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Date: Fri, 14 Jan 2022 11:39:47 -0500
From: Sean Anderson <sean.anderson@...o.com>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
linux-usb@...r.kernel.org
Cc: Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
linux-kernel@...r.kernel.org,
Sean Anderson <sean.anderson@...o.com>
Subject: [PATCH] usb: ulpi: Add debugfs support
This adds a debugfs file for ULPI devices which contains a dump of their
registers. This is useful for debugging basic connectivity problems. The
file is created in ulpi_register because many devices will never have a
driver bound (as they are managed in hardware by the USB controller
device).
Signed-off-by: Sean Anderson <sean.anderson@...o.com>
---
drivers/usb/common/ulpi.c | 100 ++++++++++++++++++++++++++++++++++--
include/linux/ulpi/driver.h | 3 ++
2 files changed, 99 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
index 4169cf40a03b..a39c48e04013 100644
--- a/drivers/usb/common/ulpi.c
+++ b/drivers/usb/common/ulpi.c
@@ -13,6 +13,7 @@
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/acpi.h>
+#include <linux/debugfs.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/clk/clk-conf.h>
@@ -228,9 +229,64 @@ static int ulpi_read_id(struct ulpi *ulpi)
return 0;
}
+static int __maybe_unused ulpi_regs_read(struct seq_file *seq, void *data)
+{
+ struct ulpi *ulpi = seq->private;
+
+#define ulpi_print(name, reg) do { \
+ int ret = ulpi_read(ulpi, reg); \
+ if (ret < 0) \
+ return ret; \
+ seq_printf(seq, name " %.02x\n", ret); \
+} while (0)
+
+ ulpi_print("Vendor ID Low ", ULPI_VENDOR_ID_LOW);
+ ulpi_print("Vendor ID High ", ULPI_VENDOR_ID_HIGH);
+ ulpi_print("Product ID Low ", ULPI_PRODUCT_ID_LOW);
+ ulpi_print("Product ID High ", ULPI_PRODUCT_ID_HIGH);
+ ulpi_print("Function Control ", ULPI_FUNC_CTRL);
+ ulpi_print("Interface Control ", ULPI_IFC_CTRL);
+ ulpi_print("OTG Control ", ULPI_OTG_CTRL);
+ ulpi_print("USB Interrupt Enable Rising ", ULPI_USB_INT_EN_RISE);
+ ulpi_print("USB Interrupt Enable Falling", ULPI_USB_INT_EN_FALL);
+ ulpi_print("USB Interrupt Status ", ULPI_USB_INT_STS);
+ ulpi_print("USB Interrupt Latch ", ULPI_USB_INT_LATCH);
+ ulpi_print("Debug ", ULPI_DEBUG);
+ ulpi_print("Scratch Register ", ULPI_SCRATCH);
+ ulpi_print("Carkit Control ", ULPI_CARKIT_CTRL);
+ ulpi_print("Carkit Interrupt Delay ", ULPI_CARKIT_INT_DELAY);
+ ulpi_print("Carkit Interrupt Enable ", ULPI_CARKIT_INT_EN);
+ ulpi_print("Carkit Interrupt Status ", ULPI_CARKIT_INT_STS);
+ ulpi_print("Carkit Interrupt Latch ", ULPI_CARKIT_INT_LATCH);
+ ulpi_print("Carkit Pulse Control ", ULPI_CARKIT_PLS_CTRL);
+ ulpi_print("Transmit Positive Width ", ULPI_TX_POS_WIDTH);
+ ulpi_print("Transmit Negative Width ", ULPI_TX_NEG_WIDTH);
+ ulpi_print("Receive Polarity Recovery ", ULPI_POLARITY_RECOVERY);
+
+ return 0;
+}
+
