[PATCH v3 1/2] counter: Simplify the count_read and count_write callbacks

William Breathitt Gray
2019-09-18T14:23:33Z

The count_read and count_write callbacks are simplified to pass val as
unsigned long rather than as an opaque data structure. The opaque
counter_count_read_value and counter_count_write_value structures,
counter_count_value_type enum, and relevant counter_count_read_value_set
and counter_count_write_value_get functions, are removed as they are no
longer used.

Cc: Patrick Havelange <patrick.havelange@essensium.com>
Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
drivers/counter/104-quad-8.c | 33 +++------
drivers/counter/counter.c | 101 +++++-----------------------
drivers/counter/ftm-quaddec.c | 14 ++--
drivers/counter/stm32-lptimer-cnt.c | 5 +-
drivers/counter/stm32-timer-cnt.c | 17 ++---
include/linux/counter.h | 74 +++-----------------
6 files changed, 45 insertions(+), 199 deletions(-)

diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c
index 00b113f4b958..17e67a84777d 100644
--- a/drivers/counter/104-quad-8.c
+++ b/drivers/counter/104-quad-8.c
@@ -562,11 +562,10 @@ static const struct iio_chan_spec quad8_channels[] = {
};

static int quad8_signal_read(struct counter_device *counter,
- struct counter_signal *signal, struct counter_signal_read_value *val)
+ struct counter_signal *signal, enum counter_signal_value *val)
{
const struct quad8_iio *const priv = counter->priv;
unsigned int state;
- enum counter_signal_level level;

/* Only Index signal levels can be read */
if (signal->id < 16)
@@ -575,22 +574,19 @@ static int quad8_signal_read(struct counter_device *counter,
state = inb(priv->base + QUAD8_REG_INDEX_INPUT_LEVELS)
& BIT(signal->id - 16);

- level = (state) ? COUNTER_SIGNAL_LEVEL_HIGH : COUNTER_SIGNAL_LEVEL_LOW;
-
- counter_signal_read_value_set(val, COUNTER_SIGNAL_LEVEL, &level);
+ *val = (state) ? COUNTER_SIGNAL_HIGH : COUNTER_SIGNAL_LOW;

return 0;
}

static int quad8_count_read(struct counter_device *counter,
- struct counter_count *count, struct counter_count_read_value *val)
+ struct counter_count *count, unsigned long *val)
{
const struct quad8_iio *const priv = counter->priv;
const int base_offset = priv->base + 2 * count->id;
unsigned int flags;
unsigned int borrow;
unsigned int carry;
- unsigned long position;
int i;

flags = inb(base_offset + 1);
@@ -598,36 +594,27 @@ static int quad8_count_read(struct counter_device *counter,
carry = !!(flags & QUAD8_FLAG_CT);

/* Borrow XOR Carry effectively doubles count range */
- position = (unsigned long)(borrow ^ carry) << 24;
+ *val = (unsigned long)(borrow ^ carry) << 24;

/* Reset Byte Pointer; transfer Counter to Output Latch */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_CNTR_OUT,
base_offset + 1);

for (i = 0; i < 3; i++)
- position |= (unsigned long)inb(base_offset) << (8 * i);
-
- counter_count_read_value_set(val, COUNTER_COUNT_POSITION, &position);
+ *val |= (unsigned long)inb(base_offset) << (8 * i);

return 0;
}

static int quad8_count_write(struct counter_device *counter,
- struct counter_count *count, struct counter_count_write_value *val)
+ struct counter_count *count, unsigned long val)
{
const struct quad8_iio *const priv = counter->priv;
const int base_offset = priv->base + 2 * count->id;
- int err;
- unsigned long position;
int i;

- err = counter_count_write_value_get(&position, COUNTER_COUNT_POSITION,
- val);
- if (err)
- return err;
-
/* Only 24-bit values are supported */
- if (position > 0xFFFFFF)
+ if (val > 0xFFFFFF)
return -EINVAL;

/* Reset Byte Pointer */
@@ -635,7 +622,7 @@ static int quad8_count_write(struct counter_device *counter,

/* Counter can only be set via Preset Register */
for (i = 0; i < 3; i++)
- outb(position >> (8 * i), base_offset);
+ outb(val >> (8 * i), base_offset);

