ALSA: snd-atmel-ac97c: enable interrupts to catch events for error reporting

This patch will enable interrupts from AC97C and report about error
conditions that occurs.

On channel A both overrun and underrun will be enabled depending if
playback and/or capture are enabled. On the control channel the overrun
interrupt is enabled.

Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 76 insertions, 1 deletions

diff --git a/sound/atmel/ac97c.c b/sound/atmel/ac97c.c
index c9bc3458fa2d..e8484cb9ac62 100644
--- a/sound/atmel/ac97c.c
+++ b/sound/atmel/ac97c.c
@@ -66,6 +66,7 @@ struct atmel_ac97c {
         /* Serialize access to opened variable */
         spinlock_t                      lock;
         void __iomem                    *regs;
+        int                             irq;
         int                             opened;
         int                             reset_pin;
 };
@@ -335,8 +336,16 @@ static int atmel_ac97c_playback_prepare(struct snd_pcm_substream *substream)
                 return -EINVAL;
         }
 
+        /* Enable underrun interrupt on channel A */
+        word |= AC97C_CSR_UNRUN;
+
         ac97c_writel(chip, CAMR, word);
 
+        /* Enable channel A event interrupt */
+        word = ac97c_readl(chip, IMR);
+        word |= AC97C_SR_CAEVT;
+        ac97c_writel(chip, IER, word);
+
         /* set variable rate if needed */
         if (runtime->rate != 48000) {
                 word = ac97c_readl(chip, MR);
@@ -402,8 +411,16 @@ static int atmel_ac97c_capture_prepare(struct snd_pcm_substream *substream)
                 return -EINVAL;
         }
 
+        /* Enable overrun interrupt on channel A */
+        word |= AC97C_CSR_OVRUN;
+
         ac97c_writel(chip, CAMR, word);
 
+        /* Enable channel A event interrupt */
+        word = ac97c_readl(chip, IMR);
+        word |= AC97C_SR_CAEVT;
+        ac97c_writel(chip, IER, word);
+
         /* set variable rate if needed */
         if (runtime->rate != 48000) {
                 word = ac97c_readl(chip, MR);
@@ -554,6 +571,43 @@ static struct snd_pcm_ops atmel_ac97_capture_ops = {
         .pointer        = atmel_ac97c_capture_pointer,
 };
 
+static irqreturn_t atmel_ac97c_interrupt(int irq, void *dev)
+{
+        struct atmel_ac97c      *chip  = (struct atmel_ac97c *)dev;
+        irqreturn_t             retval = IRQ_NONE;
+        u32                     sr     = ac97c_readl(chip, SR);
+        u32                     casr   = ac97c_readl(chip, CASR);
+        u32                     cosr   = ac97c_readl(chip, COSR);
+
+        if (sr & AC97C_SR_CAEVT) {
+                dev_info(&chip->pdev->dev, "channel A event%s%s%s%s%s%s\n",
+                                casr & AC97C_CSR_OVRUN   ? " OVRUN"   : "",
+                                casr & AC97C_CSR_RXRDY   ? " RXRDY"   : "",
+                                casr & AC97C_CSR_UNRUN   ? " UNRUN"   : "",
+                                casr & AC97C_CSR_TXEMPTY ? " TXEMPTY" : "",
+                                casr & AC97C_CSR_TXRDY   ? " TXRDY"   : "",
+                                !casr                    ? " NONE"    : "");
+                retval = IRQ_HANDLED;
+        }
+
+        if (sr & AC97C_SR_COEVT) {
+                dev_info(&chip->pdev->dev, "codec channel event%s%s%s%s%s\n",
+                                cosr & AC97C_CSR_OVRUN   ? " OVRUN"   : "",
+                                cosr & AC97C_CSR_RXRDY   ? " RXRDY"   : "",
+                                cosr & AC97C_CSR_TXEMPTY ? " TXEMPTY" : "",
+                                cosr & AC97C_CSR_TXRDY   ? " TXRDY"   : "",
+                                !cosr                    ? " NONE"    : "");
+                retval = IRQ_HANDLED;
+        }
+
+        if (retval == IRQ_NONE) {
+                dev_err(&chip->pdev->dev, "spurious interrupt sr 0x%08x "
+                                "casr 0x%08x cosr 0x%08x\n", sr, casr, cosr);
+        }
+
+        return retval;
+}
+
 static int __devinit atmel_ac97c_pcm_new(struct atmel_ac97c *chip)
 {
         struct snd_pcm          *pcm;
@@ -701,6 +755,7 @@ static int __devinit atmel_ac97c_probe(struct platform_device *pdev)
                 .read   = atmel_ac97c_read,
         };
         int                             retval;
+        int                             irq;
 
         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
         if (!regs) {
@@ -714,6 +769,12 @@ static int __devinit atmel_ac97c_probe(struct platform_device *pdev)
                 return -ENXIO;
         }
 
+        irq = platform_get_irq(pdev, 0);
+        if (irq < 0) {
+                dev_dbg(&pdev->dev, "could not get irq\n");
+                return -ENXIO;
+        }
+
         pclk = clk_get(&pdev->dev, "pclk");
         if (IS_ERR(pclk)) {
                 dev_dbg(&pdev->dev, "no peripheral clock\n");
@@ -730,6 +791,13 @@ static int __devinit atmel_ac97c_probe(struct platform_device *pdev)
 
         chip = get_chip(card);
 
+        retval = request_irq(irq, atmel_ac97c_interrupt, 0, "AC97C", chip);
+        if (retval) {
+                dev_dbg(&pdev->dev, "unable to request irq %d\n", irq);
+                goto err_request_irq;
+        }
+        chip->irq = irq;
+
         spin_lock_init(&chip->lock);
 
         strcpy(card->driver, "Atmel AC97C");
@@ -758,6 +826,10 @@ static int __devinit atmel_ac97c_probe(struct platform_device *pdev)
 
         snd_card_set_dev(card, &pdev->dev);
 
+        /* Enable overrun interrupt from codec channel */
+        ac97c_writel(chip, COMR, AC97C_CSR_OVRUN);
+        ac97c_writel(chip, IER, ac97c_readl(chip, IMR) | AC97C_SR_COEVT);
+
         retval = snd_ac97_bus(card, 0, &ops, chip, &chip->ac97_bus);
         if (retval) {
                 dev_dbg(&pdev->dev, "could not register on ac97 bus\n");
@@ -820,7 +892,7 @@ static int __devinit atmel_ac97c_probe(struct platform_device *pdev)
         retval = snd_card_register(card);
         if (retval) {
                 dev_dbg(&pdev->dev, "could not register sound card\n");
-                goto err_ac97_bus;
+                goto err_dma;
         }
 
         platform_set_drvdata(pdev, card);
@@ -847,6 +919,8 @@ err_ac97_bus:
 
         iounmap(chip->regs);
 err_ioremap:
+        free_irq(irq, chip);
+err_request_irq:
         snd_card_free(card);
 err_snd_card_new:
         clk_disable(pclk);
@@ -898,6 +972,7 @@ static int __devexit atmel_ac97c_remove(struct platform_device *pdev)
         clk_disable(chip->pclk);
         clk_put(chip->pclk);
         iounmap(chip->regs);
+        free_irq(chip->irq, chip);
 
         if (test_bit(DMA_RX_CHAN_PRESENT, &chip->flags))
                 dma_release_channel(chip->dma.rx_chan);