[PATCH v7 0/6] clk: provide new devm helpers for prepared and enabled clocks

STALE1873d

Revision v7 of 9 in this series.

7 messages, 2 authors, 2021-05-24 · open the first message on its own page

[PATCH v7 0/6] clk: provide new devm helpers for prepared and enabled clocks

From: Uwe Kleine-König <hidden>
Date: 2021-05-10 17:42:08

Hello,

compared to v6 I rebased to v5.13-rc1 (which resulted in a conflict in
the pwm-atmel patch), reformated the doc comments in patch 2 (as
suggested by Jonathan Cameron) and added the two Reviewed-by tags for
Jonathan Cameron.

Best regards
Uwe

Uwe Kleine-König (6):
  clk: generalize devm_clk_get() a bit
  clk: Provide new devm_clk_helpers for prepared and enabled clocks
  pwm: atmel: Simplify using devm_clk_get_prepared()
  rtc: at91sam9: Simplify using devm_clk_get_enabled()
  i2c: imx: Simplify using devm_clk_get_enabled()
  spi: davinci: Simplify using devm_clk_get_enabled()

 drivers/clk/clk-devres.c     | 96 ++++++++++++++++++++++++++++++------
 drivers/i2c/busses/i2c-imx.c | 12 +----
 drivers/pwm/pwm-atmel.c      | 15 +-----
 drivers/rtc/rtc-at91sam9.c   | 22 ++-------
 drivers/spi/spi-davinci.c    | 11 +----
 include/linux/clk.h          | 90 ++++++++++++++++++++++++++++++++-
 6 files changed, 179 insertions(+), 67 deletions(-)


base-commit: 6efb943b8616ec53a5e444193dccf1af9ad627b5
-- 
2.30.2


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[PATCH v7 5/6] i2c: imx: Simplify using devm_clk_get_enabled()

From: Uwe Kleine-König <hidden>
Date: 2021-05-10 17:41:57

devm_clk_get_enabled() returns the clk already (prepared and) enabled
and the automatically called cleanup cares for disabling (and
unpreparing). So simplify .probe() and .remove() accordingly.

Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Uwe Kleine-König <redacted>
---
 drivers/i2c/busses/i2c-imx.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index dc5ca71906db..13241401ad88 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -1405,16 +1405,10 @@ static int i2c_imx_probe(struct platform_device *pdev)
 	ACPI_COMPANION_SET(&i2c_imx->adapter.dev, ACPI_COMPANION(&pdev->dev));
 
 	/* Get I2C clock */
-	i2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
+	i2c_imx->clk = devm_clk_get_enabled(&pdev->dev, NULL);
 	if (IS_ERR(i2c_imx->clk))
 		return dev_err_probe(&pdev->dev, PTR_ERR(i2c_imx->clk),
-				     "can't get I2C clock\n");
-
-	ret = clk_prepare_enable(i2c_imx->clk);
-	if (ret) {
-		dev_err(&pdev->dev, "can't enable I2C clock, ret=%d\n", ret);
-		return ret;
-	}
+				     "can't get prepared I2C clock\n");
 
 	/* Init queue */
 	init_waitqueue_head(&i2c_imx->queue);
@@ -1487,7 +1481,6 @@ static int i2c_imx_probe(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);
 	pm_runtime_dont_use_autosuspend(&pdev->dev);
-	clk_disable_unprepare(i2c_imx->clk);
 	return ret;
 }
 
@@ -1517,7 +1510,6 @@ static int i2c_imx_remove(struct platform_device *pdev)
 	irq = platform_get_irq(pdev, 0);
 	if (irq >= 0)
 		free_irq(irq, i2c_imx);
-	clk_disable_unprepare(i2c_imx->clk);
 
 	pm_runtime_put_noidle(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
-- 
2.30.2


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[PATCH v7 4/6] rtc: at91sam9: Simplify using devm_clk_get_enabled()

From: Uwe Kleine-König <hidden>
Date: 2021-05-10 17:41:58

devm_clk_get_enabled() returns the clk already (prepared and) enabled
and the automatically called cleanup cares for disabling (and
unpreparing). So simplify .probe() and .remove() accordingly.

Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Uwe Kleine-König <redacted>
---
 drivers/rtc/rtc-at91sam9.c | 22 ++++------------------
 1 file changed, 4 insertions(+), 18 deletions(-)
diff --git a/drivers/rtc/rtc-at91sam9.c b/drivers/rtc/rtc-at91sam9.c
index 2216be429ab7..b52e7bd26303 100644
--- a/drivers/rtc/rtc-at91sam9.c
+++ b/drivers/rtc/rtc-at91sam9.c
@@ -374,21 +374,14 @@ static int at91_rtc_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
-	rtc->sclk = devm_clk_get(&pdev->dev, NULL);
+	rtc->sclk = devm_clk_get_enabled(&pdev->dev, NULL);
 	if (IS_ERR(rtc->sclk))
 		return PTR_ERR(rtc->sclk);
 
-	ret = clk_prepare_enable(rtc->sclk);
-	if (ret) {
-		dev_err(&pdev->dev, "Could not enable slow clock\n");
-		return ret;
-	}
-
 	sclk_rate = clk_get_rate(rtc->sclk);
 	if (!sclk_rate || sclk_rate > AT91_RTT_RTPRES) {
 		dev_err(&pdev->dev, "Invalid slow clock rate\n");
-		ret = -EINVAL;
-		goto err_clk;
+		return -EINVAL;
 	}
 
 	mr = rtt_readl(rtc, MR);
@@ -406,7 +399,7 @@ static int at91_rtc_probe(struct platform_device *pdev)
 	rtc->rtcdev = devm_rtc_allocate_device(&pdev->dev);
 	if (IS_ERR(rtc->rtcdev)) {
 		ret = PTR_ERR(rtc->rtcdev);
-		goto err_clk;
+		return ret;
 	}
 
 	rtc->rtcdev->ops = &at91_rtc_ops;
@@ -418,7 +411,7 @@ static int at91_rtc_probe(struct platform_device *pdev)
 			       dev_name(&rtc->rtcdev->dev), rtc);
 	if (ret) {
 		dev_dbg(&pdev->dev, "can't share IRQ %d?\n", rtc->irq);
-		goto err_clk;
+		return ret;
 	}
 
 	/* NOTE:  sam9260 rev A silicon has a ROM bug which resets the
@@ -432,11 +425,6 @@ static int at91_rtc_probe(struct platform_device *pdev)
 			 dev_name(&rtc->rtcdev->dev));
 
 	return devm_rtc_register_device(rtc->rtcdev);
-
-err_clk:
-	clk_disable_unprepare(rtc->sclk);
-
-	return ret;
 }
 
 /*
@@ -450,8 +438,6 @@ static int at91_rtc_remove(struct platform_device *pdev)
 	/* disable all interrupts */
 	rtt_writel(rtc, MR, mr & ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN));
 
-	clk_disable_unprepare(rtc->sclk);
-
 	return 0;
 }
 
-- 
2.30.2


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[PATCH v7 1/6] clk: generalize devm_clk_get() a bit

From: Uwe Kleine-König <hidden>
Date: 2021-05-10 17:42:02

Allow to add an exit hook to devm managed clocks. Also use
clk_get_optional() in devm_clk_get_optional instead of open coding it.
The generalisation will be used in the next commit to add some more
devm_clk helpers.

Reviewed-by: Jonathan Cameron <redacted>
Signed-off-by: Uwe Kleine-König <redacted>
---
 drivers/clk/clk-devres.c | 67 ++++++++++++++++++++++++++++++----------
 1 file changed, 50 insertions(+), 17 deletions(-)
diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c
index be160764911b..91c995815b57 100644
--- a/drivers/clk/clk-devres.c
+++ b/drivers/clk/clk-devres.c
@@ -4,39 +4,72 @@
 #include <linux/export.h>
 #include <linux/gfp.h>
 
+struct devm_clk_state {
+	struct clk *clk;
+	void (*exit)(struct clk *clk);
+};
+
 static void devm_clk_release(struct device *dev, void *res)
 {
-	clk_put(*(struct clk **)res);
+	struct devm_clk_state *state = *(struct devm_clk_state **)res;
+
+	if (state->exit)
+		state->exit(state->clk);
+
+	clk_put(state->clk);
 }
 