/* Transfer Preset Register to Counter */
outb(QUAD8_CTR_RLD | QUAD8_RLD_PRESET_CNTR, base_offset + 1);
@@ -644,9 +631,9 @@ static int quad8_count_write(struct counter_device *counter,
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);

/* Set Preset Register back to original value */
- position = priv->preset[count->id];
+ val = priv->preset[count->id];
for (i = 0; i < 3; i++)
- outb(position >> (8 * i), base_offset);
+ outb(val >> (8 * i), base_offset);

/* Reset Borrow, Carry, Compare, and Sign flags */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, base_offset + 1);
diff --git a/drivers/counter/counter.c b/drivers/counter/counter.c
index 106bc7180cd8..6a683d086008 100644
--- a/drivers/counter/counter.c
+++ b/drivers/counter/counter.c
@@ -220,86 +220,6 @@ ssize_t counter_device_enum_available_read(struct counter_device *counter,
}
EXPORT_SYMBOL_GPL(counter_device_enum_available_read);

-static const char *const counter_signal_level_str[] = {
- [COUNTER_SIGNAL_LEVEL_LOW] = "low",
- [COUNTER_SIGNAL_LEVEL_HIGH] = "high"
-};
-
-/**
- * counter_signal_read_value_set - set counter_signal_read_value data
- * @val: counter_signal_read_value structure to set
- * @type: property Signal data represents
- * @data: Signal data
- *
- * This function sets an opaque counter_signal_read_value structure with the
- * provided Signal data.
- */
-void counter_signal_read_value_set(struct counter_signal_read_value *const val,
- const enum counter_signal_value_type type,
- void *const data)
-{
- if (type == COUNTER_SIGNAL_LEVEL)
- val->len = sprintf(val->buf, "%s\n",
- counter_signal_level_str[*(enum counter_signal_level *)data]);
- else
- val->len = 0;
-}
-EXPORT_SYMBOL_GPL(counter_signal_read_value_set);
-
-/**
- * counter_count_read_value_set - set counter_count_read_value data
- * @val: counter_count_read_value structure to set
- * @type: property Count data represents
- * @data: Count data
- *
- * This function sets an opaque counter_count_read_value structure with the
- * provided Count data.
- */
-void counter_count_read_value_set(struct counter_count_read_value *const val,
- const enum counter_count_value_type type,
- void *const data)
-{
- switch (type) {
- case COUNTER_COUNT_POSITION:
- val->len = sprintf(val->buf, "%lu\n", *(unsigned long *)data);
- break;
- default:
- val->len = 0;
- }
-}
-EXPORT_SYMBOL_GPL(counter_count_read_value_set);
-
-/**
- * counter_count_write_value_get - get counter_count_write_value data
- * @data: Count data
- * @type: property Count data represents
- * @val: counter_count_write_value structure containing data
- *
- * This function extracts Count data from the provided opaque
- * counter_count_write_value structure and stores it at the address provided by
- * @data.
- *
- * RETURNS:
- * 0 on success, negative error number on failure.
- */
-int counter_count_write_value_get(void *const data,
- const enum counter_count_value_type type,
- const struct counter_count_write_value *const val)
-{
- int err;
-
- switch (type) {
- case COUNTER_COUNT_POSITION:
- err = kstrtoul(val->buf, 0, data);
- if (err)
- return err;
- break;
- }
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(counter_count_write_value_get);
-
struct counter_attr_parm {
struct counter_device_attr_group *group;
const char *prefix;
@@ -369,6 +289,11 @@ struct counter_signal_unit {
struct counter_signal *signal;
};

+static const char *const counter_signal_value_str[] = {
+ [COUNTER_SIGNAL_LOW] = "low",
+ [COUNTER_SIGNAL_HIGH] = "high"
+};
+
static ssize_t counter_signal_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -377,13 +302,13 @@ static ssize_t counter_signal_show(struct device *dev,
const struct counter_signal_unit *const component = devattr->component;
struct counter_signal *const signal = component->signal;
int err;
- struct counter_signal_read_value val = { .buf = buf };
+ enum counter_signal_value val;

err = counter->ops->signal_read(counter, signal, &val);
if (err)
return err;

