rt-patches/0257-Revert-ARM-OMAP2-Drop-the-concept-of-certain-power-d.patch

From c0d9c3ff64de9f40e29b5f00aabc4d3ffd2c9175 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 13 Jan 2016 17:43:57 +0100
Subject: [PATCH 257/351] Revert "ARM: OMAP2: Drop the concept of certain power
 domains not being able to lose context."
X-NVConfidentiality: public

Requested by Grygorii Strashko <grygorii.strashko@ti.com>, not required
for v4.4-RT

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 arch/arm/mach-omap2/gpio.c              |  1 +
 arch/arm/mach-omap2/powerdomain.c       | 40 +++++++++++++++++++++++++++++++++
 arch/arm/mach-omap2/powerdomain.h       |  1 +
 drivers/gpio/gpio-omap.c                | 36 +++++++++++++++++------------
 include/linux/platform_data/gpio-omap.h |  1 +
 5 files changed, 65 insertions(+), 14 deletions(-)

diff --git a/arch/arm/mach-omap2/gpio.c b/arch/arm/mach-omap2/gpio.c
index 689a1af47c80..7a577145b68b 100644
--- a/arch/arm/mach-omap2/gpio.c
+++ b/arch/arm/mach-omap2/gpio.c
@@ -130,6 +130,7 @@ static int __init omap2_gpio_dev_init(struct omap_hwmod *oh, void *unused)
 	}
 
 	pwrdm = omap_hwmod_get_pwrdm(oh);
+	pdata->loses_context = pwrdm_can_ever_lose_context(pwrdm);
 
 	pdev = omap_device_build(name, id - 1, oh, pdata, sizeof(*pdata));
 	kfree(pdata);
diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c
index ef4227ffa3b6..78af6d8cf2e2 100644
--- a/arch/arm/mach-omap2/powerdomain.c
+++ b/arch/arm/mach-omap2/powerdomain.c
@@ -1166,3 +1166,43 @@ int pwrdm_get_context_loss_count(struct powerdomain *pwrdm)
 	return count;
 }
 
+/**
+ * pwrdm_can_ever_lose_context - can this powerdomain ever lose context?
+ * @pwrdm: struct powerdomain *
+ *
+ * Given a struct powerdomain * @pwrdm, returns 1 if the powerdomain
+ * can lose either memory or logic context or if @pwrdm is invalid, or
+ * returns 0 otherwise.  This function is not concerned with how the
+ * powerdomain registers are programmed (i.e., to go off or not); it's
+ * concerned with whether it's ever possible for this powerdomain to
+ * go off while some other part of the chip is active.  This function
+ * assumes that every powerdomain can go to either ON or INACTIVE.
+ */
+bool pwrdm_can_ever_lose_context(struct powerdomain *pwrdm)
+{
+	int i;
+
+	if (!pwrdm) {
+		pr_debug("powerdomain: %s: invalid powerdomain pointer\n",
+			 __func__);
+		return 1;
+	}
+
+	if (pwrdm->pwrsts & PWRSTS_OFF)
+		return 1;
+
+	if (pwrdm->pwrsts & PWRSTS_RET) {
+		if (pwrdm->pwrsts_logic_ret & PWRSTS_OFF)
+			return 1;
+
+		for (i = 0; i < pwrdm->banks; i++)
+			if (pwrdm->pwrsts_mem_ret[i] & PWRSTS_OFF)
+				return 1;
+	}
+
+	for (i = 0; i < pwrdm->banks; i++)
+		if (pwrdm->pwrsts_mem_on[i] & PWRSTS_OFF)
+			return 1;
+
+	return 0;
+}
diff --git a/arch/arm/mach-omap2/powerdomain.h b/arch/arm/mach-omap2/powerdomain.h
index 5e0c033a21db..28a796ce07d7 100644
--- a/arch/arm/mach-omap2/powerdomain.h
+++ b/arch/arm/mach-omap2/powerdomain.h
@@ -244,6 +244,7 @@ int pwrdm_state_switch(struct powerdomain *pwrdm);
 int pwrdm_pre_transition(struct powerdomain *pwrdm);
 int pwrdm_post_transition(struct powerdomain *pwrdm);
 int pwrdm_get_context_loss_count(struct powerdomain *pwrdm);
+bool pwrdm_can_ever_lose_context(struct powerdomain *pwrdm);
 
