Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

[mirror_ubuntu-zesty-kernel.git] / drivers / base / regmap / regmap-irq.c

/*
 * regmap based irq_chip
 *
 * Copyright 2011 Wolfson Microelectronics plc
 *
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 *
 * 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.
 */

#include <linux/device.h>
#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/slab.h>

#include "internal.h"

struct regmap_irq_chip_data {
        struct mutex lock;
        struct irq_chip irq_chip;

        struct regmap *map;
        const struct regmap_irq_chip *chip;

        int irq_base;
        struct irq_domain *domain;

        int irq;
        int wake_count;

        void *status_reg_buf;
        unsigned int *status_buf;
        unsigned int *mask_buf;
        unsigned int *mask_buf_def;
        unsigned int *wake_buf;

        unsigned int irq_reg_stride;
};

static inline const
struct regmap_irq *irq_to_regmap_irq(struct regmap_irq_chip_data *data,
                                     int irq)
{
        return &data->chip->irqs[irq];
}

static void regmap_irq_lock(struct irq_data *data)
{
        struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);

        mutex_lock(&d->lock);
}

static void regmap_irq_sync_unlock(struct irq_data *data)
{
        struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
        struct regmap *map = d->map;
        int i, ret;
        u32 reg;
        u32 unmask_offset;

        if (d->chip->runtime_pm) {
                ret = pm_runtime_get_sync(map->dev);
                if (ret < 0)
                        dev_err(map->dev, "IRQ sync failed to resume: %d\n",
                                ret);
        }

        /*
         * If there's been a change in the mask write it back to the
         * hardware.  We rely on the use of the regmap core cache to
         * suppress pointless writes.
         */
        for (i = 0; i < d->chip->num_regs; i++) {
                reg = d->chip->mask_base +
                        (i * map->reg_stride * d->irq_reg_stride);
                if (d->chip->mask_invert) {
                        ret = regmap_update_bits(d->map, reg,
                                         d->mask_buf_def[i], ~d->mask_buf[i]);
                } else if (d->chip->unmask_base) {
                        /* set mask with mask_base register */
                        ret = regmap_update_bits(d->map, reg,
                                        d->mask_buf_def[i], ~d->mask_buf[i]);
                        if (ret < 0)
                                dev_err(d->map->dev,
                                        "Failed to sync unmasks in %x\n",
                                        reg);
                        unmask_offset = d->chip->unmask_base -
                                                        d->chip->mask_base;
                        /* clear mask with unmask_base register */
                        ret = regmap_update_bits(d->map,
                                        reg + unmask_offset,
                                        d->mask_buf_def[i],
                                        d->mask_buf[i]);
                } else {
                        ret = regmap_update_bits(d->map, reg,
                                         d->mask_buf_def[i], d->mask_buf[i]);
                }
                if (ret != 0)
                        dev_err(d->map->dev, "Failed to sync masks in %x\n",
                                reg);

                reg = d->chip->wake_base +
                        (i * map->reg_stride * d->irq_reg_stride);
                if (d->wake_buf) {
                        if (d->chip->wake_invert)
                                ret = regmap_update_bits(d->map, reg,
                                                         d->mask_buf_def[i],
                                                         ~d->wake_buf[i]);
                        else
                                ret = regmap_update_bits(d->map, reg,
                                                         d->mask_buf_def[i],
                                                         d->wake_buf[i]);
                        if (ret != 0)
                                dev_err(d->map->dev,
                                        "Failed to sync wakes in %x: %d\n",
                                        reg, ret);
                }

                if (!d->chip->init_ack_masked)
                        continue;
                /*
                 * Ack all the masked interrupts unconditionally,
                 * OR if there is masked interrupt which hasn't been Acked,
                 * it'll be ignored in irq handler, then may introduce irq storm
                 */
                if (d->mask_buf[i] && (d->chip->ack_base || d->chip->use_ack)) {
                        reg = d->chip->ack_base +
                                (i * map->reg_stride * d->irq_reg_stride);
                        /* some chips ack by write 0 */
                        if (d->chip->ack_invert)
                                ret = regmap_write(map, reg, ~d->mask_buf[i]);
                        else
                                ret = regmap_write(map, reg, d->mask_buf[i]);
                        if (ret != 0)
                                dev_err(d->map->dev, "Failed to ack 0x%x: %d\n",
                                        reg, ret);
                }
        }

        if (d->chip->runtime_pm)
                pm_runtime_put(map->dev);

