staging: most: add multi channel support to sound AIM

This patch adds 5.1 surround configuration with subbuffer cross-check,
when establishing a link to the core. For the sake of simplicity, only
one specific channel configuration is allowed.

Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/most/aim-sound/sound.c b/drivers/staging/most/aim-sound/sound.c
index 0d7425b19f1ea978c67edb07f797831b5d9fed6e..88221f03032527a1f713a96a279449f9a04f1355 100644 (file)
--- a/drivers/staging/most/aim-sound/sound.c
+++ b/drivers/staging/most/aim-sound/sound.c
@@ -19,6 +19,7 @@
 #include <linux/init.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
+#include <sound/pcm_params.h>
 #include <linux/sched.h>
 #include <linux/kthread.h>
 #include <mostcore.h>
@@ -75,7 +76,7 @@ static struct snd_pcm_hardware pcm_hardware_template = {
        .rate_min           = 48000,
        .rate_max           = 48000,
        .channels_min       = 1,
-       .channels_max       = 8,
+       .channels_max       = 1,
 };
 
 #define swap16(val) ( \
@@ -355,10 +356,18 @@ static int pcm_close(struct snd_pcm_substream *substream)
 static int pcm_hw_params(struct snd_pcm_substream *substream,
                         struct snd_pcm_hw_params *hw_params)
 {
+       int ret;
+
        pr_info("pcm_hw_params()\n");
 
-       return snd_pcm_lib_alloc_vmalloc_buffer(substream,
+       if ((params_channels(hw_params) > pcm_hardware_template.channels_max) ||
+           (params_channels(hw_params) < pcm_hardware_template.channels_min) ||
+           !(params_format(hw_params) != pcm_hardware_template.formats))
+               return -EINVAL;
+       ret = snd_pcm_lib_alloc_vmalloc_buffer(substream,
                                                params_buffer_bytes(hw_params));
+
+       return ret;
 }
 
 /**
@@ -511,20 +520,34 @@ static int audio_set_pcm_format(char *pcm_format,
                if (cfg->subbuffer_size != 4)
                        goto error;
                pr_info("PCM format is 16-bit stereo\n");
+               pcm_hardware_template.channels_min = 2;
+               pcm_hardware_template.channels_max = 2;
                pcm_hardware_template.formats = SNDRV_PCM_FMTBIT_S16_LE |
                                                SNDRV_PCM_FMTBIT_S16_BE;
        } else if (!strcmp(pcm_format, "2x24")) {
                if (cfg->subbuffer_size != 6)
                        goto error;
                pr_info("PCM format is 24-bit stereo\n");
+               pcm_hardware_template.channels_min = 2;
+               pcm_hardware_template.channels_max = 2;
                pcm_hardware_template.formats = SNDRV_PCM_FMTBIT_S24_3LE |
                                                SNDRV_PCM_FMTBIT_S24_3BE;
        } else if (!strcmp(pcm_format, "2x32")) {
                if (cfg->subbuffer_size != 8)
                        goto error;
                pr_info("PCM format is 32-bit stereo\n");
+               pcm_hardware_template.channels_min = 2;
+               pcm_hardware_template.channels_max = 2;
                pcm_hardware_template.formats = SNDRV_PCM_FMTBIT_S32_LE |
                                                SNDRV_PCM_FMTBIT_S32_BE;
+       } else if (!strcmp(pcm_format, "6x16")) {
+               if (cfg->subbuffer_size != 12)
+                       goto error;
+               pr_info("PCM format is 16-bit 5.1 multi channel\n");
+               pcm_hardware_template.channels_min = 6;
+               pcm_hardware_template.channels_max = 6;
+               pcm_hardware_template.formats = SNDRV_PCM_FMTBIT_S16_LE |
+                                               SNDRV_PCM_FMTBIT_S16_BE;
        } else {
                pr_err("PCM format %s not supported\n", pcm_format);
                return -EIO;