| Message ID | 20200222154340.89464-1-vilhelm.gray@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | counter: 104-quad-8: Support Differential Encoder Cable Status | expand |
On Sat, 22 Feb 2020 10:43:40 -0500 William Breathitt Gray <vilhelm.gray@gmail.com> wrote: > The ACCES 104-QUAD-8 series provides status information about the > connection state of the differential encoder cable inputs. This patch > implements support to expose such information from these devices. > > Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Hi William, Couple of things on the interface... > --- > .../ABI/testing/sysfs-bus-counter-104-quad-8 | 12 ++++++ > drivers/counter/104-quad-8.c | 38 +++++++++++++++++++ > 2 files changed, 50 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 b/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 > index 46b1f33b2fce..492b3e98f369 100644 > --- a/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 > +++ b/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 > @@ -1,3 +1,15 @@ > +What: /sys/bus/counter/devices/counterX/cable_status > +KernelVersion: 5.7 > +Contact: linux-iio@vger.kernel.org > +Description: > + Differential encoder cable status; bits 0 through 7 > + correspond to channels 1 through 8. Writing a 0 to the > + corresponding bit will enable the status of the > + respective channel. I'm never personally that keen on cases where a sysfs file doesn't have inherent 'obviousness'. In this case we have a bitmap that doesn't make that clear and that also that doesn't have particularly obviously meaning either on the write or read. Hmm. So if you wanted to keep it as a bitmap perhaps something like... cable_test_bitmap So a 1 (or true) would be a successful cable test on read. However that is still not obviously something that needs an enable. It think you need to split it. *_enable *_status Next question is whether it should be a map like this? sysfs rules are usually one value to one sysfs file. It might seem wasteful but I'd like to see something like cable0_test_enable cable0_test_status cable7_test_enable cable7_test_status I haven't thought about whether this could be fit better with the counter ABI but something along those lines! > + > + Logic 0 = cable fault (not connected or loose wires) > + Logic 1 = cable connection good or cable fault disabled > + > What: /sys/bus/counter/devices/counterX/signalY/index_polarity > KernelVersion: 5.2 > Contact: linux-iio@vger.kernel.org > diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c > index 17e67a84777d..1cbaf7e100a3 100644 > --- a/drivers/counter/104-quad-8.c > +++ b/drivers/counter/104-quad-8.c > @@ -56,6 +56,7 @@ struct quad8_iio { > > #define QUAD8_REG_CHAN_OP 0x11 > #define QUAD8_REG_INDEX_INPUT_LEVELS 0x16 > +#define QUAD8_DIFF_ENCODER_CABLE_STATUS 0x17 > /* Borrow Toggle flip-flop */ > #define QUAD8_FLAG_BT BIT(0) > /* Carry Toggle flip-flop */ > @@ -1268,6 +1269,42 @@ static struct counter_count quad8_counts[] = { > QUAD8_COUNT(7, "Channel 8 Count") > }; > > +static ssize_t quad8_cable_status_read(struct counter_device *counter, > + void *private, char *buf) > +{ > + const struct quad8_iio *const priv = counter->priv; > + unsigned int status; > + > + status = inb(priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS); > + > + return sprintf(buf, "0x%X\n", status); > +} > + > +static ssize_t quad8_cable_status_write(struct counter_device *counter, > + void *private, const char *buf, > + size_t len) > +{ > + struct quad8_iio *const priv = counter->priv; > + u8 enable; > + int ret; > + > + ret = kstrtou8(buf, 0, &enable); > + if (ret) > + return ret; > + > + outb(enable, priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS); > + > + return len; > +} > + > +static const struct counter_device_ext quad8_device_ext[] = { > + { > + .name = "cable_status", > + .read = quad8_cable_status_read, > + .write = quad8_cable_status_write > + } > +}; > + > static int quad8_probe(struct device *dev, unsigned int id) > { > struct iio_dev *indio_dev; > @@ -1304,6 +1341,7 @@ static int quad8_probe(struct device *dev, unsigned int id) > quad8iio->counter.num_counts = ARRAY_SIZE(quad8_counts); > quad8iio->counter.signals = quad8_signals; > quad8iio->counter.num_signals = ARRAY_SIZE(quad8_signals); > + quad8iio->counter.ext = quad8_device_ext; > quad8iio->counter.priv = quad8iio; > quad8iio->base = base[id]; >
diff --git a/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 b/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 index 46b1f33b2fce..492b3e98f369 100644 --- a/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 +++ b/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 @@ -1,3 +1,15 @@ +What: /sys/bus/counter/devices/counterX/cable_status +KernelVersion: 5.7 +Contact: linux-iio@vger.kernel.org +Description: + Differential encoder cable status; bits 0 through 7 + correspond to channels 1 through 8. Writing a 0 to the + corresponding bit will enable the status of the + respective channel. + + Logic 0 = cable fault (not connected or loose wires) + Logic 1 = cable connection good or cable fault disabled + What: /sys/bus/counter/devices/counterX/signalY/index_polarity KernelVersion: 5.2 Contact: linux-iio@vger.kernel.org diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c index 17e67a84777d..1cbaf7e100a3 100644 --- a/drivers/counter/104-quad-8.c +++ b/drivers/counter/104-quad-8.c @@ -56,6 +56,7 @@ struct quad8_iio { #define QUAD8_REG_CHAN_OP 0x11 #define QUAD8_REG_INDEX_INPUT_LEVELS 0x16 +#define QUAD8_DIFF_ENCODER_CABLE_STATUS 0x17 /* Borrow Toggle flip-flop */ #define QUAD8_FLAG_BT BIT(0) /* Carry Toggle flip-flop */ @@ -1268,6 +1269,42 @@ static struct counter_count quad8_counts[] = { QUAD8_COUNT(7, "Channel 8 Count") }; +static ssize_t quad8_cable_status_read(struct counter_device *counter, + void *private, char *buf) +{ + const struct quad8_iio *const priv = counter->priv; + unsigned int status; + + status = inb(priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS); + + return sprintf(buf, "0x%X\n", status); +} + +static ssize_t quad8_cable_status_write(struct counter_device *counter, + void *private, const char *buf, + size_t len) +{ + struct quad8_iio *const priv = counter->priv; + u8 enable; + int ret; + + ret = kstrtou8(buf, 0, &enable); + if (ret) + return ret; + + outb(enable, priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS); + + return len; +} + +static const struct counter_device_ext quad8_device_ext[] = { + { + .name = "cable_status", + .read = quad8_cable_status_read, + .write = quad8_cable_status_write + } +}; + static int quad8_probe(struct device *dev, unsigned int id) { struct iio_dev *indio_dev; @@ -1304,6 +1341,7 @@ static int quad8_probe(struct device *dev, unsigned int id) quad8iio->counter.num_counts = ARRAY_SIZE(quad8_counts); quad8iio->counter.signals = quad8_signals; quad8iio->counter.num_signals = ARRAY_SIZE(quad8_signals); + quad8iio->counter.ext = quad8_device_ext; quad8iio->counter.priv = quad8iio; quad8iio->base = base[id];
The ACCES 104-QUAD-8 series provides status information about the connection state of the differential encoder cable inputs. This patch implements support to expose such information from these devices. Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> --- .../ABI/testing/sysfs-bus-counter-104-quad-8 | 12 ++++++ drivers/counter/104-quad-8.c | 38 +++++++++++++++++++ 2 files changed, 50 insertions(+)