Blackfin: bf54x: add kconfig for UART2/3 DMA channel assignments

The BF54x lacks dedicated DMA channels for the UART peripherals and need
to be muxed between others.  So add a kconfig option so people can select
which channels the UARTs will use so they can pick between SPORTs and the
less commonly used EPPI/PIXC peripherals.

Signed-off-by: steven miao <realmz6@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

4 files changed, 102 insertions, 21 deletions

diff --git a/arch/blackfin/kernel/bfin_dma_5xx.c b/arch/blackfin/kernel/bfin_dma_5xx.c
index 1e485dfdc9f2..6ce8dce753c9 100644
--- a/arch/blackfin/kernel/bfin_dma_5xx.c
+++ b/arch/blackfin/kernel/bfin_dma_5xx.c
@@ -84,6 +84,24 @@ static int __init proc_dma_init(void)
 late_initcall(proc_dma_init);
 #endif
 
+static void set_dma_peripheral_map(unsigned int channel, const char *device_id)
+{
+#ifdef CONFIG_BF54x
+        unsigned int per_map;
+
+        switch (channel) {
+                case CH_UART2_RX: per_map = 0xC << 12; break;
+                case CH_UART2_TX: per_map = 0xD << 12; break;
+                case CH_UART3_RX: per_map = 0xE << 12; break;
+                case CH_UART3_TX: per_map = 0xF << 12; break;
+                default:          return;
+        }
+
+        if (strncmp(device_id, "BFIN_UART", 9) == 0)
+                dma_ch[channel].regs->peripheral_map = per_map;
+#endif
+}
+
 /**
  *      request_dma - request a DMA channel
  *
@@ -111,19 +129,7 @@ int request_dma(unsigned int channel, const char *device_id)
                 return -EBUSY;
         }
 
-#ifdef CONFIG_BF54x
-        if (channel >= CH_UART2_RX && channel <= CH_UART3_TX) {
-                unsigned int per_map;
-                per_map = dma_ch[channel].regs->peripheral_map & 0xFFF;
-                if (strncmp(device_id, "BFIN_UART", 9) == 0)
-                        dma_ch[channel].regs->peripheral_map = per_map |
-                                ((channel - CH_UART2_RX + 0xC)<<12);
-                else
-                        dma_ch[channel].regs->peripheral_map = per_map |
-                                ((channel - CH_UART2_RX + 0x6)<<12);
-        }
-#endif
-
+        set_dma_peripheral_map(channel, device_id);
         dma_ch[channel].device_id = device_id;
         dma_ch[channel].irq = 0;
 
diff --git a/arch/blackfin/mach-bf548/Kconfig b/arch/blackfin/mach-bf548/Kconfig
index 70189a0d1a19..94acb586832e 100644
--- a/arch/blackfin/mach-bf548/Kconfig
+++ b/arch/blackfin/mach-bf548/Kconfig
@@ -42,6 +42,65 @@ config BF548_ATAPI_ALTERNATIVE_PORT
           async address or GPIO port F and G. Select y to route it
           to GPIO.
 
+choice
+        prompt "UART2 DMA channel selection"
+        depends on SERIAL_BFIN_UART2
+        default UART2_DMA_RX_ON_DMA18
+        help
+                UART2 DMA channel selection
+                RX -> DMA18
+                TX -> DMA19
+                or
+                RX -> DMA13
+                TX -> DMA14
+
+config UART2_DMA_RX_ON_DMA18
+        bool "UART2 DMA RX -> DMA18 TX -> DMA19"
+        help
+                UART2 DMA channel assignment
+                RX -> DMA18
+                TX -> DMA19
+                use SPORT2 default DMA channel
+
+config UART2_DMA_RX_ON_DMA13
+        bool "UART2 DMA RX -> DMA13 TX -> DMA14"
+        help
+                UART2 DMA channel assignment
+                RX -> DMA13
+                TX -> DMA14
+                use EPPI1 EPPI2 default DMA channel
+endchoice
+
+choice
+        prompt "UART3 DMA channel selection"
+        depends on SERIAL_BFIN_UART3
+        default UART3_DMA_RX_ON_DMA20
+        help
+                UART3 DMA channel selection
+                RX -> DMA20
+                TX -> DMA21
+                or
+                RX -> DMA15
+                TX -> DMA16
+
+config UART3_DMA_RX_ON_DMA20
+        bool "UART3 DMA RX -> DMA20 TX -> DMA21"
+        help
+                UART3 DMA channel assignment
+                RX -> DMA20
+                TX -> DMA21
+                use SPORT3 default DMA channel
+
+config UART3_DMA_RX_ON_DMA15
+        bool "UART3 DMA RX -> DMA15 TX -> DMA16"
+        help
+                UART3 DMA channel assignment
+                RX -> DMA15
+                TX -> DMA16
+                use PIXC default DMA channel
+
+endchoice
+
 comment "Interrupt Priority Assignment"
 menu "Priority"
 
