Re: [PATCH 2/8] ARM: OMAP2+: PM: introduce power domains functional states

["Menon, Nishanth" <nm@ti.com>]

On Thu, Jun 14, 2012 at 9:53 AM, Jean Pihet <jean.pihet@newoldbits.com> wrote:
[..]
> --- a/arch/arm/mach-omap2/powerdomain-common.c
> +++ b/arch/arm/mach-omap2/powerdomain-common.c
> @@ -108,3 +108,74 @@ u32 omap2_pwrdm_get_mem_bank_stst_mask(u8 bank)
>         return 0;
>  }
>
> +/**
> + * omap2_pwrdm_func_to_pwrst - Convert functional (i.e. logical) to
> + * internal (i.e. registers) values for the power domains states.
> + * @struct powerdomain * to convert the values for
> + * @func_pwrst: functional power state
> + *
> + * Returns the internal power state value for the power domain, or
> + * -EINVAL in case of invalid parameters passed in.
> + */
> +int omap2_pwrdm_func_to_pwrst(struct powerdomain *pwrdm, u8 func_pwrst)

Unless we handle logicpwst and pwst here, it makes it hard for non
arch/arm/mach-omap2/powerdomain* files to use this properly.

> +{
> +       int ret;
> +
> +       switch (func_pwrst) {
> +       case PWRDM_FUNC_PWRST_ON:
> +               ret = PWRDM_POWER_ON;
> +               break;
> +       case PWRDM_FUNC_PWRST_INACTIVE:
> +               ret = PWRDM_POWER_INACTIVE;
> +               break;
> +       case PWRDM_FUNC_PWRST_CSWR:
> +       case PWRDM_FUNC_PWRST_OSWR:
> +               ret = PWRDM_POWER_RET;

logic power state?

> +               break;
> +       case PWRDM_FUNC_PWRST_OFF:
> +               ret = PWRDM_POWER_OFF;
> +               break;
> +       default:
> +               ret = -EINVAL;
> +       }
> +
> +       return ret;
> +}
> +
> +/**
> + * omap2_pwrdm_pwrst_to_func - Convert internal (i.e. registers) to
> + * functional (i.e. logical) values for the power domains states.
> + * @struct powerdomain * to convert the values for
> + * @pwrst: internal power state
> + *
> + * Returns the functional power state value for the power domain, or
> + * -EINVAL in case of invalid parameters passed in.
> + */
> +int omap2_pwrdm_pwrst_to_func(struct powerdomain *pwrdm, u8 pwrst)
Same here as well..
> +{
> +       int ret;
> +
> +       switch (pwrst) {
> +       case PWRDM_POWER_ON:
> +               ret = PWRDM_FUNC_PWRST_ON;
> +               break;
> +       case PWRDM_POWER_INACTIVE:
> +               ret = PWRDM_FUNC_PWRST_INACTIVE;
> +               break;
> +       case PWRDM_POWER_RET:
> +               /*
> +                * XXX warning: return OSWR in case of pd in RET and
> +                * logic in OFF
> +                */
We need to be able to pass in logic pwst to be able to make that determination.

> +               ret = PWRDM_FUNC_PWRST_CSWR;
> +               break;
> +       case PWRDM_POWER_OFF:
> +               ret = PWRDM_FUNC_PWRST_OFF;
> +               break;
> +       default:
> +               ret = -EINVAL;
> +       }
> +
> +       return ret;
> +}
> +
> diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c
> index 1641e72..e79b5ae 100644
> --- a/arch/arm/mach-omap2/powerdomain.c
> +++ b/arch/arm/mach-omap2/powerdomain.c
> @@ -466,6 +466,135 @@ int pwrdm_get_mem_bank_count(struct powerdomain *pwrdm)
>  }
>
>  /**
> + * pwrdm_func_to_pwrst - get the internal (i.e. registers) value mapped
> + * to the functional state
> + * @pwrdm: struct powerdomain * to query
> + * @func_pwrst: functional power state
> + *
> + * Convert the functional power state to the platform specific power
> + * domain state value.
> + * Returns the internal power domain state value or -EINVAL in case
> + * of invalid parameters passed in.
> + */
> +int pwrdm_func_to_pwrst(struct powerdomain *pwrdm, u8 func_pwrst)
should take enum pwrdm_func_state func_pwrst

