Messages in this thread | | | Subject | Re: [PATCH v3 6/6] crypto: qcom: Add ACPI support | From | Timur Tabi <> | Date | Tue, 3 Jul 2018 09:10:06 -0500 |
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On 7/3/18 1:04 AM, Vinod Koul wrote: > Add support for probing on ACPI systems, with ACPI HID QCOM8160. > > On ACPI systems, clocks are always enabled, the PRNG should > already be enabled, and the register region is read-only. > The driver only verifies that the hardware is already > enabled never tries to disable or configure it. > > Signed-off-by: Timur Tabi<timur@codeaurora.org> > [port to crypto API] > Signed-off-by: Vinod Koul<vkoul@kernel.org>
I've asked a colleague who still works at Qualcomm to test this code on silicon. It looks okay, but I just want to be sure.
> + /* > + * ACPI systems have v2 hardware. The clocks are always enabled, > + * the PRNG register space is read-only and the PRNG should > + * already be enabled. > + */ > + if (has_acpi_companion(&pdev->dev)) { > + val = readl(rng->base + PRNG_CONFIG); > + if (!(val & PRNG_CONFIG_HW_ENABLE)) { > + dev_err(&pdev->dev, "device is not enabled\n"); > + return -ENODEV; > + }
I'm having second thoughts about this PRNG_CONFIG_HW_ENABLE check. The PRNG on the QDF2400 is the same as the one on the 8996, so it should have the same register interface. Currently, the ACPI table points to a full PRNG register block, but I'm beginning to believe that it should instead point to a "reduced" block that doesn't have a PRNG_CONFIG register.
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