Re: [PATCH net-next v7 8/8] mfd: zl3073x: Register DPLL sub-device during init

On Wed, 07 May 2025, Andy Shevchenko wrote:

On Wed, May 07, 2025 at 03:56:37PM +0200, Ivan Vecera wrote:

quoted

On 07. 05. 25 3:41 odp., Andy Shevchenko wrote:

quoted

On Wed, May 7, 2025 at 3:45 PM Ivan Vecera [off-list ref] wrote:

...

quoted

quoted

quoted

+static const struct zl3073x_pdata zl3073x_pdata[ZL3073X_MAX_CHANNELS] = {
+       { .channel = 0, },
+       { .channel = 1, },
+       { .channel = 2, },
+       { .channel = 3, },
+       { .channel = 4, },
+};

quoted

+static const struct mfd_cell zl3073x_devs[] = {
+       ZL3073X_CELL("zl3073x-dpll", 0),
+       ZL3073X_CELL("zl3073x-dpll", 1),
+       ZL3073X_CELL("zl3073x-dpll", 2),
+       ZL3073X_CELL("zl3073x-dpll", 3),
+       ZL3073X_CELL("zl3073x-dpll", 4),
+};

quoted

+#define ZL3073X_MAX_CHANNELS   5

Btw, wouldn't be better to keep the above lists synchronised like

1. Make ZL3073X_CELL() to use indexed variant

[idx] = ...

2. Define the channel numbers

and use them in both data structures.

...

WDYM?

quoted

OTOH, I'm not sure why we even need this. If this is going to be
sequential, can't we make a core to decide which cell will be given
which id?

Just a note that after introduction of PHC sub-driver the array will look
like:
static const struct mfd_cell zl3073x_devs[] = {
       ZL3073X_CELL("zl3073x-dpll", 0),  // DPLL sub-dev for chan 0
       ZL3073X_CELL("zl3073x-phc", 0),   // PHC sub-dev for chan 0
       ZL3073X_CELL("zl3073x-dpll", 1),  // ...
       ZL3073X_CELL("zl3073x-phc", 1),
       ZL3073X_CELL("zl3073x-dpll", 2),
       ZL3073X_CELL("zl3073x-phc", 2),
       ZL3073X_CELL("zl3073x-dpll", 3),
       ZL3073X_CELL("zl3073x-phc", 3),
       ZL3073X_CELL("zl3073x-dpll", 4),
       ZL3073X_CELL("zl3073x-phc", 4),   // PHC sub-dev for chan 4
};

Ah, this is very important piece. Then I mean only this kind of change

enum {
	// this or whatever meaningful names
	..._CH_0	0
	..._CH_1	1
	...
};

static const struct zl3073x_pdata zl3073x_pdata[ZL3073X_MAX_CHANNELS] = {
       { .channel = ..._CH_0, },
       ...
};

static const struct mfd_cell zl3073x_devs[] = {
       ZL3073X_CELL("zl3073x-dpll", ..._CH_0),
       ZL3073X_CELL("zl3073x-phc", ..._CH_0),
       ...
};

This is getting hectic.  All for a sequential enumeration.  Seeing as
there are no other differentiations, why not use IDA in the child
instead?

-- 
Lee Jones [李琼斯]