[PATCH v3 2/2] Add GS1662 driver, a video serializer

[Charles-Antoine Couret <charles-antoine.couret@nexvision.fr>]

You can read datasheet here:
http://www.c-dis.net/media/871/GS1662_Datasheet.pdf

It's a component which supports HD and SD CEA or SDI formats
to SDI output. It's configured through SPI bus.

GS1662 driver is implemented as v4l2 subdev.

Signed-off-by: Charles-Antoine Couret <charles-antoine.couret@nexvision.fr>
---
 drivers/media/Kconfig      |   1 +
 drivers/media/Makefile     |   2 +-
 drivers/media/spi/Kconfig  |   9 +
 drivers/media/spi/Makefile |   1 +
 drivers/media/spi/gs1662.c | 472 +++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 484 insertions(+), 1 deletion(-)
 create mode 100644 drivers/media/spi/Kconfig
 create mode 100644 drivers/media/spi/Makefile
 create mode 100644 drivers/media/spi/gs1662.c

diff --git a/drivers/media/Kconfig b/drivers/media/Kconfig
index a8518fb..d2fa6e7 100644
--- a/drivers/media/Kconfig
+++ b/drivers/media/Kconfig
@@ -215,5 +215,6 @@ config MEDIA_ATTACH
 source "drivers/media/i2c/Kconfig"
 source "drivers/media/tuners/Kconfig"
 source "drivers/media/dvb-frontends/Kconfig"
+source "drivers/media/spi/Kconfig"
 
 endif # MEDIA_SUPPORT
diff --git a/drivers/media/Makefile b/drivers/media/Makefile
index e608bbc..75bc82e 100644
--- a/drivers/media/Makefile
+++ b/drivers/media/Makefile
@@ -28,6 +28,6 @@ obj-y += rc/
 # Finally, merge the drivers that require the core
 #
 
-obj-y += common/ platform/ pci/ usb/ mmc/ firewire/
+obj-y += common/ platform/ pci/ usb/ mmc/ firewire/ spi/
 obj-$(CONFIG_VIDEO_DEV) += radio/
 
