[PATCH v3 RESEND] media: vimc: fla: Add virtual flash subdevice

From: Lucas A. M. MagalhÃes
Date: Tue Dec 03 2019 - 18:02:00 EST


From: Lucas A. M. Magalhaes <lucmaga@xxxxxxxxx>

Add a virtual subdevice to simulate the flash control API.
Those are the supported controls:
v4l2-ctl -d /dev/v4l-subdev6 -L
Flash Controls

led_mode 0x009c0901 (menu) : min=0 max=2 default=1 value=1
0: Off
1: Flash
2: Torch
strobe_source 0x009c0902 (menu) : min=0 max=1 default=0 value=0
0: Software
1: External
strobe 0x009c0903 (button) : flags=write-only, execute-on-write
stop_strobe 0x009c0904 (button) : flags=write-only, execute-on-write
strobe_status 0x009c0905 (bool) : default=0 value=0 flags=read-only
strobe_timeout 0x009c0906 (int) : min=50 max=400 step=50 default=50 value=400
intensity_flash_mode 0x009c0907 (int) : min=23040 max=1499600 step=11718 default=23040 value=23040
intensity_torch_mode 0x009c0908 (int) : min=2530 max=187100 step=1460 default=2530 value=2530
intensity_indicator 0x009c0909 (int) : min=0 max=255 step=1 default=0 value=0
faults 0x009c090a (bitmask): max=0x00000002 default=0x00000000 value=0x00000000

Co-authored-by: Eduardo Barretto <edusbarretto@xxxxxxxxx>
Signed-off-by: Eduardo Barretto <edusbarretto@xxxxxxxxx>
Signed-off-by: Lucas A. M. MagalhÃes <lucmaga@xxxxxxxxx>

---
Hi,

I've copied some values from another driver (lm3646) to make it more
realistic, as suggested by Hans. All values except for
V4L2_CID_FLASH_INDICATOR_INTENSITY, which I couldn't find any
implementation.

The v4l-compliance is failing. From the documentation
V4L2_CID_FLASH_STROBE should just work if the
V4L2_CID_FLASH_STROBE_SOURCE is "Software" and the
V4L2_CID_FLASH_LED_MODE is "Flash", otherwise it should fail. With the
standard values configured for the V4L2_CID_FLASH_STROBE will not fail.
But during the tests v4l-compliance sets V4L2_CID_FLASH_LED_MODE to
"Torch" and V4L2_CID_FLASH_STROBE_SOURCE to "External" which makes
V4L2_CID_FLASH_STROBE to fail. How do I proceed? Should the
v4l-compliance be changed?

Changes in v3:
- Fix style errors
- Use more realistic numbers for the controllers
- Change from kthread to workqueue
- Change commit message for the new controllers values

Changes in v2:
- Fix v4l2-complience errors
- Add V4L2_CID_FLASH_STROBE_STATUS behavior
- Add V4L2_CID_FLASH_STROBE restrictions
- Remove vimc_fla_g_volatile_ctrl
- Remove unnecessarie V4L2_CID_FLASH_CLASS
- Change varables names

drivers/media/platform/vimc/Makefile | 2 +-
drivers/media/platform/vimc/vimc-common.c | 2 +
drivers/media/platform/vimc/vimc-common.h | 4 +
drivers/media/platform/vimc/vimc-core.c | 5 +
drivers/media/platform/vimc/vimc-flash.c | 248 ++++++++++++++++++++++
5 files changed, 260 insertions(+), 1 deletion(-)
create mode 100644 drivers/media/platform/vimc/vimc-flash.c

diff --git a/drivers/media/platform/vimc/Makefile b/drivers/media/platform/vimc/Makefile
index a53b2b532e9f..e759bbb04b14 100644
--- a/drivers/media/platform/vimc/Makefile
+++ b/drivers/media/platform/vimc/Makefile
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
vimc-y := vimc-core.o vimc-common.o vimc-streamer.o vimc-capture.o \
- vimc-debayer.o vimc-scaler.o vimc-sensor.o
+ vimc-debayer.o vimc-scaler.o vimc-sensor.o vimc-flash.o

obj-$(CONFIG_VIDEO_VIMC) += vimc.o

diff --git a/drivers/media/platform/vimc/vimc-common.c b/drivers/media/platform/vimc/vimc-common.c
index a3120f4f7a90..cb786de75573 100644
--- a/drivers/media/platform/vimc/vimc-common.c
+++ b/drivers/media/platform/vimc/vimc-common.c
@@ -203,6 +203,8 @@ struct media_pad *vimc_pads_init(u16 num_pads, const unsigned long *pads_flag)
struct media_pad *pads;
unsigned int i;

