On Tue, 2010-03-02 at 14:39 +0100, Ujfalusi Peter (Nokia-D/Tampere) wrote:
New function for reading the XBUFFSTAT register, which holds the fill state of the transmit buffer on McBSP.
Signed-off-by: Peter Ujfalusi peter.ujfalusi@nokia.com
Reading the XBUFFSTAT register is by no means accurate. IIRC, it reports the buffer status incorrectly about 1/50 times on average (@ 48000khz); with simple math, it may be read during the DMA burst. Or is it guaranteed not being read during DMA transfer / have you otherwise verified the behavior?
- Eero
arch/arm/plat-omap/include/plat/mcbsp.h | 4 ++++ arch/arm/plat-omap/mcbsp.c | 27 +++++++++++++++++++++++++++ 2 files changed, 31 insertions(+), 0 deletions(-)
diff --git a/arch/arm/plat-omap/include/plat/mcbsp.h b/arch/arm/plat-omap/include/plat/mcbsp.h index 4f22e5b..98de3d4 100644 --- a/arch/arm/plat-omap/include/plat/mcbsp.h +++ b/arch/arm/plat-omap/include/plat/mcbsp.h @@ -147,6 +147,8 @@ #define OMAP_MCBSP_REG_WAKEUPEN 0xA8 #define OMAP_MCBSP_REG_XCCR 0xAC #define OMAP_MCBSP_REG_RCCR 0xB0 +#define OMAP_MCBSP_REG_XBUFFSTAT 0xB4 +#define OMAP_MCBSP_REG_RBUFFSTAT 0xB8
#define AUDIO_MCBSP_DATAWRITE (OMAP24XX_MCBSP2_BASE + OMAP_MCBSP_REG_DXR1) #define AUDIO_MCBSP_DATAREAD (OMAP24XX_MCBSP2_BASE + OMAP_MCBSP_REG_DRR1) @@ -428,6 +430,7 @@ void omap_mcbsp_set_tx_threshold(unsigned int id, u16 threshold); void omap_mcbsp_set_rx_threshold(unsigned int id, u16 threshold); u16 omap_mcbsp_get_max_tx_threshold(unsigned int id); u16 omap_mcbsp_get_max_rx_threshold(unsigned int id); +u16 omap_mcbsp_get_tx_buffstat(unsigned int id); int omap_mcbsp_get_dma_op_mode(unsigned int id); #else static inline void omap_mcbsp_set_tx_threshold(unsigned int id, u16 threshold) @@ -436,6 +439,7 @@ static inline void omap_mcbsp_set_rx_threshold(unsigned int id, u16 threshold) { } static inline u16 omap_mcbsp_get_max_tx_threshold(unsigned int id) { return 0; } static inline u16 omap_mcbsp_get_max_rx_threshold(unsigned int id) { return 0; } +static inline u16 omap_mcbsp_get_tx_buffstat(unsigned int id) { return 0; } static inline int omap_mcbsp_get_dma_op_mode(unsigned int id) { return 0; } #endif int omap_mcbsp_request(unsigned int id); diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c index f757672..e49af86 100644 --- a/arch/arm/plat-omap/mcbsp.c +++ b/arch/arm/plat-omap/mcbsp.c @@ -284,6 +284,33 @@ u16 omap_mcbsp_get_max_rx_threshold(unsigned int id) EXPORT_SYMBOL(omap_mcbsp_get_max_rx_threshold);
/*
- omap_mcbsp_get_tx_buffstat returns the number of used slots in the McBSP FIFO
- */
+u16 omap_mcbsp_get_tx_buffstat(unsigned int id) +{
- struct omap_mcbsp *mcbsp;
- u16 buffstat;
- if (!omap_mcbsp_check_valid_id(id)) {
printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);return -ENODEV;- }
- mcbsp = id_to_mcbsp_ptr(id);
- /* Returns the number of free locations in the buffer */
- buffstat = OMAP_MCBSP_READ(mcbsp->io_base, XBUFFSTAT);
- /* Number of free slots on McBSP ports */
- if (mcbsp->id == 2)
buffstat = 0x500 - buffstat;- else
buffstat = 0x80 - buffstat;- return buffstat;
+} +EXPORT_SYMBOL(omap_mcbsp_get_tx_buffstat);
+/*
- omap_mcbsp_get_dma_op_mode just return the current configured
- operating mode for the mcbsp channel
*/