ASoC: mxs-saif: add record function

1. add different clkmux mode handling
SAIF can use two instances to implement full duplex (playback &
recording) and record saif may work on EXTMASTER mode which is
using other saif's BITCLK&LRCLK.

The clkmux mode could be set in pdata->init() in mach-specific code.
For generic saif driver, it only needs to know who is his master
and the master id is also provided in mach-specific code.

2. support playback and capture simutaneously however the sample
rates can not be different due to hw limitation.

Signed-off-by: Dong Aisheng <b29396@freescale.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

2 files changed, 135 insertions, 14 deletions

diff --git a/sound/soc/mxs/mxs-saif.c b/sound/soc/mxs/mxs-saif.c
index af5734f6dab7..401944cf4560 100644
--- a/sound/soc/mxs/mxs-saif.c
+++ b/sound/soc/mxs/mxs-saif.c
@@ -23,10 +23,12 @@
 #include <linux/dma-mapping.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/time.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
+#include <sound/saif.h>
 #include <mach/dma.h>
 #include <asm/mach-types.h>
 #include <mach/hardware.h>
@@ -36,6 +38,24 @@
 
 static struct mxs_saif *mxs_saif[2];
 
+/*
+ * SAIF is a little different with other normal SOC DAIs on clock using.
+ *
+ * For MXS, two SAIF modules are instantiated on-chip.
+ * Each SAIF has a set of clock pins and can be operating in master
+ * mode simultaneously if they are connected to different off-chip codecs.
+ * Also, one of the two SAIFs can master or drive the clock pins while the
+ * other SAIF, in slave mode, receives clocking from the master SAIF.
+ * This also means that both SAIFs must operate at the same sample rate.
+ *
+ * We abstract this as each saif has a master, the master could be
+ * himself or other saifs. In the generic saif driver, saif does not need
+ * to know the different clkmux. Saif only needs to know who is his master
+ * and operating his master to generate the proper clock rate for him.
+ * The master id is provided in mach-specific layer according to different
+ * clkmux setting.
+ */
+
 static int mxs_saif_set_dai_sysclk(struct snd_soc_dai *cpu_dai,
                         int clk_id, unsigned int freq, int dir)
 {
@@ -52,6 +72,17 @@ static int mxs_saif_set_dai_sysclk(struct snd_soc_dai *cpu_dai,
 }
 
 /*
+ * Since SAIF may work on EXTMASTER mode, IOW, it's working BITCLK&LRCLK
+ * is provided by other SAIF, we provide a interface here to get its master
+ * from its master_id.
+ * Note that the master could be himself.
+ */
+static inline struct mxs_saif *mxs_saif_get_master(struct mxs_saif * saif)
+{
+        return mxs_saif[saif->master_id];
+}
+
+/*
  * Set SAIF clock and MCLK
  */
 static int mxs_saif_set_clk(struct mxs_saif *saif,
@@ -60,8 +91,26 @@ static int mxs_saif_set_clk(struct mxs_saif *saif,
 {
         u32 scr;
         int ret;
+        struct mxs_saif *master_saif;
 
-        scr = __raw_readl(saif->base + SAIF_CTRL);
+        dev_dbg(saif->dev, "mclk %d rate %d\n", mclk, rate);
+
+        /* Set master saif to generate proper clock */
+        master_saif = mxs_saif_get_master(saif);
+        if (!master_saif)
+                return -EINVAL;
+
+        dev_dbg(saif->dev, "master saif%d\n", master_saif->id);
+
+        /* Checking if can playback and capture simutaneously */
+        if (master_saif->ongoing && rate != master_saif->cur_rate) {
+                dev_err(saif->dev,
+                        "can not change clock, master saif%d(rate %d) is ongoing\n",
+                        master_saif->id, master_saif->cur_rate);
+                return -EINVAL;
+        }
+
+        scr = __raw_readl(master_saif->base + SAIF_CTRL);
         scr &= ~BM_SAIF_CTRL_BITCLK_MULT_RATE;
         scr &= ~BM_SAIF_CTRL_BITCLK_BASE_RATE;
 