+ if (!num_pads)
+ return NULL;
/* Allocate memory for the pads */
pads = kcalloc(num_pads, sizeof(*pads), GFP_KERNEL);
if (!pads)
diff --git a/drivers/media/platform/vimc/vimc-common.h b/drivers/media/platform/vimc/vimc-common.h
index 698db7c07645..19815f0f4d40 100644
--- a/drivers/media/platform/vimc/vimc-common.h
+++ b/drivers/media/platform/vimc/vimc-common.h
@@ -169,6 +169,10 @@ struct vimc_ent_device *vimc_sen_add(struct vimc_device *vimc,
const char *vcfg_name);
void vimc_sen_rm(struct vimc_device *vimc, struct vimc_ent_device *ved);

+struct vimc_ent_device *vimc_fla_add(struct vimc_device *vimc,
+ const char *vcfg_name);
+void vimc_fla_rm(struct vimc_device *vimc, struct vimc_ent_device *ved);
+
/**
* vimc_pads_init - initialize pads
*
diff --git a/drivers/media/platform/vimc/vimc-core.c b/drivers/media/platform/vimc/vimc-core.c
index 6e3e5c91ae39..5f6c750d3d8d 100644
--- a/drivers/media/platform/vimc/vimc-core.c
+++ b/drivers/media/platform/vimc/vimc-core.c
@@ -91,6 +91,11 @@ static struct vimc_ent_config ent_config[] = {
.add = vimc_cap_add,
.rm = vimc_cap_rm,
},
+ {
+ .name = "Flash Controller",
+ .add = vimc_fla_add,
+ .rm = vimc_fla_rm,
+ }
};

