[RESEND PATCH v3 0/3] Add module build support for timer driver

[RESEND PATCH v3 0/3] Add module build support for timer driver

[Chunyan Zhang]

From: Chunyan Zhang <chunyan.zhang@unisoc.com>

This patchset was based on the previous one [1], and add a
boilerplate macro for module build purpose according to comments
from Thomas Gleixner on the patch [2].

Also switch sprd timer driver to use the help macro to support
module build.

* Changes from v2:
- Define one macro TIMER_PLATFORM_DECLEAR() to replace the three ones in the v2;
- Use builtin_platform_driver() to replace module_platform_driver() to make sure
  unloading timer modules not supported;
- Add more description to explain that unloading is not supported.

* Changes from v1:
- Removed TIMER_OF_DECLARE() from timer-sprd.c, and removed ifdef;
- Rebased on v5.14-rc1.

[1] https://lkml.org/lkml/2020/3/24/72
[2] https://www.spinics.net/lists/arm-kernel/msg826631.html

Chunyan Zhang (2):
  clocksource/drivers/timer-of: Add a boilerplate macro for timer module
    driver
  clocksource/drivers/sprd: Add module support to Unisoc timer

Saravana Kannan (1):
  drivers/clocksource/timer-of: Remove __init markings

 drivers/clocksource/Kconfig      |  2 +-
 drivers/clocksource/timer-of.c   | 30 ++++++++++++++++++++++--------
 drivers/clocksource/timer-of.h   | 19 +++++++++++++++++--
 drivers/clocksource/timer-sprd.c | 18 +++++++++++++-----
 4 files changed, 53 insertions(+), 16 deletions(-)

-- 
2.25.1

[RESEND PATCH v3 1/3] drivers/clocksource/timer-of: Remove __init markings

[Chunyan Zhang]

From: Saravana Kannan <saravanak@google.com>

This allows timer drivers to be compiled as modules which can be a
platform-level devices, so the timer_of_init()/_cleanup() should able to
be called from platform_driver_register() which support deferred probing.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
---
 drivers/clocksource/timer-of.c | 17 +++++++++--------
 drivers/clocksource/timer-of.h |  4 ++--
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/clocksource/timer-of.c b/drivers/clocksource/timer-of.c
index 529cc6a51cdb..7f108978fd51 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);
 
@@ -47,7 +47,7 @@ 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,
+static int timer_of_irq_init(struct device_node *np,
 				    struct of_timer_irq *of_irq)
 {
 	int ret;
@@ -91,7 +91,7 @@ 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);
@@ -107,7 +107,7 @@ 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,
+static int timer_of_clk_init(struct device_node *np,
 				    struct of_timer_clk *of_clk)
 {
 	int ret;
@@ -146,12 +146,12 @@ 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,
+static int timer_of_base_init(struct device_node *np,
 				     struct of_timer_base *of_base)
 {
 	of_base->base = of_base->name ?
@@ -165,7 +165,7 @@ 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;
@@ -209,6 +209,7 @@ 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
@@ -217,7 +218,7 @@ 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);
diff --git a/drivers/clocksource/timer-of.h b/drivers/clocksource/timer-of.h
index a5478f3e8589..1b8cfac5900a 100644
--- a/drivers/clocksource/timer-of.h
+++ b/drivers/clocksource/timer-of.h
@@ -66,9 +66,9 @@ 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,
+extern int timer_of_init(struct device_node *np,
 				struct timer_of *to);
 
-extern void __init timer_of_cleanup(struct timer_of *to);
+extern void timer_of_cleanup(struct timer_of *to);
 
 #endif
-- 
2.25.1

[RESEND PATCH v3 2/3] clocksource/drivers/timer-of: Add a boilerplate macro for timer module driver

[Chunyan Zhang]

From: Chunyan Zhang <chunyan.zhang@unisoc.com>

To support module build, platform driver structs, .probe(), match table and
module macros need to be added to the timer driver. So this patch provides
a macro to take care of these things, and that would reduce the repeat
code lines in every sigle driver.

Since timer module should support loading only, we use
builtin_platform_driver() which doesn't include module_exit() to make
sure timer modules wouldn't be unloaded.

Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
---
 drivers/clocksource/timer-of.c | 13 +++++++++++++
 drivers/clocksource/timer-of.h | 15 +++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/drivers/clocksource/timer-of.c b/drivers/clocksource/timer-of.c
index 7f108978fd51..ecd7f7379400 100644
--- a/drivers/clocksource/timer-of.c
+++ b/drivers/clocksource/timer-of.c
@@ -8,7 +8,9 @@
 #include <linux/interrupt.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_device.h>
 #include <linux/of_irq.h>
+#include <linux/platform_device.h>
 #include <linux/slab.h>
 
 #include "timer-of.h"
@@ -229,3 +231,14 @@ void timer_of_cleanup(struct timer_of *to)
 	if (to->flags & TIMER_OF_BASE)
 		timer_of_base_exit(&to->of_base);
 }
+
+int platform_timer_probe(struct platform_device *pdev)
+{
+	int (*init_cb)(struct device_node *node);
+	struct device_node *np = pdev->dev.of_node;
+
+	init_cb = of_device_get_match_data(&pdev->dev);
+
+	return init_cb(np);
+}
+EXPORT_SYMBOL_GPL(platform_timer_probe);
diff --git a/drivers/clocksource/timer-of.h b/drivers/clocksource/timer-of.h
index 1b8cfac5900a..04a476da01bb 100644
--- a/drivers/clocksource/timer-of.h
+++ b/drivers/clocksource/timer-of.h
@@ -3,6 +3,7 @@
 #define __TIMER_OF_H__
 
 #include <linux/clockchips.h>
+#include <linux/platform_device.h>
 
 #define TIMER_OF_BASE	0x1
 #define TIMER_OF_CLOCK	0x2
@@ -71,4 +72,18 @@ extern int timer_of_init(struct device_node *np,
 
 extern void timer_of_cleanup(struct timer_of *to);
 
+extern int platform_timer_probe(struct platform_device *pdev);
+
+#define TIMER_PLATFORM_DECLEAR(desc, drv_name, table)		\
+MODULE_DEVICE_TABLE(of, table);					\
+static struct platform_driver drv_name##_driver = {		\
+	.probe  = platform_timer_probe,				\
+	.driver = {						\
+		.name = #drv_name,				\
+		.of_match_table = table,			\
+	},							\
+};								\
+builtin_platform_driver(drv_name##_driver);			\
+MODULE_DESCRIPTION(desc);					\
+MODULE_LICENSE("GPL")
 #endif
-- 
2.25.1

[RESEND PATCH v3 3/3] clocksource/drivers/sprd: Add module support to Unisoc timer

[Chunyan Zhang]

From: Chunyan Zhang <chunyan.zhang@unisoc.com>

Timers still have devices created for them. So, when compiling a timer
driver as a module, implement it as a normal platform device driver.

Original-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
---
 drivers/clocksource/Kconfig      |  2 +-
 drivers/clocksource/timer-sprd.c | 18 +++++++++++++-----
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 0f5e3983951a..901f54cebe92 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -462,7 +462,7 @@ config MTK_TIMER
 	  Support for Mediatek timer driver.
 
 config SPRD_TIMER
-	bool "Spreadtrum timer driver" if EXPERT
+	tristate "Spreadtrum timer driver" if EXPERT
 	depends on HAS_IOMEM
 	depends on (ARCH_SPRD || COMPILE_TEST)
 	default ARCH_SPRD
diff --git a/drivers/clocksource/timer-sprd.c b/drivers/clocksource/timer-sprd.c
index 430cb99d8d79..b29c48ef3ba5 100644
--- a/drivers/clocksource/timer-sprd.c
+++ b/drivers/clocksource/timer-sprd.c
@@ -5,6 +5,8 @@
 
 #include <linux/init.h>
 #include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
 
 #include "timer-of.h"
 
@@ -141,7 +143,7 @@ static struct timer_of to = {
 	},
 };
 
-static int __init sprd_timer_init(struct device_node *np)
+static int sprd_timer_init(struct device_node *np)
 {
 	int ret;
 
@@ -190,7 +192,7 @@ static struct clocksource suspend_clocksource = {
 	.flags	= CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_SUSPEND_NONSTOP,
 };
 
-static int __init sprd_suspend_timer_init(struct device_node *np)
+static int sprd_suspend_timer_init(struct device_node *np)
 {
 	int ret;
 
@@ -204,6 +206,12 @@ static int __init sprd_suspend_timer_init(struct device_node *np)
 	return 0;
 }
 
-TIMER_OF_DECLARE(sc9860_timer, "sprd,sc9860-timer", sprd_timer_init);
-TIMER_OF_DECLARE(sc9860_persistent_timer, "sprd,sc9860-suspend-timer",
-		 sprd_suspend_timer_init);
+static const struct of_device_id sc9860_timer_match_table[] = {
+	{ .compatible = "sprd,sc9860-timer",
+		.data = sprd_timer_init },
+	{ .compatible = "sprd,sc9860-suspend-timer",
+		.data = sprd_suspend_timer_init },
+	{},
+};
+TIMER_PLATFORM_DECLEAR("Unisoc broadcast timer module", sc9860_timer,
+		       sc9860_timer_match_table);
-- 
2.25.1