[media] shark2: New driver for the Griffin radioSHARK v2 USB radio receiver

This driver consists of 2 parts, a generic tea5777 driver and a driver
for the Griffin radioSHARK v2 USB radio receiver, which is the only driver
using the generic tea5777 for now.

This first version only implements FM support, once the the new
VIDIOC_ENUM_FREQ_BANDS API is upstream I'll also add AM support.

Signed-off-by: Hans de Goede <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/radio/Kconfig

···
 	  To compile this driver as a module, choose M here: the
 	  module will be called radio-shark.
 
+config RADIO_SHARK2
+	tristate "Griffin radioSHARK2 USB radio receiver"
+	depends on USB
+	---help---
+	  Choose Y here if you have this radio receiver.
+
+	  There are 2 versions of this device, this driver is for version 2,
+	  which is black.
+
+	  In order to control your radio card, you will need to use programs
+	  that are compatible with the Video For Linux API.  Information on
+	  this API and pointers to "v4l" programs may be found at
+	  <file:Documentation/video4linux/API.html>.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called radio-shark2.
+
 config I2C_SI4713
 	tristate "I2C driver for Silicon Labs Si4713 device"
 	depends on I2C && VIDEO_V4L2

drivers/media/radio/Makefile

···
 obj-$(CONFIG_RADIO_TERRATEC) += radio-terratec.o
 obj-$(CONFIG_RADIO_MAXIRADIO) += radio-maxiradio.o
 obj-$(CONFIG_RADIO_SHARK) += radio-shark.o
+obj-$(CONFIG_RADIO_SHARK2) += shark2.o
 obj-$(CONFIG_RADIO_RTRACK) += radio-aimslab.o
 obj-$(CONFIG_RADIO_ZOLTRIX) += radio-zoltrix.o
 obj-$(CONFIG_RADIO_GEMTEK) += radio-gemtek.o
···
 obj-$(CONFIG_RADIO_TIMBERDALE) += radio-timb.o
 obj-$(CONFIG_RADIO_WL1273) += radio-wl1273.o
 obj-$(CONFIG_RADIO_WL128X) += wl128x/
+
+shark2-objs := radio-shark2.o radio-tea5777.o
 
 ccflags-y += -Isound

drivers/media/radio/radio-shark2.c

···
+/*
+ * Linux V4L2 radio driver for the Griffin radioSHARK2 USB radio receiver
+ *
+ * Note the radioSHARK2 offers the audio through a regular USB audio device,
+ * this driver only handles the tuning.
+ *
+ * The info necessary to drive the shark2 was taken from the small userspace
+ * shark2.c program by Hisaaki Shibata, which he kindly placed in the Public
+ * Domain.
+ *
+ * Copyright (c) 2012 Hans de Goede <[e-mail]>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/workqueue.h>
+#include <media/v4l2-device.h>
+#include "radio-tea5777.h"
+
+MODULE_AUTHOR("Hans de Goede <[e-mail]>");
+MODULE_DESCRIPTION("Griffin radioSHARK2, USB radio receiver driver");
+MODULE_LICENSE("GPL");
+
+static int debug;
+module_param(debug, int, 0);
+MODULE_PARM_DESC(debug, "Debug level (0-1)");
+
+
+#define SHARK_IN_EP		0x83
+#define SHARK_OUT_EP		0x05
+
+#define TB_LEN 7
+#define DRV_NAME "radioshark2"
+
+#define v4l2_dev_to_shark(d) container_of(d, struct shark_device, v4l2_dev)
+
+enum { BLUE_LED, RED_LED, NO_LEDS };
+
+static void shark_led_set_blue(struct led_classdev *led_cdev,
+			       enum led_brightness value);
+static void shark_led_set_red(struct led_classdev *led_cdev,
+			      enum led_brightness value);
+
+static const struct led_classdev shark_led_templates[NO_LEDS] = {
+	[BLUE_LED] = {
+		.name		= "%s:blue:",
+		.brightness	= LED_OFF,
+		.max_brightness = 127,
+		.brightness_set = shark_led_set_blue,
+	},
+	[RED_LED] = {
+		.name		= "%s:red:",
+		.brightness	= LED_OFF,
+		.max_brightness = 1,
+		.brightness_set = shark_led_set_red,
+	},
+};
+
+struct shark_device {
