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Subject[PATCH 4/4] counter: 104-quad-8: Utilize helper functions to handle PR, FLAG and PSC
Date
The Preset Register (PR), Flag Register (FLAG), and Filter Clock
Prescaler (PSC) have common usage patterns. Wrap up such usage into
dedicated functions to improve code clarity.

Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
drivers/counter/104-quad-8.c | 103 +++++++++++++++--------------------
1 file changed, 45 insertions(+), 58 deletions(-)

diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c
index 796f02fc53b8..27ec905ebe85 100644
--- a/drivers/counter/104-quad-8.c
+++ b/drivers/counter/104-quad-8.c
@@ -241,41 +241,49 @@ static int quad8_count_read(struct counter_device *counter,
return 0;
}

+static void quad8_preset_register_set(struct quad8 *const priv, const size_t id,
+ const unsigned long preset)
+{
+ struct channel_reg __iomem *const chan = priv->reg->channel + id;
+ int i;
+
+ /* Reset Byte Pointer */
+ iowrite8(SELECT_RLD | RESET_BP, &chan->control);
+
+ /* Set Preset Register */
+ for (i = 0; i < 3; i++)
+ iowrite8(preset >> (8 * i), &chan->data);
+}
+
+static void quad8_flag_register_reset(struct quad8 *const priv, const size_t id)
+{
+ struct channel_reg __iomem *const chan = priv->reg->channel + id;
+
+ /* Reset Borrow, Carry, Compare, and Sign flags */
+ iowrite8(SELECT_RLD | RESET_BT_CT_CPT_S_IDX, &chan->control);
+ /* Reset Error flag */
+ iowrite8(SELECT_RLD | RESET_E, &chan->control);
+}
+
static int quad8_count_write(struct counter_device *counter,
struct counter_count *count, u64 val)
{
struct quad8 *const priv = counter_priv(counter);
struct channel_reg __iomem *const chan = priv->reg->channel + count->id;
unsigned long irqflags;
- int i;

if (val > LS7267_CNTR_MAX)
return -ERANGE;

spin_lock_irqsave(&priv->lock, irqflags);

- /* Reset Byte Pointer */
- iowrite8(SELECT_RLD | RESET_BP, &chan->control);
-
/* Counter can only be set via Preset Register */
- for (i = 0; i < 3; i++)
- iowrite8(val >> (8 * i), &chan->data);
-
+ quad8_preset_register_set(priv, count->id, val);
/* Transfer Preset Register to Counter */
iowrite8(SELECT_RLD | TRANSFER_PR_TO_CNTR, &chan->control);
-
- /* Reset Byte Pointer */
- iowrite8(SELECT_RLD | RESET_BP, &chan->control);
-
+ quad8_flag_register_reset(priv, count->id);
/* Set Preset Register back to original value */
- val = priv->preset[count->id];
- for (i = 0; i < 3; i++)
- iowrite8(val >> (8 * i), &chan->data);
-
- /* Reset Borrow, Carry, Compare, and Sign flags */
- iowrite8(SELECT_RLD | RESET_BT_CT_CPT_S_IDX, &chan->control);
- /* Reset Error flag */
- iowrite8(SELECT_RLD | RESET_E, &chan->control);
+ quad8_preset_register_set(priv, count->id, priv->preset[count->id]);

spin_unlock_irqrestore(&priv->lock, irqflags);

@@ -791,22 +799,6 @@ static int quad8_count_preset_read(struct counter_device *counter,
return 0;
}

-static void quad8_preset_register_set(struct quad8 *const priv, const int id,
- const unsigned int preset)
-{
- struct channel_reg __iomem *const chan = priv->reg->channel + id;
- int i;
-
- priv->preset[id] = preset;
-
- /* Reset Byte Pointer */
- iowrite8(SELECT_RLD | RESET_BP, &chan->control);
-
- /* Set Preset Register */
- for (i = 0; i < 3; i++)
- iowrite8(preset >> (8 * i), &chan->data);
-}
-
static int quad8_count_preset_write(struct counter_device *counter,
struct counter_count *count, u64 preset)
{
@@ -818,6 +810,7 @@ static int quad8_count_preset_write(struct counter_device *counter,

spin_lock_irqsave(&priv->lock, irqflags);

