This patch improves fsl_sai_isr() in these ways:
1, Add comment for mask fetching code.
2, Return IRQ_NONE if the IRQ is not for the device.
3, Use regmap_write() instead of regmap_update_bits().
Signed-off-by: Nicolin Chen <guangyu.c...@freescale.com>
---
sound/soc/fsl/fsl_sai.c | 64 ++++++++++++++++++++++++++++++++++---------------
1 file changed, 45 insertions(+), 19 deletions(-)
diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index 0bc98bb..f088545 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -30,62 +30,88 @@ static irqreturn_t fsl_sai_isr(int irq, void *devid)
{
struct fsl_sai *sai = (struct fsl_sai *)devid;
struct device *dev = &sai->pdev->dev;
- u32 xcsr, mask;
+ u32 flags, xcsr, mask;
+ bool irq_none = true;
- /* Only handle those what we enabled */
+ /*
+ * Both IRQ status bits and IRQ mask bits are in the xCSR but
+ * different shifts. And we here create a mask only for those
+ * IRQs that we activated.
+ */
mask = (FSL_SAI_FLAGS >> FSL_SAI_CSR_xIE_SHIFT) << FSL_SAI_CSR_xF_SHIFT;
/* Tx IRQ */
regmap_read(sai->regmap, FSL_SAI_TCSR, &xcsr);
- xcsr &= mask;
+ flags = xcsr & mask;
- if (xcsr & FSL_SAI_CSR_WSF)
+ if (flags)
+ irq_none = false;
+ else
+ goto irq_rx;
+
+ if (flags & FSL_SAI_CSR_WSF)
dev_dbg(dev, "isr: Start of Tx word detected\n");
- if (xcsr & FSL_SAI_CSR_SEF)
+ if (flags & FSL_SAI_CSR_SEF)
dev_warn(dev, "isr: Tx Frame sync error detected\n");
- if (xcsr & FSL_SAI_CSR_FEF) {
+ if (flags & FSL_SAI_CSR_FEF) {
dev_warn(dev, "isr: Transmit underrun detected\n");
/* FIFO reset for safety */
xcsr |= FSL_SAI_CSR_FR;
}
- if (xcsr & FSL_SAI_CSR_FWF)
+ if (flags & FSL_SAI_CSR_FWF)
dev_dbg(dev, "isr: Enabled transmit FIFO is empty\n");
- if (xcsr & FSL_SAI_CSR_FRF)
+ if (flags & FSL_SAI_CSR_FRF)
dev_dbg(dev, "isr: Transmit FIFO watermark has been reached\n");
- regmap_update_bits(sai->regmap, FSL_SAI_TCSR,
- FSL_SAI_CSR_xF_W_MASK | FSL_SAI_CSR_FR, xcsr);
+ flags &= FSL_SAI_CSR_xF_W_MASK;
+ xcsr &= ~FSL_SAI_CSR_xF_MASK;
+
+ if (flags)
+ regmap_write(sai->regmap, FSL_SAI_TCSR, flags | xcsr);
+irq_rx:
/* Rx IRQ */
regmap_read(sai->regmap, FSL_SAI_RCSR, &xcsr);
- xcsr &= mask;
+ flags = xcsr & mask;
- if (xcsr & FSL_SAI_CSR_WSF)
+ if (flags)
+ irq_none = false;
+ else
+ goto out;
+
+ if (flags & FSL_SAI_CSR_WSF)
dev_dbg(dev, "isr: Start of Rx word detected\n");
- if (xcsr & FSL_SAI_CSR_SEF)
+ if (flags & FSL_SAI_CSR_SEF)
dev_warn(dev, "isr: Rx Frame sync error detected\n");
- if (xcsr & FSL_SAI_CSR_FEF) {
+ if (flags & FSL_SAI_CSR_FEF) {
dev_warn(dev, "isr: Receive overflow detected\n");
/* FIFO reset for safety */
xcsr |= FSL_SAI_CSR_FR;
}
- if (xcsr & FSL_SAI_CSR_FWF)
+ if (flags & FSL_SAI_CSR_FWF)
dev_dbg(dev, "isr: Enabled receive FIFO is full\n");
- if (xcsr & FSL_SAI_CSR_FRF)
+ if (flags & FSL_SAI_CSR_FRF)
dev_dbg(dev, "isr: Receive FIFO watermark has been reached\n");
- regmap_update_bits(sai->regmap, FSL_SAI_RCSR,
- FSL_SAI_CSR_xF_W_MASK | FSL_SAI_CSR_FR, xcsr);
+ flags &= FSL_SAI_CSR_xF_W_MASK;
+ xcsr &= ~FSL_SAI_CSR_xF_MASK;
- return IRQ_HANDLED;
+ if (flags)
+ regmap_write(sai->regmap, FSL_SAI_TCSR, flags | xcsr);
+
+out:
+ if (irq_none)
+ return IRQ_NONE;
+ else
+ return IRQ_HANDLED;
}
static int fsl_sai_set_dai_sysclk_tr(struct snd_soc_dai *cpu_dai,
--
1.8.4
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