Status of I-8042 4 analog output channels can be managed via
sysfs.
http://www.icpdas.com/root/product/solutions/remote_io/rs-485/i-8k_i-87k/i-8024w.html
Signed-off-by: Sergei Ianovich <ynv...@gmail.com>
---
v2..v3
* use usleep_range instead of custom nsleep
* number change (16/16 -> 21/21)
v0..v2
* no changes
Documentation/misc-devices/lp8x4x_bus.txt | 15 ++++++
drivers/misc/lp8x4x_bus.c | 78 +++++++++++++++++++++++++++++++
2 files changed, 93 insertions(+)
diff --git a/Documentation/misc-devices/lp8x4x_bus.txt
b/Documentation/misc-devices/lp8x4x_bus.txt
index 3ea257d..6076e01 100644
--- a/Documentation/misc-devices/lp8x4x_bus.txt
+++ b/Documentation/misc-devices/lp8x4x_bus.txt
@@ -66,3 +66,18 @@ input_status
output_status
RW - set status of digital output channels on the module in
the expansion slot. Value can be read back.
+
+analog_output
+ RW - set status of analog output channels on the module in
+ the expansion slot. Tested with voltage output. Bits 0-13:
+ 0x00c0 is -10.0V
+ 0x2000 is 0.0V
+ 0x3f40 is +10.0V
+
+ So 1 unit of output is 1.25 mV.
+
+ Bits 15 and 14 determine which channel to apply the value:
+ 0x0000 is channel 1
+ 0x4000 is channel 2
+ 0x8000 is channel 3
+ 0xc000 is channel 4
diff --git a/drivers/misc/lp8x4x_bus.c b/drivers/misc/lp8x4x_bus.c
index 3fb227d..72cd0b2 100644
--- a/drivers/misc/lp8x4x_bus.c
+++ b/drivers/misc/lp8x4x_bus.c
@@ -8,6 +8,7 @@
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation or any later version.
*/
+#include <linux/delay.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/init.h>
@@ -23,6 +24,7 @@ MODULE_LICENSE("GPL");
MODULE_AUTHOR("Sergei Ianovich <ynv...@gmail.com>");
MODULE_DESCRIPTION("ICP DAS LP-8x4x parallel bus driver");
+#define LP8X4X_MAX_AO_CHANNELS 4
struct lp8x4x_slot {
void *data_addr;
unsigned int model;
@@ -31,6 +33,8 @@ struct lp8x4x_slot {
u32 DO;
unsigned int DI_len;
u32 DI;
+ unsigned int AO_len;
+ u32 AO[LP8X4X_MAX_AO_CHANNELS];
struct device dev;
};
@@ -120,6 +124,26 @@ static void lp8x4x_slot_set_DO(struct lp8x4x_slot *s)
mutex_unlock(&s->lock);
}
+static void lp8x4x_slot_reset_AO(struct lp8x4x_slot *s)
+{
+ int i;
+ mutex_lock(&s->lock);
+ for (i = 0; i < s->AO_len; i++)
+ s->AO[i] = 0x2000;
+ iowrite8(0x00, s->data_addr);
+ usleep_range(1, 2);
+ iowrite8(0xff, s->data_addr);
+ mutex_unlock(&s->lock);
+}
+
+static void lp8x4x_slot_set_AO(struct lp8x4x_slot *s, u32 val)
+{
+ mutex_lock(&s->lock);
+ iowrite8(val & 0xff, s->data_addr + 2);
+ iowrite8((val >> 8) & 0xff, s->data_addr + 4);
+ mutex_unlock(&s->lock);
+}
+
static ssize_t input_status_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -191,6 +215,48 @@ static ssize_t output_status_store(struct device *dev,
static DEVICE_ATTR_RW(output_status);
+static ssize_t analog_output_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct lp8x4x_slot *s = container_of(dev, struct lp8x4x_slot, dev);
+ int i, c = 0;
+
+ for (i = 0; i < s->AO_len; i++)
+ c += sprintf(&buf[c], "0x%04x\n", s->AO[i]);
+ return c;
+}
+
+static ssize_t analog_output_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 AO;
+ int i;
+
+ if (!buf)
+ return count;
+ if (0 == count)
+ return count;
+
+ if (kstrtouint(buf, 16, &AO) != 0) {
+ dev_err(dev, "bad input\n");
+ return count;
+ }
+
+ if (AO & 0xffff0000) {
+ dev_err(dev, "bad input\n");
+ return count;
+ }
+
+ i = AO >> 14;
+ s->AO[i] = AO & 0x3fff;
+ lp8x4x_slot_set_AO(s, AO);
+
+ return count;
+}
+
+static DEVICE_ATTR_RW(analog_output);
+
static ssize_t model_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -222,6 +288,13 @@ static struct attribute *dio_slot_dev_attrs[] = {
};
ATTRIBUTE_GROUPS(dio_slot_dev);
+static struct attribute *ao_slot_dev_attrs[] = {
+ &dev_attr_model.attr,
+ &dev_attr_analog_output.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(ao_slot_dev);
+
static void lp8x4x_master_release(struct device *dev)
{
struct lp8x4x_master *m = container_of(dev, struct lp8x4x_master, dev);
@@ -382,6 +455,11 @@ static void __init lp8x4x_bus_probe_slot(struct
lp8x4x_master *m, int i,
mutex_init(&s->lock);
switch (model) {
+ case 24:
+ s->AO_len = 4;
+ lp8x4x_slot_reset_AO(s);
+ s->dev.groups = ao_slot_dev_groups;
+ break;
case 41:
s->DO_len = 4;
lp8x4x_slot_set_DO(s);
--
1.8.4.2
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