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Date: Fri, 20 May 2022 11:39:16 +0200
From: Ulf Hansson <ulf.hansson@...aro.org>
To: Maulik Shah <quic_mkshah@...cinc.com>
Cc: bjorn.andersson@...aro.org, linux-arm-msm@...r.kernel.org,
linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
rafael@...nel.org, daniel.lezcano@...aro.org,
quic_lsrao@...cinc.com, quic_rjendra@...cinc.com
Subject: Re: [PATCH v2 6/6] soc: qcom: rpmh-rsc: Write CONTROL_TCS with next
timer wakeup
On Wed, 11 May 2022 at 15:17, Maulik Shah <quic_mkshah@...cinc.com> wrote:
>
> The next wakeup timer value needs to be set in always on domain timer
> as the arch timer interrupt can not wakeup the SoC if after the deepest
> CPUidle states the SoC also enters deepest low power state.
>
> To wakeup the SoC in such scenarios the earliest wakeup time is set in
> CONTROL_TCS and the firmware takes care of setting up its own timer in
> always on domain with next wakeup time. The timer wakes up the RSC and
> sets resources back to wake state.
>
> Signed-off-by: Maulik Shah <quic_mkshah@...cinc.com>
I didn't forget to review this, but please allow me a few more days to
think a little bit more about this.
Kind regards
Uffe
> ---
> drivers/soc/qcom/rpmh-internal.h | 3 ++
> drivers/soc/qcom/rpmh-rsc.c | 61 ++++++++++++++++++++++++++++++++++++++++
> drivers/soc/qcom/rpmh.c | 4 ++-
> 3 files changed, 67 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/soc/qcom/rpmh-internal.h b/drivers/soc/qcom/rpmh-internal.h
> index 7866bb1..39f5358 100644
> --- a/drivers/soc/qcom/rpmh-internal.h
> +++ b/drivers/soc/qcom/rpmh-internal.h
> @@ -112,6 +112,7 @@ struct rpmh_ctrlr {
> * @tcs_wait: Wait queue used to wait for @tcs_in_use to free up a
> * slot
> * @client: Handle to the DRV's client.
> + * @dev: RSC device.
> */
> struct rsc_drv {
> const char *name;
> @@ -127,12 +128,14 @@ struct rsc_drv {
> spinlock_t lock;
> wait_queue_head_t tcs_wait;
> struct rpmh_ctrlr client;
> + struct device *dev;
> };
>
> int rpmh_rsc_send_data(struct rsc_drv *drv, const struct tcs_request *msg);
> int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv,
> const struct tcs_request *msg);
> void rpmh_rsc_invalidate(struct rsc_drv *drv);
> +void rpmh_rsc_write_next_wakeup(struct rsc_drv *drv);
>
> void rpmh_tx_done(const struct tcs_request *msg, int r);
> int rpmh_flush(struct rpmh_ctrlr *ctrlr);
> diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
> index 8e01697..25b838b 100644
> --- a/drivers/soc/qcom/rpmh-rsc.c
> +++ b/drivers/soc/qcom/rpmh-rsc.c
> @@ -12,6 +12,7 @@
> #include <linux/io.h>
> #include <linux/iopoll.h>
> #include <linux/kernel.h>
> +#include <linux/ktime.h>
> #include <linux/list.h>
> #include <linux/module.h>
> #include <linux/notifier.h>
> @@ -25,6 +26,7 @@
> #include <linux/spinlock.h>
> #include <linux/wait.h>
>
> +#include <clocksource/arm_arch_timer.h>
> #include <soc/qcom/cmd-db.h>
> #include <soc/qcom/tcs.h>
> #include <dt-bindings/soc/qcom,rpmh-rsc.h>
> @@ -49,6 +51,14 @@
> #define DRV_NCPT_MASK 0x1F
> #define DRV_NCPT_SHIFT 27
>
> +/* Offsets for CONTROL TCS Registers */
> +#define RSC_DRV_CTL_TCS_DATA_HI 0x38
> +#define RSC_DRV_CTL_TCS_DATA_HI_MASK 0xFFFFFF
> +#define RSC_DRV_CTL_TCS_DATA_HI_VALID BIT(31)
> +#define RSC_DRV_CTL_TCS_DATA_LO 0x40
> +#define RSC_DRV_CTL_TCS_DATA_LO_MASK 0xFFFFFFFF
> +#define RSC_DRV_CTL_TCS_DATA_SIZE 32
> +
> /* Offsets for common TCS Registers, one bit per TCS */
> #define RSC_DRV_IRQ_ENABLE 0x00
> #define RSC_DRV_IRQ_STATUS 0x04
> @@ -142,6 +152,14 @@
> * +---------------------------------------------------+
> */
>
> +#define USECS_TO_CYCLES(time_usecs) \
> + xloops_to_cycles((time_usecs) * 0x10C7UL)
> +
> +static inline unsigned long xloops_to_cycles(unsigned long xloops)
> +{
> + return (xloops * loops_per_jiffy * HZ) >> 32;
> +}
> +
> static inline void __iomem *
> tcs_reg_addr(const struct rsc_drv *drv, int reg, int tcs_id)
> {
> @@ -757,6 +775,48 @@ static bool rpmh_rsc_ctrlr_is_busy(struct rsc_drv *drv)
> }
>
> /**
> + * rpmh_rsc_write_next_wakeup() - Write next wakeup in CONTROL_TCS.
