crypto: Add Qcom PRNG support

drivers/crypto/qcom-rng.c static int qcom_rng_probe(struct platform_device *pdev) · line 186

Quoted 10 lines · Vinod Koul

drivers/crypto/qcom-rng.c +10 -0

+	if (has_acpi_companion(&pdev->dev)) {
+		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);
+	}

There is a device_get_match_data() function, if you want to be consistent between ACPI and DT.

Meanwhile any word from testing on ACPI systems?

Quoted 1 line · Vinod

Meanwhile any word from testing on ACPI systems?

Jeff Hugo is handling that for me. Since it's a whole new API, he's had to start over.

Yes we can add driver data in ACPI ID as well so code can be:

         if (!has_acpi_companion(&pdev->dev)) {
                 rng->clk = devm_clk_get(&pdev->dev, "core");
                 if (IS_ERR(rng->clk))
                         return PTR_ERR(rng->clk);
         }
         rng->skip_init = device_get_match_data(&pdev->dev);

Looks much neater.

I will wait for feedback on other patches before updating this.

Quoted 9 lines · Vinod

Yes we can add driver data in ACPI ID as well so code can be:

         if (!has_acpi_companion(&pdev->dev)) {
                 rng->clk = devm_clk_get(&pdev->dev, "core");
                 if (IS_ERR(rng->clk))
                         return PTR_ERR(rng->clk);
         }
         rng->skip_init = device_get_match_data(&pdev->dev);

Quoted 1 line

Looks much neater.

Yeah, I like it.

Quoted 1 line

I will wait for feedback on other patches before updating this.

Jeff said it works, so I guess v5 will be good to go.

Quoted 14 lines · Timur Tabi

Quoted 10 lines · Vinod

Yes we can add driver data in ACPI ID as well so code can be:

          if (!has_acpi_companion(&pdev->dev)) {
                  rng->clk = devm_clk_get(&pdev->dev, "core");
                  if (IS_ERR(rng->clk))
                          return PTR_ERR(rng->clk);
          }
          rng->skip_init = device_get_match_data(&pdev->dev);

Looks much neater.

Yeah, I like it.

Quoted 3 lines

Quoted 1 line

I will wait for feedback on other patches before updating this.

Jeff said it works, so I guess v5 will be good to go.

Yes posting that right now. It would be great if you folks can test again on ACPI systems

Thanks

From: Timur Tabi <[email protected]>

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 <[email protected]>

[port to crypto API]

Signed-off-by Vinod Koul <[email protected]>

---
  drivers/crypto/qcom-rng.c | 30 ++++++++++++++++++++++++++----
  1 file changed, 26 insertions(+), 4 deletions(-)

drivers/crypto/qcom-rng.c +26 -4

index f1bd86acaf9d..385352e200db 100644
@@ -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>

@@ -168,11 +169,21 @@ 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,
+	 * and we should skip init
+	 */
+	if (has_acpi_companion(&pdev->dev)) {
+		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 +204,16 @@ 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, qcom_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 +227,7 @@ 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);