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 <ynvich@xxxxxxxxx> --- v3..v4 * no changes 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 <ynvich@xxxxxxxxx>"); 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 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
