Re: [PATCH 03/10] drm/privacy-screen: Add X86 specific arch init code

2021-11-17 Thread Hans de Goede 
Hi Rajat,

On 11/17/21 15:13, Rajat Jain wrote:
> Hello Hans,
> 
> On Tue, Oct 5, 2021 at 1:23 PM Hans de Goede  wrote:
>>
>> Add X86 specific arch init code, which fills the privacy-screen lookup
>> table by checking for various vendor specific ACPI interfaces for
>> controlling the privacy-screen.
>>
>> This initial version only checks for the Lenovo Thinkpad specific ACPI
>> methods for privacy-screen control.
>>
>> Reviewed-by: Emil Velikov 
>> Reviewed-by: Lyude Paul 
>> Signed-off-by: Hans de Goede 
>> ---
>>  drivers/gpu/drm/Makefile |  2 +-
>>  drivers/gpu/drm/drm_privacy_screen_x86.c | 86 
>>  include/drm/drm_privacy_screen_machine.h |  5 ++
>>  3 files changed, 92 insertions(+), 1 deletion(-)
>>  create mode 100644 drivers/gpu/drm/drm_privacy_screen_x86.c
>>
>> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
>> index 788fc37096f6..12997ca5670d 100644
>> --- a/drivers/gpu/drm/Makefile
>> +++ b/drivers/gpu/drm/Makefile
>> @@ -32,7 +32,7 @@ drm-$(CONFIG_OF) += drm_of.o
>>  drm-$(CONFIG_PCI) += drm_pci.o
>>  drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o
>>  drm-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
>> -drm-$(CONFIG_DRM_PRIVACY_SCREEN) += drm_privacy_screen.o
>> +drm-$(CONFIG_DRM_PRIVACY_SCREEN) += drm_privacy_screen.o 
>> drm_privacy_screen_x86.o
>>
>>  obj-$(CONFIG_DRM_DP_AUX_BUS) += drm_dp_aux_bus.o
>>
>> diff --git a/drivers/gpu/drm/drm_privacy_screen_x86.c 
>> b/drivers/gpu/drm/drm_privacy_screen_x86.c
>> new file mode 100644
>> index ..a2cafb294ca6
>> --- /dev/null
>> +++ b/drivers/gpu/drm/drm_privacy_screen_x86.c
>> @@ -0,0 +1,86 @@
>> +// SPDX-License-Identifier: MIT
>> +/*
>> + * Copyright (C) 2020 Red Hat, Inc.
>> + *
>> + * Authors:
>> + * Hans de Goede 
>> + */
>> +
>> +#include 
>> +#include 
>> +
>> +#ifdef CONFIG_X86
>> +static struct drm_privacy_screen_lookup arch_lookup;
>> +
>> +struct arch_init_data {
>> +   struct drm_privacy_screen_lookup lookup;
>> +   bool (*detect)(void);
>> +};
>> +
>> +#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
>> +static acpi_status __init acpi_set_handle(acpi_handle handle, u32 level,
>> + void *context, void **return_value)
>> +{
>> +   *(acpi_handle *)return_value = handle;
>> +   return AE_CTRL_TERMINATE;
>> +}
>> +
>> +static bool __init detect_thinkpad_privacy_screen(void)
>> +{
>> +   union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
>> +   struct acpi_object_list args = { .count = 1, .pointer = &obj, };
>> +   acpi_handle ec_handle = NULL;
>> +   unsigned long long output;
>> +   acpi_status status;
>> +
>> +   /* Get embedded-controller handle */
>> +   status = acpi_get_devices("PNP0C09", acpi_set_handle, NULL, 
>> &ec_handle);
>> +   if (ACPI_FAILURE(status) || !ec_handle)
>> +   return false;
>> +
>> +   /* And call the privacy-screen get-status method */
>> +   status = acpi_evaluate_integer(ec_handle, "HKEY.GSSS", &args, 
>> &output);
>> +   if (ACPI_FAILURE(status))
>> +   return false;
>> +
>> +   return (output & 0x1) ? true : false;
>> +}
>> +#endif
>> +
>> +static const struct arch_init_data arch_init_data[] __initconst = {
>> +#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
>> +   {
>> +   .lookup = {
>> +   .dev_id = NULL,
>> +   .con_id = NULL,
>> +   .provider = "privacy_screen-thinkpad_acpi",
>> +   },
>> +   .detect = detect_thinkpad_privacy_screen,
>> +   },
>> +#endif
>> +};
> 
> As I'm trying to add privacy-screen support for my platform, I'm
> trying to understand if my platform needs to make an entry in this
> static list.
> 
> Do I understand it right that the reason you needed this static list
> (and this whole file really), instead of just doing a
> drm_privacy_screen_lookup_add() in the platform code in
> thinkpad_acpi.c, was because that code was executed AFTER the
> drm_connectors had already initialized> 
> In other words, the privacy-screen providers (platform code) need to
> register a privacy-screen and a lookup structure, BEFORE the drm
> connectors are initialized. If the platform code that provides a
> privacy-screen is executed AFTER the drm-connector initializes, then
> we need an entry in this static list, so that the drm probe (for i915
> atleast) is DEFERRED until the privacy-screen provider registers the
> privacy-screen?
> 
> OTOH, if the platform can register a privacy-screen and a lookup
> function (via drm_privacy_screen_lookup_add()) BEFORE drm probe, then
> I do not need an entry in this static list.
> 
> Is this correct understanding?