+	struct usb_device *usbdev;
+	struct v4l2_device v4l2_dev;
+	struct radio_tea5777 tea;
+
+	struct work_struct led_work;
+	struct led_classdev leds[NO_LEDS];
+	char led_names[NO_LEDS][32];
+	atomic_t brightness[NO_LEDS];
+	unsigned long brightness_new;
+
+	u8 *transfer_buffer;
+};
+
+static atomic_t shark_instance = ATOMIC_INIT(0);
+
+static int shark_write_reg(struct radio_tea5777 *tea, u64 reg)
+{
+	struct shark_device *shark = tea->private_data;
+	int i, res, actual_len;
+
+	memset(shark->transfer_buffer, 0, TB_LEN);
+	shark->transfer_buffer[0] = 0x81; /* Write register command */
+	for (i = 0; i < 6; i++)
+		shark->transfer_buffer[i + 1] = (reg >> (40 - i * 8)) & 0xff;
+
+	v4l2_dbg(1, debug, tea->v4l2_dev,
+		 "shark2-write: %02x %02x %02x %02x %02x %02x %02x\n",
+		 shark->transfer_buffer[0], shark->transfer_buffer[1],
+		 shark->transfer_buffer[2], shark->transfer_buffer[3],
+		 shark->transfer_buffer[4], shark->transfer_buffer[5],
+		 shark->transfer_buffer[6]);
+
+	res = usb_interrupt_msg(shark->usbdev,
+				usb_sndintpipe(shark->usbdev, SHARK_OUT_EP),
+				shark->transfer_buffer, TB_LEN,
+				&actual_len, 1000);
+	if (res < 0) {
+		v4l2_err(tea->v4l2_dev, "write error: %d\n", res);
+		return res;
+	}
+
+	return 0;
+}
+
+static int shark_read_reg(struct radio_tea5777 *tea, u32 *reg_ret)
+{
+	struct shark_device *shark = tea->private_data;
+	int i, res, actual_len;
+	u32 reg = 0;
+
+	memset(shark->transfer_buffer, 0, TB_LEN);
+	shark->transfer_buffer[0] = 0x82;
+	res = usb_interrupt_msg(shark->usbdev,
+				usb_sndintpipe(shark->usbdev, SHARK_OUT_EP),
+				shark->transfer_buffer, TB_LEN,
+				&actual_len, 1000);
+	if (res < 0) {
+		v4l2_err(tea->v4l2_dev, "request-read error: %d\n", res);
+		return res;
+	}
+
+	res = usb_interrupt_msg(shark->usbdev,
+				usb_rcvintpipe(shark->usbdev, SHARK_IN_EP),
+				shark->transfer_buffer, TB_LEN,
+				&actual_len, 1000);
+	if (res < 0) {
+		v4l2_err(tea->v4l2_dev, "read error: %d\n", res);
+		return res;
+	}
+
+	for (i = 0; i < 3; i++)
+		reg |= shark->transfer_buffer[i] << (16 - i * 8);
+
+	v4l2_dbg(1, debug, tea->v4l2_dev, "shark2-read: %02x %02x %02x\n",
+		 shark->transfer_buffer[0], shark->transfer_buffer[1],
+		 shark->transfer_buffer[2]);
+
+	*reg_ret = reg;
+	return 0;
+}
+
+static struct radio_tea5777_ops shark_tea_ops = {
+	.write_reg = shark_write_reg,
+	.read_reg  = shark_read_reg,
+};
+
+static void shark_led_work(struct work_struct *work)
+{
+	struct shark_device *shark =
+		container_of(work, struct shark_device, led_work);
+	int i, res, brightness, actual_len;
+	/*
+	 * We use the v4l2_dev lock and registered bit to ensure the device
+	 * does not get unplugged and unreffed while we're running.
+	 */
+	mutex_lock(&shark->tea.mutex);
+	if (!video_is_registered(&shark->tea.vd))
+		goto leave;
+
+	for (i = 0; i < 2; i++) {
+		if (!test_and_clear_bit(i, &shark->brightness_new))
+			continue;
+
+		brightness = atomic_read(&shark->brightness[i]);
+		memset(shark->transfer_buffer, 0, TB_LEN);
+		shark->transfer_buffer[0] = 0x83 + i;
+		shark->transfer_buffer[1] = brightness;
+		res = usb_interrupt_msg(shark->usbdev,
+					usb_sndintpipe(shark->usbdev,
+						       SHARK_OUT_EP),
+					shark->transfer_buffer, TB_LEN,
+					&actual_len, 1000);
+		if (res < 0)
+			v4l2_err(&shark->v4l2_dev, "set LED %s error: %d\n",
+				 shark->led_names[i], res);
+	}
+leave:
+	mutex_unlock(&shark->tea.mutex);
+}
+
+static void shark_led_set_blue(struct led_classdev *led_cdev,
