ACPI / PMIC: support PMIC operation region for CrystalCove

The Baytrail-T platform firmware has defined two customized operation
regions for PMIC chip Crystal Cove - one is for power resource handling
and one is for thermal: sensor temperature reporting, trip point setting,
etc. This patch adds support for them on top of the existing Crystal Cove
PMIC driver.

The reason to split code into a separate file intel_pmic.c is that there
are more PMIC drivers with ACPI operation region support coming and we can
re-use those code. The intel_pmic_opregion_data structure is created also
for this purpose: when we need to support a new PMIC's operation region,
we just need to fill those callbacks and the two register mapping tables.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Lee Jones <lee.jones@linaro.org> for the MFD part
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

5 files changed, 610 insertions, 0 deletions

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index b23fe37f67c0..df816456dc06 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -394,4 +394,21 @@ config ACPI_EXTLOG
           driver adds support for that functionality with corresponding
           tracepoint which carries that information to userspace.
 
+menuconfig PMIC_OPREGION
+        bool "PMIC (Power Management Integrated Circuit) operation region support"
+        help
+          Select this option to enable support for ACPI operation
+          region of the PMIC chip. The operation region can be used
+          to control power rails and sensor reading/writing on the
+          PMIC chip.
+
+if PMIC_OPREGION
+config CRC_PMIC_OPREGION
+        bool "ACPI operation region support for CrystalCove PMIC"
+        depends on INTEL_SOC_PMIC
+        help
+          This config adds ACPI operation region support for CrystalCove PMIC.
+
+endif
+
 endif   # ACPI
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index c3b2fcb729f3..38ea2a8245ed 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -87,3 +87,6 @@ obj-$(CONFIG_ACPI_PROCESSOR_AGGREGATOR) += acpi_pad.o
 obj-$(CONFIG_ACPI_APEI)         += apei/
 
 obj-$(CONFIG_ACPI_EXTLOG)       += acpi_extlog.o
+
+obj-$(CONFIG_PMIC_OPREGION)     += pmic/intel_pmic.o
+obj-$(CONFIG_CRC_PMIC_OPREGION) += pmic/intel_pmic_crc.o
diff --git a/drivers/acpi/pmic/intel_pmic.c b/drivers/acpi/pmic/intel_pmic.c
new file mode 100644
index 000000000000..a732e5d7e322
--- /dev/null
+++ b/drivers/acpi/pmic/intel_pmic.c
@@ -0,0 +1,354 @@
+/*
+ * intel_pmic.c - Intel PMIC operation region driver
+ *
+ * Copyright (C) 2014 Intel Corporation. All rights reserved.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/regmap.h>
+#include "intel_pmic.h"
+
+#define PMIC_POWER_OPREGION_ID          0x8d
+#define PMIC_THERMAL_OPREGION_ID        0x8c
+
+struct acpi_lpat {
+        int temp;
+        int raw;
+};
+
+struct intel_pmic_opregion {
+        struct mutex lock;
+        struct acpi_lpat *lpat;
+        int lpat_count;
+        struct regmap *regmap;
+        struct intel_pmic_opregion_data *data;
+};
+
+static int pmic_get_reg_bit(int address, struct pmic_table *table,
+                            int count, int *reg, int *bit)
+{
+        int i;
+
+        for (i = 0; i < count; i++) {
+                if (table[i].address == address) {
+                        *reg = table[i].reg;
+                        if (bit)
+                                *bit = table[i].bit;
+                        return 0;
+                }
+        }
+        return -ENOENT;
+}
+
+/**
+ * raw_to_temp(): Return temperature from raw value through LPAT table
+ *
+ * @lpat: the temperature_raw mapping table
+ * @count: the count of the above mapping table
+ * @raw: the raw value, used as a key to get the temerature from the
+ *       above mapping table
+ *
+ * A positive value will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+static int raw_to_temp(struct acpi_lpat *lpat, int count, int raw)
+{
+        int i, delta_temp, delta_raw, temp;
+
+        for (i = 0; i < count - 1; i++) {
+                if ((raw >= lpat[i].raw && raw <= lpat[i+1].raw) ||
+                    (raw <= lpat[i].raw && raw >= lpat[i+1].raw))
+                        break;
+        }
+
+        if (i == count - 1)
+                return -ENOENT;
+
+        delta_temp = lpat[i+1].temp - lpat[i].temp;
