[PATCH v5 0/3] Migrate the PCIe-IDIO-24 and WS16C48 GPIO drivers to the regmap API

[PATCH v5 0/3] Migrate the PCIe-IDIO-24 and WS16C48 GPIO drivers to the regmap API

[William Breathitt Gray]

Changes in v5:
 - Refactor for map parameter removal from handle_mask_sync()
 - Cleanups and line wrappings to 100 characters rather than 80
 - Adjust to change mutex/spinlock_t type locks to raw_spin_lock_t type
 - Remove pex8311_intcsr table configurations as superfluous
 - Adjust to set pex8311_intcsr_regmap_config reg_base to
   PLX_PEX8311_PCI_LCS_INTCSR
 - Rename PAGE_FIELD_PAGE_* defines to POL_PAGE, ENAB_PAGE, and
   INT_ID_PAGE
Changes in v4:
 - Allocate idio24gpio before using it in idio_24_probe()
Changes in v3:
 - Drop map from set_type_config() parameter list; regmap can be passed
   by irq_drv_data instead
 - Adjust idio_24_set_type_config() for parameter list
 - Add mutex to prevent clobbering the COS_ENABLE register when masking
   IRQ and setting their type configuration
Changes in v2:
 - Simplify PCIe-IDIO-24 register offset defines to remove superfluous
   arithmetic
 - Check for NULL pointer after chip->irq_drv_data allocation
 - Set gpio_regmap drvdata and use gpio_regmap_get_drvdata() to get the
   regmap in idio_24_reg_map_xlate()

The regmap API supports IO port accessors so we can take advantage of
regmap abstractions rather than handling access to the device registers
directly in the driver.

A patch to pass irq_drv_data as a parameter for struct regmap_irq_chip
set_type_config() is included. This is needed by the
idio_24_set_type_config() and ws16c48_set_type_config() callbacks in
order to update the type configuration on their respective devices.

This patchset depends on the "Drop map from handle_mask_sync()
parameters" patchset [0].

[0] https://lore.kernel.org/all/cover.1679323449.git.william.gray@linaro.org/

William Breathitt Gray (3):
  regmap: Pass irq_drv_data as a parameter for set_type_config()
  gpio: pcie-idio-24: Migrate to the regmap API
  gpio: ws16c48: Migrate to the regmap API

 drivers/base/regmap/regmap-irq.c |   6 +-
 drivers/gpio/Kconfig             |   6 +
 drivers/gpio/gpio-pcie-idio-24.c | 677 +++++++++++--------------------
 drivers/gpio/gpio-ws16c48.c      | 552 +++++++++----------------
 include/linux/regmap.h           |   5 +-
 5 files changed, 445 insertions(+), 801 deletions(-)


base-commit: 2093bcd872321a5301470978231b23cc121e3476
prerequisite-patch-id: cd19046150b7cff1be4ac7152198777aa960a3df
prerequisite-patch-id: bd3e3830d9ce4f3876a77483364d7190b7fdffa7
-- 
2.39.2

[PATCH v5 1/3] regmap: Pass irq_drv_data as a parameter for set_type_config()

[William Breathitt Gray]

Allow the struct regmap_irq_chip set_type_config() callback to access
irq_drv_data by passing it as a parameter.

Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
Changes in v5:
 - Wrap lines to 100 characters rather than 80
Changes in v4: none
Changes in v3:
 - Drop map from set_type_config() parameter list; regmap can be passed
   by irq_drv_data instead
Changes in v2: none

 drivers/base/regmap/regmap-irq.c | 6 ++++--
 include/linux/regmap.h           | 5 +++--
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
index ff6b585b9049..6994e59c3e30 100644
--- a/drivers/base/regmap/regmap-irq.c
+++ b/drivers/base/regmap/regmap-irq.c
@@ -329,7 +329,7 @@ static int regmap_irq_set_type(struct irq_data *data, unsigned int type)
 
 	if (d->chip->set_type_config) {
 		ret = d->chip->set_type_config(d->config_buf, type,
-					       irq_data, reg);
+					       irq_data, reg, d->chip->irq_drv_data);
 		if (ret)
 			return ret;
 	}
@@ -653,13 +653,15 @@ EXPORT_SYMBOL_GPL(regmap_irq_get_irq_reg_linear);
  * @type: The requested IRQ type.
  * @irq_data: The IRQ being configured.
  * @idx: Index of the irq's config registers within each array `buf[i]`
+ * @irq_drv_data: Driver specific IRQ data
  *
  * This is a &struct regmap_irq_chip->set_type_config callback suitable for
  * chips with one config register. Register values are updated according to
  * the &struct regmap_irq_type data associated with an IRQ.
  */
 int regmap_irq_set_type_config_simple(unsigned int **buf, unsigned int type,
-				      const struct regmap_irq *irq_data, int idx)
+				      const struct regmap_irq *irq_data, int idx,
+				      void *irq_drv_data)
 {
 	const struct regmap_irq_type *t = &irq_data->type;
 
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 8d9d601da782..9b456e841bec 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -1651,7 +1651,7 @@ struct regmap_irq_chip {
 	int (*set_type_virt)(unsigned int **buf, unsigned int type,
 			     unsigned long hwirq, int reg);
 	int (*set_type_config)(unsigned int **buf, unsigned int type,
-			       const struct regmap_irq *irq_data, int idx);
+			       const struct regmap_irq *irq_data, int idx, void *irq_drv_data);
 	unsigned int (*get_irq_reg)(struct regmap_irq_chip_data *data,
 				    unsigned int base, int index);
 	void *irq_drv_data;
@@ -1660,7 +1660,8 @@ struct regmap_irq_chip {
 unsigned int regmap_irq_get_irq_reg_linear(struct regmap_irq_chip_data *data,
 					   unsigned int base, int index);
 int regmap_irq_set_type_config_simple(unsigned int **buf, unsigned int type,
-				      const struct regmap_irq *irq_data, int idx);
+				      const struct regmap_irq *irq_data, int idx,
+				      void *irq_drv_data);
 
 int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
 			int irq_base, const struct regmap_irq_chip *chip,
-- 
2.39.2

[PATCH v5 2/3] gpio: pcie-idio-24: Migrate to the regmap API

[William Breathitt Gray]

The regmap API supports IO port accessors so we can take advantage of
regmap abstractions rather than handling access to the device registers
directly in the driver.

For the PCIe-IDIO-24 series of devices, the following BARs are
available:

    BAR[0]: memory mapped PEX8311
    BAR[1]: I/O mapped PEX8311
    BAR[2]: I/O mapped card registers

There are 24 FET Output lines, 24 Isolated Input lines, and 8 TTL/CMOS
lines (which may be configured for either output or input). The GPIO
lines are exposed by the following card registers:

    Base +0x0-0x2 (Read/Write): FET Outputs
    Base +0xB (Read/Write): TTL/CMOS
    Base +0x4-0x6 (Read): Isolated Inputs
    Base +0x7 (Read): TTL/CMOS

In order for the device to support interrupts, the PLX PEX8311 internal
PCI wire interrupt and local interrupt input must first be enabled.

The following card registers for Change-Of-State may be used:

    Base +0x8-0xA (Read): COS Status Inputs
    Base +0x8-0xA (Write): COS Clear Inputs
    Base +0xB (Read): COS Status TTL/CMOS
    Base +0xB (Write): COS Clear TTL/CMOS
    Base +0xE (Read/Write): COS Enable

The COS Enable register is used to enable/disable interrupts and
configure the interrupt levels; each bit maps to a group of eight inputs
as described below:

    Bit 0: IRQ EN Rising Edge IN0-7
    Bit 1: IRQ EN Rising Edge IN8-15
    Bit 2: IRQ EN Rising Edge IN16-23
    Bit 3: IRQ EN Rising Edge TTL0-7
    Bit 4: IRQ EN Falling Edge IN0-7
    Bit 5: IRQ EN Falling Edge IN8-15
    Bit 6: IRQ EN Falling Edge IN16-23
    Bit 7: IRQ EN Falling Edge TTL0-7

An interrupt is asserted when a change-of-state matching the interrupt
level configuration respective for a particular group of eight inputs
with enabled COS is detected.

The COS Status registers may be read to determine which inputs have
changed; if interrupts were enabled, an IRQ will be generated for the
set bits in these registers. Writing the value read from the COS Status
register back to the respective COS Clear register will clear just those
interrupts.

Cc: Arnaud de Turckheim <quarium@gmail.com>
Cc: John Hentges <jhentges@accesio.com>
Cc: Jay Dolan <jay.dolan@accesio.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
Changes in v5:
 - Refactor for map parameter removal from handle_mask_sync()
 - Cleanups and line wrappings to 100 characters rather than 80
 - Adjust to change mutex lock to raw_spin_lock_t
 - Remove pex8311_intcsr table configurations as superfluous
 - Adjust to set pex8311_intcsr_regmap_config reg_base to
   PLX_PEX8311_PCI_LCS_INTCSR
Changes in v4:
 - Allocate idio24gpio before using it in idio_24_probe()
Changes in v3:
 - Adjust idio_24_set_type_config() for parameter list
 - Add mutex to prevent clobbering the COS_ENABLE register when masking
   IRQ and setting their type configuration
Changes in v2:
 - Simplify PCIe-IDIO-24 register offset defines to remove superfluous
   arithmetic
 - Check for NULL pointer after chip->irq_drv_data allocation
 - Set gpio_regmap drvdata and use gpio_regmap_get_drvdata() to get the
   regmap in idio_24_reg_map_xlate()

 drivers/gpio/Kconfig             |   3 +
 drivers/gpio/gpio-pcie-idio-24.c | 677 +++++++++++--------------------
 2 files changed, 250 insertions(+), 430 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 68f58b0ba79f..79359f663b3d 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1587,7 +1587,10 @@ config GPIO_PCI_IDIO_16
 
 config GPIO_PCIE_IDIO_24
 	tristate "ACCES PCIe-IDIO-24 GPIO support"
+	select REGMAP_IRQ
+	select REGMAP_MMIO
 	select GPIOLIB_IRQCHIP
+	select GPIO_REGMAP
 	help
 	  Enables GPIO support for the ACCES PCIe-IDIO-24 family (PCIe-IDIO-24,
 	  PCIe-IDI-24, PCIe-IDO-24, PCIe-IDIO-12). An interrupt is generated
diff --git a/drivers/gpio/gpio-pcie-idio-24.c b/drivers/gpio/gpio-pcie-idio-24.c
index 463c0613abb9..9972a3bc3f50 100644
--- a/drivers/gpio/gpio-pcie-idio-24.c
+++ b/drivers/gpio/gpio-pcie-idio-24.c
@@ -6,16 +6,15 @@
  * This driver supports the following ACCES devices: PCIe-IDIO-24,
  * PCIe-IDI-24, PCIe-IDO-24, and PCIe-IDIO-12.
  */
-#include <linux/bitmap.h>
-#include <linux/bitops.h>
+#include <linux/bits.h>
 #include <linux/device.h>
-#include <linux/errno.h>
-#include <linux/gpio/driver.h>
-#include <linux/interrupt.h>
-#include <linux/irqdesc.h>
+#include <linux/err.h>
+#include <linux/gpio/regmap.h>
+#include <linux/irq.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/regmap.h>
 #include <linux/spinlock.h>
 #include <linux/types.h>
 
