Re: [PATCH 1/4] media: i2c: imx219: Split common registers from mode tables

[Dave Stevenson <dave.stevenson@raspberrypi.com>]

Hi Adam

On Mon, 25 Apr 2022 at 17:51, Adam Ford <aford173@gmail.com> wrote:
>
> On Mon, Apr 25, 2022 at 11:20 AM Dave Stevenson
> <dave.stevenson@raspberrypi.com> wrote:
> >
> > Hi Adam
> >
> > On Tue, 12 Apr 2022 at 14:55, Adam Ford <aford173@gmail.com> wrote:
> > >
> > > There are four modes, and each mode has a table of registers.
> > > Some of the registers are common to all modes, so create new
> > > tables for these common registers to reduce duplicate code.
> > >
> > > Signed-off-by: Adam Ford <aford173@gmail.com>
> > > ---
> > >  drivers/media/i2c/imx219.c | 103 ++++++++++++++-----------------------
> > >  1 file changed, 39 insertions(+), 64 deletions(-)
> > >
> > > diff --git a/drivers/media/i2c/imx219.c b/drivers/media/i2c/imx219.c
> > > index e10af3f74b38..b7cc36b16547 100644
> > > --- a/drivers/media/i2c/imx219.c
> > > +++ b/drivers/media/i2c/imx219.c
> > > @@ -145,19 +145,36 @@ struct imx219_mode {
> > >         struct imx219_reg_list reg_list;
> > >  };
> > >
> > > -/*
> > > - * Register sets lifted off the i2C interface from the Raspberry Pi firmware
> > > - * driver.
> > > - * 3280x2464 = mode 2, 1920x1080 = mode 1, 1640x1232 = mode 4, 640x480 = mode 7.
> > > - */
> > > -static const struct imx219_reg mode_3280x2464_regs[] = {
> > > -       {0x0100, 0x00},
> > > +/* To Access Addresses 3000-5fff, send the following commands */
> > > +static const struct imx219_reg mfg_specific_reg[] = {
> > > +       {0x0100, 0x00}, /* Mode Select */
> > >         {0x30eb, 0x0c},
> > >         {0x30eb, 0x05},
> > >         {0x300a, 0xff},
> > >         {0x300b, 0xff},
> > >         {0x30eb, 0x05},
> > >         {0x30eb, 0x09},
> > > +};
> > > +
> > > +static const struct imx219_reg pll_clk_table[] = {
> > > +
> > > +       {0x0301, 0x05}, /* VTPXCK_DIV */
> > > +       {0x0303, 0x01}, /* VTSYSCK_DIV */
> > > +       {0x0304, 0x03}, /* PREPLLCK_VT_DIV 0x03 = AUTO set */
> > > +       {0x0305, 0x03}, /* PREPLLCK_OP_DIV 0x03 = AUTO set */
> > > +       {0x0306, 0x00}, /* PLL_VT_MPY */
> > > +       {0x0307, 0x39},
> > > +       {0x030b, 0x01}, /* OP_SYS_CLK_DIV */
> > > +       {0x030c, 0x00}, /* PLL_OP_MPY */
> > > +       {0x030d, 0x72},
> > > +};
> >
> > (I've come back to this patch last as my first reading was happy with it)
> > Is there a good reason for making these two tables instead of one with
> > comments as to what the registers are doing?
>
> The pll_clk tables were written after the resolution settings before I
> split them.  I was concerned about having all the common tables in one
> place, because registers would be set in a different order than they
> were originally.  I wasn't sure if the pll clock tables needed to be
> set after the resolution or not.  It seemed possible to me that it
> wouldn't necessarily know how to set the clocks without knowing the
> desired resolution.  I can certainly merge them together and run some
> tests to see if there are regressions.  If there are none, I can keep
> them in a common block.
>
> I can certainly add comments to indicate what's being done.  I had
> thought about it.

More often PLL settings are set before the resolution configuration.