> + * @drv: The controller
> + *
> + * Writes maximum wakeup cycles when called from suspend.
> + * Writes earliest hrtimer wakeup when called from idle.
> + */
> +void rpmh_rsc_write_next_wakeup(struct rsc_drv *drv)
> +{
> + ktime_t now, wakeup;
> + u64 wakeup_us, wakeup_cycles = ~0;
> + u32 lo, hi;
> +
> + if (!drv->tcs[CONTROL_TCS].num_tcs || !drv->genpd_nb.notifier_call)
> + return;
> +
> + /* Set highest time when system (timekeeping) is suspended */
> + if (system_state == SYSTEM_SUSPEND)
> + goto exit;
> +
> + /* Find the earliest hrtimer wakeup from online cpus */
> + wakeup = dev_pm_genpd_get_next_hrtimer(drv->dev);
> +
> + /* Find the relative wakeup in kernel time scale */
> + now = ktime_get();
> + wakeup = ktime_sub(wakeup, now);
> + wakeup_us = ktime_to_us(wakeup);
> +
> + /* Convert the wakeup to arch timer scale */
> + wakeup_cycles = USECS_TO_CYCLES(wakeup_us);
> + wakeup_cycles += arch_timer_read_counter();
> +
> +exit:
> + lo = wakeup_cycles & RSC_DRV_CTL_TCS_DATA_LO_MASK;
> + hi = wakeup_cycles >> RSC_DRV_CTL_TCS_DATA_SIZE;
> + hi &= RSC_DRV_CTL_TCS_DATA_HI_MASK;
> + hi |= RSC_DRV_CTL_TCS_DATA_HI_VALID;
> +
> + writel_relaxed(lo, drv->base + RSC_DRV_CTL_TCS_DATA_LO);
> + writel_relaxed(hi, drv->base + RSC_DRV_CTL_TCS_DATA_HI);
> +}
> +
> +/**
> * rpmh_rsc_cpu_pm_callback() - Check if any of the AMCs are busy.
> * @nfb: Pointer to the notifier block in struct rsc_drv.
> * @action: CPU_PM_ENTER, CPU_PM_ENTER_FAILED, or CPU_PM_EXIT.
> @@ -1035,6 +1095,7 @@ static int rpmh_rsc_probe(struct platform_device *pdev)
> INIT_LIST_HEAD(&drv->client.batch_cache);
>
> dev_set_drvdata(&pdev->dev, drv);
> + drv->dev = &pdev->dev;
>
> ret = devm_of_platform_populate(&pdev->dev);
> if (ret && pdev->dev.pm_domain) {
> diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
> index 01765ee..3a53ed9 100644
> --- a/drivers/soc/qcom/rpmh.c
> +++ b/drivers/soc/qcom/rpmh.c
> @@ -450,7 +450,7 @@ int rpmh_flush(struct rpmh_ctrlr *ctrlr)
>
> if (!ctrlr->dirty) {
> pr_debug("Skipping flush, TCS has latest data.\n");
> - goto exit;
> + goto write_next_wakeup;
> }
>
> /* Invalidate the TCSes first to avoid stale data */
> @@ -479,6 +479,8 @@ int rpmh_flush(struct rpmh_ctrlr *ctrlr)
>
> ctrlr->dirty = false;
>
> +write_next_wakeup:
> + rpmh_rsc_write_next_wakeup(ctrlr_to_drv(ctrlr));
> exit:
> spin_unlock(&ctrlr->cache_lock);
> return ret;
> --
> 2.7.4
>
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