Hi Sylwester
Thank you for the review again.
On 5 September 2012 22:56, Sylwester Nawrocki
<sylvester.nawro...@gmail.com> wrote:
> Hi Sangwook,
>
> On 09/05/2012 02:28 PM, Sangwook Lee wrote:
[snip]
>> +#include<linux/vmalloc.h>
>
> What do we need this header for ?
Ok, let me delete this.
>
>> +
>> +#include<media/media-entity.h>
>> +#include<media/s5k4ecgx.h>
>> +#include<media/v4l2-ctrls.h>
>> +#include<media/v4l2-device.h>
>> +#include<media/v4l2-mediabus.h>
>> +#include<media/v4l2-subdev.h>
> ...
>> +
>> +static int s5k4ecgx_set_ahb_address(struct v4l2_subdev *sd)
>> +{
>> + int ret;
>> + struct i2c_client *client = v4l2_get_subdevdata(sd);
>> +
>> + /* Set APB peripherals start address */
>> + ret = s5k4ecgx_i2c_write(client, AHB_MSB_ADDR_PTR, GEN_REG_OFFSH);
>> + if (ret)
>> + return ret;
>> + /*
>> + * FIXME: This is copied from s5k6aa, because of no information
>> + * in s5k4ecgx's datasheet.
>> + * sw_reset is activated to put device into idle status
>> + */
>> + ret = s5k4ecgx_i2c_write(client, 0x0010, 0x0001);
>> + if (ret)
>> + return ret;
>> +
>> + /* FIXME: no information available about this register */
>
> Let's drop that comment, we will fix all magic numbers once proper
> documentation is available.
Ok.
>
>> + ret = s5k4ecgx_i2c_write(client, 0x1030, 0x0000);
>> + if (ret)
>> + return ret;
>> + /* Halt ARM CPU */
>> + ret = s5k4ecgx_i2c_write(client, 0x0014, 0x0001);
>> +
>> + return ret;
>
> Just do
>
> return s5k4ecgx_i2c_write(client, 0x0014, 0x0001);
OK, I will fix this.
>> +}
>> +
>> +#define FW_HEAD 6
>> +/* Register address, value are 4, 2 bytes */
>> +#define FW_REG_SIZE 6
>
> FW_REG_SIZE is a bit confusing, maybe we could name this FW_RECORD_SIZE
> or something similar ?
Fair enough
>
>> +/*
>> + * Firmware has the following format:
>> + *<total number of records (4-bytes + 2-bytes padding) N>,< record 0>,
>> + *< record N - 1>,< CRC32-CCITT (4-bytes)>
>> + * where "record" is a 4-byte register address followed by 2-byte
>> + * register value (little endian)
>> + */
>> +static int s5k4ecgx_load_firmware(struct v4l2_subdev *sd)
>> +{
>> + const struct firmware *fw;
>> + int err, i, regs_num;
>> + struct i2c_client *client = v4l2_get_subdevdata(sd);
>> + u16 val;
>> + u32 addr, crc, crc_file, addr_inc = 0;
>> + u8 *fwbuf;
>> +
>> + err = request_firmware(&fw, S5K4ECGX_FIRMWARE, sd->v4l2_dev->dev);
>> + if (err) {
>> + v4l2_err(sd, "Failed to read firmware %s\n",
>> S5K4ECGX_FIRMWARE);
>> + goto fw_out1;
>
> return err;
OK, I will fix this.
>
> ?
>> + }
>> + fwbuf = kmemdup(fw->data, fw->size, GFP_KERNEL);
>
> Why do we need this kmemdup ? Couldn't we just use fw->data ?
OK, Iet me reconsider this.
>
>> + if (!fwbuf) {
>> + err = -ENOMEM;
>> + goto fw_out2;
>> + }
>> + crc_file = *(u32 *)(fwbuf + regs_num * FW_REG_SIZE);
>
> regs_num is uninitialized ?
>
>> + crc = crc32_le(~0, fwbuf, regs_num * FW_REG_SIZE);
>> + if (crc != crc_file) {
>> + v4l2_err(sd, "FW: invalid crc (%#x:%#x)\n", crc, crc_file);
>> + err = -EINVAL;
>> + goto fw_out3;
>> + }
>> + regs_num = *(u32 *)(fwbuf);
>
> I guess this needs to be moved up. I would make it
>
> regs_num = le32_to_cpu(*(u32 *)fw->data);
>
> And perhaps we need a check like:
>
> if (fw->size < regs_num * FW_REG_SIZE)
> return -EINVAL;
> ?