static const struct vimc_ent_link ent_links[] = {
diff --git a/drivers/media/platform/vimc/vimc-flash.c b/drivers/media/platform/vimc/vimc-flash.c
new file mode 100644
index 000000000000..3918beecec57
--- /dev/null
+++ b/drivers/media/platform/vimc/vimc-flash.c
@@ -0,0 +1,248 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * vimc-flash.c Virtual Media Controller Driver
+ *
+ * Copyright (C) 2019
+ * Contributors: Lucas A. M. MagalhÃes <lamm@xxxxxxxxxxx>
+ * Eduardo Barretto <edusbarretto@xxxxxxxxx>
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/workqueue.h>
+#include <linux/sched.h>
+#include <linux/vmalloc.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-subdev.h>
+
+#include "vimc-common.h"
+
+/*
+ * Flash timeout in ms
+ */
+#define VIMC_FLASH_TIMEOUT_MS_MIN 50
+#define VIMC_FLASH_TIMEOUT_MS_MAX 400
+#define VIMC_FLASH_TIMEOUT_MS_STEP 50
+
+/*
+ * Torch intencity in uA
+ */
+#define VIMC_FLASH_TORCH_UA_MIN 2530
+#define VIMC_FLASH_TORCH_UA_MAX 187100
+#define VIMC_FLASH_TORCH_UA_STEP 1460
+
+/*
+ * Flash intencity in uA
+ */
+#define VIMC_FLASH_FLASH_UA_MIN 23040
+#define VIMC_FLASH_FLASH_UA_MAX 1499600
+#define VIMC_FLASH_FLASH_UA_STEP 11718
+
+struct vimc_fla_device {
+ struct vimc_ent_device ved;
+ struct v4l2_subdev sd;
+ struct v4l2_ctrl_handler hdl;
+ int strobe_source;
+ bool is_strobe;
+ int led_mode;
+ int indicator_intensity;
+ int torch_intensity;
+ int flash_intensity;
+ u64 timeout;
+ u64 last_strobe;
+ struct workqueue_struct *wq;
+ struct work_struct work;
+ struct v4l2_ctrl *strobe_status_ctl;
+};
+
+static void vimc_fla_strobe_work(struct work_struct *work)
+{
+ struct vimc_fla_device *vfla =
+ container_of(work, struct vimc_fla_device, work);
+ v4l2_ctrl_s_ctrl(vfla->strobe_status_ctl, true);
+ vfla->last_strobe = ktime_get_ns();
+ while (vfla->is_strobe &&
+ vfla->last_strobe + vfla->timeout > ktime_get_ns()) {
+ msleep_interruptible(VIMC_FLASH_TIMEOUT_MS_STEP);
+ }
+ v4l2_ctrl_s_ctrl(vfla->strobe_status_ctl, false);
+}
+
+static int vimc_fla_s_ctrl(struct v4l2_ctrl *c)
+{
+ struct vimc_fla_device *vfla =
+ container_of(c->handler, struct vimc_fla_device, hdl);
+
+ switch (c->id) {
+ case V4L2_CID_FLASH_LED_MODE:
+ vfla->led_mode = c->val;
+ return 0;
+ case V4L2_CID_FLASH_STROBE_SOURCE:
+ vfla->strobe_source = c->val;
+ return 0;
+ case V4L2_CID_FLASH_STROBE:
+ if (vfla->led_mode != V4L2_FLASH_LED_MODE_FLASH ||
+ vfla->strobe_source != V4L2_FLASH_STROBE_SOURCE_SOFTWARE){
+ return -EINVAL;
+ }
+ queue_work(vfla->wq, &vfla->work);
+ return 0;
+ case V4L2_CID_FLASH_STROBE_STATUS:
+ vfla->is_strobe = c->val;
+ return 0;
+ case V4L2_CID_FLASH_STROBE_STOP:
+ vfla->is_strobe = false;
+ return 0;
+ case V4L2_CID_FLASH_TIMEOUT:
+ vfla->timeout = c->val * 1000000; /* MS to NS */
+ return 0;
+ case V4L2_CID_FLASH_INTENSITY:
+ vfla->flash_intensity = c->val;
+ return 0;
+ case V4L2_CID_FLASH_TORCH_INTENSITY:
+ vfla->torch_intensity = c->val;
+ return 0;
+ case V4L2_CID_FLASH_INDICATOR_INTENSITY:
+ vfla->indicator_intensity = c->val;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static const struct v4l2_ctrl_ops vimc_fla_ctrl_ops = {
+ .s_ctrl = vimc_fla_s_ctrl,
+};
+
+static const struct v4l2_subdev_core_ops vimc_fla_core_ops = {
+ .subscribe_event = v4l2_ctrl_subdev_subscribe_event,
+ .unsubscribe_event = v4l2_event_subdev_unsubscribe,
+};
+
+static const struct v4l2_subdev_ops vimc_fla_ops = {
+ .core = &vimc_fla_core_ops,
