On Wed, 19 Aug 2020 07:59:23 -0500
Adam Ford <aford173@xxxxxxxxx> wrote:
> The bandgap sensor can be idled when the processor is too, but it
> isn't currently being done, so the power consumption of OMAP3
> boards can elevated if the bangap sensor is enabled.
>
> This patch attempts to use some additional power management
> to idle the clock to the bandgap when not needed.
>
> Signed-off-by: Adam Ford <aford173@xxxxxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> ---
> V2: Fix issue where variable stating the suspend mode isn't being
> properly set and cleared.
>
I get
root@(none):/# cat /sys/class/thermal/thermal_zone0/type
cpu_thermal
root@(none):/# cat /sys/class/thermal/thermal_zone0/temp
50000
root@(none):/# cat /sys/class/thermal/thermal_zone1/
available_policies mode subsystem/
integral_cutoff offset sustainable_power
k_d passive temp
k_i policy type
k_po power/ uevent
k_pu slope
root@(none):/# cat /sys/class/thermal/thermal_zone1/type
bq27000-battery
root@(none):/# cat /sys/kernel/debug/pm_debug/count
usbhost_pwrdm (ON),OFF:3459,RET:635,INA:0,ON:4095,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
sgx_pwrdm (OFF),OFF:1,RET:0,INA:1,ON:2,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
core_pwrdm (ON),OFF:86,RET:7,INA:0,ON:94,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0
per_pwrdm (ON),OFF:1518,RET:64,INA:0,ON:1583,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
dss_pwrdm (ON),OFF:3459,RET:635,INA:0,ON:4095,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
cam_pwrdm (OFF),OFF:1,RET:1,INA:0,ON:2,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
neon_pwrdm (ON),OFF:2845,RET:1131,INA:119,ON:4096,RET-LOGIC-OFF:0
mpu_pwrdm (ON),OFF:2845,RET:1130,INA:119,ON:4095,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
iva2_pwrdm (OFF),OFF:1,RET:1,INA:0,ON:2,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0,RET-MEMBANK3-OFF:0,RET-MEMBANK4-OFF:0
usbhost_clkdm->usbhost_pwrdm (1)
sgx_clkdm->sgx_pwrdm (0)
per_clkdm->per_pwrdm (13)
cam_clkdm->cam_pwrdm (0)
dss_clkdm->dss_pwrdm (1)
d2d_clkdm->core_pwrdm (0)
iva2_clkdm->iva2_pwrdm (0)
mpu_clkdm->mpu_pwrdm (0)
core_l4_clkdm->core_pwrdm (20)
core_l3_clkdm->core_pwrdm (1)
neon_clkdm->neon_pwrdm (0)
root@(none):/#
So things still turn off.
Tested-by: Andreas Kemnade <andreas@xxxxxxxxxxxx> # GTA04
> diff --git a/drivers/thermal/ti-soc-thermal/ti-bandgap.c b/drivers/thermal/ti-soc-thermal/ti-bandgap.c
> index ab19ceff6e2a..9404631bea4d 100644
> --- a/drivers/thermal/ti-soc-thermal/ti-bandgap.c
> +++ b/drivers/thermal/ti-soc-thermal/ti-bandgap.c
> @@ -25,10 +25,18 @@
> #include <linux/of_platform.h>
> #include <linux/of_irq.h>
> #include <linux/io.h>
> +#include <linux/cpu_pm.h>
> +#include <linux/device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/pm.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
>
> #include "ti-bandgap.h"
>
> static int ti_bandgap_force_single_read(struct ti_bandgap *bgp, int id);
> +static int bandgap_omap_cpu_notifier(struct notifier_block *nb,
> + unsigned long cmd, void *v);
>
> /*** Helper functions to access registers and their bitfields ***/
>
> @@ -1008,6 +1016,9 @@ int ti_bandgap_probe(struct platform_device *pdev)
> }
> }
>
> + bgp->nb.notifier_call = bandgap_omap_cpu_notifier;
> + cpu_pm_register_notifier(&bgp->nb);
> +
> return 0;
>
> remove_last_cooling:
> @@ -1041,7 +1052,9 @@ int ti_bandgap_remove(struct platform_device *pdev)
> struct ti_bandgap *bgp = platform_get_drvdata(pdev);
> int i;
>
> - /* First thing is to remove sensor interfaces */
> + cpu_pm_unregister_notifier(&bgp->nb);
> +
> + /* Remove sensor interfaces */
> for (i = 0; i < bgp->conf->sensor_count; i++) {
> if (bgp->conf->sensors[i].unregister_cooling)
> bgp->conf->sensors[i].unregister_cooling(bgp, i);
> @@ -1150,9 +1163,43 @@ static int ti_bandgap_suspend(struct device *dev)
> if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
> clk_disable_unprepare(bgp->fclock);
>
> + bgp->is_suspended = true;
> +
> return err;
> }
>
> +static int bandgap_omap_cpu_notifier(struct notifier_block *nb,
> + unsigned long cmd, void *v)
> +{
> + struct ti_bandgap *bgp;
> +
> + bgp = container_of(nb, struct ti_bandgap, nb);
> +
> + spin_lock(&bgp->lock);
> + switch (cmd) {
> + case CPU_CLUSTER_PM_ENTER:
> + if (bgp->is_suspended)
> + break;
> + ti_bandgap_save_ctxt(bgp);
> + ti_bandgap_power(bgp, false);
> + if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
> + clk_disable(bgp->fclock);
> + break;
> + case CPU_CLUSTER_PM_ENTER_FAILED:
> + case CPU_CLUSTER_PM_EXIT:
> + if (bgp->is_suspended)
> + break;
> + if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
> + clk_enable(bgp->fclock);
> + ti_bandgap_power(bgp, true);
> + ti_bandgap_restore_ctxt(bgp);
> + break;
> + }
> + spin_unlock(&bgp->lock);
> +
> + return NOTIFY_OK;
> +}
> +
> static int ti_bandgap_resume(struct device *dev)
> {
> struct ti_bandgap *bgp = dev_get_drvdata(dev);
> @@ -1161,6 +1208,7 @@ static int ti_bandgap_resume(struct device *dev)
> clk_prepare_enable(bgp->fclock);
>
> ti_bandgap_power(bgp, true);
> + bgp->is_suspended = false;
>
> return ti_bandgap_restore_ctxt(bgp);
> }
> diff --git a/drivers/thermal/ti-soc-thermal/ti-bandgap.h b/drivers/thermal/ti-soc-thermal/ti-bandgap.h
> index fce4657e9486..ed0ea4b17b25 100644
> --- a/drivers/thermal/ti-soc-thermal/ti-bandgap.h
> +++ b/drivers/thermal/ti-soc-thermal/ti-bandgap.h
> @@ -12,6 +12,10 @@
> #include <linux/spinlock.h>
> #include <linux/types.h>
> #include <linux/err.h>
> +#include <linux/cpu_pm.h>
> +#include <linux/device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/pm.h>
>
> struct gpio_desc;
>
> @@ -203,6 +207,8 @@ struct ti_bandgap {
> int irq;
> struct gpio_desc *tshut_gpiod;
> u32 clk_rate;
> + struct notifier_block nb;
> + unsigned int is_suspended:1;
> };
>
> /**