-struct clk *devm_clk_get(struct device *dev, const char *id)
+static struct clk *__devm_clk_get(struct device *dev, const char *id,
+				  struct clk *(*get)(struct device *dev, const char *id),
+				  int (*init)(struct clk *clk),
+				  void (*exit)(struct clk *clk))
 {
-	struct clk **ptr, *clk;
+	struct devm_clk_state *state;
+	struct clk *clk;
+	int ret;
 
-	ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL);
-	if (!ptr)
+	state = devres_alloc(devm_clk_release, sizeof(*state), GFP_KERNEL);
+	if (!state)
 		return ERR_PTR(-ENOMEM);
 
-	clk = clk_get(dev, id);
-	if (!IS_ERR(clk)) {
-		*ptr = clk;
-		devres_add(dev, ptr);
-	} else {
-		devres_free(ptr);
+	clk = get(dev, id);
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		goto err_clk_get;
 	}
 
+	if (init) {
+		ret = init(clk);
+		if (ret)
+			goto err_clk_init;
+	}
+
+	state->clk = clk;
+	state->exit = exit;
+
+	devres_add(dev, state);
+
 	return clk;
+
+err_clk_init:
+
+	clk_put(clk);
+err_clk_get:
+
+	devres_free(state);
+	return ERR_PTR(ret);
 }
-EXPORT_SYMBOL(devm_clk_get);
 
-struct clk *devm_clk_get_optional(struct device *dev, const char *id)
+struct clk *devm_clk_get(struct device *dev, const char *id)
 {
-	struct clk *clk = devm_clk_get(dev, id);
+	return __devm_clk_get(dev, id, clk_get, NULL, NULL);
 
-	if (clk == ERR_PTR(-ENOENT))
-		return NULL;
+}
+EXPORT_SYMBOL(devm_clk_get);
 
-	return clk;
+struct clk *devm_clk_get_optional(struct device *dev, const char *id)
+{
+	return __devm_clk_get(dev, id, clk_get_optional, NULL, NULL);
 }
 EXPORT_SYMBOL(devm_clk_get_optional);
 
-- 
2.30.2


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[PATCH v7 2/6] clk: Provide new devm_clk_helpers for prepared and enabled clocks

From: Uwe Kleine-König <hidden>
Date: 2021-05-10 17:42:05

When a driver keeps a clock prepared (or enabled) during the whole
lifetime of the driver, these helpers allow to simplify the drivers.

Reviewed-by: Jonathan Cameron <redacted>
Signed-off-by: Uwe Kleine-König <redacted>
---
 drivers/clk/clk-devres.c | 31 ++++++++++++++
 include/linux/clk.h      | 90 +++++++++++++++++++++++++++++++++++++++-
 2 files changed, 120 insertions(+), 1 deletion(-)
diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c
index 91c995815b57..b54f7f0f2a35 100644
--- a/drivers/clk/clk-devres.c
+++ b/drivers/clk/clk-devres.c
@@ -67,12 +67,43 @@ struct clk *devm_clk_get(struct device *dev, const char *id)
 }
 EXPORT_SYMBOL(devm_clk_get);
 
+struct clk *devm_clk_get_prepared(struct device *dev, const char *id)
+{
+	return __devm_clk_get(dev, id, clk_get, clk_prepare, clk_unprepare);
+
+}
+EXPORT_SYMBOL(devm_clk_get_prepared);
+
+struct clk *devm_clk_get_enabled(struct device *dev, const char *id)
+{
+	return __devm_clk_get(dev, id, clk_get,
+			      clk_prepare_enable, clk_disable_unprepare);
+
+}
+EXPORT_SYMBOL(devm_clk_get_enabled);
+
 struct clk *devm_clk_get_optional(struct device *dev, const char *id)
 {
 	return __devm_clk_get(dev, id, clk_get_optional, NULL, NULL);
 }
 EXPORT_SYMBOL(devm_clk_get_optional);
 
