Hi Sakari,
On Wednesday 27 July 2011 12:13:05 Sakari Ailus wrote:
> Hi Laurent,
>
> Thanks for the patch. I have a few comments below.
Thanks for the review. Please see my answers to your comments below. Javier,
there's one question for you as well.
> On Wed, Jul 27, 2011 at 11:13:01AM +0200, Laurent Pinchart wrote:
[snip]
> > +static struct mt9p031 *to_mt9p031(struct v4l2_subdev *sd)
> > +{
> > + return container_of(sd, struct mt9p031, subdev);
> > +}
> > +
> > +static int mt9p031_read(struct i2c_client *client, u8 reg)
> > +{
> > + s32 data = i2c_smbus_read_word_data(client, reg);
> > + return data < 0 ? data : swab16(data);
>
> Why swab16, and not e.g. be16_to_cpu?
No reason. I'll fix that.
> > +}
> > +
> > +static int mt9p031_write(struct i2c_client *client, u8 reg, u16 data)
> > +{
> > + return i2c_smbus_write_word_data(client, reg, swab16(data));
>
> Same here.
>
> > +}
[snip]
> > +/*
> > + * This static table uses ext_freq and vdd_io values to select suitable
> > + * PLL dividers m, n and p1 which have been calculated as specifiec in
> > p36 + * of Aptina's mt9p031 datasheet. New values should be added here.
> > + */
> > +static const struct mt9p031_pll_divs mt9p031_divs[] = {
> > + /* ext_freq target_freq m n p1 */
> > + {21000000, 48000000, 26, 2, 6}
>
> Can the divisors be calculated dynamically?
>
> The external clock frequency, target_freq (pixel clock, I assume!) are
> typically highly board dependent.
Probably. That's on my TODO list.
> > +};
> > +
> > +static int mt9p031_pll_get_divs(struct mt9p031 *mt9p031)
> > +{
> > + struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
> > + int i;
> > +
> > + for (i = 0; i < ARRAY_SIZE(mt9p031_divs); i++) {
> > + if (mt9p031_divs[i].ext_freq == mt9p031->pdata->ext_freq &&
> > + mt9p031_divs[i].target_freq == mt9p031->pdata->target_freq) {
> > + mt9p031->ext_freq = mt9p031_divs[i].ext_freq;
> > + mt9p031->m = mt9p031_divs[i].m;
> > + mt9p031->n = mt9p031_divs[i].n;
> > + mt9p031->p1 = mt9p031_divs[i].p1;
>
> What about a pointer to the array instead of copying the values?
Sounds good to me.
> > + return 0;
> > + }
> > + }
> > +
> > + dev_err(&client->dev, "Couldn't find PLL dividers for ext_freq = %d, "
> > + "target_freq = %d\n", mt9p031->pdata->ext_freq,
> > + mt9p031->pdata->target_freq);
> > + return -EINVAL;
> > +}
> > +
> > +static int mt9p031_pll_enable(struct mt9p031 *mt9p031)
> > +{
> > + struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
> > + int ret;
> > +
> > + ret = mt9p031_write(client, MT9P031_PLL_CONTROL,
> > + MT9P031_PLL_CONTROL_PWRON);
> > + if (ret < 0)
> > + return ret;
> > +
> > + ret = mt9p031_write(client, MT9P031_PLL_CONFIG_1,
> > + (mt9p031->m << 8) | (mt9p031->n - 1));
> > + if (ret < 0)
> > + return ret;
> > +
> > + ret = mt9p031_write(client, MT9P031_PLL_CONFIG_2, mt9p031->p1 - 1);
> > + if (ret < 0)
> > + return ret;
> > +
> > + mdelay(1);
>
> mdelay() is a busyloop. Either msleep(), if the timing isn't critical, and
> if it is, then usleep_range().
Timing isn't critical, but that's a stream-on delay, so I'll use
usleep_range().
> > + ret = mt9p031_write(client, MT9P031_PLL_CONTROL,
> > + MT9P031_PLL_CONTROL_PWRON |
> > + MT9P031_PLL_CONTROL_USEPLL);
> > + mdelay(1);
Javier, is this second mdelay() needed ?
> > + return ret;
> > +}
> > +
> > +static inline int mt9p031_pll_disable(struct mt9p031 *mt9p031)
> > +{
> > + struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
> > +
> > + return mt9p031_write(client, MT9P031_PLL_CONTROL,
> > + MT9P031_PLL_CONTROL_PWROFF);
> > +}
> > +
> > +static int mt9p031_power_on(struct mt9p031 *mt9p031)
> > +{
> > + /* Ensure RESET_BAR is low */
> > + if (mt9p031->pdata->reset) {
> > + mt9p031->pdata->reset(&mt9p031->subdev, 1);
> > + msleep(1);
>
> msleep(1) may take considerably longer than 1 ms, depending on the system
> clock. You might want to use usleep_range() here.
