regmap: Updates for v4.4

Quite a few new features for regmap this time, mostly expanding things
 around the edges of the existing functionality to cover more devices
 rather than thinsg with wide applicability:
 
  - Support for offload of the update_bits() operation to hardware where
    devices implement bit level access.
  - Support for a few extra operations that need scratch buffers on
    fast_io devices where we can't sleep.
  - Expanded the feature set of regmap_irq to cope with some extra
    register layouts.
  - Cleanups to the debugfs code.
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Merge tag 'regmap-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap updates from Mark Brown:
 "Quite a few new features for regmap this time, mostly expanding things
  around the edges of the existing functionality to cover more devices
  rather than thinsg with wide applicability:

   - Support for offload of the update_bits() operation to hardware
     where devices implement bit level access.
   - Support for a few extra operations that need scratch buffers on
     fast_io devices where we can't sleep.
   - Expanded the feature set of regmap_irq to cope with some extra
     register layouts.
   - Cleanups to the debugfs code"

* tag 'regmap-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: Allow installing custom reg_update_bits function
  regmap: debugfs: simplify regmap_reg_ranges_read_file() slightly
  regmap: debugfs: use memcpy instead of snprintf
  regmap: debugfs: use snprintf return value in regmap_reg_ranges_read_file()
  regmap: Add generic macro to define regmap_irq
  regmap: debugfs: Remove scratch buffer for register length calculation
  regmap: irq: add ack_invert flag for chips using cleared bits as ack
  regmap: irq: add support for chips who have separate unmask registers
  regmap: Allocate buffers with GFP_ATOMIC when fast_io == true

drivers/base/regmap/internal.h

@@ -59,6 +59,7 @@ struct regmap {
 	regmap_lock lock;
 	regmap_unlock unlock;
 	void *lock_arg; /* This is passed to lock/unlock functions */
+	gfp_t alloc_flags;
 
 	struct device *dev; /* Device we do I/O on */
 	void *work_buf;     /* Scratch buffer used to format I/O */
@@ -98,6 +99,8 @@ struct regmap {
 
 	int (*reg_read)(void *context, unsigned int reg, unsigned int *val);
 	int (*reg_write)(void *context, unsigned int reg, unsigned int val);
+	int (*reg_update_bits)(void *context, unsigned int reg,
+			       unsigned int mask, unsigned int val);
 
 	bool defer_caching;
 

drivers/base/regmap/regmap-debugfs.c

@@ -30,7 +30,7 @@ static LIST_HEAD(regmap_debugfs_early_list);
 static DEFINE_MUTEX(regmap_debugfs_early_lock);
 
 /* Calculate the length of a fixed format  */
-static size_t regmap_calc_reg_len(int max_val, char *buf, size_t buf_size)
+static size_t regmap_calc_reg_len(int max_val)
 {
 	return snprintf(NULL, 0, "%x", max_val);
 }
@@ -173,8 +173,7 @@ static inline void regmap_calc_tot_len(struct regmap *map,
 {
 	/* Calculate the length of a fixed format  */
 	if (!map->debugfs_tot_len) {
-		map->debugfs_reg_len = regmap_calc_reg_len(map->max_register,
-							   buf, count);
+		map->debugfs_reg_len = regmap_calc_reg_len(map->max_register),
 		map->debugfs_val_len = 2 * map->format.val_bytes;
 		map->debugfs_tot_len = map->debugfs_reg_len +
 			map->debugfs_val_len + 3;      /* : \n */
@@ -338,6 +337,7 @@ static ssize_t regmap_reg_ranges_read_file(struct file *file,
 	char *buf;
 	char *entry;
 	int ret;
+	unsigned entry_len;
 