+ priv->preset[count->id] = preset;
quad8_preset_register_set(priv, count->id, preset);

spin_unlock_irqrestore(&priv->lock, irqflags);
@@ -864,6 +857,7 @@ static int quad8_count_ceiling_write(struct counter_device *counter,
switch (FIELD_GET(COUNT_MODE, priv->cmr[count->id])) {
case RANGE_LIMIT:
case MODULO_N:
+ priv->preset[count->id] = ceiling;
quad8_preset_register_set(priv, count->id, ceiling);
spin_unlock_irqrestore(&priv->lock, irqflags);
return 0;
@@ -985,25 +979,30 @@ static int quad8_signal_fck_prescaler_read(struct counter_device *counter,
return 0;
}

+static void quad8_filter_clock_prescaler_set(struct quad8 *const priv, const size_t id,
+ const u8 prescaler)
+{
+ struct channel_reg __iomem *const chan = priv->reg->channel + id;
+
+ /* Reset Byte Pointer */
+ iowrite8(SELECT_RLD | RESET_BP, &chan->control);
+ /* Reset filter clock factor */
+ iowrite8(prescaler, &chan->data);
+ iowrite8(SELECT_RLD | TRANSFER_PR0_TO_PSC, &chan->control);
+}
+
static int quad8_signal_fck_prescaler_write(struct counter_device *counter,
struct counter_signal *signal,
u8 prescaler)
{
struct quad8 *const priv = counter_priv(counter);
const size_t channel_id = signal->id / 2;
- struct channel_reg __iomem *const chan = priv->reg->channel + channel_id;
unsigned long irqflags;

spin_lock_irqsave(&priv->lock, irqflags);

priv->fck_prescaler[channel_id] = prescaler;
-
- /* Reset Byte Pointer */
- iowrite8(SELECT_RLD | RESET_BP, &chan->control);
-
- /* Set filter clock factor */
- iowrite8(prescaler, &chan->data);
- iowrite8(SELECT_RLD | RESET_BP | TRANSFER_PR0_TO_PSC, &chan->control);
+ quad8_filter_clock_prescaler_set(priv, channel_id, prescaler);

spin_unlock_irqrestore(&priv->lock, irqflags);

@@ -1203,22 +1202,10 @@ static irqreturn_t quad8_irq_handler(int irq, void *private)
static void quad8_init_counter(struct quad8 *const priv, const size_t channel)
{
struct channel_reg __iomem *const chan = priv->reg->channel + channel;
- unsigned long i;

- /* Reset Byte Pointer */
- iowrite8(SELECT_RLD | RESET_BP, &chan->control);
- /* Reset filter clock factor */
- iowrite8(0, &chan->data);
- iowrite8(SELECT_RLD | RESET_BP | TRANSFER_PR0_TO_PSC, &chan->control);
- /* Reset Byte Pointer */
- iowrite8(SELECT_RLD | RESET_BP, &chan->control);
- /* Reset Preset Register */
- for (i = 0; i < 3; i++)
- iowrite8(0x00, &chan->data);
- /* Reset Borrow, Carry, Compare, and Sign flags */
- iowrite8(SELECT_RLD | RESET_BT_CT_CPT_S_IDX, &chan->control);
- /* Reset Error flag */
- iowrite8(SELECT_RLD | RESET_E, &chan->control);
+ quad8_filter_clock_prescaler_set(priv, channel, 0);
+ quad8_preset_register_set(priv, channel, 0);
+ quad8_flag_register_reset(priv, channel);

/* Binary encoding; Normal count; non-quadrature mode */
priv->cmr[channel] = SELECT_CMR | BINARY | FIELD_PREP(COUNT_MODE, NORMAL_COUNT) |
--
2.39.2
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