 extern int omap_set_pwrdm_state(struct powerdomain *pwrdm, u8 state);
 
diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 4423b6dcc34f..e183351d047c 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -69,7 +69,7 @@ struct gpio_bank {
 	struct device *dev;
 	bool is_mpuio;
 	bool dbck_flag;
-
+	bool loses_context;
 	bool context_valid;
 	int stride;
 	u32 width;
@@ -1208,9 +1208,15 @@ static int omap_gpio_probe(struct platform_device *pdev)
 #ifdef CONFIG_OF_GPIO
 	bank->chip.of_node = of_node_get(node);
 #endif
-	if (!node) {
-		bank->get_context_loss_count =
-			pdata->get_context_loss_count;
+	if (node) {
+		if (!of_property_read_bool(node, "ti,gpio-always-on"))
+			bank->loses_context = true;
+	} else {
+		bank->loses_context = pdata->loses_context;
+
+		if (bank->loses_context)
+			bank->get_context_loss_count =
+				pdata->get_context_loss_count;
 	}
 
 	if (bank->regs->set_dataout && bank->regs->clr_dataout)
@@ -1367,7 +1373,7 @@ static int omap_gpio_runtime_resume(struct device *dev)
 	 * been initialised and so initialise it now. Also initialise
 	 * the context loss count.
 	 */
-	if (!bank->context_valid) {
+	if (bank->loses_context && !bank->context_valid) {
 		omap_gpio_init_context(bank);
 
 		if (bank->get_context_loss_count)
@@ -1388,15 +1394,17 @@ static int omap_gpio_runtime_resume(struct device *dev)
 	writel_relaxed(bank->context.risingdetect,
 		     bank->base + bank->regs->risingdetect);
 
-	if (!bank->get_context_loss_count) {
-		omap_gpio_restore_context(bank);
-	} else {
-		c = bank->get_context_loss_count(bank->dev);
-		if (c != bank->context_loss_count) {
+	if (bank->loses_context) {
+		if (!bank->get_context_loss_count) {
 			omap_gpio_restore_context(bank);
 		} else {
-			spin_unlock_irqrestore(&bank->lock, flags);
-			return 0;
+			c = bank->get_context_loss_count(bank->dev);
+			if (c != bank->context_loss_count) {
+				omap_gpio_restore_context(bank);
+			} else {
+				raw_spin_unlock_irqrestore(&bank->lock, flags);
+				return 0;
+			}
 		}
 	}
 
@@ -1468,7 +1476,7 @@ void omap2_gpio_prepare_for_idle(int pwr_mode)
 	struct gpio_bank *bank;
 
 	list_for_each_entry(bank, &omap_gpio_list, node) {
-		if (!BANK_USED(bank))
+		if (!BANK_USED(bank) || !bank->loses_context)
 			continue;
 
 		bank->power_mode = pwr_mode;
@@ -1482,7 +1490,7 @@ void omap2_gpio_resume_after_idle(void)
 	struct gpio_bank *bank;
 
 	list_for_each_entry(bank, &omap_gpio_list, node) {
-		if (!BANK_USED(bank))
+		if (!BANK_USED(bank) || !bank->loses_context)
 			continue;
 
 		pm_runtime_get_sync(bank->dev);
diff --git a/include/linux/platform_data/gpio-omap.h b/include/linux/platform_data/gpio-omap.h
index ff43e01b8ca9..cb2618147c34 100644
--- a/include/linux/platform_data/gpio-omap.h
+++ b/include/linux/platform_data/gpio-omap.h
@@ -198,6 +198,7 @@ struct omap_gpio_platform_data {
 	int bank_width;		/* GPIO bank width */
 	int bank_stride;	/* Only needed for omap1 MPUIO */
 	bool dbck_flag;		/* dbck required or not - True for OMAP3&4 */
+	bool loses_context;	/* whether the bank would ever lose context */
 	bool is_mpuio;		/* whether the bank is of type MPUIO */
 	u32 non_wakeup_gpios;
 
-- 
2.10.1