mach-ux500: voltage domain regulators for DB8500

The DB8500 has ePOD:s (electronic power domains) which are possible
to switch on/off to deactivate silicon blocks on the DB8500 SoC
by cutting their power without retention. We model these as simple
regulators with one bit on/off settings.

Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Bengt Jonsson <bengt.g.jonsson@stericsson.com>
Signed-off-by: Sundar Iyer <sundar.iyer@stericsson.com>
Signed-off-by: Jonas Aberg <jonas.aberg@stericsson.com>
Signed-off-by: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
Signed-off-by: Martin Persson <martin.persson@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 558 insertions, 0 deletions

diff --git a/drivers/regulator/db8500-prcmu.c b/drivers/regulator/db8500-prcmu.c
new file mode 100644
index 000000000000..1089a961616e
--- /dev/null
+++ b/drivers/regulator/db8500-prcmu.c
@@ -0,0 +1,558 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * License Terms: GNU General Public License v2
+ * Authors: Sundar Iyer <sundar.iyer@stericsson.com> for ST-Ericsson
+ *          Bengt Jonsson <bengt.g.jonsson@stericsson.com> for ST-Ericsson
+ *
+ * Power domain regulators on DB8500
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/spinlock.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/db8500-prcmu.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/db8500-prcmu.h>
+
+/*
+ * power state reference count
+ */
+static int power_state_active_cnt; /* will initialize to zero */
+static DEFINE_SPINLOCK(power_state_active_lock);
+
+static void power_state_active_enable(void)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&power_state_active_lock, flags);
+	power_state_active_cnt++;
+	spin_unlock_irqrestore(&power_state_active_lock, flags);
+}
+
+static int power_state_active_disable(void)
+{
+	int ret = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&power_state_active_lock, flags);
+	if (power_state_active_cnt <= 0) {
+		pr_err("power state: unbalanced enable/disable calls\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	power_state_active_cnt--;
+out:
+	spin_unlock_irqrestore(&power_state_active_lock, flags);
+	return ret;
+}
+
+/*
+ * Exported interface for CPUIdle only. This function is called when interrupts
+ * are turned off. Hence, no locking.
+ */
+int power_state_active_is_enabled(void)
+{
+	return (power_state_active_cnt > 0);
+}
+
+/**
+ * struct db8500_regulator_info - db8500 regulator information
+ * @dev: device pointer
+ * @desc: regulator description
+ * @rdev: regulator device pointer
+ * @is_enabled: status of the regulator
+ * @epod_id: id for EPOD (power domain)
+ * @is_ramret: RAM retention switch for EPOD (power domain)
+ * @operating_point: operating point (only for vape, to be removed)
+ *
+ */
+struct db8500_regulator_info {
+	struct device *dev;
+	struct regulator_desc desc;
+	struct regulator_dev *rdev;
+	bool is_enabled;
+	u16 epod_id;
+	bool is_ramret;
+	bool exclude_from_power_state;
+	unsigned int operating_point;
+};
+
+static int db8500_regulator_enable(struct regulator_dev *rdev)
+{
+	struct db8500_regulator_info *info = rdev_get_drvdata(rdev);
+
+	if (info == NULL)
+		return -EINVAL;
+
+	dev_vdbg(rdev_get_dev(rdev), "regulator-%s-enable\n",
+		info->desc.name);
+
+	info->is_enabled = true;
+	if (!info->exclude_from_power_state)
+		power_state_active_enable();
+
+	return 0;
+}
+
+static int db8500_regulator_disable(struct regulator_dev *rdev)
+{
+	struct db8500_regulator_info *info = rdev_get_drvdata(rdev);
