Introduce the internal clock signal, used to count when in simple rising
function. Also add the "frequency" extension to the clock signal.
With this patch, signal action reports a consistent state when "increase"
function is used, and the counting frequency:
$ echo increase > function
$ grep -H "" signal*_action
signal0_action:none
signal1_action:none
signal2_action:rising edge
$ echo 1 > enable
$ cat count
25425
$ cat count
44439
$ cat ../signal2/frequency
208877930
Signed-off-by: Fabrice Gasnier <[email protected]>
---
Changes in v5:
- removed NULL write parameter in COUNTER_COMP_FREQUENCY() macro.
Changes in v4:
- Introduce COUNTER_COMP_FREQUENCY() macro as suggested by William in [1]
[1] https://lore.kernel.org/lkml/ZZwm7ZyrL7vFn0Xd@ubuntu-server-vm-macos/
- Remove "Signal" from "Clock Signal" name which is redundant with sysfs
path that already has signal as a name.
Changes in v3:
- split the patch in 3 parts: signal definition becomes a pre-cursor patch,
add the "prescaler" extension in its own patch.
- Move the clock signal at the end of the signals array, so existing
userspace programs that may rely on signal0 being "Channel 1" for
example will remain compatible.
---
drivers/counter/stm32-timer-cnt.c | 53 ++++++++++++++++++++++++++++---
1 file changed, 49 insertions(+), 4 deletions(-)
diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
index c34747d7857e..65b447b42e75 100644
--- a/drivers/counter/stm32-timer-cnt.c
+++ b/drivers/counter/stm32-timer-cnt.c
@@ -23,6 +23,7 @@
#define STM32_CH1_SIG 0
#define STM32_CH2_SIG 1
+#define STM32_CLOCK_SIG 2
struct stm32_timer_regs {
u32 cr1;
@@ -226,6 +227,10 @@ static struct counter_comp stm32_count_ext[] = {
stm32_count_ceiling_write),
};
+static const enum counter_synapse_action stm32_clock_synapse_actions[] = {
+ COUNTER_SYNAPSE_ACTION_RISING_EDGE,
+};
+
static const enum counter_synapse_action stm32_synapse_actions[] = {
COUNTER_SYNAPSE_ACTION_NONE,
COUNTER_SYNAPSE_ACTION_BOTH_EDGES
@@ -246,7 +251,10 @@ static int stm32_action_read(struct counter_device *counter,
switch (function) {
case COUNTER_FUNCTION_INCREASE:
/* counts on internal clock when CEN=1 */
- *action = COUNTER_SYNAPSE_ACTION_NONE;
+ if (synapse->signal->id == STM32_CLOCK_SIG)
+ *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
+ else
+ *action = COUNTER_SYNAPSE_ACTION_NONE;
return 0;
case COUNTER_FUNCTION_QUADRATURE_X2_A:
/* counts up/down on TI1FP1 edge depending on TI2FP2 level */
@@ -264,7 +272,10 @@ static int stm32_action_read(struct counter_device *counter,
return 0;
case COUNTER_FUNCTION_QUADRATURE_X4:
/* counts up/down on both TI1FP1 and TI2FP2 edges */
- *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
+ if (synapse->signal->id == STM32_CH1_SIG || synapse->signal->id == STM32_CH2_SIG)
+ *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
+ else
+ *action = COUNTER_SYNAPSE_ACTION_NONE;
return 0;
default:
return -EINVAL;
@@ -279,7 +290,30 @@ static const struct counter_ops stm32_timer_cnt_ops = {
.action_read = stm32_action_read,
};
+static int stm32_count_clk_get_freq(struct counter_device *counter,
+ struct counter_signal *signal, u64 *freq)
+{
+ struct stm32_timer_cnt *const priv = counter_priv(counter);
+
+ *freq = clk_get_rate(priv->clk);
+
+ return 0;
+}
+
+static struct counter_comp stm32_count_clock_ext[] = {
+ COUNTER_COMP_FREQUENCY(stm32_count_clk_get_freq),
+};
+
static struct counter_signal stm32_signals[] = {
+ /*
+ * Need to declare all the signals as a static array, and keep the signals order here,
+ * even if they're unused or unexisting on some timer instances. It's an abstraction,
+ * e.g. high level view of the counter features.
+ *
+ * Userspace programs may rely on signal0 to be "Channel 1", signal1 to be "Channel 2",
+ * and so on. When a signal is unexisting, the COUNTER_SYNAPSE_ACTION_NONE can be used,
+ * to indicate that a signal doesn't affect the counter.
+ */
{
.id = STM32_CH1_SIG,
.name = "Channel 1"
@@ -287,7 +321,13 @@ static struct counter_signal stm32_signals[] = {
{
.id = STM32_CH2_SIG,
.name = "Channel 2"
- }
+ },
+ {
+ .id = STM32_CLOCK_SIG,
+ .name = "Clock",
+ .ext = stm32_count_clock_ext,
+ .num_ext = ARRAY_SIZE(stm32_count_clock_ext),
+ },
};
static struct counter_synapse stm32_count_synapses[] = {
@@ -300,7 +340,12 @@ static struct counter_synapse stm32_count_synapses[] = {
.actions_list = stm32_synapse_actions,
.num_actions = ARRAY_SIZE(stm32_synapse_actions),
.signal = &stm32_signals[STM32_CH2_SIG]
- }
+ },
+ {
+ .actions_list = stm32_clock_synapse_actions,
+ .num_actions = ARRAY_SIZE(stm32_clock_synapse_actions),
+ .signal = &stm32_signals[STM32_CLOCK_SIG]
+ },
};
static struct counter_count stm32_counts = {
--
2.25.1