[PATCH 0/3] soundwire: debugfs support for 5.4

[PATCH 0/3] soundwire: debugfs support for 5.4

[Pierre-Louis Bossart]

This patchset enables debugfs support and corrects all the feedback
provided on an earlier RFC ('soundwire: updates for 5.4')

There is one remaining hard-coded value in intel.c that will need to
be fixed in a follow-up patchset not specific to debugfs: we need to
remove hard-coded Intel-specific configurations from cadence_master.c
(PDI offsets, etc).

Changes since RFC (Feedback from GKH, Vinod, Guennadi, Cezary, Sanyog):
removed error checks
used DEFINE_SHOW_ATTRIBUTE and seq_file
fixed copyright dates
fixed SPDX license info to use GPL2.0 only
fixed Makefile to include debugfs only if CONFIG_DEBUG_FS is selected
used static inlines for fallback compilation
removed intermediate variables
removed hard-coded constants in loops (used registers offsets and
hardware capabilities)
squashed patch 3

Pierre-Louis Bossart (3):
  soundwire: add debugfs support
  soundwire: cadence_master: add debugfs register dump
  soundwire: intel: add debugfs register dump

 drivers/soundwire/Makefile         |   5 +
 drivers/soundwire/bus.c            |   6 ++
 drivers/soundwire/bus.h            |  24 +++++
 drivers/soundwire/bus_type.c       |   3 +
 drivers/soundwire/cadence_master.c | 104 ++++++++++++++++++++
 drivers/soundwire/cadence_master.h |   2 +
 drivers/soundwire/debugfs.c        | 151 +++++++++++++++++++++++++++++
 drivers/soundwire/intel.c          | 114 ++++++++++++++++++++++
 drivers/soundwire/slave.c          |   1 +
 include/linux/soundwire/sdw.h      |   4 +
 10 files changed, 414 insertions(+)
 create mode 100644 drivers/soundwire/debugfs.c

-- 
2.20.1

[PATCH 1/3] soundwire: add debugfs support

[Pierre-Louis Bossart]

Add base debugfs mechanism for SoundWire bus by creating soundwire
root and master-N and slave-x hierarchy.

Also add SDW Slave SCP, DP0 and DP-N register debug file.

Registers not implemented will print as "XX"

Credits: this patch is based on an earlier internal contribution by
Vinod Koul, Sanyog Kale, Shreyas Nc and Hardik Shah.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
---
 drivers/soundwire/Makefile    |   5 ++
 drivers/soundwire/bus.c       |   6 ++
 drivers/soundwire/bus.h       |  24 ++++++
 drivers/soundwire/bus_type.c  |   3 +
 drivers/soundwire/debugfs.c   | 151 ++++++++++++++++++++++++++++++++++
 drivers/soundwire/slave.c     |   1 +
 include/linux/soundwire/sdw.h |   4 +
 7 files changed, 194 insertions(+)
 create mode 100644 drivers/soundwire/debugfs.c

diff --git a/drivers/soundwire/Makefile b/drivers/soundwire/Makefile
index fd99a831b92a..05d4cb9ef7d6 100644
--- a/drivers/soundwire/Makefile
+++ b/drivers/soundwire/Makefile
@@ -5,6 +5,11 @@
 
 #Bus Objs
 soundwire-bus-objs := bus_type.o bus.o slave.o mipi_disco.o stream.o
+
+ifdef CONFIG_DEBUG_FS
+soundwire-bus-objs += debugfs.o
+endif
+
 obj-$(CONFIG_SOUNDWIRE_BUS) += soundwire-bus.o
 
 #Cadence Objs
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 49f64b2115b9..89d5f1537d9b 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -49,6 +49,8 @@ int sdw_add_bus_master(struct sdw_bus *bus)
 		}
 	}
 
+	bus->debugfs = sdw_bus_debugfs_init(bus);
+
 	/*
 	 * Device numbers in SoundWire are 0 through 15. Enumeration device
 	 * number (0), Broadcast device number (15), Group numbers (12 and
@@ -109,6 +111,8 @@ static int sdw_delete_slave(struct device *dev, void *data)
 	struct sdw_slave *slave = dev_to_sdw_dev(dev);
 	struct sdw_bus *bus = slave->bus;
 