+			       enum led_brightness value)
+{
+	struct shark_device *shark =
+		container_of(led_cdev, struct shark_device, leds[BLUE_LED]);
+
+	atomic_set(&shark->brightness[BLUE_LED], value);
+	set_bit(BLUE_LED, &shark->brightness_new);
+	schedule_work(&shark->led_work);
+}
+
+static void shark_led_set_red(struct led_classdev *led_cdev,
+			      enum led_brightness value)
+{
+	struct shark_device *shark =
+		container_of(led_cdev, struct shark_device, leds[RED_LED]);
+
+	atomic_set(&shark->brightness[RED_LED], value);
+	set_bit(RED_LED, &shark->brightness_new);
+	schedule_work(&shark->led_work);
+}
+
+static void usb_shark_disconnect(struct usb_interface *intf)
+{
+	struct v4l2_device *v4l2_dev = usb_get_intfdata(intf);
+	struct shark_device *shark = v4l2_dev_to_shark(v4l2_dev);
+	int i;
+
+	mutex_lock(&shark->tea.mutex);
+	v4l2_device_disconnect(&shark->v4l2_dev);
+	radio_tea5777_exit(&shark->tea);
+	mutex_unlock(&shark->tea.mutex);
+
+	for (i = 0; i < NO_LEDS; i++)
+		led_classdev_unregister(&shark->leds[i]);
+
+	v4l2_device_put(&shark->v4l2_dev);
+}
+
+static void usb_shark_release(struct v4l2_device *v4l2_dev)
+{
+	struct shark_device *shark = v4l2_dev_to_shark(v4l2_dev);
+
+	cancel_work_sync(&shark->led_work);
+	v4l2_device_unregister(&shark->v4l2_dev);
+	kfree(shark->transfer_buffer);
+	kfree(shark);
+}
+
+static int usb_shark_probe(struct usb_interface *intf,
+			   const struct usb_device_id *id)
+{
+	struct shark_device *shark;
+	int i, retval = -ENOMEM;
+
+	shark = kzalloc(sizeof(struct shark_device), GFP_KERNEL);
+	if (!shark)
+		return retval;
+
+	shark->transfer_buffer = kmalloc(TB_LEN, GFP_KERNEL);
+	if (!shark->transfer_buffer)
+		goto err_alloc_buffer;
+
+	/*
+	 * Work around a bug in usbhid/hid-core.c, where it leaves a dangling
+	 * pointer in intfdata causing v4l2-device.c to not set it. Which
+	 * results in usb_shark_disconnect() referencing the dangling pointer
+	 *
+	 * REMOVE (as soon as the above bug is fixed, patch submitted)
+	 */
+	usb_set_intfdata(intf, NULL);
+
+	shark->v4l2_dev.release = usb_shark_release;
+	v4l2_device_set_name(&shark->v4l2_dev, DRV_NAME, &shark_instance);
+	retval = v4l2_device_register(&intf->dev, &shark->v4l2_dev);
+	if (retval) {
+		v4l2_err(&shark->v4l2_dev, "couldn't register v4l2_device\n");
+		goto err_reg_dev;
+	}
+
+	shark->usbdev = interface_to_usbdev(intf);
+	shark->tea.v4l2_dev = &shark->v4l2_dev;
+	shark->tea.private_data = shark;
+	shark->tea.ops = &shark_tea_ops;
+	shark->tea.has_am = true;
+	shark->tea.write_before_read = true;
+	strlcpy(shark->tea.card, "Griffin radioSHARK2",
+		sizeof(shark->tea.card));
+	usb_make_path(shark->usbdev, shark->tea.bus_info,
+		sizeof(shark->tea.bus_info));
+
+	retval = radio_tea5777_init(&shark->tea, THIS_MODULE);
+	if (retval) {
+		v4l2_err(&shark->v4l2_dev, "couldn't init tea5777\n");
+		goto err_init_tea;
+	}
+
+	INIT_WORK(&shark->led_work, shark_led_work);
+	for (i = 0; i < NO_LEDS; i++) {
+		shark->leds[i] = shark_led_templates[i];
+		snprintf(shark->led_names[i], sizeof(shark->led_names[0]),
+			 shark->leds[i].name, shark->v4l2_dev.name);
+		shark->leds[i].name = shark->led_names[i];
+		/*
+		 * We don't fail the probe if we fail to register the leds,
+		 * because once we've called radio_tea5777_init, the /dev/radio0
+		 * node may be opened from userspace holding a reference to us!
+		 *
+		 * Note we cannot register the leds first instead as
+		 * shark_led_work depends on the v4l2 mutex and registered bit.
