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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 02:20:36 +0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 02:20:36 +0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/sparc/kernel/tadpole.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/sparc/kernel/tadpole.c')
-rw-r--r--arch/sparc/kernel/tadpole.c126
1 files changed, 126 insertions, 0 deletions
diff --git a/arch/sparc/kernel/tadpole.c b/arch/sparc/kernel/tadpole.c
new file mode 100644
index 000000000000..f476a5f4af6a
--- /dev/null
+++ b/arch/sparc/kernel/tadpole.c
@@ -0,0 +1,126 @@
+/* tadpole.c: Probing for the tadpole clock stopping h/w at boot time.
+ *
+ * Copyright (C) 1996 David Redman (djhr@tadpole.co.uk)
+ */
+
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+
+#include <asm/asi.h>
+#include <asm/oplib.h>
+#include <asm/io.h>
+
+#define MACIO_SCSI_CSR_ADDR 0x78400000
+#define MACIO_EN_DMA 0x00000200
+#define CLOCK_INIT_DONE 1
+
+static int clk_state;
+static volatile unsigned char *clk_ctrl;
+void (*cpu_pwr_save)(void);
+
+static inline unsigned int ldphys(unsigned int addr)
+{
+ unsigned long data;
+
+ __asm__ __volatile__("\n\tlda [%1] %2, %0\n\t" :
+ "=r" (data) :
+ "r" (addr), "i" (ASI_M_BYPASS));
+ return data;
+}
+
+static void clk_init(void)
+{
+ __asm__ __volatile__("mov 0x6c, %%g1\n\t"
+ "mov 0x4c, %%g2\n\t"
+ "mov 0xdf, %%g3\n\t"
+ "stb %%g1, [%0+3]\n\t"
+ "stb %%g2, [%0+3]\n\t"
+ "stb %%g3, [%0+3]\n\t" : :
+ "r" (clk_ctrl) :
+ "g1", "g2", "g3");
+}
+
+static void clk_slow(void)
+{
+ __asm__ __volatile__("mov 0xcc, %%g2\n\t"
+ "mov 0x4c, %%g3\n\t"
+ "mov 0xcf, %%g4\n\t"
+ "mov 0xdf, %%g5\n\t"
+ "stb %%g2, [%0+3]\n\t"
+ "stb %%g3, [%0+3]\n\t"
+ "stb %%g4, [%0+3]\n\t"
+ "stb %%g5, [%0+3]\n\t" : :
+ "r" (clk_ctrl) :
+ "g2", "g3", "g4", "g5");
+}
+
+/*
+ * Tadpole is guaranteed to be UP, using local_irq_save.
+ */
+static void tsu_clockstop(void)
+{
+ unsigned int mcsr;
+ unsigned long flags;
+
+ if (!clk_ctrl)
+ return;
+ if (!(clk_state & CLOCK_INIT_DONE)) {
+ local_irq_save(flags);
+ clk_init();
+ clk_state |= CLOCK_INIT_DONE; /* all done */
+ local_irq_restore(flags);
+ return;
+ }
+ if (!(clk_ctrl[2] & 1))
+ return; /* no speed up yet */
+
+ local_irq_save(flags);
+
+ /* if SCSI DMA in progress, don't slow clock */
+ mcsr = ldphys(MACIO_SCSI_CSR_ADDR);
+ if ((mcsr&MACIO_EN_DMA) != 0) {
+ local_irq_restore(flags);
+ return;
+ }
+ /* TODO... the minimum clock setting ought to increase the
+ * memory refresh interval..
+ */
+ clk_slow();
+ local_irq_restore(flags);
+}
+
+static void swift_clockstop(void)
+{
+ if (!clk_ctrl)
+ return;
+ clk_ctrl[0] = 0;
+}
+
+void __init clock_stop_probe(void)
+{
+ unsigned int node, clk_nd;
+ char name[20];
+
+ prom_getstring(prom_root_node, "name", name, sizeof(name));
+ if (strncmp(name, "Tadpole", 7))
+ return;
+ node = prom_getchild(prom_root_node);
+ node = prom_searchsiblings(node, "obio");
+ node = prom_getchild(node);
+ clk_nd = prom_searchsiblings(node, "clk-ctrl");
+ if (!clk_nd)
+ return;
+ printk("Clock Stopping h/w detected... ");
+ clk_ctrl = (char *) prom_getint(clk_nd, "address");
+ clk_state = 0;
+ if (name[10] == '\0') {
+ cpu_pwr_save = tsu_clockstop;
+ printk("enabled (S3)\n");
+ } else if ((name[10] == 'X') || (name[10] == 'G')) {
+ cpu_pwr_save = swift_clockstop;
+ printk("enabled (%s)\n",name+7);
+ } else
+ printk("disabled %s\n",name+7);
+}