p1022ds: allow for board-specific ngPIXIS functions

The ngPIXIS is an FPGA used on the reference boards of most Freescale PowerPC
SOCs.  Although programming the ngPIXIS is mostly standard on all boards that
have it, the P1022DS is unique in that the ngPIXIS needs to be programmed in
"indirect" mode whenever the video display (DIU) is active.

To support indirect mode, and to make it easier to support other quirks on
future reference boards, the low-level ngPIXIS functions are all marked as
weak, so that board-specific code can override any of them.  We take advantage
of this feature on the P1022DS, so that we can properly reset the board when
the DIU is active.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

board/freescale/common/ngpixis.c

@@ -1,5 +1,5 @@
 /**
- * Copyright 2010 Freescale Semiconductor
+ * Copyright 2010-2011 Freescale Semiconductor
  * Author: Timur Tabi <timur@freescale.com>
  *
  * This program is free software; you can redistribute it and/or modify it
@@ -35,61 +35,89 @@
 
 #include <common.h>
 #include <command.h>
-#include <watchdog.h>
-#include <asm/cache.h>
 #include <asm/io.h>
 
 #include "ngpixis.h"
 
+static u8 __pixis_read(unsigned int reg)
+{
+	void *p = (void *)PIXIS_BASE;
+
+	return in_8(p + reg);
+}
+u8 pixis_read(unsigned int reg) __attribute__((weak, alias("__pixis_read")));
+
+static void __pixis_write(unsigned int reg, u8 value)
+{
+	void *p = (void *)PIXIS_BASE;
+
+	out_8(p + reg, value);
+}
+void pixis_write(unsigned int reg, u8 value)
+	__attribute__((weak, alias("__pixis_write")));
+
 /*
  * Reset the board. This ignores the ENx registers.
  */
-void pixis_reset(void)
+void __pixis_reset(void)
 {
-	out_8(&pixis->rst, 0);
+	PIXIS_WRITE(rst, 0);
 
 	while (1);
 }
+void pixis_reset(void) __attribute__((weak, alias("__pixis_reset")));
 
 /*
  * Reset the board.  Like pixis_reset(), but it honors the ENx registers.
  */
-void pixis_bank_reset(void)
+void __pixis_bank_reset(void)
 {
-	out_8(&pixis->vctl, 0);
-	out_8(&pixis->vctl, 1);
+	PIXIS_WRITE(vctl, 0);
+	PIXIS_WRITE(vctl, 1);
 
 	while (1);
 }
+void pixis_bank_reset(void) __attribute__((weak, alias("__pixis_bank_reset")));
 
 /**
  * Set the boot bank to the power-on default bank
  */
-void clear_altbank(void)
+void __clear_altbank(void)
 {
+	u8 reg;
+
 	/* Tell the ngPIXIS to use this the bits in the physical switch for the
 	 * boot bank value, instead of the SWx register.  We need to be careful
 	 * only to set the bits in SWx that correspond to the boot bank.
 	 */
-	clrbits_8(&PIXIS_EN(PIXIS_LBMAP_SWITCH), PIXIS_LBMAP_MASK);
+	reg = PIXIS_READ(s[PIXIS_LBMAP_SWITCH - 1].en);
+	reg &= ~PIXIS_LBMAP_MASK;
+	PIXIS_WRITE(s[PIXIS_LBMAP_SWITCH - 1].en, reg);
 }
+void clear_altbank(void) __attribute__((weak, alias("__clear_altbank")));
 
 /**
  * Set the boot bank to the alternate bank
  */
-void set_altbank(void)
+void __set_altbank(void)
 {
+	u8 reg;
+
 	/* Program the alternate bank number into the SWx register.
 	 */
-	clrsetbits_8(&PIXIS_SW(PIXIS_LBMAP_SWITCH), PIXIS_LBMAP_MASK,
-		     PIXIS_LBMAP_ALTBANK);
+	reg = PIXIS_READ(s[PIXIS_LBMAP_SWITCH - 1].sw);
+	reg = (reg & ~PIXIS_LBMAP_MASK) | PIXIS_LBMAP_ALTBANK;
+	PIXIS_WRITE(s[PIXIS_LBMAP_SWITCH - 1].sw, reg);
 
