init: remove the need for a dummy device pointer in SYS_INIT functions

The init infrastructure, found in `init.h`, is currently used by:

- `SYS_INIT`: to call functions before `main`
- `DEVICE_*`: to initialize devices

They are all sorted according to an initialization level + a priority.
`SYS_INIT` calls are really orthogonal to devices, however, the required
function signature requires a `const struct device *dev` as a first
argument. The only reason for that is because the same init machinery is
used by devices, so we have something like:

```c
struct init_entry {
	int (*init)(const struct device *dev);
	/* only set by DEVICE_*, otherwise NULL */
	const struct device *dev;
}
```

As a result, we end up with such weird/ugly pattern:

```c
static int my_init(const struct device *dev)
{
	/* always NULL! add ARG_UNUSED to avoid compiler warning */
	ARG_UNUSED(dev);
	...
}
```

This is really a result of poor internals isolation. This patch proposes
a to make init entries more flexible so that they can accept sytem
initialization calls like this:

```c
static int my_init(void)
{
	...
}
```

This is achieved using a union:

```c
union init_function {
	/* for SYS_INIT, used when init_entry.dev == NULL */
	int (*sys)(void);
	/* for DEVICE*, used when init_entry.dev != NULL */
	int (*dev)(const struct device *dev);
};

struct init_entry {
	/* stores init function (either for SYS_INIT or DEVICE*)
	union init_function init_fn;
	/* stores device pointer for DEVICE*, NULL for SYS_INIT. Allows
	 * to know which union entry to call.
	 */
	const struct device *dev;
}
```

This solution **does not increase ROM usage**, and allows to offer clean
public APIs for both SYS_INIT and DEVICE*. Note that however, init
machinery keeps a coupling with devices.

**NOTE**: This is a breaking change! All `SYS_INIT` functions will need
to be converted to the new signature. See the script offered in the
following commit.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>

init: convert SYS_INIT functions to the new signature

Conversion scripted using scripts/utils/migrate_sys_init.py.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>

manifest: update projects for SYS_INIT changes

Update modules with updated SYS_INIT calls:

- hal_ti
- lvgl
- sof
- TraceRecorderSource

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>

tests: devicetree: devices: adjust test

Adjust test according to the recently introduced SYS_INIT
infrastructure.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>

tests: kernel: threads: adjust SYS_INIT call

Adjust to the new signature: int (*init_fn)(void);

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>

Author: gmarull

arch/arc/core/arc_smp.c

@@ -145,9 +145,8 @@ void arch_sched_ipi(void)
 	}
 }
 
-static int arc_smp_init(const struct device *dev)
+static int arc_smp_init(void)
 {
-	ARG_UNUSED(dev);
 	struct arc_connect_bcr bcr;
 
 	/* necessary master core init */

arch/arc/core/cache.c

@@ -216,9 +216,8 @@ int arch_icache_flush_and_invd_range(void *addr, size_t size)
 	return -ENOTSUP;
 }
 
-static int init_dcache(const struct device *unused)
+static int init_dcache(void)
 {
-	ARG_UNUSED(unused);
 
 	arch_dcache_enable();
 

arch/arc/core/irq_offload.c

@@ -54,9 +54,8 @@ void arch_irq_offload(irq_offload_routine_t routine, const void *parameter)
 }
 
 /* need to be executed on every core in the system */
-int arc_irq_offload_init(const struct device *unused)
+int arc_irq_offload_init(void)
 {
-	ARG_UNUSED(unused);
 
 	IRQ_CONNECT(IRQ_OFFLOAD_LINE, IRQ_OFFLOAD_PRIO, arc_irq_offload_handler, NULL, 0);
 

arch/arc/core/mpu/arc_mpu_common_internal.h

@@ -238,9 +238,8 @@ int arc_core_mpu_buffer_validate(void *addr, size_t size, int write)
  * This function provides the default configuration mechanism for the Memory
  * Protection Unit (MPU).
  */
-static int arc_mpu_init(const struct device *arg)
+static int arc_mpu_init(void)
 {
-	ARG_UNUSED(arg);
 
 	uint32_t num_regions = get_num_regions();
 

arch/arc/core/mpu/arc_mpu_v4_internal.h

@@ -814,9 +814,8 @@ int arc_core_mpu_buffer_validate(void *addr, size_t size, int write)
  * This function provides the default configuration mechanism for the Memory
  * Protection Unit (MPU).
  */
-static int arc_mpu_init(const struct device *arg)
+static int arc_mpu_init(void)
 {
-	ARG_UNUSED(arg);
 	uint32_t num_regions;
 	uint32_t i;
 

arch/arc/core/secureshield/arc_sjli.c

@@ -48,7 +48,7 @@ static void sjli_table_init(void)
 /*
  * @brief initialization of secureshield related functions.
  */
-static int arc_secureshield_init(const struct device *arg)
+static int arc_secureshield_init(void)
 {
 	sjli_table_init();
 

arch/arm/core/aarch32/cortex_m/debug.c

@@ -58,9 +58,8 @@ BUILD_ASSERT(!(CONFIG_CORTEX_M_NULL_POINTER_EXCEPTION_PAGE_SIZE &
 	(CONFIG_CORTEX_M_NULL_POINTER_EXCEPTION_PAGE_SIZE - 1)),
 	"the size of the partition must be power of 2");
 
-static int z_arm_debug_enable_null_pointer_detection(const struct device *arg)
+static int z_arm_debug_enable_null_pointer_detection(void)
 {
-	ARG_UNUSED(arg);
 
 	z_arm_dwt_init();
 	z_arm_dwt_enable_debug_monitor();

arch/arm64/core/smp.c

@@ -226,9 +226,8 @@ void z_arm64_flush_fpu_ipi(unsigned int cpu)
 }
 #endif
 
-static int arm64_smp_init(const struct device *dev)
+static int arm64_smp_init(void)
 {
-	ARG_UNUSED(dev);
 
 	/*
 	 * SGI0 is use for sched ipi, this might be changed to use Kconfig

arch/arm64/core/xen/enlighten.c

@@ -42,9 +42,8 @@ static int xen_map_shared_info(const shared_info_t *shared_page)
 	return HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp);
 }
 
-static int xen_enlighten_init(const struct device *dev)
+static int xen_enlighten_init(void)
 {
-	ARG_UNUSED(dev);
 	int ret = 0;
 	shared_info_t *info = (shared_info_t *) shared_info_buf;
 

arch/riscv/core/smp.c

@@ -118,9 +118,8 @@ static void ipi_handler(const void *unused)
 #endif
 }
 
-static int riscv_smp_init(const struct device *dev)
+static int riscv_smp_init(void)
 {
-	ARG_UNUSED(dev);
 
 	IRQ_CONNECT(RISCV_MACHINE_SOFT_IRQ, 0, ipi_handler, NULL, 0);
 	irq_enable(RISCV_MACHINE_SOFT_IRQ);