From 00f7bbae92e3b13f2b37aeb1def9bb12445521b7 Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Thu, 2 Oct 2008 19:17:33 +0400 Subject: mpc83xx: fix PCI scan hang on the standalone MPC837xE-MDS boards The MPC837xE-MDS board's CPLD can auto-detect if the board is on the PIB, standalone or acting as a PCI agent. User's Guide says: - When the CPLD recognizes its location on the PIB it automatically configures RCW to the PCI Host. - If the CPLD fails to recognize its location then it is automatically configured as an Agent and the PCI is configured to an external arbiter. This sounds good. Though in the standalone setup the CPLD sets PCI_HOST flag (it's ok, we can't act as PCI agents since we receive CLKIN, not PCICLK), but the CPLD doesn't set the ARBITER_ENABLE flag, and without any arbiter bad things will happen (here the board hangs during any config space reads). In this situation we must disable the PCI. And in case of anybody really want to use an external arbiter, we provide "pci_external_aribter" environment variable. Signed-off-by: Anton Vorontsov Signed-off-by: Kim Phillips --- board/freescale/mpc837xemds/mpc837xemds.c | 41 +++++++++++++++++++++++++++++++ board/freescale/mpc837xemds/pci.c | 3 +++ 2 files changed, 44 insertions(+) (limited to 'board/freescale') diff --git a/board/freescale/mpc837xemds/mpc837xemds.c b/board/freescale/mpc837xemds/mpc837xemds.c index f4bdb89914..49afa7cf84 100644 --- a/board/freescale/mpc837xemds/mpc837xemds.c +++ b/board/freescale/mpc837xemds/mpc837xemds.c @@ -270,6 +270,45 @@ int checkboard(void) return 0; } +#ifdef CONFIG_PCI +int board_pci_host_broken(void) +{ + struct immap __iomem *im = (struct immap __iomem *)CONFIG_SYS_IMMR; + const u32 rcw_mask = HRCWH_PCI1_ARBITER_ENABLE | HRCWH_PCI_HOST; + const char *pci_ea = getenv("pci_external_arbiter"); + + /* It's always OK in case of external arbiter. */ + if (pci_ea && !strcmp(pci_ea, "yes")) + return 0; + + if ((in_be32(&im->reset.rcwh) & rcw_mask) != rcw_mask) + return 1; + + return 0; +} + +static void ft_pci_fixup(void *blob, bd_t *bd) +{ + const char *status = "broken (no arbiter)"; + int off; + int err; + + off = fdt_path_offset(blob, "pci0"); + if (off < 0) { + printf("WARNING: could not find pci0 alias: %s.\n", + fdt_strerror(off)); + return; + } + + err = fdt_setprop(blob, off, "status", status, strlen(status) + 1); + if (err) { + printf("WARNING: could not set status for pci0: %s.\n", + fdt_strerror(err)); + return; + } +} +#endif + #if defined(CONFIG_OF_BOARD_SETUP) void ft_board_setup(void *blob, bd_t *bd) { @@ -277,6 +316,8 @@ void ft_board_setup(void *blob, bd_t *bd) ft_tsec_fixup(blob, bd); #ifdef CONFIG_PCI ft_pci_setup(blob, bd); + if (board_pci_host_broken()) + ft_pci_fixup(blob, bd); #endif } #endif /* CONFIG_OF_BOARD_SETUP */ diff --git a/board/freescale/mpc837xemds/pci.c b/board/freescale/mpc837xemds/pci.c index 24cc130148..df4e748e97 100644 --- a/board/freescale/mpc837xemds/pci.c +++ b/board/freescale/mpc837xemds/pci.c @@ -47,6 +47,9 @@ void pci_init_board(void) volatile law83xx_t *pci_law = immr->sysconf.pcilaw; struct pci_region *reg[] = { pci_regions }; + if (board_pci_host_broken()) + return; + /* Enable all 5 PCI_CLK_OUTPUTS */ clk->occr |= 0xf8000000; udelay(2000); -- cgit v1.2.1