Good point.
> > + }
> > +
> > + /* Emable clock */
> > + if (mt9p031->pdata->set_xclk)
> > + mt9p031->pdata->set_xclk(&mt9p031->subdev,
> > + mt9p031->pdata->ext_freq);
> > +
> > + /* Now RESET_BAR must be high */
> > + if (mt9p031->pdata->reset) {
> > + mt9p031->pdata->reset(&mt9p031->subdev, 0);
> > + msleep(1);
> > + }
> > +
> > + return 0;
> > +}
[snip]
> > +static int mt9p031_set_params(struct mt9p031 *mt9p031)
> > +{
> > + struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
> > + struct v4l2_mbus_framefmt *format = &mt9p031->format;
> > + const struct v4l2_rect *crop = &mt9p031->crop;
> > + unsigned int hblank;
> > + unsigned int vblank;
> > + unsigned int xskip;
> > + unsigned int yskip;
> > + unsigned int xbin;
> > + unsigned int ybin;
> > + int ret;
> > +
> > + /* Windows position and size.
> > + *
> > + * TODO: Make sure the start coordinates and window size match the
> > + * skipping, binning and mirroring (see description of registers 2 and
> > 4 + * in table 13, and Binning section on page 41).
> > + */
> > + ret = mt9p031_write(client, MT9P031_COLUMN_START, crop->left);
> > + if (ret < 0)
> > + return ret;
> > + ret = mt9p031_write(client, MT9P031_ROW_START, crop->top);
> > + if (ret < 0)
> > + return ret;
> > + ret = mt9p031_write(client, MT9P031_WINDOW_WIDTH, crop->width - 1);
> > + if (ret < 0)
> > + return ret;
> > + ret = mt9p031_write(client, MT9P031_WINDOW_HEIGHT, crop->height - 1);
> > + if (ret < 0)
> > + return ret;
> > +
> > + /* Row and column binning and skipping. Use the maximum binning value
> > + * compatible with the skipping settings.
> > + */
> > + xskip = DIV_ROUND_CLOSEST(crop->width, format->width);
> > + yskip = DIV_ROUND_CLOSEST(crop->height, format->height);
> > + xbin = 1 << (ffs(xskip) - 1);
> > + ybin = 1 << (ffs(yskip) - 1);
> > +
> > + ret = mt9p031_write(client, MT9P031_COLUMN_ADDRESS_MODE,
> > + ((xbin - 1) << 4) | (xskip - 1));
> > + if (ret < 0)
> > + return ret;
> > + ret = mt9p031_write(client, MT9P031_ROW_ADDRESS_MODE,
> > + ((ybin - 1) << 4) | (yskip - 1));
> > + if (ret < 0)
> > + return ret;
> > +
> > + /* Blanking - use minimum value for horizontal blanking and default
> > + * value for vertical blanking.
> > + */
> > + hblank = 346 * ybin + 64 + (80 >> max_t(unsigned int, xbin, 3));
>
> Where do all these numbers come from? :-)
Directly from the datasheet :-) See table 8.
> I saw very nice register definitions and value ranges in the beginning of
> the patch.
>
> > + vblank = MT9P031_VERTICAL_BLANK_DEF;
> > +
> > + ret = mt9p031_write(client, MT9P031_HORIZONTAL_BLANK, hblank);
> > + if (ret < 0)
> > + return ret;
> > + ret = mt9p031_write(client, MT9P031_VERTICAL_BLANK, vblank);
> > + if (ret < 0)
> > + return ret;
> > +
> > + return ret;
> > +}
[snip]
> > +static int mt9p031_s_ctrl(struct v4l2_ctrl *ctrl)
> > +{
> > + struct mt9p031 *mt9p031 =
> > + container_of(ctrl->handler, struct mt9p031, ctrls);
> > + struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
> > + u16 data;
> > + int ret;
> > +
> > + switch (ctrl->id) {
> > + case V4L2_CID_EXPOSURE:
> > + ret = mt9p031_write(client, MT9P031_SHUTTER_WIDTH_UPPER,
> > + (ctrl->val >> 16) & 0xffff);
> > + if (ret < 0)
> > + return ret;
> > +
> > + return mt9p031_write(client, MT9P031_SHUTTER_WIDTH_LOWER,
> > + ctrl->val & 0xffff);
> > +
> > + case V4L2_CID_GAIN:
> > + /* Gain is controlled by 2 analog stages and a digital stage.
>
> Just a general question: shouldn't there be another control for digital (or
> analog) range? Which to change in what point of time is somewhat a policy
> decision. Sometimes the user would also want to know that (s)he is using
> digital gain.
