This adds debugfs interface that can be used for debugging possible
hardware/software issues.
It currently exposes the following debugfs entries for each SPI device
probed:
/sys/kernel/debug/pi433/<DEVICE>/regs
...
The 'regs' file contains all rf69 uC registers values that are useful
for troubleshooting misconfigurations between 2 devices. It contains one
register per line so it should be easy to use normal filtering tools to
find the registers of interest if needed.
Signed-off-by: Paulo Miguel Almeida <paulo.miguel.almeida.rodenas@xxxxxxxxx>
---
Changelog:
v3: fix build error, remove redundant comments and validate return values
from wait_event_interruptible routines: Req: Greg K-h, Dan Carpenter
v2: remove redudant references to dentry pointers in the code and perform
debugsfs_lookup instead. Req: Greg k-h
v1: https://lore.kernel.org/lkml/20220123073855.GA79453@xxxxxxxxxxxxxxx/
---
drivers/staging/pi433/pi433_if.c | 75 ++++++++++++++++++++++++++++++++
drivers/staging/pi433/rf69.c | 2 +-
drivers/staging/pi433/rf69.h | 1 +
3 files changed, 77 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/pi433/pi433_if.c b/drivers/staging/pi433/pi433_if.c
index 17ff51f6a..74748d3cd 100644
--- a/drivers/staging/pi433/pi433_if.c
+++ b/drivers/staging/pi433/pi433_if.c
@@ -41,6 +41,8 @@
#ifdef CONFIG_COMPAT
#include <linux/compat.h>
#endif
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
#include "pi433_if.h"
#include "rf69.h"
@@ -1102,12 +1104,75 @@ static const struct file_operations pi433_fops = {
.llseek = no_llseek,
};
+static int pi433_debugfs_regs_show(struct seq_file *m, void *p)
+{
+ struct pi433_device *dev;
+ u8 reg_data[114];
+ int i;
+ char *fmt = "0x%02x, 0x%02x\n";
+ int ret = 0;
+
+ dev = m->private;
+
+ mutex_lock(&dev->tx_fifo_lock);
+ mutex_lock(&dev->rx_lock);
+
+ // wait for on-going operations to finish
+ ret = wait_event_interruptible(dev->rx_wait_queue, !dev->tx_active);
+ if (ret)
+ return ret;
+
+ ret = wait_event_interruptible(dev->tx_wait_queue, !dev->rx_active);
+ if (ret)
+ return ret;
+
+ // skip FIFO register (0x0) otherwise this can affect some of uC ops
+ for (i = 1; i < 0x50; i++)
+ reg_data[i] = rf69_read_reg(dev->spi, i);
+
+ reg_data[REG_TESTLNA] = rf69_read_reg(dev->spi, REG_TESTLNA);
+ reg_data[REG_TESTPA1] = rf69_read_reg(dev->spi, REG_TESTPA1);
+ reg_data[REG_TESTPA2] = rf69_read_reg(dev->spi, REG_TESTPA2);
+ reg_data[REG_TESTDAGC] = rf69_read_reg(dev->spi, REG_TESTDAGC);
+ reg_data[REG_TESTAFC] = rf69_read_reg(dev->spi, REG_TESTAFC);
+
+ seq_puts(m, "# reg, val\n");
+
+ for (i = 1; i < 0x50; i++)
+ seq_printf(m, fmt, i, reg_data[i]);
+
+ seq_printf(m, fmt, REG_TESTLNA, reg_data[REG_TESTLNA]);
+ seq_printf(m, fmt, REG_TESTPA1, reg_data[REG_TESTPA1]);
+ seq_printf(m, fmt, REG_TESTPA2, reg_data[REG_TESTPA2]);
+ seq_printf(m, fmt, REG_TESTDAGC, reg_data[REG_TESTDAGC]);
+ seq_printf(m, fmt, REG_TESTAFC, reg_data[REG_TESTAFC]);
+
+ mutex_unlock(&dev->rx_lock);
+ mutex_unlock(&dev->tx_fifo_lock);
+
+ return ret;
+}
+
+static int pi433_debugfs_regs_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, pi433_debugfs_regs_show, inode->i_private);
+}
+
+static const struct file_operations debugfs_fops = {
+ .llseek = seq_lseek,
+ .open = pi433_debugfs_regs_open,
+ .owner = THIS_MODULE,
+ .read = seq_read,
+ .release = single_release
+};
+
/*-------------------------------------------------------------------------*/
static int pi433_probe(struct spi_device *spi)
{
struct pi433_device *device;
int retval;
+ struct dentry *entry;
/* setup spi parameters */
spi->mode = 0x00;
@@ -1256,6 +1321,10 @@ static int pi433_probe(struct spi_device *spi)
/* spi setup */
spi_set_drvdata(spi, device);
+ entry = debugfs_create_dir(dev_name(device->dev),
+ debugfs_lookup(KBUILD_MODNAME, NULL));
+ debugfs_create_file("regs", 0400, entry, device, &debugfs_fops);
+
return 0;
del_cdev:
@@ -1279,6 +1348,9 @@ static int pi433_probe(struct spi_device *spi)
static int pi433_remove(struct spi_device *spi)
{
struct pi433_device *device = spi_get_drvdata(spi);
+ struct dentry *mod_entry = debugfs_lookup(KBUILD_MODNAME, NULL);
+
+ debugfs_remove(debugfs_lookup(dev_name(device->dev), mod_entry));
/* free GPIOs */
free_gpio(device);
@@ -1353,6 +1425,8 @@ static int __init pi433_init(void)
return PTR_ERR(pi433_class);
}
+ debugfs_create_dir(KBUILD_MODNAME, NULL);
+
status = spi_register_driver(&pi433_spi_driver);
if (status < 0) {
class_destroy(pi433_class);
@@ -1370,6 +1444,7 @@ static void __exit pi433_exit(void)
spi_unregister_driver(&pi433_spi_driver);
class_destroy(pi433_class);
unregister_chrdev(MAJOR(pi433_dev), pi433_spi_driver.driver.name);
+ debugfs_remove_recursive(debugfs_lookup(KBUILD_MODNAME, NULL));
}
module_exit(pi433_exit);
diff --git a/drivers/staging/pi433/rf69.c b/drivers/staging/pi433/rf69.c
index d60514a84..b1a3382f4 100644
--- a/drivers/staging/pi433/rf69.c
+++ b/drivers/staging/pi433/rf69.c
@@ -24,7 +24,7 @@
/*-------------------------------------------------------------------------*/
-static u8 rf69_read_reg(struct spi_device *spi, u8 addr)
+u8 rf69_read_reg(struct spi_device *spi, u8 addr)
{
int retval;
diff --git a/drivers/staging/pi433/rf69.h b/drivers/staging/pi433/rf69.h
index c25942f14..3ff5609ec 100644
--- a/drivers/staging/pi433/rf69.h
+++ b/drivers/staging/pi433/rf69.h
@@ -17,6 +17,7 @@
#define FIFO_SIZE 66 /* bytes */
#define FIFO_THRESHOLD 15 /* bytes */
+u8 rf69_read_reg(struct spi_device *spi, u8 addr);
int rf69_get_version(struct spi_device *spi);
int rf69_set_mode(struct spi_device *spi, enum mode mode);
int rf69_set_data_mode(struct spi_device *spi, u8 data_mode);
--
2.34.1
