[ALSA] CS4270 driver does not compile with I2C disabled

Fix compilation errors with the CS4270 when I2C is not enabled.  Updated
some comments to indicate that that stand-alone mode is not fully implemented,
because there is no mechanism for the CS4270 driver and the machine driver to
communicate the values of various input pins.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 172 insertions, 147 deletions

diff --git a/sound/soc/codecs/cs4270.c b/sound/soc/codecs/cs4270.c
index b659a5dfd77..8beae65d083 100644
--- a/sound/soc/codecs/cs4270.c
+++ b/sound/soc/codecs/cs4270.c
@@ -12,9 +12,11 @@
  *
  * Current features/limitations:
  *
- * 1) Stand-alone and software mode is supported.  Stand-alone is
- *    automatically selected if I2C is disabled or if a CS4270 is not found
- *    on the I2C bus.
+ * 1) Software mode is supported.  Stand-alone mode is automatically
+ *    selected if I2C is disabled or if a CS4270 is not found on the I2C
+ *    bus.  However, stand-alone mode is only partially implemented because
+ *    there is no mechanism yet for this driver and the machine driver to
+ *    communicate the values of the M0, M1, MCLK1, and MCLK2 pins.
  * 2) Only I2C is supported, not SPI
  * 3) Only Master mode is supported, not Slave.
  * 4) The machine driver's 'startup' function must call
@@ -34,12 +36,157 @@
 
 #include "cs4270.h"
 
+/* If I2C is defined, then we support software mode.  However, if we're
+   not compiled as module but I2C is, then we can't use I2C calls. */
+#if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
+#define USE_I2C
+#endif
+
 /* Private data for the CS4270 */
 struct cs4270_private {
         unsigned int mclk; /* Input frequency of the MCLK pin */
         unsigned int mode; /* The mode (I2S or left-justified) */
 };
 