> +{
> +       int ret = func_pwrst;
> +
> +       if ((!pwrdm) || (func_pwrst >= PWRDM_MAX_FUNC_PWRSTS))
> +               return -EINVAL;
> +
> +       if (arch_pwrdm && arch_pwrdm->pwrdm_func_to_pwrst)
> +               ret = arch_pwrdm->pwrdm_func_to_pwrst(pwrdm, func_pwrst);

Should we not return an error if the function pointer is not available
for the arch?
on platforms without func_pwrst pointer converter routing hooked on,
we return func_pwrst back to caller, which expects pwrst!

> +
> +       pr_debug("powerdomain: convert func %0x to pwrst %0x for %s\n",
> +                func_pwrst, ret, pwrdm->name);
> +
> +       return ret;
> +}
> +
> +/**
> + * pwrdm_pwrst_to_func - get the functional (i.e. logical) value mapped
> + * to the internal state
> + * @pwrdm: struct powerdomain * to query
> + * @pwrst: internal power state
> + *
> + * Convert the internal power state to the power domain functional value.
> + * Returns the functional power domain state value or -EINVAL in case
> + * of invalid parameters passed in.
> + */
> +int pwrdm_pwrst_to_func(struct powerdomain *pwrdm, u8 pwrst)
should return enum pwrdm_func_state

> +{
> +       int ret = pwrst;
> +
> +       if ((!pwrdm) || (pwrst >= PWRDM_MAX_PWRSTS))
> +               return -EINVAL;
> +
> +       pr_debug("powerdomain: convert %0x pwrst to func for %s\n",
> +                pwrst, pwrdm->name);
> +
> +       if (arch_pwrdm && arch_pwrdm->pwrdm_pwrst_to_func)
> +               ret = arch_pwrdm->pwrdm_pwrst_to_func(pwrdm, pwrst);

same in reverse here.

> +
> +       return ret;
> +}
> +
> +/* Types of sleep_switch used in omap_set_pwrdm_state */
> +#define FORCEWAKEUP_SWITCH     0
> +#define LOWPOWERSTATE_SWITCH   1
> +
> +/**
> + * omap_set_pwrdm_state - program next powerdomain power state
> + * @pwrdm: struct powerdomain * to set
> + * @func_pwrst: power domain functional state, one of the PWRDM_FUNC_* macros
> + *
> + * This programs the pwrdm next functional state, sets the dependencies
> + * and waits for the state to be applied.
> + */
> +int omap_set_pwrdm_state(struct powerdomain *pwrdm,
> +                        enum pwrdm_func_state func_pwrst)
> +{
> +       u8 curr_pwrst, next_pwrst;
> +       int pwrst = pwrdm_func_to_pwrst(pwrdm, func_pwrst);
> +       int sleep_switch = -1, ret = 0, hwsup = 0;
> +
> +       if (!pwrdm || IS_ERR(pwrdm) || (pwrst < 0)) {
> +               pr_debug("%s: invalid params: pwrdm=%p, func_pwrst=%0x\n",
> +                        __func__, pwrdm, func_pwrst);
> +               return -EINVAL;
> +       }
> +
> +       pr_debug("%s: set func_pwrst %0x to pwrdm %s\n",
> +                __func__, func_pwrst, pwrdm->name);
> +
> +       mutex_lock(&pwrdm->lock);
This should be  a spinlock (previous patch i believe) - hurts cpuidle otherwise.

> +
> +       while (!(pwrdm->pwrsts & (1 << pwrst))) {
> +               if (pwrst == PWRDM_POWER_OFF)
> +                       goto out;
> +               pwrst--;
> +       }
> +

if we like to handle a single API for OSWR and CSWR, then it needs to
handle logic power state as well here.