+		 */
+		retval = led_classdev_register(&intf->dev, &shark->leds[i]);
+		if (retval)
+			v4l2_err(&shark->v4l2_dev,
+				 "couldn't register led: %s\n",
+				 shark->led_names[i]);
+	}
+
+	return 0;
+
+err_init_tea:
+	v4l2_device_unregister(&shark->v4l2_dev);
+err_reg_dev:
+	kfree(shark->transfer_buffer);
+err_alloc_buffer:
+	kfree(shark);
+
+	return retval;
+}
+
+/* Specify the bcdDevice value, as the radioSHARK and radioSHARK2 share ids */
+static struct usb_device_id usb_shark_device_table[] = {
+	{ .match_flags = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION |
+			 USB_DEVICE_ID_MATCH_INT_CLASS,
+	  .idVendor     = 0x077d,
+	  .idProduct    = 0x627a,
+	  .bcdDevice_lo = 0x0010,
+	  .bcdDevice_hi = 0x0010,
+	  .bInterfaceClass = 3,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(usb, usb_shark_device_table);
+
+static struct usb_driver usb_shark_driver = {
+	.name			= DRV_NAME,
+	.probe			= usb_shark_probe,
+	.disconnect		= usb_shark_disconnect,
+	.id_table		= usb_shark_device_table,
+};
+module_usb_driver(usb_shark_driver);

drivers/media/radio/radio-tea5777.c

···
+/*
+ *   v4l2 driver for TEA5777 Philips AM/FM radio tuner chips
+ *
+ *	Copyright (c) 2012 Hans de Goede <[e-mail]>
+ *
+ *   Based on the ALSA driver for TEA5757/5759 Philips AM/FM radio tuner chips:
+ *
+ *	Copyright (c) 2004 Jaroslav Kysela <[e-mail]>
+ *
+ *   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.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-dev.h>
+#include <media/v4l2-fh.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-event.h>
+#include "radio-tea5777.h"
+
+MODULE_AUTHOR("Hans de Goede <[e-mail]>");
+MODULE_DESCRIPTION("Routines for control of TEA5777 Philips AM/FM radio tuner chips");
+MODULE_LICENSE("GPL");
+
+/* Fixed FM only band for now, will implement multi-band support when the
+   VIDIOC_ENUM_FREQ_BANDS API is upstream */
+#define TEA5777_FM_RANGELOW		(76000 * 16)
+#define TEA5777_FM_RANGEHIGH		(108000 * 16)
+
+#define TEA5777_FM_IF			150 /* kHz */
+#define TEA5777_FM_FREQ_STEP		50 /* kHz */
+
+/* Write reg, common bits */
+#define TEA5777_W_MUTE_MASK		(1LL << 47)
+#define TEA5777_W_MUTE_SHIFT		47
+#define TEA5777_W_AM_FM_MASK		(1LL << 46)
+#define TEA5777_W_AM_FM_SHIFT		46
+#define TEA5777_W_STB_MASK		(1LL << 45)
+#define TEA5777_W_STB_SHIFT		45
+
+#define TEA5777_W_IFCE_MASK		(1LL << 29)
+#define TEA5777_W_IFCE_SHIFT		29
+#define TEA5777_W_IFW_MASK		(1LL << 28)
+#define TEA5777_W_IFW_SHIFT		28
+#define TEA5777_W_HILO_MASK		(1LL << 27)
+#define TEA5777_W_HILO_SHIFT		27
+#define TEA5777_W_DBUS_MASK		(1LL << 26)
+#define TEA5777_W_DBUS_SHIFT		26
+
+#define TEA5777_W_INTEXT_MASK		(1LL << 24)
+#define TEA5777_W_INTEXT_SHIFT		24
+#define TEA5777_W_P1_MASK		(1LL << 23)
+#define TEA5777_W_P1_SHIFT		23
+#define TEA5777_W_P0_MASK		(1LL << 22)
+#define TEA5777_W_P0_SHIFT		22
+#define TEA5777_W_PEN1_MASK		(1LL << 21)
+#define TEA5777_W_PEN1_SHIFT		21
+#define TEA5777_W_PEN0_MASK		(1LL << 20)
+#define TEA5777_W_PEN0_SHIFT		20
+
+#define TEA5777_W_CHP0_MASK		(1LL << 18)
+#define TEA5777_W_CHP0_SHIFT		18
+#define TEA5777_W_DEEM_MASK		(1LL << 17)
+#define TEA5777_W_DEEM_SHIFT		17
+
+#define TEA5777_W_SEARCH_MASK		(1LL << 7)
+#define TEA5777_W_SEARCH_SHIFT		7
+#define TEA5777_W_PROGBLIM_MASK		(1LL << 6)
+#define TEA5777_W_PROGBLIM_SHIFT	6
+#define TEA5777_W_UPDWN_MASK		(1LL << 5)
+#define TEA5777_W_UPDWN_SHIFT		5