+struct clk *devm_clk_get_optional_prepared(struct device *dev, const char *id)
+{
+	return __devm_clk_get(dev, id, clk_get_optional,
+			      clk_prepare, clk_unprepare);
+
+}
+EXPORT_SYMBOL(devm_clk_get_optional_prepared);
+
+struct clk *devm_clk_get_optional_enabled(struct device *dev, const char *id)
+{
+	return __devm_clk_get(dev, id, clk_get_optional,
+			      clk_prepare_enable, clk_disable_unprepare);
+
+}
+EXPORT_SYMBOL(devm_clk_get_optional_enabled);
+
 struct clk_bulk_devres {
 	struct clk_bulk_data *clks;
 	int num_clks;
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 266e8de3cb51..b011dbba7109 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -449,7 +449,7 @@ int __must_check devm_clk_bulk_get_all(struct device *dev,
  * the clock producer.  (IOW, @id may be identical strings, but
  * clk_get may return different clock producers depending on @dev.)
  *
- * Drivers must assume that the clock source is not enabled.
+ * Drivers must assume that the clock source is neither prepared nor enabled.
  *
  * devm_clk_get should not be called from within interrupt context.
  *
@@ -458,6 +458,47 @@ int __must_check devm_clk_bulk_get_all(struct device *dev,
  */
 struct clk *devm_clk_get(struct device *dev, const char *id);
 
+/**
+ * devm_clk_get_prepared - devm_clk_get() + clk_prepare()
+ * @dev: device for clock "consumer"
+ * @id: clock consumer ID
+ *
+ * Returns a struct clk corresponding to the clock producer, or
+ * valid IS_ERR() condition containing errno.  The implementation
+ * uses @dev and @id to determine the clock consumer, and thereby
+ * the clock producer.  (IOW, @id may be identical strings, but
+ * clk_get may return different clock producers depending on @dev.)
+ *
+ * The returned clk (if valid) is prepared. Drivers must however assume that the
+ * clock is not enabled.
+ *
+ * devm_clk_get_prepared should not be called from within interrupt context.
+ *
+ * The clock will automatically be unprepared and freed when the
+ * device is unbound from the bus.
+ */
+struct clk *devm_clk_get_prepared(struct device *dev, const char *id);
+
+/**
+ * devm_clk_get_enabled - devm_clk_get() + clk_prepare_enable()
+ * @dev: device for clock "consumer"
+ * @id: clock consumer ID
+ *
+ * Returns a struct clk corresponding to the clock producer, or valid IS_ERR()
+ * condition containing errno.  The implementation uses @dev and @id to
+ * determine the clock consumer, and thereby the clock producer.  (IOW, @id may
+ * be identical strings, but clk_get may return different clock producers
+ * depending on @dev.)
+ *
+ * The returned clk (if valid) is prepared and enabled.
+ *
+ * devm_clk_get_prepared should not be called from within interrupt context.
+ *
+ * The clock will automatically be disabled, unprepared and freed when the
+ * device is unbound from the bus.
+ */
+struct clk *devm_clk_get_enabled(struct device *dev, const char *id);
+
 /**
  * devm_clk_get_optional - lookup and obtain a managed reference to an optional
  *			   clock producer.
@@ -469,6 +510,29 @@ struct clk *devm_clk_get(struct device *dev, const char *id);
  */
 struct clk *devm_clk_get_optional(struct device *dev, const char *id);
 
+/**
+ * devm_clk_get_optional_prepared - devm_clk_get_optional() + clk_prepare()
+ * @dev: device for clock "consumer"
+ * @id: clock consumer ID
+ *
+ * Behaves the same as devm_clk_get_prepared() except where there is no clock
+ * producer.  In this case, instead of returning -ENOENT, the function returns
+ * NULL.
+ */
+struct clk *devm_clk_get_optional_prepared(struct device *dev, const char *id);
+
+/**
+ * devm_clk_get_optional_enabled - devm_clk_get_optional() +
+ *                                 clk_prepare_enable()
+ * @dev: device for clock "consumer"
+ * @id: clock consumer ID
+ *
+ * Behaves the same as devm_clk_get_enabled() except where there is no clock
+ * producer.  In this case, instead of returning -ENOENT, the function returns
+ * NULL.
+ */
+struct clk *devm_clk_get_optional_enabled(struct device *dev, const char *id);
+
 /**
  * devm_get_clk_from_child - lookup and obtain a managed reference to a
  *			     clock producer from child node.
@@ -813,12 +877,36 @@ static inline struct clk *devm_clk_get(struct device *dev, const char *id)
 	return NULL;
 }
 