> +       next_pwrst = pwrdm_read_next_pwrst(pwrdm);
> +       if (next_pwrst == pwrst)
> +               goto out;
> +
> +       curr_pwrst = pwrdm_read_pwrst(pwrdm);
> +       if (curr_pwrst < PWRDM_POWER_ON) {
> +               if ((curr_pwrst > pwrst) &&
> +                       (pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE)) {
> +                       sleep_switch = LOWPOWERSTATE_SWITCH;
> +               } else {
> +                       hwsup = clkdm_in_hwsup(pwrdm->pwrdm_clkdms[0]);
> +                       clkdm_wakeup(pwrdm->pwrdm_clkdms[0]);
> +                       sleep_switch = FORCEWAKEUP_SWITCH;
> +               }
> +       }
> +
> +       ret = pwrdm_set_next_pwrst(pwrdm, pwrst);
> +       if (ret)
> +               pr_err("%s: unable to set power state of powerdomain: %s\n",
> +                      __func__, pwrdm->name);
> +
> +       switch (sleep_switch) {
> +       case FORCEWAKEUP_SWITCH:
> +               if (hwsup)
> +                       clkdm_allow_idle(pwrdm->pwrdm_clkdms[0]);
> +               else
> +                       clkdm_sleep(pwrdm->pwrdm_clkdms[0]);
> +               break;
> +       case LOWPOWERSTATE_SWITCH:
> +               pwrdm_set_lowpwrstchange(pwrdm);
> +               pwrdm_wait_transition(pwrdm);
> +               pwrdm_state_switch(pwrdm);
> +               break;
> +       }
> +
> +out:
> +       mutex_unlock(&pwrdm->lock);
> +       return ret;
> +}
> +
> +/**
>   * pwrdm_set_next_pwrst - set next powerdomain power state
>   * @pwrdm: struct powerdomain * to set
>   * @pwrst: one of the PWRDM_POWER_* macros
> @@ -522,6 +651,21 @@ int pwrdm_read_next_pwrst(struct powerdomain *pwrdm)
>  }
>
>  /**
> + * pwrdm_read_next_func_pwrst - get next powerdomain functional power state
> + * @pwrdm: struct powerdomain * to get power state
> + *
> + * Return the powerdomain @pwrdm's next functional power state.
> + * Returns -EINVAL if the powerdomain pointer is null or returns
> + * the next power state upon success.
> + */
> +int pwrdm_read_next_func_pwrst(struct powerdomain *pwrdm)
should return enum pwrdm_func_state
> +{
> +       int ret = pwrdm_read_next_pwrst(pwrdm);
> +
> +       return pwrdm_pwrst_to_func(pwrdm, ret);
> +}
> +
> +/**
>   * pwrdm_read_pwrst - get current powerdomain power state
>   * @pwrdm: struct powerdomain * to get power state
>   *
> @@ -543,6 +687,21 @@ int pwrdm_read_pwrst(struct powerdomain *pwrdm)
>  }
>
>  /**
> + * pwrdm_read_func_pwrst - get current powerdomain functional power state
> + * @pwrdm: struct powerdomain * to get power state
> + *
> + * Return the powerdomain @pwrdm's current functional power state.
> + * Returns -EINVAL if the powerdomain pointer is null or returns
> + * the current power state upon success.
> + */
> +int pwrdm_read_func_pwrst(struct powerdomain *pwrdm)
should return enum pwrdm_func_state
> +{
> +       int ret = pwrdm_read_pwrst(pwrdm);
> +
> +       return pwrdm_pwrst_to_func(pwrdm, ret);
> +}

my Crib about the above apis are lack of logic power state handling :(
which forces code like cpuidle to use different apis for logic
power state and force them to use these apis just for pwrst.