diff --git a/drivers/media/spi/Kconfig b/drivers/media/spi/Kconfig
new file mode 100644
index 0000000..fa47c90
--- /dev/null
+++ b/drivers/media/spi/Kconfig
@@ -0,0 +1,9 @@
+if VIDEO_V4L2
+
+config VIDEO_GS1662
+	tristate "Gennum Serializers video"
+	depends on SPI && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API
+	---help---
+	  Enable the GS1662 driver which serializes video streams.
+
+endif
diff --git a/drivers/media/spi/Makefile b/drivers/media/spi/Makefile
new file mode 100644
index 0000000..ea64013
--- /dev/null
+++ b/drivers/media/spi/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_VIDEO_GS1662) += gs1662.o
diff --git a/drivers/media/spi/gs1662.c b/drivers/media/spi/gs1662.c
new file mode 100644
index 0000000..f743423
--- /dev/null
+++ b/drivers/media/spi/gs1662.c
@@ -0,0 +1,472 @@
+/*
+ * GS1662 device registration.
+ *
+ * Copyright (C) 2015-2016 Nexvision
+ * Author: Charles-Antoine Couret <charles-antoine.couret@nexvision.fr>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/spi/spi.h>
+#include <linux/platform_device.h>
+#include <linux/ctype.h>
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/module.h>
+
+#include <linux/videodev2.h>
+#include <media/v4l2-common.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-subdev.h>
+#include <media/v4l2-dv-timings.h>
+#include <linux/v4l2-dv-timings.h>
+
+#define REG_STATUS			0x04
+#define REG_FORCE_FMT			0x06
+#define REG_LINES_PER_FRAME		0x12
+#define REG_WORDS_PER_LINE		0x13
+#define REG_WORDS_PER_ACT_LINE		0x14
+#define REG_ACT_LINES_PER_FRAME	0x15
+
+#define MASK_H_LOCK			0x001
+#define MASK_V_LOCK			0x002
+#define MASK_STD_LOCK			0x004
+#define MASK_FORCE_STD			0x020
+#define MASK_STD_STATUS		0x3E0
+
+#define GS_WIDTH_MIN			720
+#define GS_WIDTH_MAX			2048
+#define GS_HEIGHT_MIN			487
+#define GS_HEIGHT_MAX			1080
+#define GS_PIXELCLOCK_MIN		10519200
+#define GS_PIXELCLOCK_MAX		74250000
+
+struct gs {
+	struct spi_device *pdev;
+	struct v4l2_subdev sd;
+	struct v4l2_dv_timings current_timings;
+	int enabled;
+};
+
+struct gs_reg_fmt {
+	u16 reg_value;
+	struct v4l2_dv_timings format;
+};
+
+struct gs_reg_fmt_custom {
+	u16 reg_value;
+	__u32 width;
+	__u32 height;
+	__u64 pixelclock;
+	__u32 interlaced;
+};
+
+static const struct spi_device_id gs_id[] = {
+	{ "gs1662", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, gs_id);
+
+static const struct v4l2_dv_timings fmt_cap[] = {
+	V4L2_DV_BT_SDI_720X487I60,
+	V4L2_DV_BT_CEA_720X576P50,
+	V4L2_DV_BT_CEA_1280X720P24,
+	V4L2_DV_BT_CEA_1280X720P25,
+	V4L2_DV_BT_CEA_1280X720P30,
+	V4L2_DV_BT_CEA_1280X720P50,
+	V4L2_DV_BT_CEA_1280X720P60,
+	V4L2_DV_BT_CEA_1920X1080P24,
+	V4L2_DV_BT_CEA_1920X1080P25,
+	V4L2_DV_BT_CEA_1920X1080P30,
+	V4L2_DV_BT_CEA_1920X1080I50,
+	V4L2_DV_BT_CEA_1920X1080I60,
+};
+
+static const struct gs_reg_fmt reg_fmt[] = {
+	{ 0x00, V4L2_DV_BT_CEA_1280X720P60 },
+	{ 0x01, V4L2_DV_BT_CEA_1280X720P60 },
+	{ 0x02, V4L2_DV_BT_CEA_1280X720P30 },
+	{ 0x03, V4L2_DV_BT_CEA_1280X720P30 },
+	{ 0x04, V4L2_DV_BT_CEA_1280X720P50 },
+	{ 0x05, V4L2_DV_BT_CEA_1280X720P50 },