@@ -59,422 +58,224 @@
 #define PLX_PEX8311_PCI_LCS_INTCSR  0x68
 #define INTCSR_INTERNAL_PCI_WIRE    BIT(8)
 #define INTCSR_LOCAL_INPUT          BIT(11)
+#define IDIO_24_ENABLE_IRQ          (INTCSR_INTERNAL_PCI_WIRE | INTCSR_LOCAL_INPUT)
+
+#define IDIO_24_OUT_BASE 0x0
+#define IDIO_24_TTLCMOS_OUT_REG 0x3
+#define IDIO_24_IN_BASE 0x4
+#define IDIO_24_TTLCMOS_IN_REG 0x7
+#define IDIO_24_COS_STATUS_BASE 0x8
+#define IDIO_24_CONTROL_REG 0xC
+#define IDIO_24_COS_ENABLE 0xE
+#define IDIO_24_SOFT_RESET 0xF
+
+#define CONTROL_REG_OUT_MODE BIT(1)
+
+#define COS_ENABLE_RISING BIT(1)
+#define COS_ENABLE_FALLING BIT(4)
+#define COS_ENABLE_BOTH (COS_ENABLE_RISING | COS_ENABLE_FALLING)
+
+static const struct regmap_config pex8311_intcsr_regmap_config = {
+	.name = "pex8311_intcsr",
+	.reg_bits = 32,
+	.reg_stride = 1,
+	.reg_base = PLX_PEX8311_PCI_LCS_INTCSR,
+	.val_bits = 32,
+	.io_port = true,
+	.max_register = 0x0,
+};
 
-/**
- * struct idio_24_gpio_reg - GPIO device registers structure
- * @out0_7:	Read: FET Outputs 0-7
- *		Write: FET Outputs 0-7
- * @out8_15:	Read: FET Outputs 8-15
- *		Write: FET Outputs 8-15
- * @out16_23:	Read: FET Outputs 16-23
- *		Write: FET Outputs 16-23
- * @ttl_out0_7:	Read: TTL/CMOS Outputs 0-7
- *		Write: TTL/CMOS Outputs 0-7
- * @in0_7:	Read: Isolated Inputs 0-7
- *		Write: Reserved
- * @in8_15:	Read: Isolated Inputs 8-15
- *		Write: Reserved
- * @in16_23:	Read: Isolated Inputs 16-23
- *		Write: Reserved
- * @ttl_in0_7:	Read: TTL/CMOS Inputs 0-7
- *		Write: Reserved
- * @cos0_7:	Read: COS Status Inputs 0-7
- *		Write: COS Clear Inputs 0-7
- * @cos8_15:	Read: COS Status Inputs 8-15
- *		Write: COS Clear Inputs 8-15
- * @cos16_23:	Read: COS Status Inputs 16-23
- *		Write: COS Clear Inputs 16-23
- * @cos_ttl0_7:	Read: COS Status TTL/CMOS 0-7
- *		Write: COS Clear TTL/CMOS 0-7
- * @ctl:	Read: Control Register
- *		Write: Control Register
- * @reserved:	Read: Reserved
- *		Write: Reserved
- * @cos_enable:	Read: COS Enable
- *		Write: COS Enable
- * @soft_reset:	Read: IRQ Output Pin Status
- *		Write: Software Board Reset
- */
-struct idio_24_gpio_reg {
-	u8 out0_7;
-	u8 out8_15;
-	u8 out16_23;
-	u8 ttl_out0_7;
-	u8 in0_7;
-	u8 in8_15;
-	u8 in16_23;
-	u8 ttl_in0_7;
-	u8 cos0_7;
-	u8 cos8_15;
-	u8 cos16_23;
-	u8 cos_ttl0_7;
-	u8 ctl;
-	u8 reserved;
-	u8 cos_enable;
-	u8 soft_reset;
+static const struct regmap_range idio_24_wr_ranges[] = {
+	regmap_reg_range(0x0, 0x3), regmap_reg_range(0x8, 0xC),
+	regmap_reg_range(0xE, 0xF),
+};
+static const struct regmap_range idio_24_rd_ranges[] = {
+	regmap_reg_range(0x0, 0xC), regmap_reg_range(0xE, 0xF),
+};
+static const struct regmap_range idio_24_volatile_ranges[] = {
+	regmap_reg_range(0x4, 0xB), regmap_reg_range(0xF, 0xF),
+};
+static const struct regmap_access_table idio_24_wr_table = {
+	.yes_ranges = idio_24_wr_ranges,
+	.n_yes_ranges = ARRAY_SIZE(idio_24_wr_ranges),
+};
+static const struct regmap_access_table idio_24_rd_table = {
+	.yes_ranges = idio_24_rd_ranges,
+	.n_yes_ranges = ARRAY_SIZE(idio_24_rd_ranges),
+};
+static const struct regmap_access_table idio_24_volatile_table = {
+	.yes_ranges = idio_24_volatile_ranges,
+	.n_yes_ranges = ARRAY_SIZE(idio_24_volatile_ranges),
+};
+
+static const struct regmap_config idio_24_regmap_config = {
+	.reg_bits = 8,
+	.reg_stride = 1,
+	.val_bits = 8,
+	.io_port = true,
+	.max_register = 0xF,
+	.wr_table = &idio_24_wr_table,
+	.rd_table = &idio_24_rd_table,
+	.volatile_table = &idio_24_volatile_table,
+	.cache_type = REGCACHE_FLAT,
+};
+
+#define IDIO_24_NGPIO_PER_REG 8
+#define IDIO_24_REGMAP_IRQ(_id)						\
+	[24 + _id] = {							\
+		.reg_offset = (_id) / IDIO_24_NGPIO_PER_REG,		\
+		.mask = BIT((_id) % IDIO_24_NGPIO_PER_REG),		\
+		.type = { .types_supported = IRQ_TYPE_EDGE_BOTH },	\
+	}
+#define IDIO_24_IIN_IRQ(_id) IDIO_24_REGMAP_IRQ(_id)
+#define IDIO_24_TTL_IRQ(_id) IDIO_24_REGMAP_IRQ(24 + _id)
+
+static const struct regmap_irq idio_24_regmap_irqs[] = {
+	IDIO_24_IIN_IRQ(0), IDIO_24_IIN_IRQ(1), IDIO_24_IIN_IRQ(2), /* IIN 0-2 */
+	IDIO_24_IIN_IRQ(3), IDIO_24_IIN_IRQ(4), IDIO_24_IIN_IRQ(5), /* IIN 3-5 */
+	IDIO_24_IIN_IRQ(6), IDIO_24_IIN_IRQ(7), IDIO_24_IIN_IRQ(8), /* IIN 6-8 */
+	IDIO_24_IIN_IRQ(9), IDIO_24_IIN_IRQ(10), IDIO_24_IIN_IRQ(11), /* IIN 9-11 */
+	IDIO_24_IIN_IRQ(12), IDIO_24_IIN_IRQ(13), IDIO_24_IIN_IRQ(14), /* IIN 12-14 */
+	IDIO_24_IIN_IRQ(15), IDIO_24_IIN_IRQ(16), IDIO_24_IIN_IRQ(17), /* IIN 15-17 */
+	IDIO_24_IIN_IRQ(18), IDIO_24_IIN_IRQ(19), IDIO_24_IIN_IRQ(20), /* IIN 18-20 */
+	IDIO_24_IIN_IRQ(21), IDIO_24_IIN_IRQ(22), IDIO_24_IIN_IRQ(23), /* IIN 21-23 */
+	IDIO_24_TTL_IRQ(0), IDIO_24_TTL_IRQ(1), IDIO_24_TTL_IRQ(2), /* TTL 0-2 */
+	IDIO_24_TTL_IRQ(3), IDIO_24_TTL_IRQ(4), IDIO_24_TTL_IRQ(5), /* TTL 3-5 */
+	IDIO_24_TTL_IRQ(6), IDIO_24_TTL_IRQ(7), /* TTL 6-7 */
 };
 
 /**
  * struct idio_24_gpio - GPIO device private data structure
- * @chip:	instance of the gpio_chip
+ * @map:	regmap for the device
  * @lock:	synchronization lock to prevent I/O race conditions
- * @reg:	I/O address offset for the GPIO device registers
- * @irq_mask:	I/O bits affected by interrupts
+ * @irq_type:	type configuration for IRQs
  */
 struct idio_24_gpio {
-	struct gpio_chip chip;
+	struct regmap *map;
 	raw_spinlock_t lock;
-	__u8 __iomem *plx;
-	struct idio_24_gpio_reg __iomem *reg;
-	unsigned long irq_mask;
+	u8 irq_type;
 };
 
-static int idio_24_gpio_get_direction(struct gpio_chip *chip,
-	unsigned int offset)
-{
-	struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
-	const unsigned long out_mode_mask = BIT(1);
-
-	/* FET Outputs */
-	if (offset < 24)
-		return GPIO_LINE_DIRECTION_OUT;
-
-	/* Isolated Inputs */
-	if (offset < 48)
-		return GPIO_LINE_DIRECTION_IN;
-
-	/* TTL/CMOS I/O */
-	/* OUT MODE = 1 when TTL/CMOS Output Mode is set */
-	if (ioread8(&idio24gpio->reg->ctl) & out_mode_mask)
-		return GPIO_LINE_DIRECTION_OUT;
-
-	return GPIO_LINE_DIRECTION_IN;
-}
-
-static int idio_24_gpio_direction_input(struct gpio_chip *chip,
-	unsigned int offset)
-{
-	struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
-	unsigned long flags;
-	unsigned int ctl_state;
-	const unsigned long out_mode_mask = BIT(1);
-
-	/* TTL/CMOS I/O */
-	if (offset > 47) {
-		raw_spin_lock_irqsave(&idio24gpio->lock, flags);
-
-		/* Clear TTL/CMOS Output Mode */
-		ctl_state = ioread8(&idio24gpio->reg->ctl) & ~out_mode_mask;
-		iowrite8(ctl_state, &idio24gpio->reg->ctl);
-
-		raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
-	}
-
-	return 0;
-}
-
-static int idio_24_gpio_direction_output(struct gpio_chip *chip,
-	unsigned int offset, int value)
-{
-	struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
-	unsigned long flags;
-	unsigned int ctl_state;
-	const unsigned long out_mode_mask = BIT(1);
-
-	/* TTL/CMOS I/O */
-	if (offset > 47) {
-		raw_spin_lock_irqsave(&idio24gpio->lock, flags);
-
-		/* Set TTL/CMOS Output Mode */
-		ctl_state = ioread8(&idio24gpio->reg->ctl) | out_mode_mask;
-		iowrite8(ctl_state, &idio24gpio->reg->ctl);
-
-		raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
-	}
-
-	chip->set(chip, offset, value);
-	return 0;
-}
-
-static int idio_24_gpio_get(struct gpio_chip *chip, unsigned int offset)
+static int idio_24_handle_mask_sync(const int index, const unsigned int mask_buf_def,
+				    const unsigned int mask_buf, void *const irq_drv_data)
 {
-	struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
-	const unsigned long offset_mask = BIT(offset % 8);
-	const unsigned long out_mode_mask = BIT(1);
-
-	/* FET Outputs */
-	if (offset < 8)
-		return !!(ioread8(&idio24gpio->reg->out0_7) & offset_mask);
+	const unsigned int type_mask = COS_ENABLE_BOTH << index;
+	struct idio_24_gpio *const idio24gpio = irq_drv_data;
+	u8 type;
+	int ret;
 
-	if (offset < 16)
-		return !!(ioread8(&idio24gpio->reg->out8_15) & offset_mask);
-
-	if (offset < 24)
-		return !!(ioread8(&idio24gpio->reg->out16_23) & offset_mask);
-
-	/* Isolated Inputs */
-	if (offset < 32)
-		return !!(ioread8(&idio24gpio->reg->in0_7) & offset_mask);
-
-	if (offset < 40)
-		return !!(ioread8(&idio24gpio->reg->in8_15) & offset_mask);
-
-	if (offset < 48)
-		return !!(ioread8(&idio24gpio->reg->in16_23) & offset_mask);
+	raw_spin_lock(&idio24gpio->lock);
 
