1379 100644
--- a/drivers/soundwire/mipi_disco.c
+++ b/drivers/soundwire/mipi_disco.c
@@ -23,6 +23,26 @@
 #include <linux/soundwire/sdw.h>
 #include "bus.h"
 
+static bool mipi_fwnode_property_read_bool(const struct fwnode_handle *fwnode,
+					   const char *propname)
+{
+	int ret;
+	u8 val;
+
+	if (!fwnode_property_present(fwnode, propname))
+		return false;
+	ret = fwnode_property_read_u8_array(fwnode, propname, &val, 1);
+	if (ret < 0)
+		return false;
+	return !!val;
+}
+
+static bool mipi_device_property_read_bool(const struct device *dev,
+					   const char *propname)
+{
+	return mipi_fwnode_property_read_bool(dev_fwnode(dev), propname);
+}
+
 /**
  * sdw_master_read_prop() - Read Master properties
  * @bus: SDW bus instance
@@ -48,11 +68,11 @@ int sdw_master_read_prop(struct sdw_bus *bus)
 		return -EIO;
 	}
 
-	if (fwnode_property_read_bool(link,
+	if (mipi_fwnode_property_read_bool(link,
 				      "mipi-sdw-clock-stop-mode0-supported"))
 		prop->clk_stop_modes |= BIT(SDW_CLK_STOP_MODE0);
 
-	if (fwnode_property_read_bool(link,
+	if (mipi_fwnode_property_read_bool(link,
 				      "mipi-sdw-clock-stop-mode1-supported"))
 		prop->clk_stop_modes |= BIT(SDW_CLK_STOP_MODE1);
 
@@ -114,7 +134,7 @@ int sdw_master_read_prop(struct sdw_bus *bus)
 	fwnode_property_read_u32(link, "mipi-sdw-default-frame-col-size",
 				 &prop->default_col);
 
-	prop->dynamic_frame =  fwnode_property_read_bool(link,
+	prop->dynamic_frame =  mipi_fwnode_property_read_bool(link,
 			"mipi-sdw-dynamic-frame-shape");
 
 	fwnode_property_read_u32(link, "mipi-sdw-command-error-threshold",
@@ -153,13 +173,13 @@ static int sdw_slave_read_dp0(struct sdw_slave *slave,
 				dp0->words, dp0->num_words);
 	}
 
-	dp0->BRA_flow_controlled = fwnode_property_read_bool(port,
+	dp0->BRA_flow_controlled = mipi_fwnode_property_read_bool(port,
 				"mipi-sdw-bra-flow-controlled");
 
-	dp0->simple_ch_prep_sm = fwnode_property_read_bool(port,
+	dp0->simple_ch_prep_sm = mipi_fwnode_property_read_bool(port,
 				"mipi-sdw-simplified-channel-prepare-sm");
 
-	dp0->imp_def_interrupts = fwnode_property_read_bool(port,
+	dp0->imp_def_interrupts = mipi_fwnode_property_read_bool(port,
 				"mipi-sdw-imp-def-dp0-interrupts-supported");
 
 	return 0;
@@ -220,7 +240,7 @@ static int sdw_slave_read_dpn(struct sdw_slave *slave,
 					 "mipi-sdw-max-grouping-supported",
 					 &dpn[i].max_grouping);
 
-		dpn[i].simple_ch_prep_sm = fwnode_property_read_bool(node,
+		dpn[i].simple_ch_prep_sm = mipi_fwnode_property_read_bool(node,
 				"mipi-sdw-simplified-channelprepare-sm");
 
 		fwnode_property_read_u32(node,
@@ -278,7 +298,7 @@ static int sdw_slave_read_dpn(struct sdw_slave *slave,
 		fwnode_property_read_u32(node, "mipi-sdw-max-async-buffer",
 					 &dpn[i].max_async_buffer);
 
-		dpn[i].block_pack_mode = fwnode_property_read_bool(node,
+		dpn[i].block_pack_mode = mipi_fwnode_property_read_bool(node,
 				"mipi-sdw-block-packing-mode");
 
 		fwnode_property_read_u32(node, "mipi-sdw-port-encoding-type",
@@ -308,19 +328,19 @@ int sdw_slave_read_prop(struct sdw_slave *slave)
 	device_property_read_u32(dev, "mipi-sdw-sw-interface-revision",
 				 &prop->mipi_revision);
 
-	prop->wake_capable = device_property_read_bool(dev,
+	prop->wake_capable = mipi_device_property_read_bool(dev,
 				"mipi-sdw-wake-up-unavailable");
 	prop->wake_capable = !prop->wake_capable;
 
-	prop->test_mode_capable = device_property_read_bool(dev,
+	prop->test_mode_capable = mipi_device_property_read_bool(dev,
 				"mipi-sdw-test-mode-supported");
 
 	prop->clk_stop_mode1 = false;
-	if (device_property_read_bool(dev,
+	if (mipi_device_property_read_bool(dev,
 				"mipi-sdw-clock-stop-mode1-supported"))
 		prop->clk_stop_mode1 = true;
 
-	prop->simple_clk_stop_capable = device_property_read_bool(dev,
+	prop->simple_clk_stop_capable = mipi_device_property_read_bool(dev,
 			"mipi-sdw-simplified-clockstopprepare-sm-supported");
 
 	device_property_read_u32(dev, "mipi-sdw-clockstopprepare-timeout",
@@ -333,13 +353,13 @@ int sdw_slave_read_prop(struct sdw_slave *slave)
 			"mipi-sdw-clockstopprepare-hard-reset-behavior",
 			&prop->reset_behave);
 
-	prop->high_PHY_capable = device_property_read_bool(dev,
+	prop->high_PHY_capable = mipi_device_property_read_bool(dev,
 			"mipi-sdw-highPHY-capable");
 
-	prop->paging_support = device_property_read_bool(dev,
+	prop->paging_support = mipi_device_property_read_bool(dev,
 			"mipi-sdw-paging-support");
 
-	prop->bank_delay_support = device_property_read_bool(dev,
+	prop->bank_delay_support = mipi_device_property_read_bool(dev,
 			"mipi-sdw-bank-delay-support");
 
 	device_property_read_u32(dev,
-- 
2.43.0