+/* The number of MCLK/LRCK ratios supported by the CS4270 */
+#define NUM_MCLK_RATIOS         9
+
+/* The actual MCLK/LRCK ratios, in increasing numerical order */
+static unsigned int mclk_ratios[NUM_MCLK_RATIOS] =
+        {64, 96, 128, 192, 256, 384, 512, 768, 1024};
+
+/*
+ * Sampling rate <-> bit patter mapping
+ *
+ * This array maps sampling rates to their SNDRV_PCM_RATE_x equivalent.
+ *
+ * This is really something that ALSA should provide.
+ *
+ * This table is used by cs4270_set_dai_sysclk() to tell ALSA which sampling
+ * rates the CS4270 currently supports.
+ */
+static struct {
+        unsigned int rate;
+        unsigned int bit;
+} rate_map[] = {
+        {5512, SNDRV_PCM_RATE_5512},
+        {8000, SNDRV_PCM_RATE_8000},
+        {11025, SNDRV_PCM_RATE_11025},
+        {16000, SNDRV_PCM_RATE_16000},
+        {22050, SNDRV_PCM_RATE_22050},
+        {32000, SNDRV_PCM_RATE_32000},
+        {44100, SNDRV_PCM_RATE_44100},
+        {48000, SNDRV_PCM_RATE_48000},
+        {64000, SNDRV_PCM_RATE_64000},
+        {88200, SNDRV_PCM_RATE_88200},
+        {96000, SNDRV_PCM_RATE_96000},
+        {176400, SNDRV_PCM_RATE_176400},
+        {192000, SNDRV_PCM_RATE_192000}
+};
+
+/*
+ * Determine the CS4270 samples rates.
+ *
+ * 'freq' is the input frequency to MCLK.  The other parameters are ignored.
+ *
+ * The value of MCLK is used to determine which sample rates are supported
+ * by the CS4270.  The ratio of MCLK / Fs must be equal to one of nine
+ * support values: 64, 96, 128, 192, 256, 384, 512, 768, and 1024.
+ *
+ * This function calculates the nine ratios and determines which ones match
+ * a standard sample rate.  If there's a match, then it is added to the list
+ * of support sample rates.
+ *
+ * This function must be called by the machine driver's 'startup' function,
+ * otherwise the list of supported sample rates will not be available in
+ * time for ALSA.
+ *
+ * Note that in stand-alone mode, the sample rate is determined by input
+ * pins M0, M1, MDIV1, and MDIV2.  Also in stand-alone mode, divide-by-3
+ * is not a programmable option.  However, divide-by-3 is not an available
+ * option in stand-alone mode.  This cases two problems: a ratio of 768 is
+ * not available (it requires divide-by-3) and B) ratios 192 and 384 can
+ * only be selected with divide-by-1.5, but there is an errate that make
+ * this selection difficult.
+ *
+ * In addition, there is no mechanism for communicating with the machine
+ * driver what the input settings can be.  This would need to be implemented
+ * for stand-alone mode to work.
+ */
+static int cs4270_set_dai_sysclk(struct snd_soc_codec_dai *codec_dai,
+                                 int clk_id, unsigned int freq, int dir)
+{
+        struct snd_soc_codec *codec = codec_dai->codec;
+        struct cs4270_private *cs4270 = codec->private_data;
+        unsigned int rates = 0;
+        unsigned int rate_min = -1;
+        unsigned int rate_max = 0;
+        unsigned int i;
+
+        cs4270->mclk = freq;
+
+        for (i = 0; i < NUM_MCLK_RATIOS; i++) {
+                unsigned int rate;
+                unsigned int j;
+                rate = freq / mclk_ratios[i];
+                for (j = 0; j < ARRAY_SIZE(rate_map); j++) {
+                        if (rate == rate_map[j].rate) {
+                                rates |= rate_map[j].bit;
+                                if (rate < rate_min)
+                                        rate_min = rate;
+                                if (rate > rate_max)
+                                        rate_max = rate;
+                        }
+                }
+        }
+
+        if (!rates) {
+                printk(KERN_ERR "cs4270: could not find a valid sample rate\n");
+                return -EINVAL;
+        }
+
+        codec_dai->playback.rates = rates;
+        codec_dai->playback.rate_min = rate_min;
+        codec_dai->playback.rate_max = rate_max;
+
+        codec_dai->capture.rates = rates;
+        codec_dai->capture.rate_min = rate_min;
+        codec_dai->capture.rate_max = rate_max;
+
+        return 0;
+}
+
+/*
+ * Configure the codec for the selected audio format
+ *
+ * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the
+ * codec accordingly.
+ *
+ * Currently, this function only supports SND_SOC_DAIFMT_I2S and
+ * SND_SOC_DAIFMT_LEFT_J.  The CS4270 codec also supports right-justified
+ * data for playback only, but ASoC currently does not support different
+ * formats for playback vs. record.
+ */
+static int cs4270_set_dai_fmt(struct snd_soc_codec_dai *codec_dai,
+                              unsigned int format)
+{
+        struct snd_soc_codec *codec = codec_dai->codec;
+        struct cs4270_private *cs4270 = codec->private_data;
+        int ret = 0;
+
+        switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
+        case SND_SOC_DAIFMT_I2S:
+        case SND_SOC_DAIFMT_LEFT_J:
+                cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK;
+                break;
+        default:
+                printk(KERN_ERR "cs4270: invalid DAI format\n");
+                ret = -EINVAL;
+        }
+
+        return ret;
+}
+
 /*
  * The codec isn't really big-endian or little-endian, since the I2S
  * interface requires data to be sent serially with the MSbit first.
@@ -53,7 +200,7 @@ struct cs4270_private {
                         SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | \
                         SNDRV_PCM_FMTBIT_S24_LE  | SNDRV_PCM_FMTBIT_S24_BE)
 
-#ifdef CONFIG_I2C
+#ifdef USE_I2C
 
 /* CS4270 registers addresses */
 #define CS4270_CHIPID   0x01    /* Chip ID */
@@ -141,7 +288,7 @@ static int cs4270_fill_cache(struct snd_soc_codec *codec)
                 CS4270_FIRSTREG | 0x80, CS4270_NUMREGS, cache);
 
         if (length != CS4270_NUMREGS) {
-                printk(KERN_ERR "cs4270: I2C read failure, addr=%u\n",
+                printk(KERN_ERR "cs4270: I2C read failure, addr=0x%x\n",
                        i2c_client->addr);
                 return -EIO;
         }
@@ -189,13 +336,14 @@ static int cs4270_i2c_write(struct snd_soc_codec *codec, unsigned int reg,
                 cache[reg - CS4270_FIRSTREG] = value;
                 return 0;
         } else {
-                printk(KERN_ERR "cs4270: I2C write failed\n");
+                printk(KERN_ERR "cs4270: I2C write of register %u failed\n",
+                        reg);
                 return -EIO;
         }
 }
 