+	int ret = 0;
+
+	if (info == NULL)
+		return -EINVAL;
+
+	dev_vdbg(rdev_get_dev(rdev), "regulator-%s-disable\n",
+		info->desc.name);
+
+	info->is_enabled = false;
+	if (!info->exclude_from_power_state)
+		ret = power_state_active_disable();
+
+	return ret;
+}
+
+static int db8500_regulator_is_enabled(struct regulator_dev *rdev)
+{
+	struct db8500_regulator_info *info = rdev_get_drvdata(rdev);
+
+	if (info == NULL)
+		return -EINVAL;
+
+	dev_vdbg(rdev_get_dev(rdev), "regulator-%s-is_enabled (is_enabled):"
+		" %i\n", info->desc.name, info->is_enabled);
+
+	return info->is_enabled;
+}
+
+/* db8500 regulator operations */
+static struct regulator_ops db8500_regulator_ops = {
+	.enable			= db8500_regulator_enable,
+	.disable		= db8500_regulator_disable,
+	.is_enabled		= db8500_regulator_is_enabled,
+};
+
+/*
+ * EPOD control
+ */
+static bool epod_on[NUM_EPOD_ID];
+static bool epod_ramret[NUM_EPOD_ID];
+
+static int enable_epod(u16 epod_id, bool ramret)
+{
+	int ret;
+
+	if (ramret) {
+		if (!epod_on[epod_id]) {
+			ret = prcmu_set_epod(epod_id, EPOD_STATE_RAMRET);
+			if (ret < 0)
+				return ret;
+		}
+		epod_ramret[epod_id] = true;
+	} else {
+		ret = prcmu_set_epod(epod_id, EPOD_STATE_ON);
+		if (ret < 0)
+			return ret;
+		epod_on[epod_id] = true;
+	}
+
+	return 0;
+}
+
+static int disable_epod(u16 epod_id, bool ramret)
+{
+	int ret;
+
+	if (ramret) {
+		if (!epod_on[epod_id]) {
+			ret = prcmu_set_epod(epod_id, EPOD_STATE_OFF);
+			if (ret < 0)
+				return ret;
+		}
+		epod_ramret[epod_id] = false;
+	} else {
+		if (epod_ramret[epod_id]) {
+			ret = prcmu_set_epod(epod_id, EPOD_STATE_RAMRET);
+			if (ret < 0)
+				return ret;
+		} else {
+			ret = prcmu_set_epod(epod_id, EPOD_STATE_OFF);
+			if (ret < 0)
+				return ret;
+		}
+		epod_on[epod_id] = false;
+	}
+
+	return 0;
+}
+
+/*
+ * Regulator switch
+ */
+static int db8500_regulator_switch_enable(struct regulator_dev *rdev)
+{
+	struct db8500_regulator_info *info = rdev_get_drvdata(rdev);
+	int ret;
+
+	if (info == NULL)
+		return -EINVAL;
+
+	dev_vdbg(rdev_get_dev(rdev), "regulator-switch-%s-enable\n",
+		info->desc.name);
+
+	ret = enable_epod(info->epod_id, info->is_ramret);
+	if (ret < 0) {
+		dev_err(rdev_get_dev(rdev),
+			"regulator-switch-%s-enable: prcmu call failed\n",
+			info->desc.name);
+		goto out;
+	}
+
+	info->is_enabled = true;
+out:
+	return ret;
+}
+
+static int db8500_regulator_switch_disable(struct regulator_dev *rdev)
+{
+	struct db8500_regulator_info *info = rdev_get_drvdata(rdev);
+	int ret;
+
+	if (info == NULL)
+		return -EINVAL;
+
+	dev_vdbg(rdev_get_dev(rdev), "regulator-switch-%s-disable\n",
+		info->desc.name);
+
+	ret = disable_epod(info->epod_id, info->is_ramret);
+	if (ret < 0) {
+		dev_err(rdev_get_dev(rdev),
+			"regulator_switch-%s-disable: prcmu call failed\n",
+			info->desc.name);
+		goto out;
+	}
+
+	info->is_enabled = 0;
+out:
+	return ret;
+}
+
+static int db8500_regulator_switch_is_enabled(struct regulator_dev *rdev)
+{
+	struct db8500_regulator_info *info = rdev_get_drvdata(rdev);
+
+	if (info == NULL)
+		return -EINVAL;
+
+	dev_vdbg(rdev_get_dev(rdev),
+		"regulator-switch-%s-is_enabled (is_enabled): %i\n",
+		info->desc.name, info->is_enabled);
+
+	return info->is_enabled;
+}
+
+static struct regulator_ops db8500_regulator_switch_ops = {
+	.enable			= db8500_regulator_switch_enable,
+	.disable		= db8500_regulator_switch_disable,
+	.is_enabled		= db8500_regulator_switch_is_enabled,
+};
+
+/*
+ * Regulator information
+ */
