diff mbox

[4/6] clk: sunxi: Make divs clocks specify which output is the parent clock

Message ID 1426785548-5932-5-git-send-email-wens@csie.org (mailing list archive)
State New, archived
Headers show

Commit Message

Chen-Yu Tsai March 19, 2015, 5:19 p.m. UTC
The current sunxi clock driver has the parent of divs clocks as the
last clock output of the clock node. This makes it rather difficult
to add new outputs, such as fixed dividers, which were previously
unknown.

This patch makes the divs clocks data structure specify which output
is the parent clock, and updates all current divs clocks accordingly.

We can then add new outputs after the parent clocks, at least not
breaking backward compatibility with regards to the devicetree bindings.

Also replace kzalloc with kcalloc in sunxi_divs_clk_setup().

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 drivers/clk/sunxi/clk-sunxi.c | 31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

Comments

Maxime Ripard March 21, 2015, 10:53 a.m. UTC | #1
On Fri, Mar 20, 2015 at 01:19:06AM +0800, Chen-Yu Tsai wrote:
> The current sunxi clock driver has the parent of divs clocks as the
> last clock output of the clock node. This makes it rather difficult
> to add new outputs, such as fixed dividers, which were previously
> unknown.
> 
> This patch makes the divs clocks data structure specify which output
> is the parent clock, and updates all current divs clocks accordingly.
> 
> We can then add new outputs after the parent clocks, at least not
> breaking backward compatibility with regards to the devicetree bindings.
> 
> Also replace kzalloc with kcalloc in sunxi_divs_clk_setup().
> 
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> ---
>  drivers/clk/sunxi/clk-sunxi.c | 31 +++++++++++++++++++------------
>  1 file changed, 19 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
> index d92e30371d8a..d28acdde364e 100644
> --- a/drivers/clk/sunxi/clk-sunxi.c
> +++ b/drivers/clk/sunxi/clk-sunxi.c
> @@ -1046,13 +1046,14 @@ static void __init sunxi_gates_clk_setup(struct device_node *node,
>   * sunxi_divs_clk_setup() helper data
>   */
>  
> -#define SUNXI_DIVS_MAX_QTY	2
> +#define SUNXI_DIVS_MAX_QTY	4
>  #define SUNXI_DIVISOR_WIDTH	2
>  
>  struct divs_data {
>  	const struct factors_data *factors; /* data for the factor clock */
> -	int ndivs; /* number of children */
> +	int ndivs; /* number of outputs */
>  	struct {
> +		u8 parent; /* is it the parent? (only one please) */

I really don't get what this "parent" is about. Is it a clock passed
through to the users.

Do we have even have users for these?

Thanks,
Maxime
Chen-Yu Tsai March 23, 2015, 7:07 a.m. UTC | #2
On Sat, Mar 21, 2015 at 6:53 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> On Fri, Mar 20, 2015 at 01:19:06AM +0800, Chen-Yu Tsai wrote:
>> The current sunxi clock driver has the parent of divs clocks as the
>> last clock output of the clock node. This makes it rather difficult
>> to add new outputs, such as fixed dividers, which were previously
>> unknown.
>>
>> This patch makes the divs clocks data structure specify which output
>> is the parent clock, and updates all current divs clocks accordingly.
>>
>> We can then add new outputs after the parent clocks, at least not
>> breaking backward compatibility with regards to the devicetree bindings.
>>
>> Also replace kzalloc with kcalloc in sunxi_divs_clk_setup().
>>
>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>> ---
>>  drivers/clk/sunxi/clk-sunxi.c | 31 +++++++++++++++++++------------
>>  1 file changed, 19 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
>> index d92e30371d8a..d28acdde364e 100644
>> --- a/drivers/clk/sunxi/clk-sunxi.c
>> +++ b/drivers/clk/sunxi/clk-sunxi.c
>> @@ -1046,13 +1046,14 @@ static void __init sunxi_gates_clk_setup(struct device_node *node,
>>   * sunxi_divs_clk_setup() helper data
>>   */
>>
>> -#define SUNXI_DIVS_MAX_QTY   2
>> +#define SUNXI_DIVS_MAX_QTY   4
>>  #define SUNXI_DIVISOR_WIDTH  2
>>
>>  struct divs_data {
>>       const struct factors_data *factors; /* data for the factor clock */
>> -     int ndivs; /* number of children */
>> +     int ndivs; /* number of outputs */
>>       struct {
>> +             u8 parent; /* is it the parent? (only one please) */
>
> I really don't get what this "parent" is about. Is it a clock passed
> through to the users.

