radio-platform-si4713.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * drivers/media/radio/radio-si4713.c
  4 *
  5 * Platform Driver for Silicon Labs Si4713 FM Radio Transmitter:
  6 *
  7 * Copyright (c) 2008 Instituto Nokia de Tecnologia - INdT
  8 * Contact: Eduardo Valentin <eduardo.valentin@nokia.com>
  9 */
 10
 11#include <linux/kernel.h>
 12#include <linux/module.h>
 13#include <linux/init.h>
 14#include <linux/platform_device.h>
 15#include <linux/i2c.h>
 16#include <linux/videodev2.h>
 17#include <linux/slab.h>
 18#include <media/v4l2-device.h>
 19#include <media/v4l2-common.h>
 20#include <media/v4l2-ioctl.h>
 21#include <media/v4l2-fh.h>
 22#include <media/v4l2-ctrls.h>
 23#include <media/v4l2-event.h>
 24#include "si4713.h"
 25
 26/* module parameters */
 27static int radio_nr = -1;	/* radio device minor (-1 ==> auto assign) */
 28module_param(radio_nr, int, 0);
 29MODULE_PARM_DESC(radio_nr,
 30		 "Minor number for radio device (-1 ==> auto assign)");
 31
 32MODULE_LICENSE("GPL v2");
 33MODULE_AUTHOR("Eduardo Valentin <eduardo.valentin@nokia.com>");
 34MODULE_DESCRIPTION("Platform driver for Si4713 FM Radio Transmitter");
 35MODULE_VERSION("0.0.1");
 36MODULE_ALIAS("platform:radio-si4713");
 37
 38/* Driver state struct */
 39struct radio_si4713_device {
 40	struct v4l2_device		v4l2_dev;
 41	struct video_device		radio_dev;
 42	struct mutex lock;
 43};
 44
 45/* radio_si4713_fops - file operations interface */
 46static const struct v4l2_file_operations radio_si4713_fops = {
 47	.owner		= THIS_MODULE,
 48	.open = v4l2_fh_open,
 49	.release = v4l2_fh_release,
 50	.poll = v4l2_ctrl_poll,
 51	/* Note: locking is done at the subdev level in the i2c driver. */
 52	.unlocked_ioctl	= video_ioctl2,
 53};
 54
 55/* Video4Linux Interface */
 56
 57/* radio_si4713_querycap - query device capabilities */
 58static int radio_si4713_querycap(struct file *file, void *priv,
 59					struct v4l2_capability *capability)
 60{
 61	strscpy(capability->driver, "radio-si4713", sizeof(capability->driver));
 62	strscpy(capability->card, "Silicon Labs Si4713 Modulator",
 63		sizeof(capability->card));
 64	strscpy(capability->bus_info, "platform:radio-si4713",
 65		sizeof(capability->bus_info));
 66	return 0;
 67}
 68
 69/*
 70 * v4l2 ioctl call backs.
 71 * we are just a wrapper for v4l2_sub_devs.
 72 */
 73static inline struct v4l2_device *get_v4l2_dev(struct file *file)
 74{
 75	return &((struct radio_si4713_device *)video_drvdata(file))->v4l2_dev;
 76}
 77
 78static int radio_si4713_g_modulator(struct file *file, void *priv,
 79				    struct v4l2_modulator *vm)
 80{
 81	return v4l2_device_call_until_err(get_v4l2_dev(file), 0, tuner,
 82					  g_modulator, vm);
 83}
 84
 85static int radio_si4713_s_modulator(struct file *file, void *priv,
 86				    const struct v4l2_modulator *vm)
 87{
 88	return v4l2_device_call_until_err(get_v4l2_dev(file), 0, tuner,
 89					  s_modulator, vm);
 90}
 91
 92static int radio_si4713_g_frequency(struct file *file, void *priv,
 93				    struct v4l2_frequency *vf)
 94{
 95	return v4l2_device_call_until_err(get_v4l2_dev(file), 0, tuner,
 96					  g_frequency, vf);
 97}
 98
 99static int radio_si4713_s_frequency(struct file *file, void *priv,
100				    const struct v4l2_frequency *vf)
101{
102	return v4l2_device_call_until_err(get_v4l2_dev(file), 0, tuner,
103					  s_frequency, vf);
104}
105
106static long radio_si4713_default(struct file *file, void *priv,
107				 bool valid_prio, unsigned int cmd, void *arg)