+#define TEA5777_W_SLEV_MASK		(3LL << 3)
+#define TEA5777_W_SLEV_SHIFT		3
+
+/* Write reg, FM specific bits */
+#define TEA5777_W_FM_PLL_MASK		(0x1fffLL << 32)
+#define TEA5777_W_FM_PLL_SHIFT		32
+#define TEA5777_W_FM_FREF_MASK		(0x03LL << 30)
+#define TEA5777_W_FM_FREF_SHIFT		30
+#define TEA5777_W_FM_FREF_VALUE		0 /* 50 kHz tune steps, 150 kHz IF */
+
+#define TEA5777_W_FM_FORCEMONO_MASK	(1LL << 15)
+#define TEA5777_W_FM_FORCEMONO_SHIFT	15
+#define TEA5777_W_FM_SDSOFF_MASK	(1LL << 14)
+#define TEA5777_W_FM_SDSOFF_SHIFT	14
+#define TEA5777_W_FM_DOFF_MASK		(1LL << 13)
+#define TEA5777_W_FM_DOFF_SHIFT		13
+
+#define TEA5777_W_FM_STEP_MASK		(3LL << 1)
+#define TEA5777_W_FM_STEP_SHIFT		1
+
+/* Write reg, AM specific bits */
+#define TEA5777_W_AM_PLL_MASK		(0x7ffLL << 34)
+#define TEA5777_W_AM_PLL_SHIFT		34
+#define TEA5777_W_AM_AGCRF_MASK		(1LL << 33)
+#define TEA5777_W_AM_AGCRF_SHIFT	33
+#define TEA5777_W_AM_AGCIF_MASK		(1LL << 32)
+#define TEA5777_W_AM_AGCIF_SHIFT	32
+#define TEA5777_W_AM_MWLW_MASK		(1LL << 31)
+#define TEA5777_W_AM_MWLW_SHIFT		31
+#define TEA5777_W_AM_LNA_MASK		(1LL << 30)
+#define TEA5777_W_AM_LNA_SHIFT		30
+
+#define TEA5777_W_AM_PEAK_MASK		(1LL << 25)
+#define TEA5777_W_AM_PEAK_SHIFT		25
+
+#define TEA5777_W_AM_RFB_MASK		(1LL << 16)
+#define TEA5777_W_AM_RFB_SHIFT		16
+#define TEA5777_W_AM_CALLIGN_MASK	(1LL << 15)
+#define TEA5777_W_AM_CALLIGN_SHIFT	15
+#define TEA5777_W_AM_CBANK_MASK		(0x7fLL << 8)
+#define TEA5777_W_AM_CBANK_SHIFT	8
+
+#define TEA5777_W_AM_DELAY_MASK		(1LL << 2)
+#define TEA5777_W_AM_DELAY_SHIFT	2
+#define TEA5777_W_AM_STEP_MASK		(1LL << 1)
+#define TEA5777_W_AM_STEP_SHIFT		1
+
+/* Read reg, common bits */
+#define TEA5777_R_LEVEL_MASK		(0x0f << 17)
+#define TEA5777_R_LEVEL_SHIFT		17
+#define TEA5777_R_SFOUND_MASK		(0x01 << 16)
+#define TEA5777_R_SFOUND_SHIFT		16
+#define TEA5777_R_BLIM_MASK		(0x01 << 15)
+#define TEA5777_R_BLIM_SHIFT		15
+
+/* Read reg, FM specific bits */
+#define TEA5777_R_FM_STEREO_MASK	(0x01 << 21)
+#define TEA5777_R_FM_STEREO_SHIFT	21
+#define TEA5777_R_FM_PLL_MASK		0x1fff
+#define TEA5777_R_FM_PLL_SHIFT		0
+
+static u32 tea5777_freq_to_v4l2_freq(struct radio_tea5777 *tea, u32 freq)
+{
+	return (freq * TEA5777_FM_FREQ_STEP + TEA5777_FM_IF) * 16;
+}
+
+static int radio_tea5777_set_freq(struct radio_tea5777 *tea)
+{
+	u64 freq;
+	int res;
+
+	freq = clamp_t(u32, tea->freq,
+		       TEA5777_FM_RANGELOW, TEA5777_FM_RANGEHIGH);
+	freq = (freq + 8) / 16; /* to kHz */
+
+	freq = (freq - TEA5777_FM_IF) / TEA5777_FM_FREQ_STEP;
+
+	tea->write_reg &= ~(TEA5777_W_FM_PLL_MASK | TEA5777_W_FM_FREF_MASK);
+	tea->write_reg |= freq << TEA5777_W_FM_PLL_SHIFT;
+	tea->write_reg |= TEA5777_W_FM_FREF_VALUE << TEA5777_W_FM_FREF_SHIFT;
+
+	res = tea->ops->write_reg(tea, tea->write_reg);
+	if (res)
+		return res;
+
+	tea->needs_write = false;
+	tea->read_reg = -1;
+	tea->freq = tea5777_freq_to_v4l2_freq(tea, freq);
+
+	return 0;
+}
+
+static int radio_tea5777_update_read_reg(struct radio_tea5777 *tea, int wait)
+{
+	int res;
+
+	if (tea->read_reg != -1)
+		return 0;
+
+	if (tea->write_before_read && tea->needs_write) {
+		res = radio_tea5777_set_freq(tea);
+		if (res)
+			return res;
+	}
+
+	if (wait) {
+		if (schedule_timeout_interruptible(msecs_to_jiffies(wait)))
+			return -ERESTARTSYS;
+	}
+
+	res = tea->ops->read_reg(tea, &tea->read_reg);
+	if (res)
+		return res;
+
+	tea->needs_write = true;
