[PATCH v1 0/7] Timer driver module support

[PATCH v1 0/7] Timer driver module support

[Daniel Lezcano]

Converting the timer driver modules requires a particular care
because, depending on the platform, that may be not supported.

A previous study showed we are safe regarding how the module refcount
is held and if THIS_MODULE is set for the clockevent and the
clocksource when they are registered.

It won't be possible to unload a module if a clockevent is registered.

It will be possible to unload a module if only a clocksource is
registered and it is not the current one.

However platforms without architected timers may need the timer driver
to be initialized very early and others can be initialized later. The
former can not be a module and the init function receives a
device_node pointer, there is no device associated and devres is not
used. That results in a lot of rollbacking code where usually it is
where we find bug and resource leaks. The latter can be converted to a
module and uses a module_platform_driver(), thus the init function is
a probe function receiving a struct platform_device pointer parameter.

We end up with two approaches and duplicate code for the init
functions. This is not optimal.

Finally, we have the driver having to be initialized very early on
some platforms and be built as a module on other platforms, resulting
on having two init functions co-existing in the same driver.

This series provides what is needed to move to the same probe function
for early init, builtin and module timers.

A new macro is introduced: TIMER_PDEV_DECLARE() and a new Kconfig
option is added CONFIG_EARLY_TIMER. TIMER_PDEV_DECLARE() will have
different behavior depending on the context:

 - The driver is a module and CONFIG_EARLY_TIMER=no
   --> the driver is a module

 - The driver is builtin and CONFIG_EARLY_TIMER=no
   --> the driver is loaded later

 - The driver is builtin or a module but CONFIG_EARLY_TIMER=yes
   --> the driver is initialized through the timer-probe function

The different timer driver framework functions have their __init
sections removed and the symbols exported in order to be compatible
with the drivers converted into modules.

The series provides a couple of drivers changed. The Mediatek as a
recent requested target which is only compiled-tested. The Rockchip
timer which was tested on a rk3588 in the three different
configurations.

Daniel Lezcano (7):
  clocksource/drivers/timer-probe: Create a platform_device before the
    framework is initialized
  drivers/clocksource/rockchip: Use the TIMER_PDEV_DECLARE() macro
  clocksource/drivers/mmio: Make the code compatible with modules
  clocksource/drivers/timer-of: Make the code compatible with modules
  clocksource/drivers/timer-probe: Add the module support for the
    TIMER_PDEV_DECLARE() macro
  clocksource/drivers/rockchip: Add rockchip timer module support
  clocksource/drivers/mediatek: Convert to module support

 drivers/clocksource/Kconfig          |   7 +-
 drivers/clocksource/mmio.c           |  11 ++-
 drivers/clocksource/timer-mediatek.c |  29 ++++++--
 drivers/clocksource/timer-of.c       |  24 ++++---
 drivers/clocksource/timer-of.h       |   5 +-
 drivers/clocksource/timer-probe.c    |  69 ++++++++++++++++--
 drivers/clocksource/timer-rockchip.c | 101 ++++++++++-----------------
 include/asm-generic/vmlinux.lds.h    |  10 +++
 include/linux/clocksource.h          |  31 ++++++++
 9 files changed, 194 insertions(+), 93 deletions(-)

-- 
2.43.0

[PATCH v1 1/7] clocksource/drivers/timer-probe: Create a platform_device before the framework is initialized

[Daniel Lezcano]

From: Daniel Lezcano <daniel.lezcano@linaro.org>

In the context of the time keeping and the timers, some platforms have
timers which need to be initialized very early. It is the case of the
ARM platform which do not have the architected timers.

The macro TIMER_OF_DECLARE adds an entry in the timer init functions
array at compile time and the function timer_probe is called from the
timer_init() function in kernel/time.c

This array contains a tuple with the init function and the compatible
string.

The init function has a device node pointer parameter.

The timer_probe() function browses the of nodes and find the ones
matching the compatible string given when using the TIMER_OF_DECLARE
macro. It then calls the init function with the device node as a
pointer.

But there are some platforms where there are multiple timers like the
ARM64 with the architected timers. Those are always initialized very
early and the other timers can be initialized later.

For this reason we find timer drivers with the platform_driver
incarnation. Consequently their init functions are different, they
have a platform_device pointer parameter and rely on the devm_
function for rollbacking.

To summarize, we have:
 - TIMER_OF_DECLARE with init function prototype:
   int (*init)(struct device_node *np);

 - module_platform_driver (and variant) with the probe function
   prototype:
   int (*init)(struct platform_device *pdev);

The current situation with the timers is the following:

 - Two platforms can have the same timer hardware, hence the same
   driver but one without alternate timers and the other with multiple
   timers. For example, the Exynos platform has only the Exynos MCT on
   ARM but has the architeched timers in addition on the ARM64.

 - The timer drivers can be modules now which was not the case until
   recently. TIMER_OF_DECLARE do not allow the build as a module.

It results in duplicate init functions (one with rollback and one with
devm_) and different way to declare the driver (TIMER_OF_DECLARE and
module_platform_driver).

This proposed change is to unify the prototyping of the init functions
to receive a platform_device pointer as parameter. Consequently, it
will allow a smoother and nicer module conversion and a huge cleanup
of the init functions by removing all the rollback code from all the
timer drivers. It introduces a TIMER_PDEV_DECLARE() macro.

If the macro is used a platform_device is manually allocated and
initialized with the needed information for the probe
function. Otherwise module_platform_driver can be use instead with the
same probe function without the timer_probe() initialization.

The plan is to have all timers to use TIMER_PDEV_DECLARE with all the
init functions optimized and then remove the TIMER_OF_DECLARE macro.

Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
Cc: Hans de Goede <hansg@kernel.org>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/clocksource/timer-probe.c | 66 +++++++++++++++++++++++++++++--
 include/asm-generic/vmlinux.lds.h | 10 +++++
 include/linux/clocksource.h       | 21 ++++++++++
 3 files changed, 93 insertions(+), 4 deletions(-)

diff --git a/drivers/clocksource/timer-probe.c b/drivers/clocksource/timer-probe.c
index b7860bc0db4b..cdaceb68d356 100644
--- a/drivers/clocksource/timer-probe.c
+++ b/drivers/clocksource/timer-probe.c
@@ -7,13 +7,11 @@
 #include <linux/init.h>
 #include <linux/of.h>
 #include <linux/clocksource.h>
+#include <linux/platform_device.h>
 
 extern struct of_device_id __timer_of_table[];
 
-static const struct of_device_id __timer_of_table_sentinel
-	__used __section("__timer_of_table_end");
-
-void __init timer_probe(void)
+static int __init timer_of_probe(void)
 {
 	struct device_node *np;
 	const struct of_device_id *match;
@@ -38,6 +36,66 @@ void __init timer_probe(void)
 		timers++;
 	}
 