        /* If we've changed our wakeup count propagate it to the parent */
        if (d->wake_count < 0)
                for (i = d->wake_count; i < 0; i++)
                        irq_set_irq_wake(d->irq, 0);
        else if (d->wake_count > 0)
                for (i = 0; i < d->wake_count; i++)
                        irq_set_irq_wake(d->irq, 1);

        d->wake_count = 0;

        mutex_unlock(&d->lock);
}

static void regmap_irq_enable(struct irq_data *data)
{
        struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
        struct regmap *map = d->map;
        const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->hwirq);

        d->mask_buf[irq_data->reg_offset / map->reg_stride] &= ~irq_data->mask;
}

static void regmap_irq_disable(struct irq_data *data)
{
        struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
        struct regmap *map = d->map;
        const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->hwirq);

        d->mask_buf[irq_data->reg_offset / map->reg_stride] |= irq_data->mask;
}

static int regmap_irq_set_wake(struct irq_data *data, unsigned int on)
{
        struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
        struct regmap *map = d->map;
        const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->hwirq);

        if (on) {
                if (d->wake_buf)
                        d->wake_buf[irq_data->reg_offset / map->reg_stride]
                                &= ~irq_data->mask;
                d->wake_count++;
        } else {
                if (d->wake_buf)
                        d->wake_buf[irq_data->reg_offset / map->reg_stride]
                                |= irq_data->mask;
                d->wake_count--;
        }

        return 0;
}

static const struct irq_chip regmap_irq_chip = {
        .irq_bus_lock           = regmap_irq_lock,
        .irq_bus_sync_unlock    = regmap_irq_sync_unlock,
        .irq_disable            = regmap_irq_disable,
        .irq_enable             = regmap_irq_enable,
        .irq_set_wake           = regmap_irq_set_wake,
};

static irqreturn_t regmap_irq_thread(int irq, void *d)
{
        struct regmap_irq_chip_data *data = d;
        const struct regmap_irq_chip *chip = data->chip;
        struct regmap *map = data->map;
        int ret, i;
        bool handled = false;
        u32 reg;

        if (chip->runtime_pm) {
                ret = pm_runtime_get_sync(map->dev);
                if (ret < 0) {
                        dev_err(map->dev, "IRQ thread failed to resume: %d\n",
                                ret);
                        pm_runtime_put(map->dev);
                        return IRQ_NONE;
                }
        }

        /*
         * Read in the statuses, using a single bulk read if possible
         * in order to reduce the I/O overheads.
         */
        if (!map->use_single_read && map->reg_stride == 1 &&
            data->irq_reg_stride == 1) {
                u8 *buf8 = data->status_reg_buf;
                u16 *buf16 = data->status_reg_buf;
                u32 *buf32 = data->status_reg_buf;

                BUG_ON(!data->status_reg_buf);

                ret = regmap_bulk_read(map, chip->status_base,
                                       data->status_reg_buf,
                                       chip->num_regs);
                if (ret != 0) {
                        dev_err(map->dev, "Failed to read IRQ status: %d\n",
                                ret);
                        return IRQ_NONE;
                }

                for (i = 0; i < data->chip->num_regs; i++) {
                        switch (map->format.val_bytes) {
                        case 1:
                                data->status_buf[i] = buf8[i];
                                break;
                        case 2:
                                data->status_buf[i] = buf16[i];
                                break;
                        case 4:
                                data->status_buf[i] = buf32[i];
                                break;
                        default:
                                BUG();
                                return IRQ_NONE;
                        }
                }

