ASoC: wcd938x: Add debug support for WCD938x soundwire slave

Add debug support for WCD938x soundwire slave register access. Change-Id: I5984a04cf144e7e858addc5cd060e0ec1264f2a6 Signed-off-by: Sudheer Papothi <spapothi@codeaurora.org>
2019-08-29 15:00:22 +05:30
--- a/asoc/codecs/wcd938x/wcd938x-slave.c
+++ b/asoc/codecs/wcd938x/wcd938x-slave.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2018-2019, The Linux Foundation. All rights reserved.
 */

 #include <linux/module.h>
@@ -11,10 +11,267 @@
 #include <linux/component.h>
 #include <soc/soundwire.h>

+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+
+#define SWR_SLV_MAX_REG_ADDR    0x2009
+#define SWR_SLV_START_REG_ADDR  0x40
+#define SWR_SLV_MAX_BUF_LEN     20
+#define BYTES_PER_LINE          12
+#define SWR_SLV_RD_BUF_LEN      8
+#define SWR_SLV_WR_BUF_LEN      32
+#define SWR_SLV_MAX_DEVICES     2
+#endif /* CONFIG_DEBUG_FS */
+
 struct wcd938x_slave_priv {
 	struct swr_device *swr_slave;
+#ifdef CONFIG_DEBUG_FS
+	struct dentry *debugfs_wcd938x_dent;
+	struct dentry *debugfs_peek;
+	struct dentry *debugfs_poke;
+	struct dentry *debugfs_reg_dump;
+	unsigned int read_data;
+#endif
 };