+	return timers;
+}
+
+static int __init __timer_pdev_probe(struct platform_driver *drv)
+{
+	struct device_node *np;
+	struct platform_device *pdev;
+	const struct of_device_id *match;
+	unsigned int timers = 0;
+	int ret;
+
+	for_each_matching_node_and_match(np, drv->driver.of_match_table, &match) {
+		if (!of_device_is_available(np))
+			continue;
+
+		pdev = platform_device_alloc(of_node_full_name(np), -1);
+		if (!pdev)
+			continue;
+
+		ret = device_add_of_node(&pdev->dev, np);
+		if (ret) {
+			platform_device_put(pdev);
+			continue;
+		}
+
+		dev_set_name(&pdev->dev, pdev->name);
+
+		ret = drv->probe(pdev);
+		if (!ret) {
+			timers++;
+			continue;
+		}
+
+		if (ret != -EPROBE_DEFER)
+			pr_err("Failed to initialize '%pOF': %d\n", np, ret);
+
+		device_remove_of_node(&pdev->dev);
+
+		platform_device_put(pdev);
+	}
+
+	return timers;
+}
+
+static int __init timer_pdev_probe(void)
+{
+	struct platform_driver **drv;
+
+	for_each_pdev_timer_table(drv)
+		__timer_pdev_probe(*drv);
+
+	return 0;
+}
+
+void __init timer_probe(void)
+{
+	unsigned timers = 0;
+
+	timers += timer_of_probe();
+	timers += timer_pdev_probe();
 	timers += acpi_probe_device_table(timer);
 
 	if (!timers)
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index eeb070f330bd..5d619e831dce 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -359,6 +359,15 @@
 #define THERMAL_TABLE(name)
 #endif
 
+#ifdef CONFIG_TIMER_OF
+#define TIMER_TABLE(name)						\
+	. = ALIGN(8);							\
+	BOUNDED_SECTION_POST_LABEL(__##name##_timer_table,		\
+				   __##name##_timer_table,, _end)
+#else
+#define TIMER_TABLE(name)
+#endif
+
 #define KERNEL_DTB()							\
 	STRUCT_ALIGN();							\
 	__dtb_start = .;						\
@@ -738,6 +747,7 @@
 	ACPI_PROBE_TABLE(irqchip)					\
 	ACPI_PROBE_TABLE(timer)						\
 	THERMAL_TABLE(governor)						\
+	TIMER_TABLE(pdev)						\
 	EARLYCON_TABLE()						\
 	LSM_TABLE()							\
 	EARLY_LSM_TABLE()						\
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 65b7c41471c3..6e05b78e64b8 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -18,6 +18,7 @@
 #include <linux/init.h>
 #include <linux/of.h>
 #include <linux/clocksource_ids.h>
+#include <linux/platform_device.h>
 #include <asm/div64.h>
 #include <asm/io.h>
 
@@ -295,6 +296,26 @@ extern void timer_probe(void);
 static inline void timer_probe(void) {}
 #endif
 
+extern struct platform_driver *__pdev_timer_table[];
+extern struct platform_driver *__pdev_timer_table_end[];
+
+#define TIMER_PDEV_DECLARE(__name, __probe, __remove, __match)		\
+	static struct platform_driver __pdev_timer_table_entry_##__name = { \
+		.probe = __probe,					\
+		.remove = __remove,					\
+		.driver = {						\
+			.name = #__name,				\
+			.of_match_table = __match			\
+		},							\
+	};								\
+	static struct platform_driver *___pdev_timer_table_entry_##__name \
+	__used __section("__pdev_timer_table") = &__pdev_timer_table_entry_##__name
+
+#define for_each_pdev_timer_table(__pdev)     \
+	for (__pdev = __pdev_timer_table;     \
+	     __pdev < __pdev_timer_table_end; \
+	     __pdev++)
+
 #define TIMER_ACPI_DECLARE(name, table_id, fn)		\
 	ACPI_DECLARE_PROBE_ENTRY(timer, name, table_id, 0, NULL, 0, fn)
 
-- 
2.43.0

[PATCH v1 2/7] clocksource/drivers/mmio: Make the code compatible with modules

[Daniel Lezcano]

The next changes will bring the module support on the timer
drivers. Those use the API exported by the mmio clocksource which are
not exporting their symbols. Fix that by adding EXPORT_SYMBOL_GPL().

Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
---
 drivers/clocksource/mmio.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/clocksource/mmio.c b/drivers/clocksource/mmio.c
index cd5fbf49ac29..0fee8edb837a 100644
--- a/drivers/clocksource/mmio.c
+++ b/drivers/clocksource/mmio.c
@@ -21,21 +21,25 @@ u64 clocksource_mmio_readl_up(struct clocksource *c)
 {
 	return (u64)readl_relaxed(to_mmio_clksrc(c)->reg);
 }
+EXPORT_SYMBOL_GPL(clocksource_mmio_readl_up);
 
 u64 clocksource_mmio_readl_down(struct clocksource *c)
 {
 	return ~(u64)readl_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
 }
+EXPORT_SYMBOL_GPL(clocksource_mmio_readl_down);
 
 u64 clocksource_mmio_readw_up(struct clocksource *c)
 {
 	return (u64)readw_relaxed(to_mmio_clksrc(c)->reg);
 }
+EXPORT_SYMBOL_GPL(clocksource_mmio_readw_up);
 
 u64 clocksource_mmio_readw_down(struct clocksource *c)
 {
 	return ~(u64)readw_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
 }
+EXPORT_SYMBOL_GPL(clocksource_mmio_readw_down);
 
 /**
  * clocksource_mmio_init - Initialize a simple mmio based clocksource
@@ -46,9 +50,9 @@ u64 clocksource_mmio_readw_down(struct clocksource *c)
  * @bits:	Number of valid bits
  * @read:	One of clocksource_mmio_read*() above
  */
-int __init clocksource_mmio_init(void __iomem *base, const char *name,
-	unsigned long hz, int rating, unsigned bits,
-	u64 (*read)(struct clocksource *))
+int clocksource_mmio_init(void __iomem *base, const char *name,
+			  unsigned long hz, int rating, unsigned bits,
+			  u64 (*read)(struct clocksource *))
 {
 	struct clocksource_mmio *cs;
 
@@ -68,3 +72,4 @@ int __init clocksource_mmio_init(void __iomem *base, const char *name,
 
 	return clocksource_register_hz(&cs->clksrc, hz);
 }
+EXPORT_SYMBOL_GPL(clocksource_mmio_init);
-- 
2.43.0

[PATCH v1 2/7] drivers/clocksource/rockchip: Use the TIMER_PDEV_DECLARE() macro

[Daniel Lezcano]

The previous change introduce the TIMER_PDEV_DECLARE() marco which
allows to use the platform driver to initialize a timer driver with
the benefit of having the devres to rollback automatically in case of
error.

