OMAP: McBSP: Function to query the FIFO size

Users of McBSP can use the omap_mcbsp_get_fifo_size function to query
the size of the McBSP FIFO.
The function will return the FIFO size in words (the HW maximum).

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Acked-by: Jarkko Nikula <jhnikula@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolsfonmicro.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

arch/arm/plat-omap/include/plat/mcbsp.h

@@ -473,6 +473,7 @@ 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_fifo_size(unsigned int id);
 u16 omap_mcbsp_get_tx_delay(unsigned int id);
 u16 omap_mcbsp_get_rx_delay(unsigned int id);
 int omap_mcbsp_get_dma_op_mode(unsigned int id);
@@ -483,6 +484,7 @@ 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_fifo_size(unsigned int id) { return 0; }
 static inline u16 omap_mcbsp_get_tx_delay(unsigned int id) { return 0; }
 static inline u16 omap_mcbsp_get_rx_delay(unsigned int id) { return 0; }
 static inline int omap_mcbsp_get_dma_op_mode(unsigned int id) { return 0; }

arch/arm/plat-omap/mcbsp.c

@@ -560,6 +560,20 @@ u16 omap_mcbsp_get_max_rx_threshold(unsigned int id)
 }
 EXPORT_SYMBOL(omap_mcbsp_get_max_rx_threshold);
 
+u16 omap_mcbsp_get_fifo_size(unsigned int id)
+{
+	struct omap_mcbsp *mcbsp;
+
+	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);
+
+	return mcbsp->pdata->buffer_size;
+}
+EXPORT_SYMBOL(omap_mcbsp_get_fifo_size);
+
 #define MCBSP2_FIFO_SIZE	0x500 /* 1024 + 256 locations */
 #define MCBSP1345_FIFO_SIZE	0x80  /* 128 locations */
 /*