+#ifdef CONFIG_DEBUG_FS
+static int codec_debug_open(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+	return 0;
+}
+
+static int get_parameters(char *buf, u32 *param1, int num_of_par)
+{
+	char *token = NULL;
+	int base = 0, cnt = 0;
+
+	token = strsep(&buf, " ");
+	for (cnt = 0; cnt < num_of_par; cnt++) {
+		if (token) {
+			if ((token[1] == 'x') || (token[1] == 'X'))
+				base = 16;
+			else
+				base = 10;
+
+			if (kstrtou32(token, base, &param1[cnt]) != 0)
+				return -EINVAL;
+
+			token = strsep(&buf, " ");
+		} else {
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+static bool is_swr_slv_reg_readable(int reg)
+{
+	int ret = true;
+
+	if (((reg > 0x46) && (reg < 0x4A)) ||
+	    ((reg > 0x4A) && (reg < 0x50)) ||
+	    ((reg > 0x55) && (reg < 0xD0)) ||
+	    ((reg > 0xD0) && (reg < 0xE0)) ||
+	    ((reg > 0xE0) && (reg < 0xF0)) ||
+	    ((reg > 0xF0) && (reg < 0x100)) ||
+	    ((reg > 0x105) && (reg < 0x120)) ||
+	    ((reg > 0x205) && (reg < 0x220)) ||
+	    ((reg > 0x305) && (reg < 0x320)) ||
+	    ((reg > 0x405) && (reg < 0x420)) ||
+	    ((reg > 0x128) && (reg < 0x130)) ||
+	    ((reg > 0x228) && (reg < 0x230)) ||
+	    ((reg > 0x328) && (reg < 0x330)) ||
+	    ((reg > 0x428) && (reg < 0x430)) ||
+	    ((reg > 0x138) && (reg < 0x205)) ||
+	    ((reg > 0x238) && (reg < 0x305)) ||
+	    ((reg > 0x338) && (reg < 0x405)) ||
+	    ((reg > 0x405) && (reg < 0xF00)) ||
+	    ((reg > 0xF05) && (reg < 0xF20)) ||
+	    ((reg > 0xF25) && (reg < 0xF30)) ||
+	    ((reg > 0xF35) && (reg < 0x2000)))
+		ret = false;
+
+	return ret;
+}
+
+static ssize_t wcd938x_swrslave_reg_show(struct swr_device *pdev,
+					char __user *ubuf,
+					size_t count, loff_t *ppos)
+{
+	int i, reg_val, len;
+	ssize_t total = 0;
+	char tmp_buf[SWR_SLV_MAX_BUF_LEN];
+
+	if (!ubuf || !ppos)
+		return 0;
+
+	for (i = (((int) *ppos/BYTES_PER_LINE) + SWR_SLV_START_REG_ADDR);
+		i <= SWR_SLV_MAX_REG_ADDR; i++) {
+		if (!is_swr_slv_reg_readable(i))
+			continue;
+		swr_read(pdev, pdev->dev_num, i, &reg_val, 1);
+		len = snprintf(tmp_buf, 25, "0x%.3x: 0x%.2x\n", i,
+			       (reg_val & 0xFF));
+		if ((total + len) >= count - 1)
+			break;
+		if (copy_to_user((ubuf + total), tmp_buf, len)) {
+			pr_err("%s: fail to copy reg dump\n", __func__);
+			total = -EFAULT;
+			goto copy_err;
+		}
+		total += len;
+		*ppos += len;
+	}
+
+copy_err:
+	*ppos = SWR_SLV_MAX_REG_ADDR * BYTES_PER_LINE;
+	return total;
+}
+
+static ssize_t codec_debug_dump(struct file *file, char __user *ubuf,
+				size_t count, loff_t *ppos)
+{
+	struct swr_device *pdev;
+
+	if (!count || !file || !ppos || !ubuf)
+		return -EINVAL;
+
+	pdev = file->private_data;
+	if (!pdev)
+		return -EINVAL;
+
+	if (*ppos < 0)
+		return -EINVAL;
+
+	return wcd938x_swrslave_reg_show(pdev, ubuf, count, ppos);
+}
+
+static ssize_t codec_debug_read(struct file *file, char __user *ubuf,
+				size_t count, loff_t *ppos)
+{
+	char lbuf[SWR_SLV_RD_BUF_LEN];
+	struct swr_device *pdev = NULL;
+	struct wcd938x_slave_priv *wcd938x_slave = NULL;
+
+	if (!count || !file || !ppos || !ubuf)
+		return -EINVAL;
+
+	pdev = file->private_data;
+	if (!pdev)
+		return -EINVAL;
+
+	wcd938x_slave = swr_get_dev_data(pdev);
+	if (!wcd938x_slave)
+		return -EINVAL;
+
+	if (*ppos < 0)
+		return -EINVAL;
+
+	snprintf(lbuf, sizeof(lbuf), "0x%x\n",
+			(wcd938x_slave->read_data & 0xFF));
+
+	return simple_read_from_buffer(ubuf, count, ppos, lbuf,
+					       strnlen(lbuf, 7));
+}
+
+static ssize_t codec_debug_peek_write(struct file *file,
+	const char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+	char lbuf[SWR_SLV_WR_BUF_LEN];
+	int rc = 0;
+	u32 param[5];
+	struct swr_device *pdev = NULL;
+	struct wcd938x_slave_priv *wcd938x_slave = NULL;
+
+	if (!cnt || !file || !ppos || !ubuf)
+		return -EINVAL;
+
+	pdev = file->private_data;
+	if (!pdev)
+		return -EINVAL;
+
+	wcd938x_slave = swr_get_dev_data(pdev);
+	if (!wcd938x_slave)
+		return -EINVAL;
+
+	if (*ppos < 0)
+		return -EINVAL;
+
+	if (cnt > sizeof(lbuf) - 1)
+		return -EINVAL;
+
+	rc = copy_from_user(lbuf, ubuf, cnt);
+	if (rc)
+		return -EFAULT;
+
+	lbuf[cnt] = '\0';
+	rc = get_parameters(lbuf, param, 1);
+	if (!((param[0] <= SWR_SLV_MAX_REG_ADDR) && (rc == 0)))
+		return -EINVAL;
+	swr_read(pdev, pdev->dev_num, param[0], &wcd938x_slave->read_data, 1);
+	if (rc == 0)
+		rc = cnt;
+	else
+		pr_err("%s: rc = %d\n", __func__, rc);
+
+	return rc;
+}
+
+static ssize_t codec_debug_write(struct file *file,
+	const char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+	char lbuf[SWR_SLV_WR_BUF_LEN];
+	int rc = 0;
+	u32 param[5];
+	struct swr_device *pdev;
+
+	if (!file || !ppos || !ubuf)
+		return -EINVAL;
+
+	pdev = file->private_data;
+	if (!pdev)
+		return -EINVAL;
+
+	if (cnt > sizeof(lbuf) - 1)
+		return -EINVAL;
+
+	rc = copy_from_user(lbuf, ubuf, cnt);
+	if (rc)
+		return -EFAULT;
+
+	lbuf[cnt] = '\0';
+	rc = get_parameters(lbuf, param, 2);
+	if (!((param[0] <= SWR_SLV_MAX_REG_ADDR) &&
+		(param[1] <= 0xFF) && (rc == 0)))
+		return -EINVAL;
+	swr_write(pdev, pdev->dev_num, param[0], &param[1]);
+	if (rc == 0)
+		rc = cnt;
+	else
+		pr_err("%s: rc = %d\n", __func__, rc);
+
+	return rc;
+}
+
+static const struct file_operations codec_debug_write_ops = {
+	.open = codec_debug_open,
+	.write = codec_debug_write,
+};
+
+static const struct file_operations codec_debug_read_ops = {
+	.open = codec_debug_open,
+	.read = codec_debug_read,
+	.write = codec_debug_peek_write,
+};
+
+static const struct file_operations codec_debug_dump_ops = {
+	.open = codec_debug_open,
+	.read = codec_debug_dump,
+};
+#endif
+
 static int wcd938x_slave_bind(struct device *dev,
 				struct device *master, void *data)
 {
@@ -82,11 +339,49 @@ static int wcd938x_swr_probe(struct swr_device *pdev)