        } else {
                for (i = 0; i < data->chip->num_regs; i++) {
                        ret = regmap_read(map, chip->status_base +
                                          (i * map->reg_stride
                                           * data->irq_reg_stride),
                                          &data->status_buf[i]);

                        if (ret != 0) {
                                dev_err(map->dev,
                                        "Failed to read IRQ status: %d\n",
                                        ret);
                                if (chip->runtime_pm)
                                        pm_runtime_put(map->dev);
                                return IRQ_NONE;
                        }
                }
        }

        /*
         * Ignore masked IRQs and ack if we need to; we ack early so
         * there is no race between handling and acknowleding the
         * interrupt.  We assume that typically few of the interrupts
         * will fire simultaneously so don't worry about overhead from
         * doing a write per register.
         */
        for (i = 0; i < data->chip->num_regs; i++) {
                data->status_buf[i] &= ~data->mask_buf[i];

                if (data->status_buf[i] && (chip->ack_base || chip->use_ack)) {
                        reg = chip->ack_base +
                                (i * map->reg_stride * data->irq_reg_stride);
                        ret = regmap_write(map, reg, data->status_buf[i]);
                        if (ret != 0)
                                dev_err(map->dev, "Failed to ack 0x%x: %d\n",
                                        reg, ret);
                }
        }

        for (i = 0; i < chip->num_irqs; i++) {
                if (data->status_buf[chip->irqs[i].reg_offset /
                                     map->reg_stride] & chip->irqs[i].mask) {
                        handle_nested_irq(irq_find_mapping(data->domain, i));
                        handled = true;
                }
        }

        if (chip->runtime_pm)
                pm_runtime_put(map->dev);

        if (handled)
                return IRQ_HANDLED;
        else
                return IRQ_NONE;
}

static int regmap_irq_map(struct irq_domain *h, unsigned int virq,
                          irq_hw_number_t hw)
{
        struct regmap_irq_chip_data *data = h->host_data;

        irq_set_chip_data(virq, data);
        irq_set_chip(virq, &data->irq_chip);
        irq_set_nested_thread(virq, 1);
        irq_set_noprobe(virq);

        return 0;
}

static const struct irq_domain_ops regmap_domain_ops = {
        .map    = regmap_irq_map,
        .xlate  = irq_domain_xlate_twocell,
};

/**
 * regmap_add_irq_chip(): Use standard regmap IRQ controller handling
 *
 * map:       The regmap for the device.
 * irq:       The IRQ the device uses to signal interrupts
 * irq_flags: The IRQF_ flags to use for the primary interrupt.
 * chip:      Configuration for the interrupt controller.
 * data:      Runtime data structure for the controller, allocated on success
 *
 * Returns 0 on success or an errno on failure.
 *
 * In order for this to be efficient the chip really should use a
 * register cache.  The chip driver is responsible for restoring the
 * register values used by the IRQ controller over suspend and resume.
 */
int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
                        int irq_base, const struct regmap_irq_chip *chip,
                        struct regmap_irq_chip_data **data)
{
        struct regmap_irq_chip_data *d;
        int i;
        int ret = -ENOMEM;
        u32 reg;
        u32 unmask_offset;

        if (chip->num_regs <= 0)
                return -EINVAL;

        for (i = 0; i < chip->num_irqs; i++) {
                if (chip->irqs[i].reg_offset % map->reg_stride)
                        return -EINVAL;
                if (chip->irqs[i].reg_offset / map->reg_stride >=
                    chip->num_regs)
                        return -EINVAL;
        }

        if (irq_base) {
                irq_base = irq_alloc_descs(irq_base, 0, chip->num_irqs, 0);
                if (irq_base < 0) {
                        dev_warn(map->dev, "Failed to allocate IRQs: %d\n",
                                 irq_base);
                        return irq_base;
                }
        }

