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path: root/drivers/media/video/tea6420.c
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Diffstat (limited to 'drivers/media/video/tea6420.c')
-rw-r--r--drivers/media/video/tea6420.c200
1 files changed, 200 insertions, 0 deletions
diff --git a/drivers/media/video/tea6420.c b/drivers/media/video/tea6420.c
new file mode 100644
index 000000000000..bd10710fd909
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+++ b/drivers/media/video/tea6420.c
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+ /*
+ tea6420 - i2c-driver for the tea6420 by SGS Thomson
+
+ Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
+
+ The tea6420 is a bus controlled audio-matrix with 5 stereo inputs,
+ 4 stereo outputs and gain control for each output.
+ It is cascadable, i.e. it can be found at the adresses 0x98
+ and 0x9a on the i2c-bus.
+
+ For detailed informations download the specifications directly
+ from SGS Thomson at http://www.st.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; 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/ioctl.h>
+#include <linux/i2c.h>
+
+#include "tea6420.h"
+
+static int debug = 0; /* insmod parameter */
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "Turn on/off device debugging (default:off).");
+#define dprintk(args...) \
+ do { if (debug) { printk("%s: %s()[%d]: ",__stringify(KBUILD_MODNAME), __FUNCTION__, __LINE__); printk(args); } } while (0)
+
+/* addresses to scan, found only at 0x4c and/or 0x4d (7-Bit) */
+static unsigned short normal_i2c[] = { I2C_TEA6420_1, I2C_TEA6420_2, I2C_CLIENT_END };
+static unsigned short normal_i2c_range[] = { I2C_CLIENT_END };
+
+/* magic definition of all other variables and things */
+I2C_CLIENT_INSMOD;
+
+static struct i2c_driver driver;
+static struct i2c_client client_template;
+
+/* make a connection between the input 'i' and the output 'o'
+ with gain 'g' for the tea6420-client 'client' (note: i = 6 means 'mute') */
+static int tea6420_switch(struct i2c_client *client, int i, int o, int g)
+{
+ u8 byte = 0;
+ int ret;
+
+ dprintk("adr:0x%02x, i:%d, o:%d, g:%d\n", client->addr, i, o, g);
+
+ /* check if the paramters are valid */
+ if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0)
+ return -1;
+
+ byte = ((o - 1) << 5);
+ byte |= (i - 1);
+
+ /* to understand this, have a look at the tea6420-specs (p.5) */
+ switch (g) {
+ case 0:
+ byte |= (3 << 3);
+ break;
+ case 2:
+ byte |= (2 << 3);
+ break;
+ case 4:
+ byte |= (1 << 3);
+ break;
+ case 6:
+ break;
+ }
+
+ ret = i2c_smbus_write_byte(client, byte);
+ if (ret) {
+ dprintk("i2c_smbus_write_byte() failed, ret:%d\n", ret);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+/* this function is called by i2c_probe */
+static int tea6420_detect(struct i2c_adapter *adapter, int address, int kind)
+{
+ struct i2c_client *client;
+ int err = 0, i = 0;
+
+ /* let's see whether this adapter can support what we need */
+ if (0 == i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE)) {
+ return 0;
+ }
+
+ /* allocate memory for client structure */
+ client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
+ if (0 == client) {
+ return -ENOMEM;
+ }
+ memset(client, 0x0, sizeof(struct i2c_client));
+
+ /* fill client structure */
+ memcpy(client, &client_template, sizeof(struct i2c_client));
+ client->addr = address;
+ client->adapter = adapter;
+
+ /* tell the i2c layer a new client has arrived */
+ if (0 != (err = i2c_attach_client(client))) {
+ kfree(client);
+ return err;
+ }
+
+ /* set initial values: set "mute"-input to all outputs at gain 0 */
+ err = 0;
+ for (i = 1; i < 5; i++) {
+ err += tea6420_switch(client, 6, i, 0);
+ }
+ if (err) {
+ dprintk("could not initialize tea6420\n");
+ kfree(client);
+ return -ENODEV;
+ }
+
+ printk("tea6420: detected @ 0x%02x on adapter %s\n", address, &client->adapter->name[0]);
+
+ return 0;
+}
+
+static int attach(struct i2c_adapter *adapter)
+{
+ /* let's see whether this is a know adapter we can attach to */
+ if (adapter->id != I2C_ALGO_SAA7146) {
+ dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter->name, adapter->id);
+ return -ENODEV;
+ }
+
+ return i2c_probe(adapter, &addr_data, &tea6420_detect);
+}
+
+static int detach(struct i2c_client *client)
+{
+ int ret = i2c_detach_client(client);
+ kfree(client);
+ return ret;
+}
+
+static int command(struct i2c_client *client, unsigned int cmd, void *arg)
+{
+ struct tea6420_multiplex *a = (struct tea6420_multiplex *)arg;
+ int result = 0;
+
+ switch (cmd) {
+ case TEA6420_SWITCH:
+ result = tea6420_switch(client, a->in, a->out, a->gain);
+ break;
+ default:
+ return -ENOIOCTLCMD;
+ }
+
+ return result;
+}
+
+static struct i2c_driver driver = {
+ .owner = THIS_MODULE,
+ .name = "tea6420",
+ .id = I2C_DRIVERID_TEA6420,
+ .flags = I2C_DF_NOTIFY,
+ .attach_adapter = attach,
+ .detach_client = detach,
+ .command = command,
+};
+
+static struct i2c_client client_template = {
+ I2C_DEVNAME("tea6420"),
+ .driver = &driver,
+};
+
+static int __init this_module_init(void)
+{
+ return i2c_add_driver(&driver);
+}
+
+static void __exit this_module_exit(void)
+{
+ i2c_del_driver(&driver);
+}
+
+module_init(this_module_init);
+module_exit(this_module_exit);
+
+MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
+MODULE_DESCRIPTION("tea6420 driver");
+MODULE_LICENSE("GPL");