[PATCH v2 15/16] misc: support for I-8042 in LP-8x4x

Sergei Ianovich
2013-12-13T02:27:24Z

Status of I-8042 16 digital output channels can be managed via
sysfs.

Status of I-8042 16 digital input channels can be read via sysfs.

http://www.icpdas.com/products/Remote_IO/i-8ke/i-8042w.htm

Signed-off-by: Sergei Ianovich <ynvich@gmail.com>
---
v0..v2
* no changes

Documentation/misc-devices/lp8x4x_bus.txt | 4 ++
drivers/misc/lp8x4x_bus.c | 76 ++++++++++++++++++++++++++++++-
2 files changed, 78 insertions(+), 2 deletions(-)

diff --git a/Documentation/misc-devices/lp8x4x_bus.txt b/Documentation/misc-devices/lp8x4x_bus.txt
index 74df10b..e3a8bcf 100644
--- a/Documentation/misc-devices/lp8x4x_bus.txt
+++ b/Documentation/misc-devices/lp8x4x_bus.txt
@@ -50,6 +50,10 @@ active_slot
model
RO - shows expansion module model number

+input_status
+ RO - get status of digital input channels on the module in
+ the expansion slot.
+
output_status
RW - set status of digital output channels on the module in
the expansion slot. Value can be read back.
diff --git a/drivers/misc/lp8x4x_bus.c b/drivers/misc/lp8x4x_bus.c
index 1ef1726..684e640 100644
--- a/drivers/misc/lp8x4x_bus.c
+++ b/drivers/misc/lp8x4x_bus.c
@@ -27,6 +27,8 @@ struct lp8x4x_slot {
struct mutex lock;
unsigned int DO_len;
u32 DO;
+ unsigned int DI_len;
+ u32 DI;
struct device dev;
};

@@ -89,6 +91,21 @@ static void lp8x4x_slot_release(struct device *dev)
{
}

+static void lp8x4x_slot_get_DI(struct lp8x4x_slot *s)
+{
+ int i;
+ u32 b;
+
+ mutex_lock(&s->lock);
+ s->DI = 0;
+ for (i = 0; i < s->DI_len; i++) {
+ b = ioread8(s->data_addr + 2 * (i + 1));
+ b ^= 0xff;
+ s->DI += b << (i * 8);
+ }
+ mutex_unlock(&s->lock);
+}
+
static void lp8x4x_slot_set_DO(struct lp8x4x_slot *s)
{
int i;
@@ -98,29 +115,70 @@ static void lp8x4x_slot_set_DO(struct lp8x4x_slot *s)
mutex_unlock(&s->lock);
}

+static ssize_t input_status_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct lp8x4x_slot *s = container_of(dev, struct lp8x4x_slot, dev);
+
+ lp8x4x_slot_get_DI(s);
+ switch (s->DI_len) {
+ case 4:
+ return sprintf(buf, "0x%08x\n", s->DI);
+ case 2:
+ return sprintf(buf, "0x%04x\n", s->DI);
+ case 1:
+ return sprintf(buf, "0x%02x\n", s->DI);
+ default:
+ break;
+ }
+ return sprintf(buf, "0x%x\n", s->DI);
+}
+
+static DEVICE_ATTR_RO(input_status);
+
static ssize_t output_status_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct lp8x4x_slot *s = container_of(dev, struct lp8x4x_slot, dev);

- return sprintf(buf, "0x%08x\n", s->DO);
+ switch (s->DO_len) {
+ case 4:
+ return sprintf(buf, "0x%08x\n", s->DO);
+ case 2:
+ return sprintf(buf, "0x%04x\n", s->DO);
+ case 1:
+ return sprintf(buf, "0x%02x\n", s->DO);
+ default:
+ break;
+ }
+ return sprintf(buf, "0x%x\n", s->DO);
}

static ssize_t output_status_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct lp8x4x_slot *s = container_of(dev, struct lp8x4x_slot, dev);
+ u32 DO;
+ u8 *b = (void *) &DO;
+ int i;

if (!buf)
return count;
if (0 == count)
return count;

- if (kstrtouint(buf, 16, &s->DO) != 0) {
+ if (kstrtouint(buf, 16, &DO) != 0) {
dev_err(dev, "bad input\n");
return count;
}

+ for (i = 4; i > s->DO_len; i--)
+ if (b[i - 1] != 0) {
+ dev_err(dev, "bad input\n");
+ return count;
+ }
+
+ s->DO = DO;
lp8x4x_slot_set_DO(s);

return count;
@@ -151,6 +209,14 @@ static struct attribute *do_slot_dev_attrs[] = {
};
ATTRIBUTE_GROUPS(do_slot_dev);

+static struct attribute *dio_slot_dev_attrs[] = {
+ &dev_attr_model.attr,
+ &dev_attr_output_status.attr,
+ &dev_attr_input_status.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(dio_slot_dev);
+
static void lp8x4x_master_release(struct device *dev)
{
struct lp8x4x_master *m = container_of(dev, struct lp8x4x_master, dev);
@@ -255,6 +321,12 @@ static void __init lp8x4x_bus_probe_slot(struct lp8x4x_master *m, int i,
lp8x4x_slot_set_DO(s);
s->dev.groups = do_slot_dev_groups;
break;
+ case 42:
+ s->DI_len = 2;
+ s->DO_len = 2;
+ lp8x4x_slot_set_DO(s);
+ s->dev.groups = dio_slot_dev_groups;
+ break;
default:
s->dev.groups = slot_dev_groups;
break;
--
1.8.4.3