@@ -75,27 +124,29 @@ static int mxs_saif_set_clk(struct mxs_saif *saif,
          *
          * If MCLK is not used, we just set saif clk to 512*fs.
          */
-        if (saif->mclk_in_use) {
+        if (master_saif->mclk_in_use) {
                 if (mclk % 32 == 0) {
                         scr &= ~BM_SAIF_CTRL_BITCLK_BASE_RATE;
-                        ret = clk_set_rate(saif->clk, 512 * rate);
+                        ret = clk_set_rate(master_saif->clk, 512 * rate);
                 } else if (mclk % 48 == 0) {
                         scr |= BM_SAIF_CTRL_BITCLK_BASE_RATE;
-                        ret = clk_set_rate(saif->clk, 384 * rate);
+                        ret = clk_set_rate(master_saif->clk, 384 * rate);
                 } else {
                         /* SAIF MCLK should be either 32x or 48x */
                         return -EINVAL;
                 }
         } else {
-                ret = clk_set_rate(saif->clk, 512 * rate);
+                ret = clk_set_rate(master_saif->clk, 512 * rate);
                 scr &= ~BM_SAIF_CTRL_BITCLK_BASE_RATE;
         }
 
         if (ret)
                 return ret;
 
-        if (!saif->mclk_in_use) {
-                __raw_writel(scr, saif->base + SAIF_CTRL);
+        master_saif->cur_rate = rate;
+
+        if (!master_saif->mclk_in_use) {
+                __raw_writel(scr, master_saif->base + SAIF_CTRL);
                 return 0;
         }
 
@@ -137,7 +188,7 @@ static int mxs_saif_set_clk(struct mxs_saif *saif,
                 return -EINVAL;
         }
 
-        __raw_writel(scr, saif->base + SAIF_CTRL);
+        __raw_writel(scr, master_saif->base + SAIF_CTRL);
 
         return 0;
 }
@@ -183,6 +234,7 @@ int mxs_saif_get_mclk(unsigned int saif_id, unsigned int mclk,
         struct mxs_saif *saif = mxs_saif[saif_id];
         u32 stat;
         int ret;
+        struct mxs_saif *master_saif;
 
         if (!saif)
                 return -EINVAL;
@@ -195,6 +247,12 @@ int mxs_saif_get_mclk(unsigned int saif_id, unsigned int mclk,
         __raw_writel(BM_SAIF_CTRL_CLKGATE,
                 saif->base + SAIF_CTRL + MXS_CLR_ADDR);
 
+        master_saif = mxs_saif_get_master(saif);
+        if (saif != master_saif) {
+                dev_err(saif->dev, "can not get mclk from a non-master saif\n");
+                return -EINVAL;
+        }
+
         stat = __raw_readl(saif->base + SAIF_STAT);
         if (stat & BM_SAIF_STAT_BUSY) {
                 dev_err(saif->dev, "error: busy\n");
@@ -278,10 +336,17 @@ static int mxs_saif_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
         /*
          * Note: We simply just support master mode since SAIF TX can only
          * work as master.
+         * Here the master is relative to codec side.
+         * Saif internally could be slave when working on EXTMASTER mode.
+         * We just hide this to machine driver.
          */
         switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
         case SND_SOC_DAIFMT_CBS_CFS:
-                scr &= ~BM_SAIF_CTRL_SLAVE_MODE;
+                if (saif->id == saif->master_id)
+                        scr &= ~BM_SAIF_CTRL_SLAVE_MODE;
+                else
+                        scr |= BM_SAIF_CTRL_SLAVE_MODE;
+
                 __raw_writel(scr | scr0, saif->base + SAIF_CTRL);
                 break;
         default:
@@ -396,6 +461,12 @@ static int mxs_saif_trigger(struct snd_pcm_substream *substream, int cmd,
                                 struct snd_soc_dai *cpu_dai)
 {
         struct mxs_saif *saif = snd_soc_dai_get_drvdata(cpu_dai);
+        struct mxs_saif *master_saif;
+        u32 delay;
+
+        master_saif = mxs_saif_get_master(saif);
+        if (!master_saif)
+                return -EINVAL;
 
         switch (cmd) {
         case SNDRV_PCM_TRIGGER_START:
@@ -403,10 +474,20 @@ static int mxs_saif_trigger(struct snd_pcm_substream *substream, int cmd,
         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                 dev_dbg(cpu_dai->dev, "start\n");
 
