[PATCH 1/7] ARM: OMAP2+: PM: introduce power domains functional states

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Introduce the functional states for power domains, which include
the power states and the logic states.
This patch provides the API functions to set and read the power
domains functional state and internal functions to convert between
the functional (i.e. logical) and the internal (or registers) values.

In the new API only the functions pwrdm_set_next_fpwrst and
pwrdm_set_next_fpwrst shall be used to change a power domain
target state, along with the associated PWRDM_FUNC_* and
PWRDM_LOGIC_* macros as the state parameters.

Note about the power domains allowed states:
Power domains have varied capabilities, as defined by the value of
the pwrsts and pwrsts_logic_ret fields of the powerdomain struct.
When reading or setting a low power state such as OFF/RET, a specific
requested state may not be supported on the given power domain.
In the states conversion functions a power or logic state is first
looked for in the lower power states in order to maximize the power
savings, then if not found in the higher power states. An iteration
function is used, as suggested by Rajendra Nayak <rnayak@xxxxxx>

This functionality brings consistency in the functional power states
core code and acts as a guard against hardware implementations
discrepancies, e.g. some power domains only support the RET logic
state although reading the logic state registers (previous, current
and next) always returns OFF. The DSS power domain on OMAP3 is an
example.

Signed-off-by: Jean Pihet <j-pihet@xxxxxx>
Cc: Tero Kristo <t-kristo@xxxxxx>
Cc: Rajendra Nayak <rnayak@xxxxxx>
Cc: Nishanth Menon <nm@xxxxxx>
---
 arch/arm/mach-omap2/powerdomain.c |  374 ++++++++++++++++++++++++++++++++++++-
 arch/arm/mach-omap2/powerdomain.h |   32 +++-
 2 files changed, 396 insertions(+), 10 deletions(-)

diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c
index 69b36e1..18c21fa 100644
--- a/arch/arm/mach-omap2/powerdomain.c
+++ b/arch/arm/mach-omap2/powerdomain.c
@@ -1,7 +1,7 @@
 /*
  * OMAP powerdomain control
  *
- * Copyright (C) 2007-2008, 2011 Texas Instruments, Inc.
+ * Copyright (C) 2007-2008, 2011-2012 Texas Instruments, Inc.
  * Copyright (C) 2007-2011 Nokia Corporation
  *
  * Written by Paul Walmsley
@@ -128,14 +128,14 @@ static void _update_logic_membank_counters(struct powerdomain *pwrdm)
 
 	prev_logic_pwrst = pwrdm_read_prev_logic_pwrst(pwrdm);
 	if ((pwrdm->pwrsts_logic_ret == PWRSTS_OFF_RET) &&
-	    (prev_logic_pwrst == PWRDM_POWER_OFF))
+	    (prev_logic_pwrst == PWRDM_LOGIC_MEM_PWRST_OFF))
 		pwrdm->ret_logic_off_counter++;
 
 	for (i = 0; i < pwrdm->banks; i++) {
 		prev_mem_pwrst = pwrdm_read_prev_mem_pwrst(pwrdm, i);
 
 		if ((pwrdm->pwrsts_mem_ret[i] == PWRSTS_OFF_RET) &&
-		    (prev_mem_pwrst == PWRDM_POWER_OFF))
+		    (prev_mem_pwrst == PWRDM_LOGIC_MEM_PWRST_OFF))
 			pwrdm->ret_mem_off_counter[i]++;
 	}
 }
@@ -199,6 +199,201 @@ static int _pwrdm_post_transition_cb(struct powerdomain *pwrdm, void *unused)
 	return 0;
 }
 
