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author | William Breathitt Gray <vilhelm.gray@gmail.com> | 2020-03-01 17:07:19 -0500 |
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committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2020-03-08 17:28:53 +0000 |
commit | 954ab5cc5f3e0bc764df81a13f065936a85e2084 (patch) | |
tree | 6fdedf1d57baa778361ab6709355af22f7f474a8 /drivers/counter | |
parent | de65d0556343132222a9f48417c2bad82e3a7503 (diff) | |
download | linux-954ab5cc5f3e0bc764df81a13f065936a85e2084.tar.gz linux-954ab5cc5f3e0bc764df81a13f065936a85e2084.tar.bz2 linux-954ab5cc5f3e0bc764df81a13f065936a85e2084.zip |
counter: 104-quad-8: Support Differential Encoder Cable Status
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>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/counter')
-rw-r--r-- | drivers/counter/104-quad-8.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c index 0cfc813ee2cb..9dab190c49b0 100644 --- a/drivers/counter/104-quad-8.c +++ b/drivers/counter/104-quad-8.c @@ -31,6 +31,7 @@ MODULE_PARM_DESC(base, "ACCES 104-QUAD-8 base addresses"); /** * struct quad8_iio - IIO device private data structure * @counter: instance of the counter_device + * @fck_prescaler: array of filter clock prescaler configurations * @preset: array of preset values * @count_mode: array of count mode configurations * @quadrature_mode: array of quadrature mode configurations @@ -39,6 +40,7 @@ MODULE_PARM_DESC(base, "ACCES 104-QUAD-8 base addresses"); * @preset_enable: array of set_to_preset_on_index attribute configurations * @synchronous_mode: array of index function synchronous mode configurations * @index_polarity: array of index function polarity configurations + * @cable_fault_enable: differential encoder cable status enable configurations * @base: base port address of the IIO device */ struct quad8_iio { @@ -52,11 +54,13 @@ struct quad8_iio { unsigned int preset_enable[QUAD8_NUM_COUNTERS]; unsigned int synchronous_mode[QUAD8_NUM_COUNTERS]; unsigned int index_polarity[QUAD8_NUM_COUNTERS]; + unsigned int cable_fault_enable; unsigned int base; }; #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 */ @@ -1143,6 +1147,66 @@ static ssize_t quad8_count_preset_enable_write(struct counter_device *counter, return len; } +static ssize_t quad8_signal_cable_fault_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; + const bool disabled = !(priv->cable_fault_enable & BIT(channel_id)); + unsigned int status; + unsigned int fault; + + if (disabled) + return -EINVAL; + + /* Logic 0 = cable fault */ + status = inb(priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS); + + /* Mask respective channel and invert logic */ + fault = !(status & BIT(channel_id)); + + return sprintf(buf, "%u\n", fault); +} + +static ssize_t quad8_signal_cable_fault_enable_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; + const unsigned int enb = !!(priv->cable_fault_enable & BIT(channel_id)); + + return sprintf(buf, "%u\n", enb); +} + +static ssize_t quad8_signal_cable_fault_enable_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; + bool enable; + int ret; + unsigned int cable_fault_enable; + + ret = kstrtobool(buf, &enable); + if (ret) + return ret; + + if (enable) + priv->cable_fault_enable |= BIT(channel_id); + else + priv->cable_fault_enable &= ~BIT(channel_id); + + /* Enable is active low in Differential Encoder Cable Status register */ + cable_fault_enable = ~priv->cable_fault_enable; + + outb(cable_fault_enable, priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS); + + return len; +} + static ssize_t quad8_signal_fck_prescaler_read(struct counter_device *counter, struct counter_signal *signal, void *private, char *buf) { @@ -1181,6 +1245,15 @@ static ssize_t quad8_signal_fck_prescaler_write(struct counter_device *counter, static const struct counter_signal_ext quad8_signal_ext[] = { { + .name = "cable_fault", + .read = quad8_signal_cable_fault_read + }, + { + .name = "cable_fault_enable", + .read = quad8_signal_cable_fault_enable_read, + .write = quad8_signal_cable_fault_enable_write + }, + { .name = "filter_clock_prescaler", .read = quad8_signal_fck_prescaler_read, .write = quad8_signal_fck_prescaler_write @@ -1383,6 +1456,8 @@ static int quad8_probe(struct device *dev, unsigned int id) /* Disable index function; negative index polarity */ outb(QUAD8_CTR_IDR, base_offset + 1); } + /* Disable Differential Encoder Cable Status for all channels */ + outb(0xFF, base[id] + QUAD8_DIFF_ENCODER_CABLE_STATUS); /* Enable all counters */ outb(QUAD8_CHAN_OP_ENABLE_COUNTERS, base[id] + QUAD8_REG_CHAN_OP); |