sh: dma: Make PVR2 DMA configurable.

With arch/sh/drivers/dma/ always being built, the Dreamcast DMA engines
are being unconditionally built in, regardless of whether the DMA API is
enabled or not. This is a regression from previous behaviour, but there
is not much advantage in building them all in unconditionally regardless.
Add a new config option to make it optional, and update the only user of
it to reflect that.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/drivers/dma/Kconfig

@@ -54,4 +54,17 @@ config SH_DMABRG
 	  of the SH7760.
 	  Say Y if you want to use Audio/USB DMA on your SH7760 board.
 
+config PVR2_DMA
+	tristate "PowerVR 2 DMAC support"
+	depends on SH_DREAMCAST && SH_DMA
+	help
+	  Selecting this will enable support for the PVR2 DMA controller.
+	  As this chains off of the on-chip DMAC, that must also be
+	  enabled by default.
+
+	  This is primarily used by the pvr2fb framebuffer driver for
+	  certain optimizations, but is not necessary for functionality.
+
+	  If in doubt, say N.
+
 endmenu

arch/sh/drivers/dma/Makefile

@@ -4,5 +4,6 @@
 
 obj-$(CONFIG_SH_DMA_API)	+= dma-api.o dma-sysfs.o
 obj-$(CONFIG_SH_DMA)		+= dma-sh.o
-obj-$(CONFIG_SH_DREAMCAST)	+= dma-pvr2.o dma-g2.o
+obj-$(CONFIG_SH_DREAMCAST)	+= dma-g2.o
+obj-$(CONFIG_PVR2_DMA)		+= dma-pvr2.o
 obj-$(CONFIG_SH_DMABRG)		+= dmabrg.o

drivers/video/pvr2fb.c

@@ -61,7 +61,7 @@
 #include <mach-dreamcast/mach/sysasic.h>
 #endif
 
-#ifdef CONFIG_SH_DMA
+#ifdef CONFIG_PVR2_DMA
 #include <linux/pagemap.h>
 #include <mach/dma.h>
 #include <asm/dma.h>
@@ -188,7 +188,7 @@ static unsigned int is_blanked = 0;		/* Is the screen blanked? */
 static unsigned long pvr2fb_map;
 #endif
 
-#ifdef CONFIG_SH_DMA
+#ifdef CONFIG_PVR2_DMA
 static unsigned int shdma = PVR2_CASCADE_CHAN;
 static unsigned int pvr2dma = ONCHIP_NR_DMA_CHANNELS;
 #endif
@@ -207,7 +207,7 @@ static irqreturn_t pvr2fb_interrupt(int irq, void *dev_id);
 static int pvr2_init_cable(void);
 static int pvr2_get_param(const struct pvr2_params *p, const char *s,
                             int val, int size);
-#ifdef CONFIG_SH_DMA
+#ifdef CONFIG_PVR2_DMA
 static ssize_t pvr2fb_write(struct fb_info *info, const char *buf,
 			    size_t count, loff_t *ppos);
 #endif
@@ -218,7 +218,7 @@ static struct fb_ops pvr2fb_ops = {
 	.fb_blank	= pvr2fb_blank,
 	.fb_check_var	= pvr2fb_check_var,
 	.fb_set_par	= pvr2fb_set_par,
-#ifdef CONFIG_SH_DMA
+#ifdef CONFIG_PVR2_DMA
 	.fb_write	= pvr2fb_write,
 #endif
 	.fb_fillrect	= cfb_fillrect,
@@ -671,7 +671,7 @@ static int pvr2_init_cable(void)
 	return cable_type;
 }
 
-#ifdef CONFIG_SH_DMA
+#ifdef CONFIG_PVR2_DMA
 static ssize_t pvr2fb_write(struct fb_info *info, const char *buf,
 			    size_t count, loff_t *ppos)
 {
@@ -743,7 +743,7 @@ out_unmap:
 
 	return ret;
 }
-#endif /* CONFIG_SH_DMA */
+#endif /* CONFIG_PVR2_DMA */
 
 /**
  * pvr2fb_common_init
@@ -893,7 +893,7 @@ static int __init pvr2fb_dc_init(void)
 		return -EBUSY;
 	}
 
-#ifdef CONFIG_SH_DMA
+#ifdef CONFIG_PVR2_DMA
 	if (request_dma(pvr2dma, "pvr2") != 0) {
 		free_irq(HW_EVENT_VSYNC, 0);
 		return -EBUSY;
@@ -915,7 +915,7 @@ static void __exit pvr2fb_dc_exit(void)
 	}
 
 	free_irq(HW_EVENT_VSYNC, 0);
-#ifdef CONFIG_SH_DMA
+#ifdef CONFIG_PVR2_DMA
 	free_dma(pvr2dma);
 #endif
 }