[patch 72/86] gpio: pca953x: convert to use bitmap API

[Andrew Morton <akpm@linux-foundation.org>]

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: gpio: pca953x: convert to use bitmap API

Instead of customized approach convert the driver to use bitmap API.

[andriy.shevchenko@linux.intel.com: reduce stack usage in couple of functions]
  Link: http://lkml.kernel.org/r/20191023153056.64262-1-andriy.shevchenko@linux.intel.com
Link: http://lkml.kernel.org/r/20191022172922.61232-11-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/gpio/gpio-pca953x.c |  164 ++++++++++++++--------------------
 1 file changed, 70 insertions(+), 94 deletions(-)

--- a/drivers/gpio/gpio-pca953x.c~gpio-pca953x-convert-to-use-bitmap-api
+++ a/drivers/gpio/gpio-pca953x.c
@@ -9,8 +9,7 @@
  */
 
 #include <linux/acpi.h>
-#include <linux/bits.h>
-#include <linux/bitops.h>
+#include <linux/bitmap.h>
 #include <linux/gpio/driver.h>
 #include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
@@ -116,6 +115,7 @@ MODULE_DEVICE_TABLE(acpi, pca953x_acpi_i
 
 #define MAX_BANK 5
 #define BANK_SZ 8
+#define MAX_LINE	(MAX_BANK * BANK_SZ)
 
 #define NBANK(chip) DIV_ROUND_UP(chip->gpio_chip.ngpio, BANK_SZ)
 
@@ -147,10 +147,10 @@ struct pca953x_chip {
 
 #ifdef CONFIG_GPIO_PCA953X_IRQ
 	struct mutex irq_lock;
-	u8 irq_mask[MAX_BANK];
-	u8 irq_stat[MAX_BANK];
-	u8 irq_trig_raise[MAX_BANK];
-	u8 irq_trig_fall[MAX_BANK];
+	DECLARE_BITMAP(irq_mask, MAX_LINE);
+	DECLARE_BITMAP(irq_stat, MAX_LINE);
+	DECLARE_BITMAP(irq_trig_raise, MAX_LINE);
+	DECLARE_BITMAP(irq_trig_fall, MAX_LINE);
 	struct irq_chip irq_chip;
 #endif
 	atomic_t wakeup_path;
@@ -334,12 +334,16 @@ static u8 pca953x_recalc_addr(struct pca
 	return regaddr;
 }
 
-static int pca953x_write_regs(struct pca953x_chip *chip, int reg, u8 *val)
+static int pca953x_write_regs(struct pca953x_chip *chip, int reg, unsigned long *val)
 {
 	u8 regaddr = pca953x_recalc_addr(chip, reg, 0, true, true);
-	int ret;
+	u8 value[MAX_BANK];
+	int i, ret;
+
+	for (i = 0; i < NBANK(chip); i++)
+		value[i] = bitmap_get_value8(val, i * BANK_SZ);
 
-	ret = regmap_bulk_write(chip->regmap, regaddr, val, NBANK(chip));
+	ret = regmap_bulk_write(chip->regmap, regaddr, value, NBANK(chip));
 	if (ret < 0) {
 		dev_err(&chip->client->dev, "failed writing register\n");
 		return ret;
@@ -348,17 +352,21 @@ static int pca953x_write_regs(struct pca
 	return 0;
 }
 
-static int pca953x_read_regs(struct pca953x_chip *chip, int reg, u8 *val)
+static int pca953x_read_regs(struct pca953x_chip *chip, int reg, unsigned long *val)
 {
 	u8 regaddr = pca953x_recalc_addr(chip, reg, 0, false, true);
-	int ret;
+	u8 value[MAX_BANK];
+	int i, ret;
 
-	ret = regmap_bulk_read(chip->regmap, regaddr, val, NBANK(chip));
+	ret = regmap_bulk_read(chip->regmap, regaddr, value, NBANK(chip));
 	if (ret < 0) {
 		dev_err(&chip->client->dev, "failed reading register\n");
 		return ret;
 	}
 
+	for (i = 0; i < NBANK(chip); i++)
+		bitmap_set_value8(val, value[i], i * BANK_SZ);
+
 	return 0;
 }
 
@@ -460,10 +468,7 @@ static void pca953x_gpio_set_multiple(st
 				      unsigned long *mask, unsigned long *bits)
 {
 	struct pca953x_chip *chip = gpiochip_get_data(gc);
-	unsigned long offset;
-	unsigned long bank_mask;
-	int bank;
-	u8 reg_val[MAX_BANK];
+	DECLARE_BITMAP(reg_val, MAX_LINE);
 	int ret;
 
 	mutex_lock(&chip->i2c_lock);
@@ -471,11 +476,7 @@ static void pca953x_gpio_set_multiple(st
 	if (ret)
 		goto exit;
 
