[PATCH v14 02/17] counter: Return error code on invalid modes
Jonathan Cameron
jic23 at kernel.org
Sun Aug 8 10:07:11 PDT 2021
On Tue, 3 Aug 2021 21:06:12 +0900
William Breathitt Gray <vilhelm.gray at gmail.com> wrote:
> Only a select set of modes (function, action, etc.) are valid for a
> given device configuration. This patch ensures that invalid modes result
> in a return -EINVAL. Such a situation should never occur in reality, but
> it's good to define a default switch case for the sake of making the
> intent of the code clear.
>
> Cc: Kamel Bouhara <kamel.bouhara at bootlin.com>
> Cc: Maxime Coquelin <mcoquelin.stm32 at gmail.com>
> Cc: Alexandre Torgue <alexandre.torgue at st.com>
> Acked-by: David Lechner <david at lechnology.com>
> Acked-by: Syed Nayyar Waris <syednwaris at gmail.com>
> Reviewed-by: Fabrice Gasnier <fabrice.gasnier at foss.st.com>
> Signed-off-by: William Breathitt Gray <vilhelm.gray at gmail.com>
Applied,
Thanks,
> ---
> drivers/counter/104-quad-8.c | 20 ++++++++++++------
> drivers/counter/microchip-tcb-capture.c | 6 ++++++
> drivers/counter/stm32-lptimer-cnt.c | 10 +++++----
> drivers/counter/ti-eqep.c | 27 +++++++++++++++----------
> 4 files changed, 42 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c
> index 81f9642777fb..b358b2b2b883 100644
> --- a/drivers/counter/104-quad-8.c
> +++ b/drivers/counter/104-quad-8.c
> @@ -273,6 +273,10 @@ static int quad8_function_set(struct counter_device *counter,
> *scale = 2;
> mode_cfg |= QUAD8_CMR_QUADRATURE_X4;
> break;
> + default:
> + /* should never reach this path */
> + mutex_unlock(&priv->lock);
> + return -EINVAL;
> }
> }
>
> @@ -349,7 +353,7 @@ static int quad8_action_get(struct counter_device *counter,
> case QUAD8_COUNT_FUNCTION_PULSE_DIRECTION:
> if (synapse->signal->id == signal_a_id)
> *action = QUAD8_SYNAPSE_ACTION_RISING_EDGE;
> - break;
> + return 0;
> case QUAD8_COUNT_FUNCTION_QUADRATURE_X1:
> if (synapse->signal->id == signal_a_id) {
> quad8_direction_get(counter, count, &direction);
> @@ -359,17 +363,18 @@ static int quad8_action_get(struct counter_device *counter,
> else
> *action = QUAD8_SYNAPSE_ACTION_FALLING_EDGE;
> }
> - break;
> + return 0;
> case QUAD8_COUNT_FUNCTION_QUADRATURE_X2:
> if (synapse->signal->id == signal_a_id)
> *action = QUAD8_SYNAPSE_ACTION_BOTH_EDGES;
> - break;
> + return 0;
> case QUAD8_COUNT_FUNCTION_QUADRATURE_X4:
> *action = QUAD8_SYNAPSE_ACTION_BOTH_EDGES;
> - break;
> + return 0;
> + default:
> + /* should never reach this path */
> + return -EINVAL;
> }
> -
> - return 0;
> }
>
> static const struct counter_ops quad8_ops = {
> @@ -529,6 +534,9 @@ static int quad8_count_mode_set(struct counter_device *counter,
> case COUNTER_COUNT_MODE_MODULO_N:
> cnt_mode = 3;
> break;
> + default:
> + /* should never reach this path */
> + return -EINVAL;
> }
>
> mutex_lock(&priv->lock);
> diff --git a/drivers/counter/microchip-tcb-capture.c b/drivers/counter/microchip-tcb-capture.c
> index 51b8af80f98b..0c9a61962911 100644
> --- a/drivers/counter/microchip-tcb-capture.c
> +++ b/drivers/counter/microchip-tcb-capture.c
> @@ -133,6 +133,9 @@ static int mchp_tc_count_function_set(struct counter_device *counter,
> bmr |= ATMEL_TC_QDEN | ATMEL_TC_POSEN;
