[PATCH 2/2] iio: 104-quad-8: Provide defines for magic numbers
From: William Breathitt Gray
Date: Fri May 25 2018 - 07:55:11 EST
This patch adds several register and bit defines to help improve the
clarity of the code by cleaning up magic numbers throughout the driver
source code.
Signed-off-by: William Breathitt Gray <vilhelm.gray@xxxxxxxxx>
---
drivers/iio/counter/104-quad-8.c | 86 ++++++++++++++++++++++----------
1 file changed, 60 insertions(+), 26 deletions(-)
diff --git a/drivers/iio/counter/104-quad-8.c b/drivers/iio/counter/104-quad-8.c
index 4be85ec54af4..7d605d783051 100644
--- a/drivers/iio/counter/104-quad-8.c
+++ b/drivers/iio/counter/104-quad-8.c
@@ -59,6 +59,39 @@ struct quad8_iio {
unsigned int base;
};
+#define REG_CHANNEL_OPERATION 0x11
+#define REG_INDEX_INPUT_LEVELS 0x16
+/* Borrow Toggle flip-flop */
+#define FLAG_BT BIT(0)
+/* Carry Toggle flip-flop */
+#define FLAG_CT BIT(1)
+/* Error flag */
+#define FLAG_E BIT(4)
+/* Up/Down flag */
+#define FLAG_UD BIT(5)
+/* Reset and Load Signal Decoders */
+#define CTR_RLD 0x00
+/* Counter Mode Register */
+#define CTR_CMR 0x20
+/* Input / Output Control Register */
+#define CTR_IOR 0x40
+/* Index Control Register */
+#define CTR_IDR 0x60
+/* Reset Byte Pointer (three byte data pointer) */
+#define RLD_RESET_BP 0x01
+/* Reset Counter */
+#define RLD_RESET_CNTR 0x02
+/* Reset Borrow Toggle, Carry Toggle, Compare Toggle, and Sign flags */
+#define RLD_RESET_FLAGS 0x04
+/* Reset Error flag */
+#define RLD_RESET_E 0x06
+/* Preset Register to Counter */
+#define RLD_PRESET_CNTR 0x08
+/* Transfer Counter to Output Latch */
+#define RLD_CNTR_OUT 0x10
+#define CHAN_OP_ENABLE_COUNTERS 0x00
+#define CHAN_OP_RESET_COUNTERS 0x01
+
static int quad8_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val, int *val2, long mask)
{
@@ -72,19 +105,20 @@ static int quad8_read_raw(struct iio_dev *indio_dev,
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (chan->type == IIO_INDEX) {
- *val = !!(inb(priv->base + 0x16) & BIT(chan->channel));
+ *val = !!(inb(priv->base + REG_INDEX_INPUT_LEVELS)
+ & BIT(chan->channel));
return IIO_VAL_INT;
}
flags = inb(base_offset + 1);
- borrow = flags & BIT(0);
- carry = !!(flags & BIT(1));
+ borrow = flags & FLAG_BT;
+ carry = !!(flags & FLAG_CT);
/* Borrow XOR Carry effectively doubles count range */
*val = (borrow ^ carry) << 24;
/* Reset Byte Pointer; transfer Counter to Output Latch */
- outb(0x11, base_offset + 1);
+ outb(CTR_RLD | RLD_RESET_BP | RLD_CNTR_OUT, base_offset + 1);
for (i = 0; i < 3; i++)
*val |= (unsigned int)inb(base_offset) << (8 * i);
@@ -120,17 +154,17 @@ static int quad8_write_raw(struct iio_dev *indio_dev,
return -EINVAL;
/* Reset Byte Pointer */
- outb(0x01, base_offset + 1);
+ outb(CTR_RLD | RLD_RESET_BP, base_offset + 1);
/* Counter can only be set via Preset Register */
for (i = 0; i < 3; i++)
outb(val >> (8 * i), base_offset);
/* Transfer Preset Register to Counter */
- outb(0x08, base_offset + 1);
+ outb(CTR_RLD | RLD_PRESET_CNTR, base_offset + 1);
/* Reset Byte Pointer */
- outb(0x01, base_offset + 1);
+ outb(CTR_RLD | RLD_RESET_BP, base_offset + 1);
/* Set Preset Register back to original value */
val = priv->preset[chan->channel];
@@ -138,9 +172,9 @@ static int quad8_write_raw(struct iio_dev *indio_dev,
outb(val >> (8 * i), base_offset);
/* Reset Borrow, Carry, Compare, and Sign flags */
- outb(0x04, base_offset + 1);
+ outb(CTR_RLD | RLD_RESET_FLAGS, base_offset + 1);
/* Reset Error flag */
- outb(0x06, base_offset + 1);
+ outb(CTR_RLD | RLD_RESET_E, base_offset + 1);
return 0;
case IIO_CHAN_INFO_ENABLE:
@@ -153,7 +187,7 @@ static int quad8_write_raw(struct iio_dev *indio_dev,
ior_cfg = val | priv->preset_enable[chan->channel] << 1;
/* Load I/O control configuration */
- outb(0x40 | ior_cfg, base_offset + 1);
+ outb(CTR_IOR | ior_cfg, base_offset + 1);
