* [PATCH] clk: stm32f4: don't assume 48MHz clock is derived from primary PLL
@ 2016-09-08 7:01 Andrea Merello
2016-09-09 9:57 ` Alexandre Torgue
0 siblings, 1 reply; 5+ messages in thread
From: Andrea Merello @ 2016-09-08 7:01 UTC (permalink / raw)
To: linux-arm-kernel
This driver just look at the PLLs configurations set by the
bootloader, but it assumes the 48MHz clock is derived from the primary
PLL; however using PLLSAI is another option for generating the 48MHz
clock.
This patch make the driver to check for this, and eventually adjust the
clock tree accordingly
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Bruno Herrera <bruherrera@gmail.com>
---
drivers/clk/clk-stm32f4.c | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)
diff --git a/drivers/clk/clk-stm32f4.c b/drivers/clk/clk-stm32f4.c
index 02d6810..7f1ba8f 100644
--- a/drivers/clk/clk-stm32f4.c
+++ b/drivers/clk/clk-stm32f4.c
@@ -24,6 +24,7 @@
#include <linux/of.h>
#include <linux/of_address.h>
+#define STM32F4_RCC_CR 0x00
#define STM32F4_RCC_PLLCFGR 0x04
#define STM32F4_RCC_CFGR 0x08
#define STM32F4_RCC_AHB1ENR 0x30
@@ -31,6 +32,8 @@
#define STM32F4_RCC_AHB3ENR 0x38
#define STM32F4_RCC_APB1ENR 0x40
#define STM32F4_RCC_APB2ENR 0x44
+#define STM32F4_RCC_PLLSAICFGR 0x88
+#define STM32F4_RCC_DCKCFGR 0x8C
struct stm32f4_gate_data {
u8 offset;
@@ -238,16 +241,35 @@ static struct clk *clk_register_apb_mul(struct device *dev, const char *name,
static void stm32f4_rcc_register_pll(const char *hse_clk, const char *hsi_clk)
{
unsigned long pllcfgr = readl(base + STM32F4_RCC_PLLCFGR);
-
+ unsigned long pllsaicfgr = readl(base + STM32F4_RCC_PLLSAICFGR);
+ unsigned long dckcfgr = readl(base + STM32F4_RCC_DCKCFGR);
+ unsigned long rcccr = readl(base + STM32F4_RCC_CR);
+ bool saien = rcccr & BIT(28);
unsigned long pllm = pllcfgr & 0x3f;
unsigned long plln = (pllcfgr >> 6) & 0x1ff;
unsigned long pllp = BIT(((pllcfgr >> 16) & 3) + 1);
const char *pllsrc = pllcfgr & BIT(22) ? hse_clk : hsi_clk;
unsigned long pllq = (pllcfgr >> 24) & 0xf;
+ bool src48_sai = dckcfgr & BIT(27);
+ unsigned long pllsain = (pllsaicfgr >> 6) & 0x1ff;
+ unsigned long pllsaip = BIT(((pllsaicfgr >> 16) & 3) + 1);
clk_register_fixed_factor(NULL, "vco", pllsrc, 0, plln, pllm);
clk_register_fixed_factor(NULL, "pll", "vco", 0, 1, pllp);
- clk_register_fixed_factor(NULL, "pll48", "vco", 0, 1, pllq);
+
+ if (src48_sai && !saien) {
+ pr_err("48MHz derived from SAI PLL, but SAI PLL disabled (blame the bootloader)\n");
+ return;
+ }
+
+ if (saien)
+ clk_register_fixed_factor(NULL, "sai",
+ pllsrc, 0, pllsain, pllm);
+
+ if (src48_sai)
+ clk_register_fixed_factor(NULL, "pll48", "sai", 0, 1, pllsaip);
+ else
+ clk_register_fixed_factor(NULL, "pll48", "vco", 0, 1, pllq);
}
/*
--
2.7.4
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH] clk: stm32f4: don't assume 48MHz clock is derived from primary PLL
2016-09-08 7:01 [PATCH] clk: stm32f4: don't assume 48MHz clock is derived from primary PLL Andrea Merello
@ 2016-09-09 9:57 ` Alexandre Torgue
2016-09-12 6:48 ` Andrea Merello
0 siblings, 1 reply; 5+ messages in thread
From: Alexandre Torgue @ 2016-09-09 9:57 UTC (permalink / raw)
To: linux-arm-kernel
Hi Andrea,
On 09/08/2016 09:01 AM, Andrea Merello wrote:
> This driver just look at the PLLs configurations set by the
> bootloader, but it assumes the 48MHz clock is derived from the primary
> PLL; however using PLLSAI is another option for generating the 48MHz
> clock.