+	{ 0x06, V4L2_DV_BT_CEA_1280X720P25 },
+	{ 0x07, V4L2_DV_BT_CEA_1280X720P25 },
+	{ 0x08, V4L2_DV_BT_CEA_1280X720P24 },
+	{ 0x09, V4L2_DV_BT_CEA_1280X720P24 },
+	{ 0x0A, V4L2_DV_BT_CEA_1920X1080I60 },
+	{ 0x0B, V4L2_DV_BT_CEA_1920X1080P30 },
+
+	/* Default value: keep this field before 0xC */
+	{ 0x14, V4L2_DV_BT_CEA_1920X1080I50 },
+	{ 0x0C, V4L2_DV_BT_CEA_1920X1080I50 },
+	{ 0x0D, V4L2_DV_BT_CEA_1920X1080P25 },
+	{ 0x0E, V4L2_DV_BT_CEA_1920X1080P25 },
+	{ 0x10, V4L2_DV_BT_CEA_1920X1080P24 },
+	{ 0x12, V4L2_DV_BT_CEA_1920X1080P24 },
+	{ 0x16, V4L2_DV_BT_SDI_720X487I60 },
+	{ 0x19, V4L2_DV_BT_SDI_720X487I60 },
+	{ 0x18, V4L2_DV_BT_CEA_720X576P50 },
+	{ 0x1A, V4L2_DV_BT_CEA_720X576P50 },
+
+	/* Implement following timings before enable it.
+	 * Because of we don't have access to these theoretical timings yet.
+	 * Workaround: use functions to get and set registers for these formats.
+	 */
+#if 0
+	{ 0x0F, V4L2_DV_BT_XXX_1920X1080I25 }, /* SMPTE 274M */
+	{ 0x11, V4L2_DV_BT_XXX_1920X1080I24 }, /* SMPTE 274M */
+	{ 0x13, V4L2_DV_BT_XXX_1920X1080I25 }, /* SMPTE 274M */
+	{ 0x15, V4L2_DV_BT_XXX_1920X1035I60 }, /* SMPTE 260M */
+	{ 0x17, V4L2_DV_BT_SDI_720X507I60 }, /* SMPTE 125M */
+	{ 0x1B, V4L2_DV_BT_SDI_720X507I60 }, /* SMPTE 125M */
+	{ 0x1C, V4L2_DV_BT_XXX_2048X1080P25 }, /* SMPTE 428.1M */
+#endif
+};
+
+static const struct v4l2_dv_timings_cap gs_timings_cap = {
+	.type = V4L2_DV_BT_656_1120,
+	/* keep this initialization for compatibility with GCC < 4.4.6 */
+	.reserved = { 0 },
+	V4L2_INIT_BT_TIMINGS(GS_WIDTH_MIN, GS_WIDTH_MAX, GS_HEIGHT_MIN,
+			     GS_HEIGHT_MAX, GS_PIXELCLOCK_MIN, GS_PIXELCLOCK_MAX,
+			     V4L2_DV_BT_STD_CEA861 | V4L2_DV_BT_STD_SDI,
+			     V4L2_DV_BT_CAP_PROGRESSIVE
+			     | V4L2_DV_BT_CAP_INTERLACED)
+};
+
+static int gs_read_register(struct spi_device *spi, u16 addr, u16 *value)
+{
+	int ret;
+	u16 buf_addr = (0x8000 | (0x0FFF & addr));
+	u16 buf_value = 0;
+	struct spi_message msg;
+	struct spi_transfer tx[] = {
+		{
+			.tx_buf = &buf_addr,
+			.len = 2,
+			.delay_usecs = 1,
+		}, {
+			.rx_buf = &buf_value,
+			.len = 2,
+			.delay_usecs = 1,
+		},
+	};
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&tx[0], &msg);
+	spi_message_add_tail(&tx[1], &msg);
+	ret = spi_sync(spi, &msg);
+
+	*value = buf_value;
+
+	return ret;
+}
+
+static int gs_write_register(struct spi_device *spi, u16 addr, u16 value)
+{
+	int ret;
+	u16 buf_addr = addr;
+	u16 buf_value = value;
+	struct spi_message msg;
+	struct spi_transfer tx[] = {
+		{
+			.tx_buf = &buf_addr,
+			.len = 2,
+			.delay_usecs = 1,
+		}, {
+			.tx_buf = &buf_value,
+			.len = 2,
+			.delay_usecs = 1,
+		},
+	};
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&tx[0], &msg);
+	spi_message_add_tail(&tx[1], &msg);
+	ret = spi_sync(spi, &msg);
+
+	return ret;
+}
+
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+static int gs_g_register(struct v4l2_subdev *sd,
+		  struct v4l2_dbg_register *reg)
+{
+	struct spi_device *spi = v4l2_get_subdevdata(sd);
+	u16 val;
+	int ret;
+