return 0;
case IIO_CHAN_INFO_SCALE:
@@ -217,7 +251,7 @@ static ssize_t quad8_write_preset(struct iio_dev *indio_dev, uintptr_t private,
priv->preset[chan->channel] = preset;
/* Reset Byte Pointer */
- outb(0x01, base_offset + 1);
+ outb(CTR_RLD | RLD_RESET_BP, base_offset + 1);
/* Set Preset Register */
for (i = 0; i < 3; i++)
@@ -258,7 +292,7 @@ static ssize_t quad8_write_set_to_preset_on_index(struct iio_dev *indio_dev,
(unsigned int)preset_enable << 1;
/* Load I/O control configuration to Input / Output Control Register */
- outb(0x40 | ior_cfg, base_offset);
+ outb(CTR_IOR | ior_cfg, base_offset);
return len;
}
@@ -274,7 +308,7 @@ static int quad8_get_noise_error(struct iio_dev *indio_dev,
struct quad8_iio *const priv = iio_priv(indio_dev);
const int base_offset = priv->base + 2 * chan->channel + 1;
- return !!(inb(base_offset) & BIT(4));
+ return !!(inb(base_offset) & FLAG_E);
}
static const struct iio_enum quad8_noise_error_enum = {
@@ -294,7 +328,7 @@ static int quad8_get_count_direction(struct iio_dev *indio_dev,
struct quad8_iio *const priv = iio_priv(indio_dev);
const int base_offset = priv->base + 2 * chan->channel + 1;
- return !!(inb(base_offset) & BIT(5));
+ return !!(inb(base_offset) & FLAG_UD);
}
static const struct iio_enum quad8_count_direction_enum = {
@@ -324,7 +358,7 @@ static int quad8_set_count_mode(struct iio_dev *indio_dev,
mode_cfg |= (priv->quadrature_scale[chan->channel] + 1) << 3;
/* Load mode configuration to Counter Mode Register */
- outb(0x20 | mode_cfg, base_offset);
+ outb(CTR_CMR | mode_cfg, base_offset);
return 0;
}
@@ -364,7 +398,7 @@ static int quad8_set_synchronous_mode(struct iio_dev *indio_dev,
priv->synchronous_mode[chan->channel] = synchronous_mode;
/* Load Index Control configuration to Index Control Register */
- outb(0x60 | idr_cfg, base_offset);
+ outb(CTR_IDR | idr_cfg, base_offset);
return 0;
}
@@ -410,7 +444,7 @@ static int quad8_set_quadrature_mode(struct iio_dev *indio_dev,
priv->quadrature_mode[chan->channel] = quadrature_mode;
/* Load mode configuration to Counter Mode Register */
- outb(0x20 | mode_cfg, base_offset);
+ outb(CTR_CMR | mode_cfg, base_offset);
return 0;
}
@@ -446,7 +480,7 @@ static int quad8_set_index_polarity(struct iio_dev *indio_dev,
priv->index_polarity[chan->channel] = index_polarity;
/* Load Index Control configuration to Index Control Register */
- outb(0x60 | idr_cfg, base_offset);
+ outb(CTR_IDR | idr_cfg, base_offset);
return 0;
}
@@ -556,28 +590,28 @@ static int quad8_probe(struct device *dev, unsigned int id)
priv->base = base[id];
/* Reset all counters and disable interrupt function */
- outb(0x01, base[id] + 0x11);
+ outb(CHAN_OP_RESET_COUNTERS, base[id] + REG_CHANNEL_OPERATION);
/* Set initial configuration for all counters */
for (i = 0; i < QUAD8_NUM_COUNTERS; i++) {
base_offset = base[id] + 2 * i;
/* Reset Byte Pointer */
- outb(0x01, base_offset + 1);
+ outb(CTR_RLD | RLD_RESET_BP, base_offset + 1);
/* Reset Preset Register */
for (j = 0; j < 3; j++)
outb(0x00, base_offset);
/* Reset Borrow, Carry, Compare, and Sign flags */
- outb(0x04, base_offset + 1);
+ outb(CTR_RLD | RLD_RESET_FLAGS, base_offset + 1);
/* Reset Error flag */
- outb(0x06, base_offset + 1);
+ outb(CTR_RLD | RLD_RESET_E, base_offset + 1);
/* Binary encoding; Normal count; non-quadrature mode */
- outb(0x20, base_offset + 1);
+ outb(CTR_CMR, base_offset + 1);
/* Disable A and B inputs; preset on index; FLG1 as Carry */
- outb(0x40, base_offset + 1);
+ outb(CTR_IOR, base_offset + 1);
/* Disable index function; negative index polarity */
- outb(0x60, base_offset + 1);
+ outb(CTR_IDR, base_offset + 1);
}
/* Enable all counters */
- outb(0x00, base[id] + 0x11);
+ outb(CHAN_OP_ENABLE_COUNTERS, base[id] + REG_CHANNEL_OPERATION);
return devm_iio_device_register(dev, indio_dev);
}
--
2.17.0