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 644ba18a72ad..c680c7abdd26 100644 --- a/drivers/counter/stm32-timer-cnt.c +++ b/drivers/counter/stm32-timer-cnt.c @@ -35,13 +35,14 @@ 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, @@ -88,6 +89,9 @@ 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; @@ -97,9 +101,9 @@ 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, @@ -110,6 +114,9 @@ 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; @@ -120,8 +127,7 @@ static int stm32_count_function_set(struct counter_device *counter, sms = 3; break; default: - sms = 0; - break; + return -EINVAL; }
/* Store enable status */ @@ -269,31 +275,36 @@ 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 = {