Re: [PATCH 1/1] media: dvb_dummy_tuner: implement driver skeleton

Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> · Thu, 9 Jan 2020 09:45:33 -0700

Hi Daniel,

On 1/9/20 8:24 AM, Daniel W. S. Almeida wrote:
From: "Daniel W. S. Almeida" <dwlsalmeida@xxxxxxxxx>

Implement the skeleton for the tuner driver in a separate file.

Please add more detail here on what this driver does. What this
driver is used for and so on.


Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@xxxxxxxxx>
---
  drivers/media/tuners/Kconfig           |   7 ++
  drivers/media/tuners/Makefile          |   1 +
  drivers/media/tuners/dvb_dummy_tuner.c | 153 +++++++++++++++++++++++++
  drivers/media/tuners/dvb_dummy_tuner.h |  20 ++++
  4 files changed, 181 insertions(+)
  create mode 100644 drivers/media/tuners/dvb_dummy_tuner.c
  create mode 100644 drivers/media/tuners/dvb_dummy_tuner.h

diff --git a/drivers/media/tuners/Kconfig b/drivers/media/tuners/Kconfig
index e104bb7766e1..efa1591fe0ae 100644
--- a/drivers/media/tuners/Kconfig
+++ b/drivers/media/tuners/Kconfig
@@ -296,4 +296,11 @@ config MEDIA_TUNER_QM1D1B0004
  	default m if !MEDIA_SUBDRV_AUTOSELECT
  	help
  	  Sharp QM1D1B0004 ISDB-S tuner driver.
+
+config MEDIA_TUNER_DVB_DUMMY_TUNER
+	tristate "Dummy tuner"
+	depends on MEDIA_SUPPORT && I2C
+	default m if !MEDIA_SUBDRV_AUTOSELECT
+	help
+	  Dummy tuner driver for common TV standards.

Samehere. Give more details on what this driver does. Add enough detail
to help users decide why they should enable it or not.

  endmenu
diff --git a/drivers/media/tuners/Makefile b/drivers/media/tuners/Makefile
index 7b4f8423501e..f98de1cf2e19 100644
--- a/drivers/media/tuners/Makefile
+++ b/drivers/media/tuners/Makefile
@@ -44,5 +44,6 @@ obj-$(CONFIG_MEDIA_TUNER_QM1D1C0042) += qm1d1c0042.o
  obj-$(CONFIG_MEDIA_TUNER_QM1D1B0004) += qm1d1b0004.o
  obj-$(CONFIG_MEDIA_TUNER_M88RS6000T) += m88rs6000t.o
  obj-$(CONFIG_MEDIA_TUNER_TDA18250) += tda18250.o
+obj-$(CONFIG_MEDIA_TUNER_DVB_DUMMY_TUNER) += dvb_dummy_tuner.o
  
  ccflags-y += -I$(srctree)/drivers/media/dvb-frontends
diff --git a/drivers/media/tuners/dvb_dummy_tuner.c b/drivers/media/tuners/dvb_dummy_tuner.c
new file mode 100644
index 000000000000..63d2e47d4739
--- /dev/null
+++ b/drivers/media/tuners/dvb_dummy_tuner.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Driver for Dummy Frontend
+ *
+ *  Written by Daniel W. S. Almeida <dwlsalmeida@xxxxxxxxx>

General practice is the following.

