summaryrefslogtreecommitdiff
path: root/sound/soc/cirrus/ep93xx-i2s.c
diff options
context:
space:
mode:
Diffstat (limited to 'sound/soc/cirrus/ep93xx-i2s.c')
-rw-r--r--sound/soc/cirrus/ep93xx-i2s.c106
1 files changed, 86 insertions, 20 deletions
diff --git a/sound/soc/cirrus/ep93xx-i2s.c b/sound/soc/cirrus/ep93xx-i2s.c
index 934f8aefdd90..0918c5da575a 100644
--- a/sound/soc/cirrus/ep93xx-i2s.c
+++ b/sound/soc/cirrus/ep93xx-i2s.c
@@ -35,8 +35,12 @@
#define EP93XX_I2S_TXCLKCFG 0x00
#define EP93XX_I2S_RXCLKCFG 0x04
+#define EP93XX_I2S_GLSTS 0x08
#define EP93XX_I2S_GLCTRL 0x0C
+#define EP93XX_I2S_I2STX0LFT 0x10
+#define EP93XX_I2S_I2STX0RT 0x14
+
#define EP93XX_I2S_TXLINCTRLDATA 0x28
#define EP93XX_I2S_TXCTRL 0x2C
#define EP93XX_I2S_TXWRDLEN 0x30
@@ -51,7 +55,17 @@
#define EP93XX_I2S_WRDLEN_24 (1 << 0)
#define EP93XX_I2S_WRDLEN_32 (2 << 0)
-#define EP93XX_I2S_LINCTRLDATA_R_JUST (1 << 2) /* Right justify */
+#define EP93XX_I2S_RXLINCTRLDATA_R_JUST BIT(1) /* Right justify */
+
+#define EP93XX_I2S_TXLINCTRLDATA_R_JUST BIT(2) /* Right justify */
+
+/*
+ * Transmit empty interrupt level select:
+ * 0 - Generate interrupt when FIFO is half empty
+ * 1 - Generate interrupt when FIFO is empty
+ */
+#define EP93XX_I2S_TXCTRL_TXEMPTY_LVL BIT(0)
+#define EP93XX_I2S_TXCTRL_TXUFIE BIT(1) /* Transmit interrupt enable */
#define EP93XX_I2S_CLKCFG_LRS (1 << 0) /* lrclk polarity */
#define EP93XX_I2S_CLKCFG_CKP (1 << 1) /* Bit clock polarity */
@@ -59,6 +73,8 @@
#define EP93XX_I2S_CLKCFG_MASTER (1 << 3) /* Master mode */
#define EP93XX_I2S_CLKCFG_NBCG (1 << 4) /* Not bit clock gating */
+#define EP93XX_I2S_GLSTS_TX0_FIFO_FULL BIT(12)
+
struct ep93xx_i2s_info {
struct clk *mclk;
struct clk *sclk;
@@ -96,7 +112,6 @@ static inline unsigned ep93xx_i2s_read_reg(struct ep93xx_i2s_info *info,
static void ep93xx_i2s_enable(struct ep93xx_i2s_info *info, int stream)
{
unsigned base_reg;
- int i;
if ((ep93xx_i2s_read_reg(info, EP93XX_I2S_TX0EN) & 0x1) == 0 &&
(ep93xx_i2s_read_reg(info, EP93XX_I2S_RX0EN) & 0x1) == 0) {
@@ -109,27 +124,36 @@ static void ep93xx_i2s_enable(struct ep93xx_i2s_info *info, int stream)
ep93xx_i2s_write_reg(info, EP93XX_I2S_GLCTRL, 1);
}
- /* Enable fifos */
+ /* Enable fifo */
if (stream == SNDRV_PCM_STREAM_PLAYBACK)
base_reg = EP93XX_I2S_TX0EN;
else
base_reg = EP93XX_I2S_RX0EN;
- for (i = 0; i < 3; i++)
- ep93xx_i2s_write_reg(info, base_reg + (i * 4), 1);
+ ep93xx_i2s_write_reg(info, base_reg, 1);
+
+ /* Enable TX IRQs (FIFO empty or underflow) */
+ if (IS_ENABLED(CONFIG_SND_EP93XX_SOC_I2S_WATCHDOG) &&
