Merge tag 'mute-led-rework' of https://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound into asoc-5.13

ALSA: control - add generic LED API

This patchset tries to resolve the diversity in the audio LED
control among the ALSA drivers. A new control layer registration
is introduced which allows to run additional operations on
top of the elementary ALSA sound controls.

A new control access group (three bits in the access flags)
was introduced to carry the LED group information for
the sound controls. The low-level sound drivers can just
mark those controls using this access group. This information
is not exported to the user space, but user space can
manage the LED sound control associations through sysfs
(last patch) per Mark's request. It makes things fully
configurable in the kernel and user space (UCM).

The actual state ('route') evaluation is really easy
(the minimal value check for all channels / controls / cards).
If there's more complicated logic for a given hardware,
the card driver may eventually export a new read-only
sound control for the LED group and do the logic itself.

The new LED trigger control code is completely separated
and possibly optional (there's no symbol dependency).
The full code separation allows eventually to move this
LED trigger control to the user space in future.
Actually it replaces the already present functionality
in the kernel space (HDA drivers) and allows a quick adoption
for the recent hardware (ASoC codecs including SoundWire).

snd_ctl_led            24576  0

The sound driver implementation is really easy:

1) call snd_ctl_led_request() when control LED layer should be
   automatically activated
   / it calls module_request("snd-ctl-led") on demand /
2) mark all related kcontrols with
        SNDRV_CTL_ELEM_ACCESS_SPK_LED or
        SNDRV_CTL_ELEM_ACCESS_MIC_LED

Link: https://lore.kernel.org/r/20210317172945.842280-1-perex@perex.cz
Signed-off-by: Takashi Iwai <tiwai@suse.de>

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;