+static struct db8500_regulator_info
+		db8500_regulator_info[DB8500_NUM_REGULATORS] = {
+	[DB8500_REGULATOR_VAPE] = {
+		.desc = {
+			.name	= "db8500-vape",
+			.id	= DB8500_REGULATOR_VAPE,
+			.ops	= &db8500_regulator_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+	},
+	[DB8500_REGULATOR_VARM] = {
+		.desc = {
+			.name	= "db8500-varm",
+			.id	= DB8500_REGULATOR_VARM,
+			.ops	= &db8500_regulator_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+	},
+	[DB8500_REGULATOR_VMODEM] = {
+		.desc = {
+			.name	= "db8500-vmodem",
+			.id	= DB8500_REGULATOR_VMODEM,
+			.ops	= &db8500_regulator_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+	},
+	[DB8500_REGULATOR_VPLL] = {
+		.desc = {
+			.name	= "db8500-vpll",
+			.id	= DB8500_REGULATOR_VPLL,
+			.ops	= &db8500_regulator_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+	},
+	[DB8500_REGULATOR_VSMPS1] = {
+		.desc = {
+			.name	= "db8500-vsmps1",
+			.id	= DB8500_REGULATOR_VSMPS1,
+			.ops	= &db8500_regulator_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+	},
+	[DB8500_REGULATOR_VSMPS2] = {
+		.desc = {
+			.name	= "db8500-vsmps2",
+			.id	= DB8500_REGULATOR_VSMPS2,
+			.ops	= &db8500_regulator_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+		.exclude_from_power_state = true,
+	},
+	[DB8500_REGULATOR_VSMPS3] = {
+		.desc = {
+			.name	= "db8500-vsmps3",
+			.id	= DB8500_REGULATOR_VSMPS3,
+			.ops	= &db8500_regulator_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+	},
+	[DB8500_REGULATOR_VRF1] = {
+		.desc = {
+			.name	= "db8500-vrf1",
+			.id	= DB8500_REGULATOR_VRF1,
+			.ops	= &db8500_regulator_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+	},
+	[DB8500_REGULATOR_SWITCH_SVAMMDSP] = {
+		.desc = {
+			.name	= "db8500-sva-mmdsp",
+			.id	= DB8500_REGULATOR_SWITCH_SVAMMDSP,
+			.ops	= &db8500_regulator_switch_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+		.epod_id = EPOD_ID_SVAMMDSP,
+	},
+	[DB8500_REGULATOR_SWITCH_SVAMMDSPRET] = {
+		.desc = {
+			.name	= "db8500-sva-mmdsp-ret",
+			.id	= DB8500_REGULATOR_SWITCH_SVAMMDSPRET,
+			.ops	= &db8500_regulator_switch_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+		.epod_id = EPOD_ID_SVAMMDSP,
+		.is_ramret = true,
+	},
+	[DB8500_REGULATOR_SWITCH_SVAPIPE] = {
+		.desc = {
+			.name	= "db8500-sva-pipe",
+			.id	= DB8500_REGULATOR_SWITCH_SVAPIPE,
+			.ops	= &db8500_regulator_switch_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+		.epod_id = EPOD_ID_SVAPIPE,
+	},
+	[DB8500_REGULATOR_SWITCH_SIAMMDSP] = {
+		.desc = {
+			.name	= "db8500-sia-mmdsp",
+			.id	= DB8500_REGULATOR_SWITCH_SIAMMDSP,
+			.ops	= &db8500_regulator_switch_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+		.epod_id = EPOD_ID_SIAMMDSP,
+	},
+	[DB8500_REGULATOR_SWITCH_SIAMMDSPRET] = {
+		.desc = {
+			.name	= "db8500-sia-mmdsp-ret",
+			.id	= DB8500_REGULATOR_SWITCH_SIAMMDSPRET,
+			.ops	= &db8500_regulator_switch_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+		.epod_id = EPOD_ID_SIAMMDSP,
+		.is_ramret = true,
+	},
+	[DB8500_REGULATOR_SWITCH_SIAPIPE] = {
+		.desc = {
+			.name	= "db8500-sia-pipe",
+			.id	= DB8500_REGULATOR_SWITCH_SIAPIPE,
+			.ops	= &db8500_regulator_switch_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+		.epod_id = EPOD_ID_SIAPIPE,
+	},
+	[DB8500_REGULATOR_SWITCH_SGA] = {
+		.desc = {
+			.name	= "db8500-sga",
+			.id	= DB8500_REGULATOR_SWITCH_SGA,
+			.ops	= &db8500_regulator_switch_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+		.epod_id = EPOD_ID_SGA,
+	},
+	[DB8500_REGULATOR_SWITCH_B2R2_MCDE] = {
