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Message-ID: <175fcecf3be715d2a20b71746c648f1e@codeaurora.org>
Date: Wed, 19 Sep 2018 23:25:01 +0530
From: Vikash Garodia <vgarodia@...eaurora.org>
To: Stanimir Varbanov <stanimir.varbanov@...aro.org>
Cc: Alexandre Courbot <acourbot@...omium.org>,
Hans Verkuil <hverkuil@...all.nl>,
Mauro Carvalho Chehab <mchehab@...nel.org>, robh@...nel.org,
mark.rutland@....com, Andy Gross <andy.gross@...aro.org>,
Arnd Bergmann <arnd@...db.de>, bjorn.andersson@...aro.org,
Linux Media Mailing List <linux-media@...r.kernel.org>,
LKML <linux-kernel@...r.kernel.org>,
linux-arm-msm@...r.kernel.org, linux-soc@...r.kernel.org,
devicetree@...r.kernel.org, linux-media-owner@...r.kernel.org
Subject: Re: [PATCH v9 1/5] venus: firmware: add routine to reset ARM9
On 2018-09-19 20:30, Stanimir Varbanov wrote:
> Hi Alex,
>
> On 09/19/2018 10:32 AM, Alexandre Courbot wrote:
>> On Wed, Sep 19, 2018 at 8:43 AM Vikash Garodia
>> <vgarodia@...eaurora.org> wrote:
>>>
>>> Add routine to reset the ARM9 and brings it out of reset. Also
>>> abstract the Venus CPU state handling with a new function. This
>>> is in preparation to add PIL functionality in venus driver.
>>>
>>> Signed-off-by: Vikash Garodia <vgarodia@...eaurora.org>
>>> ---
>>> drivers/media/platform/qcom/venus/core.h | 2 ++
>>> drivers/media/platform/qcom/venus/firmware.c | 33
>>> ++++++++++++++++++++++++
>>> drivers/media/platform/qcom/venus/firmware.h | 11 ++++++++
>>> drivers/media/platform/qcom/venus/hfi_venus.c | 13 +++-------
>>> drivers/media/platform/qcom/venus/hfi_venus_io.h | 7 +++++
>>> 5 files changed, 57 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/drivers/media/platform/qcom/venus/core.h
>>> b/drivers/media/platform/qcom/venus/core.h
>>> index 2f02365..dfd5c10 100644
>>> --- a/drivers/media/platform/qcom/venus/core.h
>>> +++ b/drivers/media/platform/qcom/venus/core.h
>>> @@ -98,6 +98,7 @@ struct venus_caps {
>>> * @dev: convenience struct device pointer
>>> * @dev_dec: convenience struct device pointer for decoder device
>>> * @dev_enc: convenience struct device pointer for encoder device
>>> + * @no_tz: a flag that suggests presence of trustzone
>>
>> Looks like it suggests the absence of trustzone?
>>
>> Actually I would rename it as use_tz and set it if TrustZone is used.
>> This would avoid double-negative statements like what we see below.
>
> I find this suggestion reasonable.
Initially i planned to keep it as a positive flag. The reason behind
keeping it
as no_tz was to keep the default value of this flag to 0 indicating tz
is present
by default.
I can switch it to use_tz though and set it in firmware_init after the
presence of
firmware node is checked.
>>
>>> * @lock: a lock for this strucure
>>> * @instances: a list_head of all instances
>>> * @insts_count: num of instances
>>> @@ -129,6 +130,7 @@ struct venus_core {
>>> struct device *dev;
>>> struct device *dev_dec;
>>> struct device *dev_enc;
>>> + bool no_tz;
>>> struct mutex lock;
>>> struct list_head instances;
>>> atomic_t insts_count;
>>> diff --git a/drivers/media/platform/qcom/venus/firmware.c
>>> b/drivers/media/platform/qcom/venus/firmware.c
>>> index c4a5778..f2ae2f0 100644
>>> --- a/drivers/media/platform/qcom/venus/firmware.c
>>> +++ b/drivers/media/platform/qcom/venus/firmware.c
>>> @@ -22,10 +22,43 @@
>>> #include <linux/sizes.h>
>>> #include <linux/soc/qcom/mdt_loader.h>
>>>
>>> +#include "core.h"
>>> #include "firmware.h"
>>> +#include "hfi_venus_io.h"
>>>
>>> #define VENUS_PAS_ID 9
>>> #define VENUS_FW_MEM_SIZE (6 * SZ_1M)
>>> +#define VENUS_FW_START_ADDR 0x0
>>> +
>>> +static void venus_reset_cpu(struct venus_core *core)
>>> +{
>>> + void __iomem *base = core->base;
>>> +
>>> + writel(0, base + WRAPPER_FW_START_ADDR);
>>> + writel(VENUS_FW_MEM_SIZE, base + WRAPPER_FW_END_ADDR);
>>> + writel(0, base + WRAPPER_CPA_START_ADDR);
>>> + writel(VENUS_FW_MEM_SIZE, base + WRAPPER_CPA_END_ADDR);
>>> + writel(VENUS_FW_MEM_SIZE, base + WRAPPER_NONPIX_START_ADDR);
>>> + writel(VENUS_FW_MEM_SIZE, base + WRAPPER_NONPIX_END_ADDR);
>>> + writel(0x0, base + WRAPPER_CPU_CGC_DIS);
>>> + writel(0x0, base + WRAPPER_CPU_CLOCK_CONFIG);
>>> +
>>> + /* Bring ARM9 out of reset */
>>> + writel(0, base + WRAPPER_A9SS_SW_RESET);
>>> +}
>>> +
>>> +int venus_set_hw_state(struct venus_core *core, bool resume)
>>> +{
>>> + if (!core->no_tz)
>>
>> This is the kind of double negative statement I was referring do
>> above: "if we do not not have TrustZone". Turning it into
>>
>> if (core->use_tz)
>>
>> would save the reader a few neurons. :)
>>
>>> + return qcom_scm_set_remote_state(resume, 0);
>>> +
>>> + if (resume)
>>> + venus_reset_cpu(core);
>>> + else
>>> + writel(1, core->base + WRAPPER_A9SS_SW_RESET);
>>> +
>>> + return 0;
>>> +}
>>>
>>> int venus_boot(struct device *dev, const char *fwname)
>>> {
>>> diff --git a/drivers/media/platform/qcom/venus/firmware.h
>>> b/drivers/media/platform/qcom/venus/firmware.h
>>> index 428efb5..397570c 100644
>>> --- a/drivers/media/platform/qcom/venus/firmware.h
>>> +++ b/drivers/media/platform/qcom/venus/firmware.h
>>> @@ -18,5 +18,16 @@
>>>
>>> int venus_boot(struct device *dev, const char *fwname);
>>> int venus_shutdown(struct device *dev);
>>> +int venus_set_hw_state(struct venus_core *core, bool suspend);
>>> +
>>> +static inline int venus_set_hw_state_suspend(struct venus_core
>>> *core)
>>> +{
>>> + return venus_set_hw_state(core, false);
>>> +}
>>> +
>>> +static inline int venus_set_hw_state_resume(struct venus_core *core)
>>> +{
>>> + return venus_set_hw_state(core, true);
>>> +}
>>
>> I think these two venus_set_hw_state_suspend() and
>> venus_set_hw_state_resume() are superfluous, if you want to make the
>> state explicit you can also define an enum { SUSPEND, RESUME } to use
>> as argument of venus_set_hw_state() and call it directly.
>
> Infact this was by my request, and I wanted to avoid enum and have the
> type of the action in the function name and also avoid one extra
> function argument. Of course it is a matter of taste.
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