It is the PLL itself (the rate doubled one if you will),
which then has the separate divided outputs. Or:

    sun6i: PLL6x2 -> PLL6
    sun7i: PLL6 -> {PLL6 SATA, PLL6 other}

> Do we have even have users for these?

The mbus clocks use the doubled PLL6 as one of it's inputs.
There are no users of the parent PLL5 clock. This can be seen
in the .dtsi files, where PLL6 has a clock-output-name for
itself, while PLL5 does not. However the clock driver has
always exported the parent clock as the last clock for the
node.

ChenYu
diff mbox

Patch

diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
index d92e30371d8a..d28acdde364e 100644
--- a/drivers/clk/sunxi/clk-sunxi.c
+++ b/drivers/clk/sunxi/clk-sunxi.c
@@ -1046,13 +1046,14 @@  static void __init sunxi_gates_clk_setup(struct device_node *node,
  * sunxi_divs_clk_setup() helper data
  */
 
-#define SUNXI_DIVS_MAX_QTY	2
+#define SUNXI_DIVS_MAX_QTY	4
 #define SUNXI_DIVISOR_WIDTH	2
 
 struct divs_data {
 	const struct factors_data *factors; /* data for the factor clock */
-	int ndivs; /* number of children */
+	int ndivs; /* number of outputs */
 	struct {
+		u8 parent; /* is it the parent? (only one please) */
 		u8 fixed; /* is it a fixed divisor? if not... */
 		struct clk_div_table *table; /* is it a table based divisor? */
 		u8 shift; /* otherwise it's a normal divisor with this shift */
@@ -1075,23 +1076,26 @@  static const struct divs_data pll5_divs_data __initconst = {
 	.div = {
 		{ .shift = 0, .pow = 0, }, /* M, DDR */
 		{ .shift = 16, .pow = 1, }, /* P, other */
+		/* No output for the parent */
 	}
 };
 
 static const struct divs_data pll6_divs_data __initconst = {
 	.factors = &sun4i_pll6_data,
-	.ndivs = 2,
+	.ndivs = 3,
 	.div = {
 		{ .shift = 0, .table = pll6_sata_tbl, .gate = 14 }, /* M, SATA */
 		{ .fixed = 2 }, /* P, other */
+		{ .parent = 1 }, /* parent, 2x */
 	}
 };
 
 static const struct divs_data sun6i_a31_pll6_divs_data __initconst = {
 	.factors = &sun6i_a31_pll6_data,
-	.ndivs = 1,
+	.ndivs = 2,
 	.div = {
 		{ .fixed = 2 }, /* normal output */
+		{ .parent = 1 }, /* parent, 2x */
 	}
 };
 
@@ -1122,6 +1126,10 @@  static void __init sunxi_divs_clk_setup(struct device_node *node,
 	int ndivs = SUNXI_DIVS_MAX_QTY, i = 0;
 	int flags, clkflags;
 
+	/* if number of children known, use it */
+	if (data->ndivs)
+		ndivs = data->ndivs;
+
 	/* Set up factor clock that we will be dividing */
 	pclk = sunxi_factors_clk_setup(node, data->factors);
 	parent = __clk_get_name(pclk);
@@ -1132,7 +1140,7 @@  static void __init sunxi_divs_clk_setup(struct device_node *node,
 	if (!clk_data)
 		return;
 
-	clks = kzalloc((SUNXI_DIVS_MAX_QTY+1) * sizeof(*clks), GFP_KERNEL);
+	clks = kcalloc(ndivs, sizeof(*clks), GFP_KERNEL);
 	if (!clks)
 		goto free_clkdata;
 
@@ -1142,15 +1150,17 @@  static void __init sunxi_divs_clk_setup(struct device_node *node,
 	 * our RAM clock! */
 	clkflags = !strcmp("pll5", parent) ? 0 : CLK_SET_RATE_PARENT;
 
-	/* if number of children known, use it */
-	if (data->ndivs)
-		ndivs = data->ndivs;
-
 	for (i = 0; i < ndivs; i++) {
 		if (of_property_read_string_index(node, "clock-output-names",
 						  i, &clk_name) != 0)
 			break;
 
+		/* If this is the parent, just update clks and skip */
+		if (data->div[i].parent) {
+			clk_data->clks[i] = pclk;
+			continue;
+		}
+
 		gate_hw = NULL;
 		rate_hw = NULL;
 		rate_ops = NULL;
@@ -1209,9 +1219,6 @@  static void __init sunxi_divs_clk_setup(struct device_node *node,
 		clk_register_clkdev(clks[i], clk_name, NULL);
 	}
 
-	/* The last clock available on the getter is the parent */
-	clks[i++] = pclk;
-
 	/* Adjust to the real max */
 	clk_data->clk_num = i;