> +
> +/**
>   * pwrdm_read_prev_pwrst - get previous powerdomain power state
>   * @pwrdm: struct powerdomain * to get previous power state
>   *
> @@ -564,6 +723,21 @@ int pwrdm_read_prev_pwrst(struct powerdomain *pwrdm)
>  }
>
>  /**
> + * pwrdm_read_prev_func_pwrst - get previous powerdomain functional power state
> + * @pwrdm: struct powerdomain * to get previous power state
> + *
> + * Return the powerdomain @pwrdm's previous functional power state.
> + * Returns -EINVAL if the powerdomain pointer is null or returns the
> + * previous power state upon success.
> + */
> +int pwrdm_read_prev_func_pwrst(struct powerdomain *pwrdm)
should return enum pwrdm_func_state
> +{
> +       int ret = pwrdm_read_prev_pwrst(pwrdm);
> +
> +       return pwrdm_pwrst_to_func(pwrdm, ret);
> +}
again here.

> +
> +/**
>   * pwrdm_set_logic_retst - set powerdomain logic power state upon retention
>   * @pwrdm: struct powerdomain * to set
>   * @pwrst: one of the PWRDM_POWER_* macros
> diff --git a/arch/arm/mach-omap2/powerdomain.h b/arch/arm/mach-omap2/powerdomain.h
> index bab84fc..0404f9f 100644
> --- a/arch/arm/mach-omap2/powerdomain.h
> +++ b/arch/arm/mach-omap2/powerdomain.h
> @@ -9,9 +9,6 @@
>   * This program is free software; you can redistribute it and/or modify
>   * it under the terms of the GNU General Public License version 2 as
>   * published by the Free Software Foundation.
> - *
> - * XXX This should be moved to the mach-omap2/ directory at the earliest
> - * opportunity.
>   */
>
>  #ifndef __ARCH_ARM_MACH_OMAP2_POWERDOMAIN_H
> @@ -26,7 +23,51 @@
>
>  #include "voltage.h"
>
> -/* Powerdomain basic power states */
> +/***************************************************************
> + * External API
> + ***************************************************************/
> +
> +/* Powerdomain functional power states, used by the external API functions */
> +enum pwrdm_func_state {
> +       PWRDM_FUNC_PWRST_OFF            = 0x0,
> +       PWRDM_FUNC_PWRST_OSWR,
> +       PWRDM_FUNC_PWRST_CSWR,
> +       PWRDM_FUNC_PWRST_INACTIVE,
> +       PWRDM_FUNC_PWRST_ON,
> +       PWRDM_MAX_FUNC_PWRSTS           /* Last value, used as the max value */
> +};
> +
> +struct clockdomain;
> +struct powerdomain;
> +
> +struct powerdomain *pwrdm_lookup(const char *name);
> +
> +int pwrdm_for_each(int (*fn)(struct powerdomain *pwrdm, void *user),
> +                       void *user);
> +int pwrdm_for_each_nolock(int (*fn)(struct powerdomain *pwrdm, void *user),
> +                       void *user);
> +
> +struct voltagedomain *pwrdm_get_voltdm(struct powerdomain *pwrdm);
> +
> +int pwrdm_get_mem_bank_count(struct powerdomain *pwrdm);
> +
> +int pwrdm_read_prev_func_pwrst(struct powerdomain *pwrdm);
> +int pwrdm_read_func_pwrst(struct powerdomain *pwrdm);
> +int pwrdm_read_next_func_pwrst(struct powerdomain *pwrdm);
> +extern int omap_set_pwrdm_state(struct powerdomain *pwrdm,
> +                               enum pwrdm_func_state func_pwrst);
> +
> +extern void omap242x_powerdomains_init(void);
> +extern void omap243x_powerdomains_init(void);
> +extern void omap3xxx_powerdomains_init(void);
> +extern void omap44xx_powerdomains_init(void);
> +
> +

We should split the following out to a separate header which is not to
be used by anyone else other than powerdomain*.[ch]

