[patch -mm 18/20] chardev: GPIO for SCx200 & PC-8736x: display pinvalues in/out in gpio_dump

From: Jim Cromie
Date: Sat Jun 17 2006 - 14:37:55 EST


18/20. patch.viewpins-values

Add current pin settings to gpio_dump() output. This adds the last
'word' to the syslog lines, which displays the input and output values
that the pin is set to.

pc8736x_gpio.0: io00: 0x0044 TS OD PUE EDGE LO DEBOUNCE io:1/1

The 2 values may differ for a number of reasons:
1- the pin output circuitry is diaabled, (as the above 'TS' indicates)
2- it needs a pullup resistor to drive the attached circuit,
3- the external circuit needs a pullup so the open-drain has something
to pull-down
4- the pin is wired to Vcc or Ground

It might be appropriate to add a WARN for 2,3,4, since they could
damage the chip and/or circuit, esp if misconfig goes unnoticed.


Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>

---

diffstat gpio-scx/patch.viewpins-values
nsc_gpio.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)

diff -ruNp -X dontdiff -X exclude-diffs ax-17/drivers/char/nsc_gpio.c ax-18/drivers/char/nsc_gpio.c
--- ax-17/drivers/char/nsc_gpio.c 2006-06-17 01:45:49.000000000 -0600
+++ ax-18/drivers/char/nsc_gpio.c 2006-06-17 01:54:42.000000000 -0600
@@ -26,7 +26,7 @@ void nsc_gpio_dump(struct nsc_gpio_ops *
u32 config = amp->gpio_config(index, ~0, 0);

/* user requested via 'v' command, so its INFO */
- dev_info(amp->dev, "io%02u: 0x%04x %s %s %s %s %s %s %s\n",
+ dev_info(amp->dev, "io%02u: 0x%04x %s %s %s %s %s %s %s\tio:%d/%d\n",
index, config,
(config & 1) ? "OE" : "TS", /* output-enabled/tristate */
(config & 2) ? "PP" : "OD", /* push pull / open drain */
@@ -34,7 +34,9 @@ void nsc_gpio_dump(struct nsc_gpio_ops *
(config & 8) ? "LOCKED" : "", /* locked / unlocked */
(config & 16) ? "LEVEL" : "EDGE",/* level/edge input */
(config & 32) ? "HI" : "LO", /* trigger on rise/fall edge */
- (config & 64) ? "DEBOUNCE" : ""); /* debounce */
+ (config & 64) ? "DEBOUNCE" : "", /* debounce */
+
+ amp->gpio_get(index), amp->gpio_current(index));
}

ssize_t nsc_gpio_write(struct file *file, const char __user *data,


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