+	sdw_slave_debugfs_exit(slave->debugfs);
+
 	mutex_lock(&bus->bus_lock);
 
 	if (slave->dev_num) /* clear dev_num if assigned */
@@ -130,6 +134,8 @@ static int sdw_delete_slave(struct device *dev, void *data)
 void sdw_delete_bus_master(struct sdw_bus *bus)
 {
 	device_for_each_child(bus->dev, NULL, sdw_delete_slave);
+
+	sdw_bus_debugfs_exit(bus->debugfs);
 }
 EXPORT_SYMBOL(sdw_delete_bus_master);
 
diff --git a/drivers/soundwire/bus.h b/drivers/soundwire/bus.h
index 3048ca153f22..648436a995a3 100644
--- a/drivers/soundwire/bus.h
+++ b/drivers/soundwire/bus.h
@@ -18,6 +18,30 @@ static inline int sdw_acpi_find_slaves(struct sdw_bus *bus)
 void sdw_extract_slave_id(struct sdw_bus *bus,
 			  u64 addr, struct sdw_slave_id *id);
 
+#ifdef CONFIG_DEBUG_FS
+struct dentry *sdw_bus_debugfs_init(struct sdw_bus *bus);
+void sdw_bus_debugfs_exit(struct dentry *d);
+struct dentry *sdw_slave_debugfs_init(struct sdw_slave *slave);
+void sdw_slave_debugfs_exit(struct dentry *d);
+void sdw_debugfs_init(void);
+void sdw_debugfs_exit(void);
+#else
+static inline struct dentry *sdw_bus_debugfs_init(struct sdw_bus *bus)
+{ return NULL; }
+
+static inline void sdw_bus_debugfs_exit(struct dentry *d) {}
+
+static inline struct dentry *sdw_slave_debugfs_init(struct sdw_slave *slave)
+{ return NULL; }
+
+static inline void sdw_slave_debugfs_exit(struct dentry *d) {}
+
+static inline void sdw_debugfs_init(void) {}
+
+static inline void sdw_debugfs_exit(void) {}
+
+#endif
+
 enum {
 	SDW_MSG_FLAG_READ = 0,
 	SDW_MSG_FLAG_WRITE,
diff --git a/drivers/soundwire/bus_type.c b/drivers/soundwire/bus_type.c
index 2655602f0cfb..4a465f55039f 100644
--- a/drivers/soundwire/bus_type.c
+++ b/drivers/soundwire/bus_type.c
@@ -6,6 +6,7 @@
 #include <linux/pm_domain.h>
 #include <linux/soundwire/sdw.h>
 #include <linux/soundwire/sdw_type.h>
+#include "bus.h"
 
 /**
  * sdw_get_device_id - find the matching SoundWire device id
@@ -177,11 +178,13 @@ EXPORT_SYMBOL_GPL(sdw_unregister_driver);
 
 static int __init sdw_bus_init(void)
 {
+	sdw_debugfs_init();
 	return bus_register(&sdw_bus_type);
 }
 
 static void __exit sdw_bus_exit(void)
 {
+	sdw_debugfs_exit();
 	bus_unregister(&sdw_bus_type);
 }
 
