omap: McBSP: Introduce caching in register write operations

Determine cache size required per McBSP port at init time, based on
processor type running on.

Allocate space for storing cached copies of McBSP register values at
port request.

Modify omap_msbcp_write() function to update the cache with every
register write operation.

Modify omap_mcbsp_read() to support reading from cache or hardware.

Update MCBSP_READ() macro for modified omap_mcbsp_read() function API.

Introduce a new macro that reads from the cache.

Tested on OMAP1510 based Amstrad Delta using linux-omap for-next, commit
fb7380d70e041e4b3892f6b19dff7efb609d15a4 (2.6.33-rc3+ dated 2010-01-11).
Compile-tested with: omap_perseus2_730_defconfig, omap_generic_1610_defconfig,
omap_generic_2420_defconfig, omap_2430sdp_defconfig, omap_3430sdp_defconfig,
omap_4430sdp_defconfig with CONFIG_OMAP_MCBSP=y selected.

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Acked-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Acked-by: Jarkko Nikula <jhnikula@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 13 insertions, 3 deletions

diff --git a/arch/arm/mach-omap1/mcbsp.c b/arch/arm/mach-omap1/mcbsp.c
index 6bddce104ee9..f9a5cf750b59 100644
--- a/arch/arm/mach-omap1/mcbsp.c
+++ b/arch/arm/mach-omap1/mcbsp.c
@@ -99,9 +99,11 @@ static struct omap_mcbsp_platform_data omap7xx_mcbsp_pdata[] = {
         },
 };
 #define OMAP7XX_MCBSP_PDATA_SZ          ARRAY_SIZE(omap7xx_mcbsp_pdata)
+#define OMAP7XX_MCBSP_REG_NUM           (OMAP_MCBSP_REG_XCERH / sizeof(u16) + 1)
 #else
 #define omap7xx_mcbsp_pdata             NULL
 #define OMAP7XX_MCBSP_PDATA_SZ          0
+#define OMAP7XX_MCBSP_REG_NUM           0
 #endif
 
 #ifdef CONFIG_ARCH_OMAP15XX
@@ -132,9 +134,11 @@ static struct omap_mcbsp_platform_data omap15xx_mcbsp_pdata[] = {
         },
 };
 #define OMAP15XX_MCBSP_PDATA_SZ         ARRAY_SIZE(omap15xx_mcbsp_pdata)
+#define OMAP15XX_MCBSP_REG_NUM          (OMAP_MCBSP_REG_XCERH / sizeof(u16) + 1)
 #else
 #define omap15xx_mcbsp_pdata            NULL
 #define OMAP15XX_MCBSP_PDATA_SZ         0
+#define OMAP15XX_MCBSP_REG_NUM          0
 #endif
 
 #ifdef CONFIG_ARCH_OMAP16XX
@@ -165,19 +169,25 @@ static struct omap_mcbsp_platform_data omap16xx_mcbsp_pdata[] = {
         },
 };
 #define OMAP16XX_MCBSP_PDATA_SZ         ARRAY_SIZE(omap16xx_mcbsp_pdata)
+#define OMAP16XX_MCBSP_REG_NUM          (OMAP_MCBSP_REG_XCERH / sizeof(u16) + 1)
 #else
 #define omap16xx_mcbsp_pdata            NULL
 #define OMAP16XX_MCBSP_PDATA_SZ         0
+#define OMAP16XX_MCBSP_REG_NUM          0
 #endif
 
 int __init omap1_mcbsp_init(void)
 {
-        if (cpu_is_omap7xx())
+        if (cpu_is_omap7xx()) {
                 omap_mcbsp_count = OMAP7XX_MCBSP_PDATA_SZ;
-        if (cpu_is_omap15xx())
+                omap_mcbsp_cache_size = OMAP7XX_MCBSP_REG_NUM * sizeof(u16);
+        } else if (cpu_is_omap15xx()) {
                 omap_mcbsp_count = OMAP15XX_MCBSP_PDATA_SZ;
-        if (cpu_is_omap16xx())
+                omap_mcbsp_cache_size = OMAP15XX_MCBSP_REG_NUM * sizeof(u16);
+        } else if (cpu_is_omap16xx()) {
                 omap_mcbsp_count = OMAP16XX_MCBSP_PDATA_SZ;
+                omap_mcbsp_cache_size = OMAP16XX_MCBSP_REG_NUM * sizeof(u16);
+        }
 
         mcbsp_ptr = kzalloc(omap_mcbsp_count * sizeof(struct omap_mcbsp *),
                                                                 GFP_KERNEL);