Fix W=1 warning. The kernel doc uses the hwparams type instead of the argument name. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Link: https://lore.kernel.org/r/20200702193842.169215-1-pierre-louis.bossart@linux.intel.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
		
			
				
	
	
		
			124 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			124 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-only
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| /*
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|  *  PCM DRM helpers
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|  */
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| #include <linux/export.h>
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| #include <linux/types.h>
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| #include <sound/asoundef.h>
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| #include <sound/pcm.h>
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| #include <sound/pcm_params.h>
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| #include <sound/pcm_iec958.h>
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| 
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| static int create_iec958_consumer(uint rate, uint sample_width,
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| 				  u8 *cs, size_t len)
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| {
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| 	unsigned int fs, ws;
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| 
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| 	if (len < 4)
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| 		return -EINVAL;
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| 
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| 	switch (rate) {
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| 	case 32000:
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| 		fs = IEC958_AES3_CON_FS_32000;
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| 		break;
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| 	case 44100:
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| 		fs = IEC958_AES3_CON_FS_44100;
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| 		break;
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| 	case 48000:
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| 		fs = IEC958_AES3_CON_FS_48000;
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| 		break;
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| 	case 88200:
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| 		fs = IEC958_AES3_CON_FS_88200;
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| 		break;
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| 	case 96000:
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| 		fs = IEC958_AES3_CON_FS_96000;
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| 		break;
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| 	case 176400:
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| 		fs = IEC958_AES3_CON_FS_176400;
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| 		break;
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| 	case 192000:
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| 		fs = IEC958_AES3_CON_FS_192000;
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| 		break;
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| 	default:
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| 		return -EINVAL;
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| 	}
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| 
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| 	if (len > 4) {
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| 		switch (sample_width) {
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| 		case 16:
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| 			ws = IEC958_AES4_CON_WORDLEN_20_16;
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| 			break;
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| 		case 18:
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| 			ws = IEC958_AES4_CON_WORDLEN_22_18;
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| 			break;
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| 		case 20:
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| 			ws = IEC958_AES4_CON_WORDLEN_20_16 |
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| 			     IEC958_AES4_CON_MAX_WORDLEN_24;
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| 			break;
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| 		case 24:
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| 		case 32: /* Assume 24-bit width for 32-bit samples. */
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| 			ws = IEC958_AES4_CON_WORDLEN_24_20 |
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| 			     IEC958_AES4_CON_MAX_WORDLEN_24;
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| 			break;
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| 
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| 		default:
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| 			return -EINVAL;
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| 		}
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| 	}
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| 
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| 	memset(cs, 0, len);
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| 
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| 	cs[0] = IEC958_AES0_CON_NOT_COPYRIGHT | IEC958_AES0_CON_EMPHASIS_NONE;
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| 	cs[1] = IEC958_AES1_CON_GENERAL;
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| 	cs[2] = IEC958_AES2_CON_SOURCE_UNSPEC | IEC958_AES2_CON_CHANNEL_UNSPEC;
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| 	cs[3] = IEC958_AES3_CON_CLOCK_1000PPM | fs;
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| 
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| 	if (len > 4)
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| 		cs[4] = ws;
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| 
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| 	return len;
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| }
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| 
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| /**
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|  * snd_pcm_create_iec958_consumer - create consumer format IEC958 channel status
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|  * @runtime: pcm runtime structure with ->rate filled in
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|  * @cs: channel status buffer, at least four bytes
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|  * @len: length of channel status buffer
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|  *
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|  * Create the consumer format channel status data in @cs of maximum size
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|  * @len corresponding to the parameters of the PCM runtime @runtime.
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|  *
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|  * Drivers may wish to tweak the contents of the buffer after creation.
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|  *
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|  * Returns: length of buffer, or negative error code if something failed.
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|  */
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| int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
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| 	size_t len)
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| {
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| 	return create_iec958_consumer(runtime->rate,
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| 				      snd_pcm_format_width(runtime->format),
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| 				      cs, len);
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| }
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| EXPORT_SYMBOL(snd_pcm_create_iec958_consumer);
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| 
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| /**
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|  * snd_pcm_create_iec958_consumer_hw_params - create IEC958 channel status
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|  * @params: the hw_params instance for extracting rate and sample format
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|  * @cs: channel status buffer, at least four bytes
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|  * @len: length of channel status buffer
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|  *
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|  * Create the consumer format channel status data in @cs of maximum size
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|  * @len corresponding to the parameters of the PCM runtime @runtime.
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|  *
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|  * Drivers may wish to tweak the contents of the buffer after creation.
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|  *
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|  * Returns: length of buffer, or negative error code if something failed.
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|  */
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| int snd_pcm_create_iec958_consumer_hw_params(struct snd_pcm_hw_params *params,
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| 					     u8 *cs, size_t len)
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| {
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| 	return create_iec958_consumer(params_rate(params), params_width(params),
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| 				      cs, len);
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| }
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| EXPORT_SYMBOL(snd_pcm_create_iec958_consumer_hw_params);
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