From a2d21848d9211dad5e786aa7368709ca8938834e Mon Sep 17 00:00:00 2001 From: Matti Vaittinen Date: Tue, 22 Jan 2019 11:42:24 +0200 Subject: regmap: regmap-irq: Add main status register support There is bunch of devices with multiple logical blocks which can generate interrupts. It's not a rare case that the interrupt reason registers are arranged so that there is own status/ack/mask register for each logical block. In some devices there is also a 'main interrupt register(s)' which can indicate what sub blocks have interrupts pending. When such a device is connected via slow bus like i2c the main part of interrupt handling latency can be caused by bus accesses. On systems where it is expected that only one (or few) sub blocks have active interrupts we can reduce the latency by only reading the main register and those sub registers which have active interrupts. Support this with regmap-irq for simple cases where main register does not require acking or masking. Signed-off-by: Matti Vaittinen Signed-off-by: Mark Brown --- drivers/base/regmap/regmap-irq.c | 99 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 95 insertions(+), 4 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c index 1bd1145ad8b5..22778e9501ff 100644 --- a/drivers/base/regmap/regmap-irq.c +++ b/drivers/base/regmap/regmap-irq.c @@ -35,6 +35,7 @@ struct regmap_irq_chip_data { int wake_count; void *status_reg_buf; + unsigned int *main_status_buf; unsigned int *status_buf; unsigned int *mask_buf; unsigned int *mask_buf_def; @@ -326,6 +327,33 @@ static const struct irq_chip regmap_irq_chip = { .irq_set_wake = regmap_irq_set_wake, }; +static inline int read_sub_irq_data(struct regmap_irq_chip_data *data, + unsigned int b) +{ + const struct regmap_irq_chip *chip = data->chip; + struct regmap *map = data->map; + struct regmap_irq_sub_irq_map *subreg; + int i, ret = 0; + + if (!chip->sub_reg_offsets) { + /* Assume linear mapping */ + ret = regmap_read(map, chip->status_base + + (b * map->reg_stride * data->irq_reg_stride), + &data->status_buf[b]); + } else { + subreg = &chip->sub_reg_offsets[b]; + for (i = 0; i < subreg->num_regs; i++) { + unsigned int offset = subreg->offset[i]; + + ret = regmap_read(map, chip->status_base + offset, + &data->status_buf[offset]); + if (ret) + break; + } + } + return ret; +} + static irqreturn_t regmap_irq_thread(int irq, void *d) { struct regmap_irq_chip_data *data = d; @@ -349,11 +377,65 @@ static irqreturn_t regmap_irq_thread(int irq, void *d) } /* - * Read in the statuses, using a single bulk read if possible - * in order to reduce the I/O overheads. + * Read only registers with active IRQs if the chip has 'main status + * register'. Else 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) { + + if (chip->num_main_regs) { + unsigned int max_main_bits; + unsigned long size; + + size = chip->num_regs * sizeof(unsigned int); + + max_main_bits = (chip->num_main_status_bits) ? + chip->num_main_status_bits : chip->num_regs; + /* Clear the status buf as we don't read all status regs */ + memset(data->status_buf, 0, size); + + /* We could support bulk read for main status registers + * but I don't expect to see devices with really many main + * status registers so let's only support single reads for the + * sake of simplicity. and add bulk reads only if needed + */ + for (i = 0; i < chip->num_main_regs; i++) { + ret = regmap_read(map, chip->main_status + + (i * map->reg_stride + * data->irq_reg_stride), + &data->main_status_buf[i]); + if (ret) { + dev_err(map->dev, + "Failed to read IRQ status %d\n", + ret); + goto exit; + } + } + + /* Read sub registers with active IRQs */ + for (i = 0; i < chip->num_main_regs; i++) { + unsigned int b; + const unsigned long mreg = data->main_status_buf[i]; + + for_each_set_bit(b, &mreg, map->format.val_bytes * 8) { + if (i * map->format.val_bytes * 8 + b > + max_main_bits) + break; + ret = read_sub_irq_data(data, b); + + if (ret != 0) { + dev_err(map->dev, + "Failed to read IRQ status %d\n", + ret); + if (chip->runtime_pm) + pm_runtime_put(map->dev); + goto exit; + } + } + + } + } else 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; @@ -518,6 +600,15 @@ int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags, if (!d) return -ENOMEM; + if (chip->num_main_regs) { + d->main_status_buf = kcalloc(chip->num_main_regs, + sizeof(unsigned int), + GFP_KERNEL); + + if (!d->main_status_buf) + goto err_alloc; + } + d->status_buf = kcalloc(chip->num_regs, sizeof(unsigned int), GFP_KERNEL); if (!d->status_buf) -- cgit From 435bba0f11f06789be59757719c161915e92f889 Mon Sep 17 00:00:00 2001 From: Mathieu Malaterre Date: Thu, 24 Jan 2019 19:06:24 +0100 Subject: regmap: Remove attribute packed from struct 'regcache_rbtree_node' On one hand commit 28644c809f44 ("regmap: Add the rbtree cache support") added 'regcache_rbtree_node' as packed structure, while on the other hand commit e977145aeaad ("[RBTREE] Add explicit alignment to sizeof(long) for struct rb_node.") declared struct 'rb_node' as aligned. Solve the ambiguity of placing aligned structure in a packed one by removing the packed attribute from struct. This seems to be the behavior of gcc anyway. This removes the following warning (W=1): drivers/base/regmap/regcache-rbtree.c:36:1: warning: alignment 1 of 'struct regcache_rbtree_node' is less than 4 [-Wpacked-not-aligned] Cc: Dimitris Papastamos Cc: David Woodhouse Signed-off-by: Mathieu Malaterre Signed-off-by: Mark Brown --- drivers/base/regmap/regcache-rbtree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/base') diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c index 2e8f0144f9ab..9cbb4b0cd01b 100644 --- a/drivers/base/regmap/regcache-rbtree.c +++ b/drivers/base/regmap/regcache-rbtree.c @@ -33,7 +33,7 @@ struct regcache_rbtree_node { unsigned int blklen; /* the actual rbtree node holding this block */ struct rb_node node; -} __attribute__ ((packed)); +}; struct regcache_rbtree_ctx { struct rb_root root; -- cgit