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 <ynv...@gmail.com> --- v2..v3 v0..v2 * no changes (except number 15/16 -> 20/21) 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 68fefde..3ea257d 100644 --- a/Documentation/misc-devices/lp8x4x_bus.txt +++ b/Documentation/misc-devices/lp8x4x_bus.txt @@ -59,6 +59,10 @@ slot_count 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 5af788d..3fb227d 100644 --- a/drivers/misc/lp8x4x_bus.c +++ b/drivers/misc/lp8x4x_bus.c @@ -29,6 +29,8 @@ struct lp8x4x_slot { struct mutex lock; unsigned int DO_len; u32 DO; + unsigned int DI_len; + u32 DI; struct device dev; }; @@ -94,6 +96,21 @@ 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; @@ -103,29 +120,70 @@ 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; @@ -156,6 +214,14 @@ 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); @@ -321,6 +387,12 @@ 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; -- 1.8.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
