[PATCH 0/4] hwrng: pic32 - some simple cleanups

[PATCH 0/4] hwrng: pic32 - some simple cleanups

[Martin Kaiser]

Here's a series with simple clenaups to the pic32 driver. The patches were
compile tested only.

Martin Kaiser (4):
  hwrng: pic32 - enable compile-testing
  hwrng: pic32 - use devm_clk_get_enabled
  hwrng: pic32 - remove unused defines
  hwrng: pic32 - enable TRNG only while it's used

 drivers/char/hw_random/Kconfig     |  2 +-
 drivers/char/hw_random/pic32-rng.c | 71 +++++++++++-------------------
 2 files changed, 27 insertions(+), 46 deletions(-)

-- 
2.30.2

[PATCH 1/4] hwrng: pic32 - enable compile-testing

[Martin Kaiser]

Enable compile testing for the pic32 driver.

Remove the dependency on HW_RANDOM. The pic32 config section is under
"if HW_RANDOM".

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

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index e0b3786ca51b..1aeba12391a1 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -385,7 +385,7 @@ config HW_RANDOM_STM32
 
 config HW_RANDOM_PIC32
 	tristate "Microchip PIC32 Random Number Generator support"
-	depends on HW_RANDOM && MACH_PIC32
+	depends on MACH_PIC32 || COMPILE_TEST
 	default y
 	help
 	  This driver provides kernel-side support for the Random Number
-- 
2.30.2

[PATCH 2/4] hwrng: pic32 - use devm_clk_get_enabled

[Martin Kaiser]

Use devm_clk_get_enabled in the pic32 driver. Ensure that the clock is
enabled as long as the driver is registered with the hwrng core.

Fixes: 7ea39973d1e5 ("hwrng: pic32 - Use device-managed registration API")
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
---
 drivers/char/hw_random/pic32-rng.c | 19 +++++--------------
 1 file changed, 5 insertions(+), 14 deletions(-)

diff --git a/drivers/char/hw_random/pic32-rng.c b/drivers/char/hw_random/pic32-rng.c
index 99c8bd0859a1..e04a054e8930 100644
--- a/drivers/char/hw_random/pic32-rng.c
+++ b/drivers/char/hw_random/pic32-rng.c
@@ -36,7 +36,6 @@
 struct pic32_rng {
 	void __iomem	*base;
 	struct hwrng	rng;
-	struct clk	*clk;
 };
 
 /*
@@ -70,6 +69,7 @@ static int pic32_rng_read(struct hwrng *rng, void *buf, size_t max,
 static int pic32_rng_probe(struct platform_device *pdev)
 {
 	struct pic32_rng *priv;
+	struct clk *clk;
 	u32 v;
 	int ret;
 
@@ -81,13 +81,9 @@ static int pic32_rng_probe(struct platform_device *pdev)
 	if (IS_ERR(priv->base))
 		return PTR_ERR(priv->base);
 
-	priv->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(priv->clk))
-		return PTR_ERR(priv->clk);
-
-	ret = clk_prepare_enable(priv->clk);
-	if (ret)
-		return ret;
+	clk = devm_clk_get_enabled(&pdev->dev, NULL);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
 
 	/* enable TRNG in enhanced mode */
 	v = TRNGEN | TRNGMOD;
@@ -98,15 +94,11 @@ static int pic32_rng_probe(struct platform_device *pdev)
 
 	ret = devm_hwrng_register(&pdev->dev, &priv->rng);
 	if (ret)
-		goto err_register;
+		return ret;
 
 	platform_set_drvdata(pdev, priv);
 
 	return 0;
-
-err_register:
-	clk_disable_unprepare(priv->clk);
-	return ret;
 }
 
 static int pic32_rng_remove(struct platform_device *pdev)
@@ -114,7 +106,6 @@ static int pic32_rng_remove(struct platform_device *pdev)
 	struct pic32_rng *rng = platform_get_drvdata(pdev);
 
 	writel(0, rng->base + RNGCON);
-	clk_disable_unprepare(rng->clk);
 	return 0;
 }
 
-- 
2.30.2

[PATCH 3/4] hwrng: pic32 - remove unused defines

[Martin Kaiser]

Remove some unused defines and fix the indentation.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
---
 drivers/char/hw_random/pic32-rng.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/drivers/char/hw_random/pic32-rng.c b/drivers/char/hw_random/pic32-rng.c
index e04a054e8930..c1b3f5915f03 100644
--- a/drivers/char/hw_random/pic32-rng.c
+++ b/drivers/char/hw_random/pic32-rng.c
@@ -19,19 +19,12 @@
 #include <linux/slab.h>
 
