greybus: lights: add lights implementation

This patch adds lights implementation for Greybus Lights class, it
allows multiplexing of lights devices using the same connection. Also
adds two sysfs entries to led class (color, fade) which are commonly
used in several existing LED devices.

It support 2 major class of devices (normal LED and flash type), for
the first it registers to led_classdev, for the latest it registers in
the led_classdev_flash and v4l2_flash, depending on the support of the
kernel version.

Each Module can have N light devices attach and each light can have
multiple channel associated:
glights
   |->light0
   |     |->channel0
   |     |->channel1
   |     | ....
   |     |->channeln
   |->...
   |->lightn
         |->channel0
         |->channel1
         | ....
         |->channeln

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/Makefile

@@ -30,6 +30,7 @@ gb-phy-y :=	gpbridge.o	\
 gb-vibrator-y := vibrator.o
 gb-battery-y := battery.o
 gb-loopback-y := loopback.o
+gb-light-y := light.o
 gb-raw-y := raw.o
 gb-es1-y := es1.o
 gb-es2-y := es2.o
@@ -39,6 +40,7 @@ obj-m += gb-phy.o
 obj-m += gb-vibrator.o
 obj-m += gb-battery.o
 obj-m += gb-loopback.o
+obj-m += gb-light.o
 obj-m += gb-raw.o
 obj-m += gb-es1.o
 obj-m += gb-es2.o

drivers/staging/greybus/greybus_protocols.h

@@ -1067,5 +1067,181 @@ struct gb_sdio_event_request {
 #define GB_SDIO_WP		0x04
 };
 
