[alsa-devel] [PATCH v4 01/19] ALSA: Oxygen: Add the separate SPI waiting function

[Roman Volkov]

The oxygen_wait_spi() function now performs waiting when the
SPI bus completes a transaction. Introduce the timeout error
checking and increase timeout to 200 from 40.

Signed-off-by: Roman Volkov <v1ron at mail.ru>
---
 sound/pci/oxygen/oxygen_io.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/sound/pci/oxygen/oxygen_io.c b/sound/pci/oxygen/oxygen_io.c
index 521eae4..471e64a 100644
--- a/sound/pci/oxygen/oxygen_io.c
+++ b/sound/pci/oxygen/oxygen_io.c
@@ -194,6 +194,21 @@ void oxygen_write_ac97_masked(struct oxygen *chip, unsigned int codec,
 }
 EXPORT_SYMBOL(oxygen_write_ac97_masked);
 
+static int oxygen_wait_spi(struct oxygen *chip)
+{
+	/* Higher timeout to be sure: 200 us,
+	   Actual transaction should not need more than 40 us */
+	unsigned int count;
+	for (count = 50; count > 0; count--) {
+		udelay(4);
+		if ((oxygen_read8(chip, OXYGEN_SPI_CONTROL) &
+						OXYGEN_SPI_BUSY) == 0)
+			return 0;
+	}
+	snd_printk(KERN_ERR "Oxygen: SPI wait timeout\n");
+	return -EIO;
+}
+
 void oxygen_write_spi(struct oxygen *chip, u8 control, unsigned int data)
 {
 	unsigned int count;
-- 
1.7.10.4