From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Vinod Koul <vinod.koul@intel.com>
Date: Mon, 31 Aug 2015 14:05:10 +0530
Subject: [PATCH] ASoC: Intel: Skylake: Add NHLT override control

For debugging purposes we may want to not use the BIOS values and
test our own values, so allow the override by adding a control
file for override method

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Guneshwor Singh <guneshwor.o.singh@intel.com>
---
 sound/soc/intel/skylake/skl-debug.c | 65 +++++++++++++++++++++++++++++
 sound/soc/intel/skylake/skl.h       |  1 +
 2 files changed, 66 insertions(+)

diff --git a/sound/soc/intel/skylake/skl-debug.c b/sound/soc/intel/skylake/skl-debug.c
index a0714c0e6e8b..d848f5fe0956 100644
--- a/sound/soc/intel/skylake/skl-debug.c
+++ b/sound/soc/intel/skylake/skl-debug.c
@@ -33,6 +33,7 @@ struct skl_debug {
 
 	struct dentry *fs;
 	struct dentry *modules;
+	struct dentry *nhlt;
 	u8 fw_read_buff[FW_REG_BUF];
 };
 
@@ -223,6 +224,61 @@ static const struct file_operations soft_regs_ctrl_fops = {
 	.llseek = default_llseek,
 };
 
+static ssize_t nhlt_control_read(struct file *file,
+			char __user *user_buf, size_t count, loff_t *ppos)
+{
+	struct skl_debug *d = file->private_data;
+	char *state;
+
+	state = d->skl->nhlt_override ? "enable\n" : "disable\n";
+	return simple_read_from_buffer(user_buf, count, ppos,
+			state, strlen(state));
+}
+
+static ssize_t nhlt_control_write(struct file *file,
+		const char __user *user_buf, size_t count, loff_t *ppos)
+{
+	struct skl_debug *d = file->private_data;
+	char buf[16];
+	int len = min(count, (sizeof(buf) - 1));
+
+
+	if (copy_from_user(buf, user_buf, len))
+		return -EFAULT;
+	buf[len] = 0;
+
+	if (!strncmp(buf, "enable\n", len))
+		d->skl->nhlt_override = true;
+	else if (!strncmp(buf, "disable\n", len))
+		d->skl->nhlt_override = false;
+	else
+		return -EINVAL;
+
+	/* Userspace has been fiddling around behind the kernel's back */
+	add_taint(TAINT_USER, LOCKDEP_NOW_UNRELIABLE);
+
+	return len;
+}
+
+static const struct file_operations ssp_cntrl_nhlt_fops = {
+	.open = simple_open,
+	.read = nhlt_control_read,
+	.write = nhlt_control_write,
+	.llseek = default_llseek,
+};
+
+static int skl_init_nhlt(struct skl_debug *d)
+{
+	if (!debugfs_create_file("control",
+				0644, d->nhlt,
+				d, &ssp_cntrl_nhlt_fops)) {
+		dev_err(d->dev, "nhlt control debugfs init failed\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
 struct skl_debug *skl_debugfs_init(struct skl *skl)
 {
 	struct skl_debug *d;
@@ -255,6 +311,15 @@ struct skl_debug *skl_debugfs_init(struct skl *skl)
 		goto err;
 	}
 
+	/* now create the NHLT dir */
+	d->nhlt =  debugfs_create_dir("nhlt", d->fs);
+	if (IS_ERR(d->nhlt) || !d->nhlt) {
+		dev_err(&skl->pci->dev, "nhlt debugfs create failed\n");
+		return NULL;
+	}
+
+	skl_init_nhlt(d);
+
 	return d;
 
 err:
diff --git a/sound/soc/intel/skylake/skl.h b/sound/soc/intel/skylake/skl.h
index 78aa8bdcb619..28c62dda07db 100644
--- a/sound/soc/intel/skylake/skl.h
+++ b/sound/soc/intel/skylake/skl.h
@@ -103,6 +103,7 @@ struct skl {
 	bool use_tplg_pcm;
 	struct skl_fw_config cfg;
 	struct snd_soc_acpi_mach *mach;
+	bool nhlt_override;
 };
 
 #define skl_to_bus(s)  (&(s)->hbus)
-- 
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