Use this macro and change the function to rely on the devm_ variants,
allowing to cleanup the code.

Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
---
 drivers/clocksource/timer-rockchip.c | 99 ++++++++++------------------
 1 file changed, 34 insertions(+), 65 deletions(-)

diff --git a/drivers/clocksource/timer-rockchip.c b/drivers/clocksource/timer-rockchip.c
index 540a16667145..486bbffba464 100644
--- a/drivers/clocksource/timer-rockchip.c
+++ b/drivers/clocksource/timer-rockchip.c
@@ -124,18 +124,18 @@ static u64 notrace rk_timer_sched_read(void)
 	return ~readl_relaxed(rk_clksrc->base + TIMER_CURRENT_VALUE0);
 }
 
-static int __init
-rk_timer_probe(struct rk_timer *timer, struct device_node *np)
+static int rk_timer_init(struct rk_timer *timer, struct device *dev)
 {
+	struct device_node *np = dev->of_node;
 	struct clk *timer_clk;
 	struct clk *pclk;
-	int ret = -EINVAL, irq;
+	int irq;
 	u32 ctrl_reg = TIMER_CONTROL_REG3288;
 
-	timer->base = of_iomap(np, 0);
-	if (!timer->base) {
+	timer->base = devm_of_iomap(dev, np, 0, NULL);
+	if (IS_ERR(timer->base)) {
 		pr_err("Failed to get base address for '%s'\n", TIMER_NAME);
-		return -ENXIO;
+		return PTR_ERR(timer->base);
 	}
 
 	if (of_device_is_compatible(np, "rockchip,rk3399-timer"))
@@ -143,31 +143,17 @@ rk_timer_probe(struct rk_timer *timer, struct device_node *np)
 
 	timer->ctrl = timer->base + ctrl_reg;
 
-	pclk = of_clk_get_by_name(np, "pclk");
+	pclk = devm_clk_get_enabled(dev, "pclk");
 	if (IS_ERR(pclk)) {
-		ret = PTR_ERR(pclk);
 		pr_err("Failed to get pclk for '%s'\n", TIMER_NAME);
-		goto out_unmap;
-	}
-
-	ret = clk_prepare_enable(pclk);
-	if (ret) {
-		pr_err("Failed to enable pclk for '%s'\n", TIMER_NAME);
-		goto out_unmap;
+		return PTR_ERR(pclk);
 	}
 	timer->pclk = pclk;
 
-	timer_clk = of_clk_get_by_name(np, "timer");
+	timer_clk = devm_clk_get_enabled(dev, "timer");
 	if (IS_ERR(timer_clk)) {
-		ret = PTR_ERR(timer_clk);
 		pr_err("Failed to get timer clock for '%s'\n", TIMER_NAME);
-		goto out_timer_clk;
-	}
-
-	ret = clk_prepare_enable(timer_clk);
-	if (ret) {
-		pr_err("Failed to enable timer clock\n");
-		goto out_timer_clk;
+		return PTR_ERR(timer_clk);
 	}
 	timer->clk = timer_clk;
 
@@ -175,47 +161,32 @@ rk_timer_probe(struct rk_timer *timer, struct device_node *np)
 
 	irq = irq_of_parse_and_map(np, 0);
 	if (!irq) {
-		ret = -EINVAL;
 		pr_err("Failed to map interrupts for '%s'\n", TIMER_NAME);
-		goto out_irq;
+		return -EINVAL;
 	}
 	timer->irq = irq;
 
 	rk_timer_interrupt_clear(timer);
 	rk_timer_disable(timer);
-	return 0;
-
-out_irq:
-	clk_disable_unprepare(timer_clk);
-out_timer_clk:
-	clk_disable_unprepare(pclk);
-out_unmap:
-	iounmap(timer->base);
-
-	return ret;
-}
 
-static void __init rk_timer_cleanup(struct rk_timer *timer)
-{
-	clk_disable_unprepare(timer->clk);
-	clk_disable_unprepare(timer->pclk);
-	iounmap(timer->base);
+	return 0;
 }
 
-static int __init rk_clkevt_init(struct device_node *np)
+static int rk_clkevt_init(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct clock_event_device *ce;
 	int ret = -EINVAL;
 
-	rk_clkevt = kzalloc_obj(struct rk_clkevt);
+	rk_clkevt = devm_kzalloc(dev, sizeof(*rk_clkevt), GFP_KERNEL);
 	if (!rk_clkevt) {
 		ret = -ENOMEM;
 		goto out;
 	}
 
-	ret = rk_timer_probe(&rk_clkevt->timer, np);
+	ret = rk_timer_init(&rk_clkevt->timer, dev);
 	if (ret)
-		goto out_probe;
+		goto out;
 
 	ce = &rk_clkevt->ce;
 	ce->name = TIMER_NAME;
@@ -233,36 +204,33 @@ static int __init rk_clkevt_init(struct device_node *np)
 	if (ret) {
 		pr_err("Failed to initialize '%s': %d\n",
 			TIMER_NAME, ret);
-		goto out_irq;
+		goto out;
 	}
 
 	clockevents_config_and_register(&rk_clkevt->ce,
 					rk_clkevt->timer.freq, 1, UINT_MAX);
 	return 0;
 
-out_irq:
-	rk_timer_cleanup(&rk_clkevt->timer);
-out_probe:
-	kfree(rk_clkevt);
 out:
 	/* Leave rk_clkevt not NULL to prevent future init */
 	rk_clkevt = ERR_PTR(ret);
 	return ret;
 }
 
-static int __init rk_clksrc_init(struct device_node *np)
+static int rk_clksrc_init(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	int ret = -EINVAL;
 
-	rk_clksrc = kzalloc_obj(struct rk_timer);
+	rk_clksrc = devm_kzalloc(dev, sizeof(*rk_clksrc), GFP_KERNEL);
 	if (!rk_clksrc) {
 		ret = -ENOMEM;
 		goto out;
 	}
 
-	ret = rk_timer_probe(rk_clksrc, np);
+	ret = rk_timer_init(rk_clksrc, dev);
 	if (ret)
-		goto out_probe;
+		goto out;
 
 	rk_timer_update_counter(UINT_MAX, rk_clksrc);
 	rk_timer_enable(rk_clksrc, 0);
@@ -272,33 +240,34 @@ static int __init rk_clksrc_init(struct device_node *np)
 		clocksource_mmio_readl_down);
 	if (ret) {
 		pr_err("Failed to register clocksource\n");
-		goto out_clocksource;
+		goto out;
 	}
 
 	sched_clock_register(rk_timer_sched_read, 32, rk_clksrc->freq);
 	return 0;
 
-out_clocksource:
-	rk_timer_cleanup(rk_clksrc);
-out_probe:
-	kfree(rk_clksrc);
 out:
 	/* Leave rk_clksrc not NULL to prevent future init */
 	rk_clksrc = ERR_PTR(ret);
 	return ret;
 }
 