-	/* TTL/CMOS Outputs */
-	if (ioread8(&idio24gpio->reg->ctl) & out_mode_mask)
-		return !!(ioread8(&idio24gpio->reg->ttl_out0_7) & offset_mask);
+	/* if all are masked, then disable interrupts, else set to type */
+	type = (mask_buf == mask_buf_def) ? ~type_mask : idio24gpio->irq_type;
 
-	/* TTL/CMOS Inputs */
-	return !!(ioread8(&idio24gpio->reg->ttl_in0_7) & offset_mask);
-}
+	ret = regmap_update_bits(idio24gpio->map, IDIO_24_COS_ENABLE, type_mask, type);
 
-static int idio_24_gpio_get_multiple(struct gpio_chip *chip,
-	unsigned long *mask, unsigned long *bits)
-{
-	struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
-	unsigned long offset;
-	unsigned long gpio_mask;
-	void __iomem *ports[] = {
-		&idio24gpio->reg->out0_7, &idio24gpio->reg->out8_15,
-		&idio24gpio->reg->out16_23, &idio24gpio->reg->in0_7,
-		&idio24gpio->reg->in8_15, &idio24gpio->reg->in16_23,
-	};
-	size_t index;
-	unsigned long port_state;
-	const unsigned long out_mode_mask = BIT(1);
-
-	/* clear bits array to a clean slate */
-	bitmap_zero(bits, chip->ngpio);
-
-	for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) {
-		index = offset / 8;
-
-		/* read bits from current gpio port (port 6 is TTL GPIO) */
-		if (index < 6)
-			port_state = ioread8(ports[index]);
-		else if (ioread8(&idio24gpio->reg->ctl) & out_mode_mask)
-			port_state = ioread8(&idio24gpio->reg->ttl_out0_7);
-		else
-			port_state = ioread8(&idio24gpio->reg->ttl_in0_7);
-
-		port_state &= gpio_mask;
-
-		bitmap_set_value8(bits, port_state, offset);
-	}
+	raw_spin_unlock(&idio24gpio->lock);
 
-	return 0;
+	return ret;
 }
 
-static void idio_24_gpio_set(struct gpio_chip *chip, unsigned int offset,
-	int value)
+static int idio_24_set_type_config(unsigned int **const buf, const unsigned int type,
+				   const struct regmap_irq *const irq_data, const int idx,
+				   void *const irq_drv_data)
 {
-	struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
-	const unsigned long out_mode_mask = BIT(1);
-	void __iomem *base;
-	const unsigned int mask = BIT(offset % 8);
-	unsigned long flags;
-	unsigned int out_state;
-
-	/* Isolated Inputs */
-	if (offset > 23 && offset < 48)
-		return;
-
-	/* TTL/CMOS Inputs */
-	if (offset > 47 && !(ioread8(&idio24gpio->reg->ctl) & out_mode_mask))
-		return;
-
-	/* TTL/CMOS Outputs */
-	if (offset > 47)
-		base = &idio24gpio->reg->ttl_out0_7;
-	/* FET Outputs */
-	else if (offset > 15)
-		base = &idio24gpio->reg->out16_23;
-	else if (offset > 7)
-		base = &idio24gpio->reg->out8_15;
-	else
-		base = &idio24gpio->reg->out0_7;
-
-	raw_spin_lock_irqsave(&idio24gpio->lock, flags);
-
-	if (value)
-		out_state = ioread8(base) | mask;
-	else
-		out_state = ioread8(base) & ~mask;
-
-	iowrite8(out_state, base);
-
-	raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
-}
-
-static void idio_24_gpio_set_multiple(struct gpio_chip *chip,
-	unsigned long *mask, unsigned long *bits)
-{
-	struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
-	unsigned long offset;
-	unsigned long gpio_mask;
-	void __iomem *ports[] = {
-		&idio24gpio->reg->out0_7, &idio24gpio->reg->out8_15,
-		&idio24gpio->reg->out16_23
-	};
-	size_t index;
-	unsigned long bitmask;
-	unsigned long flags;
-	unsigned long out_state;
-	const unsigned long out_mode_mask = BIT(1);
-
-	for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) {
-		index = offset / 8;
-
-		bitmask = bitmap_get_value8(bits, offset) & gpio_mask;
-
-		raw_spin_lock_irqsave(&idio24gpio->lock, flags);
-
-		/* read bits from current gpio port (port 6 is TTL GPIO) */
-		if (index < 6) {
-			out_state = ioread8(ports[index]);
-		} else if (ioread8(&idio24gpio->reg->ctl) & out_mode_mask) {
-			out_state = ioread8(&idio24gpio->reg->ttl_out0_7);
-		} else {
-			/* skip TTL GPIO if set for input */
-			raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
-			continue;
-		}
-
-		/* set requested bit states */
-		out_state &= ~gpio_mask;
-		out_state |= bitmask;
-
-		/* write bits for current gpio port (port 6 is TTL GPIO) */
-		if (index < 6)
-			iowrite8(out_state, ports[index]);
-		else
-			iowrite8(out_state, &idio24gpio->reg->ttl_out0_7);
-
-		raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
+	const unsigned int offset = irq_data->reg_offset;
+	const unsigned int rising = COS_ENABLE_RISING << offset;
+	const unsigned int falling = COS_ENABLE_FALLING << offset;
+	const unsigned int mask = COS_ENABLE_BOTH << offset;
+	struct idio_24_gpio *const idio24gpio = irq_drv_data;
+	unsigned int new;
+	unsigned int cos_enable;
+	int ret;
+
+	switch (type) {
+	case IRQ_TYPE_EDGE_RISING:
+		new = rising;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		new = falling;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		new = mask;
+		break;
+	default:
+		return -EINVAL;
 	}
-}
-
-static void idio_24_irq_ack(struct irq_data *data)
-{
-}
 
-static void idio_24_irq_mask(struct irq_data *data)
-{
-	struct gpio_chip *const chip = irq_data_get_irq_chip_data(data);
-	struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
-	unsigned long flags;
-	const unsigned long bit_offset = irqd_to_hwirq(data) - 24;
-	unsigned char new_irq_mask;
-	const unsigned long bank_offset = bit_offset / 8;
-	unsigned char cos_enable_state;
-
-	raw_spin_lock_irqsave(&idio24gpio->lock, flags);
-
-	idio24gpio->irq_mask &= ~BIT(bit_offset);
-	new_irq_mask = idio24gpio->irq_mask >> bank_offset * 8;
+	raw_spin_lock(&idio24gpio->lock);
 
-	if (!new_irq_mask) {
-		cos_enable_state = ioread8(&idio24gpio->reg->cos_enable);
+	/* replace old bitmap with new bitmap */
+	idio24gpio->irq_type = (idio24gpio->irq_type & ~mask) | (new & mask);
 
-		/* Disable Rising Edge detection */
-		cos_enable_state &= ~BIT(bank_offset);
-		/* Disable Falling Edge detection */
-		cos_enable_state &= ~BIT(bank_offset + 4);
+	ret = regmap_read(idio24gpio->map, IDIO_24_COS_ENABLE, &cos_enable);
+	if (ret)
+		goto exit_early;
 
-		iowrite8(cos_enable_state, &idio24gpio->reg->cos_enable);
+	/* if COS is currently enabled then update the edge type */
+	if (cos_enable & mask) {
+		ret = regmap_update_bits(idio24gpio->map, IDIO_24_COS_ENABLE, mask,
+					 idio24gpio->irq_type);
+		goto exit_early;
 	}
 
-	raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
+exit_early:
+	raw_spin_unlock(&idio24gpio->lock);
 
-	gpiochip_disable_irq(chip, irqd_to_hwirq(data));
+	return ret;
 }
 
-static void idio_24_irq_unmask(struct irq_data *data)
+static int idio_24_reg_mask_xlate(struct gpio_regmap *const gpio, const unsigned int base,
+				  const unsigned int offset, unsigned int *const reg,
+				  unsigned int *const mask)
 {
-	struct gpio_chip *const chip = irq_data_get_irq_chip_data(data);
-	struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
-	unsigned long flags;
-	unsigned char prev_irq_mask;
-	const unsigned long bit_offset = irqd_to_hwirq(data) - 24;
-	const unsigned long bank_offset = bit_offset / 8;
-	unsigned char cos_enable_state;
-
-	gpiochip_enable_irq(chip, irqd_to_hwirq(data));
-
-	raw_spin_lock_irqsave(&idio24gpio->lock, flags);
+	const unsigned int out_stride = offset / IDIO_24_NGPIO_PER_REG;
+	const unsigned int in_stride = (offset - 24) / IDIO_24_NGPIO_PER_REG;
+	struct regmap *const map = gpio_regmap_get_drvdata(gpio);
+	int err;
+	unsigned int ctrl_reg;
 
-	prev_irq_mask = idio24gpio->irq_mask >> bank_offset * 8;
-	idio24gpio->irq_mask |= BIT(bit_offset);
+	switch (base) {
+	case IDIO_24_OUT_BASE:
+		*mask = BIT(offset % IDIO_24_NGPIO_PER_REG);
 
-	if (!prev_irq_mask) {
-		cos_enable_state = ioread8(&idio24gpio->reg->cos_enable);
+		/* FET Outputs */
+		if (offset < 24) {
+			*reg = IDIO_24_OUT_BASE + out_stride;
+			return 0;
+		}
 
-		/* Enable Rising Edge detection */
-		cos_enable_state |= BIT(bank_offset);
-		/* Enable Falling Edge detection */
-		cos_enable_state |= BIT(bank_offset + 4);
+		/* Isolated Inputs */
+		if (offset < 48) {
+			*reg = IDIO_24_IN_BASE + in_stride;
+			return 0;
+		}
 
-		iowrite8(cos_enable_state, &idio24gpio->reg->cos_enable);
-	}
+		err = regmap_read(map, IDIO_24_CONTROL_REG, &ctrl_reg);
+		if (err)
+			return err;
 
-	raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
-}
+		/* TTL/CMOS Outputs */
+		if (ctrl_reg & CONTROL_REG_OUT_MODE) {
+			*reg = IDIO_24_TTLCMOS_OUT_REG;
+			return 0;
+		}
 
-static int idio_24_irq_set_type(struct irq_data *data, unsigned int flow_type)
-{
-	/* The only valid irq types are none and both-edges */
-	if (flow_type != IRQ_TYPE_NONE &&
-		(flow_type & IRQ_TYPE_EDGE_BOTH) != IRQ_TYPE_EDGE_BOTH)
+		/* TTL/CMOS Inputs */
+		*reg = IDIO_24_TTLCMOS_IN_REG;
+		return 0;
+	case IDIO_24_CONTROL_REG:
+		/* We can only set direction for TTL/CMOS lines */
+		if (offset < 48)
+			return -EOPNOTSUPP;
+
+		*reg = IDIO_24_CONTROL_REG;
+		*mask = CONTROL_REG_OUT_MODE;
+		return 0;
+	default:
+		/* Should never reach this path */
 		return -EINVAL;
-
-	return 0;
-}
-
-static const struct irq_chip idio_24_irqchip = {
-	.name = "pcie-idio-24",
-	.irq_ack = idio_24_irq_ack,
-	.irq_mask = idio_24_irq_mask,
-	.irq_unmask = idio_24_irq_unmask,
-	.irq_set_type = idio_24_irq_set_type,
-	.flags = IRQCHIP_IMMUTABLE,
-	GPIOCHIP_IRQ_RESOURCE_HELPERS,
-};
-
-static irqreturn_t idio_24_irq_handler(int irq, void *dev_id)
-{
-	struct idio_24_gpio *const idio24gpio = dev_id;
-	unsigned long irq_status;
-	struct gpio_chip *const chip = &idio24gpio->chip;
-	unsigned long irq_mask;
-	int gpio;
-
-	raw_spin_lock(&idio24gpio->lock);
-
-	/* Read Change-Of-State status */
-	irq_status = ioread32(&idio24gpio->reg->cos0_7);
-
-	raw_spin_unlock(&idio24gpio->lock);
-
-	/* Make sure our device generated IRQ */
-	if (!irq_status)
-		return IRQ_NONE;
-
-	/* Handle only unmasked IRQ */
-	irq_mask = idio24gpio->irq_mask & irq_status;
-
-	for_each_set_bit(gpio, &irq_mask, chip->ngpio - 24)
-		generic_handle_domain_irq(chip->irq.domain, gpio + 24);
-
-	raw_spin_lock(&idio24gpio->lock);
-
-	/* Clear Change-Of-State status */
-	iowrite32(irq_status, &idio24gpio->reg->cos0_7);
-
-	raw_spin_unlock(&idio24gpio->lock);
-
-	return IRQ_HANDLED;
+	}
 }
 