- return val.len;
+ return sprintf(buf, "%s\n", counter_signal_value_str[val]);
}

struct counter_name_unit {
@@ -788,13 +713,13 @@ static ssize_t counter_count_show(struct device *dev,
const struct counter_count_unit *const component = devattr->component;
struct counter_count *const count = component->count;
int err;
- struct counter_count_read_value val = { .buf = buf };
+ unsigned long val;

err = counter->ops->count_read(counter, count, &val);
if (err)
return err;

- return val.len;
+ return sprintf(buf, "%lu\n", val);
}

static ssize_t counter_count_store(struct device *dev,
@@ -806,9 +731,13 @@ static ssize_t counter_count_store(struct device *dev,
const struct counter_count_unit *const component = devattr->component;
struct counter_count *const count = component->count;
int err;
- struct counter_count_write_value val = { .buf = buf };
+ unsigned long val;
+
+ err = kstrtoul(buf, 0, &val);
+ if (err)
+ return err;

- err = counter->ops->count_write(counter, count, &val);
+ err = counter->ops->count_write(counter, count, val);
if (err)
return err;

diff --git a/drivers/counter/ftm-quaddec.c b/drivers/counter/ftm-quaddec.c
index 4046aa9f9234..c2b3fdfd8b77 100644
--- a/drivers/counter/ftm-quaddec.c
+++ b/drivers/counter/ftm-quaddec.c
@@ -178,31 +178,25 @@ static const enum counter_count_function ftm_quaddec_count_functions[] = {

static int ftm_quaddec_count_read(struct counter_device *counter,
struct counter_count *count,
- struct counter_count_read_value *val)
+ unsigned long *val)
{
struct ftm_quaddec *const ftm = counter->priv;
uint32_t cntval;

ftm_read(ftm, FTM_CNT, &cntval);

- counter_count_read_value_set(val, COUNTER_COUNT_POSITION, &cntval);
+ *val = cntval;

return 0;
}

static int ftm_quaddec_count_write(struct counter_device *counter,
struct counter_count *count,
- struct counter_count_write_value *val)
+ const unsigned long val)
{
struct ftm_quaddec *const ftm = counter->priv;
- u32 cnt;
- int err;

- err = counter_count_write_value_get(&cnt, COUNTER_COUNT_POSITION, val);
- if (err)
- return err;
-
- if (cnt != 0) {
+ if (val != 0) {
dev_warn(&ftm->pdev->dev, "Can only accept '0' as new counter value\n");
return -EINVAL;
}
diff --git a/drivers/counter/stm32-lptimer-cnt.c b/drivers/counter/stm32-lptimer-cnt.c
index bbc930a5962c..73bb773f5e6d 100644
--- a/drivers/counter/stm32-lptimer-cnt.c
+++ b/drivers/counter/stm32-lptimer-cnt.c
@@ -377,8 +377,7 @@ static enum counter_synapse_action stm32_lptim_cnt_synapse_actions[] = {
};

static int stm32_lptim_cnt_read(struct counter_device *counter,
- struct counter_count *count,
- struct counter_count_read_value *val)
+ struct counter_count *count, unsigned long *val)
{
struct stm32_lptim_cnt *const priv = counter->priv;
u32 cnt;
@@ -388,7 +387,7 @@ static int stm32_lptim_cnt_read(struct counter_device *counter,
if (ret)
return ret;

- counter_count_read_value_set(val, COUNTER_COUNT_POSITION, &cnt);
+ *val = cnt;

return 0;
}
diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
index 644ba18a72ad..839083543323 100644
--- a/drivers/counter/stm32-timer-cnt.c
+++ b/drivers/counter/stm32-timer-cnt.c
@@ -48,34 +48,27 @@ static enum counter_count_function stm32_count_functions[] = {
};

static int stm32_count_read(struct counter_device *counter,
- struct counter_count *count,
- struct counter_count_read_value *val)
+ struct counter_count *count, unsigned long *val)
{
struct stm32_timer_cnt *const priv = counter->priv;
u32 cnt;

regmap_read(priv->regmap, TIM_CNT, &cnt);
- counter_count_read_value_set(val, COUNTER_COUNT_POSITION, &cnt);
+ *val = cnt;

return 0;
}

static int stm32_count_write(struct counter_device *counter,
struct counter_count *count,
- struct counter_count_write_value *val)
+ const unsigned long val)
{
struct stm32_timer_cnt *const priv = counter->priv;
- u32 cnt;
- int err;
-
- err = counter_count_write_value_get(&cnt, COUNTER_COUNT_POSITION, val);
- if (err)
- return err;