 /*
- * Clock Ratio Selection for Master Mode.
+ * Clock Ratio Selection for Master Mode with I2C enabled
  *
  * The data for this chart is taken from Table 5 of the CS4270 reference
  * manual.
@@ -204,10 +352,8 @@ static int cs4270_i2c_write(struct snd_soc_codec *codec, unsigned int reg,
  * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling
  * rates the CS4270 currently supports.
  *
- * 'ratio' is the MCLK/LRCK ratio.  MCLK is usually a fixed input frequency,
- * and LRCK is equal to the sampling rate. The CS4270 only supports sampling
- * rates where this ratio is one of: 64, 96, 128, 192, 256, 384, 512, 768 or
- * 1024.
+ * Each element in this array corresponds to the ratios in mclk_ratios[].
+ * These two arrays need to be in sync.
  *
  * 'speed_mode' is the corresponding bit pattern to be written to the
  * MODE bits of the Mode Control Register
@@ -227,21 +373,20 @@ static int cs4270_i2c_write(struct snd_soc_codec *codec, unsigned int reg,
  * never select any sample rates that require divide-by-1.5.
  */
 static struct {
-        unsigned int ratio;
         u8 speed_mode;
         u8 mclk;
-} cs4270_mode_ratios[] = {
-        {64, CS4270_MODE_4X, CS4270_MODE_DIV1},
+} cs4270_mode_ratios[NUM_MCLK_RATIOS] = {
+        {CS4270_MODE_4X, CS4270_MODE_DIV1},     /* 64 */
 #ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA
-        {96, CS4270_MODE_4X, CS4270_MODE_DIV15},
+        {CS4270_MODE_4X, CS4270_MODE_DIV15},    /* 96 */
 #endif
-        {128, CS4270_MODE_2X, CS4270_MODE_DIV1},
-        {192, CS4270_MODE_4X, CS4270_MODE_DIV3},
-        {256, CS4270_MODE_1X, CS4270_MODE_DIV1},
-        {384, CS4270_MODE_2X, CS4270_MODE_DIV3},
-        {512, CS4270_MODE_1X, CS4270_MODE_DIV2},
-        {768, CS4270_MODE_1X, CS4270_MODE_DIV3},
-        {1024, CS4270_MODE_1X, CS4270_MODE_DIV4}
+        {CS4270_MODE_2X, CS4270_MODE_DIV1},     /* 128 */
+        {CS4270_MODE_4X, CS4270_MODE_DIV3},     /* 192 */
+        {CS4270_MODE_1X, CS4270_MODE_DIV1},     /* 256 */
+        {CS4270_MODE_2X, CS4270_MODE_DIV3},     /* 384 */
+        {CS4270_MODE_1X, CS4270_MODE_DIV2},     /* 512 */
+        {CS4270_MODE_1X, CS4270_MODE_DIV3},     /* 768 */
+        {CS4270_MODE_1X, CS4270_MODE_DIV4}      /* 1024 */
 };
 
 /*
@@ -270,12 +415,12 @@ static int cs4270_hw_params(struct snd_pcm_substream *substream,
         rate = params_rate(params);     /* Sampling rate, in Hz */
         ratio = cs4270->mclk / rate;    /* MCLK/LRCK ratio */
 
-        for (i = 0; i < ARRAY_SIZE(cs4270_mode_ratios); i++) {
-                if (cs4270_mode_ratios[i].ratio == ratio)
+        for (i = 0; i < NUM_MCLK_RATIOS; i++) {
+                if (mclk_ratios[i] == ratio)
                         break;
         }
 
-        if (i == ARRAY_SIZE(cs4270_mode_ratios)) {
+        if (i == NUM_MCLK_RATIOS) {
                 /* We did not find a matching ratio */
                 printk(KERN_ERR "cs4270: could not find matching ratio\n");
                 return -EINVAL;
@@ -377,126 +522,6 @@ static int cs4270_mute(struct snd_soc_codec_dai *dai, int mute)
 