>
> This patch make the driver to check for this, and eventually adjust the
> clock tree accordingly
Another patch-set is ongoing concerning RTC clock for stm32f4. It is
developed by Gabriel Fernandez (I add him directly in this reply).
Can you check with him how he plans to manage this RTC clock in order to
have something similar / coherent for SAI clocks, 48MHz ....
Concerning this patch,
When I look at the clock tree I see that 48 MHz is only provided by pll
named "PLL". So If you use PLL SAI to provide a clock at 48 MHz, you
actually use SAI_A or SAI_B clock. I'm right ?
I think we need to have something more configurable. Each special clock
(SAI / RTC /LCd ...) have to be configurable and each "parents" (PLL /
PLLI2S / PLLSAI) should be described at least in the driver.
Gabriel,
Can you send a draft of your patch-set for RTC clock to Andrea, in order
to discuss about this topic.
Thanks
Alex
>
> Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
> Cc: Michael Turquette <mturquette@baylibre.com>
> Cc: Stephen Boyd <sboyd@codeaurora.org>
> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> Cc: Alexandre Torgue <alexandre.torgue@st.com>
> Cc: Bruno Herrera <bruherrera@gmail.com>
> ---
> drivers/clk/clk-stm32f4.c | 26 ++++++++++++++++++++++++--
> 1 file changed, 24 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/clk/clk-stm32f4.c b/drivers/clk/clk-stm32f4.c
> index 02d6810..7f1ba8f 100644
> --- a/drivers/clk/clk-stm32f4.c
> +++ b/drivers/clk/clk-stm32f4.c
> @@ -24,6 +24,7 @@
> #include <linux/of.h>
> #include <linux/of_address.h>
>
> +#define STM32F4_RCC_CR 0x00
> #define STM32F4_RCC_PLLCFGR 0x04
> #define STM32F4_RCC_CFGR 0x08
> #define STM32F4_RCC_AHB1ENR 0x30
> @@ -31,6 +32,8 @@
> #define STM32F4_RCC_AHB3ENR 0x38
> #define STM32F4_RCC_APB1ENR 0x40
> #define STM32F4_RCC_APB2ENR 0x44
> +#define STM32F4_RCC_PLLSAICFGR 0x88
> +#define STM32F4_RCC_DCKCFGR 0x8C
>
> struct stm32f4_gate_data {
> u8 offset;
> @@ -238,16 +241,35 @@ static struct clk *clk_register_apb_mul(struct device *dev, const char *name,
> static void stm32f4_rcc_register_pll(const char *hse_clk, const char *hsi_clk)
> {
> unsigned long pllcfgr = readl(base + STM32F4_RCC_PLLCFGR);
> -
> + unsigned long pllsaicfgr = readl(base + STM32F4_RCC_PLLSAICFGR);
> + unsigned long dckcfgr = readl(base + STM32F4_RCC_DCKCFGR);
> + unsigned long rcccr = readl(base + STM32F4_RCC_CR);
> + bool saien = rcccr & BIT(28);
> unsigned long pllm = pllcfgr & 0x3f;
> unsigned long plln = (pllcfgr >> 6) & 0x1ff;
> unsigned long pllp = BIT(((pllcfgr >> 16) & 3) + 1);
> const char *pllsrc = pllcfgr & BIT(22) ? hse_clk : hsi_clk;
> unsigned long pllq = (pllcfgr >> 24) & 0xf;
> + bool src48_sai = dckcfgr & BIT(27);
> + unsigned long pllsain = (pllsaicfgr >> 6) & 0x1ff;
> + unsigned long pllsaip = BIT(((pllsaicfgr >> 16) & 3) + 1);
>
> clk_register_fixed_factor(NULL, "vco", pllsrc, 0, plln, pllm);
> clk_register_fixed_factor(NULL, "pll", "vco", 0, 1, pllp);
> - clk_register_fixed_factor(NULL, "pll48", "vco", 0, 1, pllq);
> +
> + if (src48_sai && !saien) {
> + pr_err("48MHz derived from SAI PLL, but SAI PLL disabled (blame the bootloader)\n");
> + return;
> + }
> +
> + if (saien)
> + clk_register_fixed_factor(NULL, "sai",
> + pllsrc, 0, pllsain, pllm);
> +
> + if (src48_sai)