- if (cnt > priv->ceiling)
+ if (val > priv->ceiling)
return -EINVAL;

- return regmap_write(priv->regmap, TIM_CNT, cnt);
+ return regmap_write(priv->regmap, TIM_CNT, val);
}

static int stm32_count_function_get(struct counter_device *counter,
diff --git a/include/linux/counter.h b/include/linux/counter.h
index a061cdcdef7c..32fb4d8cc3fd 100644
--- a/include/linux/counter.h
+++ b/include/linux/counter.h
@@ -290,53 +290,22 @@ struct counter_device_state {
const struct attribute_group **groups;
};

-/**
- * struct counter_signal_read_value - Opaque Signal read value
- * @buf: string representation of Signal read value
- * @len: length of string in @buf
- */
-struct counter_signal_read_value {
- char *buf;
- size_t len;
-};
-
-/**
- * struct counter_count_read_value - Opaque Count read value
- * @buf: string representation of Count read value
- * @len: length of string in @buf
- */
-struct counter_count_read_value {
- char *buf;
- size_t len;
-};
-
-/**
- * struct counter_count_write_value - Opaque Count write value
- * @buf: string representation of Count write value
- */
-struct counter_count_write_value {
- const char *buf;
+enum counter_signal_value {
+ COUNTER_SIGNAL_LOW = 0,
+ COUNTER_SIGNAL_HIGH
};

/**
* struct counter_ops - Callbacks from driver
* @signal_read: optional read callback for Signal attribute. The read
* value of the respective Signal should be passed back via
- * the val parameter. val points to an opaque type which
- * should be set only by calling the
- * counter_signal_read_value_set function from within the
- * signal_read callback.
+ * the val parameter.
* @count_read: optional read callback for Count attribute. The read
* value of the respective Count should be passed back via
- * the val parameter. val points to an opaque type which
- * should be set only by calling the
- * counter_count_read_value_set function from within the
- * count_read callback.
+ * the val parameter.
* @count_write: optional write callback for Count attribute. The write
* value for the respective Count is passed in via the val
- * parameter. val points to an opaque type which should be
- * accessed only by calling the
- * counter_count_write_value_get function.
+ * parameter.
* @function_get: function to get the current count function mode. Returns
* 0 on success and negative error code on error. The index
* of the respective Count's returned function mode should
@@ -355,13 +324,11 @@ struct counter_count_write_value {
struct counter_ops {
int (*signal_read)(struct counter_device *counter,
struct counter_signal *signal,
- struct counter_signal_read_value *val);
+ enum counter_signal_value *val);
int (*count_read)(struct counter_device *counter,
- struct counter_count *count,
- struct counter_count_read_value *val);
+ struct counter_count *count, unsigned long *val);
int (*count_write)(struct counter_device *counter,
- struct counter_count *count,
- struct counter_count_write_value *val);
+ struct counter_count *count, unsigned long val);
int (*function_get)(struct counter_device *counter,
struct counter_count *count, size_t *function);
int (*function_set)(struct counter_device *counter,
@@ -477,29 +444,6 @@ struct counter_device {
void *priv;
};

-enum counter_signal_level {
- COUNTER_SIGNAL_LEVEL_LOW = 0,
- COUNTER_SIGNAL_LEVEL_HIGH
-};
-
-enum counter_signal_value_type {
- COUNTER_SIGNAL_LEVEL = 0
-};
-
-enum counter_count_value_type {
- COUNTER_COUNT_POSITION = 0,
-};
-
-void counter_signal_read_value_set(struct counter_signal_read_value *const val,
- const enum counter_signal_value_type type,
- void *const data);
-void counter_count_read_value_set(struct counter_count_read_value *const val,
- const enum counter_count_value_type type,
- void *const data);
-int counter_count_write_value_get(void *const data,
- const enum counter_count_value_type type,
- const struct counter_count_write_value *const val);
-
int counter_register(struct counter_device *const counter);
void counter_unregister(struct counter_device *const counter);
int devm_counter_register(struct device *dev,
--
2.23.0