-static int __init rk_timer_init(struct device_node *np)
+static int rk_timer_probe(struct platform_device *pdev)
 {
 	if (!rk_clkevt)
-		return rk_clkevt_init(np);
+		return rk_clkevt_init(pdev);
 
 	if (!rk_clksrc)
-		return rk_clksrc_init(np);
+		return rk_clksrc_init(pdev);
 
 	pr_err("Too many timer definitions for '%s'\n", TIMER_NAME);
 	return -EINVAL;
 }
 
-TIMER_OF_DECLARE(rk3288_timer, "rockchip,rk3288-timer", rk_timer_init);
-TIMER_OF_DECLARE(rk3399_timer, "rockchip,rk3399-timer", rk_timer_init);
+static const struct of_device_id rk_timer_match_table[] = {
+	{ .compatible = "rockchip,rk3288-timer" },
+	{ .compatible = "rockchip,rk3399-timer" },
+	{ /* sentinel */ }
+};
+
+TIMER_PDEV_DECLARE(rk_timer, rk_timer_probe, NULL, rk_timer_match_table);
-- 
2.43.0

[PATCH v1 3/7] clocksource/drivers/mmio: Make the code compatible with modules

[Daniel Lezcano]

The next changes will bring the module support on the timer
drivers. Those use the API exported by the mmio clocksource which are
not exporting their symbols. Fix that by adding EXPORT_SYMBOL_GPL().

Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
---
 drivers/clocksource/mmio.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/clocksource/mmio.c b/drivers/clocksource/mmio.c
index cd5fbf49ac29..0fee8edb837a 100644
--- a/drivers/clocksource/mmio.c
+++ b/drivers/clocksource/mmio.c
@@ -21,21 +21,25 @@ u64 clocksource_mmio_readl_up(struct clocksource *c)
 {
 	return (u64)readl_relaxed(to_mmio_clksrc(c)->reg);
 }
+EXPORT_SYMBOL_GPL(clocksource_mmio_readl_up);
 
 u64 clocksource_mmio_readl_down(struct clocksource *c)
 {
 	return ~(u64)readl_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
 }
+EXPORT_SYMBOL_GPL(clocksource_mmio_readl_down);
 
 u64 clocksource_mmio_readw_up(struct clocksource *c)
 {
 	return (u64)readw_relaxed(to_mmio_clksrc(c)->reg);
 }
+EXPORT_SYMBOL_GPL(clocksource_mmio_readw_up);
 
 u64 clocksource_mmio_readw_down(struct clocksource *c)
 {
 	return ~(u64)readw_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
 }
+EXPORT_SYMBOL_GPL(clocksource_mmio_readw_down);
 
 /**
  * clocksource_mmio_init - Initialize a simple mmio based clocksource
@@ -46,9 +50,9 @@ u64 clocksource_mmio_readw_down(struct clocksource *c)
  * @bits:	Number of valid bits
  * @read:	One of clocksource_mmio_read*() above
  */
-int __init clocksource_mmio_init(void __iomem *base, const char *name,
-	unsigned long hz, int rating, unsigned bits,
-	u64 (*read)(struct clocksource *))
+int clocksource_mmio_init(void __iomem *base, const char *name,
+			  unsigned long hz, int rating, unsigned bits,
+			  u64 (*read)(struct clocksource *))
 {
 	struct clocksource_mmio *cs;
 
@@ -68,3 +72,4 @@ int __init clocksource_mmio_init(void __iomem *base, const char *name,
 
 	return clocksource_register_hz(&cs->clksrc, hz);
 }
+EXPORT_SYMBOL_GPL(clocksource_mmio_init);
-- 
2.43.0

[PATCH v1 3/7] clocksource/drivers/timer-of: Make the code compatible with modules

[Daniel Lezcano]

Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
---
 drivers/clocksource/timer-of.c | 24 +++++++++++++-----------
 drivers/clocksource/timer-of.h |  5 ++---
 2 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/clocksource/timer-of.c b/drivers/clocksource/timer-of.c
index 420202bf76e4..ba63433211b0 100644
--- a/drivers/clocksource/timer-of.c
+++ b/drivers/clocksource/timer-of.c
@@ -19,7 +19,7 @@
  *
  * Free the irq resource
  */
-static __init void timer_of_irq_exit(struct of_timer_irq *of_irq)
+static void timer_of_irq_exit(struct of_timer_irq *of_irq)
 {
 	struct timer_of *to = container_of(of_irq, struct timer_of, of_irq);
 
@@ -41,8 +41,8 @@ static __init void timer_of_irq_exit(struct of_timer_irq *of_irq)
  *
  * Returns 0 on success, < 0 otherwise
  */
-static __init int timer_of_irq_init(struct device_node *np,
-				    struct of_timer_irq *of_irq)
+static int timer_of_irq_init(struct device_node *np,
+			     struct of_timer_irq *of_irq)
 {
 	int ret;
 	struct timer_of *to = container_of(of_irq, struct timer_of, of_irq);
@@ -82,7 +82,7 @@ static __init int timer_of_irq_init(struct device_node *np,
  *
  * Disables and releases the refcount on the clk
  */
-static __init void timer_of_clk_exit(struct of_timer_clk *of_clk)
+static void timer_of_clk_exit(struct of_timer_clk *of_clk)
 {
 	of_clk->rate = 0;
 	clk_disable_unprepare(of_clk->clk);
@@ -98,8 +98,8 @@ static __init void timer_of_clk_exit(struct of_timer_clk *of_clk)
  *
  * Returns 0 on success, < 0 otherwise
  */
-static __init int timer_of_clk_init(struct device_node *np,
-				    struct of_timer_clk *of_clk)
+static int timer_of_clk_init(struct device_node *np,
+			     struct of_timer_clk *of_clk)
 {
 	int ret;
 
@@ -137,13 +137,13 @@ static __init int timer_of_clk_init(struct device_node *np,
 	goto out;
 }
 
-static __init void timer_of_base_exit(struct of_timer_base *of_base)
+static void timer_of_base_exit(struct of_timer_base *of_base)
 {
 	iounmap(of_base->base);
 }
 
-static __init int timer_of_base_init(struct device_node *np,
-				     struct of_timer_base *of_base)
+static  int timer_of_base_init(struct device_node *np,
+			       struct of_timer_base *of_base)
 {
 	of_base->base = of_base->name ?
 		of_io_request_and_map(np, of_base->index, of_base->name) :
@@ -156,7 +156,7 @@ static __init int timer_of_base_init(struct device_node *np,
 	return 0;
 }
 