 	if (*ppos < 0 || !count)
 		return -EINVAL;
@@ -365,18 +365,15 @@ static ssize_t regmap_reg_ranges_read_file(struct file *file,
 	p = 0;
 	mutex_lock(&map->cache_lock);
 	list_for_each_entry(c, &map->debugfs_off_cache, list) {
-		snprintf(entry, PAGE_SIZE, "%x-%x",
-			 c->base_reg, c->max_reg);
+		entry_len = snprintf(entry, PAGE_SIZE, "%x-%x\n",
+				     c->base_reg, c->max_reg);
 		if (p >= *ppos) {
-			if (buf_pos + 1 + strlen(entry) > count)
+			if (buf_pos + entry_len > count)
 				break;
-			snprintf(buf + buf_pos, count - buf_pos,
-				 "%s", entry);
-			buf_pos += strlen(entry);
-			buf[buf_pos] = '\n';
-			buf_pos++;
+			memcpy(buf + buf_pos, entry, entry_len);
+			buf_pos += entry_len;
 		}
-		p += strlen(entry) + 1;
+		p += entry_len;
 	}
 	mutex_unlock(&map->cache_lock);
 
@@ -420,7 +417,7 @@ static ssize_t regmap_access_read_file(struct file *file,
 		return -ENOMEM;
 
 	/* Calculate the length of a fixed format  */
-	reg_len = regmap_calc_reg_len(map->max_register, buf, count);
+	reg_len = regmap_calc_reg_len(map->max_register);
 	tot_len = reg_len + 10; /* ': R W V P\n' */
 
 	for (i = 0; i <= map->max_register; i += map->reg_stride) {

drivers/base/regmap/regmap-irq.c

@@ -63,6 +63,7 @@ static void regmap_irq_sync_unlock(struct irq_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);
@@ -79,12 +80,28 @@ static void regmap_irq_sync_unlock(struct irq_data *data)
 	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)
+		if (d->chip->mask_invert) {
 			ret = regmap_update_bits(d->map, reg,
 					 d->mask_buf_def[i], ~d->mask_buf[i]);
-		else
+		} 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);
@@ -116,7 +133,11 @@ static void regmap_irq_sync_unlock(struct irq_data *data)
 		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);
-			ret = regmap_write(map, reg, d->mask_buf[i]);
+			/* 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);
@@ -339,6 +360,7 @@ int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
 	int i;
 	int ret = -ENOMEM;
 	u32 reg;
+	u32 unmask_offset;
 
 	if (chip->num_regs <= 0)
 		return -EINVAL;
@@ -420,7 +442,14 @@ int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
 		if (chip->mask_invert)
 			ret = regmap_update_bits(map, reg,
 					 d->mask_buf[i], ~d->mask_buf[i]);
-		else
+		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) {
@@ -445,7 +474,11 @@ int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
 		if (d->status_buf[i] && (chip->ack_base || chip->use_ack)) {
 			reg = chip->ack_base +
 				(i * map->reg_stride * d->irq_reg_stride);
-			ret = regmap_write(map, reg,
+			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",

drivers/base/regmap/regmap.c

@@ -561,6 +561,16 @@ struct regmap *__regmap_init(struct device *dev,
 		}
 		map->lock_arg = map;
 	}
+
+	/*
+	 * When we write in fast-paths with regmap_bulk_write() don't allocate
+	 * scratch buffers with sleeping allocations.
+	 */
+	if ((bus && bus->fast_io) || config->fast_io)
+		map->alloc_flags = GFP_ATOMIC;
+	else
+		map->alloc_flags = GFP_KERNEL;
+
 	map->format.reg_bytes = DIV_ROUND_UP(config->reg_bits, 8);
 	map->format.pad_bytes = config->pad_bits / 8;
 	map->format.val_bytes = DIV_ROUND_UP(config->val_bits, 8);
@@ -619,6 +629,7 @@ struct regmap *__regmap_init(struct device *dev,
 		goto skip_format_initialization;
 	} else {
 		map->reg_read  = _regmap_bus_read;
+		map->reg_update_bits = bus->reg_update_bits;
 	}
 
 	reg_endian = regmap_get_reg_endian(bus, config);
@@ -1786,7 +1797,7 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
 		if (!val_count)
 			return -EINVAL;
 