 #define IDIO_24_NGPIO 56
@@ -496,11 +297,12 @@ static int idio_24_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	const size_t pci_plx_bar_index = 1;
 	const size_t pci_bar_index = 2;
 	const char *const name = pci_name(pdev);
-	struct gpio_irq_chip *girq;
-
-	idio24gpio = devm_kzalloc(dev, sizeof(*idio24gpio), GFP_KERNEL);
-	if (!idio24gpio)
-		return -ENOMEM;
+	struct gpio_regmap_config gpio_config = {};
+	void __iomem *pex8311_regs;
+	void __iomem *idio_24_regs;
+	struct regmap *intcsr_map;
+	struct regmap_irq_chip *chip;
+	struct regmap_irq_chip_data *chip_data;
 
 	err = pcim_enable_device(pdev);
 	if (err) {
@@ -514,57 +316,72 @@ static int idio_24_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		return err;
 	}
 
-	idio24gpio->plx = pcim_iomap_table(pdev)[pci_plx_bar_index];
-	idio24gpio->reg = pcim_iomap_table(pdev)[pci_bar_index];
-
-	idio24gpio->chip.label = name;
-	idio24gpio->chip.parent = dev;
-	idio24gpio->chip.owner = THIS_MODULE;
-	idio24gpio->chip.base = -1;
-	idio24gpio->chip.ngpio = IDIO_24_NGPIO;
-	idio24gpio->chip.names = idio_24_names;
-	idio24gpio->chip.get_direction = idio_24_gpio_get_direction;
-	idio24gpio->chip.direction_input = idio_24_gpio_direction_input;
-	idio24gpio->chip.direction_output = idio_24_gpio_direction_output;
-	idio24gpio->chip.get = idio_24_gpio_get;
-	idio24gpio->chip.get_multiple = idio_24_gpio_get_multiple;
-	idio24gpio->chip.set = idio_24_gpio_set;
-	idio24gpio->chip.set_multiple = idio_24_gpio_set_multiple;
-
-	girq = &idio24gpio->chip.irq;
-	gpio_irq_chip_set_chip(girq, &idio_24_irqchip);
-	/* This will let us handle the parent IRQ in the driver */
-	girq->parent_handler = NULL;
-	girq->num_parents = 0;
-	girq->parents = NULL;
-	girq->default_type = IRQ_TYPE_NONE;
-	girq->handler = handle_edge_irq;
+	pex8311_regs = pcim_iomap_table(pdev)[pci_plx_bar_index];
+	idio_24_regs = pcim_iomap_table(pdev)[pci_bar_index];
+
+	intcsr_map = devm_regmap_init_mmio(dev, pex8311_regs, &pex8311_intcsr_regmap_config);
+	if (IS_ERR(intcsr_map))
+		return dev_err_probe(dev, PTR_ERR(intcsr_map),
+				     "Unable to initialize PEX8311 register map\n");
+
+	idio24gpio = devm_kzalloc(dev, sizeof(*idio24gpio), GFP_KERNEL);
+	if (!idio24gpio)
+		return -ENOMEM;
+
+	idio24gpio->map = devm_regmap_init_mmio(dev, idio_24_regs, &idio_24_regmap_config);
+	if (IS_ERR(idio24gpio->map))
+		return dev_err_probe(dev, PTR_ERR(idio24gpio->map),
+				     "Unable to initialize register map\n");
 
 	raw_spin_lock_init(&idio24gpio->lock);
 
+	/* Initialize all IRQ type configuration to IRQ_TYPE_EDGE_BOTH */
+	idio24gpio->irq_type = GENMASK(7, 0);
+
+	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->name = name;
+	chip->status_base = IDIO_24_COS_STATUS_BASE;
+	chip->mask_base = IDIO_24_COS_ENABLE;
+	chip->ack_base = IDIO_24_COS_STATUS_BASE;
+	chip->num_regs = 4;
+	chip->irqs = idio_24_regmap_irqs;
+	chip->num_irqs = ARRAY_SIZE(idio_24_regmap_irqs);
+	chip->handle_mask_sync = idio_24_handle_mask_sync;
+	chip->set_type_config = idio_24_set_type_config;
+	chip->irq_drv_data = idio24gpio;
+
 	/* Software board reset */
-	iowrite8(0, &idio24gpio->reg->soft_reset);
+	err = regmap_write(idio24gpio->map, IDIO_24_SOFT_RESET, 0);
+	if (err)
+		return err;
 	/*
 	 * enable PLX PEX8311 internal PCI wire interrupt and local interrupt
 	 * input
 	 */
-	iowrite8((INTCSR_INTERNAL_PCI_WIRE | INTCSR_LOCAL_INPUT) >> 8,
-		 idio24gpio->plx + PLX_PEX8311_PCI_LCS_INTCSR + 1);
-
-	err = devm_gpiochip_add_data(dev, &idio24gpio->chip, idio24gpio);
-	if (err) {
-		dev_err(dev, "GPIO registering failed (%d)\n", err);
+	err = regmap_update_bits(intcsr_map, 0x0, IDIO_24_ENABLE_IRQ, IDIO_24_ENABLE_IRQ);
+	if (err)
 		return err;
-	}
-
-	err = devm_request_irq(dev, pdev->irq, idio_24_irq_handler, IRQF_SHARED,
-		name, idio24gpio);
-	if (err) {
-		dev_err(dev, "IRQ handler registering failed (%d)\n", err);
-		return err;
-	}
 
-	return 0;
+	err = devm_regmap_add_irq_chip(dev, idio24gpio->map, pdev->irq, 0, 0, chip, &chip_data);
+	if (err)
+		return dev_err_probe(dev, err, "IRQ registration failed\n");
+
+	gpio_config.parent = dev;
+	gpio_config.regmap = idio24gpio->map;
+	gpio_config.ngpio = IDIO_24_NGPIO;
+	gpio_config.names = idio_24_names;
+	gpio_config.reg_dat_base = GPIO_REGMAP_ADDR(IDIO_24_OUT_BASE);
+	gpio_config.reg_set_base = GPIO_REGMAP_ADDR(IDIO_24_OUT_BASE);
+	gpio_config.reg_dir_out_base = GPIO_REGMAP_ADDR(IDIO_24_CONTROL_REG);
+	gpio_config.ngpio_per_reg = IDIO_24_NGPIO_PER_REG;
+	gpio_config.irq_domain = regmap_irq_get_domain(chip_data);
+	gpio_config.reg_mask_xlate = idio_24_reg_mask_xlate;
+	gpio_config.drvdata = idio24gpio->map;
+
+	return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &gpio_config));
 }
 
 static const struct pci_device_id idio_24_pci_dev_id[] = {
-- 
2.39.2

[PATCH v5 3/3] gpio: ws16c48: Migrate to the regmap API

[William Breathitt Gray]

The regmap API supports IO port accessors so we can take advantage of
regmap abstractions rather than handling access to the device registers
directly in the driver.

The WinSystems WS16C48 provides the following registers:

    Offset 0x0-0x5: Port 0-5 I/O
    Offset 0x6: Int_Pending
    Offset 0x7: Page/Lock
    Offset 0x8-0xA (Page 1): Pol_0-Pol_2
    Offset 0x8-0xA (Page 2): Enab_0-Enab_2
    Offset 0x8-0xA (Page 3): Int_ID0-Int_ID2

Port 0-5 I/O provides access to 48 lines of digital I/O across six
registers, each bit position corresponding to the respective line.
Writing a 1 to a respective bit position causes that output pin to sink
current, while writing a 0 to the same bit position causes that output
pin to go to a high-impedance state and allows it to be used an input.
Reads on a port report the inverted state (0 = high, 1 = low) of an I/O
pin when used in input mode. Interrupts are supported on Port 0-2.

Int_Pending is a read-only register that reports the combined state of
the INT_ID0 through INT_ID2 registers; an interrupt pending is indicated
when any of the low three bits are set.

The Page/Lock register provides the following bits:

    Bit 0-5: Port 0-5 I/O Lock
    Bit 6-7: Page 0-3 Selection

For Bits 0-5, writing a 1 to a respective bit position locks the output
state of the corresponding I/O port. Writing the page number to Bits 6-7
selects that respective register page for use.

Pol_0-Pol_2 are accessible when Page 1 is selected. Writing a 1 to a
respective bit position selects the rising edge detection interrupts for
that input line, while writing a 0 to the same bit position selects the
falling edge detection interrupts.

Enab_0-Enab_2 are accessible when Page 2 is selected. Writing a 1 to a
respective bit position enables interrupts for that input line, while
writing a 0 to that same bit position clears and disables interrupts for
that input line.

Int_ID0-Int_ID2 are accessible when Page 3 is selected. A respective bit
when read as a 1 indicates that an edge of the polarity set in the
corresponding polarity register was detected for the corresponding input
line. Writing any value to this register clears all pending interrupts
for the register.

Cc: Paul Demetrotion <pdemetrotion@winsystems.com>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
Changes in v5:
 - Refactor for map parameter removal from handle_mask_sync()
 - Cleanups and lines to 100 characters rather than 80
 - Rename PAGE_FIELD_PAGE_* defines to POL_PAGE, ENAB_PAGE, and
   INT_ID_PAGE
 - Adjust to change spinlock_t lock to raw_spin_lock
Changes in v4: none

 drivers/gpio/Kconfig        |   3 +
 drivers/gpio/gpio-ws16c48.c | 552 ++++++++++++------------------------
 2 files changed, 188 insertions(+), 367 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 79359f663b3d..2f6098034753 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -983,7 +983,10 @@ config GPIO_WINBOND
 config GPIO_WS16C48
 	tristate "WinSystems WS16C48 GPIO support"
 	select ISA_BUS_API
+	select REGMAP_IRQ
+	select REGMAP_MMIO
 	select GPIOLIB_IRQCHIP
+	select GPIO_REGMAP
 	help
 	  Enables GPIO support for the WinSystems WS16C48. The base port
 	  addresses for the devices may be configured via the base module
diff --git a/drivers/gpio/gpio-ws16c48.c b/drivers/gpio/gpio-ws16c48.c
index e73885a4dc32..dc11878f397e 100644
--- a/drivers/gpio/gpio-ws16c48.c
+++ b/drivers/gpio/gpio-ws16c48.c
@@ -3,19 +3,18 @@
  * GPIO driver for the WinSystems WS16C48
  * Copyright (C) 2016 William Breathitt Gray
  */
-#include <linux/bitmap.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
 #include <linux/device.h>
-#include <linux/errno.h>
-#include <linux/gpio/driver.h>
-#include <linux/io.h>
-#include <linux/ioport.h>
-#include <linux/interrupt.h>
-#include <linux/irqdesc.h>
+#include <linux/err.h>
+#include <linux/gpio/regmap.h>
+#include <linux/irq.h>
 #include <linux/isa.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/spinlock.h>
+#include <linux/regmap.h>
 #include <linux/types.h>
 
