1 files changed, 205 insertions, 5 deletions

diff --git a/drivers/soundwire/debugfs.c b/drivers/soundwire/debugfs.c
index 67abd7e52f09..3099ea074f10 100644
--- a/drivers/soundwire/debugfs.c
+++ b/drivers/soundwire/debugfs.c
@@ -1,13 +1,16 @@
 // SPDX-License-Identifier: GPL-2.0-only
 // Copyright(c) 2017-2019 Intel Corporation.
 
+#include <linux/cleanup.h>
 #include <linux/device.h>
 #include <linux/debugfs.h>
+#include <linux/firmware.h>
 #include <linux/mod_devicetable.h>
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
 #include <linux/soundwire/sdw.h>
 #include <linux/soundwire/sdw_registers.h>
+#include <linux/string_choices.h>
 #include "bus.h"
 
 static struct dentry *sdw_debugfs_root;
@@ -48,18 +51,16 @@ static ssize_t sdw_sprintf(struct sdw_slave *slave,
 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);
+	char *buf __free(kfree) = kzalloc(RD_BUF, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 
 	ret = pm_runtime_get_sync(&slave->dev);
 	if (ret < 0 && ret != -EACCES) {
 		pm_runtime_put_noidle(&slave->dev);
-		kfree(buf);
 		return ret;
 	}
 
@@ -131,12 +132,200 @@ static int sdw_slave_reg_show(struct seq_file *s_file, void *data)
 	pm_runtime_mark_last_busy(&slave->dev);
 	pm_runtime_put(&slave->dev);
 
-	kfree(buf);
-
 	return 0;
 }
 DEFINE_SHOW_ATTRIBUTE(sdw_slave_reg);
 
