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[v2,09/20] clk: sunxi: Add sun6i MBUS clock support

Message ID 1403016777-15121-10-git-send-email-wens@csie.org
State Superseded, archived
Headers show

Commit Message

Chen-Yu Tsai June 17, 2014, 2:52 p.m. UTC
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
 drivers/clk/sunxi/clk-sunxi.c                     | 44 +++++++++++++++++++++++
 2 files changed, 45 insertions(+)

Comments

Maxime Ripard June 18, 2014, 10:04 a.m. UTC | #1
On Tue, Jun 17, 2014 at 10:52:46PM +0800, Chen-Yu Tsai wrote:
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> ---
>  Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
>  drivers/clk/sunxi/clk-sunxi.c                     | 44 +++++++++++++++++++++++
>  2 files changed, 45 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
> index b9ec668..7b2ba41 100644
> --- a/Documentation/devicetree/bindings/clock/sunxi.txt
> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
> @@ -40,6 +40,7 @@ Required properties:
>  	"allwinner,sun6i-a31-apb2-div-clk" - for the APB2 gates on A31
>  	"allwinner,sun6i-a31-apb2-gates-clk" - for the APB2 gates on A31
>  	"allwinner,sun4i-a10-mod0-clk" - for the module 0 family of clocks
> +	"allwinner,sun6i-a31-mbus-clk" - for the MBUS clocks on A31 / A23
>  	"allwinner,sun7i-a20-out-clk" - for the external output clocks
>  	"allwinner,sun7i-a20-gmac-clk" - for the GMAC clock module on A20/A31
>  	"allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
> diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
> index eca3c6e..a086b5b 100644
> --- a/drivers/clk/sunxi/clk-sunxi.c
> +++ b/drivers/clk/sunxi/clk-sunxi.c
> @@ -307,6 +307,37 @@ static void sun4i_get_mod0_factors(u32 *freq, u32 parent_rate,
>  
>  
>  /**
> + * sun6i_a31_get_mbus_factors() - calculates m factor for MBUS clocks
> + * MBUS rate is calculated as follows
> + * rate = parent_rate / (m + 1);
> + */
> +
> +static void sun6i_a31_get_mbus_factors(u32 *freq, u32 parent_rate,
> +				       u8 *n, u8 *k, u8 *m, u8 *p)
> +{
> +	u8 div;
> +
> +	/* These clocks can only divide, so we will never be able to achieve
> +	 * frequencies higher than the parent frequency */
> +	if (*freq > parent_rate)
> +		*freq = parent_rate;
> +
> +	div = DIV_ROUND_UP(parent_rate, *freq);
> +
> +	if (div > 8)
> +		div = 8;
> +
> +	*freq = parent_rate / div;
> +
> +	/* we were called to round the frequency, we can now return */
> +	if (n == NULL)

s/n/m/ ?

> +		return;
> +
> +	*m = div - 1;
> +}
> +
> +
> +/**
>   * sun7i_a20_get_out_factors() - calculates m, p factors for CLK_OUT_A/B
>   * CLK_OUT rate is calculated as follows
>   * rate = (parent_rate >> p) / (m + 1);
> @@ -447,6 +478,11 @@ static struct clk_factors_config sun4i_mod0_config = {
>  	.pwidth = 2,
>  };
>  
> +static struct clk_factors_config sun6i_a31_mbus_config = {
> +	.mshift = 0,
> +	.mwidth = 3,

Actually, the A31 has an extra N factor.

So this mbus clock looks like it's only about the A23, and not the A31
at all.

Maxime
Chen-Yu Tsai June 23, 2014, 4:44 a.m. UTC | #2
On Wed, Jun 18, 2014 at 6:04 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> On Tue, Jun 17, 2014 at 10:52:46PM +0800, Chen-Yu Tsai wrote:
>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>> ---
>>  Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
>>  drivers/clk/sunxi/clk-sunxi.c                     | 44 +++++++++++++++++++++++
>>  2 files changed, 45 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
>> index b9ec668..7b2ba41 100644
>> --- a/Documentation/devicetree/bindings/clock/sunxi.txt
>> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
>> @@ -40,6 +40,7 @@ Required properties:
>>       "allwinner,sun6i-a31-apb2-div-clk" - for the APB2 gates on A31
>>       "allwinner,sun6i-a31-apb2-gates-clk" - for the APB2 gates on A31
>>       "allwinner,sun4i-a10-mod0-clk" - for the module 0 family of clocks
>> +     "allwinner,sun6i-a31-mbus-clk" - for the MBUS clocks on A31 / A23
>>       "allwinner,sun7i-a20-out-clk" - for the external output clocks
>>       "allwinner,sun7i-a20-gmac-clk" - for the GMAC clock module on A20/A31
>>       "allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
>> diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
>> index eca3c6e..a086b5b 100644
>> --- a/drivers/clk/sunxi/clk-sunxi.c
>> +++ b/drivers/clk/sunxi/clk-sunxi.c
>> @@ -307,6 +307,37 @@ static void sun4i_get_mod0_factors(u32 *freq, u32 parent_rate,
>>
>>
>>  /**
>> + * sun6i_a31_get_mbus_factors() - calculates m factor for MBUS clocks
>> + * MBUS rate is calculated as follows
>> + * rate = parent_rate / (m + 1);
>> + */
>> +
>> +static void sun6i_a31_get_mbus_factors(u32 *freq, u32 parent_rate,
>> +                                    u8 *n, u8 *k, u8 *m, u8 *p)
>> +{
>> +     u8 div;
>> +
>> +     /* These clocks can only divide, so we will never be able to achieve
>> +      * frequencies higher than the parent frequency */
>> +     if (*freq > parent_rate)
>> +             *freq = parent_rate;
>> +
>> +     div = DIV_ROUND_UP(parent_rate, *freq);
>> +
>> +     if (div > 8)
>> +             div = 8;
>> +
>> +     *freq = parent_rate / div;
>> +
>> +     /* we were called to round the frequency, we can now return */
>> +     if (n == NULL)
>
> s/n/m/ ?