+        delta_raw = lpat[i+1].raw - lpat[i].raw;
+        temp = lpat[i].temp + (raw - lpat[i].raw) * delta_temp / delta_raw;
+
+        return temp;
+}
+
+/**
+ * temp_to_raw(): Return raw value from temperature through LPAT table
+ *
+ * @lpat: the temperature_raw mapping table
+ * @count: the count of the above mapping table
+ * @temp: the temperature, used as a key to get the raw value from the
+ *        above mapping table
+ *
+ * A positive value will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+static int temp_to_raw(struct acpi_lpat *lpat, int count, int temp)
+{
+        int i, delta_temp, delta_raw, raw;
+
+        for (i = 0; i < count - 1; i++) {
+                if (temp >= lpat[i].temp && temp <= lpat[i+1].temp)
+                        break;
+        }
+
+        if (i == count - 1)
+                return -ENOENT;
+
+        delta_temp = lpat[i+1].temp - lpat[i].temp;
+        delta_raw = lpat[i+1].raw - lpat[i].raw;
+        raw = lpat[i].raw + (temp - lpat[i].temp) * delta_raw / delta_temp;
+
+        return raw;
+}
+
+static void pmic_thermal_lpat(struct intel_pmic_opregion *opregion,
+                              acpi_handle handle, struct device *dev)
+{
+        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+        union acpi_object *obj_p, *obj_e;
+        int *lpat, i;
+        acpi_status status;
+
+        status = acpi_evaluate_object(handle, "LPAT", NULL, &buffer);
+        if (ACPI_FAILURE(status))
+                return;
+
+        obj_p = (union acpi_object *)buffer.pointer;
+        if (!obj_p || (obj_p->type != ACPI_TYPE_PACKAGE) ||
+            (obj_p->package.count % 2) || (obj_p->package.count < 4))
+                goto out;
+
+        lpat = devm_kmalloc(dev, sizeof(int) * obj_p->package.count,
+                            GFP_KERNEL);
+        if (!lpat)
+                goto out;
+
+        for (i = 0; i < obj_p->package.count; i++) {
+                obj_e = &obj_p->package.elements[i];
+                if (obj_e->type != ACPI_TYPE_INTEGER) {
+                        devm_kfree(dev, lpat);
+                        goto out;
+                }
+                lpat[i] = (s64)obj_e->integer.value;
+        }
+
+        opregion->lpat = (struct acpi_lpat *)lpat;
+        opregion->lpat_count = obj_p->package.count / 2;
+
+out:
+        kfree(buffer.pointer);
+}
+
+static acpi_status intel_pmic_power_handler(u32 function,
+                acpi_physical_address address, u32 bits, u64 *value64,
+                void *handler_context, void *region_context)
+{
+        struct intel_pmic_opregion *opregion = region_context;
+        struct regmap *regmap = opregion->regmap;
+        struct intel_pmic_opregion_data *d = opregion->data;
+        int reg, bit, result;
+
+        if (bits != 32 || !value64)
+                return AE_BAD_PARAMETER;
+
+        if (function == ACPI_WRITE && !(*value64 == 0 || *value64 == 1))
+                return AE_BAD_PARAMETER;
+
+        result = pmic_get_reg_bit(address, d->power_table,
+                                  d->power_table_count, &reg, &bit);
+        if (result == -ENOENT)
+                return AE_BAD_PARAMETER;
+
+        mutex_lock(&opregion->lock);
+
+        result = function == ACPI_READ ?
+                d->get_power(regmap, reg, bit, value64) :
+                d->update_power(regmap, reg, bit, *value64 == 1);
+
+        mutex_unlock(&opregion->lock);
+
+        return result ? AE_ERROR : AE_OK;
+}
+
+static int pmic_read_temp(struct intel_pmic_opregion *opregion,
+                          int reg, u64 *value)
+{
+        int raw_temp, temp;
+
+        if (!opregion->data->get_raw_temp)
+                return -ENXIO;
+
+        raw_temp = opregion->data->get_raw_temp(opregion->regmap, reg);
+        if (raw_temp < 0)
+                return raw_temp;
+
+        if (!opregion->lpat) {
+                *value = raw_temp;
+                return 0;
+        }
+
+        temp = raw_to_temp(opregion->lpat, opregion->lpat_count, raw_temp);
+        if (temp < 0)
+                return temp;
+
+        *value = temp;
+        return 0;
+}
+
+static int pmic_thermal_temp(struct intel_pmic_opregion *opregion, int reg,
+                             u32 function, u64 *value)
+{
+        return function == ACPI_READ ?
