[U-Boot] [PATCH] powerpc/p1022ds: fix DIU/LBC switching with NAND enabled

[Timur Tabi]

In order for indirect mode on the PIXIS to work properly, both chip selects
need to be set to GPCM mode, otherwise writes to the chip select base
addresses will not actually post to the local bus -- they'll go to the
NAND controller instead.  Therefore, we need to set BR0 and BR1 to GPCM
mode before switching to indirect mode.

Signed-off-by: Timur Tabi <timur at freescale.com>
---
 board/freescale/p1022ds/diu.c |   82 +++++++++++++++++++++++++++++++++++++----
 1 files changed, 74 insertions(+), 8 deletions(-)

diff --git a/board/freescale/p1022ds/diu.c b/board/freescale/p1022ds/diu.c
index d5428ea..898f4c7 100644
--- a/board/freescale/p1022ds/diu.c
+++ b/board/freescale/p1022ds/diu.c
@@ -63,6 +63,8 @@ static u8 px_brdcfg0;
 static u32 pmuxcr;
 static void *lbc_lcs0_ba;
 static void *lbc_lcs1_ba;
+static u32 old_br0, old_or0, old_br1, old_or1;
+static u32 new_br0, new_or0, new_br1, new_or1;
 
 void diu_set_pixel_clock(unsigned int pixclock)
 {
@@ -88,10 +90,63 @@ int platform_diu_init(unsigned int xres, unsigned int yres, const char *port)
 	const char *name;
 	u32 pixel_format;
 	u8 temp;
+	phys_addr_t phys0, phys1; /* BR0/BR1 physical addresses */
 
-	/* Save the LBC LCS0 and LCS1 addresses for the DIU mux functions */
-	lbc_lcs0_ba = (void *)(get_lbc_br(0) & get_lbc_or(0) & 0xFFFF8000);
-	lbc_lcs1_ba = (void *)(get_lbc_br(1) & get_lbc_or(1) & 0xFFFF8000);
+	/*
+	 * Indirect mode requires both BR0 and BR1 to be set to "GPCM",
+	 * otherwise writes to these addresses won't actually appear on the
+	 * local bus, and so the PIXIS won't see them.
+	 *
+	 * In FCM mode, writes go to the NAND controller, which does not pass
+	 * them to the localbus directly.  So we force BR0 and BR1 into GPCM
+	 * mode, since we don't care about what's behind the localbus any
+	 * more.  However, we save those registers first, so that we can
+	 * restore them when necessary.
+	 */
+	new_br0 = old_br0 = get_lbc_br(0);
+	new_br1 = old_br1 = get_lbc_br(1);
+	new_or0 = old_or0 = get_lbc_or(0);
+	new_or1 = old_or1 = get_lbc_or(1);
+
+	/*
+	 * Use the existing BRx/ORx values if it's already GPCM. Otherwise,
+	 * force the values to simple 32KB GPCM windows with the most
+	 * conservative timing.
+	 */
+	if ((old_br0 & BR_MSEL) != BR_MS_GPCM) {
+		new_br0 = (get_lbc_br(0) & BR_BA) | BR_V;
+		new_or0 = OR_AM_32KB | 0xFF7;
+		set_lbc_br(0, new_br0);
+		set_lbc_or(0, new_or0);
+	}
+	if ((old_br1 & BR_MSEL) != BR_MS_GPCM) {
+		new_br1 = (get_lbc_br(1) & BR_BA) | BR_V;
+		new_or1 = OR_AM_32KB | 0xFF7;
+		set_lbc_br(1, new_br1);
+		set_lbc_or(1, new_or1);
+	}
+
+	/*
+	 * Determine the physical addresses for Chip Selects 0 and 1.  The
+	 * BR0/BR1 registers contain the truncated physical addresses for the
+	 * chip selects, mapped via the localbus LAW.  Since the BRx registers
+	 * only contain the lower 32 bits of the address, we have to determine
+	 * the upper 4 bits some other way.  The proper way is to scan the LAW
+	 * table looking for a matching localbus address. Instead, we cheat.
+	 * We know that the upper bits are 0 for 32-bit addressing, or 0xF for
+	 * 36-bit addressing.
+	 */
+#ifdef CONFIG_PHYS_64BIT
+	phys0 = 0xf00000000ULL | (old_br0 & old_or0 & BR_BA);
+	phys1 = 0xf00000000ULL | (old_br1 & old_or1 & BR_BA);
+#else
+	phys0 = old_br0 & old_or0 & BR_BA;
+	phys1 = old_br1 & old_or1 & BR_BA;
+#endif
+
+	 /* Save the LBC LCS0 and LCS1 addresses for the DIU mux functions */
+	lbc_lcs0_ba = map_physmem(phys0, 1, 0);
+	lbc_lcs1_ba = map_physmem(phys1, 1, 0);
 