The initialisation sequence for imx219 was provided by Sony, but I
note that the datasheet that Table 37 "Initialization sequence with
XCLR" lists:
- (1) to (3): Refer power up sequence timing diagram
- (4) Set PLL parameters. Basic setting. Set Readout mode. Set MIPI parameters
- (5) Start streaming with 0x0100 (mode_select = 1)
So I really wouldn't be concerned about setting the PLL registers
before the resolution. The PLL configuration is mode independent as
the pixel rate and link frequency are effectively fixed.

  Dave

> >
> > As per my comment on patch 4, one table of registers setting these,
> > the DPHY register, and registers
> >     {0x455e, 0x00},
> >     {0x471e, 0x4b},
> >     {0x4767, 0x0f},
> >     {0x4750, 0x14},
> >     {0x4540, 0x00},
> >     {0x47b4, 0x14},
> >     {0x4713, 0x30},
> >     {0x478b, 0x10},
> >     {0x478f, 0x10},
> >     {0x4793, 0x10},
> >     {0x4797, 0x0e},
> >     {0x479b, 0x0e},
> >     {0x0162, 0x0d},
> >     {0x0163, 0x78},
> > would remove the duplication, reduce the code size, and be slightly
> > more readable.
> >
> >   Dave
> >
> > > +/*
> > > + * Register sets lifted off the i2C interface from the Raspberry Pi firmware
> > > + * driver.
> > > + * 3280x2464 = mode 2, 1920x1080 = mode 1, 1640x1232 = mode 4, 640x480 = mode 7.
> > > + */
> > > +static const struct imx219_reg mode_3280x2464_regs[] = {
> > >         {0x0114, 0x01},
> > >         {0x0128, 0x00},
> > >         {0x012a, 0x18},
> > > @@ -178,15 +195,6 @@ static const struct imx219_reg mode_3280x2464_regs[] = {
> > >         {0x0171, 0x01},
> > >         {0x0174, 0x00},
> > >         {0x0175, 0x00},
> > > -       {0x0301, 0x05},
> > > -       {0x0303, 0x01},
> > > -       {0x0304, 0x03},
> > > -       {0x0305, 0x03},
> > > -       {0x0306, 0x00},
> > > -       {0x0307, 0x39},
> > > -       {0x030b, 0x01},
> > > -       {0x030c, 0x00},
> > > -       {0x030d, 0x72},
> > >         {0x0624, 0x0c},
> > >         {0x0625, 0xd0},
> > >         {0x0626, 0x09},
> > > @@ -208,13 +216,6 @@ static const struct imx219_reg mode_3280x2464_regs[] = {
> > >  };
> > >
> > >  static const struct imx219_reg mode_1920_1080_regs[] = {
> > > -       {0x0100, 0x00},
> > > -       {0x30eb, 0x05},
> > > -       {0x30eb, 0x0c},
> > > -       {0x300a, 0xff},
> > > -       {0x300b, 0xff},
> > > -       {0x30eb, 0x05},
> > > -       {0x30eb, 0x09},
> > >         {0x0114, 0x01},
> > >         {0x0128, 0x00},
> > >         {0x012a, 0x18},
> > > @@ -237,15 +238,6 @@ static const struct imx219_reg mode_1920_1080_regs[] = {
> > >         {0x0171, 0x01},
> > >         {0x0174, 0x00},
> > >         {0x0175, 0x00},
> > > -       {0x0301, 0x05},
> > > -       {0x0303, 0x01},
> > > -       {0x0304, 0x03},
> > > -       {0x0305, 0x03},
> > > -       {0x0306, 0x00},
> > > -       {0x0307, 0x39},
> > > -       {0x030b, 0x01},
> > > -       {0x030c, 0x00},
> > > -       {0x030d, 0x72},
> > >         {0x0624, 0x07},
> > >         {0x0625, 0x80},
> > >         {0x0626, 0x04},
> > > @@ -265,13 +257,6 @@ static const struct imx219_reg mode_1920_1080_regs[] = {
> > >  };
> > >
> > >  static const struct imx219_reg mode_1640_1232_regs[] = {