>> + v4l2_dbg(3, debug, sd, "FW: %s size %d register sets %d\n",
>> + S5K4ECGX_FIRMWARE, fw->size, regs_num);
>> + regs_num++; /* Add header */
>> + for (i = 1; i< regs_num; i++) {
>> + addr = *(u32 *)(fwbuf + i * FW_REG_SIZE);
>> + val = *(u16 *)(fwbuf + i * FW_REG_SIZE + 4);
>
> I think you need to access addr and val through le32_to_cpu() as well,
> even though your ARM system might be little-endian by default, this
> driver could possibly be used on machines with different endianness.
>
> Something like this could be more optimal:
>
> const u8 *ptr = fw->data + FW_REG_SIZE;
>
> for (i = 1; i < regs_num; i++) {
> addr = le32_to_cpu(*(u32 *)ptr);
> ptr += 4;
> val = le16_to_cpu(*(u16 *)ptr);
> ptr += FW_REG_SIZE;
>
Thanks for your advice. I will take le32(16)_to_cpu.
>> + if (addr - addr_inc != 2)
>> + err = s5k4ecgx_write(client, addr, val);
>> + else
>> + err = s5k4ecgx_i2c_write(client, REG_CMDBUF0_ADDR,
>> val);
>> + if (err)
>> + goto fw_out3;
>
> nit: break instead of goto ?
Ok, I will fix this.
>
>> + addr_inc = addr;
>> + }
>> +fw_out3:
>> + kfree(fwbuf);
>> +fw_out2:
>> + release_firmware(fw);
>> +fw_out1:
>> +
>> + return err;
>> +}
> ...
>> +static int s5k4ecgx_init_sensor(struct v4l2_subdev *sd)
>> +{
>> + int ret;
>> +
>> + ret = s5k4ecgx_set_ahb_address(sd);
>> + /* The delay is from manufacturer's settings */
>> + msleep(100);
>> +
>> + ret |= s5k4ecgx_load_firmware(sd);
>
> if (!ret)
> ret = s5k4ecgx_load_firmware(sd);
> else
> ?
Ok, I will fix this.
>> +
>> + if (ret)
>> + v4l2_err(sd, "Failed to write initial settings\n");
>> +
>> + return 0;
>
> return ret; ?
> ...
>> +module_i2c_driver(v4l2_i2c_driver);
>> +
>> +MODULE_DESCRIPTION("Samsung S5K4ECGX 5MP SOC camera");
>> +MODULE_AUTHOR("Sangwook Lee<sangwook....@linaro.org>");
>> +MODULE_AUTHOR("Seok-Young Jang<quartz.j...@samsung.com>");
>
> Was there anything really contributed by this person ?
I think I have to give him some credits because I started to work on
the sensor driver which
was originally based on his driver source code. In fact I didn't add
the name, simply
his information was there, so I didn't delete the name, even though
later the driver was getting
more and more from s5k6aa driver.
>
>> +MODULE_LICENSE("GPL");
>> +MODULE_FIRMWARE(S5K4ECGX_FIRMWARE);
>> diff --git a/include/media/s5k4ecgx.h b/include/media/s5k4ecgx.h
>> new file mode 100644
>> index 0000000..fbed5cb
>> --- /dev/null
>> +++ b/include/media/s5k4ecgx.h
>> @@ -0,0 +1,37 @@
>> +/*
>> + * S5K4ECGX image sensor header file
>> + *
>> + * Copyright (C) 2012, Linaro
>> + * Copyright (C) 2011, Samsung Electronics Co., Ltd.
>
> 2011 -> 2012 ?
Ok, I will fix this.
>
> Otherwise looks good. Would be interesting to add capture support
> to this driver later. I've seen it supports JPEG compressed stream,
> also with interleaved preview raw data inside it.
Yes, we can tackle this later.
>
> We have similar problem with S5C73M3 sensor, you have to configure
> two resolutions for JPEG and YUV for a single stream. Here you
> additionally could choose from various preview "sub-stream" pixel
> formats (YCBCR, RGB, etc.).
>
> --
>
> Regards,
> Sylwester
Regards
Sangwook
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