 	wcd938x_slave->swr_slave = pdev;

+#ifdef CONFIG_DEBUG_FS
+	if (!wcd938x_slave->debugfs_wcd938x_dent) {
+		wcd938x_slave->debugfs_wcd938x_dent = debugfs_create_dir(
+						dev_name(&pdev->dev), 0);
+		if (!IS_ERR(wcd938x_slave->debugfs_wcd938x_dent)) {
+			wcd938x_slave->debugfs_peek =
+					debugfs_create_file("swrslave_peek",
+					S_IFREG | 0444,
+					wcd938x_slave->debugfs_wcd938x_dent,
+					(void *) pdev,
+					&codec_debug_read_ops);
+
+			wcd938x_slave->debugfs_poke =
+					debugfs_create_file("swrslave_poke",
+					S_IFREG | 0444,
+					wcd938x_slave->debugfs_wcd938x_dent,
+					(void *) pdev,
+					&codec_debug_write_ops);
+
+			wcd938x_slave->debugfs_reg_dump =
+					debugfs_create_file(
+					"swrslave_reg_dump",
+					S_IFREG | 0444,
+					wcd938x_slave->debugfs_wcd938x_dent,
+					(void *) pdev,
+					&codec_debug_dump_ops);
+                }
+        }
+#endif
+
 	return component_add(&pdev->dev, &wcd938x_slave_comp_ops);
 }

 static int wcd938x_swr_remove(struct swr_device *pdev)
 {
+#ifdef CONFIG_DEBUG_FS
+	struct wcd938x_slave_priv *wcd938x_slave = swr_get_dev_data(pdev);
+
+	if (wcd938x_slave) {
+		debugfs_remove_recursive(wcd938x_slave->debugfs_wcd938x_dent);
+		wcd938x_slave->debugfs_wcd938x_dent = NULL;
+	}
+#endif
 	component_del(&pdev->dev, &wcd938x_slave_comp_ops);
 	swr_set_dev_data(pdev, NULL);
 	swr_remove_device(pdev);