+ stream == SNDRV_PCM_STREAM_PLAYBACK)
+ ep93xx_i2s_write_reg(info, EP93XX_I2S_TXCTRL,
+ EP93XX_I2S_TXCTRL_TXEMPTY_LVL |
+ EP93XX_I2S_TXCTRL_TXUFIE);
}
static void ep93xx_i2s_disable(struct ep93xx_i2s_info *info, int stream)
{
unsigned base_reg;
- int i;
- /* Disable fifos */
+ /* Disable IRQs */
+ if (IS_ENABLED(CONFIG_SND_EP93XX_SOC_I2S_WATCHDOG) &&
+ stream == SNDRV_PCM_STREAM_PLAYBACK)
+ ep93xx_i2s_write_reg(info, EP93XX_I2S_TXCTRL, 0);
+
+ /* Disable fifo */
if (stream == SNDRV_PCM_STREAM_PLAYBACK)
base_reg = EP93XX_I2S_TX0EN;
else
base_reg = EP93XX_I2S_RX0EN;
- for (i = 0; i < 3; i++)
- ep93xx_i2s_write_reg(info, base_reg + (i * 4), 0);
+ ep93xx_i2s_write_reg(info, base_reg, 0);
if ((ep93xx_i2s_read_reg(info, EP93XX_I2S_TX0EN) & 0x1) == 0 &&
(ep93xx_i2s_read_reg(info, EP93XX_I2S_RX0EN) & 0x1) == 0) {
@@ -143,6 +167,37 @@ static void ep93xx_i2s_disable(struct ep93xx_i2s_info *info, int stream)
}
}
+/*
+ * According to documentation I2S controller can handle underflow conditions
+ * just fine, but in reality the state machine is sometimes confused so that
+ * the whole stream is shifted by one byte. The watchdog below disables the TX
+ * FIFO, fills the buffer with zeroes and re-enables the FIFO. State machine
+ * is being reset and by filling the buffer we get some time before next
+ * underflow happens.
+ */
+static irqreturn_t ep93xx_i2s_interrupt(int irq, void *dev_id)
+{
+ struct ep93xx_i2s_info *info = dev_id;
+
+ /* Disable FIFO */
+ ep93xx_i2s_write_reg(info, EP93XX_I2S_TX0EN, 0);
+ /*
+ * Fill TX FIFO with zeroes, this way we can defer next IRQs as much as
+ * possible and get more time for DMA to catch up. Actually there are
+ * only 8 samples in this FIFO, so even on 8kHz maximum deferral here is
+ * 1ms.
+ */
+ while (!(ep93xx_i2s_read_reg(info, EP93XX_I2S_GLSTS) &
+ EP93XX_I2S_GLSTS_TX0_FIFO_FULL)) {
+ ep93xx_i2s_write_reg(info, EP93XX_I2S_I2STX0LFT, 0);
+ ep93xx_i2s_write_reg(info, EP93XX_I2S_I2STX0RT, 0);
+ }
+ /* Re-enable FIFO */
+ ep93xx_i2s_write_reg(info, EP93XX_I2S_TX0EN, 1);
+
+ return IRQ_HANDLED;
+}
+
static int ep93xx_i2s_dai_probe(struct snd_soc_dai *dai)
{
struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(dai);
@@ -170,25 +225,25 @@ static int ep93xx_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
unsigned int fmt)
{
struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(cpu_dai);
- unsigned int clk_cfg, lin_ctrl;
+ unsigned int clk_cfg;
+ unsigned int txlin_ctrl = 0;
+ unsigned int rxlin_ctrl = 0;
