+
+#ifdef CONFIG_CFI_FLASH_USE_WEAK_ACCESSORS
+
+/*
+ * set_mux_to_lbc - disable the DIU so that we can read/write to elbc
+ *
+ * On the Freescale P1022, the DIU video signal and the LBC address/data lines
+ * share the same pins, which means that when the DIU is active (e.g. the
+ * console is on the DVI display), NOR flash cannot be accessed. So we use the
+ * weak accessor feature of the CFI flash code to temporarily switch the pin
+ * mux from DIU to LBC whenever we want to read or write flash. This has a
+ * significant performance penalty, but it's the only way to make it work.
+ *
+ * There are two muxes: one on the chip, and one on the board. The chip mux
+ * controls whether the pins are used for the DIU or the LBC, and it is
+ * set via PMUXCR. The board mux controls whether those signals go to
+ * the video connector or the NOR flash chips, and it is set via the ngPIXIS.
+ */
+static int set_mux_to_lbc(void)
+{
+ ccsr_gur_t *gur = (void *)CONFIG_SYS_MPC85xx_GUTS_ADDR;
+
+ /* Switch the muxes only if they're currently set to DIU mode */
+ if ((in_be32(&gur->pmuxcr) & PMUXCR_ELBCDIU_MASK) ==
+ PMUXCR_ELBCDIU_NOR16) {
+ /*
+ * 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);
+
+ /* Disable indirect PIXIS mode */
+ out_8(lbc_lcs0_ba, offsetof(ngpixis_t, csr));
+ clrbits_8(lbc_lcs1_ba, PX_CTL_ALTACC);
+
+ /* Set the chip mux to LBC mode, so that writes go to flash. */
+ out_be32(&gur->pmuxcr, (pmuxcr & ~PMUXCR_ELBCDIU_MASK) |
+ PMUXCR_ELBCDIU_NOR16);
+ in_be32(&gur->pmuxcr);
+
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * set_mux_to_diu - re-enable the DIU muxing
+ *
+ * This function restores the chip and board muxing to point to the DIU.
+ */
+static void set_mux_to_diu(void)
+{
+ ccsr_gur_t *gur = (void *)CONFIG_SYS_MPC85xx_GUTS_ADDR;
+
+ /* 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);
+ in_8(lbc_lcs1_ba);
+
+ /* Set the chip mux to DIU mode. */
+ out_be32(&gur->pmuxcr, pmuxcr);
+ in_be32(&gur->pmuxcr);
+}
+
+void flash_write8(u8 value, void *addr)
+{
+ int sw = set_mux_to_lbc();
+
+ __raw_writeb(value, addr);
+ if (sw)
+ set_mux_to_diu();
+}
+
+void flash_write16(u16 value, void *addr)
+{
+ int sw = set_mux_to_lbc();
+
+ __raw_writew(value, addr);
+ if (sw)
+ set_mux_to_diu();
+}
+
+void flash_write32(u32 value, void *addr)
+{
+ int sw = set_mux_to_lbc();
+
+ __raw_writel(value, addr);
+ if (sw)
+ set_mux_to_diu();
+}
+
+void flash_write64(u64 value, void *addr)
+{
+ int sw = set_mux_to_lbc();
+
+ /* There is no __raw_writeq(), so do the write manually */
+ *(volatile u64 *)addr = value;
+ if (sw)
+ set_mux_to_diu();
+}
+
+u8 flash_read8(void *addr)
+{
+ u8 ret;
+
+ int sw = set_mux_to_lbc();
+
+ ret = __raw_readb(addr);
+ if (sw)
+ set_mux_to_diu();
+
+ return ret;
+}
+
+u16 flash_read16(void *addr)
+{
+ u16 ret;
+
+ int sw = set_mux_to_lbc();
+
+ ret = __raw_readw(addr);
+ if (sw)
+ set_mux_to_diu();
+
+ return ret;
+}
+
+u32 flash_read32(void *addr)
+{
+ u32 ret;
+
+ int sw = set_mux_to_lbc();
+
+ ret = __raw_readl(addr);
+ if (sw)
+ set_mux_to_diu();
+
+ return ret;
+}
+
+u64 flash_read64(void *addr)
+{
+ u64 ret;
+
+ int sw = set_mux_to_lbc();
+
+ /* There is no __raw_readq(), so do the read manually */
+ ret = *(volatile u64 *)addr;
+ if (sw)
+ set_mux_to_diu();
+
+ return ret;
+}
+
+#endif