> cmr |= ATMEL_TC_ETRGEDG_RISING | ATMEL_TC_ABETRG | ATMEL_TC_XC0;
> break;
> + default:
> + /* should never reach this path */
> + return -EINVAL;
> }
>
> regmap_write(priv->regmap, ATMEL_TC_BMR, bmr);
> @@ -226,6 +229,9 @@ static int mchp_tc_count_action_set(struct counter_device *counter,
> case MCHP_TC_SYNAPSE_ACTION_BOTH_EDGE:
> edge = ATMEL_TC_ETRGEDG_BOTH;
> break;
> + default:
> + /* should never reach this path */
> + return -EINVAL;
> }
>
> return regmap_write_bits(priv->regmap,
> diff --git a/drivers/counter/stm32-lptimer-cnt.c b/drivers/counter/stm32-lptimer-cnt.c
> index c19d998df5ba..78f383b77bd2 100644
> --- a/drivers/counter/stm32-lptimer-cnt.c
> +++ b/drivers/counter/stm32-lptimer-cnt.c
> @@ -206,9 +206,10 @@ static int stm32_lptim_cnt_function_set(struct counter_device *counter,
> priv->quadrature_mode = 1;
> priv->polarity = STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES;
> return 0;
> + default:
> + /* should never reach this path */
> + return -EINVAL;
> }
> -
> - return -EINVAL;
> }
>
> static ssize_t stm32_lptim_cnt_enable_read(struct counter_device *counter,
> @@ -326,9 +327,10 @@ static int stm32_lptim_cnt_action_get(struct counter_device *counter,
> case STM32_LPTIM_ENCODER_BOTH_EDGE:
> *action = priv->polarity;
> return 0;
> + default:
> + /* should never reach this path */
> + return -EINVAL;
> }
> -
> - return -EINVAL;
> }
>
> static int stm32_lptim_cnt_action_set(struct counter_device *counter,
> diff --git a/drivers/counter/ti-eqep.c b/drivers/counter/ti-eqep.c
> index 65df9ef5b5bc..c303eb17c111 100644
> --- a/drivers/counter/ti-eqep.c
> +++ b/drivers/counter/ti-eqep.c
> @@ -157,7 +157,7 @@ static int ti_eqep_action_get(struct counter_device *counter,
> * QEPA and QEPB trigger QCLK.
> */
> *action = TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES;
> - break;
> + return 0;
> case TI_EQEP_COUNT_FUNC_DIR_COUNT:
> /* In direction-count mode only rising edge of QEPA is counted
> * and QEPB gives direction.
> @@ -165,12 +165,14 @@ static int ti_eqep_action_get(struct counter_device *counter,
> switch (synapse->signal->id) {
> case TI_EQEP_SIGNAL_QEPA:
> *action = TI_EQEP_SYNAPSE_ACTION_RISING_EDGE;
> - break;
> - default:
> + return 0;
> + case TI_EQEP_SIGNAL_QEPB:
> *action = TI_EQEP_SYNAPSE_ACTION_NONE;
> - break;
> + return 0;
> + default:
> + /* should never reach this path */
> + return -EINVAL;
> }
> - break;
> case TI_EQEP_COUNT_FUNC_UP_COUNT:
> case TI_EQEP_COUNT_FUNC_DOWN_COUNT:
> /* In up/down-count modes only QEPA is counted and QEPB is not
> @@ -186,15 +188,18 @@ static int ti_eqep_action_get(struct counter_device *counter,
> *action = TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES;
> else
> *action = TI_EQEP_SYNAPSE_ACTION_RISING_EDGE;
> - break;
> - default:
> + return 0;
> + case TI_EQEP_SIGNAL_QEPB:
> *action = TI_EQEP_SYNAPSE_ACTION_NONE;
> - break;
> + return 0;
> + default:
> + /* should never reach this path */
> + return -EINVAL;
> }
> - break;
> + default:
> + /* should never reach this path */
> + return -EINVAL;
> }
> -
> - return 0;
> }
>
> static const struct counter_ops ti_eqep_counter_ops = {
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