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SubjectRe: [PATCH v3 3/3] pci: dra7xx: use pdata callbacks to perform reset
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Hi,

On Tuesday 01 March 2016 01:55 PM, Paul Walmsley wrote:
>
> Folks, the following is what I've queued for this.

Thanks Paul.

Bjorn,

With this patch merged, enabling pci-dra7xx won't result in system freeze
anymore. I can send a patch to revert depends on BROKEN.

Thanks
Kishon

>
>
> - Paul
>
>
> From: Sekhar Nori <nsekhar@ti.com>
> 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 <nsekhar@ti.com>
> Reported-by: Richard Cochran <richardcochran@gmail.com>
> Tested-by: Kishon Vijay Abraham I <kishon@ti.com>
> Cc: Suman Anna <s-anna@ti.com>
> Cc: Dave Gerlach <d-gerlach@ti.com>
> Cc: Tony Lindgren <tony@atomide.com>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Russell King <linux@arm.linux.org.uk>
> Signed-off-by: Paul Walmsley <paul@pwsan.com>
> ---
> 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 */
>

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