Yes, this is all here to deal with probe-ordering.

On a platform where the link between connectors and device-tree
is available in something like devicetree this all becomes
much easier.

The i915 code does a:

   privacy_screen = drm_privacy_screen_get(

[PATCH 03/10] drm/privacy-screen: Add X86 specific arch init code

2021-10-05 Thread Hans de Goede 
Add X86 specific arch init code, which fills the privacy-screen lookup
table by checking for various vendor specific ACPI interfaces for
controlling the privacy-screen.

This initial version only checks for the Lenovo Thinkpad specific ACPI
methods for privacy-screen control.

Reviewed-by: Emil Velikov 
Reviewed-by: Lyude Paul 
Signed-off-by: Hans de Goede 
---
 drivers/gpu/drm/Makefile |  2 +-
 drivers/gpu/drm/drm_privacy_screen_x86.c | 86 
 include/drm/drm_privacy_screen_machine.h |  5 ++
 3 files changed, 92 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/drm_privacy_screen_x86.c

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 788fc37096f6..12997ca5670d 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -32,7 +32,7 @@ drm-$(CONFIG_OF) += drm_of.o
 drm-$(CONFIG_PCI) += drm_pci.o
 drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o
 drm-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
-drm-$(CONFIG_DRM_PRIVACY_SCREEN) += drm_privacy_screen.o
+drm-$(CONFIG_DRM_PRIVACY_SCREEN) += drm_privacy_screen.o 
drm_privacy_screen_x86.o
 
