Mike Turquette <mturque...@ti.com> writes:
> Introduce notifier infrastructure for VDD voltage transitions. Users can
> register a notifier prior to a VDD's volt_scale function getting called
> (VOLTSCALE_PRECHANGE) or after the VDD has been scaled
> (VOLTSCALE_POSTCHANGE).
>
> Signed-off-by: Mike Turquette <mturque...@ti.com>
> ---
> All patches in this series based on PM branch (b6fb54b) plus Vishwa's 13
> OMAP3 DVFS patches (http://marc.info/?l=linux-omap&m=129561825804975&w=2).
> Only validated on Zoom3 since OMAP4 DVFS patches were not available.
>
> arch/arm/mach-omap2/voltage.c | 47
> ++++++++++++++++++++++++++++-
> arch/arm/plat-omap/include/plat/voltage.h | 30 ++++++++++++++++++
> 2 files changed, 76 insertions(+), 1 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/voltage.c b/arch/arm/mach-omap2/voltage.c
> index a0bd73b..0cbc58a 100644
> --- a/arch/arm/mach-omap2/voltage.c
> +++ b/arch/arm/mach-omap2/voltage.c
> @@ -729,6 +729,9 @@ static int __init omap3_vdd_data_configure(struct
> omap_vdd_info *vdd)
> return -EINVAL;
> }
>
> + /* initialize the voltage change notifier chain */
> + srcu_init_notifier_head(&vdd->volt_change_notify_chain);
> +
An explanation for the choice of SRCU notifiers would be useful.
Kevin
> if (!strcmp(vdd->voltdm.name, "mpu")) {
> if (cpu_is_omap3630()) {
> vdd->volt_data = omap36xx_vddmpu_volt_data;
> @@ -912,6 +915,9 @@ static int __init omap4_vdd_data_configure(struct
> omap_vdd_info *vdd)
> return -EINVAL;
> }
>
> + /* initialize the voltage change notifier chain */
> + srcu_init_notifier_head(&vdd->volt_change_notify_chain);
> +
> if (!strcmp(vdd->voltdm.name, "mpu")) {
> vdd->volt_data = omap44xx_vdd_mpu_volt_data;
> vdd->vp_reg.tranxdone_status =
> @@ -1201,7 +1207,9 @@ void omap_vp_disable(struct voltagedomain *voltdm)
> int omap_voltage_scale_vdd(struct voltagedomain *voltdm,
> unsigned long target_volt)
> {
> + int ret;
> struct omap_vdd_info *vdd;
> + struct omap_volt_change_info v_info;
>
> if (!voltdm || IS_ERR(voltdm)) {
> pr_warning("%s: VDD specified does not exist!\n", __func__);
> @@ -1216,7 +1224,20 @@ int omap_voltage_scale_vdd(struct voltagedomain
> *voltdm,
> return -ENODATA;
> }
>
> - return vdd->volt_scale(vdd, target_volt);
> + /* load notifier chain data */
> + v_info.target_volt = target_volt;
> + v_info.vdd = vdd;
> +
> + srcu_notifier_call_chain(&vdd->volt_change_notify_chain,
> + VOLTSCALE_PRECHANGE, (void *)&v_info);
> +
> + ret = vdd->volt_scale(vdd, target_volt);
> +
> + if (!ret)
> + srcu_notifier_call_chain(&vdd->volt_change_notify_chain,
> + VOLTSCALE_POSTCHANGE, (void *)&v_info);
> +
> + return ret;
> }
>
> /**
> @@ -1437,6 +1458,30 @@ struct voltagedomain *omap_voltage_domain_lookup(char
> *name)
> return ERR_PTR(-EINVAL);
> }
>
> +int omap_voltage_register_notifier(struct omap_vdd_info *vdd,
> + struct notifier_block *nb)
> +{
> + if (!vdd || IS_ERR(vdd)) {
> + pr_warning("%s: invalid VDD specified\n", __func__);
> + return -EINVAL;
> + }
> +
> + return srcu_notifier_chain_register(&vdd->volt_change_notify_chain,
> + nb);
> +}
> +
> +int omap_voltage_unregister_notifier(struct omap_vdd_info *vdd,
> + struct notifier_block *nb)
> +{
> + if (!vdd || IS_ERR(vdd)) {
> + pr_warning("%s: invalid VDD specified\n", __func__);
> + return -EINVAL;
> + }
> +
> + return srcu_notifier_chain_unregister(&vdd->volt_change_notify_chain,
> + nb);
> +}
> +
> /**
> * omap_voltage_late_init() - Init the various voltage parameters
> *
> diff --git a/arch/arm/plat-omap/include/plat/voltage.h
> b/arch/arm/plat-omap/include/plat/voltage.h
> index e0b7f22..017e65b 100644
> --- a/arch/arm/plat-omap/include/plat/voltage.h
> +++ b/arch/arm/plat-omap/include/plat/voltage.h
> @@ -15,10 +15,14 @@
> #define __ARCH_ARM_MACH_OMAP2_VOLTAGE_H
>
> #include <linux/err.h>
> +#include <linux/notifier.h>
>
> #define VOLTSCALE_VPFORCEUPDATE 1
> #define VOLTSCALE_VCBYPASS 2
>
> +#define VOLTSCALE_PRECHANGE 0
> +#define VOLTSCALE_POSTCHANGE 1
> +
> /*
> * OMAP3 GENERIC setup times. Revisit to see if these needs to be
> * passed from board or PMIC file
> @@ -249,6 +253,7 @@ struct omap_vdd_info {
> struct vc_reg_info vc_reg;
> struct voltagedomain voltdm;
> struct omap_vdd_dep_info *dep_vdd_info;
> + struct srcu_notifier_head volt_change_notify_chain;
> int nr_dep_vdd;
> struct dentry *debug_dir;
> u32 curr_volt;
> @@ -261,6 +266,17 @@ struct omap_vdd_info {
> unsigned long target_volt);
> };
>
> +/**
> + * omap_volt_change_info - container used by voltage notifier chain
> + *
> + * @vdd_info : the voltage domain affected by the transition
> + * @target_volt : voltage the affected domain is transitioning
> to
> + */
> +struct omap_volt_change_info {
> + unsigned long target_volt;
> + struct omap_vdd_info *vdd;
> +};
> +
> unsigned long omap_vp_get_curr_volt(struct voltagedomain *voltdm);
> void omap_vp_enable(struct voltagedomain *voltdm);
> void omap_vp_disable(struct voltagedomain *voltdm);
> @@ -280,6 +296,10 @@ void omap_change_voltscale_method(struct voltagedomain
> *voltdm,
> int voltscale_method);
> /* API to get the voltagedomain pointer */
> struct voltagedomain *omap_voltage_domain_lookup(char *name);
> +int omap_voltage_register_notifier(struct omap_vdd_info *vdd,
> + struct notifier_block *nb);
> +int omap_voltage_unregister_notifier(struct omap_vdd_info *vdd,
> + struct notifier_block *nb);
>
> int omap_voltage_late_init(void);
> #else
> @@ -298,6 +318,16 @@ static inline struct voltagedomain
> *omap_voltage_domain_lookup(char *name)
> {
> return ERR_PTR(-EINVAL);
> }
> +static inline int omap_voltage_register_notifier(struct omap_vdd_info *vdd,
> + struct notifier block *nb)
> +{
> + return 0;
> +}
> +static inline int omap_voltage_unregister_notifier(struct omap_vdd_info *vdd,
> + struct notifier block *nb)
> +{
> + return 0;
> +}
> #endif
>
> #endif
--
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