+		.desc = {
+			.name	= "db8500-b2r2-mcde",
+			.id	= DB8500_REGULATOR_SWITCH_B2R2_MCDE,
+			.ops	= &db8500_regulator_switch_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+		.epod_id = EPOD_ID_B2R2_MCDE,
+	},
+	[DB8500_REGULATOR_SWITCH_ESRAM12] = {
+		.desc = {
+			.name	= "db8500-esram12",
+			.id	= DB8500_REGULATOR_SWITCH_ESRAM12,
+			.ops	= &db8500_regulator_switch_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+		.epod_id	= EPOD_ID_ESRAM12,
+		.is_enabled	= true,
+	},
+	[DB8500_REGULATOR_SWITCH_ESRAM12RET] = {
+		.desc = {
+			.name	= "db8500-esram12-ret",
+			.id	= DB8500_REGULATOR_SWITCH_ESRAM12RET,
+			.ops	= &db8500_regulator_switch_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+		.epod_id = EPOD_ID_ESRAM12,
+		.is_ramret = true,
+	},
+	[DB8500_REGULATOR_SWITCH_ESRAM34] = {
+		.desc = {
+			.name	= "db8500-esram34",
+			.id	= DB8500_REGULATOR_SWITCH_ESRAM34,
+			.ops	= &db8500_regulator_switch_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+		.epod_id	= EPOD_ID_ESRAM34,
+		.is_enabled	= true,
+	},
+	[DB8500_REGULATOR_SWITCH_ESRAM34RET] = {
+		.desc = {
+			.name	= "db8500-esram34-ret",
+			.id	= DB8500_REGULATOR_SWITCH_ESRAM34RET,
+			.ops	= &db8500_regulator_switch_ops,
+			.type	= REGULATOR_VOLTAGE,
+			.owner	= THIS_MODULE,
+		},
+		.epod_id = EPOD_ID_ESRAM34,
+		.is_ramret = true,
+	},
+};
+
+static int __devinit db8500_regulator_probe(struct platform_device *pdev)
+{
+	struct regulator_init_data *db8500_init_data = mfd_get_data(pdev);
+	int i, err;
+
+	/* register all regulators */
+	for (i = 0; i < ARRAY_SIZE(db8500_regulator_info); i++) {
+		struct db8500_regulator_info *info;
+		struct regulator_init_data *init_data = &db8500_init_data[i];
+
+		/* assign per-regulator data */
+		info = &db8500_regulator_info[i];
+		info->dev = &pdev->dev;
+
+		/* register with the regulator framework */
+		info->rdev = regulator_register(&info->desc, &pdev->dev,
+				init_data, info);
+		if (IS_ERR(info->rdev)) {
+			err = PTR_ERR(info->rdev);
+			dev_err(&pdev->dev, "failed to register %s: err %i\n",
+				info->desc.name, err);
+
+			/* if failing, unregister all earlier regulators */
+			i--;
+			while (i >= 0) {
+				info = &db8500_regulator_info[i];
+				regulator_unregister(info->rdev);
+				i--;
+			}
+			return err;
+		}
+
+		dev_dbg(rdev_get_dev(info->rdev),
+			"regulator-%s-probed\n", info->desc.name);
+	}
+
+	return 0;
+}
+
+static int __exit db8500_regulator_remove(struct platform_device *pdev)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(db8500_regulator_info); i++) {
+		struct db8500_regulator_info *info;
+		info = &db8500_regulator_info[i];
+
+		dev_vdbg(rdev_get_dev(info->rdev),
+			"regulator-%s-remove\n", info->desc.name);
+
+		regulator_unregister(info->rdev);
+	}
+
+	return 0;
+}
+
+static struct platform_driver db8500_regulator_driver = {
+	.driver = {
+		.name = "db8500-prcmu-regulators",
+		.owner = THIS_MODULE,
+	},
+	.probe = db8500_regulator_probe,
+	.remove = __exit_p(db8500_regulator_remove),
+};
+
+static int __init db8500_regulator_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&db8500_regulator_driver);
+	if (ret < 0)
+		return -ENODEV;
+
+	return 0;
+}
+
+static void __exit db8500_regulator_exit(void)
+{
+	platform_driver_unregister(&db8500_regulator_driver);
+}
+
+arch_initcall(db8500_regulator_init);
+module_exit(db8500_regulator_exit);
+
+MODULE_AUTHOR("STMicroelectronics/ST-Ericsson");
+MODULE_DESCRIPTION("DB8500 regulator driver");
+MODULE_LICENSE("GPL v2");