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* ASoC: Tegra: I2S: Ensure clock is enabled when writing regsStephen Warren2011-07-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | The I2S controller needs a clock to respond to register writes. Without this, register writes will at worst hang the CPU. In practice, I've only observed writes being dropped. Luckily, the dropped register writes historically had no effect: TEGRA_I2S_TIMING: The value we wrote was the reset default. TEGRA_I2S_FIFO_SCR: The default was for the FIFOs to request more data when one slot was empty. The requested value was for the FIFOs to request when four slots were empty. The DMA controller in the mainline kernel is configured to burst a single entry at a time into the FIFO, hence there was no issue. The only negative effect was on bus efficiency losses due to an increased number of arbitration attempts. However, in various non-upstream changes, the DMA controller now bursts four entries at a time into the FIFO. If there is only space for one entry, the data is simply dropped. In practice, this resulted in 3/4 of samples being dropped, and playback at 4x the expected rate and pitch. By fixing the clocking issue, this is solved. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Liam Girdwood <lrg@ti.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
* ASoC: Tegra: Fix compile when debugfs not enabledStephen Warren2011-05-20
| | | | | | | | | | The prototype of the inline dummy version of tegra_i2s_debug_add was not consistent with the real version. Reported-by: Rhyland-Klein <rklein@nvidia.com> Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Liam Girdwood <lrg@ti.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
* ASoC: Tegra: Add MODULE_ALIASStephen Warren2011-02-13
| | | | | | | | With the appropriate MODULE_ALIAS in place, the audio modules will be automatically loaded; there is no longer a need for manual modprobes. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
* ASoC: Tegra: I2S: Use dev_err not pr_errStephen Warren2011-01-31
| | | | | | Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Liam Girdwood <lrg@slimlogic.co.uk> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
* ASoC: tegra: s/IS_ERR_OR_NULL/IS_ERR/ for clk_get_sysStephen Warren2011-01-13
| | | | | | | | | | | | | | | | | A recent discussion on linux-arm-kernel noted that the value returned by clk_get_sys is an opaque token, and not strictly a pointer; it is meaningful only to the clock API, clients should not dereference the value, and the clock API must accept any non-IS_ERR value it returned. Hence, only IS_ERR is appropriate to interpret the result, not IS_ERR_OR_NULL. I checked that clk_get_sys in both ASoC's for-next and Tegra's for-next do behave as described; NULL is not returned in the case of error. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Liam Girdwood <lrg@slimlogic.co.uk> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
* ASoC: Update name of debugfs root symbol to snd_soc_Mark Brown2011-01-10
| | | | | | | Everything else is using snd_soc_ so we should use it here too. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
* ASoC: tegra: Add tegra-i2s driverStephen Warren2011-01-10
This provides an ASoC DAI interface for Tegra's I2S controller. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Liam Girdwood <lrg@slimlogic.co.uk> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>