 #define WS16C48_EXTENT 10
@@ -31,371 +30,178 @@ static unsigned int num_irq;
 module_param_hw_array(irq, uint, irq, &num_irq, 0);
 MODULE_PARM_DESC(irq, "WinSystems WS16C48 interrupt line numbers");
 
-/**
- * struct ws16c48_reg - device register structure
- * @port:		Port 0 through 5 I/O
- * @int_pending:	Interrupt Pending
- * @page_lock:		Register page (Bits 7-6) and I/O port lock (Bits 5-0)
- * @pol_enab_int_id:	Interrupt polarity, enable, and ID
- */
-struct ws16c48_reg {
-	u8 port[6];
-	u8 int_pending;
-	u8 page_lock;
-	u8 pol_enab_int_id[3];
+#define WS16C48_DAT_BASE 0x0
+#define WS16C48_PAGE_LOCK 0x7
+#define WS16C48_PAGE_BASE 0x8
+#define WS16C48_POL WS16C48_PAGE_BASE
+#define WS16C48_ENAB WS16C48_PAGE_BASE
+#define WS16C48_INT_ID WS16C48_PAGE_BASE
+
+#define PAGE_LOCK_PAGE_FIELD GENMASK(7, 6)
+#define POL_PAGE u8_encode_bits(1, PAGE_LOCK_PAGE_FIELD)
+#define ENAB_PAGE u8_encode_bits(2, PAGE_LOCK_PAGE_FIELD)
+#define INT_ID_PAGE u8_encode_bits(3, PAGE_LOCK_PAGE_FIELD)
+
+static const struct regmap_range ws16c48_wr_ranges[] = {
+	regmap_reg_range(0x0, 0x5), regmap_reg_range(0x7, 0xA),
+};
+static const struct regmap_range ws16c48_rd_ranges[] = {
+	regmap_reg_range(0x0, 0xA),
+};
+static const struct regmap_range ws16c48_volatile_ranges[] = {
+	regmap_reg_range(0x0, 0x6), regmap_reg_range(0x8, 0xA),
+};
+static const struct regmap_access_table ws16c48_wr_table = {
+	.yes_ranges = ws16c48_wr_ranges,
+	.n_yes_ranges = ARRAY_SIZE(ws16c48_wr_ranges),
+};
+static const struct regmap_access_table ws16c48_rd_table = {
+	.yes_ranges = ws16c48_rd_ranges,
+	.n_yes_ranges = ARRAY_SIZE(ws16c48_rd_ranges),
+};
+static const struct regmap_access_table ws16c48_volatile_table = {
+	.yes_ranges = ws16c48_volatile_ranges,
+	.n_yes_ranges = ARRAY_SIZE(ws16c48_volatile_ranges),
+};
+static const struct regmap_config ws16c48_regmap_config = {
+	.reg_bits = 8,
+	.reg_stride = 1,
+	.val_bits = 8,
+	.io_port = true,
+	.max_register = 0xA,
+	.wr_table = &ws16c48_wr_table,
+	.rd_table = &ws16c48_rd_table,
+	.volatile_table = &ws16c48_volatile_table,
+	.cache_type = REGCACHE_FLAT,
+};
+
+#define WS16C48_NGPIO_PER_REG 8
+#define WS16C48_REGMAP_IRQ(_id)							\
+	[_id] = {								\
+		.reg_offset = (_id) / WS16C48_NGPIO_PER_REG,			\
+		.mask = BIT((_id) % WS16C48_NGPIO_PER_REG),			\
+		.type = {							\
+			.type_reg_offset = (_id) / WS16C48_NGPIO_PER_REG,	\
+			.types_supported = IRQ_TYPE_EDGE_BOTH,			\
+		},								\
+	}
+
+/* Only the first 24 lines (Port 0-2) support interrupts */
+#define WS16C48_NUM_IRQS 24
+static const struct regmap_irq ws16c48_regmap_irqs[WS16C48_NUM_IRQS] = {
+	WS16C48_REGMAP_IRQ(0), WS16C48_REGMAP_IRQ(1), WS16C48_REGMAP_IRQ(2), /* 0-2 */
+	WS16C48_REGMAP_IRQ(3), WS16C48_REGMAP_IRQ(4), WS16C48_REGMAP_IRQ(5), /* 3-5 */
+	WS16C48_REGMAP_IRQ(6), WS16C48_REGMAP_IRQ(7), WS16C48_REGMAP_IRQ(8), /* 6-8 */
+	WS16C48_REGMAP_IRQ(9), WS16C48_REGMAP_IRQ(10), WS16C48_REGMAP_IRQ(11), /* 9-11 */
+	WS16C48_REGMAP_IRQ(12), WS16C48_REGMAP_IRQ(13), WS16C48_REGMAP_IRQ(14), /* 12-14 */
+	WS16C48_REGMAP_IRQ(15), WS16C48_REGMAP_IRQ(16), WS16C48_REGMAP_IRQ(17), /* 15-17 */
+	WS16C48_REGMAP_IRQ(18), WS16C48_REGMAP_IRQ(19), WS16C48_REGMAP_IRQ(20), /* 18-20 */
+	WS16C48_REGMAP_IRQ(21), WS16C48_REGMAP_IRQ(22), WS16C48_REGMAP_IRQ(23), /* 21-23 */
 };
 
 /**
  * struct ws16c48_gpio - GPIO device private data structure
- * @chip:	instance of the gpio_chip
- * @io_state:	bit I/O state (whether bit is set to input or output)
- * @out_state:	output bits state
+ * @map:	regmap for the device
  * @lock:	synchronization lock to prevent I/O race conditions
  * @irq_mask:	I/O bits affected by interrupts
- * @flow_mask:	IRQ flow type mask for the respective I/O bits
- * @reg:	I/O address offset for the device registers
  */
 struct ws16c48_gpio {
-	struct gpio_chip chip;
-	unsigned char io_state[6];
-	unsigned char out_state[6];
+	struct regmap *map;
 	raw_spinlock_t lock;
-	unsigned long irq_mask;
-	unsigned long flow_mask;
-	struct ws16c48_reg __iomem *reg;
+	u8 irq_mask[WS16C48_NUM_IRQS / WS16C48_NGPIO_PER_REG];
 };
 
-static int ws16c48_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
+static int ws16c48_handle_pre_irq(void *const irq_drv_data)
 {
-	struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
-	const unsigned port = offset / 8;
-	const unsigned mask = BIT(offset % 8);
+	struct ws16c48_gpio *const ws16c48gpio = irq_drv_data;
 
-	if (ws16c48gpio->io_state[port] & mask)
-		return GPIO_LINE_DIRECTION_IN;
-
-	return GPIO_LINE_DIRECTION_OUT;
-}
-
-static int ws16c48_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
-{
-	struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
-	const unsigned port = offset / 8;
-	const unsigned mask = BIT(offset % 8);
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
-
-	ws16c48gpio->io_state[port] |= mask;
-	ws16c48gpio->out_state[port] &= ~mask;
-	iowrite8(ws16c48gpio->out_state[port], ws16c48gpio->reg->port + port);
-
-	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
+	/* Lock to prevent Page/Lock register change while we handle IRQ */
+	raw_spin_lock(&ws16c48gpio->lock);
 
 	return 0;
 }
 
-static int ws16c48_gpio_direction_output(struct gpio_chip *chip,
-	unsigned offset, int value)
+static int ws16c48_handle_post_irq(void *const irq_drv_data)
 {
-	struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
-	const unsigned port = offset / 8;
-	const unsigned mask = BIT(offset % 8);
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
+	struct ws16c48_gpio *const ws16c48gpio = irq_drv_data;
 
-	ws16c48gpio->io_state[port] &= ~mask;
-	if (value)
-		ws16c48gpio->out_state[port] |= mask;
-	else
-		ws16c48gpio->out_state[port] &= ~mask;
-	iowrite8(ws16c48gpio->out_state[port], ws16c48gpio->reg->port + port);
-
-	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
+	raw_spin_unlock(&ws16c48gpio->lock);
 
 	return 0;
 }
 
-static int ws16c48_gpio_get(struct gpio_chip *chip, unsigned offset)
-{
-	struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
-	const unsigned port = offset / 8;
-	const unsigned mask = BIT(offset % 8);
-	unsigned long flags;
-	unsigned port_state;
-
-	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
-
-	/* ensure that GPIO is set for input */
-	if (!(ws16c48gpio->io_state[port] & mask)) {
-		raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
-		return -EINVAL;
-	}
-
-	port_state = ioread8(ws16c48gpio->reg->port + port);
-
-	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
-
-	return !!(port_state & mask);
-}
-
-static int ws16c48_gpio_get_multiple(struct gpio_chip *chip,
-	unsigned long *mask, unsigned long *bits)
-{
-	struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
-	unsigned long offset;
-	unsigned long gpio_mask;
-	size_t index;
-	u8 __iomem *port_addr;
-	unsigned long port_state;
-
-	/* clear bits array to a clean slate */
-	bitmap_zero(bits, chip->ngpio);
-
-	for_each_set_clump8(offset, gpio_mask, mask, chip->ngpio) {
-		index = offset / 8;
-		port_addr = ws16c48gpio->reg->port + index;
-		port_state = ioread8(port_addr) & gpio_mask;
-
-		bitmap_set_value8(bits, port_state, offset);
-	}
-
-	return 0;
-}
-
-static void ws16c48_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
-{
-	struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
-	const unsigned port = offset / 8;
-	const unsigned mask = BIT(offset % 8);
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
-
-	/* ensure that GPIO is set for output */
-	if (ws16c48gpio->io_state[port] & mask) {
-		raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
-		return;
-	}
-
-	if (value)
-		ws16c48gpio->out_state[port] |= mask;
-	else
-		ws16c48gpio->out_state[port] &= ~mask;
-	iowrite8(ws16c48gpio->out_state[port], ws16c48gpio->reg->port + port);
-
-	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
-}
-
-static void ws16c48_gpio_set_multiple(struct gpio_chip *chip,
-	unsigned long *mask, unsigned long *bits)
-{
-	struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
-	unsigned long offset;
-	unsigned long gpio_mask;
-	size_t index;
-	u8 __iomem *port_addr;
-	unsigned long bitmask;
-	unsigned long flags;
-
-	for_each_set_clump8(offset, gpio_mask, mask, chip->ngpio) {
-		index = offset / 8;
-		port_addr = ws16c48gpio->reg->port + index;
-
-		/* mask out GPIO configured for input */
-		gpio_mask &= ~ws16c48gpio->io_state[index];
-		bitmask = bitmap_get_value8(bits, offset) & gpio_mask;
-
-		raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
-
-		/* update output state data and set device gpio register */
-		ws16c48gpio->out_state[index] &= ~gpio_mask;
-		ws16c48gpio->out_state[index] |= bitmask;
-		iowrite8(ws16c48gpio->out_state[index], port_addr);
-
-		raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
-	}
-}
-
-static void ws16c48_irq_ack(struct irq_data *data)
+static int ws16c48_handle_mask_sync(const int index, const unsigned int mask_buf_def,
+				    const unsigned int mask_buf, void *const irq_drv_data)
 {
-	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
-	struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
-	const unsigned long offset = irqd_to_hwirq(data);
-	const unsigned port = offset / 8;
-	const unsigned mask = BIT(offset % 8);
+	struct ws16c48_gpio *const ws16c48gpio = irq_drv_data;
 	unsigned long flags;
-	unsigned port_state;
-
-	/* only the first 3 ports support interrupts */
-	if (port > 2)
-		return;
+	int ret = 0;
 
 	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
 
-	port_state = ws16c48gpio->irq_mask >> (8*port);
+	/* exit early if no change since the last mask sync */
+	if (mask_buf == ws16c48gpio->irq_mask[index])
+		goto exit_early;
+	ws16c48gpio->irq_mask[index] = mask_buf;
 
