hwrng: ingenic: simplify the code

hwrng: ingenic: simplify the code

[Martin Kaiser]

Simplify the ingenic-trng driver a bit. Switch to devm_clk_get_enabled and
devm_hwrng_register. Remove some unused code.

The changes were compile-tested only (I don't have this hardware).

Martin Kaiser (7):
  hwrng: ingenic - enable compile testing
  hwrng: ingenic - remove two unused defines
  hwrng: ingenic - remove dead assignments
  hwrng: ingenic - use devm_clk_get_enabled
  hwrng: ingenic - use dev_err_probe in error paths
  hwrng: ingenic - don't disable the rng in ingenic_trng_remove
  hwrng: ingenic - switch to device managed registration

 drivers/char/hw_random/Kconfig        |  3 +-
 drivers/char/hw_random/ingenic-trng.c | 57 ++++++---------------------
 2 files changed, 12 insertions(+), 48 deletions(-)

-- 
2.30.2


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[PATCH 1/7] hwrng: ingenic - enable compile testing

[Martin Kaiser]

Enable compile testing for the ingenic-trng driver.

Remove the dependency on HW_RANDOM. The ingenic-trng config section is
under "if HW_RANDOM".

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
---
 drivers/char/hw_random/Kconfig | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 1aeba12391a1..5d72b8da3c36 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -271,8 +271,7 @@ config HW_RANDOM_INGENIC_RNG
 
 config HW_RANDOM_INGENIC_TRNG
 	tristate "Ingenic True Random Number Generator support"
-	depends on HW_RANDOM
-	depends on MACH_X1830
+	depends on MACH_X1830 || COMPILE_TEST
 	default HW_RANDOM
 	help
 	  This driver provides kernel-side support for the True Random Number Generator
-- 
2.30.2


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[PATCH 2/7] hwrng: ingenic - remove two unused defines

[Martin Kaiser]

Remove two defines which are not used in the ingenic-trng driver's code.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
---
 drivers/char/hw_random/ingenic-trng.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/char/hw_random/ingenic-trng.c b/drivers/char/hw_random/ingenic-trng.c
index 0eb80f786f4d..64286cbdf158 100644
--- a/drivers/char/hw_random/ingenic-trng.c
+++ b/drivers/char/hw_random/ingenic-trng.c
@@ -22,8 +22,6 @@
 #define TRNG_REG_STATUS_OFFSET		0x08
 
 /* bits within the CFG register */
-#define CFG_RDY_CLR					BIT(12)
-#define CFG_INT_MASK				BIT(11)
 #define CFG_GEN_EN					BIT(0)
 
 /* bits within the STATUS register */
-- 
2.30.2


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[PATCH 3/7] hwrng: ingenic - remove dead assignments

[Martin Kaiser]

Don't assign a value to ret if we're about to return from the probe
function and ret's value is not used.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
---
 drivers/char/hw_random/ingenic-trng.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/char/hw_random/ingenic-trng.c b/drivers/char/hw_random/ingenic-trng.c
index 64286cbdf158..bfec28ceab00 100644
--- a/drivers/char/hw_random/ingenic-trng.c
+++ b/drivers/char/hw_random/ingenic-trng.c
@@ -86,13 +86,11 @@ static int ingenic_trng_probe(struct platform_device *pdev)
 	trng->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(trng->base)) {
 		pr_err("%s: Failed to map DTRNG registers\n", __func__);
-		ret = PTR_ERR(trng->base);
 		return PTR_ERR(trng->base);
 	}
 
 	trng->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(trng->clk)) {
-		ret = PTR_ERR(trng->clk);
 		pr_crit("%s: Cannot get DTRNG clock\n", __func__);
 		return PTR_ERR(trng->clk);
 	}
-- 
2.30.2


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[PATCH 4/7] hwrng: ingenic - use devm_clk_get_enabled

[Martin Kaiser]

Use devm_clk_get_enabled in the ingenic-trng driver. We don't have to
disable and unprepare the clock any more in error paths or in the remove
function.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
---
 drivers/char/hw_random/ingenic-trng.c | 24 ++++++------------------
 1 file changed, 6 insertions(+), 18 deletions(-)

diff --git a/drivers/char/hw_random/ingenic-trng.c b/drivers/char/hw_random/ingenic-trng.c
index bfec28ceab00..906fa78de47e 100644
--- a/drivers/char/hw_random/ingenic-trng.c
+++ b/drivers/char/hw_random/ingenic-trng.c
@@ -29,7 +29,6 @@
 
 struct ingenic_trng {
 	void __iomem *base;
-	struct clk *clk;
 	struct hwrng rng;
 };
 