+                pmic_read_temp(opregion, reg, value) : -EINVAL;
+}
+
+static int pmic_thermal_aux(struct intel_pmic_opregion *opregion, int reg,
+                            u32 function, u64 *value)
+{
+        int raw_temp;
+
+        if (function == ACPI_READ)
+                return pmic_read_temp(opregion, reg, value);
+
+        if (!opregion->data->update_aux)
+                return -ENXIO;
+
+        if (opregion->lpat) {
+                raw_temp = temp_to_raw(opregion->lpat, opregion->lpat_count,
+                                       *value);
+                if (raw_temp < 0)
+                        return raw_temp;
+        } else {
+                raw_temp = *value;
+        }
+
+        return opregion->data->update_aux(opregion->regmap, reg, raw_temp);
+}
+
+static int pmic_thermal_pen(struct intel_pmic_opregion *opregion, int reg,
+                            u32 function, u64 *value)
+{
+        struct intel_pmic_opregion_data *d = opregion->data;
+        struct regmap *regmap = opregion->regmap;
+
+        if (!d->get_policy || !d->update_policy)
+                return -ENXIO;
+
+        if (function == ACPI_READ)
+                return d->get_policy(regmap, reg, value);
+
+        if (*value != 0 && *value != 1)
+                return -EINVAL;
+
+        return d->update_policy(regmap, reg, *value);
+}
+
+static bool pmic_thermal_is_temp(int address)
+{
+        return (address <= 0x3c) && !(address % 12);
+}
+
+static bool pmic_thermal_is_aux(int address)
+{
+        return (address >= 4 && address <= 0x40 && !((address - 4) % 12)) ||
+               (address >= 8 && address <= 0x44 && !((address - 8) % 12));
+}
+
+static bool pmic_thermal_is_pen(int address)
+{
+        return address >= 0x48 && address <= 0x5c;
+}
+
+static acpi_status intel_pmic_thermal_handler(u32 function,
+                acpi_physical_address address, u32 bits, u64 *value64,
+                void *handler_context, void *region_context)
+{
+        struct intel_pmic_opregion *opregion = region_context;
+        struct intel_pmic_opregion_data *d = opregion->data;
+        int reg, result;
+
+        if (bits != 32 || !value64)
+                return AE_BAD_PARAMETER;
+
+        result = pmic_get_reg_bit(address, d->thermal_table,
+                                  d->thermal_table_count, &reg, NULL);
+        if (result == -ENOENT)
+                return AE_BAD_PARAMETER;
+
+        mutex_lock(&opregion->lock);
+
+        if (pmic_thermal_is_temp(address))
+                result = pmic_thermal_temp(opregion, reg, function, value64);
+        else if (pmic_thermal_is_aux(address))
+                result = pmic_thermal_aux(opregion, reg, function, value64);
+        else if (pmic_thermal_is_pen(address))
+                result = pmic_thermal_pen(opregion, reg, function, value64);
+        else
+                result = -EINVAL;
+
+        mutex_unlock(&opregion->lock);
+
+        if (result < 0) {
+                if (result == -EINVAL)
+                        return AE_BAD_PARAMETER;
+                else
+                        return AE_ERROR;
+        }
+
+        return AE_OK;
+}
+
+int intel_pmic_install_opregion_handler(struct device *dev, acpi_handle handle,
+                                        struct regmap *regmap,
+                                        struct intel_pmic_opregion_data *d)
+{
+        acpi_status status;
+        struct intel_pmic_opregion *opregion;
+
+        if (!dev || !regmap || !d)
+                return -EINVAL;
+
+        if (!handle)
+                return -ENODEV;
+
+        opregion = devm_kzalloc(dev, sizeof(*opregion), GFP_KERNEL);
+        if (!opregion)
+                return -ENOMEM;
+
+        mutex_init(&opregion->lock);
+        opregion->regmap = regmap;
+        pmic_thermal_lpat(opregion, handle, dev);
+
+        status = acpi_install_address_space_handler(handle,
+                                                    PMIC_POWER_OPREGION_ID,