diff --git a/drivers/soundwire/debugfs.c b/drivers/soundwire/debugfs.c
new file mode 100644
index 000000000000..200eb98ec99b
--- /dev/null
+++ b/drivers/soundwire/debugfs.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright(c) 2017-2019 Intel Corporation.
+
+#include <linux/device.h>
+#include <linux/debugfs.h>
+#include <linux/mod_devicetable.h>
+#include <linux/slab.h>
+#include <linux/soundwire/sdw.h>
+#include <linux/soundwire/sdw_registers.h>
+#include "bus.h"
+
+static struct dentry *sdw_debugfs_root;
+
+struct dentry *sdw_bus_debugfs_init(struct sdw_bus *bus)
+{
+	char name[16];
+
+	if (!sdw_debugfs_root)
+		return NULL;
+
+	/* create the debugfs master-N */
+	snprintf(name, sizeof(name), "master-%d", bus->link_id);
+	return debugfs_create_dir(name, sdw_debugfs_root);
+}
+
+void sdw_bus_debugfs_exit(struct dentry *d)
+{
+	debugfs_remove_recursive(d);
+}
+
+#define RD_BUF (3 * PAGE_SIZE)
+
+static ssize_t sdw_sprintf(struct sdw_slave *slave,
+			   char *buf, size_t pos, unsigned int reg)
+{
+	int value;
+
+	value = sdw_read(slave, reg);
+
+	if (value < 0)
+		return scnprintf(buf + pos, RD_BUF - pos, "%3x\tXX\n", reg);
+	else
+		return scnprintf(buf + pos, RD_BUF - pos,
+				"%3x\t%2x\n", reg, value);
+}
+
+static int sdw_slave_reg_show(struct seq_file *s_file, void *data)
+{
+	struct sdw_slave *slave = s_file->private;
+	char *buf;
+	ssize_t ret;
+	int i, j;
+
+	buf = kzalloc(RD_BUF, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = scnprintf(buf, RD_BUF, "Register  Value\n");
+
+	/* DP0 non-banked registers */
+	ret += scnprintf(buf + ret, RD_BUF - ret, "\nDP0\n");
+	for (i = SDW_DP0_INT; i <= SDW_DP0_PREPARECTRL; i++)
+		ret += sdw_sprintf(slave, buf, ret, i);
+
+	/* DP0 Bank 0 registers */
+	ret += scnprintf(buf + ret, RD_BUF - ret, "Bank0\n");
+	ret += sdw_sprintf(slave, buf, ret, SDW_DP0_CHANNELEN);
+	for (i = SDW_DP0_SAMPLECTRL1; i <= SDW_DP0_LANECTRL; i++)
+		ret += sdw_sprintf(slave, buf, ret, i);
+
+	/* DP0 Bank 1 registers */
+	ret += scnprintf(buf + ret, RD_BUF - ret, "Bank1\n");
+	ret += sdw_sprintf(slave, buf, ret,
+			SDW_DP0_CHANNELEN + SDW_BANK1_OFFSET);
+	for (i = SDW_DP0_SAMPLECTRL1 + SDW_BANK1_OFFSET;
+			i <= SDW_DP0_LANECTRL + SDW_BANK1_OFFSET; i++)
+		ret += sdw_sprintf(slave, buf, ret, i);
+
+	/* SCP registers */
+	ret += scnprintf(buf + ret, RD_BUF - ret, "\nSCP\n");
+	for (i = SDW_SCP_INT1; i <= SDW_SCP_BANKDELAY; i++)
+		ret += sdw_sprintf(slave, buf, ret, i);
+	for (i = SDW_SCP_DEVID_0; i <= SDW_SCP_DEVID_5; i++)
+		ret += sdw_sprintf(slave, buf, ret, i);
+
+	/*
+	 * SCP Bank 0/1 registers are read-only and cannot be
+	 * retrieved from the Slave. The Master typically keeps track
+	 * of the current frame size so the information can be found
+	 * in other places
+	 */
+
+	/* DP1..14 registers */
+	for (i = 1; SDW_VALID_PORT_RANGE(i); i++) {
+
+		/* DPi registers */
+		ret += scnprintf(buf + ret, RD_BUF - ret, "\nDP%d\n", i);
+		for (j = SDW_DPN_INT(i); j <= SDW_DPN_PREPARECTRL(i); j++)
+			ret += sdw_sprintf(slave, buf, ret, j);
+
+		/* DPi Bank0 registers */
+		ret += scnprintf(buf + ret, RD_BUF - ret, "Bank0\n");
+		for (j = SDW_DPN_CHANNELEN_B0(i);
+		     j <= SDW_DPN_LANECTRL_B0(i); j++)
+			ret += sdw_sprintf(slave, buf, ret, j);
+
+		/* DPi Bank1 registers */
+		ret += scnprintf(buf + ret, RD_BUF - ret, "Bank1\n");
+		for (j = SDW_DPN_CHANNELEN_B1(i);
+		     j <= SDW_DPN_LANECTRL_B1(i); j++)
+			ret += sdw_sprintf(slave, buf, ret, j);
+	}
+
+	seq_printf(s_file, "%s", buf);
+	kfree(buf);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(sdw_slave_reg);
+
+struct dentry *sdw_slave_debugfs_init(struct sdw_slave *slave)
+{
+	struct dentry *master;
+	struct dentry *d;
+	char name[32];
+
+	master = slave->bus->debugfs;
+
+	/* create the debugfs slave-name */
+	snprintf(name, sizeof(name), "%s", dev_name(&slave->dev));
+	d = debugfs_create_dir(name, master);
+
+	debugfs_create_file("registers", 0400, d, slave, &sdw_slave_reg_fops);
+
+	return d;
+}
+
+void sdw_slave_debugfs_exit(struct dentry *d)
+{
+	debugfs_remove_recursive(d);
+}
+
+void sdw_debugfs_init(void)
+{
+	sdw_debugfs_root = debugfs_create_dir("soundwire", NULL);
+}
+
+void sdw_debugfs_exit(void)
+{
+	debugfs_remove_recursive(sdw_debugfs_root);
+}
diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c
index f39a5815e25d..34d8bb995f45 100644
--- a/drivers/soundwire/slave.c
+++ b/drivers/soundwire/slave.c
@@ -56,6 +56,7 @@ static int sdw_slave_add(struct sdw_bus *bus,
 		mutex_unlock(&bus->bus_lock);
 		put_device(&slave->dev);
 	}
+	slave->debugfs = sdw_slave_debugfs_init(slave);
 