+	return 0;
+}
+
+/*
+ * Linux Video interface
+ */
+
+static int vidioc_querycap(struct file *file, void  *priv,
+					struct v4l2_capability *v)
+{
+	struct radio_tea5777 *tea = video_drvdata(file);
+
+	strlcpy(v->driver, tea->v4l2_dev->name, sizeof(v->driver));
+	strlcpy(v->card, tea->card, sizeof(v->card));
+	strlcat(v->card, " TEA5777", sizeof(v->card));
+	strlcpy(v->bus_info, tea->bus_info, sizeof(v->bus_info));
+	v->device_caps = V4L2_CAP_TUNER | V4L2_CAP_RADIO;
+	v->device_caps |= V4L2_CAP_HW_FREQ_SEEK;
+	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
+	return 0;
+}
+
+static int vidioc_g_tuner(struct file *file, void *priv,
+					struct v4l2_tuner *v)
+{
+	struct radio_tea5777 *tea = video_drvdata(file);
+	int res;
+
+	if (v->index > 0)
+		return -EINVAL;
+
+	res = radio_tea5777_update_read_reg(tea, 0);
+	if (res)
+		return res;
+
+	memset(v, 0, sizeof(*v));
+	if (tea->has_am)
+		strlcpy(v->name, "AM/FM", sizeof(v->name));
+	else
+		strlcpy(v->name, "FM", sizeof(v->name));
+	v->type = V4L2_TUNER_RADIO;
+	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
+			V4L2_TUNER_CAP_HWSEEK_BOUNDED;
+	v->rangelow   = TEA5777_FM_RANGELOW;
+	v->rangehigh  = TEA5777_FM_RANGEHIGH;
+	v->rxsubchans = (tea->read_reg & TEA5777_R_FM_STEREO_MASK) ?
+			V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO;
+	v->audmode = (tea->write_reg & TEA5777_W_FM_FORCEMONO_MASK) ?
+		V4L2_TUNER_MODE_MONO : V4L2_TUNER_MODE_STEREO;
+	/* shift - 12 to convert 4-bits (0-15) scale to 16-bits (0-65535) */
+	v->signal = (tea->read_reg & TEA5777_R_LEVEL_MASK) >>
+		    (TEA5777_R_LEVEL_SHIFT - 12);
+
+	/* Invalidate read_reg, so that next call we return up2date signal */
+	tea->read_reg = -1;
+
+	return 0;
+}
+
+static int vidioc_s_tuner(struct file *file, void *priv,
+					struct v4l2_tuner *v)
+{
+	struct radio_tea5777 *tea = video_drvdata(file);
+
+	if (v->index)
+		return -EINVAL;
+
+	if (v->audmode == V4L2_TUNER_MODE_MONO)
+		tea->write_reg |= TEA5777_W_FM_FORCEMONO_MASK;
+	else
+		tea->write_reg &= ~TEA5777_W_FM_FORCEMONO_MASK;
+
+	return radio_tea5777_set_freq(tea);
+}
+
+static int vidioc_g_frequency(struct file *file, void *priv,
+					struct v4l2_frequency *f)
+{
+	struct radio_tea5777 *tea = video_drvdata(file);
+
+	if (f->tuner != 0)
+		return -EINVAL;
+	f->type = V4L2_TUNER_RADIO;
+	f->frequency = tea->freq;
+	return 0;
+}
+
+static int vidioc_s_frequency(struct file *file, void *priv,
+					struct v4l2_frequency *f)
+{
+	struct radio_tea5777 *tea = video_drvdata(file);
+
+	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
+		return -EINVAL;
+
+	tea->freq = f->frequency;
+	return radio_tea5777_set_freq(tea);
+}
+
+static int vidioc_s_hw_freq_seek(struct file *file, void *fh,
+					struct v4l2_hw_freq_seek *a)
+{
+	struct radio_tea5777 *tea = video_drvdata(file);
+	u32 orig_freq = tea->freq;
+	unsigned long timeout;
+	int res, spacing = 200 * 16; /* 200 kHz */
+	/* These are fixed *for now* */
+	const u32 seek_rangelow  = TEA5777_FM_RANGELOW;
+	const u32 seek_rangehigh = TEA5777_FM_RANGEHIGH;
+
+	if (a->tuner || a->wrap_around)
+		return -EINVAL;
+
+	tea->write_reg |= TEA5777_W_PROGBLIM_MASK;
+	if (seek_rangelow != tea->seek_rangelow) {
+		tea->write_reg &= ~TEA5777_W_UPDWN_MASK;
+		tea->freq = seek_rangelow;
+		res = radio_tea5777_set_freq(tea);
+		if (res)
+			goto leave;
+		tea->seek_rangelow = tea->freq;
+	}
+	if (seek_rangehigh != tea->seek_rangehigh) {