108{
109	return v4l2_device_call_until_err(get_v4l2_dev(file), 0, core,
110					  ioctl, cmd, arg);
111}
112
113static const struct v4l2_ioctl_ops radio_si4713_ioctl_ops = {
114	.vidioc_querycap	= radio_si4713_querycap,
115	.vidioc_g_modulator	= radio_si4713_g_modulator,
116	.vidioc_s_modulator	= radio_si4713_s_modulator,
117	.vidioc_g_frequency	= radio_si4713_g_frequency,
118	.vidioc_s_frequency	= radio_si4713_s_frequency,
119	.vidioc_log_status      = v4l2_ctrl_log_status,
120	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
121	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
122	.vidioc_default		= radio_si4713_default,
123};
124
125/* radio_si4713_vdev_template - video device interface */
126static const struct video_device radio_si4713_vdev_template = {
127	.fops			= &radio_si4713_fops,
128	.name			= "radio-si4713",
129	.release		= video_device_release_empty,
130	.ioctl_ops		= &radio_si4713_ioctl_ops,
131	.vfl_dir		= VFL_DIR_TX,
132};
133
134/* Platform driver interface */
135/* radio_si4713_pdriver_probe - probe for the device */
136static int radio_si4713_pdriver_probe(struct platform_device *pdev)
137{
138	struct radio_si4713_platform_data *pdata = pdev->dev.platform_data;
139	struct radio_si4713_device *rsdev;
140	struct v4l2_subdev *sd;
141	int rval = 0;
142
143	if (!pdata) {
144		dev_err(&pdev->dev, "Cannot proceed without platform data.\n");
145		rval = -EINVAL;
146		goto exit;
147	}
148
149	rsdev = devm_kzalloc(&pdev->dev, sizeof(*rsdev), GFP_KERNEL);
150	if (!rsdev) {
151		dev_err(&pdev->dev, "Failed to alloc video device.\n");
152		rval = -ENOMEM;
153		goto exit;
154	}
155	mutex_init(&rsdev->lock);
156
157	rval = v4l2_device_register(&pdev->dev, &rsdev->v4l2_dev);
158	if (rval) {
159		dev_err(&pdev->dev, "Failed to register v4l2 device.\n");
160		goto exit;
161	}
162
163	sd = i2c_get_clientdata(pdata->subdev);
164	rval = v4l2_device_register_subdev(&rsdev->v4l2_dev, sd);
165	if (rval) {
166		dev_err(&pdev->dev, "Cannot get v4l2 subdevice\n");
167		goto unregister_v4l2_dev;
168	}
169
170	rsdev->radio_dev = radio_si4713_vdev_template;
171	rsdev->radio_dev.v4l2_dev = &rsdev->v4l2_dev;
172	rsdev->radio_dev.ctrl_handler = sd->ctrl_handler;
173	/* Serialize all access to the si4713 */
174	rsdev->radio_dev.lock = &rsdev->lock;
175	rsdev->radio_dev.device_caps = V4L2_CAP_MODULATOR | V4L2_CAP_RDS_OUTPUT;
176	video_set_drvdata(&rsdev->radio_dev, rsdev);
177	if (video_register_device(&rsdev->radio_dev, VFL_TYPE_RADIO, radio_nr)) {
178		dev_err(&pdev->dev, "Could not register video device.\n");
179		rval = -EIO;
180		goto unregister_v4l2_dev;
181	}
182	dev_info(&pdev->dev, "New device successfully probed\n");
183
184	goto exit;
185
186unregister_v4l2_dev:
187	v4l2_device_unregister(&rsdev->v4l2_dev);
188exit:
189	return rval;
190}
191
192/* radio_si4713_pdriver_remove - remove the device */
193static void radio_si4713_pdriver_remove(struct platform_device *pdev)
194{
195	struct v4l2_device *v4l2_dev = platform_get_drvdata(pdev);
196	struct radio_si4713_device *rsdev;
197
198	rsdev = container_of(v4l2_dev, struct radio_si4713_device, v4l2_dev);
199	video_unregister_device(&rsdev->radio_dev);
200	v4l2_device_unregister(&rsdev->v4l2_dev);
201}
202
203static struct platform_driver radio_si4713_pdriver = {
204	.driver		= {
205		.name	= "radio-si4713",
206	},
207	.probe		= radio_si4713_pdriver_probe,
208	.remove         = radio_si4713_pdriver_remove,
209};
210
211module_platform_driver(radio_si4713_pdriver);