 	return ret;
 }
diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h
index 3b231472464a..a49028e9d666 100644
--- a/include/linux/soundwire/sdw.h
+++ b/include/linux/soundwire/sdw.h
@@ -544,6 +544,7 @@ struct sdw_slave_ops {
  * @bus: Bus handle
  * @ops: Slave callback ops
  * @prop: Slave properties
+ * @debugfs: Slave debugfs
  * @node: node for bus list
  * @port_ready: Port ready completion flag for each Slave port
  * @dev_num: Device Number assigned by Bus
@@ -555,6 +556,7 @@ struct sdw_slave {
 	struct sdw_bus *bus;
 	const struct sdw_slave_ops *ops;
 	struct sdw_slave_prop prop;
+	struct dentry *debugfs;
 	struct list_head node;
 	struct completion *port_ready;
 	u16 dev_num;
@@ -731,6 +733,7 @@ struct sdw_master_ops {
  * @m_rt_list: List of Master instance of all stream(s) running on Bus. This
  * is used to compute and program bus bandwidth, clock, frame shape,
  * transport and port parameters
+ * @debugfs: Bus debugfs
  * @defer_msg: Defer message
  * @clk_stop_timeout: Clock stop timeout computed
  * @bank_switch_timeout: Bank switch timeout computed
@@ -750,6 +753,7 @@ struct sdw_bus {
 	struct sdw_bus_params params;
 	struct sdw_master_prop prop;
 	struct list_head m_rt_list;
+	struct dentry *debugfs;
 	struct sdw_defer defer_msg;
 	unsigned int clk_stop_timeout;
 	u32 bank_switch_timeout;
-- 
2.20.1

[PATCH 2/3] soundwire: cadence_master: add debugfs register dump

[Pierre-Louis Bossart]

Add debugfs file to dump the Cadence master registers

Credits: this patch is based on an earlier internal contribution by
Vinod Koul, Sanyog Kale, Shreyas Nc and Hardik Shah.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
---
 drivers/soundwire/cadence_master.c | 104 +++++++++++++++++++++++++++++
 drivers/soundwire/cadence_master.h |   2 +
 2 files changed, 106 insertions(+)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index 665632dbdeb5..4c65b78adcf9 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -8,6 +8,7 @@
 
 #include <linux/delay.h>
 #include <linux/device.h>
+#include <linux/debugfs.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/module.h>
@@ -223,6 +224,109 @@ static int cdns_clear_bit(struct sdw_cdns *cdns, int offset, u32 value)
 	return -EAGAIN;
 }
 
