diff mbox series

[v5,1/8] clk: tegra: Add PLLP_UD and PLLMB_UD for Tegra210

Message ID 20200310152003.2945170-2-thierry.reding@gmail.com (mailing list archive)
State Superseded, archived
Headers show
Series Add EMC scaling support for Tegra210 | expand

Commit Message

Thierry Reding March 10, 2020, 3:19 p.m. UTC 
From: Joseph Lo <josephl@nvidia.com>

Introduce the low jitter path of PLLP and PLLMB which can be used as EMC
clock source.

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/clk/tegra/clk-tegra210.c         | 11 +++++++++++
 include/dt-bindings/clock/tegra210-car.h |  4 ++--
 2 files changed, 13 insertions(+), 2 deletions(-)

Comments

Dmitry Osipenko March 10, 2020, 4:19 p.m. UTC | #1 
10.03.2020 18:19, Thierry Reding пишет:
> From: Joseph Lo <josephl@nvidia.com>
> 
> Introduce the low jitter path of PLLP and PLLMB which can be used as EMC
> clock source.
> 
> Signed-off-by: Joseph Lo <josephl@nvidia.com>
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  drivers/clk/tegra/clk-tegra210.c         | 11 +++++++++++
>  include/dt-bindings/clock/tegra210-car.h |  4 ++--
>  2 files changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c
> index 45d54ead30bc..f99647b4a71f 100644
> --- a/drivers/clk/tegra/clk-tegra210.c
> +++ b/drivers/clk/tegra/clk-tegra210.c
> @@ -3161,6 +3161,17 @@ static void __init tegra210_pll_init(void __iomem *clk_base,
>  	clk_register_clkdev(clk, "pll_m_ud", NULL);
>  	clks[TEGRA210_CLK_PLL_M_UD] = clk;
>  
> +	/* PLLMB_UD */
> +	clk = clk_register_fixed_factor(NULL, "pll_mb_ud", "pll_mb",
> +					CLK_SET_RATE_PARENT, 1, 1);
> +	clk_register_clkdev(clk, "pll_mb_ud", NULL);
> +	clks[TEGRA210_CLK_PLL_MB_UD] = clk;
> +
> +	/* PLLP_UD */
> +	clk = clk_register_fixed_factor(NULL, "pll_p_ud", "pll_p",
> +					0, 1, 1);
> +	clks[TEGRA210_CLK_PLL_P_UD] = clk;

Isn't it possible to auto-enable the low-jitter bit when necessary
during of the rate-change based on a given clock-rate?
Thierry Reding March 10, 2020, 5:05 p.m. UTC | #2 
On Tue, Mar 10, 2020 at 07:19:59PM +0300, Dmitry Osipenko wrote:
> 10.03.2020 18:19, Thierry Reding пишет:
> > From: Joseph Lo <josephl@nvidia.com>
> > 
> > Introduce the low jitter path of PLLP and PLLMB which can be used as EMC
> > clock source.
> > 
> > Signed-off-by: Joseph Lo <josephl@nvidia.com>
> > Signed-off-by: Thierry Reding <treding@nvidia.com>
> > ---
> >  drivers/clk/tegra/clk-tegra210.c         | 11 +++++++++++
> >  include/dt-bindings/clock/tegra210-car.h |  4 ++--
> >  2 files changed, 13 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c
> > index 45d54ead30bc..f99647b4a71f 100644
> > --- a/drivers/clk/tegra/clk-tegra210.c
> > +++ b/drivers/clk/tegra/clk-tegra210.c
> > @@ -3161,6 +3161,17 @@ static void __init tegra210_pll_init(void __iomem *clk_base,
> >  	clk_register_clkdev(clk, "pll_m_ud", NULL);
> >  	clks[TEGRA210_CLK_PLL_M_UD] = clk;
> >  
> > +	/* PLLMB_UD */
> > +	clk = clk_register_fixed_factor(NULL, "pll_mb_ud", "pll_mb",
> > +					CLK_SET_RATE_PARENT, 1, 1);
> > +	clk_register_clkdev(clk, "pll_mb_ud", NULL);
> > +	clks[TEGRA210_CLK_PLL_MB_UD] = clk;
> > +
> > +	/* PLLP_UD */
> > +	clk = clk_register_fixed_factor(NULL, "pll_p_ud", "pll_p",
> > +					0, 1, 1);
> > +	clks[TEGRA210_CLK_PLL_P_UD] = clk;
> 
> Isn't it possible to auto-enable the low-jitter bit when necessary
> during of the rate-change based on a given clock-rate?

I don't think so. These new clocks (pll_mb_ud and pll_p_ud) are parents
for the emc clock, so they are needed to properly reflect the position
of the emc clock in the clock tree.