        d = kzalloc(sizeof(*d), GFP_KERNEL);
        if (!d)
                return -ENOMEM;

        d->status_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
                                GFP_KERNEL);
        if (!d->status_buf)
                goto err_alloc;

        d->mask_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
                              GFP_KERNEL);
        if (!d->mask_buf)
                goto err_alloc;

        d->mask_buf_def = kzalloc(sizeof(unsigned int) * chip->num_regs,
                                  GFP_KERNEL);
        if (!d->mask_buf_def)
                goto err_alloc;

        if (chip->wake_base) {
                d->wake_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
                                      GFP_KERNEL);
                if (!d->wake_buf)
                        goto err_alloc;
        }

        d->irq_chip = regmap_irq_chip;
        d->irq_chip.name = chip->name;
        d->irq = irq;
        d->map = map;
        d->chip = chip;
        d->irq_base = irq_base;

        if (chip->irq_reg_stride)
                d->irq_reg_stride = chip->irq_reg_stride;
        else
                d->irq_reg_stride = 1;

        if (!map->use_single_read && map->reg_stride == 1 &&
            d->irq_reg_stride == 1) {
                d->status_reg_buf = kmalloc(map->format.val_bytes *
                                            chip->num_regs, GFP_KERNEL);
                if (!d->status_reg_buf)
                        goto err_alloc;
        }

        mutex_init(&d->lock);

        for (i = 0; i < chip->num_irqs; i++)
                d->mask_buf_def[chip->irqs[i].reg_offset / map->reg_stride]
                        |= chip->irqs[i].mask;

        /* Mask all the interrupts by default */
        for (i = 0; i < chip->num_regs; i++) {
                d->mask_buf[i] = d->mask_buf_def[i];
                reg = chip->mask_base +
                        (i * map->reg_stride * d->irq_reg_stride);
                if (chip->mask_invert)
                        ret = regmap_update_bits(map, reg,
                                         d->mask_buf[i], ~d->mask_buf[i]);
                else if (d->chip->unmask_base) {
                        unmask_offset = d->chip->unmask_base -
                                        d->chip->mask_base;
                        ret = regmap_update_bits(d->map,
                                        reg + unmask_offset,
                                        d->mask_buf[i],
                                        d->mask_buf[i]);
                } else
                        ret = regmap_update_bits(map, reg,
                                         d->mask_buf[i], d->mask_buf[i]);
                if (ret != 0) {
                        dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
                                reg, ret);
                        goto err_alloc;
                }

                if (!chip->init_ack_masked)
                        continue;

                /* Ack masked but set interrupts */
                reg = chip->status_base +
                        (i * map->reg_stride * d->irq_reg_stride);
                ret = regmap_read(map, reg, &d->status_buf[i]);
                if (ret != 0) {
                        dev_err(map->dev, "Failed to read IRQ status: %d\n",
                                ret);
                        goto err_alloc;
                }

                if (d->status_buf[i] && (chip->ack_base || chip->use_ack)) {
                        reg = chip->ack_base +
                                (i * map->reg_stride * d->irq_reg_stride);
                        if (chip->ack_invert)
                                ret = regmap_write(map, reg,
                                        ~(d->status_buf[i] & d->mask_buf[i]));
                        else
                                ret = regmap_write(map, reg,
                                        d->status_buf[i] & d->mask_buf[i]);
                        if (ret != 0) {
                                dev_err(map->dev, "Failed to ack 0x%x: %d\n",
                                        reg, ret);
                                goto err_alloc;
                        }
                }
        }

        /* Wake is disabled by default */
        if (d->wake_buf) {
                for (i = 0; i < chip->num_regs; i++) {
                        d->wake_buf[i] = d->mask_buf_def[i];
                        reg = chip->wake_base +
                                (i * map->reg_stride * d->irq_reg_stride);