+/*
+ * debugfs
+ */
+
+#define RD_BUF (2 * PAGE_SIZE)
+
+static ssize_t cdns_sprintf(struct sdw_cdns *cdns,
+			    char *buf, size_t pos, unsigned int reg)
+{
+	return scnprintf(buf + pos, RD_BUF - pos,
+			 "%4x\t%8x\n", reg, cdns_readl(cdns, reg));
+}
+
+static int cdns_reg_show(struct seq_file *s, void *data)
+{
+	struct sdw_cdns *cdns = s->private;
+	char *buf;
+	ssize_t ret;
+	int num_ports;
+	int i, j;
+
+	buf = kzalloc(RD_BUF, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = scnprintf(buf, RD_BUF, "Register  Value\n");
+	ret += scnprintf(buf + ret, RD_BUF - ret, "\nMCP Registers\n");
+	/* 8 MCP registers */
+	for (i = CDNS_MCP_CONFIG; i <= CDNS_MCP_PHYCTRL; i += sizeof(u32))
+		ret += cdns_sprintf(cdns, buf, ret, i);
+
+	ret += scnprintf(buf + ret, RD_BUF - ret,
+			 "\nStatus & Intr Registers\n");
+	/* 13 Status & Intr registers (offsets 0x70 and 0x74 not defined) */
+	for (i = CDNS_MCP_STAT; i <=  CDNS_MCP_FIFOSTAT; i += sizeof(u32))
+		ret += cdns_sprintf(cdns, buf, ret, i);
+
+	ret += scnprintf(buf + ret, RD_BUF - ret,
+			 "\nSSP & Clk ctrl Registers\n");
+	ret += cdns_sprintf(cdns, buf, ret, CDNS_MCP_SSP_CTRL0);
+	ret += cdns_sprintf(cdns, buf, ret, CDNS_MCP_SSP_CTRL1);
+	ret += cdns_sprintf(cdns, buf, ret, CDNS_MCP_CLK_CTRL0);
+	ret += cdns_sprintf(cdns, buf, ret, CDNS_MCP_CLK_CTRL1);
+
+	ret += scnprintf(buf + ret, RD_BUF - ret,
+			 "\nDPn B0 Registers\n");
+
+	/*
+	 * in sdw_cdns_pdi_init() we filter out the Bulk PDIs,
+	 * so the indices need to be corrected again
+	 */
+	num_ports = cdns->num_ports + CDNS_PCM_PDI_OFFSET;
+
+	for (i = 0; i < num_ports; i++) {
+		ret += scnprintf(buf + ret, RD_BUF - ret,
+				 "\nDP-%d\n", i);
+		for (j = CDNS_DPN_B0_CONFIG(i);
+		     j < CDNS_DPN_B0_ASYNC_CTRL(i); j += sizeof(u32))
+			ret += cdns_sprintf(cdns, buf, ret, j);
+	}
+
+	ret += scnprintf(buf + ret, RD_BUF - ret,
+			 "\nDPn B1 Registers\n");
+	for (i = 0; i < num_ports; i++) {
+		ret += scnprintf(buf + ret, RD_BUF - ret,
+				 "\nDP-%d\n", i);
+
+		for (j = CDNS_DPN_B1_CONFIG(i);
+		     j < CDNS_DPN_B1_ASYNC_CTRL(i); j += sizeof(u32))
+			ret += cdns_sprintf(cdns, buf, ret, j);
+	}
+
+	ret += scnprintf(buf + ret, RD_BUF - ret,
+			 "\nDPn Control Registers\n");
+	for (i = 0; i < num_ports; i++)
+		ret += cdns_sprintf(cdns, buf, ret,
+				CDNS_PORTCTRL + i * CDNS_PORT_OFFSET);
+
+	ret += scnprintf(buf + ret, RD_BUF - ret,
+			 "\nPDIn Config Registers\n");
+
+	/* number of PDI and ports is interchangeable */
+	for (i = 0; i < num_ports; i++)
+		ret += cdns_sprintf(cdns, buf, ret, CDNS_PDI_CONFIG(i));
+
+	seq_printf(s, "%s", buf);
+	kfree(buf);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(cdns_reg);
+
+/**
+ * sdw_cdns_debugfs_init() - Cadence debugfs init
+ * @cdns: Cadence instance
+ * @root: debugfs root
+ */
+void sdw_cdns_debugfs_init(struct sdw_cdns *cdns, struct dentry *root)
+{
+	debugfs_create_file("cdns-registers", 0400, root, cdns, &cdns_reg_fops);
+}
+EXPORT_SYMBOL_GPL(sdw_cdns_debugfs_init);
+
 /*
  * IO Calls
  */
diff --git a/drivers/soundwire/cadence_master.h b/drivers/soundwire/cadence_master.h
index fe2af62958b1..c0bf6ff00a44 100644
--- a/drivers/soundwire/cadence_master.h
+++ b/drivers/soundwire/cadence_master.h
@@ -163,6 +163,8 @@ int sdw_cdns_pdi_init(struct sdw_cdns *cdns,
 		      struct sdw_cdns_stream_config config);
 int sdw_cdns_enable_interrupt(struct sdw_cdns *cdns);
 
+void sdw_cdns_debugfs_init(struct sdw_cdns *cdns, struct dentry *root);
+
 int sdw_cdns_get_stream(struct sdw_cdns *cdns,
 			struct sdw_cdns_streams *stream,
 			u32 ch, u32 dir);
-- 
2.20.1

[PATCH 3/3] soundwire: intel: add debugfs register dump

[Pierre-Louis Bossart]

Add debugfs file to dump the Intel SoundWire registers

Credits: this patch is based on an earlier internal contribution by
Vinod Koul, Sanyog Kale, Shreyas Nc and Hardik Shah.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
---
 drivers/soundwire/intel.c | 114 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index c82ca4e13de7..9ae69dad1437 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/acpi.h>
+#include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
@@ -16,6 +17,7 @@
 #include <linux/soundwire/sdw.h>
 #include <linux/soundwire/sdw_intel.h>
 #include "cadence_master.h"
+#include "bus.h"
 #include "intel.h"
 