> +/***************************************************************
> + * Internal code, only used in powerdomain*.[ch]
> + ***************************************************************/
> +
> +/* Powerdomain internal power states, internal use only */
>  #define PWRDM_POWER_OFF                0x0
>  #define PWRDM_POWER_RET                0x1
>  #define PWRDM_POWER_INACTIVE   0x2
> @@ -45,7 +86,6 @@
>  #define PWRSTS_RET_ON          (PWRSTS_RET | PWRSTS_ON)
>  #define PWRSTS_OFF_RET_ON      (PWRSTS_OFF_RET | PWRSTS_ON)
>
> -
>  /* Powerdomain flags */
>  #define PWRDM_HAS_HDWR_SAR     (1 << 0) /* hardware save-and-restore support */
>  #define PWRDM_HAS_MPU_QUIRK    (1 << 1) /* MPU pwr domain has MEM bank 0 bits
> @@ -74,9 +114,6 @@
>  /* XXX A completely arbitrary number. What is reasonable here? */
>  #define PWRDM_TRANSITION_BAILOUT 100000
>
> -struct clockdomain;
> -struct powerdomain;
> -
>  /**
>   * struct powerdomain - OMAP powerdomain
>   * @name: Powerdomain name
> @@ -130,6 +167,10 @@ struct powerdomain {
>
>  /**
>   * struct pwrdm_ops - Arch specific function implementations
> + * @pwrdm_func_to_pwrst: Convert the pd functional power state to
> + *  the internal state
> + * @pwrdm_pwrst_to_func: Convert the pd internal power state to
> + *  the functional state
>   * @pwrdm_set_next_pwrst: Set the target power state for a pd
>   * @pwrdm_read_next_pwrst: Read the target power state set for a pd
>   * @pwrdm_read_pwrst: Read the current power state of a pd
> @@ -150,6 +191,8 @@ struct powerdomain {
>   * @pwrdm_wait_transition: Wait for a pd state transition to complete
>   */
>  struct pwrdm_ops {
> +       int     (*pwrdm_func_to_pwrst)(struct powerdomain *pwrdm, u8 func_pwrst);
should take in enum pwrdm_func_state
> +       int     (*pwrdm_pwrst_to_func)(struct powerdomain *pwrdm, u8 func_pwrst);
should return enum pwrdm_func_state

