V4L/DVB (11742): TI THS7303 video amplifier driver code

This patch adds driver for TI THS7303 video amplifier. This driver is
implemented as a v4l2 sub device. Tested on TI DM646x EVM.

This version has updates based on review comments by Mauro Chehab.
Signed-off-by: Chaithrika U S <chaithrika@ti.com>
Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/Kconfig

@@ -440,6 +440,15 @@ config VIDEO_ADV7175
 	  To compile this driver as a module, choose M here: the
 	  module will be called adv7175.
 
+config VIDEO_THS7303
+	tristate "THS7303 Video Amplifier"
+	depends on I2C
+	help
+	  Support for TI THS7303 video amplifier
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ths7303.
+
 comment "Video improvement chips"
 
 config VIDEO_UPD64031A

drivers/media/video/Makefile

@@ -54,6 +54,7 @@ obj-$(CONFIG_VIDEO_BT819) += bt819.o
 obj-$(CONFIG_VIDEO_BT856) += bt856.o
 obj-$(CONFIG_VIDEO_BT866) += bt866.o
 obj-$(CONFIG_VIDEO_KS0127) += ks0127.o
+obj-$(CONFIG_VIDEO_THS7303) += ths7303.o
 
 obj-$(CONFIG_VIDEO_ZORAN) += zoran/
 

drivers/media/video/ths7303.c

+/*
+ * ths7303- THS7303 Video Amplifier driver
+ *
+ * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * 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 version 2.
+ *
+ * This program is distributed .as is. WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/ctype.h>
+#include <linux/i2c.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/videodev2.h>
+
+#include <media/v4l2-device.h>
+#include <media/v4l2-subdev.h>
+#include <media/v4l2-chip-ident.h>
+
+MODULE_DESCRIPTION("TI THS7303 video amplifier driver");
+MODULE_AUTHOR("Chaithrika U S");
+MODULE_LICENSE("GPL");
+
+static int debug;
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "Debug level 0-1");
+
+/* following function is used to set ths7303 */
+static int ths7303_setvalue(struct v4l2_subdev *sd, v4l2_std_id std)
+{
+	int err = 0;
+	u8 val;
+	struct i2c_client *client;
+
+	client = v4l2_get_subdevdata(sd);
+
+	if (std & (V4L2_STD_ALL & ~V4L2_STD_SECAM)) {
+		val = 0x02;
+		v4l2_dbg(1, debug, sd, "setting value for SDTV format\n");
+	} else {
+		val = 0x00;
+		v4l2_dbg(1, debug, sd, "disabling all channels\n");
+	}
+
+	err |= i2c_smbus_write_byte_data(client, 0x01, val);
+	err |= i2c_smbus_write_byte_data(client, 0x02, val);
+	err |= i2c_smbus_write_byte_data(client, 0x03, val);
+
+	if (err)
+		v4l2_err(sd, "write failed\n");
+
+	return err;
+}
+
+static int ths7303_s_std_output(struct v4l2_subdev *sd, v4l2_std_id norm)
+{
+	return ths7303_setvalue(sd, norm);
+}
+
+static int ths7303_g_chip_ident(struct v4l2_subdev *sd,
+				struct v4l2_dbg_chip_ident *chip)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	return v4l2_chip_ident_i2c_client(client, chip, V4L2_IDENT_THS7303, 0);
+}
+
+static const struct v4l2_subdev_video_ops ths7303_video_ops = {
+	.s_std_output	= ths7303_s_std_output,
+};
+
+static const struct v4l2_subdev_core_ops ths7303_core_ops = {
+	.g_chip_ident = ths7303_g_chip_ident,
+};
+
+static const struct v4l2_subdev_ops ths7303_ops = {
+	.core	= &ths7303_core_ops,
+	.video 	= &ths7303_video_ops,
+};
+
+static int ths7303_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct v4l2_subdev *sd;
+	v4l2_std_id std_id = V4L2_STD_NTSC;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -ENODEV;
+
+	v4l_info(client, "chip found @ 0x%x (%s)\n",
+			client->addr << 1, client->adapter->name);
+
+	sd = kzalloc(sizeof(struct v4l2_subdev), GFP_KERNEL);
+	if (sd == NULL)
+		return -ENOMEM;
+
+	v4l2_i2c_subdev_init(sd, client, &ths7303_ops);
+
+	return ths7303_setvalue(sd, std_id);
+}
+
+static int ths7303_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+
+	v4l2_device_unregister_subdev(sd);
+	kfree(sd);
+
+	return 0;
+}
+
+static const struct i2c_device_id ths7303_id[] = {
+	{"ths7303", 0},
+	{},
+};
+
+MODULE_DEVICE_TABLE(i2c, ths7303_id);
+
+static struct i2c_driver ths7303_driver = {
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= "ths7303",
+	},
+	.probe		= ths7303_probe,
+	.remove		= ths7303_remove,
+	.id_table	= ths7303_id,
+};
+
+static int __init ths7303_init(void)
+{
+	return i2c_add_driver(&ths7303_driver);
+}
+
+static void __exit ths7303_exit(void)
+{
+	i2c_del_driver(&ths7303_driver);
+}
+
+module_init(ths7303_init);
+module_exit(ths7303_exit);
+

include/media/v4l2-chip-ident.h

@@ -137,6 +137,9 @@ enum {
 	/* module saa7191: just ident 7191 */
 	V4L2_IDENT_SAA7191 = 7191,
 
+	/* module ths7303: just ident 7303 */
+	V4L2_IDENT_THS7303 = 7303,
+
 	/* module wm8739: just ident 8739 */
 	V4L2_IDENT_WM8739 = 8739,