On 2/26/21 2:29 AM, William Breathitt Gray wrote:
> 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.gasn...@st.com>
> Cc: Maxime Coquelin <mcoquelin.st...@gmail.com>
> Cc: Alexandre Torgue <alexandre.tor...@st.com>
> Signed-off-by: William Breathitt Gray <vilhelm.g...@gmail.com>
> ---
> Changes in v2:
> - Support an explicit 0 case for function_get()/function_set()
>
> drivers/counter/stm32-timer-cnt.c | 39 ++++++++++++++++++++-----------
> 1 file changed, 25 insertions(+), 14 deletions(-)
Hi William,
Reviewed-by: Fabrice Gasnier <fabrice.gasn...@foss.st.com>
Many thanks for this fix.
Best Regards,
Fabrice
>
> 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 = {
>