 	pixel_format = cpu_to_le32(AD_BYTE_F | (3 << AD_ALPHA_C_SHIFT) |
 		(0 << AD_BLUE_C_SHIFT) | (1 << AD_GREEN_C_SHIFT) |
@@ -134,6 +189,7 @@ int platform_diu_init(unsigned int xres, unsigned int yres, const char *port)
 	out_8(lbc_lcs0_ba, offsetof(ngpixis_t, brdcfg0));
 	px_brdcfg0 = in_8(lbc_lcs1_ba);
 	out_8(lbc_lcs1_ba, px_brdcfg0 | PX_BRDCFG0_ELBC_DIU);
+	in_8(lbc_lcs1_ba);
 
 	/* Set PMUXCR to switch the muxed pins from the LBC to the DIU */
 	clrsetbits_be32(&gur->pmuxcr, PMUXCR_ELBCDIU_MASK, PMUXCR_ELBCDIU_DIU);
@@ -168,12 +224,10 @@ static int set_mux_to_lbc(void)
 		 * In DIU mode, the PIXIS can only be accessed indirectly
 		 * since we can't read/write the LBC directly.
 		 */
-
 		/* Set the board mux to LBC.  This will disable the display. */
 		out_8(lbc_lcs0_ba, offsetof(ngpixis_t, brdcfg0));
-		px_brdcfg0 = in_8(lbc_lcs1_ba);
-		out_8(lbc_lcs1_ba, (px_brdcfg0 & ~(PX_BRDCFG0_ELBC_SPI_MASK
-			| PX_BRDCFG0_ELBC_DIU)) | PX_BRDCFG0_ELBC_SPI_ELBC);
+		out_8(lbc_lcs1_ba, px_brdcfg0);
+		in_8(lbc_lcs1_ba);
 
 		/* Disable indirect PIXIS mode */
 		out_8(lbc_lcs0_ba, offsetof(ngpixis_t, csr));
@@ -184,6 +238,12 @@ static int set_mux_to_lbc(void)
 			 PMUXCR_ELBCDIU_NOR16);
 		in_be32(&gur->pmuxcr);
 
+		/* Restore the BR0 and BR1 settings */
+		set_lbc_br(0, old_br0);
+		set_lbc_or(0, old_or0);
+		set_lbc_br(1, old_br1);
+		set_lbc_or(1, old_or1);
+
 		return 1;
 	}
 
@@ -199,12 +259,18 @@ static void set_mux_to_diu(void)
 {
 	ccsr_gur_t *gur = (void *)CONFIG_SYS_MPC85xx_GUTS_ADDR;
 
+	/* Set BR0 and BR1 to GPCM mode */
+	set_lbc_br(0, new_br0);
+	set_lbc_or(0, new_or0);
+	set_lbc_br(1, new_br1);
+	set_lbc_or(1, new_or1);
+
 	/* Enable indirect PIXIS mode */
 	setbits_8(&pixis->csr, PX_CTL_ALTACC);
 
 	/* Set the board mux to DIU.  This will enable the display. */
 	out_8(lbc_lcs0_ba, offsetof(ngpixis_t, brdcfg0));
-	out_8(lbc_lcs1_ba, px_brdcfg0);
+	out_8(lbc_lcs1_ba, px_brdcfg0 | PX_BRDCFG0_ELBC_DIU);
 	in_8(lbc_lcs1_ba);
 
 	/* Set the chip mux to DIU mode. */
-- 
1.7.3.4