 /* Intel SHIM Registers Definition */
@@ -83,6 +85,7 @@
 
 /* Intel ALH Register definitions */
 #define SDW_ALH_STRMZCFG(x)		(0x000 + (0x4 * (x)))
+#define SDW_ALH_NUM_STREAMS		64
 
 #define SDW_ALH_STRMZCFG_DMAT_VAL	0x3
 #define SDW_ALH_STRMZCFG_DMAT		GENMASK(7, 0)
@@ -98,6 +101,7 @@ struct sdw_intel {
 	struct sdw_cdns cdns;
 	int instance;
 	struct sdw_intel_link_res *res;
+	struct dentry *fs;
 };
 
 #define cdns_to_intel(_cdns) container_of(_cdns, struct sdw_intel, cdns)
@@ -161,6 +165,113 @@ static int intel_set_bit(void __iomem *base, int offset, u32 value, u32 mask)
 	return -EAGAIN;
 }
 
+/*
+ * debugfs
+ */
+
+#define RD_BUF (2 * PAGE_SIZE)
+
+static ssize_t intel_sprintf(void __iomem *mem, bool l,
+			     char *buf, size_t pos, unsigned int reg)
+{
+	int value;
+
+	if (l)
+		value = intel_readl(mem, reg);
+	else
+		value = intel_readw(mem, reg);
+
+	return scnprintf(buf + pos, RD_BUF - pos, "%4x\t%4x\n", reg, value);
+}
+
+static int intel_reg_show(struct seq_file *s_file, void *data)
+{
+	struct sdw_intel *sdw = s_file->private;
+	void __iomem *s = sdw->res->shim;
+	void __iomem *a = sdw->res->alh;
+	char *buf;
+	ssize_t ret;
+	int i, j;
+	unsigned int links, reg;
+
+	buf = kzalloc(RD_BUF, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	links = intel_readl(s, SDW_SHIM_LCAP) & GENMASK(2, 0);
+
+	ret = scnprintf(buf, RD_BUF, "Register  Value\n");
+	ret += scnprintf(buf + ret, RD_BUF - ret, "\nShim\n");
+
+	for (i = 0; i < links; i++) {
+		reg = SDW_SHIM_LCAP + i * 4;
+		ret += intel_sprintf(s, true, buf, ret, reg);
+	}
+
+	for (i = 0; i < links; i++) {
+		ret += scnprintf(buf + ret, RD_BUF - ret, "\nLink%d\n", i);
+		ret += intel_sprintf(s, false, buf, ret, SDW_SHIM_CTLSCAP(i));
+		ret += intel_sprintf(s, false, buf, ret, SDW_SHIM_CTLS0CM(i));
+		ret += intel_sprintf(s, false, buf, ret, SDW_SHIM_CTLS1CM(i));
+		ret += intel_sprintf(s, false, buf, ret, SDW_SHIM_CTLS2CM(i));
+		ret += intel_sprintf(s, false, buf, ret, SDW_SHIM_CTLS3CM(i));
+		ret += intel_sprintf(s, false, buf, ret, SDW_SHIM_PCMSCAP(i));
+
+		ret += scnprintf(buf + ret, RD_BUF - ret, "\n PCMSyCH registers\n");
+
+		/*
+		 * the value 10 is the number of PDIs. We will need a
+		 * cleanup to remove hard-coded Intel configurations
+		 * from cadence_master.c
+		 */
+		for (j = 0; j < 10; j++) {
+			ret += intel_sprintf(s, false, buf, ret,
+					SDW_SHIM_PCMSYCHM(i, j));
+			ret += intel_sprintf(s, false, buf, ret,
+					SDW_SHIM_PCMSYCHC(i, j));
+		}
+		ret += scnprintf(buf + ret, RD_BUF - ret, "\n PDMSCAP, IOCTL, CTMCTL\n");
+
+		ret += intel_sprintf(s, false, buf, ret, SDW_SHIM_PDMSCAP(i));
+		ret += intel_sprintf(s, false, buf, ret, SDW_SHIM_IOCTL(i));
+		ret += intel_sprintf(s, false, buf, ret, SDW_SHIM_CTMCTL(i));
+	}
+
+	ret += scnprintf(buf + ret, RD_BUF - ret, "\nWake registers\n");
+	ret += intel_sprintf(s, false, buf, ret, SDW_SHIM_WAKEEN);
+	ret += intel_sprintf(s, false, buf, ret, SDW_SHIM_WAKESTS);
+
+	ret += scnprintf(buf + ret, RD_BUF - ret, "\nALH STRMzCFG\n");
+	for (i = 0; i < SDW_ALH_NUM_STREAMS; i++)
+		ret += intel_sprintf(a, true, buf, ret, SDW_ALH_STRMZCFG(i));
+
+	seq_printf(s_file, "%s", buf);
+	kfree(buf);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(intel_reg);
+
+static void intel_debugfs_init(struct sdw_intel *sdw)
+{
+	struct dentry *root = sdw->cdns.bus.debugfs;
+
+	if (!root)
+		return;
+
+	sdw->fs = debugfs_create_dir("intel-sdw", root);
+
+	debugfs_create_file("intel-registers", 0400, sdw->fs, sdw,
+			    &intel_reg_fops);
+
+	sdw_cdns_debugfs_init(&sdw->cdns, sdw->fs);
+}
+
+static void intel_debugfs_exit(struct sdw_intel *sdw)
+{
+	debugfs_remove_recursive(sdw->fs);
+}
+
 /*
  * shim ops
  */
@@ -885,6 +996,8 @@ static int intel_probe(struct platform_device *pdev)
 		goto err_dai;
 	}
 
