diff options
Diffstat (limited to 'drivers/base/regmap/regmap-irq.c')
| -rw-r--r-- | drivers/base/regmap/regmap-irq.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c new file mode 100644 index 00000000000..428836fc583 --- /dev/null +++ b/drivers/base/regmap/regmap-irq.c @@ -0,0 +1,302 @@ +/* + * 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/export.h> +#include <linux/regmap.h> +#include <linux/irq.h> +#include <linux/interrupt.h> +#include <linux/slab.h> + +#include "internal.h" + +struct regmap_irq_chip_data { + struct mutex lock; + + struct regmap *map; + struct regmap_irq_chip *chip; + + int irq_base; + + void *status_reg_buf; + unsigned int *status_buf; + unsigned int *mask_buf; + unsigned int *mask_buf_def; +}; + +static inline const +struct regmap_irq *irq_to_regmap_irq(struct regmap_irq_chip_data *data, + int irq) +{ + return &data->chip->irqs[irq - data->irq_base]; +} + +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); + int i, 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++) { + ret = regmap_update_bits(d->map, d->chip->mask_base + i, + d->mask_buf_def[i], d->mask_buf[i]); + if (ret != 0) + dev_err(d->map->dev, "Failed to sync masks in %x\n", + d->chip->mask_base + i); + } + + 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); + const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->irq); + + d->mask_buf[irq_data->reg_offset] &= ~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); + const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->irq); + + d->mask_buf[irq_data->reg_offset] |= irq_data->mask; +} + +static struct irq_chip regmap_irq_chip = { + .name = "regmap", + .irq_bus_lock = regmap_irq_lock, + .irq_bus_sync_unlock = regmap_irq_sync_unlock, + .irq_disable = regmap_irq_disable, + .irq_enable = regmap_irq_enable, +}; + +static irqreturn_t regmap_irq_thread(int irq, void *d) +{ + struct regmap_irq_chip_data *data = d; + struct regmap_irq_chip *chip = data->chip; + struct regmap *map = data->map; + int ret, i; + u8 *buf8 = data->status_reg_buf; + u16 *buf16 = data->status_reg_buf; + u32 *buf32 = data->status_reg_buf; + bool handled = false; + + 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; + } + + /* + * 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++) { + 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; + } + + data->status_buf[i] &= ~data->mask_buf[i]; + + if (data->status_buf[i] && chip->ack_base) { + ret = regmap_write(map, chip->ack_base + i, + data->status_buf[i]); + if (ret != 0) + dev_err(map->dev, "Failed to ack 0x%x: %d\n", + chip->ack_base + i, ret); + } + } + + for (i = 0; i < chip->num_irqs; i++) { + if (data->status_buf[chip->irqs[i].reg_offset] & + chip->irqs[i].mask) { + handle_nested_irq(data->irq_base + i); + handled = true; + } + } + + if (handled) + return IRQ_HANDLED; + else + return IRQ_NONE; +} + +/** + * 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, struct regmap_irq_chip *chip, + struct regmap_irq_chip_data **data) +{ + struct regmap_irq_chip_data *d; + int cur_irq, i; + int ret = -ENOMEM; + + 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->status_reg_buf = kzalloc(map->format.val_bytes * chip->num_regs, + GFP_KERNEL); + if (!d->status_reg_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; + + d->map = map; + d->chip = chip; + d->irq_base = irq_base; + mutex_init(&d->lock); + + for (i = 0; i < chip->num_irqs; i++) + d->mask_buf_def[chip->irqs[i].reg_offset] + |= 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]; + ret = regmap_write(map, chip->mask_base + i, d->mask_buf[i]); + if (ret != 0) { + dev_err(map->dev, "Failed to set masks in 0x%x: %d\n", + chip->mask_base + i, ret); + goto err_alloc; + } + } + + /* Register them with genirq */ + for (cur_irq = irq_base; + cur_irq < chip->num_irqs + irq_base; + cur_irq++) { + irq_set_chip_data(cur_irq, d); + irq_set_chip_and_handler(cur_irq, ®map_irq_chip, + handle_edge_irq); + irq_set_nested_thread(cur_irq, 1); + + /* ARM needs us to explicitly flag the IRQ as valid + * and will set them noprobe when we do so. */ +#ifdef CONFIG_ARM + set_irq_flags(cur_irq, IRQF_VALID); +#else + irq_set_noprobe(cur_irq); +#endif + } + + ret = request_threaded_irq(irq, NULL, regmap_irq_thread, irq_flags, + chip->name, d); + if (ret != 0) { + dev_err(map->dev, "Failed to request IRQ %d: %d\n", irq, ret); + goto err_alloc; + } + + return 0; + +err_alloc: + kfree(d->mask_buf_def); + kfree(d->mask_buf); + kfree(d->status_reg_buf); + kfree(d->status_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); + 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) +{ + return data->irq_base; +} +EXPORT_SYMBOL_GPL(regmap_irq_chip_get_base); |