>         int     (*pwrdm_set_next_pwrst)(struct powerdomain *pwrdm, u8 pwrst);
>         int     (*pwrdm_read_next_pwrst)(struct powerdomain *pwrdm);
>         int     (*pwrdm_read_pwrst)(struct powerdomain *pwrdm);
> @@ -174,21 +217,11 @@ int pwrdm_register_platform_funcs(struct pwrdm_ops *custom_funcs);
>  int pwrdm_register_pwrdms(struct powerdomain **pwrdm_list);
>  int pwrdm_complete_init(void);
>
> -struct powerdomain *pwrdm_lookup(const char *name);
> -
> -int pwrdm_for_each(int (*fn)(struct powerdomain *pwrdm, void *user),
> -                       void *user);
> -int pwrdm_for_each_nolock(int (*fn)(struct powerdomain *pwrdm, void *user),
> -                       void *user);
> -
>  int pwrdm_add_clkdm(struct powerdomain *pwrdm, struct clockdomain *clkdm);
>  int pwrdm_del_clkdm(struct powerdomain *pwrdm, struct clockdomain *clkdm);
>  int pwrdm_for_each_clkdm(struct powerdomain *pwrdm,
>                          int (*fn)(struct powerdomain *pwrdm,
>                                    struct clockdomain *clkdm));
> -struct voltagedomain *pwrdm_get_voltdm(struct powerdomain *pwrdm);
> -
> -int pwrdm_get_mem_bank_count(struct powerdomain *pwrdm);
>
>  int pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst);
>  int pwrdm_read_next_pwrst(struct powerdomain *pwrdm);
> @@ -196,6 +229,9 @@ int pwrdm_read_pwrst(struct powerdomain *pwrdm);
>  int pwrdm_read_prev_pwrst(struct powerdomain *pwrdm);
>  int pwrdm_clear_all_prev_pwrst(struct powerdomain *pwrdm);
>
> +int omap2_pwrdm_func_to_pwrst(struct powerdomain *pwrdm, u8 func_pwrst);
> +int omap2_pwrdm_pwrst_to_func(struct powerdomain *pwrdm, u8 pwrst);
> +
>  int pwrdm_set_logic_retst(struct powerdomain *pwrdm, u8 pwrst);
>  int pwrdm_set_mem_onst(struct powerdomain *pwrdm, u8 bank, u8 pwrst);
>  int pwrdm_set_mem_retst(struct powerdomain *pwrdm, u8 bank, u8 pwrst);
> @@ -220,11 +256,6 @@ int pwrdm_set_lowpwrstchange(struct powerdomain *pwrdm);
>  int pwrdm_get_context_loss_count(struct powerdomain *pwrdm);
>  bool pwrdm_can_ever_lose_context(struct powerdomain *pwrdm);
>
> -extern void omap242x_powerdomains_init(void);
> -extern void omap243x_powerdomains_init(void);
> -extern void omap3xxx_powerdomains_init(void);
> -extern void omap44xx_powerdomains_init(void);
> -
>  extern struct pwrdm_ops omap2_pwrdm_operations;
>  extern struct pwrdm_ops omap3_pwrdm_operations;
>  extern struct pwrdm_ops omap4_pwrdm_operations;
> diff --git a/arch/arm/mach-omap2/powerdomain2xxx_3xxx.c b/arch/arm/mach-omap2/powerdomain2xxx_3xxx.c
> index 0f0a9f1..79c1293 100644
> --- a/arch/arm/mach-omap2/powerdomain2xxx_3xxx.c
> +++ b/arch/arm/mach-omap2/powerdomain2xxx_3xxx.c
> @@ -26,6 +26,7 @@
>
>
>  /* Common functions across OMAP2 and OMAP3 */
> +
>  static int omap2_pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst)
>  {
>         omap2_prm_rmw_mod_reg_bits(OMAP_POWERSTATE_MASK,
> @@ -210,6 +211,8 @@ static int omap3_pwrdm_disable_hdwr_sar(struct powerdomain *pwrdm)
>  }
>
>  struct pwrdm_ops omap2_pwrdm_operations = {
> +       .pwrdm_func_to_pwrst    = omap2_pwrdm_func_to_pwrst,
> +       .pwrdm_pwrst_to_func    = omap2_pwrdm_pwrst_to_func,
>         .pwrdm_set_next_pwrst   = omap2_pwrdm_set_next_pwrst,
>         .pwrdm_read_next_pwrst  = omap2_pwrdm_read_next_pwrst,
>         .pwrdm_read_pwrst       = omap2_pwrdm_read_pwrst,
> @@ -222,6 +225,8 @@ struct pwrdm_ops omap2_pwrdm_operations = {
>  };
>
>  struct pwrdm_ops omap3_pwrdm_operations = {
> +       .pwrdm_func_to_pwrst    = omap2_pwrdm_func_to_pwrst,
> +       .pwrdm_pwrst_to_func    = omap2_pwrdm_pwrst_to_func,
>         .pwrdm_set_next_pwrst   = omap2_pwrdm_set_next_pwrst,
>         .pwrdm_read_next_pwrst  = omap2_pwrdm_read_next_pwrst,
>         .pwrdm_read_pwrst       = omap2_pwrdm_read_pwrst,
> diff --git a/arch/arm/mach-omap2/powerdomain44xx.c b/arch/arm/mach-omap2/powerdomain44xx.c
> index 601325b..538b528 100644
> --- a/arch/arm/mach-omap2/powerdomain44xx.c
> +++ b/arch/arm/mach-omap2/powerdomain44xx.c
> @@ -209,6 +209,8 @@ static int omap4_pwrdm_wait_transition(struct powerdomain *pwrdm)
>  }
>
>  struct pwrdm_ops omap4_pwrdm_operations = {
> +       .pwrdm_func_to_pwrst    = omap2_pwrdm_func_to_pwrst,
> +       .pwrdm_pwrst_to_func    = omap2_pwrdm_pwrst_to_func,
>         .pwrdm_set_next_pwrst   = omap4_pwrdm_set_next_pwrst,
>         .pwrdm_read_next_pwrst  = omap4_pwrdm_read_next_pwrst,
>         .pwrdm_read_pwrst       = omap4_pwrdm_read_pwrst,

otherwise, this is a nice concept
--
Regards,
Nishanth Menon