From: Timur Tabi <timur@xxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxx> [port to crypto API] Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx> --- drivers/crypto/qcom-rng.c | 37 +++++++++++++++++++++++++++++++++---- 1 file changed, 33 insertions(+), 4 deletions(-) diff --git a/drivers/crypto/qcom-rng.c b/drivers/crypto/qcom-rng.c index fdbbcac7bcb8..bc0131d130d6 100644 --- a/drivers/crypto/qcom-rng.c +++ b/drivers/crypto/qcom-rng.c @@ -4,6 +4,7 @@ // Based on msm-rng.c and downstream driver #include <crypto/internal/rng.h> +#include <linux/acpi.h> #include <linux/clk.h> #include <linux/crypto.h> #include <linux/module.h> @@ -154,6 +155,7 @@ static int qcom_rng_probe(struct platform_device *pdev) { struct resource *res; struct qcom_rng *rng; + u32 val; int ret; rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL); @@ -168,11 +170,27 @@ static int qcom_rng_probe(struct platform_device *pdev) if (IS_ERR(rng->base)) return PTR_ERR(rng->base); - rng->clk = devm_clk_get(&pdev->dev, "core"); - if (IS_ERR(rng->clk)) - return PTR_ERR(rng->clk); - rng->skip_init = (unsigned long)of_device_get_match_data(&pdev->dev); + /* + * 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; + } + rng->skip_init = 1; + } else { + rng->clk = devm_clk_get(&pdev->dev, "core"); + if (IS_ERR(rng->clk)) + return PTR_ERR(rng->clk); + + rng->skip_init = + (unsigned long)of_device_get_match_data(&pdev->dev); + } qcom_rng_dev = rng; ret = crypto_register_rng(&qcom_rng_alg); @@ -193,6 +211,16 @@ static int qcom_rng_remove(struct platform_device *pdev) return 0; } +#if IS_ENABLED(CONFIG_ACPI) +static const struct acpi_device_id qcom_rng_acpi_match[] = { + { + .id = "QCOM8160", + }, + {} +}; +MODULE_DEVICE_TABLE(acpi, msm_rng_acpi_match); +#endif + static const struct of_device_id qcom_rng_of_match[] = { { .compatible = "qcom,prng", .data = (void *)0}, { .compatible = "qcom,prng-ee", .data = (void *)1}, @@ -206,6 +234,7 @@ static struct platform_driver qcom_rng_driver = { .driver = { .name = KBUILD_MODNAME, .of_match_table = of_match_ptr(qcom_rng_of_match), + .acpi_match_table = ACPI_PTR(qcom_rng_acpi_match), } }; module_platform_driver(qcom_rng_driver); -- 2.14.4