> + clk_register_fixed_factor(NULL, "pll48", "sai", 0, 1, pllsaip);
> + else
> + clk_register_fixed_factor(NULL, "pll48", "vco", 0, 1, pllq);
> }
>
> /*
>
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH] clk: stm32f4: don't assume 48MHz clock is derived from primary PLL
2016-09-09 9:57 ` Alexandre Torgue
@ 2016-09-12 6:48 ` Andrea Merello
2016-11-02 0:44 ` Stephen Boyd
0 siblings, 1 reply; 5+ messages in thread
From: Andrea Merello @ 2016-09-12 6:48 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Sep 9, 2016 at 11:57 AM, Alexandre Torgue
<alexandre.torgue@st.com> wrote:
> Hi Andrea,
>
> On 09/08/2016 09:01 AM, Andrea Merello wrote:
>>
>> This driver just look at the PLLs configurations set by the
>> bootloader, but it assumes the 48MHz clock is derived from the primary
>> PLL; however using PLLSAI is another option for generating the 48MHz
>> clock.
>>
>> This patch make the driver to check for this, and eventually adjust the
>> clock tree accordingly
>
>
> Another patch-set is ongoing concerning RTC clock for stm32f4. It is
> developed by Gabriel Fernandez (I add him directly in this reply).
> Can you check with him how he plans to manage this RTC clock in order to
> have something similar / coherent for SAI clocks, 48MHz ....
>
> Concerning this patch,
> When I look at the clock tree I see that 48 MHz is only provided by pll
> named "PLL". So If you use PLL SAI to provide a clock at 48 MHz, you
> actually use SAI_A or SAI_B clock. I'm right ?
No, SAI_A and SAI_B are two other clocks output, that comes from
PLLSAI through other divisors and muxes; here I simply look at if the
bootloader selected the "PLL48CLK" output of the SAI PLL instead of
the "PLL48CLK" of the primary PLL.
> I think we need to have something more configurable. Each special clock (SAI
> / RTC /LCd ...) have to be configurable and each "parents" (PLL / PLLI2S /
> PLLSAI) should be described at least in the driver.
Yes, there are probably other possible clock configurations that the
driver does not recognize yet; I just added this one because I found
it useful in real-world scenario (USB/SDcard working and core running
at the max speed at the same time).
>
> Gabriel,
>
> Can you send a draft of your patch-set for RTC clock to Andrea, in order to
> discuss about this topic.
>
> Thanks
>
> Alex
>
>
>
>>
>> Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
>> Cc: Michael Turquette <mturquette@baylibre.com>
>> Cc: Stephen Boyd <sboyd@codeaurora.org>
>> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
>> Cc: Alexandre Torgue <alexandre.torgue@st.com>
>> Cc: Bruno Herrera <bruherrera@gmail.com>
>> ---
>> drivers/clk/clk-stm32f4.c | 26 ++++++++++++++++++++++++--
>> 1 file changed, 24 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/clk/clk-stm32f4.c b/drivers/clk/clk-stm32f4.c
>> index 02d6810..7f1ba8f 100644
>> --- a/drivers/clk/clk-stm32f4.c
>> +++ b/drivers/clk/clk-stm32f4.c
>> @@ -24,6 +24,7 @@
>> #include <linux/of.h>
>> #include <linux/of_address.h>
>>
>> +#define STM32F4_RCC_CR 0x00
>> #define STM32F4_RCC_PLLCFGR 0x04
>> #define STM32F4_RCC_CFGR 0x08
>> #define STM32F4_RCC_AHB1ENR 0x30
>> @@ -31,6 +32,8 @@
>> #define STM32F4_RCC_AHB3ENR 0x38
>> #define STM32F4_RCC_APB1ENR 0x40
>> #define STM32F4_RCC_APB2ENR 0x44
>> +#define STM32F4_RCC_PLLSAICFGR 0x88
