Re: [RFC V1 2/8] smi2021: Add smi2021_main.c

From: Hans Verkuil
Date: Mon Mar 18 2013 - 04:30:56 EST

On Thu March 14 2013 15:06:58 Jon Arne JÃrgensen wrote:
> This is the core of the smi2021 module.
> It will register the module with the kernel, and register the
> usb probe function.
>
> Signed-off-by: Jon Arne JÃrgensen <jonarne@xxxxxxxxxx>
> ---
> drivers/media/usb/smi2021/smi2021_main.c | 339 +++++++++++++++++++++++++++++++
> 1 file changed, 339 insertions(+)
> create mode 100644 drivers/media/usb/smi2021/smi2021_main.c
>
> diff --git a/drivers/media/usb/smi2021/smi2021_main.c b/drivers/media/usb/smi2021/smi2021_main.c
> new file mode 100644
> index 0000000..cc600e7
> --- /dev/null
> +++ b/drivers/media/usb/smi2021/smi2021_main.c
> @@ -0,0 +1,339 @@
> +/*******************************************************************************
> + * smi2021_main.c *
> + * *
> + * USB Driver for SMI2021 - EasyCAP *
> + * USB ID 1c88:003c *
> + * *
> + * *****************************************************************************
> + *
> + * Copyright 2011-2013 Jon Arne JÃrgensen
> + * <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"
> +
> +#define VENDOR_ID 0x1c88
> +
> +static unsigned int imput;
> +module_param(imput, int, 0644);
> +MODULE_PARM_DESC(input, "Set default input");
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Jon Arne JÃrgensen <jonjon.arnearne--a.t--gmail.com>");
> +MODULE_DESCRIPTION("SMI2021 - EasyCap");
> +MODULE_VERSION(SMI2021_DRIVER_VERSION);
> +
> +
> +struct usb_device_id smi2021_usb_device_id_table[] = {
> + { USB_DEVICE(VENDOR_ID, 0x003c) },
> + { USB_DEVICE(VENDOR_ID, 0x003d) },
> + { USB_DEVICE(VENDOR_ID, 0x003e) },
> + { USB_DEVICE(VENDOR_ID, 0x003f) },
> + { }
> +};
> +
> +MODULE_DEVICE_TABLE(usb, smi2021_usb_device_id_table);
> +
> +static unsigned short saa7113_addrs[] = {
> + 0x4a,
> + I2C_CLIENT_END
> +};
> +
> +/******************************************************************************/
> +/* */
> +/* Write to saa7113 */
> +/* */
> +/******************************************************************************/
> +
> +inline int transfer_usb_ctrl(struct smi2021_dev *dev, u8 *data, int len)
> +{
> + return usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0x00),
> + 0x01, USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
> + 0x0b, 0x00,
> + data, len, 1000);
> +}
> +
> +int smi2021_write_reg(struct smi2021_dev *dev, u8 addr, u16 reg, u8 val)
> +{
> + int rc;
> + u8 snd_data[8];
> +
> + memset(snd_data, 0x00, 8);
> +
> + snd_data[SMI2021_CTRL_HEAD] = 0x0b;
> + snd_data[SMI2021_CTRL_ADDR] = addr;
> + snd_data[SMI2021_CTRL_DATA_SIZE] = 0x01;
> +
> + if (addr) {
> + /* This is I2C data for the saa7113 chip */
> + snd_data[SMI2021_CTRL_BM_DATA_TYPE] = 0xc0;
> + snd_data[SMI2021_CTRL_BM_DATA_OFFSET] = 0x01;
> +
> + snd_data[SMI2021_CTRL_I2C_REG] = reg;
> + snd_data[SMI2021_CTRL_I2C_VAL] = val;
> + } else {
> + /* This is register settings for the smi2021 chip */
> + snd_data[SMI2021_CTRL_BM_DATA_OFFSET] = 0x82;
> +
> + snd_data[SMI2021_CTRL_REG_HI] = __cpu_to_be16(reg) >> 8;
> + snd_data[SMI2021_CTRL_REG_LO] = __cpu_to_be16(reg);
> +
> + }
> +

Don't transfer memory from the stack. It always has to be k[mz]alloced memory.

> + rc = transfer_usb_ctrl(dev, snd_data, 8);
> + if (rc < 0) {
> + smi2021_warn("write failed on register 0x%x, errno: %d\n",
> + reg, rc);
> + return rc;
> + }
> +
> + return 0;
> +}
> +
> +int smi2021_read_reg(struct smi2021_dev *dev, u8 addr, u16 reg, u8 *val)
> +{
> + int rc;
> + u8 rcv_data[13];
> + u8 snd_data[8];
> + memset(rcv_data, 0x00, 13);
> + memset(snd_data, 0x00, 8);
> +
> + snd_data[SMI2021_CTRL_HEAD] = 0x0b;
> + snd_data[SMI2021_CTRL_ADDR] = addr;
> + snd_data[SMI2021_CTRL_BM_DATA_TYPE] = 0x84;
> + snd_data[SMI2021_CTRL_DATA_SIZE] = 0x01;
> + snd_data[SMI2021_CTRL_I2C_REG] = reg;
> +
> + *val = 0;
> +

Ditto.

> + rc = transfer_usb_ctrl(dev, snd_data, 8);
> + if (rc < 0) {
> + smi2021_warn(
> + "1st pass failing to read reg 0x%x, usb-errno: %d\n",
> + reg, rc);
> + return rc;
> + }
> +
> + snd_data[SMI2021_CTRL_BM_DATA_TYPE] = 0xa0;
> + rc = transfer_usb_ctrl(dev, snd_data, 8);
> + if (rc < 0) {
> + smi2021_warn(
> + "2nd pass failing to read reg 0x%x, usb-errno: %d\n",
> + reg, rc);
> + return rc;
> + }
> +
> + rc = usb_control_msg(dev->udev,
> + usb_rcvctrlpipe(dev->udev, 0x80), 0x01,
> + USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
> + 0x0b, 0x00, rcv_data, 13, 1000);
> + if (rc < 0) {
> + smi2021_warn("Failed to read reg 0x%x, usb-errno: %d\n",
> + reg, rc);
> + return rc;
> + }
> +
> + *val = rcv_data[SMI2021_CTRL_I2C_RCV_VAL];
> + return 0;
> +}

Regards,

Hans
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