* Add variable CPU clock for MPC859/866 systems (so far only TQM866M):

  see doc/README.MPC866 for details;
  implement workaround for "SIU4" and "SIU9" silicon bugs on MPC866;
  calculate CPU clock frequency from PLL register values.

* Add support for 128 MB RAM on TQM8xxL/M modules

1 files changed, 145 insertions, 0 deletions

diff --git a/cpu/mpc8xx/plprcr_write.S b/cpu/mpc8xx/plprcr_write.S
new file mode 100644
index 0000000000..7d39a0edf6
--- /dev/null
+++ b/cpu/mpc8xx/plprcr_write.S
@@ -0,0 +1,145 @@
+/*
+ * (C) Copyright 2004
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <mpc8xx.h>
+#include <ppc_asm.tmpl>
+#include <asm/cache.h>
+
+#define CACHE_CMD_ENABLE	0x02000000
+#define CACHE_CMD_DISABLE	0x04000000
+#define CACHE_CMD_LOAD_LOCK	0x06000000
+#define CACHE_CMD_UNLOCK_LINE	0x08000000
+#define CACHE_CMD_UNLOCK_ALL	0x0A000000
+#define CACHE_CMD_INVALIDATE	0x0C000000
+#define SPEED_PLPRCR_WAIT_5CYC	150
+#define _CACHE_ALIGN_SIZE	16
+
+
+	.text
+	.align 2
+	.globl plprcr_write_866
+
+/*
+ * void plprcr_write_866 (long plprcr)
+ * Write PLPRCR, including workaround for device errata SIU4 and SIU9.
+ */
+
+plprcr_write_866:
+	mfspr	r10, LR		/* save the Link Register value */
+
+	/* turn instruction cache on (no MMU required for instructions)
+	 */
+	lis	r4, CACHE_CMD_ENABLE@h
+	ori	r4, r4, CACHE_CMD_ENABLE@l
+	mtspr	IC_CST, r4
+	isync
+
+	/* clear IC_CST error bits
+	 */
+	mfspr	r4, IC_CST
+
+	bl	plprcr_here
+
+plprcr_here:
+	mflr	r5
+
+	/* calculate relocation offset
+	 */
+	lis	r4, plprcr_here@h
+	ori	r4, r4, plprcr_here@l
+	sub	r5, r5, r4
+
+	/* calculate first address of this function
+	 */
+	lis	r6, plprcr_write_866@h
+	ori	r6, r6, plprcr_write_866@l
+	add	r6, r6, r5
+
+	/* calculate end address of this function
+	 */
+	lis	r7, plprcr_end@h
+	ori	r7, r7, plprcr_end@l
+	add	r7, r7, r5
+
+	/* load and lock code addresses
+	 */
+	mr	r5, r6
+
+plprcr_loop:
+	mtspr	IC_ADR, r5
+	addi	r5, r5, _CACHE_ALIGN_SIZE	/* increment by one line */
+
+	lis	r4, CACHE_CMD_LOAD_LOCK@h
+	ori	r4, r4, CACHE_CMD_LOAD_LOCK@l
+	mtspr	IC_CST, r4
+	isync
+
+	cmpw	r5, r7
+	blt	plprcr_loop
+
+	/* IC_CST error bits not evaluated
+	 */
+
+	/* switch PLPRCR
+	 */
+	mfspr	r4, IMMR		/* read IMMR */
+	rlwinm	r4, r4, 0, 0, 15	/* only high 16 bits count */
+
+	/* write sequence according to MPC866 Errata
+	 */
+	stw	r3, PLPRCR(r4)
+	isync
+
+	lis	r3, SPEED_PLPRCR_WAIT_5CYC@h
+	ori	r3, r3, SPEED_PLPRCR_WAIT_5CYC@l
+
+plprcr_wait:
+	cmpwi	r3, 0
+	beq	plprcr_wait_end
+	nop
+	subi	r3, r3, 1
+	b	plprcr_wait
+
+plprcr_wait_end:
+
+	/* turn instruction cache off
+	 */
+	lis	r4, CACHE_CMD_UNLOCK_ALL@h
+	ori	r4, r4, CACHE_CMD_UNLOCK_ALL@l
+	mtspr	IC_CST, r4
+	isync
+
+	lis	r4, CACHE_CMD_INVALIDATE@h
+	ori	r4, r4, CACHE_CMD_INVALIDATE@l
+	mtspr	IC_CST, r4
+	isync
+
+	lis	r4, CACHE_CMD_DISABLE@h
+	ori	r4, r4, CACHE_CMD_DISABLE@l
+	mtspr	IC_CST, r4
+	isync
+
+	mtspr	LR, r10		/* restore original Link Register value */
+	blr
+
+plprcr_end: