Merge branch 'ib-pca953x' into devel

1 files changed, 302 insertions, 182 deletions

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 023a32cfac42..905dc1916883 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -20,6 +20,7 @@
 #include <linux/module.h>
 #include <linux/of_platform.h>
 #include <linux/platform_data/pca953x.h>
+#include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 
@@ -30,6 +31,8 @@
 #define PCA953X_INVERT		0x02
 #define PCA953X_DIRECTION	0x03
 
+#define REG_ADDR_MASK		0x3f
+#define REG_ADDR_EXT		0x40
 #define REG_ADDR_AI		0x80
 
 #define PCA957X_IN		0x00
@@ -58,7 +61,7 @@
 #define PCA_GPIO_MASK		0x00FF
 
 #define PCAL_GPIO_MASK		0x1f
-#define PCAL_PINCTRL_MASK	0xe0
+#define PCAL_PINCTRL_MASK	0x60
 
 #define PCA_INT			0x0100
 #define PCA_PCAL		0x0200
@@ -119,25 +122,27 @@ struct pca953x_reg_config {
 	int direction;
 	int output;
 	int input;
+	int invert;
 };
 
 static const struct pca953x_reg_config pca953x_regs = {
 	.direction = PCA953X_DIRECTION,
 	.output = PCA953X_OUTPUT,
 	.input = PCA953X_INPUT,
+	.invert = PCA953X_INVERT,
 };
 
 static const struct pca953x_reg_config pca957x_regs = {
 	.direction = PCA957X_CFG,
 	.output = PCA957X_OUT,
 	.input = PCA957X_IN,
+	.invert = PCA957X_INVRT,
 };
 
 struct pca953x_chip {
 	unsigned gpio_start;
-	u8 reg_output[MAX_BANK];
-	u8 reg_direction[MAX_BANK];
 	struct mutex i2c_lock;
+	struct regmap *regmap;
 
 #ifdef CONFIG_GPIO_PCA953X_IRQ
 	struct mutex irq_lock;
@@ -154,87 +159,177 @@ struct pca953x_chip {
 	struct regulator *regulator;
 
 	const struct pca953x_reg_config *regs;
-
-	int (*write_regs)(struct pca953x_chip *, int, u8 *);
-	int (*read_regs)(struct pca953x_chip *, int, u8 *);
 };
 
-static int pca953x_read_single(struct pca953x_chip *chip, int reg, u32 *val,
-				int off)
+static int pca953x_bank_shift(struct pca953x_chip *chip)
 {
-	int ret;
-	int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
-	int offset = off / BANK_SZ;
+	return fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
+}
 
-	ret = i2c_smbus_read_byte_data(chip->client,
-				(reg << bank_shift) + offset);
-	*val = ret;
+#define PCA953x_BANK_INPUT	BIT(0)
+#define PCA953x_BANK_OUTPUT	BIT(1)
+#define PCA953x_BANK_POLARITY	BIT(2)
+#define PCA953x_BANK_CONFIG	BIT(3)
 
-	if (ret < 0) {
-		dev_err(&chip->client->dev, "failed reading register\n");
-		return ret;
+#define PCA957x_BANK_INPUT	BIT(0)
+#define PCA957x_BANK_POLARITY	BIT(1)
+#define PCA957x_BANK_BUSHOLD	BIT(2)
+#define PCA957x_BANK_CONFIG	BIT(4)
+#define PCA957x_BANK_OUTPUT	BIT(5)
+
+#define PCAL9xxx_BANK_IN_LATCH	BIT(8 + 2)
+#define PCAL9xxx_BANK_IRQ_MASK	BIT(8 + 5)
+#define PCAL9xxx_BANK_IRQ_STAT	BIT(8 + 6)
+
+/*
+ * We care about the following registers:
+ * - Standard set, below 0x40, each port can be replicated up to 8 times
+ *   - PCA953x standard
+ *     Input port			0x00 + 0 * bank_size	R
+ *     Output port			0x00 + 1 * bank_size	RW
+ *     Polarity Inversion port		0x00 + 2 * bank_size	RW
+ *     Configuration port		0x00 + 3 * bank_size	RW
+ *   - PCA957x with mixed up registers
+ *     Input port			0x00 + 0 * bank_size	R
+ *     Polarity Inversion port		0x00 + 1 * bank_size	RW
+ *     Bus hold port			0x00 + 2 * bank_size	RW
+ *     Configuration port		0x00 + 4 * bank_size	RW
+ *     Output port			0x00 + 5 * bank_size	RW
+ *
+ * - Extended set, above 0x40, often chip specific.
+ *   - PCAL6524/PCAL9555A with custom PCAL IRQ handling:
+ *     Input latch register		0x40 + 2 * bank_size	RW
+ *     Interrupt mask register		0x40 + 5 * bank_size	RW
+ *     Interrupt status register	0x40 + 6 * bank_size	R
+ *
+ * - Registers with bit 0x80 set, the AI bit
+ *   The bit is cleared and the registers fall into one of the
+ *   categories above.
+ */
+
+static bool pca953x_check_register(struct pca953x_chip *chip, unsigned int reg,
+				   u32 checkbank)
+{
+	int bank_shift = pca953x_bank_shift(chip);
+	int bank = (reg & REG_ADDR_MASK) >> bank_shift;
+	int offset = reg & (BIT(bank_shift) - 1);
+
+	/* Special PCAL extended register check. */
+	if (reg & REG_ADDR_EXT) {
+		if (!(chip->driver_data & PCA_PCAL))
+			return false;
+		bank += 8;
 	}
 
-	return 0;
+	/* Register is not in the matching bank. */
+	if (!(BIT(bank) & checkbank))
+		return false;
+
+	/* Register is not within allowed range of bank. */
+	if (offset >= NBANK(chip))
+		return false;
+
+	return true;
 }
 
-static int pca953x_write_single(struct pca953x_chip *chip, int reg, u32 val,
-				int off)
+static bool pca953x_readable_register(struct device *dev, unsigned int reg)
 {
-	int ret;
-	int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
-	int offset = off / BANK_SZ;
+	struct pca953x_chip *chip = dev_get_drvdata(dev);
+	u32 bank;
 
-	ret = i2c_smbus_write_byte_data(chip->client,
-					(reg << bank_shift) + offset, val);
+	if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE) {
+		bank = PCA953x_BANK_INPUT | PCA953x_BANK_OUTPUT |
+		       PCA953x_BANK_POLARITY | PCA953x_BANK_CONFIG;
+	} else {
+		bank = PCA957x_BANK_INPUT | PCA957x_BANK_OUTPUT |
+		       PCA957x_BANK_POLARITY | PCA957x_BANK_CONFIG |
+		       PCA957x_BANK_BUSHOLD;
+	}
 
-	if (ret < 0) {
-		dev_err(&chip->client->dev, "failed writing register\n");
-		return ret;
+	if (chip->driver_data & PCA_PCAL) {
+		bank |= PCAL9xxx_BANK_IN_LATCH | PCAL9xxx_BANK_IRQ_MASK |
+			PCAL9xxx_BANK_IRQ_STAT;
 	}
 
-	return 0;
+	return pca953x_check_register(chip, reg, bank);
 }
 
-static int pca953x_write_regs_8(struct pca953x_chip *chip, int reg, u8 *val)
+static bool pca953x_writeable_register(struct device *dev, unsigned int reg)
 {
-	return i2c_smbus_write_byte_data(chip->client, reg, *val);
-}
+	struct pca953x_chip *chip = dev_get_drvdata(dev);
+	u32 bank;
 
-static int pca953x_write_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
-{
-	u16 word = get_unaligned((u16 *)val);
+	if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE) {
+		bank = PCA953x_BANK_OUTPUT | PCA953x_BANK_POLARITY |
+			PCA953x_BANK_CONFIG;
+	} else {
+		bank = PCA957x_BANK_OUTPUT | PCA957x_BANK_POLARITY |
+			PCA957x_BANK_CONFIG | PCA957x_BANK_BUSHOLD;
+	}
 
-	return i2c_smbus_write_word_data(chip->client, reg << 1, word);
+	if (chip->driver_data & PCA_PCAL)
+		bank |= PCAL9xxx_BANK_IN_LATCH | PCAL9xxx_BANK_IRQ_MASK;
+
+	return pca953x_check_register(chip, reg, bank);
 }
 
-static int pca957x_write_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
+static bool pca953x_volatile_register(struct device *dev, unsigned int reg)
 {
-	int ret;
+	struct pca953x_chip *chip = dev_get_drvdata(dev);
+	u32 bank;
 
-	ret = i2c_smbus_write_byte_data(chip->client, reg << 1, val[0]);
-	if (ret < 0)
-		return ret;
+	if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE)
+		bank = PCA953x_BANK_INPUT;
+	else
+		bank = PCA957x_BANK_INPUT;
+
+	if (chip->driver_data & PCA_PCAL)
+		bank |= PCAL9xxx_BANK_IRQ_STAT;
 
-	return i2c_smbus_write_byte_data(chip->client, (reg << 1) + 1, val[1]);
+	return pca953x_check_register(chip, reg, bank);
 }
 
-static int pca953x_write_regs_24(struct pca953x_chip *chip, int reg, u8 *val)
+const struct regmap_config pca953x_i2c_regmap = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.readable_reg = pca953x_readable_register,
+	.writeable_reg = pca953x_writeable_register,
+	.volatile_reg = pca953x_volatile_register,
+
+	.cache_type = REGCACHE_RBTREE,
+	.max_register = 0x7f,
+};
+
+static u8 pca953x_recalc_addr(struct pca953x_chip *chip, int reg, int off,
+			      bool write, bool addrinc)
 {
-	int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
+	int bank_shift = pca953x_bank_shift(chip);
 	int addr = (reg & PCAL_GPIO_MASK) << bank_shift;
 	int pinctrl = (reg & PCAL_PINCTRL_MASK) << 1;
+	u8 regaddr = pinctrl | addr | (off / BANK_SZ);
+
+	/* Single byte read doesn't need AI bit set. */
+	if (!addrinc)
+		return regaddr;
+
+	/* Chips with 24 and more GPIOs always support Auto Increment */
+	if (write && NBANK(chip) > 2)
+		regaddr |= REG_ADDR_AI;
 
-	return i2c_smbus_write_i2c_block_data(chip->client,
-					      pinctrl | addr | REG_ADDR_AI,
-					      NBANK(chip), val);
+	/* PCA9575 needs address-increment on multi-byte writes */
+	if (PCA_CHIP_TYPE(chip->driver_data) == PCA957X_TYPE)
+		regaddr |= REG_ADDR_AI;
+
+	return regaddr;
 }
 
 static int pca953x_write_regs(struct pca953x_chip *chip, int reg, u8 *val)
 {
-	int ret = 0;
+	u8 regaddr = pca953x_recalc_addr(chip, reg, 0, true, true);
+	int ret;
 
-	ret = chip->write_regs(chip, reg, val);
+	ret = regmap_bulk_write(chip->regmap, regaddr, val, NBANK(chip));
 	if (ret < 0) {
 		dev_err(&chip->client->dev, "failed writing register\n");
 		return ret;
@@ -243,42 +338,12 @@ static int pca953x_write_regs(struct pca953x_chip *chip, int reg, u8 *val)
 	return 0;
 }
 
-static int pca953x_read_regs_8(struct pca953x_chip *chip, int reg, u8 *val)
-{
-	int ret;
-
-	ret = i2c_smbus_read_byte_data(chip->client, reg);
-	*val = ret;
-
-	return ret;
-}
-
-static int pca953x_read_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
-{
-	int ret;
-
-	ret = i2c_smbus_read_word_data(chip->client, reg << 1);
-	put_unaligned(ret, (u16 *)val);
-
-	return ret;
-}
-
-static int pca953x_read_regs_24(struct pca953x_chip *chip, int reg, u8 *val)
-{
-	int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
-	int addr = (reg & PCAL_GPIO_MASK) << bank_shift;
-	int pinctrl = (reg & PCAL_PINCTRL_MASK) << 1;
-
-	return i2c_smbus_read_i2c_block_data(chip->client,
-					     pinctrl | addr | REG_ADDR_AI,
-					     NBANK(chip), val);
-}
-
 static int pca953x_read_regs(struct pca953x_chip *chip, int reg, u8 *val)
 {
+	u8 regaddr = pca953x_recalc_addr(chip, reg, 0, false, true);
 	int ret;
 
-	ret = chip->read_regs(chip, reg, val);
+	ret = regmap_bulk_read(chip->regmap, regaddr, val, NBANK(chip));
 	if (ret < 0) {
 		dev_err(&chip->client->dev, "failed reading register\n");
 		return ret;
@@ -290,18 +355,13 @@ static int pca953x_read_regs(struct pca953x_chip *chip, int reg, u8 *val)
 static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
 {
 	struct pca953x_chip *chip = gpiochip_get_data(gc);
-	u8 reg_val;
+	u8 dirreg = pca953x_recalc_addr(chip, chip->regs->direction, off,
+					true, false);
+	u8 bit = BIT(off % BANK_SZ);
 	int ret;
 
 	mutex_lock(&chip->i2c_lock);
-	reg_val = chip->reg_direction[off / BANK_SZ] | (1u << (off % BANK_SZ));
-
-	ret = pca953x_write_single(chip, chip->regs->direction, reg_val, off);
-	if (ret)
-		goto exit;
-
-	chip->reg_direction[off / BANK_SZ] = reg_val;
-exit:
+	ret = regmap_write_bits(chip->regmap, dirreg, bit, bit);
 	mutex_unlock(&chip->i2c_lock);
 	return ret;
 }
@@ -310,31 +370,21 @@ static int pca953x_gpio_direction_output(struct gpio_chip *gc,
 		unsigned off, int val)
 {
 	struct pca953x_chip *chip = gpiochip_get_data(gc);
-	u8 reg_val;
+	u8 dirreg = pca953x_recalc_addr(chip, chip->regs->direction, off,
+					true, false);
+	u8 outreg = pca953x_recalc_addr(chip, chip->regs->output, off,
+					true, false);
+	u8 bit = BIT(off % BANK_SZ);
 	int ret;
 
 	mutex_lock(&chip->i2c_lock);
 	/* set output level */
-	if (val)
-		reg_val = chip->reg_output[off / BANK_SZ]
-			| (1u << (off % BANK_SZ));
-	else
-		reg_val = chip->reg_output[off / BANK_SZ]
-			& ~(1u << (off % BANK_SZ));
-
-	ret = pca953x_write_single(chip, chip->regs->output, reg_val, off);
+	ret = regmap_write_bits(chip->regmap, outreg, bit, val ? bit : 0);
 	if (ret)
 		goto exit;
 
-	chip->reg_output[off / BANK_SZ] = reg_val;
-
 	/* then direction */
-	reg_val = chip->reg_direction[off / BANK_SZ] & ~(1u << (off % BANK_SZ));
-	ret = pca953x_write_single(chip, chip->regs->direction, reg_val, off);
-	if (ret)
-		goto exit;
-
-	chip->reg_direction[off / BANK_SZ] = reg_val;
+	ret = regmap_write_bits(chip->regmap, dirreg, bit, 0);
 exit:
 	mutex_unlock(&chip->i2c_lock);
 	return ret;
@@ -343,11 +393,14 @@ exit:
 static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
 {
 	struct pca953x_chip *chip = gpiochip_get_data(gc);
+	u8 inreg = pca953x_recalc_addr(chip, chip->regs->input, off,
+				       true, false);
+	u8 bit = BIT(off % BANK_SZ);
 	u32 reg_val;
 	int ret;
 
 	mutex_lock(&chip->i2c_lock);
-	ret = pca953x_read_single(chip, chip->regs->input, &reg_val, off);
+	ret = regmap_read(chip->regmap, inreg, &reg_val);
 	mutex_unlock(&chip->i2c_lock);
 	if (ret < 0) {
 		/* NOTE:  diagnostic already emitted; that's all we should
@@ -357,45 +410,37 @@ static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
 		return 0;
 	}
 
-	return (reg_val & (1u << (off % BANK_SZ))) ? 1 : 0;
+	return !!(reg_val & bit);
 }
 
 static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
 {
 	struct pca953x_chip *chip = gpiochip_get_data(gc);
-	u8 reg_val;
-	int ret;
+	u8 outreg = pca953x_recalc_addr(chip, chip->regs->output, off,
+					true, false);
+	u8 bit = BIT(off % BANK_SZ);
 
 	mutex_lock(&chip->i2c_lock);
-	if (val)
-		reg_val = chip->reg_output[off / BANK_SZ]
-			| (1u << (off % BANK_SZ));
-	else
-		reg_val = chip->reg_output[off / BANK_SZ]
-			& ~(1u << (off % BANK_SZ));
-
-	ret = pca953x_write_single(chip, chip->regs->output, reg_val, off);
-	if (ret)
-		goto exit;
-
-	chip->reg_output[off / BANK_SZ] = reg_val;
-exit:
+	regmap_write_bits(chip->regmap, outreg, bit, val ? bit : 0);
 	mutex_unlock(&chip->i2c_lock);
 }
 
 static int pca953x_gpio_get_direction(struct gpio_chip *gc, unsigned off)
 {
 	struct pca953x_chip *chip = gpiochip_get_data(gc);
+	u8 dirreg = pca953x_recalc_addr(chip, chip->regs->direction, off,
+					true, false);
+	u8 bit = BIT(off % BANK_SZ);
 	u32 reg_val;
 	int ret;
 
 	mutex_lock(&chip->i2c_lock);
-	ret = pca953x_read_single(chip, chip->regs->direction, &reg_val, off);
+	ret = regmap_read(chip->regmap, dirreg, &reg_val);
 	mutex_unlock(&chip->i2c_lock);
 	if (ret < 0)
 		return ret;
 
-	return !!(reg_val & (1u << (off % BANK_SZ)));
+	return !!(reg_val & bit);
 }
 
 static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
@@ -403,14 +448,15 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
 {
 	struct pca953x_chip *chip = gpiochip_get_data(gc);
 	unsigned int bank_mask, bank_val;
-	int bank_shift, bank;
+	int bank;
 	u8 reg_val[MAX_BANK];
 	int ret;
 
-	bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
-
 	mutex_lock(&chip->i2c_lock);
-	memcpy(reg_val, chip->reg_output, NBANK(chip));
+	ret = pca953x_read_regs(chip, chip->regs->output, reg_val);
+	if (ret)
+		goto exit;
+
 	for (bank = 0; bank < NBANK(chip); bank++) {
 		bank_mask = mask[bank / sizeof(*mask)] >>
 			   ((bank % sizeof(*mask)) * 8);
@@ -422,13 +468,7 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
 		}
 	}
 
-	ret = i2c_smbus_write_i2c_block_data(chip->client,
-					     chip->regs->output << bank_shift,
-					     NBANK(chip), reg_val);
-	if (ret)
-		goto exit;
-
-	memcpy(chip->reg_output, reg_val, NBANK(chip));
+	pca953x_write_regs(chip, chip->regs->output, reg_val);
 exit:
 	mutex_unlock(&chip->i2c_lock);
 }
@@ -487,6 +527,10 @@ static void pca953x_irq_bus_sync_unlock(struct irq_data *d)
 	u8 new_irqs;
 	int level, i;
 	u8 invert_irq_mask[MAX_BANK];
+	int reg_direction[MAX_BANK];
+
+	regmap_bulk_read(chip->regmap, chip->regs->direction, reg_direction,
+			 NBANK(chip));
 
 	if (chip->driver_data & PCA_PCAL) {
 		/* Enable latch on interrupt-enabled inputs */
@@ -502,7 +546,7 @@ static void pca953x_irq_bus_sync_unlock(struct irq_data *d)
 	/* 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 &= ~chip->reg_direction[i];
+		new_irqs &= reg_direction[i];
 
 		while (new_irqs) {
 			level = __ffs(new_irqs);
@@ -567,6 +611,7 @@ static bool pca953x_irq_pending(struct pca953x_chip *chip, u8 *pending)
 	bool pending_seen = false;
 	bool trigger_seen = false;
 	u8 trigger[MAX_BANK];
+	int reg_direction[MAX_BANK];
 	int ret, i;
 
 	if (chip->driver_data & PCA_PCAL) {
@@ -597,8 +642,10 @@ static bool pca953x_irq_pending(struct pca953x_chip *chip, u8 *pending)
 		return false;
 
 	/* Remove output pins from the equation */
+	regmap_bulk_read(chip->regmap, chip->regs->direction, reg_direction,
+			 NBANK(chip));
 	for (i = 0; i < NBANK(chip); i++)
-		cur_stat[i] &= chip->reg_direction[i];
+		cur_stat[i] &= reg_direction[i];
 
 	memcpy(old_stat, chip->irq_stat, NBANK(chip));
 
@@ -652,6 +699,7 @@ static int pca953x_irq_setup(struct pca953x_chip *chip,
 			     int irq_base)
 {
 	struct i2c_client *client = chip->client;
+	int reg_direction[MAX_BANK];
 	int ret, i;
 
 	if (client->irq && irq_base != -1
@@ -666,8 +714,10 @@ static int pca953x_irq_setup(struct pca953x_chip *chip,
 		 * interrupt.  We have to rely on the previous read for
 		 * this purpose.
 		 */
+		regmap_bulk_read(chip->regmap, chip->regs->direction,
+				 reg_direction, NBANK(chip));
 		for (i = 0; i < NBANK(chip); i++)
-			chip->irq_stat[i] &= chip->reg_direction[i];
+			chip->irq_stat[i] &= reg_direction[i];
 		mutex_init(&chip->irq_lock);
 
 		ret = devm_request_threaded_irq(&client->dev,
@@ -715,20 +765,19 @@ static int pca953x_irq_setup(struct pca953x_chip *chip,
 }
 #endif
 
-static int device_pca953x_init(struct pca953x_chip *chip, u32 invert)
+static int device_pca95xx_init(struct pca953x_chip *chip, u32 invert)
 {
 	int ret;
 	u8 val[MAX_BANK];
 
-	chip->regs = &pca953x_regs;
-
-	ret = pca953x_read_regs(chip, chip->regs->output, chip->reg_output);
-	if (ret)
+	ret = regcache_sync_region(chip->regmap, chip->regs->output,
+				   chip->regs->output + NBANK(chip));
+	if (ret != 0)
 		goto out;
 
-	ret = pca953x_read_regs(chip, chip->regs->direction,
-				chip->reg_direction);
-	if (ret)
+	ret = regcache_sync_region(chip->regmap, chip->regs->direction,
+				   chip->regs->direction + NBANK(chip));
+	if (ret != 0)
 		goto out;
 
 	/* set platform specific polarity inversion */
@@ -737,7 +786,7 @@ static int device_pca953x_init(struct pca953x_chip *chip, u32 invert)
 	else
 		memset(val, 0, NBANK(chip));
 
-	ret = pca953x_write_regs(chip, PCA953X_INVERT, val);
+	ret = pca953x_write_regs(chip, chip->regs->invert, val);
 out:
 	return ret;
 }
@@ -747,22 +796,7 @@ static int device_pca957x_init(struct pca953x_chip *chip, u32 invert)
 	int ret;
 	u8 val[MAX_BANK];
 
-	chip->regs = &pca957x_regs;
-
-	ret = pca953x_read_regs(chip, chip->regs->output, chip->reg_output);
-	if (ret)
-		goto out;
-	ret = pca953x_read_regs(chip, chip->regs->direction,
-				chip->reg_direction);
-	if (ret)
-		goto out;
-
-	/* set platform specific polarity inversion */
-	if (invert)
-		memset(val, 0xFF, NBANK(chip));
-	else
-		memset(val, 0, NBANK(chip));
-	ret = pca953x_write_regs(chip, PCA957X_INVRT, val);
+	ret = device_pca95xx_init(chip, invert);
 	if (ret)
 		goto out;
 
@@ -853,6 +887,16 @@ static int pca953x_probe(struct i2c_client *client,
 		}
 	}
 
+	i2c_set_clientdata(client, chip);
+
+	chip->regmap = devm_regmap_init_i2c(client, &pca953x_i2c_regmap);
+	if (IS_ERR(chip->regmap)) {
+		ret = PTR_ERR(chip->regmap);
+		goto err_exit;
+	}
+
+	regcache_mark_dirty(chip->regmap);
+
 	mutex_init(&chip->i2c_lock);
 	/*
 	 * In case we have an i2c-mux controlled by a GPIO provided by an
@@ -878,24 +922,13 @@ static int pca953x_probe(struct i2c_client *client,
 	 */
 	pca953x_setup_gpio(chip, chip->driver_data & PCA_GPIO_MASK);
 
-	if (chip->gpio_chip.ngpio <= 8) {
-		chip->write_regs = pca953x_write_regs_8;
-		chip->read_regs = pca953x_read_regs_8;
-	} else if (chip->gpio_chip.ngpio >= 24) {
-		chip->write_regs = pca953x_write_regs_24;
-		chip->read_regs = pca953x_read_regs_24;
+	if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE) {
+		chip->regs = &pca953x_regs;
+		ret = device_pca95xx_init(chip, invert);
 	} else {
-		if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE)
-			chip->write_regs = pca953x_write_regs_16;
-		else
-			chip->write_regs = pca957x_write_regs_16;
-		chip->read_regs = pca953x_read_regs_16;
-	}
-
-	if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE)
-		ret = device_pca953x_init(chip, invert);
-	else
+		chip->regs = &pca957x_regs;
 		ret = device_pca957x_init(chip, invert);
+	}
 	if (ret)
 		goto err_exit;
 
@@ -914,7 +947,6 @@ static int pca953x_probe(struct i2c_client *client,
 			dev_warn(&client->dev, "setup failed, %d\n", ret);
 	}
 
-	i2c_set_clientdata(client, chip);
 	return 0;
 
 err_exit:
@@ -943,6 +975,91 @@ static int pca953x_remove(struct i2c_client *client)
 	return ret;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int pca953x_regcache_sync(struct device *dev)
+{
+	struct pca953x_chip *chip = dev_get_drvdata(dev);
+	int ret;
+
+	/*
+	 * The ordering between direction and output is important,
+	 * sync these registers first and only then sync the rest.
+	 */
+	ret = regcache_sync_region(chip->regmap, chip->regs->direction,
+				   chip->regs->direction + NBANK(chip));
+	if (ret != 0) {
+		dev_err(dev, "Failed to sync GPIO dir registers: %d\n", ret);
+		return ret;
+	}
+
+	ret = regcache_sync_region(chip->regmap, chip->regs->output,
+				   chip->regs->output + NBANK(chip));
+	if (ret != 0) {
+		dev_err(dev, "Failed to sync GPIO out registers: %d\n", ret);
+		return ret;
+	}
+
+#ifdef CONFIG_GPIO_PCA953X_IRQ
+	if (chip->driver_data & PCA_PCAL) {
+		ret = regcache_sync_region(chip->regmap, PCAL953X_IN_LATCH,
+					   PCAL953X_IN_LATCH + NBANK(chip));
+		if (ret != 0) {
+			dev_err(dev, "Failed to sync INT latch registers: %d\n",
+				ret);
+			return ret;
+		}
+
+		ret = regcache_sync_region(chip->regmap, PCAL953X_INT_MASK,
+					   PCAL953X_INT_MASK + NBANK(chip));
+		if (ret != 0) {
+			dev_err(dev, "Failed to sync INT mask registers: %d\n",
+				ret);
+			return ret;
+		}
+	}
+#endif
+
+	return 0;
+}
+
+static int pca953x_suspend(struct device *dev)
+{
+	struct pca953x_chip *chip = dev_get_drvdata(dev);
+
+	regcache_cache_only(chip->regmap, true);
+
+	regulator_disable(chip->regulator);
+
+	return 0;
+}
+
+static int pca953x_resume(struct device *dev)
+{
+	struct pca953x_chip *chip = dev_get_drvdata(dev);
+	int ret;
+
+	ret = regulator_enable(chip->regulator);
+	if (ret != 0) {
+		dev_err(dev, "Failed to enable regulator: %d\n", ret);
+		return 0;
+	}
+
+	regcache_cache_only(chip->regmap, false);
+	regcache_mark_dirty(chip->regmap);
+	ret = pca953x_regcache_sync(dev);
+	if (ret)
+		return ret;
+
+	ret = regcache_sync(chip->regmap);
+	if (ret != 0) {
+		dev_err(dev, "Failed to restore register map: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+#endif
+
 /* convenience to stop overlong match-table lines */
 #define OF_953X(__nrgpio, __int) (void *)(__nrgpio | PCA953X_TYPE | __int)
 #define OF_957X(__nrgpio, __int) (void *)(__nrgpio | PCA957X_TYPE | __int)
@@ -986,9 +1103,12 @@ static const struct of_device_id pca953x_dt_ids[] = {
 
 MODULE_DEVICE_TABLE(of, pca953x_dt_ids);
 
+static SIMPLE_DEV_PM_OPS(pca953x_pm_ops, pca953x_suspend, pca953x_resume);
+
 static struct i2c_driver pca953x_driver = {
 	.driver = {
 		.name	= "pca953x",
+		.pm	= &pca953x_pm_ops,
 		.of_match_table = pca953x_dt_ids,
 		.acpi_match_table = ACPI_PTR(pca953x_acpi_ids),
 	},