-	for_each_set_clump8(offset, bank_mask, mask, gc->ngpio) {
-		bank = offset / 8;
-		reg_val[bank] &= ~bank_mask;
-		reg_val[bank] |= bitmap_get_value8(bits, offset) & bank_mask;
-	}
+	bitmap_replace(reg_val, reg_val, bits, mask, gc->ngpio);
 
 	pca953x_write_regs(chip, chip->regs->output, reg_val);
 exit:
@@ -602,10 +603,9 @@ static void pca953x_irq_bus_sync_unlock(
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct pca953x_chip *chip = gpiochip_get_data(gc);
-	u8 new_irqs;
-	int level, i;
-	u8 invert_irq_mask[MAX_BANK];
-	u8 reg_direction[MAX_BANK];
+	DECLARE_BITMAP(irq_mask, MAX_LINE);
+	DECLARE_BITMAP(reg_direction, MAX_LINE);
+	int level;
 
 	pca953x_read_regs(chip, chip->regs->direction, reg_direction);
 
@@ -613,25 +613,18 @@ static void pca953x_irq_bus_sync_unlock(
 		/* Enable latch on interrupt-enabled inputs */
 		pca953x_write_regs(chip, PCAL953X_IN_LATCH, chip->irq_mask);
 
-		for (i = 0; i < NBANK(chip); i++)
-			invert_irq_mask[i] = ~chip->irq_mask[i];
+		bitmap_complement(irq_mask, chip->irq_mask, gc->ngpio);
 
 		/* Unmask enabled interrupts */
-		pca953x_write_regs(chip, PCAL953X_INT_MASK, invert_irq_mask);
+		pca953x_write_regs(chip, PCAL953X_INT_MASK, irq_mask);
 	}
 
+	bitmap_or(irq_mask, chip->irq_trig_fall, chip->irq_trig_raise, gc->ngpio);
+	bitmap_and(irq_mask, irq_mask, reg_direction, gc->ngpio);
+
 	/* Look for any newly setup interrupt */
-	for (i = 0; i < NBANK(chip); i++) {
-		new_irqs = chip->irq_trig_fall[i] | chip->irq_trig_raise[i];
-		new_irqs &= reg_direction[i];
-
-		while (new_irqs) {
-			level = __ffs(new_irqs);
-			pca953x_gpio_direction_input(&chip->gpio_chip,
-							level + (BANK_SZ * i));
-			new_irqs &= ~(1 << level);
-		}
-	}
+	for_each_set_bit(level, irq_mask, gc->ngpio)
+		pca953x_gpio_direction_input(&chip->gpio_chip, level);
 
 	mutex_unlock(&chip->irq_lock);
 }
@@ -672,15 +665,15 @@ static void pca953x_irq_shutdown(struct
 	chip->irq_trig_fall[d->hwirq / BANK_SZ] &= ~mask;
 }
 
-static bool pca953x_irq_pending(struct pca953x_chip *chip, u8 *pending)
+static bool pca953x_irq_pending(struct pca953x_chip *chip, unsigned long *pending)
 {
-	u8 cur_stat[MAX_BANK];
-	u8 old_stat[MAX_BANK];
-	bool pending_seen = false;
-	bool trigger_seen = false;
-	u8 trigger[MAX_BANK];
-	u8 reg_direction[MAX_BANK];
-	int ret, i;
+	struct gpio_chip *gc = &chip->gpio_chip;
+	DECLARE_BITMAP(reg_direction, MAX_LINE);
+	DECLARE_BITMAP(old_stat, MAX_LINE);
+	DECLARE_BITMAP(cur_stat, MAX_LINE);
+	DECLARE_BITMAP(new_stat, MAX_LINE);
+	DECLARE_BITMAP(trigger, MAX_LINE);
+	int ret;
 
 	if (chip->driver_data & PCA_PCAL) {
 		/* Read the current interrupt status from the device */
@@ -693,16 +686,12 @@ static bool pca953x_irq_pending(struct p
 		if (ret)
 			return false;
 
-		for (i = 0; i < NBANK(chip); i++) {
-			/* Apply filter for rising/falling edge selection */
-			pending[i] = (~cur_stat[i] & chip->irq_trig_fall[i]) |
-				(cur_stat[i] & chip->irq_trig_raise[i]);
-			pending[i] &= trigger[i];
-			if (pending[i])
-				pending_seen = true;
-		}
+		/* Apply filter for rising/falling edge selection */
+		bitmap_replace(new_stat, chip->irq_trig_fall, chip->irq_trig_raise, cur_stat, gc->ngpio);
+
+		bitmap_and(pending, new_stat, trigger, gc->ngpio);
 
-		return pending_seen;
+		return !bitmap_empty(pending, gc->ngpio);
 	}
 
 	ret = pca953x_read_regs(chip, chip->regs->input, cur_stat);
@@ -711,51 +700,38 @@ static bool pca953x_irq_pending(struct p
 
 	/* Remove output pins from the equation */
 	pca953x_read_regs(chip, chip->regs->direction, reg_direction);
-	for (i = 0; i < NBANK(chip); i++)
-		cur_stat[i] &= reg_direction[i];
 
-	memcpy(old_stat, chip->irq_stat, NBANK(chip));
+	bitmap_copy(old_stat, chip->irq_stat, gc->ngpio);
 
