[RFC 10/12] omap: mcbsp: Move sidetone clock management to mach-omap2/mcbsp.c

[Jarkko Nikula <jhnikula@gmail.com>]

Active sidetone requires that McBSP interface clock doesn't idle and there
is no mechanism in hwmod to turn autoidling on/off in runtime. McBSP2 and 3
in OMAP34xx share their interface clock with McBSP sidetone module and
that interface clock must be active when the sidetone is operating.

Sidetone has its own autoidle bit which should keep the interface clock
active but it is broken. Putting the McBSP core to no-idle mode when the
sidetone is active is no good either since it results to higher power
consumption when using the threshold based DMA transfers.

For making the McBSP code more generic, move this sidetone clock management
with fixme comments to mach-omap2/mcbsp.c and pass pointer to it via
platform data.

Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
Cc: Paul Wamsley <paul@pwsan.com>
---
 arch/arm/mach-omap2/mcbsp.c             |   26 ++++++++++++++++++++++++++
 arch/arm/plat-omap/include/plat/mcbsp.h |    1 +
 arch/arm/plat-omap/mcbsp.c              |   18 ++++--------------
 3 files changed, 31 insertions(+), 14 deletions(-)

diff --git a/arch/arm/mach-omap2/mcbsp.c b/arch/arm/mach-omap2/mcbsp.c
index 1408156..88ee00f 100644
--- a/arch/arm/mach-omap2/mcbsp.c
+++ b/arch/arm/mach-omap2/mcbsp.c
@@ -27,6 +27,13 @@
 
 #include "control.h"
 
+/*
+ * FIXME: Find a mechanism to enable/disable runtime the McBSP ICLK autoidle.
+ * Sidetone needs non-gated ICLK and sidetone autoidle is broken.
+ */
+#include "cm2xxx_3xxx.h"
+#include "cm-regbits-34xx.h"
+
 /* McBSP internal signal muxing functions */
 
 void omap2_mcbsp1_mux_clkr_src(u8 mux)
@@ -102,6 +109,24 @@ int omap2_mcbsp_set_clks_src(u8 id, u8 fck_src_id)
 }
 EXPORT_SYMBOL(omap2_mcbsp_set_clks_src);
 
+static int omap3_enable_st_clock(unsigned int id, bool enable)
+{
+	unsigned int w;
+
+	/*
+	 * Sidetone uses McBSP ICLK - which must not idle when sidetones
+	 * are enabled or sidetones start sounding ugly.
+	 */
+	w = omap2_cm_read_mod_reg(OMAP3430_PER_MOD, CM_AUTOIDLE);
+	if (enable)
+		w &= ~(1 << (id - 2));
+	else
+		w |= 1 << (id - 2);
+	omap2_cm_write_mod_reg(w, OMAP3430_PER_MOD, CM_AUTOIDLE);
+
+	return 0;
+}
+
 struct omap_device_pm_latency omap2_mcbsp_latency[] = {
 	{
 		.deactivate_func = omap_device_idle_hwmods,
@@ -149,6 +174,7 @@ static int omap_init_mcbsp(struct omap_hwmod *oh, void *unused)
 	if (oh->dev_attr) {
 		oh_device[1] = omap_hwmod_lookup((
 		(struct omap_mcbsp_dev_attr *)(oh->dev_attr))->sidetone);
+		pdata->enable_st_clock = omap3_enable_st_clock;
 		count++;
 	}
 	od = omap_device_build_ss(name, id, oh_device, count, pdata,
diff --git a/arch/arm/plat-omap/include/plat/mcbsp.h b/arch/arm/plat-omap/include/plat/mcbsp.h
index 31b24c9..2a7e8d5 100644
--- a/arch/arm/plat-omap/include/plat/mcbsp.h
+++ b/arch/arm/plat-omap/include/plat/mcbsp.h
@@ -317,6 +317,7 @@ struct omap_mcbsp_platform_data {
 #ifdef CONFIG_ARCH_OMAP3
 	/* Sidetone block for McBSP 2 and 3 */
 	unsigned long phys_base_st;
+	int (*enable_st_clock)(unsigned int, bool);
 #endif
 	u16 buffer_size;
 	unsigned int mcbsp_config_type;
diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c
index 202292a..1a7cfb3 100644
--- a/arch/arm/plat-omap/mcbsp.c
+++ b/arch/arm/plat-omap/mcbsp.c
@@ -26,10 +26,6 @@
 #include <plat/mcbsp.h>
 #include <linux/pm_runtime.h>
 
-/* XXX These "sideways" includes are a sign that something is wrong */
-#include "../mach-omap2/cm2xxx_3xxx.h"
-#include "../mach-omap2/cm-regbits-34xx.h"
-
 struct omap_mcbsp **mcbsp_ptr;
 int omap_mcbsp_count, omap_mcbsp_cache_size;
 
@@ -267,13 +263,8 @@ static void omap_st_on(struct omap_mcbsp *mcbsp)
 {
 	unsigned int w;
 
-	/*
-	 * Sidetone uses McBSP ICLK - which must not idle when sidetones
-	 * are enabled or sidetones start sounding ugly.
-	 */
-	w = omap2_cm_read_mod_reg(OMAP3430_PER_MOD, CM_AUTOIDLE);
-	w &= ~(1 << (mcbsp->id - 2));
-	omap2_cm_write_mod_reg(w, OMAP3430_PER_MOD, CM_AUTOIDLE);
+	if (mcbsp->pdata->enable_st_clock)
+		mcbsp->pdata->enable_st_clock(mcbsp->id, 1);
 
 	/* Enable McBSP Sidetone */
 	w = MCBSP_READ(mcbsp, SSELCR);
@@ -294,9 +285,8 @@ static void omap_st_off(struct omap_mcbsp *mcbsp)
 	w = MCBSP_READ(mcbsp, SSELCR);
 	MCBSP_WRITE(mcbsp, SSELCR, w & ~(SIDETONEEN));
 
-	w = omap2_cm_read_mod_reg(OMAP3430_PER_MOD, CM_AUTOIDLE);
-	w |= 1 << (mcbsp->id - 2);
-	omap2_cm_write_mod_reg(w, OMAP3430_PER_MOD, CM_AUTOIDLE);
+	if (mcbsp->pdata->enable_st_clock)
+		mcbsp->pdata->enable_st_clock(mcbsp->id, 0);
 }
 
 static void omap_st_fir_write(struct omap_mcbsp *mcbsp, s16 *fir)
-- 
1.7.0.4