-int __init timer_of_init(struct device_node *np, struct timer_of *to)
+int timer_of_init(struct device_node *np, struct timer_of *to)
 {
 	int ret = -EINVAL;
 	int flags = 0;
@@ -200,6 +200,7 @@ int __init timer_of_init(struct device_node *np, struct timer_of *to)
 		timer_of_base_exit(&to->of_base);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(timer_of_init);
 
 /**
  * timer_of_cleanup - release timer_of resources
@@ -208,7 +209,7 @@ int __init timer_of_init(struct device_node *np, struct timer_of *to)
  * Release the resources that has been used in timer_of_init().
  * This function should be called in init error cases
  */
-void __init timer_of_cleanup(struct timer_of *to)
+void timer_of_cleanup(struct timer_of *to)
 {
 	if (to->flags & TIMER_OF_IRQ)
 		timer_of_irq_exit(&to->of_irq);
@@ -219,3 +220,4 @@ void __init timer_of_cleanup(struct timer_of *to)
 	if (to->flags & TIMER_OF_BASE)
 		timer_of_base_exit(&to->of_base);
 }
+EXPORT_SYMBOL_GPL(timer_of_cleanup);
diff --git a/drivers/clocksource/timer-of.h b/drivers/clocksource/timer-of.h
index 01a2c6b7db06..74a632b85b47 100644
--- a/drivers/clocksource/timer-of.h
+++ b/drivers/clocksource/timer-of.h
@@ -65,9 +65,8 @@ static inline unsigned long timer_of_period(struct timer_of *to)
 	return to->of_clk.period;
 }
 
-extern int __init timer_of_init(struct device_node *np,
-				struct timer_of *to);
+int timer_of_init(struct device_node *np, struct timer_of *to);
 
-extern void __init timer_of_cleanup(struct timer_of *to);
+void timer_of_cleanup(struct timer_of *to);
 
 #endif
-- 
2.43.0

[PATCH v1 4/7] clocksource/drivers/timer-of: Make the code compatible with modules

[Daniel Lezcano]

Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
---
 drivers/clocksource/timer-of.c | 24 +++++++++++++-----------
 drivers/clocksource/timer-of.h |  5 ++---
 2 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/clocksource/timer-of.c b/drivers/clocksource/timer-of.c
index 420202bf76e4..ba63433211b0 100644
--- a/drivers/clocksource/timer-of.c
+++ b/drivers/clocksource/timer-of.c
@@ -19,7 +19,7 @@
  *
  * Free the irq resource
  */
-static __init void timer_of_irq_exit(struct of_timer_irq *of_irq)
+static void timer_of_irq_exit(struct of_timer_irq *of_irq)
 {
 	struct timer_of *to = container_of(of_irq, struct timer_of, of_irq);
 
@@ -41,8 +41,8 @@ static __init void timer_of_irq_exit(struct of_timer_irq *of_irq)
  *
  * Returns 0 on success, < 0 otherwise
  */
-static __init int timer_of_irq_init(struct device_node *np,
-				    struct of_timer_irq *of_irq)
+static int timer_of_irq_init(struct device_node *np,
+			     struct of_timer_irq *of_irq)
 {
 	int ret;
 	struct timer_of *to = container_of(of_irq, struct timer_of, of_irq);
@@ -82,7 +82,7 @@ static __init int timer_of_irq_init(struct device_node *np,
  *
  * Disables and releases the refcount on the clk
  */
-static __init void timer_of_clk_exit(struct of_timer_clk *of_clk)
+static void timer_of_clk_exit(struct of_timer_clk *of_clk)
 {
 	of_clk->rate = 0;
 	clk_disable_unprepare(of_clk->clk);
@@ -98,8 +98,8 @@ static __init void timer_of_clk_exit(struct of_timer_clk *of_clk)
  *
  * Returns 0 on success, < 0 otherwise
  */
-static __init int timer_of_clk_init(struct device_node *np,
-				    struct of_timer_clk *of_clk)
+static int timer_of_clk_init(struct device_node *np,
+			     struct of_timer_clk *of_clk)
 {
 	int ret;
 
@@ -137,13 +137,13 @@ static __init int timer_of_clk_init(struct device_node *np,
 	goto out;
 }
 
-static __init void timer_of_base_exit(struct of_timer_base *of_base)
+static void timer_of_base_exit(struct of_timer_base *of_base)
 {
 	iounmap(of_base->base);
 }
 
-static __init int timer_of_base_init(struct device_node *np,
-				     struct of_timer_base *of_base)
+static  int timer_of_base_init(struct device_node *np,
+			       struct of_timer_base *of_base)
 {
 	of_base->base = of_base->name ?
 		of_io_request_and_map(np, of_base->index, of_base->name) :
@@ -156,7 +156,7 @@ static __init int timer_of_base_init(struct device_node *np,
 	return 0;
 }
 
-int __init timer_of_init(struct device_node *np, struct timer_of *to)
+int timer_of_init(struct device_node *np, struct timer_of *to)
 {
 	int ret = -EINVAL;
 	int flags = 0;
@@ -200,6 +200,7 @@ int __init timer_of_init(struct device_node *np, struct timer_of *to)
 		timer_of_base_exit(&to->of_base);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(timer_of_init);
 
 /**
  * timer_of_cleanup - release timer_of resources
@@ -208,7 +209,7 @@ int __init timer_of_init(struct device_node *np, struct timer_of *to)
  * Release the resources that has been used in timer_of_init().
  * This function should be called in init error cases
  */
-void __init timer_of_cleanup(struct timer_of *to)
+void timer_of_cleanup(struct timer_of *to)
 {
 	if (to->flags & TIMER_OF_IRQ)
 		timer_of_irq_exit(&to->of_irq);
@@ -219,3 +220,4 @@ void __init timer_of_cleanup(struct timer_of *to)
 	if (to->flags & TIMER_OF_BASE)
 		timer_of_base_exit(&to->of_base);
 }
+EXPORT_SYMBOL_GPL(timer_of_cleanup);
diff --git a/drivers/clocksource/timer-of.h b/drivers/clocksource/timer-of.h
index 01a2c6b7db06..74a632b85b47 100644
--- a/drivers/clocksource/timer-of.h
+++ b/drivers/clocksource/timer-of.h
@@ -65,9 +65,8 @@ static inline unsigned long timer_of_period(struct timer_of *to)
 	return to->of_clk.period;
 }
 
-extern int __init timer_of_init(struct device_node *np,
-				struct timer_of *to);
+int timer_of_init(struct device_node *np, struct timer_of *to);
 
-extern void __init timer_of_cleanup(struct timer_of *to);
+void timer_of_cleanup(struct timer_of *to);
 
 #endif
-- 
2.43.0

[PATCH v1 4/7] clocksource/drivers/timer-probe: Add the module support for the TIMER_PDEV_DECLARE() macro

[Daniel Lezcano]

A driver using the macro TIMER_PDEV_DECLARE can now be compiled as a
module. When it is the case the TIMER_PDEV_DECLARE() macro will add
module_platform_driver() and MODULE_DEVICE_TABLE() automatically.