The could indeed be useful. Green/blue/red gain controls could be useful as
well. We need to standardize them :-)
> > + * Valid values for the 3 stages are
> > + *
> > + * Stage Min Max Step
> > + * ------------------------------------------
> > + * First analog stage x1 x2 1
> > + * Second analog stage x1 x4 0.125
> > + * Digital stage x1 x16 0.125
> > + *
> > + * To minimize noise, the gain stages should be used in the
> > + * second analog stage, first analog stage, digital stage order.
> > + * Gain from a previous stage should be pushed to its maximum
> > + * value before the next stage is used.
> > + */
> > + if (ctrl->val <= 32) {
> > + data = ctrl->val;
> > + } else if (ctrl->val <= 64) {
> > + ctrl->val &= ~1;
> > + data = (1 << 6) | (ctrl->val >> 1);
> > + } else {
> > + ctrl->val &= ~7;
> > + data = ((ctrl->val - 64) << 5) | (1 << 6) | 32;
> > + }
> > +
> > + return mt9p031_write(client, MT9P031_GLOBAL_GAIN, data);
> > +
> > + case V4L2_CID_HFLIP:
> > + if (ctrl->val)
> > + return mt9p031_set_mode2(mt9p031,
> > + 0, MT9P031_READ_MODE_2_COL_MIR);
> > + else
> > + return mt9p031_set_mode2(mt9p031,
> > + MT9P031_READ_MODE_2_COL_MIR, 0);
> > +
> > + case V4L2_CID_VFLIP:
> > + if (ctrl->val)
> > + return mt9p031_set_mode2(mt9p031,
> > + 0, MT9P031_READ_MODE_2_ROW_MIR);
> > + else
> > + return mt9p031_set_mode2(mt9p031,
> > + MT9P031_READ_MODE_2_ROW_MIR, 0);
> > +
> > + case V4L2_CID_TEST_PATTERN:
> > + if (!ctrl->val) {
> > + ret = mt9p031_set_mode2(mt9p031,
> > + 0, MT9P031_READ_MODE_2_ROW_BLC);
> > + if (ret < 0)
> > + return ret;
> > +
> > + return mt9p031_write(client, MT9P031_TEST_PATTERN,
> > + MT9P031_TEST_PATTERN_DISABLE);
> > + }
> > +
> > + ret = mt9p031_write(client, MT9P031_TEST_PATTERN_GREEN, 0x05a0);
> > + if (ret < 0)
> > + return ret;
> > + ret = mt9p031_write(client, MT9P031_TEST_PATTERN_RED, 0x0a50);
> > + if (ret < 0)
> > + return ret;
> > + ret = mt9p031_write(client, MT9P031_TEST_PATTERN_BLUE, 0x0aa0);
> > + if (ret < 0)
> > + return ret;
> > +
> > + ret = mt9p031_set_mode2(mt9p031, MT9P031_READ_MODE_2_ROW_BLC,
> > + 0);
> > + if (ret < 0)
> > + return ret;
> > + ret = mt9p031_write(client, MT9P031_ROW_BLACK_DEF_OFFSET, 0);
> > + if (ret < 0)
> > + return ret;
> > +
> > + return mt9p031_write(client, MT9P031_TEST_PATTERN,
> > + ((ctrl->val - 1) << MT9P031_TEST_PATTERN_SHIFT)
> > + | MT9P031_TEST_PATTERN_ENABLE);
> > + }
> > + return 0;
> > +}
> > +
> > +static struct v4l2_ctrl_ops mt9p031_ctrl_ops = {
> > + .s_ctrl = mt9p031_s_ctrl,
> > +};
> > +
> > +static const char * const mt9p031_test_pattern_menu[] = {
> > + "Disabled",
> > + "Color Field",
> > + "Horizontal Gradient",
> > + "Vertical Gradient",
> > + "Diagonal Gradient",
> > + "Classic Test Pattern",
> > + "Walking 1s",
> > + "Monochrome Horizontal Bars",
> > + "Monochrome Vertical Bars",
> > + "Vertical Color Bars",
> > +};
> > +
> > +static const struct v4l2_ctrl_config mt9p031_ctrls[] = {
> > + {
> > + .ops = &mt9p031_ctrl_ops,
> > + .id = V4L2_CID_TEST_PATTERN,
> > + .type = V4L2_CTRL_TYPE_MENU,
> > + .name = "Test Pattern",
> > + .min = 0,
> > + .max = 9,
>
> I wonder if ARRAY_SIZE(mt9p031_test_pattern_menu) would return something
> sensible.
I can try :-) (minus one though).
