Merge tag 'counter-fixes-6.3a' of git://git.kernel.org/pub/scm/linux/kernel/git/wbg/counter into char-misc-linus

William writes:

First set of Counter driver fixes for 6.3

This set consists of two fixes for the 104-quad-8 driver:
	- fix a read race condition between the FLAG and CNTR registers
	  (as a result 25-bit count values are no longer supported)
	- invert condition check to report correct Index Synapse action

* tag 'counter-fixes-6.3a' of git://git.kernel.org/pub/scm/linux/kernel/git/wbg/counter:
  counter: 104-quad-8: Fix Synapse action reported for Index signals
  counter: 104-quad-8: Fix race condition between FLAG and CNTR reads

1 files changed, 9 insertions, 22 deletions

diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c
index deed4afadb29..d9cb937665cf 100644
--- a/drivers/counter/104-quad-8.c
+++ b/drivers/counter/104-quad-8.c
@@ -97,10 +97,6 @@ struct quad8 {
 	struct quad8_reg __iomem *reg;
 };
 
-/* Borrow Toggle flip-flop */
-#define QUAD8_FLAG_BT BIT(0)
-/* Carry Toggle flip-flop */
-#define QUAD8_FLAG_CT BIT(1)
 /* Error flag */
 #define QUAD8_FLAG_E BIT(4)
 /* Up/Down flag */
@@ -133,6 +129,9 @@ struct quad8 {
 #define QUAD8_CMR_QUADRATURE_X2 0x10
 #define QUAD8_CMR_QUADRATURE_X4 0x18
 
+/* Each Counter is 24 bits wide */
+#define LS7267_CNTR_MAX GENMASK(23, 0)
+
 static int quad8_signal_read(struct counter_device *counter,
 			     struct counter_signal *signal,
 			     enum counter_signal_level *level)
@@ -156,18 +155,10 @@ static int quad8_count_read(struct counter_device *counter,
 {
 	struct quad8 *const priv = counter_priv(counter);
 	struct channel_reg __iomem *const chan = priv->reg->channel + count->id;
-	unsigned int flags;
-	unsigned int borrow;
-	unsigned int carry;
 	unsigned long irqflags;
 	int i;
 
-	flags = ioread8(&chan->control);
-	borrow = flags & QUAD8_FLAG_BT;
-	carry = !!(flags & QUAD8_FLAG_CT);
-
-	/* Borrow XOR Carry effectively doubles count range */
-	*val = (unsigned long)(borrow ^ carry) << 24;
+	*val = 0;
 
 	spin_lock_irqsave(&priv->lock, irqflags);
 
@@ -191,8 +182,7 @@ static int quad8_count_write(struct counter_device *counter,
 	unsigned long irqflags;
 	int i;
 
-	/* Only 24-bit values are supported */
-	if (val > 0xFFFFFF)
+	if (val > LS7267_CNTR_MAX)
 		return -ERANGE;
 
 	spin_lock_irqsave(&priv->lock, irqflags);
@@ -378,7 +368,7 @@ static int quad8_action_read(struct counter_device *counter,
 
 	/* Handle Index signals */
 	if (synapse->signal->id >= 16) {
-		if (priv->preset_enable[count->id])
+		if (!priv->preset_enable[count->id])
 			*action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
 		else
 			*action = COUNTER_SYNAPSE_ACTION_NONE;
@@ -806,8 +796,7 @@ static int quad8_count_preset_write(struct counter_device *counter,
 	struct quad8 *const priv = counter_priv(counter);
 	unsigned long irqflags;
 
-	/* Only 24-bit values are supported */
-	if (preset > 0xFFFFFF)
+	if (preset > LS7267_CNTR_MAX)
 		return -ERANGE;
 
 	spin_lock_irqsave(&priv->lock, irqflags);
@@ -834,8 +823,7 @@ static int quad8_count_ceiling_read(struct counter_device *counter,
 		*ceiling = priv->preset[count->id];
 		break;
 	default:
-		/* By default 0x1FFFFFF (25 bits unsigned) is maximum count */
-		*ceiling = 0x1FFFFFF;
+		*ceiling = LS7267_CNTR_MAX;
 		break;
 	}
 
@@ -850,8 +838,7 @@ static int quad8_count_ceiling_write(struct counter_device *counter,
 	struct quad8 *const priv = counter_priv(counter);
 	unsigned long irqflags;
 
-	/* Only 24-bit values are supported */
-	if (ceiling > 0xFFFFFF)
+	if (ceiling > LS7267_CNTR_MAX)
 		return -ERANGE;
 
 	spin_lock_irqsave(&priv->lock, irqflags);