However if the early timer initialization is needed in place of the
module init section like what we have now, we should enable
CONFIG_EARLY_TIMER.

When all drivers will be converted to TIMER_PDEV_DECLARE(), the
TIMER_OF_DECLARE() can be removed and we will end up with the
following configuration:

 * On ARM architecture, we enable automatically CONFIG_EARLY_TIMER, no
   timer can be compiled as a module

 * On ARM64 architecture, we can enable as a module, otherwise it will
   be compiled-in. The CONFIG_EARLY_TIMER is not needed on this arch
   because the architected timers are always present

 * On other architecture, that needs to be defined but I suspect we
   have the same scheme

Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
---
 drivers/clocksource/Kconfig       |  7 ++++++-
 drivers/clocksource/timer-probe.c |  3 +++
 include/linux/clocksource.h       | 12 +++++++++++-
 3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index fd9112706545..ee2372f21e78 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -2,6 +2,11 @@
 menu "Clock Source drivers"
 	depends on GENERIC_CLOCKEVENTS
 
+config EARLY_TIMER
+        bool "Early driver initialization"
+	help
+	  Enables early timer driver loading
+
 config TIMER_OF
 	bool
 	select TIMER_PROBE
@@ -100,7 +105,7 @@ config IXP4XX_TIMER
 	  Enables support for the Intel XScale IXP4xx SoC timer.
 
 config ROCKCHIP_TIMER
-	bool "Rockchip timer driver" if COMPILE_TEST
+        bool "Rockchip timer driver" if COMPILE_TEST
 	depends on ARM || ARM64
 	select TIMER_OF
 	select CLKSRC_MMIO
diff --git a/drivers/clocksource/timer-probe.c b/drivers/clocksource/timer-probe.c
index cdaceb68d356..0fc582e4afde 100644
--- a/drivers/clocksource/timer-probe.c
+++ b/drivers/clocksource/timer-probe.c
@@ -84,6 +84,9 @@ static int __init timer_pdev_probe(void)
 {
 	struct platform_driver **drv;
 
+	if (!IS_ENABLED(CONFIG_EARLY_TIMER))
+		return 0;
+
 	for_each_pdev_timer_table(drv)
 		__timer_pdev_probe(*drv);
 
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 6e05b78e64b8..6b09fe67d37f 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -299,7 +299,7 @@ static inline void timer_probe(void) {}
 extern struct platform_driver *__pdev_timer_table[];
 extern struct platform_driver *__pdev_timer_table_end[];
 
-#define TIMER_PDEV_DECLARE(__name, __probe, __remove, __match)		\
+#define __TIMER_PDEV_DECLARE(__name, __probe, __remove, __match)	\
 	static struct platform_driver __pdev_timer_table_entry_##__name = { \
 		.probe = __probe,					\
 		.remove = __remove,					\
@@ -311,6 +311,16 @@ extern struct platform_driver *__pdev_timer_table_end[];
 	static struct platform_driver *___pdev_timer_table_entry_##__name \
 	__used __section("__pdev_timer_table") = &__pdev_timer_table_entry_##__name
 
+#if !defined(CONFIG_EARLY_TIMER) || defined(MODULE)
+#define TIMER_PDEV_DECLARE(__name, __probe, __remove, __match)		\
+	MODULE_DEVICE_TABLE(of, __match);				\
+	__TIMER_PDEV_DECLARE(__name, __probe, __remove, __match);	\
+	module_platform_driver(__pdev_timer_table_entry_##__name);
+#else
+#define TIMER_PDEV_DECLARE(__name, __probe, __remove, __match)		\
+	__TIMER_PDEV_DECLARE(__name, __probe, __remove, __match)
+#endif
+
 #define for_each_pdev_timer_table(__pdev)     \
 	for (__pdev = __pdev_timer_table;     \
 	     __pdev < __pdev_timer_table_end; \
-- 
2.43.0

[PATCH v1 5/7] clocksource/drivers/rockchip: Use the TIMER_PDEV_DECLARE() macro

[Daniel Lezcano]

The previous changes introduced the TIMER_PDEV_DECLARE() macro which
allows to use the platform driver to initialize a timer driver with
the benefit of having the devres to rollback automatically in case of
error.

Use this macro and change the function to rely on the devm_ variants,
allowing to cleanup the code.

Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
---
 drivers/clocksource/timer-rockchip.c | 99 ++++++++++------------------
 1 file changed, 34 insertions(+), 65 deletions(-)

diff --git a/drivers/clocksource/timer-rockchip.c b/drivers/clocksource/timer-rockchip.c
index 540a16667145..486bbffba464 100644
--- a/drivers/clocksource/timer-rockchip.c
+++ b/drivers/clocksource/timer-rockchip.c
@@ -124,18 +124,18 @@ static u64 notrace rk_timer_sched_read(void)
 	return ~readl_relaxed(rk_clksrc->base + TIMER_CURRENT_VALUE0);
 }
 
-static int __init
-rk_timer_probe(struct rk_timer *timer, struct device_node *np)
+static int rk_timer_init(struct rk_timer *timer, struct device *dev)
 {
+	struct device_node *np = dev->of_node;
 	struct clk *timer_clk;
 	struct clk *pclk;
-	int ret = -EINVAL, irq;
+	int irq;
 	u32 ctrl_reg = TIMER_CONTROL_REG3288;
 
-	timer->base = of_iomap(np, 0);
-	if (!timer->base) {
+	timer->base = devm_of_iomap(dev, np, 0, NULL);
+	if (IS_ERR(timer->base)) {
 		pr_err("Failed to get base address for '%s'\n", TIMER_NAME);
-		return -ENXIO;
+		return PTR_ERR(timer->base);
 	}
 
 	if (of_device_is_compatible(np, "rockchip,rk3399-timer"))
@@ -143,31 +143,17 @@ rk_timer_probe(struct rk_timer *timer, struct device_node *np)
 
 	timer->ctrl = timer->base + ctrl_reg;
 
-	pclk = of_clk_get_by_name(np, "pclk");
+	pclk = devm_clk_get_enabled(dev, "pclk");
 	if (IS_ERR(pclk)) {
-		ret = PTR_ERR(pclk);
 		pr_err("Failed to get pclk for '%s'\n", TIMER_NAME);
-		goto out_unmap;
-	}
-
-	ret = clk_prepare_enable(pclk);
-	if (ret) {
-		pr_err("Failed to enable pclk for '%s'\n", TIMER_NAME);
-		goto out_unmap;
+		return PTR_ERR(pclk);
 	}
 	timer->pclk = pclk;
 
