soundwire: intel_ace2x: add debugfs support

Add access to registers in SHIM and SHIM_VS (vendor-specific) areas.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20230515071042.2038-11-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/soundwire/Makefile

@@ -24,7 +24,8 @@ soundwire-cadence-y := cadence_master.o
 obj-$(CONFIG_SOUNDWIRE_CADENCE) += soundwire-cadence.o
 
 #Intel driver
-soundwire-intel-y :=	intel.o  intel_ace2x.o intel_auxdevice.o intel_init.o dmi-quirks.o \
+soundwire-intel-y :=	intel.o intel_ace2x.o intel_ace2x_debugfs.o \
+			intel_auxdevice.o intel_init.o dmi-quirks.o \
 			intel_bus_common.o
 obj-$(CONFIG_SOUNDWIRE_INTEL) += soundwire-intel.o
 

drivers/soundwire/intel.h

@@ -95,6 +95,14 @@ static inline void intel_writew(void __iomem *base, int offset, u16 value)
 					 (sdw)->link_res->hw_ops->cb)
 #define SDW_INTEL_OPS(sdw, cb)		((sdw)->link_res->hw_ops->cb)
 
+#ifdef CONFIG_DEBUG_FS
+void intel_ace2x_debugfs_init(struct sdw_intel *sdw);
+void intel_ace2x_debugfs_exit(struct sdw_intel *sdw);
+#else
+static inline void intel_ace2x_debugfs_init(struct sdw_intel *sdw) {}
+static inline void intel_ace2x_debugfs_exit(struct sdw_intel *sdw) {}
+#endif
+
 static inline void sdw_intel_debugfs_init(struct sdw_intel *sdw)
 {
 	if (SDW_INTEL_CHECK_OPS(sdw, debugfs_init))

drivers/soundwire/intel_ace2x.c

@@ -15,5 +15,7 @@
 #include "intel.h"
 
 const struct sdw_intel_hw_ops sdw_intel_lnl_hw_ops = {
+	.debugfs_init = intel_ace2x_debugfs_init,
+	.debugfs_exit = intel_ace2x_debugfs_exit,
 };
 EXPORT_SYMBOL_NS(sdw_intel_lnl_hw_ops, SOUNDWIRE_INTEL);

drivers/soundwire/intel_ace2x_debugfs.c

@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright(c) 2023 Intel Corporation. All rights reserved.
+
+#include <linux/acpi.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/pm_runtime.h>
+#include <linux/soundwire/sdw.h>
+#include <linux/soundwire/sdw_intel.h>
+#include <linux/soundwire/sdw_registers.h>
+#include "bus.h"
+#include "cadence_master.h"
+#include "intel.h"
+
+/*
+ * debugfs
+ */
+#ifdef CONFIG_DEBUG_FS
+
+#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->link_res->shim;
+	void __iomem *vs_s = sdw->link_res->shim_vs;
+	ssize_t ret;
+	u32 pcm_cap;
+	int pcm_bd;
+	char *buf;
+	int 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, "\nShim\n");
+
+	ret += intel_sprintf(s, true, buf, ret, SDW_SHIM2_LECAP);
+	ret += intel_sprintf(s, false, buf, ret, SDW_SHIM2_PCMSCAP);
+
+	pcm_cap = intel_readw(s, SDW_SHIM2_PCMSCAP);
+	pcm_bd = FIELD_GET(SDW_SHIM2_PCMSCAP_BSS, pcm_cap);
+
+	for (j = 0; j < pcm_bd; j++) {
+		ret += intel_sprintf(s, false, buf, ret,
+				SDW_SHIM2_PCMSYCHM(j));
+		ret += intel_sprintf(s, false, buf, ret,
+				SDW_SHIM2_PCMSYCHC(j));
+	}
+
+	ret += scnprintf(buf + ret, RD_BUF - ret, "\nVS CLK controls\n");
+	ret += intel_sprintf(vs_s, true, buf, ret, SDW_SHIM2_INTEL_VS_LVSCTL);
+
+	ret += scnprintf(buf + ret, RD_BUF - ret, "\nVS Wake registers\n");
+	ret += intel_sprintf(vs_s, false, buf, ret, SDW_SHIM2_INTEL_VS_WAKEEN);
+	ret += intel_sprintf(vs_s, false, buf, ret, SDW_SHIM2_INTEL_VS_WAKESTS);
+
+	ret += scnprintf(buf + ret, RD_BUF - ret, "\nVS IOCTL, ACTMCTL\n");
+	ret += intel_sprintf(vs_s, false, buf, ret, SDW_SHIM2_INTEL_VS_IOCTL);
+	ret += intel_sprintf(vs_s, false, buf, ret, SDW_SHIM2_INTEL_VS_ACTMCTL);
+
+	seq_printf(s_file, "%s", buf);
+	kfree(buf);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(intel_reg);
+
+static int intel_set_m_datamode(void *data, u64 value)
+{
+	struct sdw_intel *sdw = data;
+	struct sdw_bus *bus = &sdw->cdns.bus;
+
+	if (value > SDW_PORT_DATA_MODE_STATIC_1)
+		return -EINVAL;
+
+	/* Userspace changed the hardware state behind the kernel's back */
+	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+
+	bus->params.m_data_mode = value;
+
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(intel_set_m_datamode_fops, NULL,
+			 intel_set_m_datamode, "%llu\n");
+
+static int intel_set_s_datamode(void *data, u64 value)
+{
+	struct sdw_intel *sdw = data;
+	struct sdw_bus *bus = &sdw->cdns.bus;
+
+	if (value > SDW_PORT_DATA_MODE_STATIC_1)
+		return -EINVAL;
+
+	/* Userspace changed the hardware state behind the kernel's back */
+	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+
+	bus->params.s_data_mode = value;
+
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(intel_set_s_datamode_fops, NULL,
+			 intel_set_s_datamode, "%llu\n");
+
+void intel_ace2x_debugfs_init(struct sdw_intel *sdw)
+{
+	struct dentry *root = sdw->cdns.bus.debugfs;
+
+	if (!root)
+		return;
+
+	sdw->debugfs = debugfs_create_dir("intel-sdw", root);
+
+	debugfs_create_file("intel-registers", 0400, sdw->debugfs, sdw,
+			    &intel_reg_fops);
+
+	debugfs_create_file("intel-m-datamode", 0200, sdw->debugfs, sdw,
+			    &intel_set_m_datamode_fops);
+
+	debugfs_create_file("intel-s-datamode", 0200, sdw->debugfs, sdw,
+			    &intel_set_s_datamode_fops);
+
+	sdw_cdns_debugfs_init(&sdw->cdns, sdw->debugfs);
+}
+
+void intel_ace2x_debugfs_exit(struct sdw_intel *sdw)
+{
+	debugfs_remove_recursive(sdw->debugfs);
+}
+#endif /* CONFIG_DEBUG_FS */