-	for (i = 0; i < NBANK(chip); i++) {
-		trigger[i] = (cur_stat[i] ^ old_stat[i]) & chip->irq_mask[i];
-		if (trigger[i])
-			trigger_seen = true;
-	}
+	bitmap_and(new_stat, cur_stat, reg_direction, gc->ngpio);
+	bitmap_xor(cur_stat, new_stat, old_stat, gc->ngpio);
+	bitmap_and(trigger, cur_stat, chip->irq_mask, gc->ngpio);
 
-	if (!trigger_seen)
+	if (bitmap_empty(trigger, gc->ngpio))
 		return false;
 
-	memcpy(chip->irq_stat, cur_stat, NBANK(chip));
+	bitmap_copy(chip->irq_stat, new_stat, gc->ngpio);
 
-	for (i = 0; i < NBANK(chip); i++) {
-		pending[i] = (old_stat[i] & chip->irq_trig_fall[i]) |
-			(cur_stat[i] & chip->irq_trig_raise[i]);
-		pending[i] &= trigger[i];
-		if (pending[i])
-			pending_seen = true;
-	}
+	bitmap_and(cur_stat, chip->irq_trig_fall, old_stat, gc->ngpio);
+	bitmap_and(old_stat, chip->irq_trig_raise, new_stat, gc->ngpio);
+	bitmap_or(new_stat, old_stat, cur_stat, gc->ngpio);
+	bitmap_and(pending, new_stat, trigger, gc->ngpio);
 
-	return pending_seen;
+	return !bitmap_empty(pending, gc->ngpio);
 }
 
 static irqreturn_t pca953x_irq_handler(int irq, void *devid)
 {
 	struct pca953x_chip *chip = devid;
-	u8 pending[MAX_BANK];
-	u8 level;
-	int i;
+	struct gpio_chip *gc = &chip->gpio_chip;
+	DECLARE_BITMAP(pending, MAX_LINE);
+	int level;
 
 	if (!pca953x_irq_pending(chip, pending))
 		return IRQ_NONE;
 
-	for (i = 0; i < NBANK(chip); i++) {
-		while (pending[i]) {
-			level = __ffs(pending[i]);
-			handle_nested_irq(irq_find_mapping(chip->gpio_chip.irq.domain,
-							level + (BANK_SZ * i)));
-			pending[i] &= ~(1 << level);
-		}
-	}
+	for_each_set_bit(level, pending, gc->ngpio)
+		handle_nested_irq(irq_find_mapping(gc->irq.domain, level));
 
 	return IRQ_HANDLED;
 }
@@ -765,8 +741,9 @@ static int pca953x_irq_setup(struct pca9
 {
 	struct i2c_client *client = chip->client;
 	struct irq_chip *irq_chip = &chip->irq_chip;
-	u8 reg_direction[MAX_BANK];
-	int ret, i;
+	DECLARE_BITMAP(reg_direction, MAX_LINE);
+	DECLARE_BITMAP(irq_stat, MAX_LINE);
+	int ret;
 
 	if (!client->irq)
 		return 0;
@@ -777,7 +754,7 @@ static int pca953x_irq_setup(struct pca9
 	if (!(chip->driver_data & PCA_INT))
 		return 0;
 
-	ret = pca953x_read_regs(chip, chip->regs->input, chip->irq_stat);
+	ret = pca953x_read_regs(chip, chip->regs->input, irq_stat);
 	if (ret)
 		return ret;
 
@@ -787,8 +764,7 @@ static int pca953x_irq_setup(struct pca9
 	 * this purpose.
 	 */
 	pca953x_read_regs(chip, chip->regs->direction, reg_direction);
-	for (i = 0; i < NBANK(chip); i++)
-		chip->irq_stat[i] &= reg_direction[i];
+	bitmap_and(chip->irq_stat, irq_stat, reg_direction, chip->gpio_chip.ngpio);
 	mutex_init(&chip->irq_lock);
 
 	ret = devm_request_threaded_irq(&client->dev, client->irq,
@@ -840,8 +816,8 @@ static int pca953x_irq_setup(struct pca9
 
 static int device_pca95xx_init(struct pca953x_chip *chip, u32 invert)
 {
+	DECLARE_BITMAP(val, MAX_LINE);
 	int ret;
-	u8 val[MAX_BANK];
 
 	ret = regcache_sync_region(chip->regmap, chip->regs->output,
 				   chip->regs->output + NBANK(chip));
@@ -855,9 +831,9 @@ static int device_pca95xx_init(struct pc
 
 	/* set platform specific polarity inversion */
 	if (invert)
-		memset(val, 0xFF, NBANK(chip));
+		bitmap_fill(val, MAX_LINE);
 	else
-		memset(val, 0, NBANK(chip));
+		bitmap_zero(val, MAX_LINE);
 
 	ret = pca953x_write_regs(chip, chip->regs->invert, val);
 out:
@@ -866,8 +842,8 @@ out:
 
 static int device_pca957x_init(struct pca953x_chip *chip, u32 invert)
 {
+	DECLARE_BITMAP(val, MAX_LINE);
 	int ret;
-	u8 val[MAX_BANK];
 
 	ret = device_pca95xx_init(chip, invert);
 	if (ret)
_