+/**
+ * Search down then up for a valid state from a list of allowed states.
+ * Used by states conversion functions (_pwrdm_fpwrst_to_*) to look for
+ * allowed power and logic states for a powerdomain.
+ *
+ * @pwrsts: list of allowed states, defined as a bitmask
+ * @pwrst: initial state to be used as a starting point
+ * @min: minimum (i.e. lowest consumption) allowed state
+ * @max: maximum (i.e. highest consumption) allowed state
+ *
+ * Returns the matching allowed state.
+ */
+static inline int _match_pwrst(u32 pwrsts, int pwrst, int min, int max)
+{
+	int found = 1, new_pwrst = pwrst;
+
+	/*
+	 * If the power domain does not allow any state programmation
+	 * return the max state which is always allowed
+	 */
+	if (!pwrsts)
+		return max;
+
+	/*
+	 * Search lower: if the requested state is not supported
+	 * try the lower states, stopping at the minimum allowed
+	 * state
+	 */
+	while (!(pwrsts & (1 << new_pwrst))) {
+		if (new_pwrst <= min) {
+			found = 0;
+			break;
+		}
+		new_pwrst--;
+	}
+
+	/*
+	 * Search higher: if no lower state found fallback to the higher
+	 * states, stopping at the maximum allowed state
+	 */
+	if (!found) {
+		new_pwrst = pwrst;
+		while (!(pwrsts & (1 << new_pwrst))) {
+			if (new_pwrst >= max) {
+				new_pwrst = max;
+				break;
+			}
+			new_pwrst++;
+		}
+	}
+
+	return new_pwrst;
+}
+
+/**
+ * _pwrdm_fpwrst_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
+ * @fpwrst: functional power state
+ *
+ * Returns the internal power state value for the power domain, or
+ * -EINVAL in case of invalid parameters passed in.
+ */
+static int _pwrdm_fpwrst_to_pwrst(struct powerdomain *pwrdm, u8 fpwrst)
+{
+	int ret;
+
+	if (!pwrdm) {
+		pr_err_ratelimited("%s: NULL pwrdm\n", __func__);
+		return -EINVAL;
+	}
+
+	switch (fpwrst) {
+	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;
+		break;
+	case PWRDM_FUNC_PWRST_OFF:
+		ret = PWRDM_POWER_OFF;
+		break;
+	default:
+		pr_err_ratelimited("%s: powerdomain %s: bad fpwrst %0x\n",
+				   __func__, pwrdm->name, fpwrst);
+		return -EINVAL;
+	}
+
+	ret = _match_pwrst(pwrdm->pwrsts, ret,
+			   PWRDM_POWER_OFF,
+			   PWRDM_POWER_ON);
+
+	pr_debug("powerdomain %s: convert fpwrst %0x to pwrst %0x\n",
+		 pwrdm->name, fpwrst, ret);
+
+	return ret;
+}
+
+/**
+ * _pwrdm_fpwrst_to_logic_pwrst - Convert functional (i.e. logical) to
+ * internal (i.e. registers) values for the power domains logic states.
+ * @struct powerdomain * to convert the values for
+ * @pwrst: functional power state
+ *
+ * Returns the internal logic state value for the power domain, or
+ * -EINVAL in case of invalid parameters passed in.
+ */
+static int _pwrdm_fpwrst_to_logic_pwrst(struct powerdomain *pwrdm, u8 fpwrst)
+{
+	int ret;
+
+	if (!pwrdm) {
+		pr_err_ratelimited("%s: NULL pwrdm\n", __func__);
+		return -EINVAL;
+	}
+
+	switch (fpwrst) {
+	case PWRDM_FUNC_PWRST_ON:
+	case PWRDM_FUNC_PWRST_INACTIVE:
+	case PWRDM_FUNC_PWRST_CSWR:
+		ret = PWRDM_LOGIC_MEM_PWRST_RET;
+		break;
+	case PWRDM_FUNC_PWRST_OSWR:
+	case PWRDM_FUNC_PWRST_OFF:
+		ret = PWRDM_LOGIC_MEM_PWRST_OFF;
+		break;
+	default:
+		pr_err_ratelimited("%s: powerdomain %s: bad fpwrst %0x\n",
+				   __func__, pwrdm->name, fpwrst);
+		return -EINVAL;
+	}
+
+	ret = _match_pwrst(pwrdm->pwrsts_logic_ret, ret,
+			   PWRDM_LOGIC_MEM_PWRST_OFF,
+			   PWRDM_LOGIC_MEM_PWRST_RET);
+
+	pr_debug("powerdomain %s: convert fpwrst %0x to logic %0x pwrst\n",
+		 pwrdm->name, fpwrst, ret);
+
+	return ret;
+}
+
+/**
+ * _pwrdm_pwrst_to_fpwrst - 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.
+ */
+static int _pwrdm_pwrst_to_fpwrst(struct powerdomain *pwrdm, u8 pwrst, u8 logic)
+{
+	int ret;
+
+	if (!pwrdm) {
+		pr_err_ratelimited("%s: NULL pwrdm\n", __func__);
+		return -EINVAL;
+	}
+
+	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:
+		logic = _match_pwrst(pwrdm->pwrsts_logic_ret, logic,
+				     PWRDM_LOGIC_MEM_PWRST_OFF,
+				     PWRDM_LOGIC_MEM_PWRST_RET);
+
+		if (logic == PWRDM_LOGIC_MEM_PWRST_OFF)
+			ret = PWRDM_FUNC_PWRST_OSWR;
+		else
+			ret = PWRDM_FUNC_PWRST_CSWR;
+		break;
+	case PWRDM_POWER_OFF:
+		ret = PWRDM_FUNC_PWRST_OFF;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	pr_debug("powerdomain: convert pwrst (%0x,%0x) to fpwrst %0x\n",
+		 pwrst, logic, ret);
+
+	return ret;
+}
+
+
 /* Public functions */
 