clk_cfg = ep93xx_i2s_read_reg(info, EP93XX_I2S_RXCLKCFG);
- lin_ctrl = ep93xx_i2s_read_reg(info, EP93XX_I2S_RXLINCTRLDATA);
switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
case SND_SOC_DAIFMT_I2S:
clk_cfg |= EP93XX_I2S_CLKCFG_REL;
- lin_ctrl &= ~EP93XX_I2S_LINCTRLDATA_R_JUST;
break;
case SND_SOC_DAIFMT_LEFT_J:
clk_cfg &= ~EP93XX_I2S_CLKCFG_REL;
- lin_ctrl &= ~EP93XX_I2S_LINCTRLDATA_R_JUST;
break;
case SND_SOC_DAIFMT_RIGHT_J:
clk_cfg &= ~EP93XX_I2S_CLKCFG_REL;
- lin_ctrl |= EP93XX_I2S_LINCTRLDATA_R_JUST;
+ rxlin_ctrl |= EP93XX_I2S_RXLINCTRLDATA_R_JUST;
+ txlin_ctrl |= EP93XX_I2S_TXLINCTRLDATA_R_JUST;
break;
default:
@@ -213,32 +268,32 @@ static int ep93xx_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
case SND_SOC_DAIFMT_NB_NF:
/* Negative bit clock, lrclk low on left word */
- clk_cfg &= ~(EP93XX_I2S_CLKCFG_CKP | EP93XX_I2S_CLKCFG_REL);
+ clk_cfg &= ~(EP93XX_I2S_CLKCFG_CKP | EP93XX_I2S_CLKCFG_LRS);
break;
case SND_SOC_DAIFMT_NB_IF:
/* Negative bit clock, lrclk low on right word */
clk_cfg &= ~EP93XX_I2S_CLKCFG_CKP;
- clk_cfg |= EP93XX_I2S_CLKCFG_REL;
+ clk_cfg |= EP93XX_I2S_CLKCFG_LRS;
break;
case SND_SOC_DAIFMT_IB_NF:
/* Positive bit clock, lrclk low on left word */
clk_cfg |= EP93XX_I2S_CLKCFG_CKP;
- clk_cfg &= ~EP93XX_I2S_CLKCFG_REL;
+ clk_cfg &= ~EP93XX_I2S_CLKCFG_LRS;
break;
case SND_SOC_DAIFMT_IB_IF:
/* Positive bit clock, lrclk low on right word */
- clk_cfg |= EP93XX_I2S_CLKCFG_CKP | EP93XX_I2S_CLKCFG_REL;
+ clk_cfg |= EP93XX_I2S_CLKCFG_CKP | EP93XX_I2S_CLKCFG_LRS;
break;
}
/* Write new register values */
ep93xx_i2s_write_reg(info, EP93XX_I2S_RXCLKCFG, clk_cfg);
ep93xx_i2s_write_reg(info, EP93XX_I2S_TXCLKCFG, clk_cfg);
- ep93xx_i2s_write_reg(info, EP93XX_I2S_RXLINCTRLDATA, lin_ctrl);
- ep93xx_i2s_write_reg(info, EP93XX_I2S_TXLINCTRLDATA, lin_ctrl);
+ ep93xx_i2s_write_reg(info, EP93XX_I2S_RXLINCTRLDATA, rxlin_ctrl);
+ ep93xx_i2s_write_reg(info, EP93XX_I2S_TXLINCTRLDATA, txlin_ctrl);
return 0;
}
@@ -392,6 +447,17 @@ static int ep93xx_i2s_probe(struct platform_device *pdev)
if (IS_ERR(info->regs))
return PTR_ERR(info->regs);
+ if (IS_ENABLED(CONFIG_SND_EP93XX_SOC_I2S_WATCHDOG)) {
+ int irq = platform_get_irq(pdev, 0);
+ if (irq <= 0)
+ return irq < 0 ? irq : -ENODEV;
+
+ err = devm_request_irq(&pdev->dev, irq, ep93xx_i2s_interrupt, 0,
+ pdev->name, info);
+ if (err)
+ return err;
+ }
+
info->mclk = clk_get(&pdev->dev, "mclk");
if (IS_ERR(info->mclk)) {
err = PTR_ERR(info->mclk);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-18 14:50:46 +0000