+};
+
+static void vimc_fla_release(struct v4l2_subdev *sd)
+{
+ struct vimc_fla_device *vfla =
+ container_of(sd, struct vimc_fla_device, sd);
+
+ v4l2_ctrl_handler_free(&vfla->hdl);
+ kfree(vfla);
+}
+
+static const struct v4l2_subdev_internal_ops vimc_fla_int_ops = {
+ .release = vimc_fla_release,
+};
+
+/* initialize device */
+struct vimc_ent_device *vimc_fla_add(struct vimc_device *vimc,
+ const char *vcfg_name)
+{
+ struct v4l2_device *v4l2_dev = &vimc->v4l2_dev;
+ struct vimc_fla_device *vfla;
+ int ret;
+
+ /* Allocate the vfla struct */
+ vfla = kzalloc(sizeof(*vfla), GFP_KERNEL);
+ if (!vfla)
+ return NULL;
+
+ v4l2_ctrl_handler_init(&vfla->hdl, 4);
+ v4l2_ctrl_new_std_menu(&vfla->hdl, &vimc_fla_ctrl_ops,
+ V4L2_CID_FLASH_LED_MODE,
+ V4L2_FLASH_LED_MODE_TORCH, ~0x7,
+ V4L2_FLASH_LED_MODE_FLASH);
+ v4l2_ctrl_new_std_menu(&vfla->hdl, &vimc_fla_ctrl_ops,
+ V4L2_CID_FLASH_STROBE_SOURCE, 0x1, ~0x3,
+ V4L2_FLASH_STROBE_SOURCE_SOFTWARE);
+ v4l2_ctrl_new_std(&vfla->hdl, &vimc_fla_ctrl_ops,
+ V4L2_CID_FLASH_STROBE, 0, 0, 0, 0);
+ v4l2_ctrl_new_std(&vfla->hdl, &vimc_fla_ctrl_ops,
+ V4L2_CID_FLASH_STROBE_STOP, 0, 0, 0, 0);
+ v4l2_ctrl_new_std(&vfla->hdl, &vimc_fla_ctrl_ops,
+ V4L2_CID_FLASH_TIMEOUT, VIMC_FLASH_TIMEOUT_MS_MIN,
+ VIMC_FLASH_TIMEOUT_MS_MAX,
+ VIMC_FLASH_TIMEOUT_MS_STEP,
+ VIMC_FLASH_TIMEOUT_MS_MIN);
+ v4l2_ctrl_new_std(&vfla->hdl, &vimc_fla_ctrl_ops,
+ V4L2_CID_FLASH_TORCH_INTENSITY,
+ VIMC_FLASH_TORCH_UA_MIN,
+ VIMC_FLASH_TORCH_UA_MAX,
+ VIMC_FLASH_TORCH_UA_STEP,
+ VIMC_FLASH_TORCH_UA_MIN);
+ v4l2_ctrl_new_std(&vfla->hdl, &vimc_fla_ctrl_ops,
+ V4L2_CID_FLASH_INTENSITY,
+ VIMC_FLASH_FLASH_UA_MIN,
+ VIMC_FLASH_FLASH_UA_MAX,
+ VIMC_FLASH_FLASH_UA_STEP,
+ VIMC_FLASH_FLASH_UA_MIN);
+ v4l2_ctrl_new_std(&vfla->hdl, &vimc_fla_ctrl_ops,
+ V4L2_CID_FLASH_INDICATOR_INTENSITY,
+ 0,
+ 255,
+ 1,
+ 0);
+ v4l2_ctrl_new_std(&vfla->hdl, &vimc_fla_ctrl_ops,
+ V4L2_CID_FLASH_STROBE_STATUS, 0, 1, 1, 0);
+ v4l2_ctrl_new_std(&vfla->hdl, &vimc_fla_ctrl_ops,
+ V4L2_CID_FLASH_FAULT, 0,
+ V4L2_FLASH_FAULT_TIMEOUT, 0, 0);
+ vfla->sd.ctrl_handler = &vfla->hdl;
+ if (vfla->hdl.error) {
+ ret = vfla->hdl.error;
+ goto err_free_vfla;
+ }
+ vfla->strobe_status_ctl = v4l2_ctrl_find(&vfla->hdl,
+ V4L2_CID_FLASH_STROBE_STATUS);
+
+ /* Initialize ved and sd */
+ ret = vimc_ent_sd_register(&vfla->ved, &vfla->sd, v4l2_dev,
+ vcfg_name,
+ MEDIA_ENT_F_FLASH, 0, NULL,
+ &vimc_fla_int_ops, &vimc_fla_ops);
+ if (ret)
+ goto err_free_hdl;
+
+ /* Create processing workqueue */
+ vfla->wq = alloc_workqueue("%s", 0, 0, "vimc-flash thread");
+ if (!vfla->wq)
+ goto err_unregister;
+
+ INIT_WORK(&vfla->work, vimc_fla_strobe_work);
+ /* Initialize standard values */
+ vfla->indicator_intensity = 0;
+ vfla->torch_intensity = 0;
+ vfla->flash_intensity = 0;
+ vfla->is_strobe = false;
+ vfla->timeout = 0;
+ vfla->last_strobe = 0;
+ vfla->strobe_source = V4L2_FLASH_STROBE_SOURCE_SOFTWARE;
+ vfla->led_mode = V4L2_FLASH_LED_MODE_FLASH;
+
+ return &vfla->ved;
+
+err_unregister:
+ vimc_ent_sd_unregister(&vfla->ved, &vfla->sd);
+err_free_hdl:
+ v4l2_ctrl_handler_free(&vfla->hdl);
+err_free_vfla:
+ kfree(vfla);
+
+ return NULL;
+}
+
+void vimc_fla_rm(struct vimc_device *vimc, struct vimc_ent_device *ved)
+{
+ struct vimc_fla_device *vfla;
+
+ if (!ved)
+ return;
+
+ vfla = container_of(ved, struct vimc_fla_device, ved);
+ destroy_workqueue(vfla->wq);
+ vimc_ent_sd_unregister(ved, &vfla->sd);
+}
--
2.23.0