+		tea->write_reg |= TEA5777_W_UPDWN_MASK;
+		tea->freq = seek_rangehigh;
+		res = radio_tea5777_set_freq(tea);
+		if (res)
+			goto leave;
+		tea->seek_rangehigh = tea->freq;
+	}
+	tea->write_reg &= ~TEA5777_W_PROGBLIM_MASK;
+
+	tea->write_reg |= TEA5777_W_SEARCH_MASK;
+	if (a->seek_upward) {
+		tea->write_reg |= TEA5777_W_UPDWN_MASK;
+		tea->freq = orig_freq + spacing;
+	} else {
+		tea->write_reg &= ~TEA5777_W_UPDWN_MASK;
+		tea->freq = orig_freq - spacing;
+	}
+	res = radio_tea5777_set_freq(tea);
+	if (res)
+		goto leave;
+
+	timeout = jiffies + msecs_to_jiffies(5000);
+	for (;;) {
+		if (time_after(jiffies, timeout)) {
+			res = -ENODATA;
+			break;
+		}
+
+		res = radio_tea5777_update_read_reg(tea, 100);
+		if (res)
+			break;
+
+		/*
+		 * Note we use tea->freq to track how far we've searched sofar
+		 * this is necessary to ensure we continue seeking at the right
+		 * point, in the write_before_read case.
+		 */
+		tea->freq = (tea->read_reg & TEA5777_R_FM_PLL_MASK);
+		tea->freq = tea5777_freq_to_v4l2_freq(tea, tea->freq);
+
+		if ((tea->read_reg & TEA5777_R_SFOUND_MASK)) {
+			tea->write_reg &= ~TEA5777_W_SEARCH_MASK;
+			return 0;
+		}
+
+		if (tea->read_reg & TEA5777_R_BLIM_MASK) {
+			res = -ENODATA;
+			break;
+		}
+
+		/* Force read_reg update */
+		tea->read_reg = -1;
+	}
+leave:
+	tea->write_reg &= ~TEA5777_W_PROGBLIM_MASK;
+	tea->write_reg &= ~TEA5777_W_SEARCH_MASK;
+	tea->freq = orig_freq;
+	radio_tea5777_set_freq(tea);
+	return res;
+}
+
+static int tea575x_s_ctrl(struct v4l2_ctrl *c)
+{
+	struct radio_tea5777 *tea =
+		container_of(c->handler, struct radio_tea5777, ctrl_handler);
+
+	switch (c->id) {
+	case V4L2_CID_AUDIO_MUTE:
+		if (c->val)
+			tea->write_reg |= TEA5777_W_MUTE_MASK;
+		else
+			tea->write_reg &= ~TEA5777_W_MUTE_MASK;
+
+		return radio_tea5777_set_freq(tea);
+	}
+
+	return -EINVAL;
+}
+
+static const struct v4l2_file_operations tea575x_fops = {
+	.unlocked_ioctl	= video_ioctl2,
+	.open		= v4l2_fh_open,
+	.release	= v4l2_fh_release,
+	.poll		= v4l2_ctrl_poll,
+};
+
+static const struct v4l2_ioctl_ops tea575x_ioctl_ops = {
+	.vidioc_querycap    = vidioc_querycap,
+	.vidioc_g_tuner     = vidioc_g_tuner,
+	.vidioc_s_tuner     = vidioc_s_tuner,
+	.vidioc_g_frequency = vidioc_g_frequency,
+	.vidioc_s_frequency = vidioc_s_frequency,
+	.vidioc_s_hw_freq_seek = vidioc_s_hw_freq_seek,
+	.vidioc_log_status  = v4l2_ctrl_log_status,
+	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
+	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
+};
+
+static const struct video_device tea575x_radio = {
+	.ioctl_ops	= &tea575x_ioctl_ops,
+	.release	= video_device_release_empty,
+};
+
+static const struct v4l2_ctrl_ops tea575x_ctrl_ops = {
+	.s_ctrl = tea575x_s_ctrl,
+};
+
+int radio_tea5777_init(struct radio_tea5777 *tea, struct module *owner)
+{
+	int res;
+
+	tea->write_reg = (1LL << TEA5777_W_IFCE_SHIFT) |
+			 (1LL << TEA5777_W_IFW_SHIFT) |
+			 (1LL << TEA5777_W_INTEXT_SHIFT) |
+			 (1LL << TEA5777_W_CHP0_SHIFT) |
+			 (2LL << TEA5777_W_SLEV_SHIFT);
+	tea->freq = 90500 * 16;	/* 90.5Mhz default */
+	res = radio_tea5777_set_freq(tea);
+	if (res) {
+		v4l2_err(tea->v4l2_dev, "can't set initial freq (%d)\n", res);
+		return res;
+	}
+
+	tea->vd = tea575x_radio;
+	video_set_drvdata(&tea->vd, tea);
+	mutex_init(&tea->mutex);
+	strlcpy(tea->vd.name, tea->v4l2_dev->name, sizeof(tea->vd.name));