Thierry
Dmitry Osipenko March 10, 2020, 5:50 p.m. UTC | #3 
10.03.2020 20:05, Thierry Reding пишет:
> On Tue, Mar 10, 2020 at 07:19:59PM +0300, Dmitry Osipenko wrote:
>> 10.03.2020 18:19, Thierry Reding пишет:
>>> From: Joseph Lo <josephl@nvidia.com>
>>>
>>> Introduce the low jitter path of PLLP and PLLMB which can be used as EMC
>>> clock source.
>>>
>>> Signed-off-by: Joseph Lo <josephl@nvidia.com>
>>> Signed-off-by: Thierry Reding <treding@nvidia.com>
>>> ---
>>>  drivers/clk/tegra/clk-tegra210.c         | 11 +++++++++++
>>>  include/dt-bindings/clock/tegra210-car.h |  4 ++--
>>>  2 files changed, 13 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c
>>> index 45d54ead30bc..f99647b4a71f 100644
>>> --- a/drivers/clk/tegra/clk-tegra210.c
>>> +++ b/drivers/clk/tegra/clk-tegra210.c
>>> @@ -3161,6 +3161,17 @@ static void __init tegra210_pll_init(void __iomem *clk_base,
>>>  	clk_register_clkdev(clk, "pll_m_ud", NULL);
>>>  	clks[TEGRA210_CLK_PLL_M_UD] = clk;
>>>  
>>> +	/* PLLMB_UD */
>>> +	clk = clk_register_fixed_factor(NULL, "pll_mb_ud", "pll_mb",
>>> +					CLK_SET_RATE_PARENT, 1, 1);
>>> +	clk_register_clkdev(clk, "pll_mb_ud", NULL);
>>> +	clks[TEGRA210_CLK_PLL_MB_UD] = clk;
>>> +
>>> +	/* PLLP_UD */
>>> +	clk = clk_register_fixed_factor(NULL, "pll_p_ud", "pll_p",
>>> +					0, 1, 1);
>>> +	clks[TEGRA210_CLK_PLL_P_UD] = clk;
>>
>> Isn't it possible to auto-enable the low-jitter bit when necessary
>> during of the rate-change based on a given clock-rate?
> 
> I don't think so. These new clocks (pll_mb_ud and pll_p_ud) are parents
> for the emc clock, so they are needed to properly reflect the position
> of the emc clock in the clock tree.

Okay, even if it's possible to do, I guess that won't be very compatible
with the firmware.
diff mbox series

Patch

diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c
index 45d54ead30bc..f99647b4a71f 100644
--- a/drivers/clk/tegra/clk-tegra210.c
+++ b/drivers/clk/tegra/clk-tegra210.c
@@ -3161,6 +3161,17 @@  static void __init tegra210_pll_init(void __iomem *clk_base,
 	clk_register_clkdev(clk, "pll_m_ud", NULL);
 	clks[TEGRA210_CLK_PLL_M_UD] = clk;
 
+	/* PLLMB_UD */
+	clk = clk_register_fixed_factor(NULL, "pll_mb_ud", "pll_mb",
+					CLK_SET_RATE_PARENT, 1, 1);
+	clk_register_clkdev(clk, "pll_mb_ud", NULL);
+	clks[TEGRA210_CLK_PLL_MB_UD] = clk;
+
+	/* PLLP_UD */
+	clk = clk_register_fixed_factor(NULL, "pll_p_ud", "pll_p",
+					0, 1, 1);
+	clks[TEGRA210_CLK_PLL_P_UD] = clk;
+
 	/* PLLU_VCO */
 	if (!tegra210_init_pllu()) {
 		clk = clk_register_fixed_rate(NULL, "pll_u_vco", "pll_ref", 0,
diff --git a/include/dt-bindings/clock/tegra210-car.h b/include/dt-bindings/clock/tegra210-car.h
index 7a8f10b9a66d..5c93b01156d4 100644
--- a/include/dt-bindings/clock/tegra210-car.h
+++ b/include/dt-bindings/clock/tegra210-car.h
@@ -351,8 +351,8 @@ 
 #define TEGRA210_CLK_PLL_P_OUT_XUSB 317
 #define TEGRA210_CLK_XUSB_SSP_SRC 318
 #define TEGRA210_CLK_PLL_RE_OUT1 319
-/* 320 */
-/* 321 */
+#define TEGRA210_CLK_PLL_MB_UD 320
+#define TEGRA210_CLK_PLL_P_UD 321
 #define TEGRA210_CLK_ISP 322
 #define TEGRA210_CLK_PLL_A_OUT_ADSP 323
 #define TEGRA210_CLK_PLL_A_OUT0_OUT_ADSP 324