[PATCH 5.10 060/157] counter: stm32-timer-cnt: Report count function when SLAVE_MODE_DISABLED

Greg Kroah-Hartman
2021-03-22T12:45:36Z

From: William Breathitt Gray <vilhelm.gray@gmail.com>

[ Upstream commit fae6f62e6a580b663ecf42c2120a0898deae9137 ]

When in SLAVE_MODE_DISABLED mode, the count still increases if the
counter is enabled because an internal clock is used. This patch fixes
the stm32_count_function_get() and stm32_count_function_set() functions
to properly handle this behavior.

Fixes: ad29937e206f ("counter: Add STM32 Timer quadrature encoder")
Cc: Fabrice Gasnier <fabrice.gasnier@st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20210226012931.161429-1-vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/counter/stm32-timer-cnt.c | 39 ++++++++++++++++++++-----------
1 file changed, 25 insertions(+), 14 deletions(-)

diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
index ef2a974a2f10..cd50dc12bd02 100644
--- a/drivers/counter/stm32-timer-cnt.c
+++ b/drivers/counter/stm32-timer-cnt.c
@@ -44,13 +44,14 @@ struct stm32_timer_cnt {
* @STM32_COUNT_ENCODER_MODE_3: counts on both TI1FP1 and TI2FP2 edges
*/
enum stm32_count_function {
- STM32_COUNT_SLAVE_MODE_DISABLED = -1,
+ STM32_COUNT_SLAVE_MODE_DISABLED,
STM32_COUNT_ENCODER_MODE_1,
STM32_COUNT_ENCODER_MODE_2,
STM32_COUNT_ENCODER_MODE_3,
};

static enum counter_count_function stm32_count_functions[] = {
+ [STM32_COUNT_SLAVE_MODE_DISABLED] = COUNTER_COUNT_FUNCTION_INCREASE,
[STM32_COUNT_ENCODER_MODE_1] = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A,
[STM32_COUNT_ENCODER_MODE_2] = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B,
[STM32_COUNT_ENCODER_MODE_3] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
@@ -90,6 +91,9 @@ static int stm32_count_function_get(struct counter_device *counter,
regmap_read(priv->regmap, TIM_SMCR, &smcr);

switch (smcr & TIM_SMCR_SMS) {
+ case 0:
+ *function = STM32_COUNT_SLAVE_MODE_DISABLED;
+ return 0;
case 1:
*function = STM32_COUNT_ENCODER_MODE_1;
return 0;
@@ -99,9 +103,9 @@ static int stm32_count_function_get(struct counter_device *counter,
case 3:
*function = STM32_COUNT_ENCODER_MODE_3;
return 0;
+ default:
+ return -EINVAL;
}
-
- return -EINVAL;
}

static int stm32_count_function_set(struct counter_device *counter,
@@ -112,6 +116,9 @@ static int stm32_count_function_set(struct counter_device *counter,
u32 cr1, sms;

switch (function) {
+ case STM32_COUNT_SLAVE_MODE_DISABLED:
+ sms = 0;
+ break;
case STM32_COUNT_ENCODER_MODE_1:
sms = 1;
break;
@@ -122,8 +129,7 @@ static int stm32_count_function_set(struct counter_device *counter,
sms = 3;
break;
default:
- sms = 0;
- break;
+ return -EINVAL;
}

/* Store enable status */
@@ -274,31 +280,36 @@ static int stm32_action_get(struct counter_device *counter,
size_t function;
int err;

- /* Default action mode (e.g. STM32_COUNT_SLAVE_MODE_DISABLED) */
- *action = STM32_SYNAPSE_ACTION_NONE;
-
err = stm32_count_function_get(counter, count, &function);
if (err)
- return 0;
+ return err;

switch (function) {
+ case STM32_COUNT_SLAVE_MODE_DISABLED:
+ /* counts on internal clock when CEN=1 */
+ *action = STM32_SYNAPSE_ACTION_NONE;
+ return 0;
case STM32_COUNT_ENCODER_MODE_1:
/* counts up/down on TI1FP1 edge depending on TI2FP2 level */
if (synapse->signal->id == count->synapses[0].signal->id)
*action = STM32_SYNAPSE_ACTION_BOTH_EDGES;
- break;
+ else
+ *action = STM32_SYNAPSE_ACTION_NONE;
+ return 0;
case STM32_COUNT_ENCODER_MODE_2:
/* counts up/down on TI2FP2 edge depending on TI1FP1 level */
if (synapse->signal->id == count->synapses[1].signal->id)
*action = STM32_SYNAPSE_ACTION_BOTH_EDGES;
- break;
+ else
+ *action = STM32_SYNAPSE_ACTION_NONE;
+ return 0;
case STM32_COUNT_ENCODER_MODE_3:
/* counts up/down on both TI1FP1 and TI2FP2 edges */
*action = STM32_SYNAPSE_ACTION_BOTH_EDGES;
- break;
+ return 0;
+ default:
+ return -EINVAL;
}
-
- return 0;
}

static const struct counter_ops stm32_timer_cnt_ops = {
--
2.30.1