-	timer_clk = of_clk_get_by_name(np, "timer");
+	timer_clk = devm_clk_get_enabled(dev, "timer");
 	if (IS_ERR(timer_clk)) {
-		ret = PTR_ERR(timer_clk);
 		pr_err("Failed to get timer clock for '%s'\n", TIMER_NAME);
-		goto out_timer_clk;
-	}
-
-	ret = clk_prepare_enable(timer_clk);
-	if (ret) {
-		pr_err("Failed to enable timer clock\n");
-		goto out_timer_clk;
+		return PTR_ERR(timer_clk);
 	}
 	timer->clk = timer_clk;
 
@@ -175,47 +161,32 @@ rk_timer_probe(struct rk_timer *timer, struct device_node *np)
 
 	irq = irq_of_parse_and_map(np, 0);
 	if (!irq) {
-		ret = -EINVAL;
 		pr_err("Failed to map interrupts for '%s'\n", TIMER_NAME);
-		goto out_irq;
+		return -EINVAL;
 	}
 	timer->irq = irq;
 
 	rk_timer_interrupt_clear(timer);
 	rk_timer_disable(timer);
-	return 0;
-
-out_irq:
-	clk_disable_unprepare(timer_clk);
-out_timer_clk:
-	clk_disable_unprepare(pclk);
-out_unmap:
-	iounmap(timer->base);
-
-	return ret;
-}
 
-static void __init rk_timer_cleanup(struct rk_timer *timer)
-{
-	clk_disable_unprepare(timer->clk);
-	clk_disable_unprepare(timer->pclk);
-	iounmap(timer->base);
+	return 0;
 }
 
-static int __init rk_clkevt_init(struct device_node *np)
+static int rk_clkevt_init(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct clock_event_device *ce;
 	int ret = -EINVAL;
 
-	rk_clkevt = kzalloc_obj(struct rk_clkevt);
+	rk_clkevt = devm_kzalloc(dev, sizeof(*rk_clkevt), GFP_KERNEL);
 	if (!rk_clkevt) {
 		ret = -ENOMEM;
 		goto out;
 	}
 
-	ret = rk_timer_probe(&rk_clkevt->timer, np);
+	ret = rk_timer_init(&rk_clkevt->timer, dev);
 	if (ret)
-		goto out_probe;
+		goto out;
 
 	ce = &rk_clkevt->ce;
 	ce->name = TIMER_NAME;
@@ -233,36 +204,33 @@ static int __init rk_clkevt_init(struct device_node *np)
 	if (ret) {
 		pr_err("Failed to initialize '%s': %d\n",
 			TIMER_NAME, ret);
-		goto out_irq;
+		goto out;
 	}
 
 	clockevents_config_and_register(&rk_clkevt->ce,
 					rk_clkevt->timer.freq, 1, UINT_MAX);
 	return 0;
 
-out_irq:
-	rk_timer_cleanup(&rk_clkevt->timer);
-out_probe:
-	kfree(rk_clkevt);
 out:
 	/* Leave rk_clkevt not NULL to prevent future init */
 	rk_clkevt = ERR_PTR(ret);
 	return ret;
 }
 
-static int __init rk_clksrc_init(struct device_node *np)
+static int rk_clksrc_init(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	int ret = -EINVAL;
 
-	rk_clksrc = kzalloc_obj(struct rk_timer);
+	rk_clksrc = devm_kzalloc(dev, sizeof(*rk_clksrc), GFP_KERNEL);
 	if (!rk_clksrc) {
 		ret = -ENOMEM;
 		goto out;
 	}
 
-	ret = rk_timer_probe(rk_clksrc, np);
+	ret = rk_timer_init(rk_clksrc, dev);
 	if (ret)
-		goto out_probe;
+		goto out;
 
 	rk_timer_update_counter(UINT_MAX, rk_clksrc);
 	rk_timer_enable(rk_clksrc, 0);
@@ -272,33 +240,34 @@ static int __init rk_clksrc_init(struct device_node *np)
 		clocksource_mmio_readl_down);
 	if (ret) {
 		pr_err("Failed to register clocksource\n");
-		goto out_clocksource;
+		goto out;
 	}
 
 	sched_clock_register(rk_timer_sched_read, 32, rk_clksrc->freq);
 	return 0;
 
-out_clocksource:
-	rk_timer_cleanup(rk_clksrc);
-out_probe:
-	kfree(rk_clksrc);
 out:
 	/* Leave rk_clksrc not NULL to prevent future init */
 	rk_clksrc = ERR_PTR(ret);
 	return ret;
 }
 
-static int __init rk_timer_init(struct device_node *np)
+static int rk_timer_probe(struct platform_device *pdev)
 {
 	if (!rk_clkevt)
-		return rk_clkevt_init(np);
+		return rk_clkevt_init(pdev);
 
 	if (!rk_clksrc)
-		return rk_clksrc_init(np);
+		return rk_clksrc_init(pdev);
 
 	pr_err("Too many timer definitions for '%s'\n", TIMER_NAME);
 	return -EINVAL;
 }
 
-TIMER_OF_DECLARE(rk3288_timer, "rockchip,rk3288-timer", rk_timer_init);
-TIMER_OF_DECLARE(rk3399_timer, "rockchip,rk3399-timer", rk_timer_init);
+static const struct of_device_id rk_timer_match_table[] = {
+	{ .compatible = "rockchip,rk3288-timer" },
+	{ .compatible = "rockchip,rk3399-timer" },
+	{ /* sentinel */ }
+};
+
+TIMER_PDEV_DECLARE(rk_timer, rk_timer_probe, NULL, rk_timer_match_table);
-- 
2.43.0

[PATCH v1 5/7] clocksource/drivers/timer-probe: Add the module support for the TIMER_PDEV_DECLARE() macro

[Daniel Lezcano]

A driver using the macro TIMER_PDEV_DECLARE can now be compiled as a
module. When it is the case the TIMER_PDEV_DECLARE() macro will add
module_platform_driver() and MODULE_DEVICE_TABLE() automatically.

However if the early timer initialization is needed in place of the
module init section like what we have now, we should enable
CONFIG_EARLY_TIMER.

