Blackfin arch: fix bugs and unify BFIN_KERNEL_CLOCK option

 - remove duplicated code and headers
 - add option allowing arbitrary SDRAM/DDR Timing parameters.
 - mark automatically calculated timings as EXPERIMENTAL
 - fix comment header block

Related to BUGs:
 - kernel boot up fails with CONFIG_BFIN_KERNEL_CLOCK item on.
 - kernel does not boot if re-program clocks

[ Mike Frysinger <vapier.adi@gmail.com>
 - fix comment header
 - mark do_sync static
 - document the DMA shutdown
 - simplify SIC_IWR handling
 - fix ANOMALY_05000265 handling to work as intended ]

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

3 files changed, 95 insertions, 1 deletions

diff --git a/arch/blackfin/mach-common/Makefile b/arch/blackfin/mach-common/Makefile
index 38911c6f964f..1f3228ed713f 100644
--- a/arch/blackfin/mach-common/Makefile
+++ b/arch/blackfin/mach-common/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_PM)          += pm.o dpmc_modes.o
 obj-$(CONFIG_CPU_FREQ)    += cpufreq.o
 obj-$(CONFIG_CPU_VOLTAGE) += dpmc.o
 obj-$(CONFIG_SMP)         += smp.o
+obj-$(CONFIG_BFIN_KERNEL_CLOCK) += clocks-init.o
diff --git a/arch/blackfin/mach-common/clocks-init.c b/arch/blackfin/mach-common/clocks-init.c
new file mode 100644
index 000000000000..39a94b3a2ed7
--- /dev/null
+++ b/arch/blackfin/mach-common/clocks-init.c
@@ -0,0 +1,93 @@
+/*
+ * arch/blackfin/mach-common/clocks-init.c - reprogram clocks / memory
+ *
+ * Copyright 2004-2008 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/blackfin.h>
+
+#include <asm/dma.h>
+#include <asm/clocks.h>
+#include <asm/mem_init.h>
+
+#define PLL_CTL_VAL \
+        (((CONFIG_VCO_MULT & 63) << 9) | CLKIN_HALF | \
+         (PLL_BYPASS << 8) | (ANOMALY_05000265 ? 0x8000 : 0))
+
+__attribute__((l1_text))
+static void do_sync(void)
+{
+        __builtin_bfin_ssync();
+}
+
+__attribute__((l1_text))
+void init_clocks(void)
+{
+        /* Kill any active DMAs as they may trigger external memory accesses
+         * in the middle of reprogramming things, and that'll screw us up.
+         * For example, any automatic DMAs left by U-Boot for splash screens.
+         */
+        size_t i;
+        for (i = 0; i < MAX_BLACKFIN_DMA_CHANNEL; ++i) {
+                struct dma_register *dma = dma_io_base_addr[i];
+                dma->cfg = 0;
+        }
+
+        do_sync();
+
+#ifdef SIC_IWR0
+        bfin_write_SIC_IWR0(IWR_ENABLE(0));
+# ifdef SIC_IWR1
+        /* BF52x system reset does not properly reset SIC_IWR1 which
+         * will screw up the bootrom as it relies on MDMA0/1 waking it
+         * up from IDLE instructions.  See this report for more info:
+         * http://blackfin.uclinux.org/gf/tracker/4323
+         */
+        if (ANOMALY_05000435)
+                bfin_write_SIC_IWR1(IWR_ENABLE(10) | IWR_ENABLE(11));
+        else
+                bfin_write_SIC_IWR1(IWR_DISABLE_ALL);
+# endif
+# ifdef SIC_IWR2
+        bfin_write_SIC_IWR2(IWR_DISABLE_ALL);
+# endif
+#else
+        bfin_write_SIC_IWR(IWR_ENABLE(0));
+#endif
+        do_sync();
+#ifdef EBIU_SDGCTL
+        bfin_write_EBIU_SDGCTL(bfin_read_EBIU_SDGCTL() | SRFS);
+        do_sync();
+#endif
+
+#ifdef CLKBUFOE
+        bfin_write16(VR_CTL, bfin_read_VR_CTL() | CLKBUFOE);
+        do_sync();
+        __asm__ __volatile__("IDLE;");
+#endif
+        bfin_write_PLL_LOCKCNT(0x300);
+        do_sync();
+        bfin_write16(PLL_CTL, PLL_CTL_VAL);
+        __asm__ __volatile__("IDLE;");
+        bfin_write_PLL_DIV(CONFIG_CCLK_ACT_DIV | CONFIG_SCLK_DIV);
+#ifdef EBIU_SDGCTL
+        bfin_write_EBIU_SDRRC(mem_SDRRC);
+        bfin_write_EBIU_SDGCTL(mem_SDGCTL);
+#else
+        bfin_write_EBIU_RSTCTL(bfin_read_EBIU_RSTCTL() & ~(SRREQ));
+        do_sync();
+        bfin_write_EBIU_RSTCTL(bfin_read_EBIU_RSTCTL() | 0x1);
+        bfin_write_EBIU_DDRCTL0(mem_DDRCTL0);
+        bfin_write_EBIU_DDRCTL1(mem_DDRCTL1);
+        bfin_write_EBIU_DDRCTL2(mem_DDRCTL2);
+#ifdef CONFIG_MEM_EBIU_DDRQUE
+        bfin_write_EBIU_DDRQUE(CONFIG_MEM_EBIU_DDRQUE);
+#endif
+#endif
+        do_sync();
+        bfin_read16(0);
+}
diff --git a/arch/blackfin/mach-common/head.S b/arch/blackfin/mach-common/head.S
index a621ae444810..e1e42c029e15 100644
--- a/arch/blackfin/mach-common/head.S
+++ b/arch/blackfin/mach-common/head.S
@@ -147,7 +147,7 @@ ENTRY(__start)
         /* Put The Code for PLL Programming and SDRAM Programming in L1 ISRAM */
         call _bfin_relocate_l1_mem;
 #ifdef CONFIG_BFIN_KERNEL_CLOCK
-        call _start_dma_code;
+        call _init_clocks;
 #endif
 
         /* This section keeps the processor in supervisor mode