>> +#define STM32F4_RCC_DCKCFGR 0x8C
>>
>> struct stm32f4_gate_data {
>> u8 offset;
>> @@ -238,16 +241,35 @@ static struct clk *clk_register_apb_mul(struct
>> device *dev, const char *name,
>> static void stm32f4_rcc_register_pll(const char *hse_clk, const char
>> *hsi_clk)
>> {
>> unsigned long pllcfgr = readl(base + STM32F4_RCC_PLLCFGR);
>> -
>> + unsigned long pllsaicfgr = readl(base + STM32F4_RCC_PLLSAICFGR);
>> + unsigned long dckcfgr = readl(base + STM32F4_RCC_DCKCFGR);
>> + unsigned long rcccr = readl(base + STM32F4_RCC_CR);
>> + bool saien = rcccr & BIT(28);
>> unsigned long pllm = pllcfgr & 0x3f;
>> unsigned long plln = (pllcfgr >> 6) & 0x1ff;
>> unsigned long pllp = BIT(((pllcfgr >> 16) & 3) + 1);
>> const char *pllsrc = pllcfgr & BIT(22) ? hse_clk : hsi_clk;
>> unsigned long pllq = (pllcfgr >> 24) & 0xf;
>> + bool src48_sai = dckcfgr & BIT(27);
>> + unsigned long pllsain = (pllsaicfgr >> 6) & 0x1ff;
>> + unsigned long pllsaip = BIT(((pllsaicfgr >> 16) & 3) + 1);
>>
>> clk_register_fixed_factor(NULL, "vco", pllsrc, 0, plln, pllm);
>> clk_register_fixed_factor(NULL, "pll", "vco", 0, 1, pllp);
>> - clk_register_fixed_factor(NULL, "pll48", "vco", 0, 1, pllq);
>> +
>> + if (src48_sai && !saien) {
>> + pr_err("48MHz derived from SAI PLL, but SAI PLL disabled
>> (blame the bootloader)\n");
>> + return;
>> + }
>> +
>> + if (saien)
>> + clk_register_fixed_factor(NULL, "sai",
>> + pllsrc, 0, pllsain, pllm);
>> +
>> + if (src48_sai)
>> + clk_register_fixed_factor(NULL, "pll48", "sai", 0, 1,
>> pllsaip);
>> + else
>> + clk_register_fixed_factor(NULL, "pll48", "vco", 0, 1,
>> pllq);
>> }
>>
>> /*
>>
>
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH] clk: stm32f4: don't assume 48MHz clock is derived from primary PLL
2016-09-12 6:48 ` Andrea Merello
@ 2016-11-02 0:44 ` Stephen Boyd
2016-11-02 8:09 ` Gabriel Fernandez
0 siblings, 1 reply; 5+ messages in thread
From: Stephen Boyd @ 2016-11-02 0:44 UTC (permalink / raw)
To: linux-arm-kernel
On 09/12, Andrea Merello wrote:
> On Fri, Sep 9, 2016 at 11:57 AM, Alexandre Torgue
> <alexandre.torgue@st.com> wrote:
> > Hi Andrea,
> >
> > On 09/08/2016 09:01 AM, Andrea Merello wrote:
> >>
> >> This driver just look at the PLLs configurations set by the
> >> bootloader, but it assumes the 48MHz clock is derived from the primary
> >> PLL; however using PLLSAI is another option for generating the 48MHz
> >> clock.
> >>
> >> This patch make the driver to check for this, and eventually adjust the
> >> clock tree accordingly
> >
> >
> > Another patch-set is ongoing concerning RTC clock for stm32f4. It is
> > developed by Gabriel Fernandez (I add him directly in this reply).
> > Can you check with him how he plans to manage this RTC clock in order to
> > have something similar / coherent for SAI clocks, 48MHz ....
> >
> > Concerning this patch,
> > When I look at the clock tree I see that 48 MHz is only provided by pll
> > named "PLL". So If you use PLL SAI to provide a clock at 48 MHz, you
> > actually use SAI_A or SAI_B clock. I'm right ?
>
> No, SAI_A and SAI_B are two other clocks output, that comes from
> PLLSAI through other divisors and muxes; here I simply look at if the
> bootloader selected the "PLL48CLK" output of the SAI PLL instead of
> the "PLL48CLK" of the primary PLL.