diff --git a/arch/blackfin/mach-bf548/include/mach/dma.h b/arch/blackfin/mach-bf548/include/mach/dma.h
index a30d242c7398..1a1091b071fd 100644
--- a/arch/blackfin/mach-bf548/include/mach/dma.h
+++ b/arch/blackfin/mach-bf548/include/mach/dma.h
@@ -27,17 +27,37 @@
 #define CH_PIXC_OVERLAY         16
 #define CH_PIXC_OUTPUT          17
 #define CH_SPORT2_RX            18
-#define CH_UART2_RX             18
 #define CH_SPORT2_TX            19
-#define CH_UART2_TX             19
 #define CH_SPORT3_RX            20
-#define CH_UART3_RX             20
 #define CH_SPORT3_TX            21
-#define CH_UART3_TX             21
 #define CH_SDH                  22
 #define CH_NFC                  22
 #define CH_SPI2                 23
 
+#if defined(CONFIG_UART2_DMA_RX_ON_DMA13)
+#define CH_UART2_RX             13
+#define IRQ_UART2_RX            BFIN_IRQ(37)    /* UART2 RX USE EPP1 (DMA13) Interrupt */
+#define CH_UART2_TX             14
+#define IRQ_UART2_TX            BFIN_IRQ(38)    /* UART2 RX USE EPP1 (DMA14) Interrupt */
+#else                                           /* Default USE SPORT2's DMA Channel */
+#define CH_UART2_RX             18
+#define IRQ_UART2_RX            BFIN_IRQ(33)    /* UART2 RX (DMA18) Interrupt */
+#define CH_UART2_TX             19
+#define IRQ_UART2_TX            BFIN_IRQ(34)    /* UART2 TX (DMA19) Interrupt */
+#endif
+
+#if defined(CONFIG_UART3_DMA_RX_ON_DMA15)
+#define CH_UART3_RX             15
+#define IRQ_UART3_RX            BFIN_IRQ(64)    /* UART3 RX USE PIXC IN0 (DMA15) Interrupt */
+#define CH_UART3_TX             16
+#define IRQ_UART3_TX            BFIN_IRQ(65)    /* UART3 TX USE PIXC IN1 (DMA16) Interrupt */
+#else                                           /* Default USE SPORT3's DMA Channel */
+#define CH_UART3_RX             20
+#define IRQ_UART3_RX            BFIN_IRQ(35)    /* UART3 RX (DMA20) Interrupt */
+#define CH_UART3_TX             21
+#define IRQ_UART3_TX            BFIN_IRQ(36)    /* UART3 TX (DMA21) Interrupt */
+#endif
+
 #define CH_MEM_STREAM0_DEST     24
 #define CH_MEM_STREAM0_SRC      25
 #define CH_MEM_STREAM1_DEST     26
diff --git a/arch/blackfin/mach-bf548/include/mach/irq.h b/arch/blackfin/mach-bf548/include/mach/irq.h
index 99fd1b2c53d8..7f87787e7738 100644
--- a/arch/blackfin/mach-bf548/include/mach/irq.h
+++ b/arch/blackfin/mach-bf548/include/mach/irq.h
@@ -74,13 +74,9 @@ Events         (highest priority)  EMU         0
 #define IRQ_UART2_ERROR         BFIN_IRQ(31)    /* UART2 Status (Error) Interrupt */
 #define IRQ_CAN0_ERROR          BFIN_IRQ(32)    /* CAN0 Status (Error) Interrupt */
 #define IRQ_SPORT2_RX           BFIN_IRQ(33)    /* SPORT2 RX (DMA18) Interrupt */
-#define IRQ_UART2_RX            BFIN_IRQ(33)    /* UART2 RX (DMA18) Interrupt */
 #define IRQ_SPORT2_TX           BFIN_IRQ(34)    /* SPORT2 TX (DMA19) Interrupt */
-#define IRQ_UART2_TX            BFIN_IRQ(34)    /* UART2 TX (DMA19) Interrupt */
 #define IRQ_SPORT3_RX           BFIN_IRQ(35)    /* SPORT3 RX (DMA20) Interrupt */
-#define IRQ_UART3_RX            BFIN_IRQ(35)    /* UART3 RX (DMA20) Interrupt */
 #define IRQ_SPORT3_TX           BFIN_IRQ(36)    /* SPORT3 TX (DMA21) Interrupt */
-#define IRQ_UART3_TX            BFIN_IRQ(36)    /* UART3 TX (DMA21) Interrupt */
 #define IRQ_EPPI1               BFIN_IRQ(37)    /* EPP1 (DMA13) Interrupt */
 #define IRQ_EPPI2               BFIN_IRQ(38)    /* EPP2 (DMA14) Interrupt */
 #define IRQ_SPI1                BFIN_IRQ(39)    /* SPI1 (DMA5) Interrupt */