 #endif
 
-/*
- * Sampling rate <-> bit patter mapping
- *
- * This array maps sampling rates to their SNDRV_PCM_RATE_x equivalent.
- *
- * This is really something that ALSA should provide.
- *
- * This table is used by cs4270_set_dai_sysclk() to tell ALSA which sampling
- * rates the CS4270 currently supports.
- */
-static struct {
-        unsigned int rate;
-        unsigned int bit;
-} rate_map[] = {
-        {5512, SNDRV_PCM_RATE_5512},
-        {8000, SNDRV_PCM_RATE_8000},
-        {11025, SNDRV_PCM_RATE_11025},
-        {16000, SNDRV_PCM_RATE_16000},
-        {22050, SNDRV_PCM_RATE_22050},
-        {32000, SNDRV_PCM_RATE_32000},
-        {44100, SNDRV_PCM_RATE_44100},
-        {48000, SNDRV_PCM_RATE_48000},
-        {64000, SNDRV_PCM_RATE_64000},
-        {88200, SNDRV_PCM_RATE_88200},
-        {96000, SNDRV_PCM_RATE_96000},
-        {176400, SNDRV_PCM_RATE_176400},
-        {192000, SNDRV_PCM_RATE_192000}
-};
-
-/*
- * Determine the CS4270 samples rates.
- *
- * 'freq' is the input frequency to MCLK.  The other parameters are ignored.
- *
- * The value of MCLK is used to determine which sample rates are supported
- * by the CS4270.  The ratio of MCLK / Fs must be equal to one of nine
- * support values: 64, 96, 128, 192, 256, 384, 512, 768, and 1024.
- *
- * This function calculates the nine ratios and determines which ones match
- * a standard sample rate.  If there's a match, then it is added to the list
- * of support sample rates.
- *
- * This function must be called by the machine driver's 'startup' function,
- * otherwise the list of supported sample rates will not be available in
- * time for ALSA.
- */
-static int cs4270_set_dai_sysclk(struct snd_soc_codec_dai *codec_dai,
-                                 int clk_id, unsigned int freq, int dir)
-{
-        struct snd_soc_codec *codec = codec_dai->codec;
-        struct cs4270_private *cs4270 = codec->private_data;
-        unsigned int rates = 0;
-        unsigned int rate_min = -1;
-        unsigned int rate_max = 0;
-        unsigned int i;
-
-        cs4270->mclk = freq;
-
-        for (i = 0; i < ARRAY_SIZE(cs4270_mode_ratios); i++) {
-                unsigned int rate;
-                unsigned int j;
-                rate = freq / cs4270_mode_ratios[i].ratio;
-                for (j = 0; j < ARRAY_SIZE(rate_map); j++) {
-                        if (rate == rate_map[j].rate) {
-                                rates |= rate_map[j].bit;
-                                if (rate < rate_min)
-                                        rate_min = rate;
-                                if (rate > rate_max)
-                                        rate_max = rate;
-                        }
-                }
-        }
-
-        if (!rate_max) {
-                printk(KERN_ERR "cs4270: could not find a valid rate\n");
-                return -EINVAL;
-        }
-
-        codec_dai->playback.rates = rates;
-        codec_dai->playback.rate_min = rate_min;
-        codec_dai->playback.rate_max = rate_max;
-
-        codec_dai->capture.rates = rates;
-        codec_dai->capture.rate_min = rate_min;
-        codec_dai->capture.rate_max = rate_max;
-
-        return 0;
-}
-
-/*
- * Configure the codec for the selected audio format
- *
- * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the
- * codec accordingly.
- *
- * Currently, this function only supports SND_SOC_DAIFMT_I2S and
- * SND_SOC_DAIFMT_LEFT_J.  The CS4270 codec also supports right-justified
- * data for playback only, but ASoC currently does not support different
- * formats for playback vs. record.
- */
-static int cs4270_set_dai_fmt(struct snd_soc_codec_dai *codec_dai,
-                              unsigned int format)
-{
-        struct snd_soc_codec *codec = codec_dai->codec;
-        struct cs4270_private *cs4270 = codec->private_data;
-        int ret = 0;
-
-        switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
-        case SND_SOC_DAIFMT_I2S:
-        case SND_SOC_DAIFMT_LEFT_J:
-                cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK;
-                break;
-        default:
-                printk(KERN_ERR "cs4270: invalid DAI format\n");
-                ret = -EINVAL;
-        }
-
-        return ret;
-}
-
 static int cs4270_i2c_probe(struct i2c_adapter *adap, int addr, int kind);
 
 /*
@@ -740,7 +765,7 @@ static int cs4270_probe(struct platform_device *pdev)
                 return ret;
         }
 
-#ifdef CONFIG_I2C
+#ifdef USE_I2C
         cs4270_socdev = socdev;
 
         ret = i2c_add_driver(&cs4270_i2c_driver);
@@ -780,7 +805,7 @@ static int cs4270_remove(struct platform_device *pdev)
 
         snd_soc_free_pcms(socdev);
 
-#ifdef CONFIG_I2C
+#ifdef USE_I2C
         if (socdev->codec->control_data)
                 i2c_del_driver(&cs4270_i2c_driver);
 #endif