 obj-$(CONFIG_DRM_DP_AUX_BUS) += drm_dp_aux_bus.o
 
diff --git a/drivers/gpu/drm/drm_privacy_screen_x86.c 
b/drivers/gpu/drm/drm_privacy_screen_x86.c
new file mode 100644
index ..a2cafb294ca6
--- /dev/null
+++ b/drivers/gpu/drm/drm_privacy_screen_x86.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright (C) 2020 Red Hat, Inc.
+ *
+ * Authors:
+ * Hans de Goede 
+ */
+
+#include 
+#include 
+
+#ifdef CONFIG_X86
+static struct drm_privacy_screen_lookup arch_lookup;
+
+struct arch_init_data {
+   struct drm_privacy_screen_lookup lookup;
+   bool (*detect)(void);
+};
+
+#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
+static acpi_status __init acpi_set_handle(acpi_handle handle, u32 level,
+ void *context, void **return_value)
+{
+   *(acpi_handle *)return_value = handle;
+   return AE_CTRL_TERMINATE;
+}
+
+static bool __init detect_thinkpad_privacy_screen(void)
+{
+   union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
+   struct acpi_object_list args = { .count = 1, .pointer = &obj, };
+   acpi_handle ec_handle = NULL;
+   unsigned long long output;
+   acpi_status status;
+
+   /* Get embedded-controller handle */
+   status = acpi_get_devices("PNP0C09", acpi_set_handle, NULL, &ec_handle);
+   if (ACPI_FAILURE(status) || !ec_handle)
+   return false;
+
+   /* And call the privacy-screen get-status method */
+   status = acpi_evaluate_integer(ec_handle, "HKEY.GSSS", &args, &output);
+   if (ACPI_FAILURE(status))
+   return false;
+
+   return (output & 0x1) ? true : false;
+}
+#endif
+
+static const struct arch_init_data arch_init_data[] __initconst = {
+#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
+   {
+   .lookup = {
+   .dev_id = NULL,
+   .con_id = NULL,
+   .provider = "privacy_screen-thinkpad_acpi",
+   },
+   .detect = detect_thinkpad_privacy_screen,
+   },
+#endif
+};
+
+void __init drm_privacy_screen_lookup_init(void)
+{
+   int i;
+
+   for (i = 0; i < ARRAY_SIZE(arch_init_data); i++) {
+   if (!arch_init_data[i].detect())
+   continue;
+
+   pr_info("Found '%s' privacy-screen provider\n",
+   arch_init_data[i].lookup.provider);
+
+   /* Make a copy because arch_init_data is __initconst */
+   arch_lookup = arch_init_data[i].lookup;
+   drm_privacy_screen_lookup_add(&arch_lookup);
+   break;
+   }
+}
+
+void drm_privacy_screen_lookup_exit(void)
+{
+   if (arch_lookup.provider)
+   drm_privacy_screen_lookup_remove(&arch_lookup);
+}
+#endif /* ifdef CONFIG_X86 */
diff --git a/include/drm/drm_privacy_screen_machine.h 
b/include/drm/drm_privacy_screen_machine.h
index aaa0d38cce92..02e5371904d3 100644
--- a/include/drm/drm_privacy_screen_machine.h
+++ b/include/drm/drm_privacy_screen_machine.h
@@ -31,11 +31,16 @@ struct drm_privacy_screen_lookup {
 void drm_privacy_screen_lookup_add(struct drm_privacy_screen_lookup *lookup);
 void drm_privacy_screen_lookup_remove(struct drm_privacy_screen_lookup 
*lookup);
 
+#if IS_ENABLED(CONFIG_DRM_PRIVACY_SCREEN) && IS_ENABLED(CONFIG_X86)
+void drm_privacy_screen_lookup_init(void);
+void drm_privacy_screen_lookup_exit(void);
+#else
 static inline void drm_privacy_screen_lookup_init(void)
 {
 }
 static inline void drm_privacy_screen_lookup_exit(void)
 {
 }
+#endif
 
 #endif
-- 
2.31.1

[PATCH 03/10] drm/privacy-screen: Add X86 specific arch init code

2021-10-02 Thread Hans de Goede 
Add X86 specific arch init code, which fills the privacy-screen lookup
table by checking for various vendor specific ACPI interfaces for
controlling the privacy-screen.

This initial version only checks for the Lenovo Thinkpad specific ACPI
methods for privacy-screen control.

Reviewed-by: Emil Velikov 
Reviewed-by: Lyude Paul 
Signed-off-by: Hans de Goede 
---
 drivers/gpu/drm/Makefile |  2 +-
 drivers/gpu/drm/drm_privacy_screen_x86.c | 86 
 include/drm/drm_privacy_screen_machine.h |  5 ++
 3 files changed, 92 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/drm_privacy_screen_x86.c