+                                                    intel_pmic_power_handler,
+                                                    NULL, opregion);
+        if (ACPI_FAILURE(status))
+                return -ENODEV;
+
+        status = acpi_install_address_space_handler(handle,
+                                                    PMIC_THERMAL_OPREGION_ID,
+                                                    intel_pmic_thermal_handler,
+                                                    NULL, opregion);
+        if (ACPI_FAILURE(status)) {
+                acpi_remove_address_space_handler(handle, PMIC_POWER_OPREGION_ID,
+                                                  intel_pmic_power_handler);
+                return -ENODEV;
+        }
+
+        opregion->data = d;
+        return 0;
+}
+EXPORT_SYMBOL_GPL(intel_pmic_install_opregion_handler);
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/acpi/pmic/intel_pmic.h b/drivers/acpi/pmic/intel_pmic.h
new file mode 100644
index 000000000000..d4e90af8f0dd
--- /dev/null
+++ b/drivers/acpi/pmic/intel_pmic.h
@@ -0,0 +1,25 @@
+#ifndef __INTEL_PMIC_H
+#define __INTEL_PMIC_H
+
+struct pmic_table {
+        int address;    /* operation region address */
+        int reg;        /* corresponding thermal register */
+        int bit;        /* control bit for power */
+};
+
+struct intel_pmic_opregion_data {
+        int (*get_power)(struct regmap *r, int reg, int bit, u64 *value);
+        int (*update_power)(struct regmap *r, int reg, int bit, bool on);
+        int (*get_raw_temp)(struct regmap *r, int reg);
+        int (*update_aux)(struct regmap *r, int reg, int raw_temp);
+        int (*get_policy)(struct regmap *r, int reg, u64 *value);
+        int (*update_policy)(struct regmap *r, int reg, int enable);
+        struct pmic_table *power_table;
+        int power_table_count;
+        struct pmic_table *thermal_table;
+        int thermal_table_count;
+};
+
+int intel_pmic_install_opregion_handler(struct device *dev, acpi_handle handle, struct regmap *regmap, struct intel_pmic_opregion_data *d);
+
+#endif
diff --git a/drivers/acpi/pmic/intel_pmic_crc.c b/drivers/acpi/pmic/intel_pmic_crc.c
new file mode 100644
index 000000000000..ef7d8ff95abe
--- /dev/null
+++ b/drivers/acpi/pmic/intel_pmic_crc.c
@@ -0,0 +1,211 @@
+/*
+ * intel_pmic_crc.c - Intel CrystalCove PMIC operation region driver
+ *
+ * Copyright (C) 2014 Intel Corporation. All rights reserved.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/mfd/intel_soc_pmic.h>
+#include <linux/regmap.h>
+#include <linux/platform_device.h>
+#include "intel_pmic.h"
+
+#define PWR_SOURCE_SELECT       BIT(1)
+
+#define PMIC_A0LOCK_REG         0xc5
+
+static struct pmic_table power_table[] = {
+        {
+                .address = 0x24,
+                .reg = 0x66,
+                .bit = 0x00,
+        },
+        {
+                .address = 0x48,
+                .reg = 0x5d,
+                .bit = 0x00,
+        },
+};
+
+static struct pmic_table thermal_table[] = {
+        {
+                .address = 0x00,
+                .reg = 0x75
+        },
+        {
+                .address = 0x04,
+                .reg = 0x95
+        },
+        {
+                .address = 0x08,
+                .reg = 0x97
+        },
+        {
+                .address = 0x0c,
+                .reg = 0x77
+        },
+        {
+                .address = 0x10,
+                .reg = 0x9a
+        },
+        {
+                .address = 0x14,
+                .reg = 0x9c
+        },
+        {
+                .address = 0x18,
+                .reg = 0x79
+        },
+        {
+                .address = 0x1c,
+                .reg = 0x9f
+        },
+        {
+                .address = 0x20,
+                .reg = 0xa1
+        },
+        {
+                .address = 0x48,
+                .reg = 0x94
+        },
+        {
