From 1c96bee4df1998b9dec3e2ef8f77e8436e29342b Mon Sep 17 00:00:00 2001 From: Sekhar Nori Date: Thu, 18 Feb 2016 16:49:56 +0530 Subject: [PATCH] ARM: DRA7: hwmod: Add custom reset handler for PCIeSS Add a custom reset handler for DRA7x PCIeSS. This handler is required to deassert PCIe hardreset lines after they have been asserted. This enables the PCIe driver to access registers after PCIeSS has been runtime enabled without having to deassert hardreset lines itself. With this patch applied, used lspci to make sure connected PCIe device enumerates on DRA74x and DRA72x EVMs. Signed-off-by: Sekhar Nori Reported-by: Richard Cochran Tested-by: Kishon Vijay Abraham I Cc: Suman Anna Cc: Dave Gerlach Cc: Tony Lindgren Cc: Bjorn Helgaas Cc: Russell King Signed-off-by: Paul Walmsley --- arch/arm/mach-omap2/omap_hwmod_7xx_data.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/arch/arm/mach-omap2/omap_hwmod_7xx_data.c b/arch/arm/mach-omap2/omap_hwmod_7xx_data.c index b61355e2a771..252b74633e31 100644 --- a/arch/arm/mach-omap2/omap_hwmod_7xx_data.c +++ b/arch/arm/mach-omap2/omap_hwmod_7xx_data.c @@ -1526,8 +1526,31 @@ static struct omap_hwmod dra7xx_ocp2scp3_hwmod = { * */ +/* + * As noted in documentation for _reset() in omap_hwmod.c, the stock reset + * functionality of OMAP HWMOD layer does not deassert the hardreset lines + * associated with an IP automatically leaving the driver to handle that + * by itself. This does not work for PCIeSS which needs the reset lines + * deasserted for the driver to start accessing registers. + * + * We use a PCIeSS HWMOD class specific reset handler to deassert the hardreset + * lines after asserting them. + */ +static int dra7xx_pciess_reset(struct omap_hwmod *oh) +{ + int i; + + for (i = 0; i < oh->rst_lines_cnt; i++) { + omap_hwmod_assert_hardreset(oh, oh->rst_lines[i].name); + omap_hwmod_deassert_hardreset(oh, oh->rst_lines[i].name); + } + + return 0; +} + static struct omap_hwmod_class dra7xx_pciess_hwmod_class = { .name = "pcie", + .reset = dra7xx_pciess_reset, }; /* pcie1 */ -- GitLab