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 788fc37096f6..12997ca5670d 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -32,7 +32,7 @@ drm-$(CONFIG_OF) += drm_of.o
 drm-$(CONFIG_PCI) += drm_pci.o
 drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o
 drm-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
-drm-$(CONFIG_DRM_PRIVACY_SCREEN) += drm_privacy_screen.o
+drm-$(CONFIG_DRM_PRIVACY_SCREEN) += drm_privacy_screen.o 
drm_privacy_screen_x86.o
 
 obj-$(CONFIG_DRM_DP_AUX_BUS) += drm_dp_aux_bus.o
 
diff --git a/drivers/gpu/drm/drm_privacy_screen_x86.c 
b/drivers/gpu/drm/drm_privacy_screen_x86.c
new file mode 100644
index ..a2cafb294ca6
--- /dev/null
+++ b/drivers/gpu/drm/drm_privacy_screen_x86.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright (C) 2020 Red Hat, Inc.
+ *
+ * Authors:
+ * Hans de Goede 
+ */
+
+#include 
+#include 
+
+#ifdef CONFIG_X86
+static struct drm_privacy_screen_lookup arch_lookup;
+
+struct arch_init_data {
+   struct drm_privacy_screen_lookup lookup;
+   bool (*detect)(void);
+};
+
+#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
+static acpi_status __init acpi_set_handle(acpi_handle handle, u32 level,
+ void *context, void **return_value)
+{
+   *(acpi_handle *)return_value = handle;
+   return AE_CTRL_TERMINATE;
+}
+
+static bool __init detect_thinkpad_privacy_screen(void)
+{
+   union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
+   struct acpi_object_list args = { .count = 1, .pointer = &obj, };
+   acpi_handle ec_handle = NULL;
+   unsigned long long output;
+   acpi_status status;
+
+   /* Get embedded-controller handle */
+   status = acpi_get_devices("PNP0C09", acpi_set_handle, NULL, &ec_handle);
+   if (ACPI_FAILURE(status) || !ec_handle)
+   return false;
+
+   /* And call the privacy-screen get-status method */
+   status = acpi_evaluate_integer(ec_handle, "HKEY.GSSS", &args, &output);
+   if (ACPI_FAILURE(status))
+   return false;
+
+   return (output & 0x1) ? true : false;
+}
+#endif
+
+static const struct arch_init_data arch_init_data[] __initconst = {
+#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
+   {
+   .lookup = {
+   .dev_id = NULL,
+   .con_id = NULL,
+   .provider = "privacy_screen-thinkpad_acpi",
+   },
+   .detect = detect_thinkpad_privacy_screen,
+   },
+#endif
+};
+
+void __init drm_privacy_screen_lookup_init(void)
+{
+   int i;
+
+   for (i = 0; i < ARRAY_SIZE(arch_init_data); i++) {
+   if (!arch_init_data[i].detect())
+   continue;
+
+   pr_info("Found '%s' privacy-screen provider\n",
+   arch_init_data[i].lookup.provider);
+
+   /* Make a copy because arch_init_data is __initconst */
+   arch_lookup = arch_init_data[i].lookup;
+   drm_privacy_screen_lookup_add(&arch_lookup);
+   break;
+   }
+}
+
+void drm_privacy_screen_lookup_exit(void)
+{
+   if (arch_lookup.provider)
+   drm_privacy_screen_lookup_remove(&arch_lookup);
+}
+#endif /* ifdef CONFIG_X86 */
diff --git a/include/drm/drm_privacy_screen_machine.h 
b/include/drm/drm_privacy_screen_machine.h
index aaa0d38cce92..02e5371904d3 100644
--- a/include/drm/drm_privacy_screen_machine.h
+++ b/include/drm/drm_privacy_screen_machine.h
@@ -31,11 +31,16 @@ struct drm_privacy_screen_lookup {
 void drm_privacy_screen_lookup_add(struct drm_privacy_screen_lookup *lookup);
 void drm_privacy_screen_lookup_remove(struct drm_privacy_screen_lookup 
*lookup);
 
+#if IS_ENABLED(CONFIG_DRM_PRIVACY_SCREEN) && IS_ENABLED(CONFIG_X86)
+void drm_privacy_screen_lookup_init(void);
+void drm_privacy_screen_lookup_exit(void);
+#else
 static inline void drm_privacy_screen_lookup_init(void)
 {
 }
 static inline void drm_privacy_screen_lookup_exit(void)
 {
 }
+#endif
 
 #endif
-- 
2.31.1