+/* Lights */
+
+#define GB_LIGHTS_VERSION_MAJOR 0x00
+#define GB_LIGHTS_VERSION_MINOR 0x01
+
+/* Greybus Lights request types */
+#define GB_LIGHTS_TYPE_INVALID			0x00
+#define GB_LIGHTS_TYPE_PROTOCOL_VERSION		0x01
+#define GB_LIGHTS_TYPE_GET_LIGHTS		0x02
+#define GB_LIGHTS_TYPE_GET_LIGHT_CONFIG		0x03
+#define GB_LIGHTS_TYPE_GET_CHANNEL_CONFIG	0x04
+#define GB_LIGHTS_TYPE_GET_CHANNEL_FLASH_CONFIG	0x05
+#define GB_LIGHTS_TYPE_SET_BRIGHTNESS		0x06
+#define GB_LIGHTS_TYPE_SET_BLINK		0x07
+#define GB_LIGHTS_TYPE_SET_COLOR		0x08
+#define GB_LIGHTS_TYPE_SET_FADE			0x09
+#define GB_LIGHTS_TYPE_EVENT			0x0A
+#define GB_LIGHTS_TYPE_SET_FLASH_INTENSITY	0x0B
+#define GB_LIGHTS_TYPE_SET_FLASH_STROBE		0x0C
+#define GB_LIGHTS_TYPE_SET_FLASH_TIMEOUT	0x0D
+#define GB_LIGHTS_TYPE_GET_FLASH_FAULT		0x0E
+
+/* Greybus Light modes */
+
+/*
+ * if you add any specific mode below, update also the
+ * GB_CHANNEL_MODE_DEFINED_RANGE value accordingly
+ */
+#define GB_CHANNEL_MODE_NONE		0x00000000
+#define GB_CHANNEL_MODE_BATTERY		0x00000001
+#define GB_CHANNEL_MODE_POWER		0x00000002
+#define GB_CHANNEL_MODE_WIRELESS	0x00000004
+#define GB_CHANNEL_MODE_BLUETOOTH	0x00000008
+#define GB_CHANNEL_MODE_KEYBOARD	0x00000010
+#define GB_CHANNEL_MODE_BUTTONS		0x00000020
+#define GB_CHANNEL_MODE_NOTIFICATION	0x00000040
+#define GB_CHANNEL_MODE_ATTENTION	0x00000080
+#define GB_CHANNEL_MODE_FLASH		0x00000100
+#define GB_CHANNEL_MODE_TORCH		0x00000200
+#define GB_CHANNEL_MODE_INDICATOR	0x00000400
+
+/* Lights Mode valid bit values */
+#define GB_CHANNEL_MODE_DEFINED_RANGE	0x000004FF
+#define GB_CHANNEL_MODE_VENDOR_RANGE	0x00F00000
+
+/* Greybus Light Channels Flags */
+#define GB_LIGHT_CHANNEL_MULTICOLOR	0x00000001
+#define GB_LIGHT_CHANNEL_FADER		0x00000002
+#define GB_LIGHT_CHANNEL_BLINK		0x00000004
+
+/* get count of lights in module */
+struct gb_lights_get_lights_response {
+	__u8	lights_count;
+};
+
+/* light config request payload */
+struct gb_lights_get_light_config_request {
+	__u8	id;
+};
+
+/* light config response payload */
+struct gb_lights_get_light_config_response {
+	__u8	channel_count;
+	__u8	name[32];
+};
+
+/* channel config request payload */
+struct gb_lights_get_channel_config_request {
+	__u8	light_id;
+	__u8	channel_id;
+};
+
+/* channel flash config request payload */
+struct gb_lights_get_channel_flash_config_request {
+	__u8	light_id;
+	__u8	channel_id;
+};
+
+/* channel config response payload */
+struct gb_lights_get_channel_config_response {
+	__u8	max_brightness;
+	__le32	flags;
+	__le32	color;
+	__u8	color_name[32];
+	__le32	mode;
+	__u8	mode_name[32];
+} __packed;
+
+/* channel flash config response payload */
+struct gb_lights_get_channel_flash_config_response {
+	__le32	intensity_min_uA;
+	__le32	intensity_max_uA;
+	__le32	intensity_step_uA;
+	__le32	timeout_min_us;
+	__le32	timeout_max_us;
+	__le32	timeout_step_us;
+};
+
+/* blink request payload: response have no payload */
+struct gb_lights_blink_request {
+	__u8	light_id;
+	__u8	channel_id;
+	__le16	time_on_ms;
+	__le16	time_off_ms;
+};
+
+/* set brightness request payload: response have no payload */
+struct gb_lights_set_brightness_request {
+	__u8	light_id;
+	__u8	channel_id;
+	__u8	brightness;
+};
+
+/* set color request payload: response have no payload */
+struct gb_lights_set_color_request {
+	__u8	light_id;
+	__u8	channel_id;
+	__le32	color;
+} __packed;
+
+/* set fade request payload: response have no payload */
+struct gb_lights_set_fade_request {
+	__u8	light_id;
+	__u8	channel_id;
+	__u8	fade_in;
+	__u8	fade_out;
+};
+
+/* event request: generated by module */
+struct gb_lights_event_request {
+	__u8	light_id;
+	__u8	event;
+#define GB_LIGHTS_LIGHT_CONFIG		0x01
+};
+
+/* set flash intensity request payload: response have no payload */
+struct gb_lights_set_flash_intensity_request {
+	__u8	light_id;
+	__u8	channel_id;
+	__le32	intensity_uA;
+} __packed;
+
+/* set flash strobe state request payload: response have no payload */
+struct gb_lights_set_flash_strobe_request {
+	__u8	light_id;
+	__u8	channel_id;
+	__u8	state;
+};
+
+/* set flash timeout request payload: response have no payload */
+struct gb_lights_set_flash_timeout_request {
+	__u8	light_id;
+	__u8	channel_id;
+	__le32	timeout_us;
+} __packed;
+
+/* get flash fault request payload */
+struct gb_lights_get_flash_fault_request {
+	__u8	light_id;
+	__u8	channel_id;
+};
+
+/* get flash fault response payload */
+struct gb_lights_get_flash_fault_response {
+	__le32	fault;
+#define GB_LIGHTS_FLASH_FAULT_OVER_VOLTAGE		0x00000000
+#define GB_LIGHTS_FLASH_FAULT_TIMEOUT			0x00000001
+#define GB_LIGHTS_FLASH_FAULT_OVER_TEMPERATURE		0x00000002
+#define GB_LIGHTS_FLASH_FAULT_SHORT_CIRCUIT		0x00000004
+#define GB_LIGHTS_FLASH_FAULT_OVER_CURRENT		0x00000008
+#define GB_LIGHTS_FLASH_FAULT_INDICATOR			0x00000010
+#define GB_LIGHTS_FLASH_FAULT_UNDER_VOLTAGE		0x00000020
+#define GB_LIGHTS_FLASH_FAULT_INPUT_VOLTAGE		0x00000040
+#define GB_LIGHTS_FLASH_FAULT_LED_OVER_TEMPERATURE	0x00000080
+};
+
 #endif /* __GREYBUS_PROTOCOLS_H */
 

drivers/staging/greybus/kernel_ver.h

@@ -248,4 +248,45 @@ static inline size_t sg_pcopy_from_buffer(struct scatterlist *sgl,
 	list_entry((ptr)->prev, type, member)
 #endif
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 17, 0)
+/*
+ * Before this version the led classdev did not support groups
+ */
+#define LED_HAVE_GROUPS
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 19, 0)
+/*
+ * At this time the internal API for the set brightness was changed to the async
+ * version, and one sync API was added to handle cases that need immediate
+ * effect. Also, the led class flash and lock for sysfs access was introduced.
+ */
+#define LED_HAVE_SET_SYNC
+#define LED_HAVE_FLASH
+#define LED_HAVE_LOCK
+#include <linux/led-class-flash.h>
+#endif
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 18, 0)
+/*
+ * From this version upper it was introduced the possibility to disable led
+ * sysfs entries to handle control of the led device to v4l2, which was
+ * implemented later. So, before that this should return false.
+ */
+#include <linux/leds.h>
+static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
+{
+	return false;
+}
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 2, 0)
+/*
+ * New helper functions for registering/unregistering flash led devices as v4l2
+ * subdevices were added.
+ */
+#define V4L2_HAVE_FLASH
+#include <media/v4l2-flash-led-class.h>
+#endif
+
 #endif	/* __GREYBUS_KERNEL_VER_H */