+	intel_debugfs_init(sdw);
+
 	return 0;
 
 err_dai:
@@ -901,6 +1014,7 @@ static int intel_remove(struct platform_device *pdev)
 
 	sdw = platform_get_drvdata(pdev);
 
+	intel_debugfs_exit(sdw);
 	free_irq(sdw->res->irq, sdw);
 	snd_soc_unregister_component(sdw->cdns.dev);
 	sdw_delete_bus_master(&sdw->cdns.bus);
-- 
2.20.1

Re: [PATCH 1/3] soundwire: add debugfs support

[Greg KH]

On Fri, Aug 09, 2019 at 05:43:39PM -0500, Pierre-Louis Bossart wrote:
> Add base debugfs mechanism for SoundWire bus by creating soundwire
> root and master-N and slave-x hierarchy.
> 
> Also add SDW Slave SCP, DP0 and DP-N register debug file.
> 
> Registers not implemented will print as "XX"
> 
> Credits: this patch is based on an earlier internal contribution by
> Vinod Koul, Sanyog Kale, Shreyas Nc and Hardik Shah.
> 
> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
> ---
>  drivers/soundwire/Makefile    |   5 ++
>  drivers/soundwire/bus.c       |   6 ++
>  drivers/soundwire/bus.h       |  24 ++++++
>  drivers/soundwire/bus_type.c  |   3 +
>  drivers/soundwire/debugfs.c   | 151 ++++++++++++++++++++++++++++++++++
>  drivers/soundwire/slave.c     |   1 +
>  include/linux/soundwire/sdw.h |   4 +
>  7 files changed, 194 insertions(+)
>  create mode 100644 drivers/soundwire/debugfs.c
> 
> diff --git a/drivers/soundwire/Makefile b/drivers/soundwire/Makefile
> index fd99a831b92a..05d4cb9ef7d6 100644
> --- a/drivers/soundwire/Makefile
> +++ b/drivers/soundwire/Makefile
> @@ -5,6 +5,11 @@
>  
>  #Bus Objs
>  soundwire-bus-objs := bus_type.o bus.o slave.o mipi_disco.o stream.o
> +
> +ifdef CONFIG_DEBUG_FS
> +soundwire-bus-objs += debugfs.o
> +endif
> +
>  obj-$(CONFIG_SOUNDWIRE_BUS) += soundwire-bus.o
>  
>  #Cadence Objs
> diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
> index 49f64b2115b9..89d5f1537d9b 100644
> --- a/drivers/soundwire/bus.c
> +++ b/drivers/soundwire/bus.c
> @@ -49,6 +49,8 @@ int sdw_add_bus_master(struct sdw_bus *bus)
>  		}
>  	}
>  
> +	bus->debugfs = sdw_bus_debugfs_init(bus);
> +

It's "nicer" to just put that assignment into sdw_bus_debugfs_init().

That way you just call the function, no need to return anything.

