On Mon, Apr 15, 2013 at 12:32 PM, Ben Wu <crayben@xxxxxxxx> wrote:
Dear All ，Im new to linux kernel program, and found struct pointer is difficult to understand, that the struct s3c_i2sv2_info *i2s = snd_soc_dai_get_drvdata(cpu_dai) means,? why is use the struct pointer assgn another struct pointer??
static int s3c2412_i2s_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params,
struct snd_soc_dai *cpu_dai)
{
struct s3c_i2sv2_info *i2s = snd_soc_dai_get_drvdata(cpu_dai);
struct s3c_dma_params *dma_data;
....................................................................
}
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Have a look at a utility binary "cdecl". This will help you greatly. However, the statement above means, snd_soc... is a function which takes a argument which is a pointer and returns a pointer to struct s3c_.. Here the pointer i2s is declared and initialize. Else it will do nasty thing if you try to de-reference it. |
Thanks,
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