On Fri, 22 Jan 2021 15:14:56 +0100, Hui Wang wrote:
--- /dev/null +++ b/Documentation/sound/designs/jack-injection.rst @@ -0,0 +1,124 @@
(snip)
+Explanation for the debugfs nodes: +::
- kctl_id, read-only, get jack_kctl->kctl's id
- sound/card1/Headphone_Jack# cat kctl_id
- Headphone Jack
- mask_bits, read-only, get jack_kctl's supported events mask_bits
- sound/card1/Headphone_Jack# cat mask_bits
- 0x0001 HEADPHONE(0x0001)
- status, read-only, get jack_kctl's current status
- headphone unplugged:
- sound/card1/Headphone_Jack# cat status
- Unplugged
- headphone plugged:
- sound/card1/Headphone_Jack# cat status
- Plugged
- type, read-only, get snd_jack's supported events type (all
- supported events on the physical audio jack)
- sound/card1/Headphone_Jack# cat type
- 0x7803 HEADPHONE(0x0001) MICROPHONE(0x0002) BTN_3(0x0800) BTN_2(0x1000) BTN_1(0x2000) BTN_0(0x4000)
- sw_inject_enable, read-write, enable or disable injection
- injection disabled:
- sound/card1/Headphone_Jack# cat sw_inject_enable
- Jack: Headphone Jack Inject Enabled: 0
- injection enabled:
- sound/card1/Headphone_Jack# cat sw_inject_enable
- Jack: Headphone Jack Inject Enabled: 1
- to enable jack injection:
- sound/card1/Headphone_Jack# echo 1 > sw_inject_enable
- to disable jack injection:
- sound/card1/Headphone_Jack# echo 0 > sw_inject_enable
- jackin_inject, write-only, inject plugin or plugout
- to inject plugin:
- sound/card1/Headphone_Jack# echo 1 > jackin_inject
- to inject plugout:
- sound/card1/Headphone_Jack# echo 0 > jackin_inject
The lists could be better in a normal format, while only the examples with cat and echo should be in verbose format.
diff --git a/sound/core/Kconfig b/sound/core/Kconfig index d4554f376160..a9189f58dc56 100644 --- a/sound/core/Kconfig +++ b/sound/core/Kconfig @@ -38,6 +38,15 @@ config SND_JACK_INPUT_DEV depends on SND_JACK default y if INPUT=y || INPUT=SND
+config SND_JACK_INJECTION_DEBUG
- bool "Sound jack injection interface via debugfs"
- depends on SND_JACK && DEBUG_FS
Also, could depend on SND_DEBUG for consistency.
diff --git a/sound/core/init.c b/sound/core/init.c index 75aec71c48a8..e7f7cfe1143b 100644 --- a/sound/core/init.c +++ b/sound/core/init.c @@ -13,6 +13,7 @@ #include <linux/time.h> #include <linux/ctype.h> #include <linux/pm.h> +#include <linux/debugfs.h> #include <linux/completion.h>
#include <sound/core.h> @@ -161,6 +162,7 @@ int snd_card_new(struct device *parent, int idx, const char *xid, { struct snd_card *card; int err;
char name[8];
if (snd_BUG_ON(!card_ret)) return -EINVAL;
@@ -244,6 +246,10 @@ int snd_card_new(struct device *parent, int idx, const char *xid, dev_err(parent, "unable to create card info\n"); goto __error_ctl; }
- sprintf(name, "card%d", idx);
- card->debugfs_root = debugfs_create_dir(name, sound_debugfs_root);
It's still an open question whether we want to create the debugfs always. But I guess it's OK, we might want to add more stuff to debugfs later. Or, it makes sense to create only if CONFIG_SND_DEBUG=y.
+static ssize_t sw_inject_enable_write(struct file *file,
const char __user *from, size_t count, loff_t *ppos)+{
- struct snd_jack_kctl *jack_kctl = file->private_data;
- int ret, err;
- unsigned long enable;
- char buf[8] = { 0 };
- if (count >= 8)
return -EINVAL;- ret = simple_write_to_buffer(buf, count, ppos, from, count);
The simple_write_to_buffer() doesn't terminate the string by itself, hence you need to make sure the string termination before kstrtoul() call. e.g. buf[sizeof(buf)-1] = 0;
And maybe it's easier to make a helper function to that, since it's called in multiple places.
+static int parse_mask_bits(unsigned int mask_bits, char *s) +{
- char buf[256];
- int len, i;
- len = scnprintf(buf, sizeof(buf), "0x%04x", mask_bits);
- for (i = 0; i < 16; i++)
if (mask_bits & (1 << i))len += scnprintf(buf + strlen(buf), sizeof(buf) - strlen(buf)," %s", jack_events_name[i]);- len += scnprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "\n");
- strcpy(s, buf);
You need to intermediate buffer if you do a full copy here... Just perform the string ops on s with a certain limit. Also, you can use strncat() or strlcat() for simplicity.
thanks,
Takashi