regulator: dbx500-prcmu: add support for special regulators

The DMA driver needs to be able to enable/disable its regulator
in atomic context, which is not supported by the regulator framework.
This patch adds an interface for such special cases.

Change-Id: I3e6efab1cb2be47cdcea18bf1038ee8be54a4bea
Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>
Signed-off-by: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/32109

2 files changed, 160 insertions, 0 deletions

diff --git a/drivers/regulator/dbx500-prcmu.c b/drivers/regulator/dbx500-prcmu.c
index 409cb8574fe..3bc6e0e5189 100644
--- a/drivers/regulator/dbx500-prcmu.c
+++ b/drivers/regulator/dbx500-prcmu.c
@@ -60,3 +60,88 @@ struct ux500_regulator {
 	void (*enable)(void);
 	int (*disable)(void);
 };
+static struct ux500_regulator ux500_atomic_regulators[] = {
+	{
+		.name    = "dma40.0",
+		.enable  = power_state_active_enable,
+		.disable = power_state_active_disable,
+	},
+	{
+		.name = "ssp0",
+		.enable  = power_state_active_enable,
+		.disable = power_state_active_disable,
+	},
+	{
+		.name = "ssp1",
+		.enable  = power_state_active_enable,
+		.disable = power_state_active_disable,
+	},
+	{
+		.name = "spi0",
+		.enable  = power_state_active_enable,
+		.disable = power_state_active_disable,
+	},
+	{
+		.name = "spi1",
+		.enable  = power_state_active_enable,
+		.disable = power_state_active_disable,
+	},
+	{
+		.name = "spi2",
+		.enable  = power_state_active_enable,
+		.disable = power_state_active_disable,
+	},
+	{
+		.name = "spi3",
+		.enable  = power_state_active_enable,
+		.disable = power_state_active_disable,
+	},
+	{
+		.name = "cryp1",
+		.enable  = power_state_active_enable,
+		.disable = power_state_active_disable,
+	},
+	{
+		.name = "hash1",
+		.enable  = power_state_active_enable,
+		.disable = power_state_active_disable,
+	},
+};
+
+struct ux500_regulator *__must_check ux500_regulator_get(struct device *dev)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ux500_atomic_regulators); i++) {
+		if (!strcmp(dev_name(dev), ux500_atomic_regulators[i].name))
+			return &ux500_atomic_regulators[i];
+	}
+
+	return  ERR_PTR(-EINVAL);
+}
+EXPORT_SYMBOL_GPL(ux500_regulator_get);
+
+int ux500_regulator_atomic_enable(struct ux500_regulator *regulator)
+{
+	if (regulator) {
+		regulator->enable();
+		return 0;
+	}
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(ux500_regulator_atomic_enable);
+
+int ux500_regulator_atomic_disable(struct ux500_regulator *regulator)
+{
+	if (regulator)
+		return regulator->disable();
+	else
+		return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(ux500_regulator_atomic_disable);
+
+void ux500_regulator_put(struct ux500_regulator *regulator)
+{
+	/* Here for symetric reasons and for possible future use */
+}
+EXPORT_SYMBOL_GPL(ux500_regulator_put);
diff --git a/include/linux/mfd/dbx500-prcmu.h b/include/linux/mfd/dbx500-prcmu.h
index 7da5694f8ca..072a4c70059 100644
--- a/include/linux/mfd/dbx500-prcmu.h
+++ b/include/linux/mfd/dbx500-prcmu.h
@@ -10,6 +10,7 @@
 
 #include <linux/interrupt.h>
 #include <linux/notifier.h>
+#include <linux/err.h>
 #include <asm/mach-types.h>
 
 /* PRCMU Wakeup defines */
@@ -549,4 +550,78 @@ static inline int prcmu_qos_remove_notifier(int prcmu_qos_class,
 
 #endif
 
+struct ux500_regulator;
+
+#ifdef CONFIG_REGULATOR
+/*
+ * NOTE! The device will be connected to the correct regulator by this
+ * new framework. A list with connections will match up dev_name(dev)
+ * to the specific regulator. This follows the same principle as the
+ * normal regulator framework.
+ *
+ * This framework shall only be used in special cases when a regulator
+ * has to be enabled/disabled in atomic context.
+ */
+
+/**
+ * ux500_regulator_get()
+ *
+ * @dev: Drivers device struct
+ *
+ * Returns a ux500_regulator struct. Shall be used as argument for
+ * ux500_regulator_atomic_enable/disable calls.
+ * Return ERR_PTR(-EINVAL) upon no matching regulator found.
+ */
+struct ux500_regulator *__must_check ux500_regulator_get(struct device *dev);
+
+/**
+ * ux500_regulator_atomic_enable()
+ *
+ * @regulator: Regulator handle, provided from ux500_regulator_get.
+ *
+ * The enable/disable functions keep an internal counter, so every
+ * enable must be paired with an disable in order to turn off regulator.
+ */
+int ux500_regulator_atomic_enable(struct ux500_regulator *regulator);
+
+/**
+ * ux500_regulator_atomic_disable()
+ *
+ * @regulator: Regulator handle, provided from ux500_regulator_get.
+ *
+ */
+int ux500_regulator_atomic_disable(struct ux500_regulator *regulator);
+
+/**
+ * ux500_regulator_put()
+ *
+ * @regulator: Regulator handle, provided from ux500_regulator_get.
+ */
+void ux500_regulator_put(struct ux500_regulator *regulator);
+
+#else
+
+static inline struct ux500_regulator *__must_check
+ux500_regulator_get(struct device *dev)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+static inline int
+ux500_regulator_atomic_enable(struct ux500_regulator *regulator)
+{
+	return -EINVAL;
+}
+
+static inline int
+ux500_regulator_atomic_disable(struct ux500_regulator *regulator)
+{
+	return -EINVAL;
+}
+
+static inline void ux500_regulator_put(struct ux500_regulator *regulator)
+{
+}
+#endif /* CONFIG_REGULATOR */
+
 #endif /* __MACH_PRCMU_H */