+#define MAX_CMD_BYTES (1024 * 1024)
+
+static int cmd;
+static int cmd_type;
+static u32 start_addr;
+static size_t num_bytes;
+static u8 read_buffer[MAX_CMD_BYTES];
+static char *firmware_file;
+
+static int set_command(void *data, u64 value)
+{
+	struct sdw_slave *slave = data;
+
+	if (value > 1)
+		return -EINVAL;
+
+	/* Userspace changed the hardware state behind the kernel's back */
+	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+
+	dev_dbg(&slave->dev, "command: %s\n", str_read_write(value));
+	cmd = value;
+
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(set_command_fops, NULL,
+			 set_command, "%llu\n");
+
+static int set_command_type(void *data, u64 value)
+{
+	struct sdw_slave *slave = data;
+
+	if (value > 1)
+		return -EINVAL;
+
+	/* Userspace changed the hardware state behind the kernel's back */
+	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+
+	dev_dbg(&slave->dev, "command type: %s\n", value ? "BRA" : "Column0");
+
+	cmd_type = (int)value;
+
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(set_command_type_fops, NULL,
+			 set_command_type, "%llu\n");
+
+static int set_start_address(void *data, u64 value)
+{
+	struct sdw_slave *slave = data;
+
+	/* Userspace changed the hardware state behind the kernel's back */
+	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+
+	dev_dbg(&slave->dev, "start address %#llx\n", value);
+
+	start_addr = value;
+
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(set_start_address_fops, NULL,
+			 set_start_address, "%llu\n");
+
+static int set_num_bytes(void *data, u64 value)
+{
+	struct sdw_slave *slave = data;
+
+	if (value == 0 || value > MAX_CMD_BYTES)
+		return -EINVAL;
+
+	/* Userspace changed the hardware state behind the kernel's back */
+	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+
+	dev_dbg(&slave->dev, "number of bytes %lld\n", value);
+
+	num_bytes = value;
+
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(set_num_bytes_fops, NULL,
+			 set_num_bytes, "%llu\n");
+
+static int do_bpt_sequence(struct sdw_slave *slave, bool write, u8 *buffer)
+{
+	struct sdw_bpt_msg msg = {0};
+
+	msg.addr = start_addr;
+	msg.len = num_bytes;
+	msg.dev_num = slave->dev_num;
+	if (write)
+		msg.flags = SDW_MSG_FLAG_WRITE;
+	else
+		msg.flags = SDW_MSG_FLAG_READ;
+	msg.buf = buffer;
+
+	return sdw_bpt_send_sync(slave->bus, slave, &msg);
+}
+
+static int cmd_go(void *data, u64 value)
+{
+	const struct firmware *fw = NULL;
+	struct sdw_slave *slave = data;
+	ktime_t start_t;
+	ktime_t finish_t;
+	int ret;
+
+	if (value != 1)
+		return -EINVAL;
+
+	/* one last check */
+	if (start_addr > SDW_REG_MAX ||
+	    num_bytes == 0 || num_bytes > MAX_CMD_BYTES)
+		return -EINVAL;
+
+	ret = pm_runtime_get_sync(&slave->dev);
+	if (ret < 0 && ret != -EACCES) {
+		pm_runtime_put_noidle(&slave->dev);
+		return ret;
+	}
+
+	if (cmd == 0) {
+		ret = request_firmware(&fw, firmware_file, &slave->dev);
+		if (ret < 0) {
+			dev_err(&slave->dev, "firmware %s not found\n", firmware_file);
+			goto out;
+		}
+		if (fw->size < num_bytes) {
+			dev_err(&slave->dev,
+				"firmware %s: firmware size %zd, desired %zd\n",
+				firmware_file, fw->size, num_bytes);
+			goto out;
+		}
+	}
+
+	/* Userspace changed the hardware state behind the kernel's back */
+	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+
+	dev_dbg(&slave->dev, "starting command\n");
+	start_t = ktime_get();
+
+	if (cmd == 0) {
+		if (cmd_type)
+			ret = do_bpt_sequence(slave, true, (u8 *)fw->data);
+		else
+			ret = sdw_nwrite_no_pm(slave, start_addr, num_bytes, fw->data);
+	} else {
+		memset(read_buffer, 0, sizeof(read_buffer));
+
+		if (cmd_type)
+			ret = do_bpt_sequence(slave, false, read_buffer);
+		else
+			ret = sdw_nread_no_pm(slave, start_addr, num_bytes, read_buffer);
+	}
+
+	finish_t = ktime_get();
+
+out:
+	if (fw)
+		release_firmware(fw);
+
+	pm_runtime_mark_last_busy(&slave->dev);
+	pm_runtime_put(&slave->dev);
+
+	dev_dbg(&slave->dev, "command completed, num_byte %zu status %d, time %lld ms\n",
+		num_bytes, ret, div_u64(finish_t - start_t, NSEC_PER_MSEC));
+
+	return ret;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(cmd_go_fops, NULL,
+			 cmd_go, "%llu\n");
+
+#define MAX_LINE_LEN 128
+
+static int read_buffer_show(struct seq_file *s_file, void *data)
+{
+	char buf[MAX_LINE_LEN];
+	int i;
+
+	if (num_bytes == 0 || num_bytes > MAX_CMD_BYTES)
+		return -EINVAL;
+
+	for (i = 0; i < num_bytes; i++) {
+		scnprintf(buf, MAX_LINE_LEN, "address %#x val 0x%02x\n",
+			  start_addr + i, read_buffer[i]);
+		seq_printf(s_file, "%s", buf);
+	}
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(read_buffer);
+
 void sdw_slave_debugfs_init(struct sdw_slave *slave)
 {
 	struct dentry *master;
@@ -151,6 +340,17 @@ void sdw_slave_debugfs_init(struct sdw_slave *slave)
 
 	debugfs_create_file("registers", 0400, d, slave, &sdw_slave_reg_fops);
 
+	/* interface to send arbitrary commands */
+	debugfs_create_file("command", 0200, d, slave, &set_command_fops);
+	debugfs_create_file("command_type", 0200, d, slave, &set_command_type_fops);
+	debugfs_create_file("start_address", 0200, d, slave, &set_start_address_fops);
+	debugfs_create_file("num_bytes", 0200, d, slave, &set_num_bytes_fops);
+	debugfs_create_file("go", 0200, d, slave, &cmd_go_fops);
+
+	debugfs_create_file("read_buffer", 0400, d, slave, &read_buffer_fops);
+	firmware_file = NULL;
+	debugfs_create_str("firmware_file", 0200, d, &firmware_file);
+
 	slave->debugfs = d;
 }