When all drivers will be converted to TIMER_PDEV_DECLARE(), the
TIMER_OF_DECLARE() can be removed and we will end up with the
following configuration:

 * On ARM architecture, we enable automatically CONFIG_EARLY_TIMER, no
   timer can be compiled as a module

 * On ARM64 architecture, we can enable as a module, otherwise it will
   be compiled-in. The CONFIG_EARLY_TIMER is not needed on this arch
   because the architected timers are always present

 * On other architecture, that needs to be defined but I suspect we
   have the same scheme

Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
---
 drivers/clocksource/Kconfig       |  7 ++++++-
 drivers/clocksource/timer-probe.c |  3 +++
 include/linux/clocksource.h       | 12 +++++++++++-
 3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index fd9112706545..ee2372f21e78 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -2,6 +2,11 @@
 menu "Clock Source drivers"
 	depends on GENERIC_CLOCKEVENTS
 
+config EARLY_TIMER
+        bool "Early driver initialization"
+	help
+	  Enables early timer driver loading
+
 config TIMER_OF
 	bool
 	select TIMER_PROBE
@@ -100,7 +105,7 @@ config IXP4XX_TIMER
 	  Enables support for the Intel XScale IXP4xx SoC timer.
 
 config ROCKCHIP_TIMER
-	bool "Rockchip timer driver" if COMPILE_TEST
+        bool "Rockchip timer driver" if COMPILE_TEST
 	depends on ARM || ARM64
 	select TIMER_OF
 	select CLKSRC_MMIO
diff --git a/drivers/clocksource/timer-probe.c b/drivers/clocksource/timer-probe.c
index cdaceb68d356..0fc582e4afde 100644
--- a/drivers/clocksource/timer-probe.c
+++ b/drivers/clocksource/timer-probe.c
@@ -84,6 +84,9 @@ static int __init timer_pdev_probe(void)
 {
 	struct platform_driver **drv;
 
+	if (!IS_ENABLED(CONFIG_EARLY_TIMER))
+		return 0;
+
 	for_each_pdev_timer_table(drv)
 		__timer_pdev_probe(*drv);
 
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 6e05b78e64b8..6b09fe67d37f 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -299,7 +299,7 @@ static inline void timer_probe(void) {}
 extern struct platform_driver *__pdev_timer_table[];
 extern struct platform_driver *__pdev_timer_table_end[];
 
-#define TIMER_PDEV_DECLARE(__name, __probe, __remove, __match)		\
+#define __TIMER_PDEV_DECLARE(__name, __probe, __remove, __match)	\
 	static struct platform_driver __pdev_timer_table_entry_##__name = { \
 		.probe = __probe,					\
 		.remove = __remove,					\
@@ -311,6 +311,16 @@ extern struct platform_driver *__pdev_timer_table_end[];
 	static struct platform_driver *___pdev_timer_table_entry_##__name \
 	__used __section("__pdev_timer_table") = &__pdev_timer_table_entry_##__name
 
+#if !defined(CONFIG_EARLY_TIMER) || defined(MODULE)
+#define TIMER_PDEV_DECLARE(__name, __probe, __remove, __match)		\
+	MODULE_DEVICE_TABLE(of, __match);				\
+	__TIMER_PDEV_DECLARE(__name, __probe, __remove, __match);	\
+	module_platform_driver(__pdev_timer_table_entry_##__name);
+#else
+#define TIMER_PDEV_DECLARE(__name, __probe, __remove, __match)		\
+	__TIMER_PDEV_DECLARE(__name, __probe, __remove, __match)
+#endif
+
 #define for_each_pdev_timer_table(__pdev)     \
 	for (__pdev = __pdev_timer_table;     \
 	     __pdev < __pdev_timer_table_end; \
-- 
2.43.0

[PATCH v1 6/7] clocksource/drivers/rockchip: Add rockchip timer module support

[Daniel Lezcano]

Now the TIMER_PDEV_DECLARE() allows the driver to be compiled as a
module. Add the MODULE_DESCRIPTION and the MODULE_LICENSE left for the
one converting the driver as a module.

Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
---
 drivers/clocksource/timer-rockchip.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/clocksource/timer-rockchip.c b/drivers/clocksource/timer-rockchip.c
index 486bbffba464..61433b295882 100644
--- a/drivers/clocksource/timer-rockchip.c
+++ b/drivers/clocksource/timer-rockchip.c
@@ -271,3 +271,5 @@ static const struct of_device_id rk_timer_match_table[] = {
 };
 
 TIMER_PDEV_DECLARE(rk_timer, rk_timer_probe, NULL, rk_timer_match_table);
+MODULE_DESCRIPTION("Rockchip timer driver");
+MODULE_LICENSE("GPL");
-- 
2.43.0

[PATCH v1 7/7] clocksource/drivers/mediatek: Convert to module support

[Daniel Lezcano]

Now the TIMER_PDEV_DECLARE() allows the driver to be compiled as a
module. Add the MODULE_DESCRIPTION and the MODULE_LICENSE left for the
one converting the driver as a module.

Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
---
 drivers/clocksource/timer-mediatek.c | 29 ++++++++++++++++++++++------
 1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/drivers/clocksource/timer-mediatek.c b/drivers/clocksource/timer-mediatek.c
index 7bcb4a3f26fb..f5de5f397730 100644
--- a/drivers/clocksource/timer-mediatek.c
+++ b/drivers/clocksource/timer-mediatek.c
@@ -215,8 +215,7 @@ static irqreturn_t mtk_gpt_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static void
-__init mtk_gpt_setup(struct timer_of *to, u8 timer, u8 option)
+static void mtk_gpt_setup(struct timer_of *to, u8 timer, u8 option)
 {
 	writel(GPT_CTRL_CLEAR | GPT_CTRL_DISABLE,
 	       timer_of_base(to) + GPT_CTRL_REG(timer));
@@ -281,7 +280,7 @@ static struct timer_of to = {
 	},
 };
 
-static int __init mtk_syst_init(struct device_node *node)
+static int mtk_syst_init(struct device_node *node)
 {
 	int ret;
 
@@ -302,7 +301,7 @@ static int __init mtk_syst_init(struct device_node *node)
 	return 0;
 }
 
-static int __init mtk_gpt_init(struct device_node *node)
+static int mtk_gpt_init(struct device_node *node)
 {
 	int ret;
 
@@ -337,5 +336,23 @@ static int __init mtk_gpt_init(struct device_node *node)
 
 	return 0;
 }
-TIMER_OF_DECLARE(mtk_mt6577, "mediatek,mt6577-timer", mtk_gpt_init);
-TIMER_OF_DECLARE(mtk_mt6765, "mediatek,mt6765-timer", mtk_syst_init);
+
+static int mtk_timer_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int (*probe_func)(struct device_node *node);
+
+	probe_func = of_device_get_match_data(&pdev->dev);
+
+	return probe_func(np);
+}
+
+static const struct of_device_id mtk_timer_match_table[] = {
+	{ .compatible =  "mediatek,mt6577-timer", .data = mtk_gpt_init },
+	{ .compatible =  "mediatek,mt6765-timer", .data = mtk_syst_init },
+	{ /* sentinel */ }
+};
+
+TIMER_PDEV_DECLARE(mtk_timer, mtk_timer_probe, NULL, mtk_timer_match_table);
+MODULE_DESCRIPTION("Mediatek timer driver");
+MODULE_LICENSE("GPL");
-- 
2.43.0

Re: [PATCH v1 0/7] Timer driver module support

[Daniel Lezcano]

On 3/27/26 18:55, Daniel Lezcano wrote:
> Converting the timer driver modules requires a particular care
> because, depending on the platform, that may be not supported.

Sorry this series has been corrupted with a previous draft series.

I'll resend.