-                clk_enable(saif->clk);
-                if (!saif->mclk_in_use)
+                clk_enable(master_saif->clk);
+                if (!master_saif->mclk_in_use)
+                        __raw_writel(BM_SAIF_CTRL_RUN,
+                                master_saif->base + SAIF_CTRL + MXS_SET_ADDR);
+
+                /*
+                 * If the saif's master is not himself, we also need to enable
+                 * itself clk for its internal basic logic to work.
+                 */
+                if (saif != master_saif) {
+                        clk_enable(saif->clk);
                         __raw_writel(BM_SAIF_CTRL_RUN,
                                 saif->base + SAIF_CTRL + MXS_SET_ADDR);
+                }
 
                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                         /*
@@ -422,20 +503,39 @@ static int mxs_saif_trigger(struct snd_pcm_substream *substream, int cmd,
                         __raw_readl(saif->base + SAIF_DATA);
                 }
 
-                dev_dbg(cpu_dai->dev, "CTRL 0x%x STAT 0x%x\n",
+                master_saif->ongoing = 1;
+
+                dev_dbg(saif->dev, "CTRL 0x%x STAT 0x%x\n",
                         __raw_readl(saif->base + SAIF_CTRL),
                         __raw_readl(saif->base + SAIF_STAT));
 
+                dev_dbg(master_saif->dev, "CTRL 0x%x STAT 0x%x\n",
+                        __raw_readl(master_saif->base + SAIF_CTRL),
+                        __raw_readl(master_saif->base + SAIF_STAT));
                 break;
         case SNDRV_PCM_TRIGGER_SUSPEND:
         case SNDRV_PCM_TRIGGER_STOP:
         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                 dev_dbg(cpu_dai->dev, "stop\n");
 
-                clk_disable(saif->clk);
-                if (!saif->mclk_in_use)
+                /* wait a while for the current sample to complete */
+                delay = USEC_PER_SEC / master_saif->cur_rate;
+
+                if (!master_saif->mclk_in_use) {
+                        __raw_writel(BM_SAIF_CTRL_RUN,
+                                master_saif->base + SAIF_CTRL + MXS_CLR_ADDR);
+                        udelay(delay);
+                }
+                clk_disable(master_saif->clk);
+
+                if (saif != master_saif) {
                         __raw_writel(BM_SAIF_CTRL_RUN,
                                 saif->base + SAIF_CTRL + MXS_CLR_ADDR);
+                        udelay(delay);
+                        clk_disable(saif->clk);
+                }
+
+                master_saif->ongoing = 0;
 
                 break;
         default:
@@ -519,16 +619,33 @@ static int mxs_saif_probe(struct platform_device *pdev)
 {
         struct resource *res;
         struct mxs_saif *saif;
+        struct mxs_saif_platform_data *pdata;
         int ret = 0;
 
         if (pdev->id >= ARRAY_SIZE(mxs_saif))
                 return -EINVAL;
 
+        pdata = pdev->dev.platform_data;
+        if (pdata && pdata->init) {
+                ret = pdata->init();
+                if (ret)
+                        return ret;
+        }
+
         saif = kzalloc(sizeof(*saif), GFP_KERNEL);
         if (!saif)
                 return -ENOMEM;
 
         mxs_saif[pdev->id] = saif;
+        saif->id = pdev->id;
+
+        saif->master_id = saif->id;
+        if (pdata && pdata->get_master_id) {
+                saif->master_id = pdata->get_master_id(saif->id);
+                if (saif->master_id < 0 ||
+                        saif->master_id >= ARRAY_SIZE(mxs_saif))
+                        return -EINVAL;
+        }
 
         saif->clk = clk_get(&pdev->dev, NULL);
         if (IS_ERR(saif->clk)) {
diff --git a/sound/soc/mxs/mxs-saif.h b/sound/soc/mxs/mxs-saif.h
index 0e2ff8cdbfee..12c91e4eb941 100644
--- a/sound/soc/mxs/mxs-saif.h
+++ b/sound/soc/mxs/mxs-saif.h
@@ -118,6 +118,10 @@ struct mxs_saif {
         void __iomem *base;
         int irq;
         struct mxs_pcm_dma_params dma_param;
+        unsigned int id;
+        unsigned int master_id;
+        unsigned int cur_rate;
+        unsigned int ongoing;
 
         struct platform_device *soc_platform_pdev;
         u32 fifo_underrun;