 /**
@@ -464,6 +659,111 @@ int pwrdm_get_mem_bank_count(struct powerdomain *pwrdm)
 	return pwrdm->banks;
 }
 
+/* Types of sleep_switch used in pwrdm_set_fpwrst */
+#define FORCEWAKEUP_SWITCH	0
+#define LOWPOWERSTATE_SWITCH	1
+
+/**
+ * pwrdm_set_fpwrst - program next powerdomain functional power state
+ * @pwrdm: struct powerdomain * to set
+ * @fpwrst: 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 pwrdm_set_fpwrst(struct powerdomain *pwrdm, enum pwrdm_func_state fpwrst)
+{
+	u8 curr_pwrst, next_fpwrst;
+	int pwrst = _pwrdm_fpwrst_to_pwrst(pwrdm, fpwrst);
+	int logic = _pwrdm_fpwrst_to_logic_pwrst(pwrdm, fpwrst);
+	int sleep_switch = -1, ret = 0, hwsup = 0;
+
+	if (!pwrdm || IS_ERR(pwrdm) || (pwrst < 0) || (logic < 0)) {
+		pr_debug("%s: invalid params: pwrdm=%p, fpwrst=%0x\n",
+			 __func__, pwrdm, fpwrst);
+		return -EINVAL;
+	}
+
+	pr_debug("%s: set fpwrst %0x to pwrdm %s\n",
+		 __func__, fpwrst, pwrdm->name);
+
+	next_fpwrst = pwrdm_read_next_fpwrst(pwrdm);
+	if (next_fpwrst == fpwrst)
+		return ret;
+
+	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;
+		}
+	}
+
+	if (logic != pwrdm_read_logic_retst(pwrdm))
+		pwrdm_set_logic_retst(pwrdm, logic);
+
+	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;
+	}
+
+	return ret;
+}
+
+/**
+ * pwrdm_set_next_fpwrst - set next powerdomain functional power state
+ * @pwrdm: struct powerdomain * to set
+ * @fpwrst: power domain functional state, one of the PWRDM_FUNC_* macros
+ *
+ * This programs the pwrdm next functional state
+ */
+int pwrdm_set_next_fpwrst(struct powerdomain *pwrdm,
+			  enum pwrdm_func_state fpwrst)
+{
+	int pwrst = _pwrdm_fpwrst_to_pwrst(pwrdm, fpwrst);
+	int logic = _pwrdm_fpwrst_to_logic_pwrst(pwrdm, fpwrst);
+	int ret = 0;
+
+	if (!pwrdm || IS_ERR(pwrdm) || (pwrst < 0) || (logic < 0)) {
+		pr_debug("%s: invalid params: pwrdm=%p, fpwrst=%0x\n",
+			 __func__, pwrdm, fpwrst);
+		return -EINVAL;
+	}
+
+	pr_debug("%s: set fpwrst %0x to pwrdm %s\n",
+		 __func__, fpwrst, pwrdm->name);
+
+	ret = pwrdm_set_logic_retst(pwrdm, logic);
+	if (ret)
+		pr_err("%s: unable to set logic state %0x of powerdomain: %s\n",
+		       __func__, logic, pwrdm->name);
+
+	ret = pwrdm_set_next_pwrst(pwrdm, pwrst);
+	if (ret)
+		pr_err("%s: unable to set power state %0x of powerdomain: %s\n",
+		       __func__, pwrst, pwrdm->name);
+
+	return ret;
+};
+
 /**
  * pwrdm_set_next_pwrst - set next powerdomain power state
  * @pwrdm: struct powerdomain * to set
@@ -482,6 +782,13 @@ int pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst)
 	if (!pwrdm)
 		return -EINVAL;
 
