x86/platform/intel-mid: Fix RTC / WDT handling

Current RTC approach breaks some platforms. Rewrite it completely and make avaiable only for intended platforms.

Tested on Intel Merrifield, ASuS T100TA (normal and acpi=off cases).

Since v3:
- move to arch_initcall()
- do the same for watchdog registration code (new patch 4)

Since v2:
- add mp_map_gsi_to_irq() fix to the series as patch 1
- add patch 3
- rewrite RTC approach as another platform code for Intel MID

Andy Shevchenko (4):
x86/ioapic: Return suitable error code in mp_map_gsi_to_irq() x86/platform/intel-mid: Allocate RTC interrupt for Merrifield x86/platform/intel-mid: Don't shadow error code of mp_map_gsi_to_irq() x86/platform/intel-mid: Move watchdog registration to arch_initcall()

 arch/x86/kernel/apic/io_apic.c                     |  4 +-
 arch/x86/platform/intel-mid/device_libs/Makefile   |  1 +
 .../intel-mid/device_libs/platform_mrfld_rtc.c     | 48 ++++++++++++++++++++++
 .../intel-mid/device_libs/platform_mrfld_wdt.c     | 12 +++---
 arch/x86/platform/intel-mid/sfi.c                  | 14 -------
 5 files changed, 57 insertions(+), 22 deletions(-)
 create mode 100644 arch/x86/platform/intel-mid/device_libs/platform_mrfld_rtc.c

2.11.0

mp_map_gsi_to_irq() in some cases might return legacy -1, which would be wrongly interpreted as -EPERM.

Correct those cases to return proper error code.

---
 arch/x86/kernel/apic/io_apic.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

index 945e512a112a..f62c38d325da 100644
@@ -1107,12 +1107,12 @@ int mp_map_gsi_to_irq(u32 gsi, unsigned int flags, struct irq_alloc_info *info)
 
 	ioapic = mp_find_ioapic(gsi);
 	if (ioapic < 0)
-		return -1;
+		return -ENODEV;
 
 	pin = mp_find_ioapic_pin(ioapic, gsi);
 	idx = find_irq_entry(ioapic, pin, mp_INT);
 	if ((flags & IOAPIC_MAP_CHECK) && idx < 0)
-		return -1;
+		return -ENODEV;
 
 	return mp_map_pin_to_irq(gsi, idx, ioapic, pin, flags, info);
 }

2.11.0

Legacy RTC requires interrupt line 8 to be dedicated for it. On Intel MID platforms the legacy PIC is absent and in order to make RTC work we need to allocate interrupt separately.

Current solution brought by the commit:

de1c2540aa4f ("x86/platform/intel-mid: Enable RTC on Intel Merrifield")

does it in a wrong place, and since it's done unconditionally for all x86 devices, some of them, e.g. PNP based, might get it wrong -- at the beginning x86_platform.legacy.rtc flag is set for all x86 devices.

Move intel_mid_legacy_rtc_init() to its own module and call it before x86 RTC CMOS initialization.

---
 arch/x86/platform/intel-mid/device_libs/Makefile   |  1 +
 .../intel-mid/device_libs/platform_mrfld_rtc.c     | 48 ++++++++++++++++++++++
 arch/x86/platform/intel-mid/sfi.c                  | 14 -------
 3 files changed, 49 insertions(+), 14 deletions(-)
 create mode 100644 arch/x86/platform/intel-mid/device_libs/platform_mrfld_rtc.c

index d4af7785844e..a7dbec4dce27 100644
@@ -26,4 +26,5 @@ obj-$(subst m,y,$(CONFIG_GPIO_PCA953X)) += platform_pcal9555a.o
 obj-$(subst m,y,$(CONFIG_GPIO_PCA953X)) += platform_tca6416.o
 # MISC Devices
 obj-$(subst m,y,$(CONFIG_KEYBOARD_GPIO)) += platform_gpio_keys.o
+obj-$(subst m,y,$(CONFIG_RTC_DRV_CMOS)) += platform_mrfld_rtc.o
 obj-$(subst m,y,$(CONFIG_INTEL_MID_WATCHDOG)) += platform_mrfld_wdt.o

index e4d4cabbb370..19b43e3a9f0f 100644
@@ -41,7 +41,6 @@
 #include <asm/intel_scu_ipc.h>
 #include <asm/apb_timer.h>
 #include <asm/reboot.h>
-#include <asm/time.h>
 
 #define	SFI_SIG_OEM0	"OEM0"
 #define MAX_IPCDEVS	24

@@ -540,21 +539,8 @@ static int __init sfi_parse_devs(struct sfi_table_header *table)
 	return 0;
 }
 
-static int __init intel_mid_legacy_rtc_init(void)
-{
-	struct irq_alloc_info info;
-
-	if (!x86_platform.legacy.rtc)
-		return -ENODEV;
-
-	ioapic_set_alloc_attr(&info, NUMA_NO_NODE, 1, 0);
-	return mp_map_gsi_to_irq(RTC_IRQ, IOAPIC_MAP_ALLOC, &info);
-}
-
 static int __init intel_mid_platform_init(void)
 {
-	intel_mid_legacy_rtc_init();
-
 	sfi_table_parse(SFI_SIG_GPIO, NULL, NULL, sfi_parse_gpio);
 	sfi_table_parse(SFI_SIG_DEVS, NULL, NULL, sfi_parse_devs);
 	return 0;

2.11.0

When call mp_map_gsi_to_irq() and return its error code do not shadow it. Note that 0 is not an error.

---
 arch/x86/platform/intel-mid/device_libs/platform_mrfld_wdt.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

index 3f1f1c77d090..8a10a56f2840 100644
@@ -28,9 +28,9 @@ static struct platform_device wdt_dev = {
 
 static int tangier_probe(struct platform_device *pdev)
 {
-	int gsi;
 	struct irq_alloc_info info;
 	struct intel_mid_wdt_pdata *pdata = pdev->dev.platform_data;
+	int gsi, irq;
 
 	if (!pdata)
 		return -EINVAL;

@@ -38,10 +38,10 @@ static int tangier_probe(struct platform_device *pdev)
 	/* IOAPIC builds identity mapping between GSI and IRQ on MID */
 	gsi = pdata->irq;
 	ioapic_set_alloc_attr(&info, cpu_to_node(0), 1, 0);
-	if (mp_map_gsi_to_irq(gsi, IOAPIC_MAP_ALLOC, &info) <= 0) {
-		dev_warn(&pdev->dev, "cannot find interrupt %d in ioapic\n",
-			 gsi);
-		return -EINVAL;
+	irq = mp_map_gsi_to_irq(gsi, IOAPIC_MAP_ALLOC, &info);
+	if (irq < 0) {
+		dev_warn(&pdev->dev, "cannot find interrupt %d in ioapic\n", gsi);
+		return irq;
 	}
 
 	return 0;

2.11.0

There is no need to choose a random initcall level for certainly architecture dependent code.

Move watchdog registration to arch_initcall() from rootfs_initcall().

---
 arch/x86/platform/intel-mid/device_libs/platform_mrfld_wdt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 8a10a56f2840..86edd1e941eb 100644
@@ -82,4 +82,4 @@ static int __init register_mid_wdt(void)
 
 	return 0;
 }
-rootfs_initcall(register_mid_wdt);
+arch_initcall(register_mid_wdt);

2.11.0