OMAP: McBSP: Add transmit/receive threshold handler

This patch adds a way to handle transmit/receive threshold.
It export to mcbsp users a callback registration procedure.
Signed-off-by: Eduardo Valentin <eduardo.valentin@nokia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

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

@@ -389,6 +389,15 @@ int omap_mcbsp_init(void);
 void omap_mcbsp_register_board_cfg(struct omap_mcbsp_platform_data *config,
 					int size);
 void omap_mcbsp_config(unsigned int id, const struct omap_mcbsp_reg_cfg * config);
+#ifdef CONFIG_ARCH_OMAP34XX
+void omap_mcbsp_set_tx_threshold(unsigned int id, u16 threshold);
+void omap_mcbsp_set_rx_threshold(unsigned int id, u16 threshold);
+#else
+static inline void omap_mcbsp_set_tx_threshold(unsigned int id, u16 threshold)
+{ }
+static inline void omap_mcbsp_set_rx_threshold(unsigned int id, u16 threshold)
+{ }
+#endif
 int omap_mcbsp_request(unsigned int id);
 void omap_mcbsp_free(unsigned int id);
 void omap_mcbsp_start(unsigned int id, int tx, int rx);

arch/arm/plat-omap/mcbsp.c

@@ -198,6 +198,56 @@ void omap_mcbsp_config(unsigned int id, const struct omap_mcbsp_reg_cfg *config)
 }
 EXPORT_SYMBOL(omap_mcbsp_config);
 
+#ifdef CONFIG_ARCH_OMAP34XX
+/*
+ * omap_mcbsp_set_tx_threshold configures how to deal
+ * with transmit threshold. the threshold value and handler can be
+ * configure in here.
+ */
+void omap_mcbsp_set_tx_threshold(unsigned int id, u16 threshold)
+{
+	struct omap_mcbsp *mcbsp;
+	void __iomem *io_base;
+
+	if (!cpu_is_omap34xx())
+		return;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+	io_base = mcbsp->io_base;
+
+	OMAP_MCBSP_WRITE(io_base, THRSH2, threshold);
+}
+EXPORT_SYMBOL(omap_mcbsp_set_tx_threshold);
+
+/*
+ * omap_mcbsp_set_rx_threshold configures how to deal
+ * with receive threshold. the threshold value and handler can be
+ * configure in here.
+ */
+void omap_mcbsp_set_rx_threshold(unsigned int id, u16 threshold)
+{
+	struct omap_mcbsp *mcbsp;
+	void __iomem *io_base;
+
+	if (!cpu_is_omap34xx())
+		return;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+	io_base = mcbsp->io_base;
+
+	OMAP_MCBSP_WRITE(io_base, THRSH1, threshold);
+}
+EXPORT_SYMBOL(omap_mcbsp_set_rx_threshold);
+#endif
+
 /*
  * We can choose between IRQ based or polled IO.
  * This needs to be called before omap_mcbsp_request().