V4L/DVB (9651): em28xx: Improve audio handling

This patch properly implements audio handling on em28xx. Before this
patch, it was assumed that every device has an Empia 202 audio chip.
However, this is not true.

After this patch, specific AC97 chipset setup and configurations can be
done.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 205 insertions, 48 deletions

diff --git a/drivers/media/video/em28xx/em28xx-core.c b/drivers/media/video/em28xx/em28xx-core.c
index 4de1b2d433a4..2f3257e87027 100644
--- a/drivers/media/video/em28xx/em28xx-core.c
+++ b/drivers/media/video/em28xx/em28xx-core.c
@@ -224,15 +224,70 @@ static int em28xx_write_reg_bits(struct em28xx *dev, u16 reg, u8 val,
 }
 
 /*
+ * em28xx_is_ac97_ready()
+ * Checks if ac97 is ready
+ */
+static int em28xx_is_ac97_ready(struct em28xx *dev)
+{
+        int ret, i;
+
+        /* Wait up to 50 ms for AC97 command to complete */
+        for (i = 0; i < 10; i++, msleep(5)) {
+                ret = em28xx_read_reg(dev, EM28XX_R43_AC97BUSY);
+                if (ret < 0)
+                        return ret;
+
+                if (!(ret & 0x01))
+                        return 0;
+        }
+
+        em28xx_warn("AC97 command still being executed: not handled properly!\n");
+        return -EBUSY;
+}
+
+/*
+ * em28xx_read_ac97()
+ * write a 16 bit value to the specified AC97 address (LSB first!)
+ */
+static int em28xx_read_ac97(struct em28xx *dev, u8 reg)
+{
+        int ret;
+        u8 addr = (reg & 0x7f) | 0x80;
+        u16 val;
+
+        ret = em28xx_is_ac97_ready(dev);
+        if (ret < 0)
+                return ret;
+
+        ret = em28xx_write_regs(dev, EM28XX_R42_AC97ADDR, &addr, 1);
+        if (ret < 0)
+                return ret;
+
+        ret = dev->em28xx_read_reg_req_len(dev, 0, EM28XX_R40_AC97LSB,
+                                           (u8 *)&val, sizeof(val));
+
+        if (ret < 0)
+                return ret;
+        return le16_to_cpu(val);
+}
+
+/*
  * em28xx_write_ac97()
  * write a 16 bit value to the specified AC97 address (LSB first!)
  */
-static int em28xx_write_ac97(struct em28xx *dev, u8 reg, u8 *val)
+static int em28xx_write_ac97(struct em28xx *dev, u8 reg, u16 val)
 {
-        int ret, i;
+        int ret;
         u8 addr = reg & 0x7f;
+        __le16 value;
+
+        value = cpu_to_le16(val);
+
+        ret = em28xx_is_ac97_ready(dev);
+        if (ret < 0)
+                return ret;
 
-        ret = em28xx_write_regs(dev, EM28XX_R40_AC97LSB, val, 2);
+        ret = em28xx_write_regs(dev, EM28XX_R40_AC97LSB, (u8 *) &value, 2);
         if (ret < 0)
                 return ret;
 
@@ -240,25 +295,36 @@ static int em28xx_write_ac97(struct em28xx *dev, u8 reg, u8 *val)
         if (ret < 0)
                 return ret;
 
-        /* Wait up to 50 ms for AC97 command to complete */
-        for (i = 0; i < 10; i++) {
-                ret = em28xx_read_reg(dev, EM28XX_R43_AC97BUSY);
-                if (ret < 0)
-                        return ret;
+        return 0;
+}
 