-	/* Select Register Page 2; Unlock all I/O ports */
-	iowrite8(0x80, &ws16c48gpio->reg->page_lock);
+	ret = regmap_write(ws16c48gpio->map, WS16C48_PAGE_LOCK, ENAB_PAGE);
+	if (ret)
+		goto exit_early;
 
-	/* Clear pending interrupt */
-	iowrite8(port_state & ~mask, ws16c48gpio->reg->pol_enab_int_id + port);
-	iowrite8(port_state | mask, ws16c48gpio->reg->pol_enab_int_id + port);
+	/* Update ENAB register (inverted mask) */
+	ret = regmap_write(ws16c48gpio->map, WS16C48_ENAB + index, ~mask_buf);
+	if (ret)
+		goto exit_early;
 
-	/* Select Register Page 3; Unlock all I/O ports */
-	iowrite8(0xC0, &ws16c48gpio->reg->page_lock);
+	ret = regmap_write(ws16c48gpio->map, WS16C48_PAGE_LOCK, INT_ID_PAGE);
+	if (ret)
+		goto exit_early;
 
+exit_early:
 	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
-}
-
-static void ws16c48_irq_mask(struct irq_data *data)
-{
-	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
-	struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
-	const unsigned long offset = irqd_to_hwirq(data);
-	const unsigned long mask = BIT(offset);
-	const unsigned port = offset / 8;
-	unsigned long flags;
-	unsigned long port_state;
-
-	/* only the first 3 ports support interrupts */
-	if (port > 2)
-		return;
-
-	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
 
-	ws16c48gpio->irq_mask &= ~mask;
-	gpiochip_disable_irq(chip, offset);
-	port_state = ws16c48gpio->irq_mask >> (8 * port);
-
-	/* Select Register Page 2; Unlock all I/O ports */
-	iowrite8(0x80, &ws16c48gpio->reg->page_lock);
-
-	/* Disable interrupt */
-	iowrite8(port_state, ws16c48gpio->reg->pol_enab_int_id + port);
-
-	/* Select Register Page 3; Unlock all I/O ports */
-	iowrite8(0xC0, &ws16c48gpio->reg->page_lock);
-
-	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
+	return ret;
 }
 
-static void ws16c48_irq_unmask(struct irq_data *data)
+static int ws16c48_set_type_config(unsigned int **const buf, const unsigned int type,
+				   const struct regmap_irq *const irq_data, const int idx,
+				   void *const irq_drv_data)
 {
-	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
-	struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
-	const unsigned long offset = irqd_to_hwirq(data);
-	const unsigned long mask = BIT(offset);
-	const unsigned port = offset / 8;
+	struct ws16c48_gpio *const ws16c48gpio = irq_drv_data;
+	unsigned int polarity;
 	unsigned long flags;
-	unsigned long port_state;
-
-	/* only the first 3 ports support interrupts */
-	if (port > 2)
-		return;
-
-	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
-
-	gpiochip_enable_irq(chip, offset);
-	ws16c48gpio->irq_mask |= mask;
-	port_state = ws16c48gpio->irq_mask >> (8 * port);
-
-	/* Select Register Page 2; Unlock all I/O ports */
-	iowrite8(0x80, &ws16c48gpio->reg->page_lock);
-
-	/* Enable interrupt */
-	iowrite8(port_state, ws16c48gpio->reg->pol_enab_int_id + port);
-
-	/* Select Register Page 3; Unlock all I/O ports */
-	iowrite8(0xC0, &ws16c48gpio->reg->page_lock);
-
-	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
-}
+	int ret;
 
-static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type)
-{
-	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
-	struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
-	const unsigned long offset = irqd_to_hwirq(data);
-	const unsigned long mask = BIT(offset);
-	const unsigned port = offset / 8;
-	unsigned long flags;
-	unsigned long port_state;
-
-	/* only the first 3 ports support interrupts */
-	if (port > 2)
-		return -EINVAL;
-
-	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
-
-	switch (flow_type) {
-	case IRQ_TYPE_NONE:
-		break;
+	switch (type) {
 	case IRQ_TYPE_EDGE_RISING:
-		ws16c48gpio->flow_mask |= mask;
+		polarity = irq_data->mask;
 		break;
 	case IRQ_TYPE_EDGE_FALLING:
-		ws16c48gpio->flow_mask &= ~mask;
+		polarity = 0;
 		break;
 	default:
-		raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
 		return -EINVAL;
 	}
 
-	port_state = ws16c48gpio->flow_mask >> (8 * port);
+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
 
-	/* Select Register Page 1; Unlock all I/O ports */
-	iowrite8(0x40, &ws16c48gpio->reg->page_lock);
+	ret = regmap_write(ws16c48gpio->map, WS16C48_PAGE_LOCK, POL_PAGE);
+	if (ret)
+		goto exit_early;
 
 	/* Set interrupt polarity */
-	iowrite8(port_state, ws16c48gpio->reg->pol_enab_int_id + port);
+	ret = regmap_update_bits(ws16c48gpio->map, WS16C48_POL + idx, irq_data->mask, polarity);
+	if (ret)
+		goto exit_early;
 
-	/* Select Register Page 3; Unlock all I/O ports */
-	iowrite8(0xC0, &ws16c48gpio->reg->page_lock);
+	ret = regmap_write(ws16c48gpio->map, WS16C48_PAGE_LOCK, INT_ID_PAGE);
+	if (ret)
+		goto exit_early;
 
+exit_early:
 	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
 
-	return 0;
-}
-
-static const struct irq_chip ws16c48_irqchip = {
-	.name = "ws16c48",
-	.irq_ack = ws16c48_irq_ack,
-	.irq_mask = ws16c48_irq_mask,
-	.irq_unmask = ws16c48_irq_unmask,
-	.irq_set_type = ws16c48_irq_set_type,
-	.flags = IRQCHIP_IMMUTABLE,
-	GPIOCHIP_IRQ_RESOURCE_HELPERS,
-};
-
-static irqreturn_t ws16c48_irq_handler(int irq, void *dev_id)
-{
-	struct ws16c48_gpio *const ws16c48gpio = dev_id;
-	struct gpio_chip *const chip = &ws16c48gpio->chip;
-	struct ws16c48_reg __iomem *const reg = ws16c48gpio->reg;
-	unsigned long int_pending;
-	unsigned long port;
-	unsigned long int_id;
-	unsigned long gpio;
-
-	int_pending = ioread8(&reg->int_pending) & 0x7;
-	if (!int_pending)
-		return IRQ_NONE;
-
-	/* loop until all pending interrupts are handled */
-	do {
-		for_each_set_bit(port, &int_pending, 3) {
-			int_id = ioread8(reg->pol_enab_int_id + port);
-			for_each_set_bit(gpio, &int_id, 8)
-				generic_handle_domain_irq(chip->irq.domain,
-							  gpio + 8*port);
-		}
-
-		int_pending = ioread8(&reg->int_pending) & 0x7;
-	} while (int_pending);
-
-	return IRQ_HANDLED;
+	return ret;
 }
 
 #define WS16C48_NGPIO 48
@@ -414,30 +220,37 @@ static const char *ws16c48_names[WS16C48_NGPIO] = {
 	"Port 5 Bit 4", "Port 5 Bit 5", "Port 5 Bit 6", "Port 5 Bit 7"
 };
 
-static int ws16c48_irq_init_hw(struct gpio_chip *gc)
+static int ws16c48_irq_init_hw(struct regmap *const map)
 {
-	struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(gc);
+	int err;
 
-	/* Select Register Page 2; Unlock all I/O ports */
-	iowrite8(0x80, &ws16c48gpio->reg->page_lock);
+	err = regmap_write(map, WS16C48_PAGE_LOCK, ENAB_PAGE);
+	if (err)
+		return err;
 
 	/* Disable interrupts for all lines */
-	iowrite8(0, &ws16c48gpio->reg->pol_enab_int_id[0]);
-	iowrite8(0, &ws16c48gpio->reg->pol_enab_int_id[1]);
-	iowrite8(0, &ws16c48gpio->reg->pol_enab_int_id[2]);
-
-	/* Select Register Page 3; Unlock all I/O ports */
-	iowrite8(0xC0, &ws16c48gpio->reg->page_lock);
+	err = regmap_write(map, WS16C48_ENAB, 0x00);
+	if (err)
+		return err;
+	err = regmap_write(map, WS16C48_ENAB + 1, 0x00);
+	if (err)
+		return err;
+	err = regmap_write(map, WS16C48_ENAB + 2, 0x00);
+	if (err)
+		return err;
 
-	return 0;
+	return regmap_write(map, WS16C48_PAGE_LOCK, INT_ID_PAGE);
 }
 
 static int ws16c48_probe(struct device *dev, unsigned int id)
 {
 	struct ws16c48_gpio *ws16c48gpio;
 	const char *const name = dev_name(dev);
-	struct gpio_irq_chip *girq;
 	int err;
+	struct gpio_regmap_config gpio_config = {};
+	void __iomem *regs;
+	struct regmap_irq_chip *chip;
+	struct regmap_irq_chip_data *chip_data;
 
 	ws16c48gpio = devm_kzalloc(dev, sizeof(*ws16c48gpio), GFP_KERNEL);
 	if (!ws16c48gpio)
@@ -449,50 +262,55 @@ static int ws16c48_probe(struct device *dev, unsigned int id)
 		return -EBUSY;
 	}
 
-	ws16c48gpio->reg = devm_ioport_map(dev, base[id], WS16C48_EXTENT);
-	if (!ws16c48gpio->reg)
+	regs = devm_ioport_map(dev, base[id], WS16C48_EXTENT);
+	if (!regs)
 		return -ENOMEM;
 
-	ws16c48gpio->chip.label = name;
-	ws16c48gpio->chip.parent = dev;
-	ws16c48gpio->chip.owner = THIS_MODULE;
-	ws16c48gpio->chip.base = -1;
-	ws16c48gpio->chip.ngpio = WS16C48_NGPIO;
-	ws16c48gpio->chip.names = ws16c48_names;
-	ws16c48gpio->chip.get_direction = ws16c48_gpio_get_direction;
-	ws16c48gpio->chip.direction_input = ws16c48_gpio_direction_input;
-	ws16c48gpio->chip.direction_output = ws16c48_gpio_direction_output;
-	ws16c48gpio->chip.get = ws16c48_gpio_get;
-	ws16c48gpio->chip.get_multiple = ws16c48_gpio_get_multiple;
-	ws16c48gpio->chip.set = ws16c48_gpio_set;
-	ws16c48gpio->chip.set_multiple = ws16c48_gpio_set_multiple;
-
-	girq = &ws16c48gpio->chip.irq;
-	gpio_irq_chip_set_chip(girq, &ws16c48_irqchip);
-	/* This will let us handle the parent IRQ in the driver */
-	girq->parent_handler = NULL;
-	girq->num_parents = 0;
-	girq->parents = NULL;
-	girq->default_type = IRQ_TYPE_NONE;
-	girq->handler = handle_edge_irq;
-	girq->init_hw = ws16c48_irq_init_hw;
+	ws16c48gpio->map = devm_regmap_init_mmio(dev, regs, &ws16c48_regmap_config);
+	if (IS_ERR(ws16c48gpio->map))
+		return dev_err_probe(dev, PTR_ERR(ws16c48gpio->map),
+				     "Unable to initialize register map\n");
 
-	raw_spin_lock_init(&ws16c48gpio->lock);
+	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
 