+	ret = gs_read_register(spi, reg->reg & 0xFFFF, &val);
+	reg->val = val;
+	reg->size = 2;
+	return ret;
+}
+
+static int gs_s_register(struct v4l2_subdev *sd,
+		  const struct v4l2_dbg_register *reg)
+{
+	struct spi_device *spi = v4l2_get_subdevdata(sd);
+
+	return gs_write_register(spi, reg->reg & 0xFFFF, reg->val & 0xFFFF);
+}
+#endif
+
+static int gs_status_format(u16 status, struct v4l2_dv_timings *timings)
+{
+	int std = (status & MASK_STD_STATUS) >> 5;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(reg_fmt); i++) {
+		if (reg_fmt[i].reg_value == std) {
+			*timings = reg_fmt[i].format;
+			return 0;
+		}
+	}
+
+	return -ERANGE;
+}
+
+static u16 get_register_timings(struct v4l2_dv_timings *timings)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(reg_fmt); i++) {
+		if (v4l2_match_dv_timings(timings, &reg_fmt[i].format, 0, false))
+			return reg_fmt[i].reg_value | MASK_FORCE_STD;
+	}
+
+	return 0x0;
+}
+
+static inline struct gs *to_gs(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct gs, sd);
+}
+
+static int gs_s_dv_timings(struct v4l2_subdev *sd,
+		    struct v4l2_dv_timings *timings)
+{
+	struct gs *gs = to_gs(sd);
+	int reg_value;
+
+	reg_value = get_register_timings(timings);
+	if (reg_value == 0x0)
+		return -EINVAL;
+
+	gs->current_timings = *timings;
+	return 0;
+}
+
+static int gs_g_dv_timings(struct v4l2_subdev *sd,
+		    struct v4l2_dv_timings *timings)
+{
+	struct gs *gs = to_gs(sd);
+
+	*timings = gs->current_timings;
+	return 0;
+}
+
+static int gs_query_dv_timings(struct v4l2_subdev *sd,
+			struct v4l2_dv_timings *timings)
+{
+	struct gs *gs = to_gs(sd);
+	struct v4l2_dv_timings fmt;
+	u16 reg_value, i;
+	int ret;
+
+	if (gs->enabled)
+		return -EBUSY;
+
+	/* Check if the component detect a line, a frame or something else
+	 * which looks like a video signal activity.*/
+	for (i = 0; i < 4; i++) {
+		gs_read_register(gs->pdev, REG_LINES_PER_FRAME + i, &reg_value);
+		if (reg_value)
+			break;
+	}
+
+	/* If no register reports a video signal */
+	if (i >= 4)
+		return -ENOLINK;
+
+	gs_read_register(gs->pdev, REG_STATUS, &reg_value);
+	if (!(reg_value & MASK_H_LOCK) || !(reg_value & MASK_V_LOCK))
+		return -ENOLCK;
+	if (!(reg_value & MASK_STD_LOCK))
+		return -ERANGE;
+
+	ret = gs_status_format(reg_value, &fmt);
+
+	if (ret < 0)
+		return ret;
+
+	*timings = fmt;
+	return 0;
+}
+
+static int gs_enum_dv_timings(struct v4l2_subdev *sd,
+		       struct v4l2_enum_dv_timings *timings)
+{
+	if (timings->index >= ARRAY_SIZE(fmt_cap))
+		return -EINVAL;
+
+	if (timings->pad != 0)
+		return -EINVAL;
+
+	timings->timings = fmt_cap[timings->index];
+	return 0;
+}
+
+static int gs_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct gs *gs = to_gs(sd);
+	int reg_value;
+
+	if (gs->enabled == enable)
+		return 0;
+
+	gs->enabled = enable;
+
+	if (enable) {
+		/* To force the specific format */
+		reg_value = get_register_timings(&gs->current_timings);
+		return gs_write_register(gs->pdev, REG_FORCE_FMT, reg_value);
+	} else {
+		/* To renable auto-detection mode */