-		wval = kmemdup(val, val_count * val_bytes, GFP_KERNEL);
+		wval = kmemdup(val, val_count * val_bytes, map->alloc_flags);
 		if (!wval) {
 			dev_err(map->dev, "Error in memory allocation\n");
 			return -ENOMEM;
@@ -2509,20 +2520,26 @@ static int _regmap_update_bits(struct regmap *map, unsigned int reg,
 	int ret;
 	unsigned int tmp, orig;
 
-	ret = _regmap_read(map, reg, &orig);
-	if (ret != 0)
-		return ret;
+	if (change)
+		*change = false;
 
-	tmp = orig & ~mask;
-	tmp |= val & mask;
-
-	if (force_write || (tmp != orig)) {
-		ret = _regmap_write(map, reg, tmp);
-		if (change)
+	if (regmap_volatile(map, reg) && map->reg_update_bits) {
+		ret = map->reg_update_bits(map->bus_context, reg, mask, val);
+		if (ret == 0 && change)
 			*change = true;
 	} else {
-		if (change)
-			*change = false;
+		ret = _regmap_read(map, reg, &orig);
+		if (ret != 0)
+			return ret;
+
+		tmp = orig & ~mask;
+		tmp |= val & mask;
+
+		if (force_write || (tmp != orig)) {
+			ret = _regmap_write(map, reg, tmp);
+			if (ret == 0 && change)
+				*change = true;
+		}
 	}
 
 	return ret;

include/linux/regmap.h

@@ -296,6 +296,8 @@ typedef int (*regmap_hw_reg_read)(void *context, unsigned int reg,
 				  unsigned int *val);
 typedef int (*regmap_hw_reg_write)(void *context, unsigned int reg,
 				   unsigned int val);
+typedef int (*regmap_hw_reg_update_bits)(void *context, unsigned int reg,
+					 unsigned int mask, unsigned int val);
 typedef struct regmap_async *(*regmap_hw_async_alloc)(void);
 typedef void (*regmap_hw_free_context)(void *context);
 
@@ -335,6 +337,7 @@ struct regmap_bus {
 	regmap_hw_gather_write gather_write;
 	regmap_hw_async_write async_write;
 	regmap_hw_reg_write reg_write;
+	regmap_hw_reg_update_bits reg_update_bits;
 	regmap_hw_read read;
 	regmap_hw_reg_read reg_read;
 	regmap_hw_free_context free_context;
@@ -791,6 +794,9 @@ struct regmap_irq {
 	unsigned int mask;
 };
 
+#define REGMAP_IRQ_REG(_irq, _off, _mask)		\
+	[_irq] = { .reg_offset = (_off), .mask = (_mask) }
+
 /**
  * Description of a generic regmap irq_chip.  This is not intended to
  * handle every possible interrupt controller, but it should handle a
@@ -800,6 +806,8 @@ struct regmap_irq {
  *
  * @status_base: Base status register address.
  * @mask_base:   Base mask register address.
+ * @unmask_base:  Base unmask register address. for chips who have
+ *                separate mask and unmask registers
  * @ack_base:    Base ack address. If zero then the chip is clear on read.
  *               Using zero value is possible with @use_ack bit.
  * @wake_base:   Base address for wake enables.  If zero unsupported.
@@ -807,6 +815,7 @@ struct regmap_irq {
  * @init_ack_masked: Ack all masked interrupts once during initalization.
  * @mask_invert: Inverted mask register: cleared bits are masked out.
  * @use_ack:     Use @ack register even if it is zero.
+ * @ack_invert:  Inverted ack register: cleared bits for ack.
  * @wake_invert: Inverted wake register: cleared bits are wake enabled.
  * @runtime_pm:  Hold a runtime PM lock on the device when accessing it.
  *
@@ -820,12 +829,14 @@ struct regmap_irq_chip {
 
 	unsigned int status_base;
 	unsigned int mask_base;
+	unsigned int unmask_base;
 	unsigned int ack_base;
 	unsigned int wake_base;
 	unsigned int irq_reg_stride;
 	bool init_ack_masked:1;
 	bool mask_invert:1;
 	bool use_ack:1;
+	bool ack_invert:1;
 	bool wake_invert:1;
 	bool runtime_pm:1;