greybus: Dump log from APB1
On AP module (form factor), we don't have access to APBridge JTAG or UART.
But sometime, we still need to get log from APBridge. Add a new request in control endpoint
to get APBridge logs.
Logs can be accessed using debugfs (greybus/apb1_log).
Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/greybus/es1.c b/drivers/staging/greybus/es1.c
index bbf1bd1..9ad8a76 100644
--- a/drivers/staging/greybus/es1.c
+++ b/drivers/staging/greybus/es1.c
@@ -8,10 +8,14 @@
*/
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/kthread.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/sizes.h>
#include <linux/usb.h>
+#include <linux/kfifo.h>
+#include <linux/debugfs.h>
+#include <asm/uaccess.h>
#include "greybus.h"
#include "svc_msg.h"
@@ -35,6 +39,12 @@
};
MODULE_DEVICE_TABLE(usb, id_table);
+#define APB1_LOG_SIZE SZ_16K
+static struct dentry *apb1_log_dentry;
+static struct dentry *apb1_log_enable_dentry;
+static struct task_struct *apb1_log_task;
+static DEFINE_KFIFO(apb1_log_fifo, char, APB1_LOG_SIZE);
+
/*
* Number of CPort IN urbs in flight at any point in time.
* Adjust if we are having stalls in the USB buffer due to not enough urbs in
@@ -91,6 +101,7 @@
}
static void cport_out_callback(struct urb *urb);
+static void usb_log_enable(struct es1_ap_dev *es1, int enable);
/*
* Buffer constraints for the host driver.
@@ -326,6 +337,8 @@
if (!es1)
return;
+ usb_log_enable(es1, 0);
+
/* Tear down everything! */
for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
struct urb *urb = es1->cport_out_urb[i];
@@ -474,6 +487,125 @@
*/
}
+static void apb1_log_get(struct es1_ap_dev *es1)
+{
+ char buf[65];
+ int retval;
+
+ /* SVC messages go down our control pipe */
+ do {
+ memset(buf, 0, 65);
+ retval = usb_control_msg(es1->usb_dev,
+ usb_rcvctrlpipe(es1->usb_dev,
+ es1->control_endpoint),
+ 0x02, /* vendor request APB1 log */
+ USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+ 0x00, 0x00,
+ buf,
+ 64,
+ ES1_TIMEOUT);
+ if (retval > 0)
+ kfifo_in(&apb1_log_fifo, buf, retval);
+ } while (retval > 0);
+}
+
+static int apb1_log_poll(void *data)
+{
+ while (!kthread_should_stop()) {
+ msleep(1000);
+ apb1_log_get((struct es1_ap_dev *)data);
+ }
+ return 0;
+}
+
+static ssize_t apb1_log_read(struct file *f, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ ssize_t ret;
+ size_t copied;
+ char *tmp_buf;
+
+ if (count > APB1_LOG_SIZE)
+ count = APB1_LOG_SIZE;
+
+ tmp_buf = kmalloc(count, GFP_KERNEL);
+ if (!tmp_buf)
+ return -ENOMEM;
+
+ copied = kfifo_out(&apb1_log_fifo, tmp_buf, count);
+ ret = simple_read_from_buffer(buf, count, ppos, tmp_buf, copied);
+
+ kfree(tmp_buf);
+
+ return ret;
+}
+
+static struct file_operations apb1_log_fops = {
+ .read = apb1_log_read,
+};
+
+static void usb_log_enable(struct es1_ap_dev *es1, int enable)
+{
+ if (enable && apb1_log_task != NULL)
+ return;
+
+ if (enable) {
+ /* get log from APB1 */
+ apb1_log_task = kthread_run(apb1_log_poll, es1, "apb1_log");
+ if (apb1_log_task == ERR_PTR(-ENOMEM))
+ return;
+ apb1_log_dentry = debugfs_create_file("apb1_log", 444,
+ gb_debugfs_get(), NULL,
+ &apb1_log_fops);
+ } else {
+ if (apb1_log_dentry) {
+ debugfs_remove(apb1_log_dentry);
+ apb1_log_dentry = NULL;
+ }
+
+ if (apb1_log_task) {
+ kthread_stop(apb1_log_task);
+ apb1_log_task = NULL;
+ }
+ }
+}
+
+static ssize_t apb1_log_enable_read(struct file *f, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char tmp_buf[3];
+ int enable = apb1_log_task != NULL;
+ sprintf(tmp_buf, "%d\n", enable);
+ return simple_read_from_buffer(buf, count, ppos, tmp_buf, 3);
+}
+
+static ssize_t apb1_log_enable_write(struct file *f, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int enable;
+ char *tmp_buf;
+ ssize_t retval = -EINVAL;
+ struct es1_ap_dev *es1 = (struct es1_ap_dev *)f->f_inode->i_private;
+
+ tmp_buf = kmalloc(count, GFP_KERNEL);
+ if (!tmp_buf)
+ return -ENOMEM;
+
+ copy_from_user(tmp_buf, buf, count);
+ if (sscanf(tmp_buf, "%d", &enable) == 1) {
+ usb_log_enable(es1, enable);
+ retval = count;
+ }
+ kfree(tmp_buf);
+
+ return retval;
+}
+
+static struct file_operations apb1_log_enable_fops = {
+ .read = apb1_log_enable_read,
+ .write = apb1_log_enable_write,
+};
+
/*
* The ES1 USB Bridge device contains 4 endpoints
* 1 Control - usual USB stuff + AP -> SVC messages
@@ -600,6 +732,10 @@
if (retval)
goto error;
+ apb1_log_enable_dentry = debugfs_create_file("apb1_log_enable", 666,
+ gb_debugfs_get(), es1,
+ &apb1_log_enable_fops);
+
return 0;
error:
ap_disconnect(interface);