-                if (!(ret & 0x01))
-                        return 0;
-                msleep(5);
+static int set_ac97_em202_input(struct em28xx *dev)
+{
+        int ret;
+        u16 enable  = 0x0808;           /* 12 dB attenuation Left/Right */
+        u16 disable = 0x8808;           /* bit 15 - mute volumme */
+        u16 video, line;
+
+        if (dev->ctl_ainput == EM28XX_AMUX_VIDEO) {
+                video = enable;
+                line = disable;
+        } else {
+                video = disable;
+                line  = enable;
         }
-        em28xx_warn("AC97 command still being executed: not handled properly!\n");
-        return 0;
+
+        /* Sets em202 AC97 mixer registers */
+        ret = em28xx_write_ac97(dev, AC97_VIDEO_VOL, video);
+        if (ret < 0)
+                return ret;
+
+        ret = em28xx_write_ac97(dev, AC97_LINEIN_VOL, line);
+
+        return ret;
 }
 
 static int em28xx_set_audio_source(struct em28xx *dev)
 {
-        static char *enable  = "\x08\x08";
-        static char *disable = "\x08\x88";
-        char *video = enable, *line = disable;
         int ret;
         u8 input;
 
@@ -280,18 +346,8 @@ static int em28xx_set_audio_source(struct em28xx *dev)
                 case EM28XX_AMUX_VIDEO:
                         input = EM28XX_AUDIO_SRC_TUNER;
                         break;
-                case EM28XX_AMUX_LINE_IN:
+                default:
                         input = EM28XX_AUDIO_SRC_LINE;
-                        video = disable;
-                        line  = enable;
-                        break;
-                case EM28XX_AMUX_AC97_VIDEO:
-                        input = EM28XX_AUDIO_SRC_LINE;
-                        break;
-                case EM28XX_AMUX_AC97_LINE_IN:
-                        input = EM28XX_AUDIO_SRC_LINE;
-                        video = disable;
-                        line  = enable;
                         break;
                 }
         }
@@ -301,33 +357,36 @@ static int em28xx_set_audio_source(struct em28xx *dev)
                 return ret;
         msleep(5);
 
-        /* Sets AC97 mixer registers
-           This is seems to be needed, even for non-ac97 configs
-         */
-        ret = em28xx_write_ac97(dev, AC97_VIDEO_VOL, video);
-        if (ret < 0)
-                return ret;
-
-        ret = em28xx_write_ac97(dev, AC97_LINEIN_VOL, line);
+        switch (dev->audio_mode.ac97) {
+        case EM28XX_NO_AC97:
+                break;
+        case EM28XX_AC97_OTHER:
+                /* We don't know how to handle this chip.
+                   Let's hope it is close enough to em202 to work
+                 */
+        case EM28XX_AC97_EM202:
+                ret = set_ac97_em202_input(dev);
+                break;
+        }
 
-        return ret;
+        return 0;
 }
 
 int em28xx_audio_analog_set(struct em28xx *dev)
 {
         int ret;
-        char s[2] = { 0x00, 0x00 };
         u8 xclk = 0x07;
 
-        s[0] |= 0x1f - dev->volume;
-        s[1] |= 0x1f - dev->volume;
+        if (!dev->audio_mode.has_audio)
+                return 0;
 
-        /* Mute */
-        s[1] |= 0x80;
-        ret = em28xx_write_ac97(dev, AC97_MASTER_VOL, s);
+        if (dev->audio_mode.ac97 != EM28XX_NO_AC97) {
+                /* Mute */
+                ret = em28xx_write_ac97(dev, AC97_MASTER_VOL, 0x8000);
 
-        if (ret < 0)
-                return ret;
+                if (ret < 0)
+                        return ret;
+        }
 
         if (dev->has_12mhz_i2s)
                 xclk |= 0x20;
@@ -343,15 +402,113 @@ int em28xx_audio_analog_set(struct em28xx *dev)
         /* Selects the proper audio input */
         ret = em28xx_set_audio_source(dev);
 
-        /* Unmute device */
-        if (!dev->mute)
-                s[1] &= ~0x80;
-        ret = em28xx_write_ac97(dev, AC97_MASTER_VOL, s);
+        /* Sets volume */
+        if (dev->audio_mode.ac97 != EM28XX_NO_AC97) {
+                int vol;
+
+                /* LSB: left channel - both channels with the same level */
+                vol = (0x1f - dev->volume) | ((0x1f - dev->volume) << 8);
+
+                /* Mute device, if needed */
+                if (dev->mute)
+                        vol |= 0x8000;
+
+                /* Sets volume */
+                ret = em28xx_write_ac97(dev, AC97_MASTER_VOL, vol);
+        }
 
         return ret;
 }
 EXPORT_SYMBOL_GPL(em28xx_audio_analog_set);
 
