On Sat, 22 Feb 2020 11:49:58 -0500 William Breathitt Gray <vilhelm.gray@xxxxxxxxx> wrote: > The ACCES 104-QUAD-8 series does active filtering on the quadrature > input signals via the PC/104 bus clock (OSC 14.318 MHz). This patch > exposes the filter clock prescaler available on each channel. > > Signed-off-by: William Breathitt Gray <vilhelm.gray@xxxxxxxxx> Looks good to me. Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to poke at it. thanks, Jonathan > --- > .../ABI/testing/sysfs-bus-counter-104-quad-8 | 7 +++ > drivers/counter/104-quad-8.c | 61 ++++++++++++++++++- > 2 files changed, 65 insertions(+), 3 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 b/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 > index 46b1f33b2fce..3c905d3cf5d7 100644 > --- a/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 > +++ b/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 > @@ -1,3 +1,10 @@ > +What: /sys/bus/counter/devices/counterX/signalY/filter_clock_prescaler > +KernelVersion: 5.7 > +Contact: linux-iio@xxxxxxxxxxxxxxx > +Description: > + Filter clock factor for input Signal Y. This prescaler value > + affects the inputs of both quadrature pair signals. > + > What: /sys/bus/counter/devices/counterX/signalY/index_polarity > KernelVersion: 5.2 > Contact: linux-iio@xxxxxxxxxxxxxxx > diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c > index 17e67a84777d..0cfc813ee2cb 100644 > --- a/drivers/counter/104-quad-8.c > +++ b/drivers/counter/104-quad-8.c > @@ -43,6 +43,7 @@ MODULE_PARM_DESC(base, "ACCES 104-QUAD-8 base addresses"); > */ > struct quad8_iio { > struct counter_device counter; > + unsigned int fck_prescaler[QUAD8_NUM_COUNTERS]; > unsigned int preset[QUAD8_NUM_COUNTERS]; > unsigned int count_mode[QUAD8_NUM_COUNTERS]; > unsigned int quadrature_mode[QUAD8_NUM_COUNTERS]; > @@ -84,6 +85,8 @@ struct quad8_iio { > #define QUAD8_RLD_PRESET_CNTR 0x08 > /* Transfer Counter to Output Latch */ > #define QUAD8_RLD_CNTR_OUT 0x10 > +/* Transfer Preset Register LSB to FCK Prescaler */ > +#define QUAD8_RLD_PRESET_PSC 0x18 > #define QUAD8_CHAN_OP_ENABLE_COUNTERS 0x00 > #define QUAD8_CHAN_OP_RESET_COUNTERS 0x01 > #define QUAD8_CMR_QUADRATURE_X1 0x08 > @@ -1140,6 +1143,50 @@ static ssize_t quad8_count_preset_enable_write(struct counter_device *counter, > return len; > } > > +static ssize_t quad8_signal_fck_prescaler_read(struct counter_device *counter, > + struct counter_signal *signal, void *private, char *buf) > +{ > + const struct quad8_iio *const priv = counter->priv; > + const size_t channel_id = signal->id / 2; > + > + return sprintf(buf, "%u\n", priv->fck_prescaler[channel_id]); > +} > + > +static ssize_t quad8_signal_fck_prescaler_write(struct counter_device *counter, > + struct counter_signal *signal, void *private, const char *buf, > + size_t len) > +{ > + struct quad8_iio *const priv = counter->priv; > + const size_t channel_id = signal->id / 2; > + const int base_offset = priv->base + 2 * channel_id; > + u8 prescaler; > + int ret; > + > + ret = kstrtou8(buf, 0, &prescaler); > + if (ret) > + return ret; > + > + priv->fck_prescaler[channel_id] = prescaler; > + > + /* Reset Byte Pointer */ > + outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1); > + > + /* Set filter clock factor */ > + outb(prescaler, base_offset); > + outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_PRESET_PSC, > + base_offset + 1); > + > + return len; > +} > + > +static const struct counter_signal_ext quad8_signal_ext[] = { > + { > + .name = "filter_clock_prescaler", > + .read = quad8_signal_fck_prescaler_read, > + .write = quad8_signal_fck_prescaler_write > + } > +}; > + > static const struct counter_signal_ext quad8_index_ext[] = { > COUNTER_SIGNAL_ENUM("index_polarity", &quad8_index_pol_enum), > COUNTER_SIGNAL_ENUM_AVAILABLE("index_polarity", &quad8_index_pol_enum), > @@ -1147,9 +1194,11 @@ static const struct counter_signal_ext quad8_index_ext[] = { > COUNTER_SIGNAL_ENUM_AVAILABLE("synchronous_mode", &quad8_syn_mode_enum) > }; > > -#define QUAD8_QUAD_SIGNAL(_id, _name) { \ > - .id = (_id), \ > - .name = (_name) \ > +#define QUAD8_QUAD_SIGNAL(_id, _name) { \ > + .id = (_id), \ > + .name = (_name), \ > + .ext = quad8_signal_ext, \ > + .num_ext = ARRAY_SIZE(quad8_signal_ext) \ > } > > #define QUAD8_INDEX_SIGNAL(_id, _name) { \ > @@ -1314,6 +1363,12 @@ static int quad8_probe(struct device *dev, unsigned int id) > base_offset = base[id] + 2 * i; > /* Reset Byte Pointer */ > outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1); > + /* Reset filter clock factor */ > + outb(0, base_offset); > + outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_PRESET_PSC, > + base_offset + 1); > + /* Reset Byte Pointer */ > + outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1); > /* Reset Preset Register */ > for (j = 0; j < 3; j++) > outb(0x00, base_offset);