Commit 67fb1e29 authored by Uwe Kleine-König's avatar Uwe Kleine-König Committed by Herbert Xu
Browse files

hwrng: xgene - Simplify using devm_clk_get_optional_enabled() 



Instead of ignoring errors returned by devm_clk_get() and manually
enabling the clk for the whole lifetime of the bound device, use
devm_clk_get_optional_enabled(). This is simpler and also more correct
as it doesn't ignore errors. This is also more correct because now the
call to clk_disable_unprepare() can be dropped from xgene_rng_remove()
which happened while the hwrn device was still registered. With the devm
callback disabling the clk happens correctly only after
devm_hwrng_register() is undone.

As a result struct xgene_rng_dev::clk is only used in xgene_rng_probe, and
so the struct member can be replaced by a local variable.

Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 11f92a13

drivers/char/hw_random/xgene-rng.c

+6 −21
Original line number Diff line number Diff line
@@ -84,7 +84,6 @@ struct xgene_rng_dev { 
	unsigned long failure_ts;/* First failure timestamp */

	struct timer_list failure_timer;

	struct device *dev;

	struct clk *clk;

};



static void xgene_rng_expired_timer(struct timer_list *t)
@@ -314,6 +313,7 @@ static struct hwrng xgene_rng_func = { 
static int xgene_rng_probe(struct platform_device *pdev)

{

	struct xgene_rng_dev *ctx;

	struct clk *clk;

	int rc = 0;



	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
@@ -341,45 +341,30 @@ static int xgene_rng_probe(struct platform_device *pdev) 
		return dev_err_probe(&pdev->dev, rc, "Could not request RNG alarm IRQ\n");



	/* Enable IP clock */

	ctx->clk = devm_clk_get(&pdev->dev, NULL);

	if (IS_ERR(ctx->clk)) {

		dev_warn(&pdev->dev, "Couldn't get the clock for RNG\n");

	} else {

		rc = clk_prepare_enable(ctx->clk);

		if (rc)

			return dev_err_probe(&pdev->dev, rc,

					     "clock prepare enable failed for RNG");

	}

	clk = devm_clk_get_optional_enabled(&pdev->dev, NULL);

	if (IS_ERR(clk))

		return dev_err_probe(&pdev->dev, PTR_ERR(clk), "Couldn't get the clock for RNG\n");



	xgene_rng_func.priv = (unsigned long) ctx;



	rc = devm_hwrng_register(&pdev->dev, &xgene_rng_func);

	if (rc) {

		if (!IS_ERR(ctx->clk))

			clk_disable_unprepare(ctx->clk);

	if (rc)

		return dev_err_probe(&pdev->dev, rc, "RNG registering failed\n");

	}



	rc = device_init_wakeup(&pdev->dev, 1);

	if (rc) {

		if (!IS_ERR(ctx->clk))

			clk_disable_unprepare(ctx->clk);

	if (rc)

		return dev_err_probe(&pdev->dev, rc, "RNG device_init_wakeup failed\n");

	}



	return 0;

}



static int xgene_rng_remove(struct platform_device *pdev)

{

	struct xgene_rng_dev *ctx = platform_get_drvdata(pdev);

	int rc;



	rc = device_init_wakeup(&pdev->dev, 0);

	if (rc)

		dev_err(&pdev->dev, "RNG init wakeup failed error %d\n", rc);

	if (!IS_ERR(ctx->clk))

		clk_disable_unprepare(ctx->clk);



	return rc;

}