 #define RNGCON		0x04
-#define  TRNGEN		BIT(8)
-#define  PRNGEN		BIT(9)
-#define  PRNGCONT	BIT(10)
-#define  TRNGMOD	BIT(11)
-#define  SEEDLOAD	BIT(12)
-#define RNGPOLY1	0x08
-#define RNGPOLY2	0x0C
-#define RNGNUMGEN1	0x10
-#define RNGNUMGEN2	0x14
+#define TRNGEN		BIT(8)
+#define TRNGMOD		BIT(11)
 #define RNGSEED1	0x18
 #define RNGSEED2	0x1C
 #define RNGRCNT		0x20
-#define  RCNT_MASK	0x7F
+#define RCNT_MASK	0x7F
 
 struct pic32_rng {
 	void __iomem	*base;
-- 
2.30.2

[PATCH 4/4] hwrng: pic32 - enable TRNG only while it's used

[Martin Kaiser]

The probe function enables the TRNG hardware before registering the
driver. If registration fails, probe returns an error, but the TRNG
remains enabled.

Define init and cleanup functions, enable and disable the hardware there.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
---
 drivers/char/hw_random/pic32-rng.c | 41 ++++++++++++++----------------
 1 file changed, 19 insertions(+), 22 deletions(-)

diff --git a/drivers/char/hw_random/pic32-rng.c b/drivers/char/hw_random/pic32-rng.c
index c1b3f5915f03..1902f4389a3f 100644
--- a/drivers/char/hw_random/pic32-rng.c
+++ b/drivers/char/hw_random/pic32-rng.c
@@ -38,6 +38,15 @@ struct pic32_rng {
  */
 #define RNG_TIMEOUT 500
 
+static int pic32_rng_init(struct hwrng *rng)
+{
+	struct pic32_rng *priv = container_of(rng, struct pic32_rng, rng);
+
+	/* enable TRNG in enhanced mode */
+	writel(TRNGEN | TRNGMOD, priv->base + RNGCON);
+	return 0;
+}
+
 static int pic32_rng_read(struct hwrng *rng, void *buf, size_t max,
 			  bool wait)
 {
@@ -59,12 +68,17 @@ static int pic32_rng_read(struct hwrng *rng, void *buf, size_t max,
 	return -EIO;
 }
 
+static void pic32_rng_cleanup(struct hwrng *rng)
+{
+	struct pic32_rng *priv = container_of(rng, struct pic32_rng, rng);
+
+	writel(0, priv->base + RNGCON);
+}
+
 static int pic32_rng_probe(struct platform_device *pdev)
 {
 	struct pic32_rng *priv;
 	struct clk *clk;
-	u32 v;
-	int ret;
 
 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
@@ -78,28 +92,12 @@ static int pic32_rng_probe(struct platform_device *pdev)
 	if (IS_ERR(clk))
 		return PTR_ERR(clk);
 
-	/* enable TRNG in enhanced mode */
-	v = TRNGEN | TRNGMOD;
-	writel(v, priv->base + RNGCON);
-
 	priv->rng.name = pdev->name;
+	priv->rng.init = pic32_rng_init;
 	priv->rng.read = pic32_rng_read;
+	priv->rng.cleanup = pic32_rng_cleanup;
 
-	ret = devm_hwrng_register(&pdev->dev, &priv->rng);
-	if (ret)
-		return ret;
-
-	platform_set_drvdata(pdev, priv);
-
-	return 0;
-}
-
-static int pic32_rng_remove(struct platform_device *pdev)
-{
-	struct pic32_rng *rng = platform_get_drvdata(pdev);
-
-	writel(0, rng->base + RNGCON);
-	return 0;
+	return devm_hwrng_register(&pdev->dev, &priv->rng);
 }
 
 static const struct of_device_id pic32_rng_of_match[] __maybe_unused = {
@@ -110,7 +108,6 @@ MODULE_DEVICE_TABLE(of, pic32_rng_of_match);
 
 static struct platform_driver pic32_rng_driver = {
 	.probe		= pic32_rng_probe,
-	.remove		= pic32_rng_remove,
 	.driver		= {
 		.name	= "pic32-rng",
 		.of_match_table = of_match_ptr(pic32_rng_of_match),
-- 
2.30.2

Re: [PATCH 0/4] hwrng: pic32 - some simple cleanups

[Herbert Xu]

On Tue, Jul 04, 2023 at 07:31:59PM +0200, Martin Kaiser wrote:
> Here's a series with simple clenaups to the pic32 driver. The patches were
> compile tested only.
> 
> Martin Kaiser (4):
>   hwrng: pic32 - enable compile-testing
>   hwrng: pic32 - use devm_clk_get_enabled
>   hwrng: pic32 - remove unused defines
>   hwrng: pic32 - enable TRNG only while it's used
> 
>  drivers/char/hw_random/Kconfig     |  2 +-
>  drivers/char/hw_random/pic32-rng.c | 71 +++++++++++-------------------
>  2 files changed, 27 insertions(+), 46 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