                        if (chip->wake_invert)
                                ret = regmap_update_bits(map, reg,
                                                         d->mask_buf_def[i],
                                                         0);
                        else
                                ret = regmap_update_bits(map, reg,
                                                         d->mask_buf_def[i],
                                                         d->wake_buf[i]);
                        if (ret != 0) {
                                dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
                                        reg, ret);
                                goto err_alloc;
                        }
                }
        }

        if (irq_base)
                d->domain = irq_domain_add_legacy(map->dev->of_node,
                                                  chip->num_irqs, irq_base, 0,
                                                  &regmap_domain_ops, d);
        else
                d->domain = irq_domain_add_linear(map->dev->of_node,
                                                  chip->num_irqs,
                                                  &regmap_domain_ops, d);
        if (!d->domain) {
                dev_err(map->dev, "Failed to create IRQ domain\n");
                ret = -ENOMEM;
                goto err_alloc;
        }

        ret = request_threaded_irq(irq, NULL, regmap_irq_thread,
                                   irq_flags | IRQF_ONESHOT,
                                   chip->name, d);
        if (ret != 0) {
                dev_err(map->dev, "Failed to request IRQ %d for %s: %d\n",
                        irq, chip->name, ret);
                goto err_domain;
        }

        *data = d;

        return 0;

err_domain:
        /* Should really dispose of the domain but... */
err_alloc:
        kfree(d->wake_buf);
        kfree(d->mask_buf_def);
        kfree(d->mask_buf);
        kfree(d->status_buf);
        kfree(d->status_reg_buf);
        kfree(d);
        return ret;
}
EXPORT_SYMBOL_GPL(regmap_add_irq_chip);

/**
 * regmap_del_irq_chip(): Stop interrupt handling for a regmap IRQ chip
 *
 * @irq: Primary IRQ for the device
 * @d:   regmap_irq_chip_data allocated by regmap_add_irq_chip()
 */
void regmap_del_irq_chip(int irq, struct regmap_irq_chip_data *d)
{
        if (!d)
                return;

        free_irq(irq, d);
        irq_domain_remove(d->domain);
        kfree(d->wake_buf);
        kfree(d->mask_buf_def);
        kfree(d->mask_buf);
        kfree(d->status_reg_buf);
        kfree(d->status_buf);
        kfree(d);
}
EXPORT_SYMBOL_GPL(regmap_del_irq_chip);

/**
 * regmap_irq_chip_get_base(): Retrieve interrupt base for a regmap IRQ chip
 *
 * Useful for drivers to request their own IRQs.
 *
 * @data: regmap_irq controller to operate on.
 */
int regmap_irq_chip_get_base(struct regmap_irq_chip_data *data)
{
        WARN_ON(!data->irq_base);
        return data->irq_base;
}
EXPORT_SYMBOL_GPL(regmap_irq_chip_get_base);

/**
 * regmap_irq_get_virq(): Map an interrupt on a chip to a virtual IRQ
 *
 * Useful for drivers to request their own IRQs.
 *
 * @data: regmap_irq controller to operate on.
 * @irq: index of the interrupt requested in the chip IRQs
 */
int regmap_irq_get_virq(struct regmap_irq_chip_data *data, int irq)
{
        /* Handle holes in the IRQ list */
        if (!data->chip->irqs[irq].mask)
                return -EINVAL;

        return irq_create_mapping(data->domain, irq);
}
EXPORT_SYMBOL_GPL(regmap_irq_get_virq);

/**
 * regmap_irq_get_domain(): Retrieve the irq_domain for the chip
 *
 * Useful for drivers to request their own IRQs and for integration
 * with subsystems.  For ease of integration NULL is accepted as a
 * domain, allowing devices to just call this even if no domain is
 * allocated.
 *
 * @data: regmap_irq controller to operate on.
 */
struct irq_domain *regmap_irq_get_domain(struct regmap_irq_chip_data *data)
{
        if (data)
                return data->domain;
        else
                return NULL;
}
EXPORT_SYMBOL_GPL(regmap_irq_get_domain);