This file is responsible for registering the device with the kernel i2c subsystem. v4l2 talks to the saa7113 chip of the device via i2c.
Signed-off-by: Jon Arne Jørgensen <jona...@jonarne.no> --- drivers/media/usb/smi2021/smi2021_i2c.c | 160 ++++++++++++++++++++++++++++++++ 1 file changed, 160 insertions(+) create mode 100644 drivers/media/usb/smi2021/smi2021_i2c.c diff --git a/drivers/media/usb/smi2021/smi2021_i2c.c b/drivers/media/usb/smi2021/smi2021_i2c.c new file mode 100644 index 0000000..5b6f3f5 --- /dev/null +++ b/drivers/media/usb/smi2021/smi2021_i2c.c @@ -0,0 +1,160 @@ +/******************************************************************************* + * smi2021_i2c.c * + * * + * USB Driver for SMI2021 - EasyCAP * + * USB ID 1c88:003c * + * * + * ***************************************************************************** + * + * Copyright 2011-2013 Jon Arne Jørgensen + * <jonjon.arnearne--a.t--gmail.com> + * + * Copyright 2011, 2012 Tony Brown, Michal Demin, Jeffry Johnston + * + * This file is part of SMI2021 + * http://code.google.com/p/easycap-somagic-linux/ + * + * 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, see <http://www.gnu.org/licenses/>. + * + * This driver is heavily influensed by the STK1160 driver. + * Copyright (C) 2012 Ezequiel Garcia + * <elezegarcia--a.t--gmail.com> + * + */ + +#include "smi2021.h" + +/* The device will not return the chip_name on address 0x00. + * But the saa7115 i2c driver needs the chip id to match "f7113" + * if we want to use it, + * so we have to fake the return of this value + */ + +static char chip_id[] = { 'x', 255, 55, 49, 49, 115, 0 }; +static int id_ptr; + +static unsigned int i2c_debug; +module_param(i2c_debug, int, 0644); +MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]"); + +#define dprint_i2c(fmt, args...) \ +do { \ + if (i2c_debug) \ + pr_debug("smi2021[i2c]::%s: " fmt, __func__, ##args); \ +} while (0) + + +static int i2c_xfer(struct i2c_adapter *i2c_adap, + struct i2c_msg msgs[], int num) +{ + struct smi2021_dev *dev = i2c_adap->algo_data; + + switch (num) { + case 2: { /* Read reg */ + if (msgs[0].len != 1 || msgs[1].len != 1) { + dprint_i2c("both messages must be 1 byte\n"); + goto err_out; + + if ((msgs[1].flags & I2C_M_RD) != I2C_M_RD) + dprint_i2c("last message should have rd flag\n"); + goto err_out; + } + + if (msgs[0].buf[0] == 0) { + msgs[1].buf[0] = chip_id[id_ptr]; + if (chip_id[id_ptr] != 0) + id_ptr += 1; + } else { + smi2021_read_reg(dev, msgs[0].addr, msgs[0].buf[0], + msgs[1].buf); + } + break; + } + case 1: { /* Write reg */ + if (msgs[0].len == 0) { + break; + } else if (msgs[0].len != 2) { + dprint_i2c("unsupported len\n"); + goto err_out; + } + if (msgs[0].buf[0] == 0) { + /* We don't handle writing to addr 0x00 */ + break; + } + + smi2021_write_reg(dev, msgs[0].addr, msgs[0].buf[0], + msgs[0].buf[1]); + break; + } + default: { + dprint_i2c("driver can only handle 1 or 2 messages\n"); + goto err_out; + } + } + return num; + +err_out: + return -EOPNOTSUPP; +} + +static u32 functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_SMBUS_EMUL; +} + +static struct i2c_algorithm algo = { + .master_xfer = i2c_xfer, + .functionality = functionality, +}; + +static struct i2c_adapter adap_template = { + .owner = THIS_MODULE, + .name = "smi2021_easycap_dc60", + .algo = &algo, +}; + +static struct i2c_client client_template = { + .name = "smi2021 internal", +}; + +int smi2021_i2c_register(struct smi2021_dev *dev) +{ + int rc; + + id_ptr = 0; + + dev->i2c_adap = adap_template; + dev->i2c_adap.dev.parent = dev->dev; + strcpy(dev->i2c_adap.name, "smi2021"); + dev->i2c_adap.algo_data = dev; + + i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev); + + rc = i2c_add_adapter(&dev->i2c_adap); + if (rc < 0) { + smi2021_err("can't add i2c adapter, errno: %d\n", rc); + return rc; + } + + dev->i2c_client = client_template; + dev->i2c_client.adapter = &dev->i2c_adap; + + return 0; +} + +int smi2021_i2c_unregister(struct smi2021_dev *dev) +{ + i2c_del_adapter(&dev->i2c_adap); + return 0; +} -- 1.8.1.1 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