The factors clk driver passes all or none pointers.
But I will change this to avoid the confusion.

>> +             return;
>> +
>> +     *m = div - 1;
>> +}
>> +
>> +
>> +/**
>>   * sun7i_a20_get_out_factors() - calculates m, p factors for CLK_OUT_A/B
>>   * CLK_OUT rate is calculated as follows
>>   * rate = (parent_rate >> p) / (m + 1);
>> @@ -447,6 +478,11 @@ static struct clk_factors_config sun4i_mod0_config = {
>>       .pwidth = 2,
>>  };
>>
>> +static struct clk_factors_config sun6i_a31_mbus_config = {
>> +     .mshift = 0,
>> +     .mwidth = 3,
>
> Actually, the A31 has an extra N factor.
>
> So this mbus clock looks like it's only about the A23, and not the A31
> at all.

I checked original sun6i code and sun6i code found in the A23 SDK.
The original code uses the module 0 clock driver for mbus, so yes
there's an extra N factor. The new code in the A23 SDK does not.

Unfortunately I haven't been able to get my Hummingbird A31 up yet,
so I can't poke around to check it.


ChenYu
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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
index b9ec668..7b2ba41 100644
--- a/Documentation/devicetree/bindings/clock/sunxi.txt
+++ b/Documentation/devicetree/bindings/clock/sunxi.txt
@@ -40,6 +40,7 @@  Required properties:
 	"allwinner,sun6i-a31-apb2-div-clk" - for the APB2 gates on A31
 	"allwinner,sun6i-a31-apb2-gates-clk" - for the APB2 gates on A31
 	"allwinner,sun4i-a10-mod0-clk" - for the module 0 family of clocks
+	"allwinner,sun6i-a31-mbus-clk" - for the MBUS clocks on A31 / A23
 	"allwinner,sun7i-a20-out-clk" - for the external output clocks
 	"allwinner,sun7i-a20-gmac-clk" - for the GMAC clock module on A20/A31
 	"allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
index eca3c6e..a086b5b 100644
--- a/drivers/clk/sunxi/clk-sunxi.c
+++ b/drivers/clk/sunxi/clk-sunxi.c
@@ -307,6 +307,37 @@  static void sun4i_get_mod0_factors(u32 *freq, u32 parent_rate,
 
 
 /**
+ * sun6i_a31_get_mbus_factors() - calculates m factor for MBUS clocks
+ * MBUS rate is calculated as follows
+ * rate = parent_rate / (m + 1);
+ */
+
+static void sun6i_a31_get_mbus_factors(u32 *freq, u32 parent_rate,
+				       u8 *n, u8 *k, u8 *m, u8 *p)
+{
+	u8 div;
+
+	/* These clocks can only divide, so we will never be able to achieve
+	 * frequencies higher than the parent frequency */
+	if (*freq > parent_rate)
+		*freq = parent_rate;
+
+	div = DIV_ROUND_UP(parent_rate, *freq);
+
+	if (div > 8)
+		div = 8;
+
+	*freq = parent_rate / div;
+
+	/* we were called to round the frequency, we can now return */
+	if (n == NULL)
+		return;
+
+	*m = div - 1;
+}
+
+
+/**
  * sun7i_a20_get_out_factors() - calculates m, p factors for CLK_OUT_A/B
  * CLK_OUT rate is calculated as follows
  * rate = (parent_rate >> p) / (m + 1);
@@ -447,6 +478,11 @@  static struct clk_factors_config sun4i_mod0_config = {
 	.pwidth = 2,
 };
 
+static struct clk_factors_config sun6i_a31_mbus_config = {
+	.mshift = 0,
+	.mwidth = 3,
+};
+
 /* user manual says "n" but it's really "p" */
 static struct clk_factors_config sun7i_a20_out_config = {
 	.mshift = 8,
@@ -505,6 +541,13 @@  static const struct factors_data sun4i_mod0_data __initconst = {
 	.getter = sun4i_get_mod0_factors,
 };
 
+static const struct factors_data sun6i_a31_mbus_data __initconst = {
+	.enable = 31,
+	.mux = 24,
+	.table = &sun6i_a31_mbus_config,
+	.getter = sun6i_a31_get_mbus_factors,
+};
+
 static const struct factors_data sun7i_a20_out_data __initconst = {
 	.enable = 31,
 	.mux = 24,
@@ -1099,6 +1142,7 @@  static const struct of_device_id clk_factors_match[] __initconst = {
 	{.compatible = "allwinner,sun6i-a31-pll6-clk", .data = &sun6i_a31_pll6_data,},
 	{.compatible = "allwinner,sun4i-a10-apb1-clk", .data = &sun4i_apb1_data,},
 	{.compatible = "allwinner,sun4i-a10-mod0-clk", .data = &sun4i_mod0_data,},
+	{.compatible = "allwinner,sun6i-a31-mbus-clk", .data = &sun6i_a31_mbus_data,},
 	{.compatible = "allwinner,sun7i-a20-out-clk", .data = &sun7i_a20_out_data,},
 	{}
 };