From f8beab2bb611d735767871e0e1a12dc6a0def7b1 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Fri, 28 Oct 2011 23:50:49 +0200 Subject: [PATCH 1/3] regmap: Add a reusable irq_chip for regmap based interrupt controllers There seem to be lots of regmap-using devices with very similar interrupt controllers with a small bank of interrupt registers and mask registers with an interrupt per bit. This won't cover everything but it's a good start. Each chip supplies a base for the status registers, a base for the mask registers, an optional base for writing acknowledgements (which may be the same as the status registers) and an array of bits within each of these register banks which indicate the interrupt. There is an assumption that the bit for each interrupt will be the same in each of the register bank. Signed-off-by: Mark Brown --- drivers/base/regmap/Kconfig | 3 + drivers/base/regmap/Makefile | 1 + drivers/base/regmap/regmap-irq.c | 284 +++++++++++++++++++++++++++++++ include/linux/regmap.h | 47 +++++ 4 files changed, 335 insertions(+) create mode 100644 drivers/base/regmap/regmap-irq.c diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig index 2fc6a66f39a..0f6c7fb418e 100644 --- a/drivers/base/regmap/Kconfig +++ b/drivers/base/regmap/Kconfig @@ -13,3 +13,6 @@ config REGMAP_I2C config REGMAP_SPI tristate + +config REGMAP_IRQ + bool diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile index 0573c8a9dac..ce2d18a6465 100644 --- a/drivers/base/regmap/Makefile +++ b/drivers/base/regmap/Makefile @@ -2,3 +2,4 @@ obj-$(CONFIG_REGMAP) += regmap.o regcache.o regcache-indexed.o regcache-rbtree.o obj-$(CONFIG_DEBUG_FS) += regmap-debugfs.o obj-$(CONFIG_REGMAP_I2C) += regmap-i2c.o obj-$(CONFIG_REGMAP_SPI) += regmap-spi.o +obj-$(CONFIG_REGMAP_IRQ) += regmap-irq.o diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c new file mode 100644 index 00000000000..bd54f63be9e --- /dev/null +++ b/drivers/base/regmap/regmap-irq.c @@ -0,0 +1,284 @@ +/* + * regmap based irq_chip + * + * Copyright 2011 Wolfson Microelectronics plc + * + * Author: Mark Brown + * + * 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 +#include +#include +#include +#include + +#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; + + 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); + } + } + + return IRQ_HANDLED; +} + +/** + * 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); diff --git a/include/linux/regmap.h b/include/linux/regmap.h index 690276a642c..bd54cecdfdf 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -144,4 +144,51 @@ int regcache_sync(struct regmap *map); void regcache_cache_only(struct regmap *map, bool enable); void regcache_cache_bypass(struct regmap *map, bool enable); +/** + * Description of an IRQ for the generic regmap irq_chip. + * + * @reg_offset: Offset of the status/mask register within the bank + * @mask: Mask used to flag/control the register. + */ +struct regmap_irq { + unsigned int reg_offset; + unsigned int mask; +}; + +/** + * Description of a generic regmap irq_chip. This is not intended to + * handle every possible interrupt controller, but it should handle a + * substantial proportion of those that are found in the wild. + * + * @name: Descriptive name for IRQ controller. + * + * @status_base: Base status register address. + * @mask_base: Base mask register address. + * @ack_base: Base ack address. If zero then the chip is clear on read. + * + * @num_regs: Number of registers in each control bank. + * @irqs: Descriptors for individual IRQs. Interrupt numbers are + * assigned based on the index in the array of the interrupt. + * @num_irqs: Number of descriptors. + */ +struct regmap_irq_chip { + const char *name; + + unsigned int status_base; + unsigned int mask_base; + unsigned int ack_base; + + int num_regs; + + const struct regmap_irq *irqs; + int num_irqs; +}; + +struct regmap_irq_chip_data; + +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); +void regmap_del_irq_chip(int irq, struct regmap_irq_chip_data *data); + #endif From 8ae0d7e8a918e9603748abe9b31984fc5d96abb3 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Wed, 