+int em28xx_audio_setup(struct em28xx *dev)
+{
+        int vid1, vid2, feat, cfg;
+
+        if (dev->chip_id == CHIP_ID_EM2874) {
+                /* Digital only device - don't load any alsa module */
+                dev->audio_mode.has_audio = 0;
+                dev->has_audio_class = 0;
+                dev->has_alsa_audio = 0;
+                return 0;
+        }
+
+        /* If device doesn't support Usb Audio Class, use vendor class */
+        if (!dev->has_audio_class)
+                dev->has_alsa_audio = 1;
+
+        dev->audio_mode.has_audio = 1;
+
+        /* See how this device is configured */
+        cfg = em28xx_read_reg(dev, EM28XX_R00_CHIPCFG);
+        if (cfg < 0)
+                cfg = EM28XX_CHIPCFG_AC97; /* Be conservative */
+        else
+                em28xx_info("Config register raw data: 0x%02x\n", cfg);
+
+        if ((cfg & EM28XX_CHIPCFG_AUDIOMASK) ==
+                    EM28XX_CHIPCFG_I2S_3_SAMPRATES) {
+                em28xx_info("I2S Audio (3 sample rates)\n");
+                dev->audio_mode.i2s_3rates = 1;
+        }
+        if ((cfg & EM28XX_CHIPCFG_AUDIOMASK) ==
+                    EM28XX_CHIPCFG_I2S_5_SAMPRATES) {
+                em28xx_info("I2S Audio (5 sample rates)\n");
+                dev->audio_mode.i2s_5rates = 1;
+        }
+
+        if (!(cfg & EM28XX_CHIPCFG_AC97)) {
+                dev->audio_mode.ac97 = EM28XX_NO_AC97;
+                goto init_audio;
+        }
+
+        dev->audio_mode.ac97 = EM28XX_AC97_OTHER;
+
+        vid1 = em28xx_read_ac97(dev, AC97_VENDOR_ID1);
+        if (vid1 < 0) {
+                /* Device likely doesn't support AC97 */
+                em28xx_warn("AC97 chip type couldn't be determined\n");
+                goto init_audio;
+        }
+
+        vid2 = em28xx_read_ac97(dev, AC97_VENDOR_ID2);
+        if (vid2 < 0)
+                goto init_audio;
+
+        dev->audio_mode.ac97_vendor_id1 = vid1;
+        dev->audio_mode.ac97_vendor_id2 = vid2;
+        em28xx_warn("AC97 vendor ID = %04x:%04x\n", vid1, vid2);
+
+        feat = em28xx_read_ac97(dev, AC97_RESET);
+        if (feat < 0)
+                goto init_audio;
+
+        dev->audio_mode.ac97_feat = feat;
+        em28xx_warn("AC97 features = 0x%04x\n", feat);
+
+        if ((vid1 == 0xffff) && (vid2 == 0xffff) && (feat == 0x6a90))
+                dev->audio_mode.ac97 = EM28XX_AC97_EM202;
+
+init_audio:
+        /* Reports detected AC97 processor */
+        switch (dev->audio_mode.ac97) {
+        case EM28XX_NO_AC97:
+                em28xx_info("No AC97 audio processor\n");
+                break;
+        case EM28XX_AC97_EM202:
+                em28xx_info("Empia 202 AC97 audio processor detected\n");
+                break;
+        case EM28XX_AC97_OTHER:
+                em28xx_warn("Unknown AC97 audio processor detected!\n");
+                break;
+        default:
+                break;
+        }
+
+        return em28xx_audio_analog_set(dev);
+}
+EXPORT_SYMBOL_GPL(em28xx_audio_setup);
+
 int em28xx_colorlevels_set_default(struct em28xx *dev)
 {
         em28xx_write_regs(dev, EM28XX_R20_YGAIN, "\x10", 1);    /* contrast */