+static inline struct clk *devm_clk_get_prepared(struct device *dev,
+						const char *id)
+{
+	return NULL;
+}
+
+static inline struct clk *devm_clk_get_enabled(struct device *dev,
+					       const char *id)
+{
+	return NULL;
+}
+
 static inline struct clk *devm_clk_get_optional(struct device *dev,
 						const char *id)
 {
 	return NULL;
 }
 
+static inline struct clk *devm_clk_get_optional_prepared(struct device *dev,
+							 const char *id)
+{
+	return NULL;
+}
+
+static inline struct clk *devm_clk_get_optional_enabled(struct device *dev,
+							const char *id)
+{
+	return NULL;
+}
+
 static inline int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
 						 struct clk_bulk_data *clks)
 {
-- 
2.30.2


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Re: [PATCH v7 0/6] clk: provide new devm helpers for prepared and enabled clocks

From: Alexandru Ardelean <hidden>
Date: 2021-05-11 07:58:22

On Mon, 10 May 2021 at 20:41, Uwe Kleine-König
[off-list ref] wrote:
Hello,

compared to v6 I rebased to v5.13-rc1 (which resulted in a conflict in
the pwm-atmel patch), reformated the doc comments in patch 2 (as
suggested by Jonathan Cameron) and added the two Reviewed-by tags for
Jonathan Cameron.
This will definitely cleanup a lot of boiler-plate code for probe()/remove().
What I'm noticing, is that some remove hooks [in the drivers in this
series] are being slightly re-ordered;
i.e. the clk_disable/unprepare may happen in a slightly different
order, but it doesn't look like those would be problematic.

So, for the series:
Reviewed-by: Alexandru Ardelean <redacted>

Thanks
Alex
Best regards
Uwe

Uwe Kleine-König (6):
  clk: generalize devm_clk_get() a bit
  clk: Provide new devm_clk_helpers for prepared and enabled clocks
  pwm: atmel: Simplify using devm_clk_get_prepared()
  rtc: at91sam9: Simplify using devm_clk_get_enabled()
  i2c: imx: Simplify using devm_clk_get_enabled()
  spi: davinci: Simplify using devm_clk_get_enabled()

 drivers/clk/clk-devres.c     | 96 ++++++++++++++++++++++++++++++------
 drivers/i2c/busses/i2c-imx.c | 12 +----
 drivers/pwm/pwm-atmel.c      | 15 +-----
 drivers/rtc/rtc-at91sam9.c   | 22 ++-------
 drivers/spi/spi-davinci.c    | 11 +----
 include/linux/clk.h          | 90 ++++++++++++++++++++++++++++++++-
 6 files changed, 179 insertions(+), 67 deletions(-)


base-commit: 6efb943b8616ec53a5e444193dccf1af9ad627b5
--
2.30.2
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Re: [PATCH v7 0/6] clk: provide new devm helpers for prepared and enabled clocks

From: Uwe Kleine-König <hidden>
Date: 2021-05-24 11:10:22

On Mon, May 10, 2021 at 07:41:36PM +0200, Uwe Kleine-König wrote:
compared to v6 I rebased to v5.13-rc1 (which resulted in a conflict in
the pwm-atmel patch), reformated the doc comments in patch 2 (as
suggested by Jonathan Cameron) and added the two Reviewed-by tags for
Jonathan Cameron.
Another two weeks without maintainer feedback. I didn't find a single
mail by either Michael Turquette nor by Stephen Boyd on the linux-clk
list on lore dating from this month. This patch set didn't get a reply
since more than half a year.

Is the clk tree still maintained?  Would a pull request help? There are
several people who expressed interest in this series and the cleanup it
allows.

@Andrew: Would you be willing to take the first two patches if Michael
and Stephen don't react in the near future?

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |
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