 	/* Tell the ngPIXIS to use this the bits in the SWx register for the
 	 * boot bank value, instead of the physical switch.  We need to be
 	 * careful only to set the bits in SWx that correspond to the boot bank.
 	 */
-	setbits_8(&PIXIS_EN(PIXIS_LBMAP_SWITCH), PIXIS_LBMAP_MASK);
+	reg = PIXIS_READ(s[PIXIS_LBMAP_SWITCH - 1].en);
+	reg |= PIXIS_LBMAP_MASK;
+	PIXIS_WRITE(s[PIXIS_LBMAP_SWITCH - 1].en, reg);
 }
+void set_altbank(void) __attribute__((weak, alias("__set_altbank")));
 
 
 int pixis_reset_cmd(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])

board/freescale/common/ngpixis.h

@@ -1,5 +1,5 @@
 /**
- * Copyright 2010 Freescale Semiconductor
+ * Copyright 2010-2011 Freescale Semiconductor
  * Author: Timur Tabi <timur@freescale.com>
  *
  * This program is free software; you can redistribute it and/or modify it
@@ -55,3 +55,9 @@ typedef struct ngpixis {
 
 /* The PIXIS EN register that corresponds to board switch X, where x >= 1 */
 #define PIXIS_EN(x)		(pixis->s[(x) - 1].en)
+
+u8 pixis_read(unsigned int reg);
+void pixis_write(unsigned int reg, u8 value);
+
+#define PIXIS_READ(reg) pixis_read(offsetof(ngpixis_t, reg))
+#define PIXIS_WRITE(reg, value) pixis_write(offsetof(ngpixis_t, reg), value)

board/freescale/p1022ds/diu.c

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010 Freescale Semiconductor, Inc.
+ * Copyright 2010-2011 Freescale Semiconductor, Inc.
  * Authors: Timur Tabi <timur@freescale.com>
  *
  * FSL DIU Framebuffer driver
@@ -139,8 +139,6 @@ int platform_diu_init(unsigned int *xres, unsigned int *yres)
 	return fsl_diu_init(*xres, pixel_format, 0);
 }
 
-#ifdef CONFIG_CFI_FLASH_USE_WEAK_ACCESSORS
-
 /*
  * set_mux_to_lbc - disable the DIU so that we can read/write to elbc
  *
@@ -211,6 +209,68 @@ static void set_mux_to_diu(void)
 	in_be32(&gur->pmuxcr);
 }
 
+/*
+ * pixis_read - board-specific function to read from the PIXIS
+ *
+ * This function overrides the generic pixis_read() function, so that it can
+ * use PIXIS indirect mode if necessary.
+ */
+u8 pixis_read(unsigned int reg)
+{
+	ccsr_gur_t *gur = (void *)CONFIG_SYS_MPC85xx_GUTS_ADDR;
+
+	/* Use indirect mode if the mux is currently set to DIU mode */
+	if ((in_be32(&gur->pmuxcr) & PMUXCR_ELBCDIU_MASK) !=
+	    PMUXCR_ELBCDIU_NOR16) {
+		out_8(lbc_lcs0_ba, reg);
+		return in_8(lbc_lcs1_ba);
+	} else {
+		void *p = (void *)PIXIS_BASE;
+
+		return in_8(p + reg);
+	}
+}
+
+/*
+ * pixis_write - board-specific function to write to the PIXIS
+ *
+ * This function overrides the generic pixis_write() function, so that it can
+ * use PIXIS indirect mode if necessary.
+ */
+void pixis_write(unsigned int reg, u8 value)
+{
+	ccsr_gur_t *gur = (void *)CONFIG_SYS_MPC85xx_GUTS_ADDR;
+
+	/* Use indirect mode if the mux is currently set to DIU mode */
+	if ((in_be32(&gur->pmuxcr) & PMUXCR_ELBCDIU_MASK) !=
+	    PMUXCR_ELBCDIU_NOR16) {
+		out_8(lbc_lcs0_ba, reg);
+		out_8(lbc_lcs1_ba, value);
+		/* Do a read-back to ensure the write completed */
+		in_8(lbc_lcs1_ba);
+	} else {
+		void *p = (void *)PIXIS_BASE;
+
+		out_8(p + reg, value);
+	}
+}
+
+void pixis_bank_reset(void)
+{
+	/*
+	 * For some reason, a PIXIS bank reset does not work if the PIXIS is
+	 * in indirect mode, so switch to direct mode first.
+	 */
+	set_mux_to_lbc();
+
+	out_8(&pixis->vctl, 0);
+	out_8(&pixis->vctl, 1);
+
+	while (1);
+}
+
+#ifdef CONFIG_CFI_FLASH_USE_WEAK_ACCESSORS
+
 void flash_write8(u8 value, void *addr)
 {
 	int sw = set_mux_to_lbc();