> > > -       {0x0100, 0x00},
> > > -       {0x30eb, 0x0c},
> > > -       {0x30eb, 0x05},
> > > -       {0x300a, 0xff},
> > > -       {0x300b, 0xff},
> > > -       {0x30eb, 0x05},
> > > -       {0x30eb, 0x09},
> > >         {0x0114, 0x01},
> > >         {0x0128, 0x00},
> > >         {0x012a, 0x18},
> > > @@ -292,15 +277,6 @@ static const struct imx219_reg mode_1640_1232_regs[] = {
> > >         {0x0171, 0x01},
> > >         {0x0174, 0x01},
> > >         {0x0175, 0x01},
> > > -       {0x0301, 0x05},
> > > -       {0x0303, 0x01},
> > > -       {0x0304, 0x03},
> > > -       {0x0305, 0x03},
> > > -       {0x0306, 0x00},
> > > -       {0x0307, 0x39},
> > > -       {0x030b, 0x01},
> > > -       {0x030c, 0x00},
> > > -       {0x030d, 0x72},
> > >         {0x0624, 0x06},
> > >         {0x0625, 0x68},
> > >         {0x0626, 0x04},
> > > @@ -322,13 +298,6 @@ static const struct imx219_reg mode_1640_1232_regs[] = {
> > >  };
> > >
> > >  static const struct imx219_reg mode_640_480_regs[] = {
> > > -       {0x0100, 0x00},
> > > -       {0x30eb, 0x05},
> > > -       {0x30eb, 0x0c},
> > > -       {0x300a, 0xff},
> > > -       {0x300b, 0xff},
> > > -       {0x30eb, 0x05},
> > > -       {0x30eb, 0x09},
> > >         {0x0114, 0x01},
> > >         {0x0128, 0x00},
> > >         {0x012a, 0x18},
> > > @@ -351,15 +320,6 @@ static const struct imx219_reg mode_640_480_regs[] = {
> > >         {0x0171, 0x01},
> > >         {0x0174, 0x03},
> > >         {0x0175, 0x03},
> > > -       {0x0301, 0x05},
> > > -       {0x0303, 0x01},
> > > -       {0x0304, 0x03},
> > > -       {0x0305, 0x03},
> > > -       {0x0306, 0x00},
> > > -       {0x0307, 0x39},
> > > -       {0x030b, 0x01},
> > > -       {0x030c, 0x00},
> > > -       {0x030d, 0x72},
> > >         {0x0624, 0x06},
> > >         {0x0625, 0x68},
> > >         {0x0626, 0x04},
> > > @@ -1041,6 +1001,13 @@ static int imx219_start_streaming(struct imx219 *imx219)
> > >         if (ret < 0)
> > >                 return ret;
> > >
> > > +       /* Send the Manufacturing Header common to all modes */
> > > +       ret = imx219_write_regs(imx219, mfg_specific_reg, ARRAY_SIZE(mfg_specific_reg));
> > > +       if (ret) {
> > > +               dev_err(&client->dev, "%s failed to send mfg header\n", __func__);
> > > +               goto err_rpm_put;
> > > +       }
> > > +
> > >         /* Apply default values of current mode */
> > >         reg_list = &imx219->mode->reg_list;
> > >         ret = imx219_write_regs(imx219, reg_list->regs, reg_list->num_of_regs);
> > > @@ -1056,6 +1023,14 @@ static int imx219_start_streaming(struct imx219 *imx219)
> > >                 goto err_rpm_put;
> > >         }
> > >
> > > +       /* Configure the PLL clocks */
> > > +       ret = imx219_write_regs(imx219, pll_clk_table, ARRAY_SIZE(pll_clk_table));
> > > +       if (ret) {
> > > +               dev_err(&client->dev, "%s failed to sent PLL clocks\n", __func__);
> > > +               goto err_rpm_put;
> > > +       }
> > > +
> > > +
> > >         /* Apply customized values from user */
> > >         ret =  __v4l2_ctrl_handler_setup(imx219->sd.ctrl_handler);
> > >         if (ret)
> > > --
> > > 2.34.1
> > >