-	err = devm_gpiochip_add_data(dev, &ws16c48gpio->chip, ws16c48gpio);
-	if (err) {
-		dev_err(dev, "GPIO registering failed (%d)\n", err);
-		return err;
-	}
+	chip->name = name;
+	chip->status_base = WS16C48_INT_ID;
+	chip->mask_base = WS16C48_ENAB;
+	chip->ack_base = WS16C48_INT_ID;
+	chip->num_regs = 3;
+	chip->irqs = ws16c48_regmap_irqs;
+	chip->num_irqs = ARRAY_SIZE(ws16c48_regmap_irqs);
+	chip->handle_pre_irq = ws16c48_handle_pre_irq;
+	chip->handle_post_irq = ws16c48_handle_post_irq;
+	chip->handle_mask_sync = ws16c48_handle_mask_sync;
+	chip->set_type_config = ws16c48_set_type_config;
+	chip->irq_drv_data = ws16c48gpio;
 
-	err = devm_request_irq(dev, irq[id], ws16c48_irq_handler, IRQF_SHARED,
-		name, ws16c48gpio);
-	if (err) {
-		dev_err(dev, "IRQ handler registering failed (%d)\n", err);
+	raw_spin_lock_init(&ws16c48gpio->lock);
+
+	/* Initialize to prevent spurious interrupts before we're ready */
+	err = ws16c48_irq_init_hw(ws16c48gpio->map);
+	if (err)
 		return err;
-	}
 
-	return 0;
+	err = devm_regmap_add_irq_chip(dev, ws16c48gpio->map, irq[id], 0, 0, chip, &chip_data);
+	if (err)
+		return dev_err_probe(dev, err, "IRQ registration failed\n");
+
+	gpio_config.parent = dev;
+	gpio_config.regmap = ws16c48gpio->map;
+	gpio_config.ngpio = WS16C48_NGPIO;
+	gpio_config.names = ws16c48_names;
+	gpio_config.reg_dat_base = GPIO_REGMAP_ADDR(WS16C48_DAT_BASE);
+	gpio_config.reg_set_base = GPIO_REGMAP_ADDR(WS16C48_DAT_BASE);
+	/* Setting a GPIO to 0 allows it to be used as an input */
+	gpio_config.reg_dir_out_base = GPIO_REGMAP_ADDR(WS16C48_DAT_BASE);
+	gpio_config.ngpio_per_reg = WS16C48_NGPIO_PER_REG;
+	gpio_config.irq_domain = regmap_irq_get_domain(chip_data);
+
+	return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &gpio_config));
 }
 
 static struct isa_driver ws16c48_driver = {
-- 
2.39.2

Re: [PATCH v5 2/3] gpio: pcie-idio-24: Migrate to the regmap API

[Andy Shevchenko]

On Sun, Mar 26, 2023 at 12:25:58PM -0400, William Breathitt Gray wrote:
> The regmap API supports IO port accessors so we can take advantage of
> regmap abstractions rather than handling access to the device registers
> directly in the driver.
> 
> For the PCIe-IDIO-24 series of devices, the following BARs are
> available:
> 
>     BAR[0]: memory mapped PEX8311
>     BAR[1]: I/O mapped PEX8311
>     BAR[2]: I/O mapped card registers
> 
> There are 24 FET Output lines, 24 Isolated Input lines, and 8 TTL/CMOS
> lines (which may be configured for either output or input). The GPIO
> lines are exposed by the following card registers:
> 
>     Base +0x0-0x2 (Read/Write): FET Outputs
>     Base +0xB (Read/Write): TTL/CMOS
>     Base +0x4-0x6 (Read): Isolated Inputs
>     Base +0x7 (Read): TTL/CMOS
> 
> In order for the device to support interrupts, the PLX PEX8311 internal
> PCI wire interrupt and local interrupt input must first be enabled.
> 
> The following card registers for Change-Of-State may be used:
> 
>     Base +0x8-0xA (Read): COS Status Inputs
>     Base +0x8-0xA (Write): COS Clear Inputs
>     Base +0xB (Read): COS Status TTL/CMOS
>     Base +0xB (Write): COS Clear TTL/CMOS
>     Base +0xE (Read/Write): COS Enable
> 
> The COS Enable register is used to enable/disable interrupts and
> configure the interrupt levels; each bit maps to a group of eight inputs
> as described below:
> 
>     Bit 0: IRQ EN Rising Edge IN0-7
>     Bit 1: IRQ EN Rising Edge IN8-15
>     Bit 2: IRQ EN Rising Edge IN16-23
>     Bit 3: IRQ EN Rising Edge TTL0-7
>     Bit 4: IRQ EN Falling Edge IN0-7
>     Bit 5: IRQ EN Falling Edge IN8-15
>     Bit 6: IRQ EN Falling Edge IN16-23
>     Bit 7: IRQ EN Falling Edge TTL0-7
> 
> An interrupt is asserted when a change-of-state matching the interrupt
> level configuration respective for a particular group of eight inputs
> with enabled COS is detected.
> 
> The COS Status registers may be read to determine which inputs have
> changed; if interrupts were enabled, an IRQ will be generated for the
> set bits in these registers. Writing the value read from the COS Status
> register back to the respective COS Clear register will clear just those
> interrupts.

...

> Cc: Arnaud de Turckheim <quarium@gmail.com>
> Cc: John Hentges <jhentges@accesio.com>
> Cc: Jay Dolan <jay.dolan@accesio.com>

You can use --cc parameter to the `git format-patch`.

...

> +static const struct regmap_config pex8311_intcsr_regmap_config = {
> +	.name = "pex8311_intcsr",
> +	.reg_bits = 32,
> +	.reg_stride = 1,
> +	.reg_base = PLX_PEX8311_PCI_LCS_INTCSR,
> +	.val_bits = 32,
> +	.io_port = true,
> +	.max_register = 0x0,
> +};

Do you need regmap lock? If so, what for?

...

> +static const struct regmap_config idio_24_regmap_config = {
> +	.reg_bits = 8,
> +	.reg_stride = 1,
> +	.val_bits = 8,
> +	.io_port = true,
> +	.max_register = 0xF,
> +	.wr_table = &idio_24_wr_table,
> +	.rd_table = &idio_24_rd_table,
> +	.volatile_table = &idio_24_volatile_table,
> +	.cache_type = REGCACHE_FLAT,
> +};

Ditto.

...

> +static int idio_24_set_type_config(unsigned int **const buf, const unsigned int type,
> +				   const struct regmap_irq *const irq_data, const int idx,
> +				   void *const irq_drv_data)
>  {
> +	const unsigned int offset = irq_data->reg_offset;
> +	const unsigned int rising = COS_ENABLE_RISING << offset;
> +	const unsigned int falling = COS_ENABLE_FALLING << offset;
> +	const unsigned int mask = COS_ENABLE_BOTH << offset;
> +	struct idio_24_gpio *const idio24gpio = irq_drv_data;
> +	unsigned int new;
> +	unsigned int cos_enable;
> +	int ret;
> +
> +	switch (type) {
> +	case IRQ_TYPE_EDGE_RISING:
> +		new = rising;
> +		break;
> +	case IRQ_TYPE_EDGE_FALLING:
> +		new = falling;
> +		break;
> +	case IRQ_TYPE_EDGE_BOTH:
> +		new = mask;
> +		break;
> +	default:
> +		return -EINVAL;
>  	}
>  
> +	raw_spin_lock(&idio24gpio->lock);
>  
> +	/* replace old bitmap with new bitmap */
> +	idio24gpio->irq_type = (idio24gpio->irq_type & ~mask) | (new & mask);
>  
> +	ret = regmap_read(idio24gpio->map, IDIO_24_COS_ENABLE, &cos_enable);
> +	if (ret)
> +		goto exit_early;
>  
> +	/* if COS is currently enabled then update the edge type */
> +	if (cos_enable & mask) {
> +		ret = regmap_update_bits(idio24gpio->map, IDIO_24_COS_ENABLE, mask,
> +					 idio24gpio->irq_type);
> +		goto exit_early;
>  	}

> +exit_early:

More descriptive is to call it

exit_unlock:

The rule of thumb is to explain what _will_ happen, if we goto $LABEL.

> +	raw_spin_unlock(&idio24gpio->lock);
>  
> +	return ret;
>  }

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5 3/3] gpio: ws16c48: Migrate to the regmap API

[Andy Shevchenko]

On Sun, Mar 26, 2023 at 12:25:59PM -0400, William Breathitt Gray wrote:
> The regmap API supports IO port accessors so we can take advantage of
> regmap abstractions rather than handling access to the device registers
> directly in the driver.
> 
> The WinSystems WS16C48 provides the following registers:
> 
>     Offset 0x0-0x5: Port 0-5 I/O
>     Offset 0x6: Int_Pending
>     Offset 0x7: Page/Lock
>     Offset 0x8-0xA (Page 1): Pol_0-Pol_2
>     Offset 0x8-0xA (Page 2): Enab_0-Enab_2
>     Offset 0x8-0xA (Page 3): Int_ID0-Int_ID2
> 
> Port 0-5 I/O provides access to 48 lines of digital I/O across six
> registers, each bit position corresponding to the respective line.
> Writing a 1 to a respective bit position causes that output pin to sink
> current, while writing a 0 to the same bit position causes that output
> pin to go to a high-impedance state and allows it to be used an input.
> Reads on a port report the inverted state (0 = high, 1 = low) of an I/O
> pin when used in input mode. Interrupts are supported on Port 0-2.
> 
> Int_Pending is a read-only register that reports the combined state of
> the INT_ID0 through INT_ID2 registers; an interrupt pending is indicated
> when any of the low three bits are set.
> 
> The Page/Lock register provides the following bits:
> 
>     Bit 0-5: Port 0-5 I/O Lock
>     Bit 6-7: Page 0-3 Selection
> 
> For Bits 0-5, writing a 1 to a respective bit position locks the output
> state of the corresponding I/O port. Writing the page number to Bits 6-7
> selects that respective register page for use.
> 
> Pol_0-Pol_2 are accessible when Page 1 is selected. Writing a 1 to a
> respective bit position selects the rising edge detection interrupts for
> that input line, while writing a 0 to the same bit position selects the
> falling edge detection interrupts.
> 
> Enab_0-Enab_2 are accessible when Page 2 is selected. Writing a 1 to a
> respective bit position enables interrupts for that input line, while
> writing a 0 to that same bit position clears and disables interrupts for
> that input line.
> 
> Int_ID0-Int_ID2 are accessible when Page 3 is selected. A respective bit
> when read as a 1 indicates that an edge of the polarity set in the
> corresponding polarity register was detected for the corresponding input
> line. Writing any value to this register clears all pending interrupts
> for the register.

...

> +static const struct regmap_config ws16c48_regmap_config = {
> +	.reg_bits = 8,
> +	.reg_stride = 1,
> +	.val_bits = 8,
> +	.io_port = true,
> +	.max_register = 0xA,
> +	.wr_table = &ws16c48_wr_table,
> +	.rd_table = &ws16c48_rd_table,
> +	.volatile_table = &ws16c48_volatile_table,
> +	.cache_type = REGCACHE_FLAT,
> +};

Do we need regmap lock?

...

>  /**
>   * struct ws16c48_gpio - GPIO device private data structure
> - * @chip:	instance of the gpio_chip
> - * @io_state:	bit I/O state (whether bit is set to input or output)
> - * @out_state:	output bits state
> + * @map:	regmap for the device
>   * @lock:	synchronization lock to prevent I/O race conditions
>   * @irq_mask:	I/O bits affected by interrupts
> - * @flow_mask:	IRQ flow type mask for the respective I/O bits
> - * @reg:	I/O address offset for the device registers
>   */
>  struct ws16c48_gpio {
> -	struct gpio_chip chip;
> -	unsigned char io_state[6];
> -	unsigned char out_state[6];
> +	struct regmap *map;
>  	raw_spinlock_t lock;
> -	unsigned long irq_mask;
> -	unsigned long flow_mask;
> -	struct ws16c48_reg __iomem *reg;
> +	u8 irq_mask[WS16C48_NUM_IRQS / WS16C48_NGPIO_PER_REG];

Looking at this (and also thinking about the previous patch) perhaps this
should be declared as

	DECLARE_BITMAP(...);

and corresponding bit ops to be used?