@@ -77,6 +76,7 @@ static int ingenic_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait
 static int ingenic_trng_probe(struct platform_device *pdev)
 {
 	struct ingenic_trng *trng;
+	struct clk *clk;
 	int ret;
 
 	trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);
@@ -89,16 +89,10 @@ static int ingenic_trng_probe(struct platform_device *pdev)
 		return PTR_ERR(trng->base);
 	}
 
-	trng->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(trng->clk)) {
-		pr_crit("%s: Cannot get DTRNG clock\n", __func__);
-		return PTR_ERR(trng->clk);
-	}
-
-	ret = clk_prepare_enable(trng->clk);
-	if (ret) {
-		pr_crit("%s: Unable to enable DTRNG clock\n", __func__);
-		return ret;
+	clk = devm_clk_get_enabled(&pdev->dev, NULL);
+	if (IS_ERR(clk)) {
+		pr_crit("%s: Cannot get and enable DTRNG clock\n", __func__);
+		return PTR_ERR(clk);
 	}
 
 	trng->rng.name = pdev->name;
@@ -109,17 +103,13 @@ static int ingenic_trng_probe(struct platform_device *pdev)
 	ret = hwrng_register(&trng->rng);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to register hwrng\n");
-		goto err_unprepare_clk;
+		return ret;
 	}
 
 	platform_set_drvdata(pdev, trng);
 
 	dev_info(&pdev->dev, "Ingenic DTRNG driver registered\n");
 	return 0;
-
-err_unprepare_clk:
-	clk_disable_unprepare(trng->clk);
-	return ret;
 }
 
 static int ingenic_trng_remove(struct platform_device *pdev)
@@ -133,8 +123,6 @@ static int ingenic_trng_remove(struct platform_device *pdev)
 	ctrl &= ~CFG_GEN_EN;
 	writel(ctrl, trng->base + TRNG_REG_CFG_OFFSET);
 
-	clk_disable_unprepare(trng->clk);
-
 	return 0;
 }
 
-- 
2.30.2


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[PATCH 5/7] hwrng: ingenic - use dev_err_probe in error paths

[Martin Kaiser]

Use dev_err_probe in error paths to make the code a bit shorter.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
---
 drivers/char/hw_random/ingenic-trng.c | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/char/hw_random/ingenic-trng.c b/drivers/char/hw_random/ingenic-trng.c
index 906fa78de47e..cc88a941c929 100644
--- a/drivers/char/hw_random/ingenic-trng.c
+++ b/drivers/char/hw_random/ingenic-trng.c
@@ -84,16 +84,14 @@ static int ingenic_trng_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	trng->base = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(trng->base)) {
-		pr_err("%s: Failed to map DTRNG registers\n", __func__);
-		return PTR_ERR(trng->base);
-	}
+	if (IS_ERR(trng->base))
+		return dev_err_probe(&pdev->dev, PTR_ERR(trng->base),
+				     "%s: Failed to map DTRNG registers\n", __func__);
 
 	clk = devm_clk_get_enabled(&pdev->dev, NULL);
-	if (IS_ERR(clk)) {
-		pr_crit("%s: Cannot get and enable DTRNG clock\n", __func__);
-		return PTR_ERR(clk);
-	}
+	if (IS_ERR(clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(clk),
+				     "%s: Cannot get and enable DTRNG clock\n", __func__);
 
 	trng->rng.name = pdev->name;
 	trng->rng.init = ingenic_trng_init;
@@ -101,10 +99,8 @@ static int ingenic_trng_probe(struct platform_device *pdev)
 	trng->rng.read = ingenic_trng_read;
 
 	ret = hwrng_register(&trng->rng);
-	if (ret) {
-		dev_err(&pdev->dev, "Failed to register hwrng\n");
-		return ret;
-	}
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret, "Failed to register hwrng\n");
 
 	platform_set_drvdata(pdev, trng);
 
-- 
2.30.2


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[PATCH 6/7] hwrng: ingenic - don't disable the rng in ingenic_trng_remove

[Martin Kaiser]

There's no need to disable the rng in ingenic_trng_remove.

