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-rw-r--r--drivers/counter/stm32-timer-cnt.c55
1 files changed, 33 insertions, 22 deletions
diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
index ef2a974a2f10..75bc401fdd18 100644
--- a/drivers/counter/stm32-timer-cnt.c
+++ b/drivers/counter/stm32-timer-cnt.c
@@ -31,7 +31,7 @@ struct stm32_timer_cnt {
struct counter_device counter;
struct regmap *regmap;
struct clk *clk;
- u32 ceiling;
+ u32 max_arr;
bool enabled;
struct stm32_timer_regs bak;
};
@@ -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,
@@ -73,8 +74,10 @@ static int stm32_count_write(struct counter_device *counter,
const unsigned long val)
{
struct stm32_timer_cnt *const priv = counter->priv;
+ u32 ceiling;
- if (val > priv->ceiling)
+ regmap_read(priv->regmap, TIM_ARR, &ceiling);
+ if (val > ceiling)
return -EINVAL;
return regmap_write(priv->regmap, TIM_CNT, val);
@@ -90,6 +93,9 @@ 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 +105,9 @@ 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 +118,9 @@ 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 +131,7 @@ static int stm32_count_function_set(struct counter_device *counter,
sms = 3;
break;
default:
- sms = 0;
- break;
+ return -EINVAL;
}
/* Store enable status */
@@ -131,10 +139,6 @@ static int stm32_count_function_set(struct counter_device *counter,
regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
- /* TIMx_ARR register shouldn't be buffered (ARPE=0) */
- regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
- regmap_write(priv->regmap, TIM_ARR, priv->ceiling);
-
regmap_update_bits(priv->regmap, TIM_SMCR, TIM_SMCR_SMS, sms);
/* Make sure that registers are updated */
@@ -185,11 +189,13 @@ static ssize_t stm32_count_ceiling_write(struct counter_device *counter,
if (ret)
return ret;
+ if (ceiling > priv->max_arr)
+ return -ERANGE;
+
/* TIMx_ARR register shouldn't be buffered (ARPE=0) */
regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
regmap_write(priv->regmap, TIM_ARR, ceiling);
- priv->ceiling = ceiling;
return len;
}
@@ -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 = {
@@ -359,7 +370,7 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev)
priv->regmap = ddata->regmap;
priv->clk = ddata->clk;
- priv->ceiling = ddata->max_arr;
+ priv->max_arr = ddata->max_arr;
priv->counter.name = dev_name(dev);
priv->counter.parent = dev;