>
> > I think we need to have something more configurable. Each special clock (SAI
> > / RTC /LCd ...) have to be configurable and each "parents" (PLL / PLLI2S /
> > PLLSAI) should be described at least in the driver.
>
> Yes, there are probably other possible clock configurations that the
> driver does not recognize yet; I just added this one because I found
> it useful in real-world scenario (USB/SDcard working and core running
> at the max speed at the same time).
>
> >
> > Gabriel,
> >
> > Can you send a draft of your patch-set for RTC clock to Andrea, in order to
> > discuss about this topic.
> >
> > Thanks
I know this is a couple months old, but the RTC patches have been
applied. Please resend this patch rebased onto clk-next and
restart this discussion if this is still important.
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH] clk: stm32f4: don't assume 48MHz clock is derived from primary PLL
2016-11-02 0:44 ` Stephen Boyd
@ 2016-11-02 8:09 ` Gabriel Fernandez
0 siblings, 0 replies; 5+ messages in thread
From: Gabriel Fernandez @ 2016-11-02 8:09 UTC (permalink / raw)
To: linux-arm-kernel
On 11/02/2016 01:44 AM, Stephen Boyd wrote:
> On 09/12, Andrea Merello wrote:
>> On Fri, Sep 9, 2016 at 11:57 AM, Alexandre Torgue
>> <alexandre.torgue@st.com> wrote:
>>> Hi Andrea,
>>>
>>> On 09/08/2016 09:01 AM, Andrea Merello wrote:
>>>> This driver just look at the PLLs configurations set by the
>>>> bootloader, but it assumes the 48MHz clock is derived from the primary
>>>> PLL; however using PLLSAI is another option for generating the 48MHz
>>>> clock.
>>>>
>>>> This patch make the driver to check for this, and eventually adjust the
>>>> clock tree accordingly
>>>
>>> Another patch-set is ongoing concerning RTC clock for stm32f4. It is
>>> developed by Gabriel Fernandez (I add him directly in this reply).
>>> Can you check with him how he plans to manage this RTC clock in order to
>>> have something similar / coherent for SAI clocks, 48MHz ....
>>>
>>> Concerning this patch,
>>> When I look at the clock tree I see that 48 MHz is only provided by pll
>>> named "PLL". So If you use PLL SAI to provide a clock at 48 MHz, you
>>> actually use SAI_A or SAI_B clock. I'm right ?
>> No, SAI_A and SAI_B are two other clocks output, that comes from
>> PLLSAI through other divisors and muxes; here I simply look at if the
>> bootloader selected the "PLL48CLK" output of the SAI PLL instead of
>> the "PLL48CLK" of the primary PLL.
>>
>>> I think we need to have something more configurable. Each special clock (SAI
>>> / RTC /LCd ...) hav0000000000000000000000000000000000000001e to be configurable and each "parents" (PLL / PLLI2S /
>>> PLLSAI) should be described at least in the driver.
>> Yes, there are probably other possible clock configurations that the
>> driver does not recognize yet; I just added this one because I found
>> it useful in real-world scenario (USB/SDcard working and core running
>> at the max speed at the same time).
>>
>>> Gabriel,
>>>
>>> Can you send a draft of your patch-set for RTC clock to Andrea, in order to
>>> discuss about this topic.
>>>
>>> Thanks
> I know this is a couple months old, but the RTC patches have been
> applied. Please resend this patch rebased onto clk-next and
> restart this discussion if this is still important.
>
Hi Stephen & Andrea,
As discuss with Andrea, i will send a second patch-set to introduce
PLL-I2S & PLL-SAI (it will include the management of the 48 Mhz Clock)
I will probably send it today or tomorrow.
Thanks
Best Regard.
Gabriel
^ permalink raw reply [flat|nested] 5+ messages in thread
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2016-09-08 7:01 [PATCH] clk: stm32f4: don't assume 48MHz clock is derived from primary PLL Andrea Merello
2016-09-09 9:57 ` Alexandre Torgue
2016-09-12 6:48 ` Andrea Merello
2016-11-02 0:44 ` Stephen Boyd
2016-11-02 8:09 ` Gabriel Fernandez
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