+		return gs_write_register(gs->pdev, REG_FORCE_FMT, 0x0);
+	}
+}
+
+static int gs_g_input_status(struct v4l2_subdev *sd, u32 *status)
+{
+	struct gs *gs = to_gs(sd);
+	u16 reg_value, i;
+	int ret;
+
+	/* Check if the component detect a line, a frame or something else
+	 * which looks like a video signal activity.*/
+	for (i = 0; i < 4; i++) {
+		ret = gs_read_register(gs->pdev,
+				       REG_LINES_PER_FRAME + i, &reg_value);
+		if (reg_value)
+			break;
+		if (ret) {
+			*status = V4L2_IN_ST_NO_POWER;
+			return ret;
+		}
+	}
+
+	/* If no register reports a video signal */
+	if (i >= 4)
+		*status |= V4L2_IN_ST_NO_SIGNAL;
+
+	ret = gs_read_register(gs->pdev, REG_STATUS, &reg_value);
+	if (!(reg_value & MASK_H_LOCK))
+		*status |=  V4L2_IN_ST_NO_H_LOCK;
+	if (!(reg_value & MASK_V_LOCK))
+		*status |=  V4L2_IN_ST_NO_V_LOCK;
+	if (!(reg_value & MASK_STD_LOCK))
+		*status |=  V4L2_IN_ST_NO_STD_LOCK;
+
+	return ret;
+}
+
+static int gs_dv_timings_cap(struct v4l2_subdev *sd,
+			     struct v4l2_dv_timings_cap *cap)
+{
+	if (cap->pad != 0)
+		return -EINVAL;
+
+	*cap = gs_timings_cap;
+	return 0;
+}
+
+/* V4L2 core operation handlers */
+static const struct v4l2_subdev_core_ops gs_core_ops = {
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	.g_register = gs_g_register,
+	.s_register = gs_s_register,
+#endif
+};
+
+static const struct v4l2_subdev_video_ops gs_video_ops = {
+	.s_dv_timings = gs_s_dv_timings,
+	.g_dv_timings = gs_g_dv_timings,
+	.s_stream = gs_s_stream,
+	.g_input_status = gs_g_input_status,
+	.query_dv_timings = gs_query_dv_timings,
+};
+
+static const struct v4l2_subdev_pad_ops gs_pad_ops = {
+	.enum_dv_timings= gs_enum_dv_timings,
+	.dv_timings_cap = gs_dv_timings_cap,
+};
+
+/* V4L2 top level operation handlers */
+static const struct v4l2_subdev_ops gs_ops = {
+	.core = &gs_core_ops,
+	.video = &gs_video_ops,
+	.pad = &gs_pad_ops,
+};
+
+static int gs_probe(struct spi_device *spi)
+{
+	int ret;
+	struct gs *gs;
+	struct v4l2_subdev *sd;
+
+	gs = devm_kzalloc(&spi->dev, sizeof(struct gs), GFP_KERNEL);
+	if (!gs)
+		return -ENOMEM;
+
+	gs->pdev = spi;
+	sd = &gs->sd;
+
+	spi->mode = SPI_MODE_0;
+	spi->irq = -1;
+	spi->max_speed_hz = 10000000;
+	spi->bits_per_word = 16;
+	ret = spi_setup(spi);
+	v4l2_spi_subdev_init(sd, spi, &gs_ops);
+
+	gs->current_timings = reg_fmt[0].format;
+	gs->enabled = 0;
+
+	/* Set H_CONFIG to SMPTE timings */
+	gs_write_register(spi, 0x0, 0x300);
+
+	return ret;
+}
+
+static int gs_remove(struct spi_device *spi)
+{
+	struct v4l2_subdev *sd = spi_get_drvdata(spi);
+	struct gs *gs = to_gs(sd);
+
+	v4l2_device_unregister_subdev(sd);
+	kfree(gs);
+	return 0;
+}
+
+static struct spi_driver gs_driver = {
+	.driver = {
+		.name		= "gs1662",
+		.owner		= THIS_MODULE,
+	},
+
+	.probe		= gs_probe,
+	.remove		= gs_remove,
+	.id_table	= gs_id,
+};
+
+module_spi_driver(gs_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Charles-Antoine Couret <charles-antoine.couret@nexvision.fr>");
+MODULE_DESCRIPTION("Gennum GS1662 HD/SD-SDI Serializer driver");
-- 
2.7.4