>  	/*
>  	 * Device numbers in SoundWire are 0 through 15. Enumeration device
>  	 * number (0), Broadcast device number (15), Group numbers (12 and
> @@ -109,6 +111,8 @@ static int sdw_delete_slave(struct device *dev, void *data)
>  	struct sdw_slave *slave = dev_to_sdw_dev(dev);
>  	struct sdw_bus *bus = slave->bus;
>  
> +	sdw_slave_debugfs_exit(slave->debugfs);

Same here, just pass in slave:
	sdw_slave_debugfs_exit(slave);
and have that function remove the debugfs entry in the structure.  That
way, if you are really paranoid about size, you could even drop the
debugfs structure member from non-debugfs builds without any changes to
bus.c or other non-debugfs files.

thanks,

greg k-h

Re: [PATCH 2/3] soundwire: cadence_master: add debugfs register dump

[Greg KH]

On Fri, Aug 09, 2019 at 05:43:40PM -0500, Pierre-Louis Bossart wrote:
> +/**
> + * sdw_cdns_debugfs_init() - Cadence debugfs init
> + * @cdns: Cadence instance
> + * @root: debugfs root
> + */
> +void sdw_cdns_debugfs_init(struct sdw_cdns *cdns, struct dentry *root)
> +{
> +	debugfs_create_file("cdns-registers", 0400, root, cdns, &cdns_reg_fops);
> +}
> +EXPORT_SYMBOL_GPL(sdw_cdns_debugfs_init);

You create this function but never actually call it.  Don't add apis
that no one uses :(

thanks,

greg k-h

Re: [PATCH 3/3] soundwire: intel: add debugfs register dump

[Greg KH]

On Fri, Aug 09, 2019 at 05:43:41PM -0500, Pierre-Louis Bossart wrote:
> @@ -885,6 +996,8 @@ static int intel_probe(struct platform_device *pdev)
>  		goto err_dai;
>  	}
>  
> +	intel_debugfs_init(sdw);

See, make patch 1/3 work the same like this.  It's much cleaner.

thanks,

greg k-h

Re: [alsa-devel] [PATCH 1/3] soundwire: add debugfs support

[Pierre-Louis Bossart]

>>   #Cadence Objs
>> diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
>> index 49f64b2115b9..89d5f1537d9b 100644
>> --- a/drivers/soundwire/bus.c
>> +++ b/drivers/soundwire/bus.c
>> @@ -49,6 +49,8 @@ int sdw_add_bus_master(struct sdw_bus *bus)
>>   		}
>>   	}
>>   
>> +	bus->debugfs = sdw_bus_debugfs_init(bus);
>> +
> 
> It's "nicer" to just put that assignment into sdw_bus_debugfs_init().
> 
> That way you just call the function, no need to return anything.

ok, thanks for the suggestion.

> 
>>   	/*
>>   	 * Device numbers in SoundWire are 0 through 15. Enumeration device
>>   	 * number (0), Broadcast device number (15), Group numbers (12 and
>> @@ -109,6 +111,8 @@ static int sdw_delete_slave(struct device *dev, void *data)
>>   	struct sdw_slave *slave = dev_to_sdw_dev(dev);
>>   	struct sdw_bus *bus = slave->bus;
>>   
>> +	sdw_slave_debugfs_exit(slave->debugfs);
> 
> Same here, just pass in slave:
> 	sdw_slave_debugfs_exit(slave);
> and have that function remove the debugfs entry in the structure.  That
> way, if you are really paranoid about size, you could even drop the
> debugfs structure member from non-debugfs builds without any changes to
> bus.c or other non-debugfs files.

ok makes sense. will fix in v2.

Re: [alsa-devel] [PATCH 2/3] soundwire: cadence_master: add debugfs register dump

[Pierre-Louis Bossart]

On 8/10/19 2:03 AM, Greg KH wrote:
> On Fri, Aug 09, 2019 at 05:43:40PM -0500, Pierre-Louis Bossart wrote:
>> +/**
>> + * sdw_cdns_debugfs_init() - Cadence debugfs init
>> + * @cdns: Cadence instance
>> + * @root: debugfs root
>> + */
>> +void sdw_cdns_debugfs_init(struct sdw_cdns *cdns, struct dentry *root)
>> +{
>> +	debugfs_create_file("cdns-registers", 0400, root, cdns, &cdns_reg_fops);
>> +}
>> +EXPORT_SYMBOL_GPL(sdw_cdns_debugfs_init);
> 
> You create this function but never actually call it.  Don't add apis
> that no one uses :(

it is used in the follow-up patch.

+static void intel_debugfs_init(struct sdw_intel *sdw)
+{
+	struct dentry *root = sdw->cdns.bus.debugfs;
+
+	if (!root)
+		return;
+
+	sdw->fs = debugfs_create_dir("intel-sdw", root);
+
+	debugfs_create_file("intel-registers", 0400, sdw->fs, sdw,
+			    &intel_reg_fops);
+
+	sdw_cdns_debugfs_init(&sdw->cdns, sdw->fs); <<< HERE!
+}

The Cadence IP might be used by others so having a function that can be 
exported and used by others seems useful.