+static int __maybe_unused ulpi_regs_open(struct inode *inode, struct file *f)
+{
+ struct ulpi *ulpi = inode->i_private;
+
+ return single_open(f, ulpi_regs_read, ulpi);
+}
+
+static const struct file_operations __maybe_unused ulpi_regs_ops = {
+ .owner = THIS_MODULE,
+ .open = ulpi_regs_open,
+ .release = single_release,
+ .read = seq_read,
+ .llseek = seq_lseek
+};
+
+static struct dentry *ulpi_root = (void *)-EPROBE_DEFER;
+
static int ulpi_register(struct device *dev, struct ulpi *ulpi)
{
int ret;
+ struct dentry *regs;
ulpi->dev.parent = dev; /* needed early for ops */
ulpi->dev.bus = &ulpi_bus;
@@ -245,16 +301,39 @@ static int ulpi_register(struct device *dev, struct ulpi *ulpi)
ret = ulpi_read_id(ulpi);
if (ret)
- return ret;
+ goto err_of;
ret = device_register(&ulpi->dev);
if (ret)
- return ret;
+ goto err_of;
+
+ if (IS_ENABLED(CONFIG_DEBUG_FS)) {
+ ulpi->root = debugfs_create_dir(dev_name(dev), ulpi_root);
+ if (IS_ERR(ulpi->root)) {
+ ret = PTR_ERR(ulpi->root);
+ goto err_dev;
+ }
+
+ regs = debugfs_create_file("regs", 0444, ulpi->root, ulpi,
+ &ulpi_regs_ops);
+ if (IS_ERR(regs)) {
+ ret = PTR_ERR(regs);
+ goto err_debugfs;
+ }
+ }
dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n",
ulpi->id.vendor, ulpi->id.product);
return 0;
+
+err_debugfs:
+ debugfs_remove(ulpi->root);
+err_dev:
+ device_unregister(&ulpi->dev);
+err_of:
+ of_node_put(ulpi->dev.of_node);
+ return ret;
}
/**
@@ -296,8 +375,9 @@ EXPORT_SYMBOL_GPL(ulpi_register_interface);
*/
void ulpi_unregister_interface(struct ulpi *ulpi)
{
- of_node_put(ulpi->dev.of_node);
+ debugfs_remove_recursive(ulpi->root);
device_unregister(&ulpi->dev);
+ of_node_put(ulpi->dev.of_node);
}
EXPORT_SYMBOL_GPL(ulpi_unregister_interface);
@@ -305,13 +385,25 @@ EXPORT_SYMBOL_GPL(ulpi_unregister_interface);
static int __init ulpi_init(void)
{
- return bus_register(&ulpi_bus);
+ int ret;
+
+ if (IS_ENABLED(CONFIG_DEBUG_FS)) {
+ ulpi_root = debugfs_create_dir("ulpi", NULL);
+ if (IS_ERR(ulpi_root))
+ return PTR_ERR(ulpi_root);
+ }
+
+ ret = bus_register(&ulpi_bus);
+ if (ret)
+ debugfs_remove(ulpi_root);
+ return ret;
}
subsys_initcall(ulpi_init);
static void __exit ulpi_exit(void)
{
bus_unregister(&ulpi_bus);
+ debugfs_remove(ulpi_root);
}
module_exit(ulpi_exit);
diff --git a/include/linux/ulpi/driver.h b/include/linux/ulpi/driver.h
index c7a1810373e3..083ea2d2e873 100644
--- a/include/linux/ulpi/driver.h
+++ b/include/linux/ulpi/driver.h
@@ -6,6 +6,7 @@
#include <linux/device.h>
+struct dentry;
struct ulpi_ops;
/**
@@ -13,10 +14,12 @@ struct ulpi_ops;
* @id: vendor and product ids for ULPI device
* @ops: I/O access
* @dev: device interface
+ * @root: root directory for debugfs files
*/
struct ulpi {
struct ulpi_device_id id;
const struct ulpi_ops *ops;
+ struct dentry *root;
struct device dev;
};
--
2.25.1
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