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From:   Alexandre Courbot <acourbot@chromium.org>
Date:   Wed, 19 Sep 2018 16:32:22 +0900
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Subject: Re: [PATCH v9 1/5] venus: firmware: add routine to reset ARM9
To:     vgarodia@codeaurora.org
Cc:     Stanimir Varbanov <stanimir.varbanov@linaro.org>,
        Hans Verkuil <hverkuil@xs4all.nl>,
        Mauro Carvalho Chehab <mchehab@kernel.org>, robh@kernel.org,
        mark.rutland@arm.com, Andy Gross <andy.gross@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>, bjorn.andersson@linaro.org,
        Linux Media Mailing List <linux-media@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org,
        devicetree@vger.kernel.org
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On Wed, Sep 19, 2018 at 8:43 AM Vikash Garodia <vgarodia@codeaurora.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@codeaurora.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.

>   * @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.

>
>  #endif
> diff --git a/drivers/media/platform/qcom/venus/hfi_venus.c b/drivers/media/platform/qcom/venus/hfi_venus.c
> index 1240855..074837e 100644
> --- a/drivers/media/platform/qcom/venus/hfi_venus.c
> +++ b/drivers/media/platform/qcom/venus/hfi_venus.c
> @@ -19,7 +19,6 @@
>  #include <linux/interrupt.h>
>  #include <linux/iopoll.h>
>  #include <linux/kernel.h>
> -#include <linux/qcom_scm.h>
>  #include <linux/slab.h>
>
>  #include "core.h"
> @@ -27,6 +26,7 @@
>  #include "hfi_msgs.h"
>  #include "hfi_venus.h"
>  #include "hfi_venus_io.h"
> +#include "firmware.h"
>
>  #define HFI_MASK_QHDR_TX_TYPE          0xff000000
>  #define HFI_MASK_QHDR_RX_TYPE          0x00ff0000
> @@ -55,11 +55,6 @@
>  #define IFACEQ_VAR_LARGE_PKT_SIZE      512
>  #define IFACEQ_VAR_HUGE_PKT_SIZE       (1024 * 12)
>
> -enum tzbsp_video_state {
> -       TZBSP_VIDEO_STATE_SUSPEND = 0,
> -       TZBSP_VIDEO_STATE_RESUME
> -};
> -
>  struct hfi_queue_table_header {
>         u32 version;
>         u32 size;
> @@ -575,7 +570,7 @@ static int venus_power_off(struct venus_hfi_device *hdev)
>         if (!hdev->power_enabled)
>                 return 0;
>
> -       ret = qcom_scm_set_remote_state(TZBSP_VIDEO_STATE_SUSPEND, 0);
> +       ret = venus_set_hw_state_suspend(hdev->core);
>         if (ret)
>                 return ret;
>
> @@ -595,7 +590,7 @@ static int venus_power_on(struct venus_hfi_device *hdev)
>         if (hdev->power_enabled)
>                 return 0;
>
> -       ret = qcom_scm_set_remote_state(TZBSP_VIDEO_STATE_RESUME, 0);
> +       ret = venus_set_hw_state_resume(hdev->core);
>         if (ret)
>                 goto err;
>
> @@ -608,7 +603,7 @@ static int venus_power_on(struct venus_hfi_device *hdev)
>         return 0;
>
>  err_suspend:
> -       qcom_scm_set_remote_state(TZBSP_VIDEO_STATE_SUSPEND, 0);
> +       venus_set_hw_state_suspend(hdev->core);
>  err:
>         hdev->power_enabled = false;
>         return ret;
> diff --git a/drivers/media/platform/qcom/venus/hfi_venus_io.h b/drivers/media/platform/qcom/venus/hfi_venus_io.h
> index def0926..d69f51b 100644
> --- a/drivers/media/platform/qcom/venus/hfi_venus_io.h
> +++ b/drivers/media/platform/qcom/venus/hfi_venus_io.h
> @@ -112,6 +112,13 @@
>  #define WRAPPER_CPU_STATUS                     (WRAPPER_BASE + 0x2014)
>  #define WRAPPER_CPU_STATUS_WFI                 BIT(0)
>  #define WRAPPER_SW_RESET                       (WRAPPER_BASE + 0x3000)
> +#define WRAPPER_CPA_START_ADDR                 (WRAPPER_BASE + 0x1020)
> +#define WRAPPER_CPA_END_ADDR                   (WRAPPER_BASE + 0x1024)
> +#define WRAPPER_FW_START_ADDR                  (WRAPPER_BASE + 0x1028)
> +#define WRAPPER_FW_END_ADDR                    (WRAPPER_BASE + 0x102C)
> +#define WRAPPER_NONPIX_START_ADDR              (WRAPPER_BASE + 0x1030)
> +#define WRAPPER_NONPIX_END_ADDR                        (WRAPPER_BASE + 0x1034)
> +#define WRAPPER_A9SS_SW_RESET                  (WRAPPER_BASE + 0x3000)
>
>  /* Venus 4xx */
>  #define WRAPPER_VCODEC0_MMCC_POWER_STATUS      (WRAPPER_BASE + 0x90)
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>