+                .address = 0x4c,
+                .reg = 0x99
+        },
+        {
+                .address = 0x50,
+                .reg = 0x9e
+        },
+};
+
+static int intel_crc_pmic_get_power(struct regmap *regmap, int reg,
+                                    int bit, u64 *value)
+{
+        int data;
+
+        if (regmap_read(regmap, reg, &data))
+                return -EIO;
+
+        *value = (data & PWR_SOURCE_SELECT) && (data & BIT(bit)) ? 1 : 0;
+        return 0;
+}
+
+static int intel_crc_pmic_update_power(struct regmap *regmap, int reg,
+                                       int bit, bool on)
+{
+        int data;
+
+        if (regmap_read(regmap, reg, &data))
+                return -EIO;
+
+        if (on) {
+                data |= PWR_SOURCE_SELECT | BIT(bit);
+        } else {
+                data &= ~BIT(bit);
+                data |= PWR_SOURCE_SELECT;
+        }
+
+        if (regmap_write(regmap, reg, data))
+                return -EIO;
+        return 0;
+}
+
+static int intel_crc_pmic_get_raw_temp(struct regmap *regmap, int reg)
+{
+        int temp_l, temp_h;
+
+        /*
+         * Raw temperature value is 10bits: 8bits in reg
+         * and 2bits in reg-1: bit0,1
+         */
+        if (regmap_read(regmap, reg, &temp_l) ||
+            regmap_read(regmap, reg - 1, &temp_h))
+                return -EIO;
+
+        return temp_l | (temp_h & 0x3) << 8;
+}
+
+static int intel_crc_pmic_update_aux(struct regmap *regmap, int reg, int raw)
+{
+        return regmap_write(regmap, reg, raw) ||
+                regmap_update_bits(regmap, reg - 1, 0x3, raw >> 8) ? -EIO : 0;
+}
+
+static int intel_crc_pmic_get_policy(struct regmap *regmap, int reg, u64 *value)
+{
+        int pen;
+
+        if (regmap_read(regmap, reg, &pen))
+                return -EIO;
+        *value = pen >> 7;
+        return 0;
+}
+
+static int intel_crc_pmic_update_policy(struct regmap *regmap,
+                                        int reg, int enable)
+{
+        int alert0;
+
+        /* Update to policy enable bit requires unlocking a0lock */
+        if (regmap_read(regmap, PMIC_A0LOCK_REG, &alert0))
+                return -EIO;
+
+        if (regmap_update_bits(regmap, PMIC_A0LOCK_REG, 0x01, 0))
+                return -EIO;
+
+        if (regmap_update_bits(regmap, reg, 0x80, enable << 7))
+                return -EIO;
+
+        /* restore alert0 */
+        if (regmap_write(regmap, PMIC_A0LOCK_REG, alert0))
+                return -EIO;
+
+        return 0;
+}
+
+static struct intel_pmic_opregion_data intel_crc_pmic_opregion_data = {
+        .get_power      = intel_crc_pmic_get_power,
+        .update_power   = intel_crc_pmic_update_power,
+        .get_raw_temp   = intel_crc_pmic_get_raw_temp,
+        .update_aux     = intel_crc_pmic_update_aux,
+        .get_policy     = intel_crc_pmic_get_policy,
+        .update_policy  = intel_crc_pmic_update_policy,
+        .power_table    = power_table,
+        .power_table_count= ARRAY_SIZE(power_table),
+        .thermal_table  = thermal_table,
+        .thermal_table_count = ARRAY_SIZE(thermal_table),
+};
+
+static int intel_crc_pmic_opregion_probe(struct platform_device *pdev)
+{
+        struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
+        return intel_pmic_install_opregion_handler(&pdev->dev,
+                        ACPI_HANDLE(pdev->dev.parent), pmic->regmap,
+                        &intel_crc_pmic_opregion_data);
+}
+
+static struct platform_driver intel_crc_pmic_opregion_driver = {
+        .probe = intel_crc_pmic_opregion_probe,
+        .driver = {
+                .name = "crystal_cove_pmic",
+        },
+};
+
+static int __init intel_crc_pmic_opregion_driver_init(void)
+{
+        return platform_driver_register(&intel_crc_pmic_opregion_driver);
+}
+module_init(intel_crc_pmic_opregion_driver_init);
+
+MODULE_DESCRIPTION("CrystalCove ACPI opration region driver");
+MODULE_LICENSE("GPL");