+	tea->vd.lock = &tea->mutex;
+	tea->vd.v4l2_dev = tea->v4l2_dev;
+	tea->fops = tea575x_fops;
+	tea->fops.owner = owner;
+	tea->vd.fops = &tea->fops;
+	set_bit(V4L2_FL_USE_FH_PRIO, &tea->vd.flags);
+
+	tea->vd.ctrl_handler = &tea->ctrl_handler;
+	v4l2_ctrl_handler_init(&tea->ctrl_handler, 1);
+	v4l2_ctrl_new_std(&tea->ctrl_handler, &tea575x_ctrl_ops,
+			  V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
+	res = tea->ctrl_handler.error;
+	if (res) {
+		v4l2_err(tea->v4l2_dev, "can't initialize controls\n");
+		v4l2_ctrl_handler_free(&tea->ctrl_handler);
+		return res;
+	}
+	v4l2_ctrl_handler_setup(&tea->ctrl_handler);
+
+	res = video_register_device(&tea->vd, VFL_TYPE_RADIO, -1);
+	if (res) {
+		v4l2_err(tea->v4l2_dev, "can't register video device!\n");
+		v4l2_ctrl_handler_free(tea->vd.ctrl_handler);
+		return res;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(radio_tea5777_init);
+
+void radio_tea5777_exit(struct radio_tea5777 *tea)
+{
+	video_unregister_device(&tea->vd);
+	v4l2_ctrl_handler_free(tea->vd.ctrl_handler);
+}
+EXPORT_SYMBOL_GPL(radio_tea5777_exit);

drivers/media/radio/radio-tea5777.h

···
+#ifndef __RADIO_TEA5777_H
+#define __RADIO_TEA5777_H
+
+/*
+ *   v4l2 driver for TEA5777 Philips AM/FM radio tuner chips
+ *
+ *	Copyright (c) 2012 Hans de Goede <[e-mail]>
+ *
+ *   Based on the ALSA driver for TEA5757/5759 Philips AM/FM radio tuner chips:
+ *
+ *	Copyright (c) 2004 Jaroslav Kysela <[e-mail]>
+ *	Copyright (c) 2012 Hans de Goede <[e-mail]>
+ *
+ *   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.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/videodev2.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-dev.h>
+#include <media/v4l2-device.h>
+
+#define TEA575X_FMIF	10700
+#define TEA575X_AMIF	  450
+
+struct radio_tea5777;
+
+struct radio_tea5777_ops {
+	/*
+	 * Write the 6 bytes large write register of the tea5777
+	 *
+	 * val represents the 6 write registers, with byte 1 from the
+	 * datasheet being the most significant byte (so byte 5 of the u64),
+	 * and byte 6 from the datasheet being the least significant byte.
+	 *
+	 * returns 0 on success.
+	 */
+	int (*write_reg)(struct radio_tea5777 *tea, u64 val);
+	/*
+	 * Read the 3 bytes large read register of the tea5777
+	 *
+	 * The read value gets returned in val, akin to write_reg, byte 1 from
+	 * the datasheet is stored as the most significant byte (so byte 2 of
+	 * the u32), and byte 3 from the datasheet gets stored as the least
+	 * significant byte (iow byte 0 of the u32).
+	 *
+	 * returns 0 on success.
+	 */
+	int (*read_reg)(struct radio_tea5777 *tea, u32 *val);
+};
+
+struct radio_tea5777 {
+	struct v4l2_device *v4l2_dev;
+	struct v4l2_file_operations fops;
+	struct video_device vd;		/* video device */
+	bool has_am;			/* Device can tune to AM freqs */
+	bool write_before_read;		/* must write before read quirk */
+	bool needs_write;		/* for write before read quirk */
+	u32 freq;			/* current frequency */
+	u32 seek_rangelow;		/* current hwseek limits */
+	u32 seek_rangehigh;
+	u32 read_reg;
+	u64 write_reg;
+	struct mutex mutex;
+	struct radio_tea5777_ops *ops;
+	void *private_data;
+	u8 card[32];
+	u8 bus_info[32];
+	struct v4l2_ctrl_handler ctrl_handler;
+};
+
+int radio_tea5777_init(struct radio_tea5777 *tea, struct module *owner);
+void radio_tea5777_exit(struct radio_tea5777 *tea);
+
+#endif /* __RADIO_TEA5777_H */