+	/*
+	 * Do nothing in case the power domain does not have any
+	 * valid state, e.g. DPLL domains.
+	 */
+	if (!pwrdm->pwrsts)
+		return 0;
+
 	if (!(pwrdm->pwrsts & (1 << pwrst)))
 		return -EINVAL;
 
@@ -521,6 +828,22 @@ int pwrdm_read_next_pwrst(struct powerdomain *pwrdm)
 }
 
 /**
+ * pwrdm_read_next_fpwrst - 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_fpwrst(struct powerdomain *pwrdm)
+{
+	int next_pwrst = pwrdm_read_next_pwrst(pwrdm);
+	int next_logic = pwrdm_read_logic_retst(pwrdm);
+
+	return _pwrdm_pwrst_to_fpwrst(pwrdm, next_pwrst, next_logic);
+}
+
+/**
  * pwrdm_read_pwrst - get current powerdomain power state
  * @pwrdm: struct powerdomain * to get power state
  *
@@ -546,6 +869,22 @@ int pwrdm_read_pwrst(struct powerdomain *pwrdm)
 }
 
 /**
+ * pwrdm_read_fpwrst - 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_fpwrst(struct powerdomain *pwrdm)
+{
+	int pwrst = pwrdm_read_pwrst(pwrdm);
+	int logic = pwrdm_read_logic_pwrst(pwrdm);
+
+	return _pwrdm_pwrst_to_fpwrst(pwrdm, pwrst, logic);
+}
+
+/**
  * pwrdm_read_prev_pwrst - get previous powerdomain power state
  * @pwrdm: struct powerdomain * to get previous power state
  *
@@ -567,9 +906,25 @@ int pwrdm_read_prev_pwrst(struct powerdomain *pwrdm)
 }
 
 /**
+ * pwrdm_read_prev_fpwrst - 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_fpwrst(struct powerdomain *pwrdm)
+{
+	int prev_pwrst = pwrdm_read_prev_pwrst(pwrdm);
+	int prev_logic = pwrdm_read_prev_logic_pwrst(pwrdm);
+
+	return _pwrdm_pwrst_to_fpwrst(pwrdm, prev_pwrst, prev_logic);
+}
+
+/**
  * pwrdm_set_logic_retst - set powerdomain logic power state upon retention
  * @pwrdm: struct powerdomain * to set
- * @pwrst: one of the PWRDM_POWER_* macros
+ * @pwrst: one of the PWRDM_LOGIC_MEM_PWRST_* macros
  *
  * Set the next power state @pwrst that the logic portion of the
  * powerdomain @pwrdm will enter when the powerdomain enters retention.
@@ -584,6 +939,13 @@ int pwrdm_set_logic_retst(struct powerdomain *pwrdm, u8 pwrst)
 	if (!pwrdm)
 		return -EINVAL;
 
