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greybus: Dump log from APB1

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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>
This commit is contained in:
Alexandre Bailon 2015-03-23 17:52:37 +01:00 committed by Greg Kroah-Hartman
parent 337b068722
commit 59e3344461
1 changed files with 136 additions and 0 deletions
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136
drivers/staging/greybus/es1.c
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@ -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 @@ static const struct usb_device_id id_table[] = {
};
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 inline struct es1_ap_dev *hd_to_es1(struct greybus_host_device *hd)
}
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 @@ static void ap_disconnect(struct usb_interface *interface)
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 cport_out_callback(struct urb *urb)
*/
}
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 @@ static int ap_probe(struct usb_interface *interface,
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);