[PATCH v4 2/2] counter: microchip-tcb-capture: Add capture extensions for registers RA-RC

Bence Csókás
2025-02-11T15:21:43Z

TCB hardware is capable of capturing the timer value to registers RA and
RB. On top, it is capable of triggering on compare against a third
register, RC. Add these registers as extensions.

Signed-off-by: Bence Csókás <csokas.bence@prolan.hu>
---

Notes:
Changes in v2:
* Add IRQs
Changes in v3:
* Move IRQs to previous patch
Changes in v4:
* Return the status of the regmap_*() operations
* Add names for the extension numbers

drivers/counter/microchip-tcb-capture.c | 62 +++++++++++++++++++
.../linux/counter/microchip-tcb-capture.h | 9 +++
2 files changed, 71 insertions(+)

diff --git a/drivers/counter/microchip-tcb-capture.c b/drivers/counter/microchip-tcb-capture.c
index cc12c2e2113a..369f69aaf14f 100644
--- a/drivers/counter/microchip-tcb-capture.c
+++ b/drivers/counter/microchip-tcb-capture.c
@@ -254,6 +254,66 @@ static int mchp_tc_count_read(struct counter_device *counter,
return 0;
}

+static int mchp_tc_count_cap_read(struct counter_device *counter,
+ struct counter_count *count, size_t idx, u64 *val)
+{
+ struct mchp_tc_data *const priv = counter_priv(counter);
+ u32 cnt;
+ int ret;
+
+ switch (idx) {
+ case COUNTER_MCHP_EXCAP_RA:
+ ret = regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], RA), &cnt);
+ break;
+ case COUNTER_MCHP_EXCAP_RB:
+ ret = regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], RB), &cnt);
+ break;
+ case COUNTER_MCHP_EXCAP_RC:
+ ret = regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], RC), &cnt);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (!ret)
+ *val = cnt;
+
+ return ret;
+}
+
+static int mchp_tc_count_cap_write(struct counter_device *counter,
+ struct counter_count *count, size_t idx, u64 val)
+{
+ struct mchp_tc_data *const priv = counter_priv(counter);
+ int ret;
+
+ if (val > U32_MAX)
+ return -ERANGE;
+
+ switch (idx) {
+ case COUNTER_MCHP_EXCAP_RA:
+ ret = regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], RA), val);
+ break;
+ case COUNTER_MCHP_EXCAP_RB:
+ ret = regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], RB), val);
+ break;
+ case COUNTER_MCHP_EXCAP_RC:
+ ret = regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], RC), val);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return ret;
+}
+
+static DEFINE_COUNTER_ARRAY_CAPTURE(mchp_tc_cnt_cap_array, 3);
+
+static struct counter_comp mchp_tc_count_ext[] = {
+ COUNTER_COMP_ARRAY_CAPTURE(mchp_tc_count_cap_read, mchp_tc_count_cap_write,
+ mchp_tc_cnt_cap_array),
+};
+
static struct counter_count mchp_tc_counts[] = {
{
.id = 0,
@@ -262,6 +322,8 @@ static struct counter_count mchp_tc_counts[] = {
.num_functions = ARRAY_SIZE(mchp_tc_count_functions),
.synapses = mchp_tc_count_synapses,
.num_synapses = ARRAY_SIZE(mchp_tc_count_synapses),
+ .ext = mchp_tc_count_ext,
+ .num_ext = ARRAY_SIZE(mchp_tc_count_ext),
},
};

diff --git a/include/uapi/linux/counter/microchip-tcb-capture.h b/include/uapi/linux/counter/microchip-tcb-capture.h
index b91d8954f06e..0bef1c9d1535 100644
--- a/include/uapi/linux/counter/microchip-tcb-capture.h
+++ b/include/uapi/linux/counter/microchip-tcb-capture.h
@@ -12,6 +12,9 @@
* Count 0
* \__ Synapse 0 -- Signal 0 (Channel A, i.e. TIOA)
* \__ Synapse 1 -- Signal 1 (Channel B, i.e. TIOB)
+ * \__ Extension capture0 (RA register)
+ * \__ Extension capture1 (RB register)
+ * \__ Extension capture2 (RC register)
*
* It also supports the following events:
*
@@ -30,6 +33,12 @@ enum counter_mchp_signals {
COUNTER_MCHP_SIG_TIOB,
};

+enum counter_mchp_capture_extensions {
+ COUNTER_MCHP_EXCAP_RA,
+ COUNTER_MCHP_EXCAP_RB,
+ COUNTER_MCHP_EXCAP_RC,
+};
+
enum counter_mchp_event_channels {
COUNTER_MCHP_EVCHN_CV = 0,
COUNTER_MCHP_EVCHN_RA = 0,
--
2.48.1