+	/*
+	 * Do nothing in case the power domain does not have any
+	 * valid state, e.g. DPLL domains.
+	 */
+	if (!pwrdm->pwrsts_logic_ret)
+		return 0;
+
 	if (!(pwrdm->pwrsts_logic_ret & (1 << pwrst)))
 		return -EINVAL;
 
@@ -600,7 +962,7 @@ int pwrdm_set_logic_retst(struct powerdomain *pwrdm, u8 pwrst)
  * pwrdm_set_mem_onst - set memory power state while powerdomain ON
  * @pwrdm: struct powerdomain * to set
  * @bank: memory bank number to set (0-3)
- * @pwrst: one of the PWRDM_POWER_* macros
+ * @pwrst: one of the PWRDM_LOGIC_MEM_PWRST_* macros
  *
  * Set the next power state @pwrst that memory bank @bank of the
  * powerdomain @pwrdm will enter when the powerdomain enters the ON
@@ -637,7 +999,7 @@ int pwrdm_set_mem_onst(struct powerdomain *pwrdm, u8 bank, u8 pwrst)
  * pwrdm_set_mem_retst - set memory power state while powerdomain in RET
  * @pwrdm: struct powerdomain * to set
  * @bank: memory bank number to set (0-3)
- * @pwrst: one of the PWRDM_POWER_* macros
+ * @pwrst: one of the PWRDM_LOGIC_MEM_PWRST_* macros
  *
  * Set the next power state @pwrst that memory bank @bank of the
  * powerdomain @pwrdm will enter when the powerdomain enters the
diff --git a/arch/arm/mach-omap2/powerdomain.h b/arch/arm/mach-omap2/powerdomain.h
index baee906..aa5de4f 100644
--- a/arch/arm/mach-omap2/powerdomain.h
+++ b/arch/arm/mach-omap2/powerdomain.h
@@ -1,7 +1,7 @@
 /*
  * OMAP2/3/4 powerdomain control
  *
- * Copyright (C) 2007-2008, 2010 Texas Instruments, Inc.
+ * Copyright (C) 2007-2008, 2010, 2012 Texas Instruments, Inc.
  * Copyright (C) 2007-2011 Nokia Corporation
  *
  * Paul Walmsley
@@ -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
@@ -26,6 +23,26 @@
 
 #include "voltage.h"
 
+/* 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 */
+};
+
+/*
+ * Powerdomains logic and memory functional power states,
+ * used by the external API functions
+ */
+enum pwrdm_logic_mem_state {
+	PWRDM_LOGIC_MEM_PWRST_OFF	= 0x0,
+	PWRDM_LOGIC_MEM_PWRST_RET,
+	PWRDM_MAX_LOGIC_MEM_PWRST	/* Last value, used as the max value */
+};
+
 /* Powerdomain basic power states */
 #define PWRDM_POWER_OFF		0x0
 #define PWRDM_POWER_RET		0x1
@@ -206,6 +223,13 @@ struct voltagedomain *pwrdm_get_voltdm(struct powerdomain *pwrdm);
 
 int pwrdm_get_mem_bank_count(struct powerdomain *pwrdm);
 
+int pwrdm_set_fpwrst(struct powerdomain *pwrdm, enum pwrdm_func_state fpwrst);
+int pwrdm_set_next_fpwrst(struct powerdomain *pwrdm,
+			  enum pwrdm_func_state fpwrst);
+int pwrdm_read_prev_fpwrst(struct powerdomain *pwrdm);
+int pwrdm_read_fpwrst(struct powerdomain *pwrdm);
+int pwrdm_read_next_fpwrst(struct powerdomain *pwrdm);
+
 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);
-- 
1.7.7.6

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