> > + .step = 0,
> > + .def = 0,
> > + .flags = 0,
> > + .menu_skip_mask = 0,
> > + .qmenu = mt9p031_test_pattern_menu,
> > + }
> > +};
[snip]
> > +static int mt9p031_probe(struct i2c_client *client,
> > + const struct i2c_device_id *did)
> > +{
> > + struct mt9p031_platform_data *pdata = client->dev.platform_data;
>
> You might want to check pdata isn't NULL.
Good point again well.
> > + struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
> > + struct mt9p031 *mt9p031;
> > + unsigned int i;
> > + int ret;
> > +
> > + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
> > + dev_warn(&adapter->dev,
> > + "I2C-Adapter doesn't support I2C_FUNC_SMBUS_WORD\n");
> > + return -EIO;
> > + }
> > +
> > + mt9p031 = kzalloc(sizeof(*mt9p031), GFP_KERNEL);
> > + if (mt9p031 == NULL)
> > + return -ENOMEM;
> > +
> > + mt9p031->pdata = pdata;
> > + mt9p031->output_control = MT9P031_OUTPUT_CONTROL_DEF;
> > + mt9p031->mode2 = MT9P031_READ_MODE_2_ROW_BLC;
> > +
> > + v4l2_ctrl_handler_init(&mt9p031->ctrls, ARRAY_SIZE(mt9p031_ctrls) + 4);
> > +
> > + v4l2_ctrl_new_std(&mt9p031->ctrls, &mt9p031_ctrl_ops,
> > + V4L2_CID_EXPOSURE, MT9P031_SHUTTER_WIDTH_MIN,
> > + MT9P031_SHUTTER_WIDTH_MAX, 1,
> > + MT9P031_SHUTTER_WIDTH_DEF);
> > + v4l2_ctrl_new_std(&mt9p031->ctrls, &mt9p031_ctrl_ops,
> > + V4L2_CID_GAIN, MT9P031_GLOBAL_GAIN_MIN,
> > + MT9P031_GLOBAL_GAIN_MAX, 1, MT9P031_GLOBAL_GAIN_DEF);
> > + v4l2_ctrl_new_std(&mt9p031->ctrls, &mt9p031_ctrl_ops,
> > + V4L2_CID_HFLIP, 0, 1, 1, 0);
> > + v4l2_ctrl_new_std(&mt9p031->ctrls, &mt9p031_ctrl_ops,
> > + V4L2_CID_VFLIP, 0, 1, 1, 0);
> > +
> > + for (i = 0; i < ARRAY_SIZE(mt9p031_ctrls); ++i)
> > + v4l2_ctrl_new_custom(&mt9p031->ctrls, &mt9p031_ctrls[i], NULL);
> > +
> > + mt9p031->subdev.ctrl_handler = &mt9p031->ctrls;
> > +
> > + if (mt9p031->ctrls.error)
> > + printk(KERN_INFO "%s: control initialization error %d\n",
> > + __func__, mt9p031->ctrls.error);
> > +
> > + mutex_init(&mt9p031->power_lock);
> > + v4l2_i2c_subdev_init(&mt9p031->subdev, client, &mt9p031_subdev_ops);
> > + mt9p031->subdev.internal_ops = &mt9p031_subdev_internal_ops;
> > +
> > + mt9p031->pad.flags = MEDIA_PAD_FL_SOURCE;
> > + ret = media_entity_init(&mt9p031->subdev.entity, 1, &mt9p031->pad, 0);
> > + if (ret < 0)
> > + goto done;
> > +
> > + mt9p031->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > +
> > + mt9p031->crop.width = MT9P031_WINDOW_WIDTH_DEF;
> > + mt9p031->crop.height = MT9P031_WINDOW_HEIGHT_DEF;
> > + mt9p031->crop.left = MT9P031_COLUMN_START_DEF;
> > + mt9p031->crop.top = MT9P031_ROW_START_DEF;
> > +
> > + if (mt9p031->pdata->version == MT9P031_MONOCHROME_VERSION)
> > + mt9p031->format.code = V4L2_MBUS_FMT_Y12_1X12;
> > + else
> > + mt9p031->format.code = V4L2_MBUS_FMT_SGRBG12_1X12;
> > +
> > + mt9p031->format.width = MT9P031_WINDOW_WIDTH_DEF;
> > + mt9p031->format.height = MT9P031_WINDOW_HEIGHT_DEF;
> > + mt9p031->format.field = V4L2_FIELD_NONE;
> > + mt9p031->format.colorspace = V4L2_COLORSPACE_SRGB;
> > +
> > + ret = mt9p031_pll_get_divs(mt9p031);
> > +
> > +done:
> > + if (ret < 0)
> > + kfree(mt9p031);
> > +
> > + return ret;
> > +}
--
Regards,
Laurent Pinchart
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