From 065aa40809609ebd94e0296eedb24680d23f5c1b Mon Sep 17 00:00:00 2001 From: Iliyan Malchev Date: Fri, 20 Aug 2010 15:11:48 -0700 Subject: [ARM] tegra: tegra_i2s_audio: allow preloading of the tx fifo with data Add an ioctl to allow the TX fifo to be loaded with data before playback starts. Playback can then be started by calling write() on the FIFO, even with a length of 0. This will cause the pending data to be played out. Signed-off-by: Iliyan Malchev Rebase-Id: Rfcaac1f7a4532ef84c8f5f08db060c256b1d58ac --- arch/arm/mach-tegra/tegra_i2s_audio.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'arch/arm/mach-tegra/tegra_i2s_audio.c') diff --git a/arch/arm/mach-tegra/tegra_i2s_audio.c b/arch/arm/mach-tegra/tegra_i2s_audio.c index 40653570f87a..47626e103e8d 100644 --- a/arch/arm/mach-tegra/tegra_i2s_audio.c +++ b/arch/arm/mach-tegra/tegra_i2s_audio.c @@ -1262,6 +1262,26 @@ static long tegra_audio_out_ioctl(struct file *file, if (!rc) aos->errors = 0; break; + case TEGRA_AUDIO_OUT_PRELOAD_FIFO: { + struct tegra_audio_out_preload preload; + if (copy_from_user(&preload, (void __user *)arg, + sizeof(preload))) { + rc = -EFAULT; + break; + } + rc = kfifo_from_user(&ads->out.fifo, + (void __user *)preload.data, preload.len, + &preload.len_written); + if (rc < 0) { + pr_err("%s: error copying from user\n", __func__); + break; + } + if (copy_to_user((void __user *)arg, &preload, sizeof(preload))) + rc = -EFAULT; + pr_info("%s: preloaded output fifo with %d bytes\n", __func__, + preload.len_written); + } + break; default: rc = -EINVAL; } -- cgit v1.2.3