Copyright (c) 2020 Daniel W. S. Almeida <dwlsalmeida@xxxxxxxxx>

+ */
+
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <media/dvb_frontend.h>
+#include "dvb_dummy_tuner.h"
+
+struct dvb_dummy_tuner_dev {
+	struct dvb_frontend *fe;
+};
+
+static void dvb_dummy_tuner_release(struct dvb_frontend *fe)
+{
+}
+
+static int dvb_dummy_tuner_init(struct dvb_frontend *fe)
+{
+	return 0;
+}
+
+static int dvb_dummy_tuner_sleep(struct dvb_frontend *fe)
+{
+	return 0;
+}
+
+static int dvb_dummy_tuner_suspend(struct dvb_frontend *fe)
+{
+	return 0;
+}
+
+static int dvb_dummy_tuner_resume(struct dvb_frontend *fe)
+{
+	return 0;
+}
+
+static int dvb_dummy_tuner_set_params(struct dvb_frontend *fe)
+{
+	return 0;
+}
+
+static int dvb_dummy_tuner_set_config(struct dvb_frontend *fe, void *priv_cfg)
+{
+	return 0;
+}
+
+static int dvb_dummy_tuner_get_frequency(struct dvb_frontend *fe,
+					 u32 *frequency)
+{
+	return 0;
+}
+
+static int dvb_dummy_tuner_get_bandwidth(struct dvb_frontend *fe,
+					 u32 *bandwidth)
+{
+	return 0;
+}
+
+static int dvb_dummy_tuner_get_if_frequency(struct dvb_frontend *fe,
+					    u32 *frequency)
+{
+	return 0;
+}
+
+static int dvb_dummy_tuner_get_status(struct dvb_frontend *fe, u32 *status)
+{
+	return 0;
+}
+
+static const struct dvb_tuner_ops dvb_dummy_tuner_ops = {
+	.release = dvb_dummy_tuner_release,
+	.init = dvb_dummy_tuner_init,
+	.sleep = dvb_dummy_tuner_sleep,
+	.suspend = dvb_dummy_tuner_suspend,
+	.resume = dvb_dummy_tuner_resume,
+	.set_params = dvb_dummy_tuner_set_params,
+	.set_config = dvb_dummy_tuner_set_config,
+	.get_bandwidth = dvb_dummy_tuner_get_bandwidth,
+	.get_frequency = dvb_dummy_tuner_get_frequency,
+	.get_if_frequency = dvb_dummy_tuner_get_if_frequency,
+	.get_status = dvb_dummy_tuner_get_status,
+};
+
+static const struct i2c_device_id dvb_dummy_tuner_i2c_id_table[] = {
+	{"dvb_dummy_tuner", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, dvb_dummy_tuner_i2c_id_table);
+
+static int dvb_dummy_tuner_i2c_probe(struct i2c_client *client,
+				     const struct i2c_device_id *id)
+{
+	int ret = 0;
+	struct dvb_dummy_tuner_config *config = client->dev.platform_data;
+	struct dvb_frontend *fe = config->fe;
+	struct dvb_dummy_tuner_dev *tuner_dev = NULL;
+
+	tuner_dev = kzalloc(sizeof(*tuner_dev), GFP_KERNEL);
+	if (!tuner_dev) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	i2c_set_clientdata(client, tuner_dev);
+	tuner_dev->fe = config->fe;
+
+	memcpy(&fe->ops.tuner_ops,
+	       &dvb_dummy_tuner_ops,
+	       sizeof(struct dvb_tuner_ops));
+
+	fe->tuner_priv = client;
+
+	pr_debug("%s: Successfully probed %s\n", __func__, client->name);
+	return ret;
+
+err:
+	pr_err("%s: failed\n", __func__);
+	return ret;
+}
+
+static int dvb_dummy_tuner_i2c_remove(struct i2c_client *client)
+{
+	struct dvb_dummy_tuner_dev *tuner_dev = i2c_get_clientdata(client);
+	struct dvb_frontend *fe = tuner_dev->fe;
+
+	memset(&fe->ops.tuner_ops, 0, sizeof(struct dvb_tuner_ops));
+	fe->tuner_priv = NULL;
+	kfree(tuner_dev);
+
+	return 0;
+}
+
+static struct i2c_driver dvb_dummy_tuner_i2c_driver = {
+	.driver = {
+		.name = "dvb_dummy_tuner",
+		.suppress_bind_attrs = true,
+	},
+	.probe		= dvb_dummy_tuner_i2c_probe,
+	.remove		= dvb_dummy_tuner_i2c_remove,
+	.id_table	= dvb_dummy_tuner_i2c_id_table,
+};
+module_i2c_driver(dvb_dummy_tuner_i2c_driver);
+
+MODULE_DESCRIPTION("DVB Dummy Tuner");
+MODULE_AUTHOR("Daniel W. S. Almeida");
+MODULE_LICENSE("GPL");
diff --git a/drivers/media/tuners/dvb_dummy_tuner.h b/drivers/media/tuners/dvb_dummy_tuner.h
new file mode 100644
index 000000000000..fde7628258fa
--- /dev/null
+++ b/drivers/media/tuners/dvb_dummy_tuner.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * DVB Dummy Tuner
+ *

Please add details about the driver similar to the .c file.

+ */
+#ifndef __TUNER_DVB_DUMMY_TUNER_H__
+#define __TUNER_DVB_DUMMY_TUNER_H__
+
+#include <media/dvb_frontend.h>
+/**
+ * struct dvb_dummy_tuner_config - configuration parameters for the dummy tuner
+ *
+ * @fe:
+ *	frontend returned by driver
+ */
+struct dvb_dummy_tuner_config {
+	struct dvb_frontend *fe;
+};
+
+#endif /*__TUNER_DVB_DUMMY_TUNER_H__ */



Looks like there is more code to be added to register/unregister

thanks,
-- Shuah