26 Oct 2011 10:34:22 +0200 Subject: [PATCH 2/3] regmap: Track if the register cache is dirty and suppress unneeded syncs Allow drivers to optimise out the register cache sync if they didn't need to do one. If the hardware is desynced from the register cache (by power loss for example) then the driver should call regcache_mark_dirty() to let the core know about this. Signed-off-by: Mark Brown --- drivers/base/regmap/internal.h | 1 + drivers/base/regmap/regcache.c | 19 +++++++++++++++++++ drivers/base/regmap/regmap.c | 4 +++- include/linux/regmap.h | 1 + 4 files changed, 24 insertions(+), 1 deletion(-) diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h index 348ff02eb93..6483e0bda0c 100644 --- a/drivers/base/regmap/internal.h +++ b/drivers/base/regmap/internal.h @@ -74,6 +74,7 @@ struct regmap { struct reg_default *reg_defaults; const void *reg_defaults_raw; void *cache; + bool cache_dirty; }; struct regcache_ops { diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c index 666f6f5011d..6ab9f0384d8 100644 --- a/drivers/base/regmap/regcache.c +++ b/drivers/base/regmap/regcache.c @@ -241,6 +241,8 @@ int regcache_sync(struct regmap *map) map->cache_ops->name); name = map->cache_ops->name; trace_regcache_sync(map->dev, name, "start"); + if (!map->cache_dirty) + goto out; if (map->cache_ops->sync) { ret = map->cache_ops->sync(map); } else { @@ -290,6 +292,23 @@ void regcache_cache_only(struct regmap *map, bool enable) } EXPORT_SYMBOL_GPL(regcache_cache_only); +/** + * regcache_mark_dirty: Mark the register cache as dirty + * + * @map: map to mark + * + * Mark the register cache as dirty, for example due to the device + * having been powered down for suspend. If the cache is not marked + * as dirty then the cache sync will be suppressed. + */ +void regcache_mark_dirty(struct regmap *map) +{ + mutex_lock(&map->lock); + map->cache_dirty = true; + mutex_unlock(&map->lock); +} +EXPORT_SYMBOL_GPL(regcache_mark_dirty); + /** * regcache_cache_bypass: Put a register map into cache bypass mode * diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index bf441db1ee9..3aca18dbf36 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -306,8 +306,10 @@ int _regmap_write(struct regmap *map, unsigned int reg, ret = regcache_write(map, reg, val); if (ret != 0) return ret; - if (map->cache_only) + if (map->cache_only) { + map->cache_dirty = true; return 0; + } } trace_regmap_reg_write(map->dev, reg, val); diff --git a/include/linux/regmap.h b/include/linux/regmap.h index 690276a642c..32043a9749e 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -143,5 +143,6 @@ int regmap_update_bits(struct regmap *map, unsigned int reg, int regcache_sync(struct regmap *map); void regcache_cache_only(struct regmap *map, bool enable); void regcache_cache_bypass(struct regmap *map, bool enable); +void regcache_mark_dirty(struct regmap *map); #endif From 50b776fc71c13663eb7434f634f2b796de5c9885 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Wed, 2 Nov 2011 15:00:03 +0000 Subject: [PATCH 3/3] regmap: Rename LZO cache type to compressed Users probably don't care about the specific compression algorithm and we might want to use a different algorithm (snappy being the one I'm thinking of right now) so update the public interface to have a more generic name. Signed-off-by: Mark Brown --- drivers/base/regmap/regcache-lzo.c | 2 +- include/linux/regmap.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/base/regmap/regcache-lzo.c b/drivers/base/regmap/regcache-lzo.c index 066aeece362..854448d0929 100644 --- a/drivers/base/regmap/regcache-lzo.c +++ b/drivers/base/regmap/regcache-lzo.c @@ -351,7 +351,7 @@ static int regcache_lzo_sync(struct regmap *map) } struct regcache_ops regcache_lzo_ops = { - .type = REGCACHE_LZO, + .type = REGCACHE_COMPRESSED, .name = "lzo", .init = regcache_lzo_init, .exit = regcache_lzo_exit, diff --git a/include/linux/regmap.h b/include/linux/regmap.h index 32043a9749e..bebda1481f2 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -25,7 +25,7 @@ enum regcache_type { REGCACHE_NONE, REGCACHE_INDEXED, REGCACHE_RBTREE, - REGCACHE_LZO + REGCACHE_COMPRESSED }; /**