The driver's init function sets the CFG_GEN_EN bit to enable the
rng. The cleanup function clears CFG_GEN_EN to revert this.

The remove function calls hwrng_unregister. If the ingenic-trng is not
the current rng at this point, CFG_GEN_EN has already been cleared. If
the ingenic-trng is the current rng, drop_current_rng will call the
cleanup function.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
---
 drivers/char/hw_random/ingenic-trng.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/char/hw_random/ingenic-trng.c b/drivers/char/hw_random/ingenic-trng.c
index cc88a941c929..9c54721f8399 100644
--- a/drivers/char/hw_random/ingenic-trng.c
+++ b/drivers/char/hw_random/ingenic-trng.c
@@ -111,14 +111,9 @@ static int ingenic_trng_probe(struct platform_device *pdev)
 static int ingenic_trng_remove(struct platform_device *pdev)
 {
 	struct ingenic_trng *trng = platform_get_drvdata(pdev);
-	unsigned int ctrl;
 
 	hwrng_unregister(&trng->rng);
 
-	ctrl = readl(trng->base + TRNG_REG_CFG_OFFSET);
-	ctrl &= ~CFG_GEN_EN;
-	writel(ctrl, trng->base + TRNG_REG_CFG_OFFSET);
-
 	return 0;
 }
 
-- 
2.30.2


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[PATCH 7/7] hwrng: ingenic - switch to device managed registration

[Martin Kaiser]

Call devm_hwrng_register for device managed registration of the
ingenic-trng driver. ingenic_trng_remove can then be deleted.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
---
 drivers/char/hw_random/ingenic-trng.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/drivers/char/hw_random/ingenic-trng.c b/drivers/char/hw_random/ingenic-trng.c
index 9c54721f8399..3967a8dbe967 100644
--- a/drivers/char/hw_random/ingenic-trng.c
+++ b/drivers/char/hw_random/ingenic-trng.c
@@ -98,7 +98,7 @@ static int ingenic_trng_probe(struct platform_device *pdev)
 	trng->rng.cleanup = ingenic_trng_cleanup;
 	trng->rng.read = ingenic_trng_read;
 
-	ret = hwrng_register(&trng->rng);
+	ret = devm_hwrng_register(&pdev->dev, &trng->rng);
 	if (ret)
 		return dev_err_probe(&pdev->dev, ret, "Failed to register hwrng\n");
 
@@ -108,15 +108,6 @@ static int ingenic_trng_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int ingenic_trng_remove(struct platform_device *pdev)
-{
-	struct ingenic_trng *trng = platform_get_drvdata(pdev);
-
-	hwrng_unregister(&trng->rng);
-
-	return 0;
-}
-
 static const struct of_device_id ingenic_trng_of_match[] = {
 	{ .compatible = "ingenic,x1830-dtrng" },
 	{ /* sentinel */ }
@@ -125,7 +116,6 @@ MODULE_DEVICE_TABLE(of, ingenic_trng_of_match);
 
 static struct platform_driver ingenic_trng_driver = {
 	.probe		= ingenic_trng_probe,
-	.remove		= ingenic_trng_remove,
 	.driver		= {
 		.name	= "ingenic-trng",
 		.of_match_table = ingenic_trng_of_match,
-- 
2.30.2


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Re: hwrng: ingenic: simplify the code

[Herbert Xu]

On Mon, Jul 10, 2023 at 10:27:26PM +0200, Martin Kaiser wrote:
> Simplify the ingenic-trng driver a bit. Switch to devm_clk_get_enabled and
> devm_hwrng_register. Remove some unused code.
> 
> The changes were compile-tested only (I don't have this hardware).
> 
> Martin Kaiser (7):
>   hwrng: ingenic - enable compile testing
>   hwrng: ingenic - remove two unused defines
>   hwrng: ingenic - remove dead assignments
>   hwrng: ingenic - use devm_clk_get_enabled
>   hwrng: ingenic - use dev_err_probe in error paths
>   hwrng: ingenic - don't disable the rng in ingenic_trng_remove
>   hwrng: ingenic - switch to device managed registration
> 
>  drivers/char/hw_random/Kconfig        |  3 +-
>  drivers/char/hw_random/ingenic-trng.c | 57 ++++++---------------------
>  2 files changed, 12 insertions(+), 48 deletions(-)
> 
> -- 
> 2.30.2

All applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

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