>  };

...

> +static int ws16c48_handle_pre_irq(void *const irq_drv_data)
>  {
> +	struct ws16c48_gpio *const ws16c48gpio = irq_drv_data;
>  
> +	/* Lock to prevent Page/Lock register change while we handle IRQ */
> +	raw_spin_lock(&ws16c48gpio->lock);
>  
>  	return 0;
>  }

Hmm... Don't we have irq bus lock and unlock callbacks for this?

...

> +static int ws16c48_handle_post_irq(void *const irq_drv_data)
>  {
> +	struct ws16c48_gpio *const ws16c48gpio = irq_drv_data;
>  
> +	raw_spin_unlock(&ws16c48gpio->lock);
>  
>  	return 0;
>  }

Ditto.

Also shouldn't you annotate them for sparse so it won't complain about
unbalanced locks?

...

> +exit_early:

exit_unlock() ?

>  	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);

> +	return ret;

...

> +	err = regmap_write(map, WS16C48_ENAB, 0x00);

				WS16C48_ENAB + 0

(for the sake of symmetry with the below)?

> +	if (err)
> +		return err;
> +	err = regmap_write(map, WS16C48_ENAB + 1, 0x00);
> +	if (err)
> +		return err;
> +	err = regmap_write(map, WS16C48_ENAB + 2, 0x00);
> +	if (err)
> +		return err;

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5 3/3] gpio: ws16c48: Migrate to the regmap API

[William Breathitt Gray]

[-- Attachment #1: Type: text/plain, Size: 6755 bytes --]

On Mon, Mar 27, 2023 at 02:26:37PM +0300, Andy Shevchenko wrote:
> On Sun, Mar 26, 2023 at 12:25:59PM -0400, William Breathitt Gray wrote:
> > The regmap API supports IO port accessors so we can take advantage of
> > regmap abstractions rather than handling access to the device registers
> > directly in the driver.
> > 
> > The WinSystems WS16C48 provides the following registers:
> > 
> >     Offset 0x0-0x5: Port 0-5 I/O
> >     Offset 0x6: Int_Pending
> >     Offset 0x7: Page/Lock
> >     Offset 0x8-0xA (Page 1): Pol_0-Pol_2
> >     Offset 0x8-0xA (Page 2): Enab_0-Enab_2
> >     Offset 0x8-0xA (Page 3): Int_ID0-Int_ID2
> > 
> > Port 0-5 I/O provides access to 48 lines of digital I/O across six
> > registers, each bit position corresponding to the respective line.
> > Writing a 1 to a respective bit position causes that output pin to sink
> > current, while writing a 0 to the same bit position causes that output
> > pin to go to a high-impedance state and allows it to be used an input.
> > Reads on a port report the inverted state (0 = high, 1 = low) of an I/O
> > pin when used in input mode. Interrupts are supported on Port 0-2.
> > 
> > Int_Pending is a read-only register that reports the combined state of
> > the INT_ID0 through INT_ID2 registers; an interrupt pending is indicated
> > when any of the low three bits are set.
> > 
> > The Page/Lock register provides the following bits:
> > 
> >     Bit 0-5: Port 0-5 I/O Lock
> >     Bit 6-7: Page 0-3 Selection
> > 
> > For Bits 0-5, writing a 1 to a respective bit position locks the output
> > state of the corresponding I/O port. Writing the page number to Bits 6-7
> > selects that respective register page for use.
> > 
> > Pol_0-Pol_2 are accessible when Page 1 is selected. Writing a 1 to a
> > respective bit position selects the rising edge detection interrupts for
> > that input line, while writing a 0 to the same bit position selects the
> > falling edge detection interrupts.
> > 
> > Enab_0-Enab_2 are accessible when Page 2 is selected. Writing a 1 to a
> > respective bit position enables interrupts for that input line, while
> > writing a 0 to that same bit position clears and disables interrupts for
> > that input line.
> > 
> > Int_ID0-Int_ID2 are accessible when Page 3 is selected. A respective bit
> > when read as a 1 indicates that an edge of the polarity set in the
> > corresponding polarity register was detected for the corresponding input
> > line. Writing any value to this register clears all pending interrupts
> > for the register.
> 
> ...
> 
> > +static const struct regmap_config ws16c48_regmap_config = {
> > +	.reg_bits = 8,
> > +	.reg_stride = 1,
> > +	.val_bits = 8,
> > +	.io_port = true,
> > +	.max_register = 0xA,
> > +	.wr_table = &ws16c48_wr_table,
> > +	.rd_table = &ws16c48_rd_table,
> > +	.volatile_table = &ws16c48_volatile_table,
> > +	.cache_type = REGCACHE_FLAT,
> > +};
> 
> Do we need regmap lock?

We make regmap calls within an interrupt context in this driver so I
think we need to disable the default regmap mutex locking behavior; I
believe the current raw_spin_lock locking in this driver is enough to
protect access.

> >  /**
> >   * struct ws16c48_gpio - GPIO device private data structure
> > - * @chip:	instance of the gpio_chip
> > - * @io_state:	bit I/O state (whether bit is set to input or output)
> > - * @out_state:	output bits state
> > + * @map:	regmap for the device
> >   * @lock:	synchronization lock to prevent I/O race conditions
> >   * @irq_mask:	I/O bits affected by interrupts
> > - * @flow_mask:	IRQ flow type mask for the respective I/O bits
> > - * @reg:	I/O address offset for the device registers
> >   */
> >  struct ws16c48_gpio {
> > -	struct gpio_chip chip;
> > -	unsigned char io_state[6];
> > -	unsigned char out_state[6];
> > +	struct regmap *map;
> >  	raw_spinlock_t lock;
> > -	unsigned long irq_mask;
> > -	unsigned long flow_mask;
> > -	struct ws16c48_reg __iomem *reg;
> > +	u8 irq_mask[WS16C48_NUM_IRQS / WS16C48_NGPIO_PER_REG];
> 
> Looking at this (and also thinking about the previous patch) perhaps this
> should be declared as
> 
> 	DECLARE_BITMAP(...);
> 
> and corresponding bit ops to be used?

The irq_mask array is just used to store the previous mask_buf state for
comparision against the next time in the ws16c48_handle_mask_sync();
we're just checking if mask_buf has changed so we don't needless write
out to hardware.

I think declaring as BITMAP would obscure the intention of this array,
as well as increase the amount of code in ws16c48_handle_mask_sync()
because mask_buf is not declared as a bitmap and would need to be
converted for comparision against a bitmap irq_mask. So I believe we
should keep irq_mask as an array of u8 for now.

What might be worth discussing is whether the regmap_irq should
internally utilize BITMAP rather than passing around array elements and
indices. The regmap_irq buffer arrays (such as mask_buf) appear to
operate essentially as makeshift bitmaps, so I suspect they could
benefit from the Linux bitmap API.

> > +static int ws16c48_handle_pre_irq(void *const irq_drv_data)
> >  {
> > +	struct ws16c48_gpio *const ws16c48gpio = irq_drv_data;
> >  
> > +	/* Lock to prevent Page/Lock register change while we handle IRQ */
> > +	raw_spin_lock(&ws16c48gpio->lock);
> >  
> >  	return 0;
> >  }
> 
> Hmm... Don't we have irq bus lock and unlock callbacks for this?

The WS16C48 shares the same address space for its interrupt polarity,
IRQ masking, and IRQ status/ACK registers; a page register is utilize in
order to multiplex between the three register pages.

Because the same address space is shared between these different
functions, we use the ws16c48gpio->lock to coordinate access between
them to prevent the registers from being clobbered. For example,
interrupt polarity is set in irq_set_type(), while IRQ masking and
ACKing occurs in irq_bus_sync_unlock(), and IRQ status reading happens
in regmap_irq_thread().

The lock acquired in ws16c48_handle_pre_irq() is for just this last
function of checking the IRQ status. We can't hold it through
irq_bus_lock() because we have to handle IRQ masking and ACKing in
irq_bus_sync_unlock().

> > +static int ws16c48_handle_post_irq(void *const irq_drv_data)
> >  {
> > +	struct ws16c48_gpio *const ws16c48gpio = irq_drv_data;
> >  
> > +	raw_spin_unlock(&ws16c48gpio->lock);
> >  
> >  	return 0;
> >  }
> 
> Ditto.
> 
> Also shouldn't you annotate them for sparse so it won't complain about
> unbalanced locks?

Yes, I'll annotate them with __acquires and __releases respectively.

William Breathitt Gray

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Re: [PATCH v5 1/3] regmap: Pass irq_drv_data as a parameter for set_type_config()

[Mark Brown]

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On Sun, Mar 26, 2023 at 12:25:57PM -0400, William Breathitt Gray wrote:

> Changes in v5:
>  - Wrap lines to 100 characters rather than 80

It's good to keep things under 80 where we can.

>  	int (*set_type_config)(unsigned int **buf, unsigned int type,
> -			       const struct regmap_irq *irq_data, int idx);
> +			       const struct regmap_irq *irq_data, int idx, void *irq_drv_data);
>  	unsigned int (*get_irq_reg)(struct regmap_irq_chip_data *data,
>  				    unsigned int base, int index);
>  	void *irq_drv_data;

There's no benefit from overflowing here and...

> @@ -1660,7 +1660,8 @@ struct regmap_irq_chip {
>  unsigned int regmap_irq_get_irq_reg_linear(struct regmap_irq_chip_data *data,
>  					   unsigned int base, int index);
>  int regmap_irq_set_type_config_simple(unsigned int **buf, unsigned int type,
> -				      const struct regmap_irq *irq_data, int idx);
> +				      const struct regmap_irq *irq_data, int idx,
> +				      void *irq_drv_data);

...it's not even consistent.

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Re: [PATCH v5 3/3] gpio: ws16c48: Migrate to the regmap API

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 957 bytes --]

On Sun, Apr 02, 2023 at 10:39:02AM -0400, William Breathitt Gray wrote:
> On Mon, Mar 27, 2023 at 02:26:37PM +0300, Andy Shevchenko wrote:
> > On Sun, Mar 26, 2023 at 12:25:59PM -0400, William Breathitt Gray wrote:

> > > +static const struct regmap_config ws16c48_regmap_config = {
> > > +	.reg_bits = 8,
> > > +	.reg_stride = 1,
> > > +	.val_bits = 8,
> > > +	.io_port = true,
> > > +	.max_register = 0xA,
> > > +	.wr_table = &ws16c48_wr_table,
> > > +	.rd_table = &ws16c48_rd_table,
> > > +	.volatile_table = &ws16c48_volatile_table,
> > > +	.cache_type = REGCACHE_FLAT,
> > > +};

> > Do we need regmap lock?

> We make regmap calls within an interrupt context in this driver so I
> think we need to disable the default regmap mutex locking behavior; I
> believe the current raw_spin_lock locking in this driver is enough to
> protect access.

The above doesn't configure the regmap locking so you'll have a spinlock
by default (MMIO being a fast bus).

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Re: [PATCH v5 3/3] gpio: ws16c48: Migrate to the regmap API

[William Breathitt Gray]

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On Mon, Apr 03, 2023 at 10:12:44PM +0100, Mark Brown wrote:
> On Sun, Apr 02, 2023 at 10:39:02AM -0400, William Breathitt Gray wrote:
> > On Mon, Mar 27, 2023 at 02:26:37PM +0300, Andy Shevchenko wrote:
> > > On Sun, Mar 26, 2023 at 12:25:59PM -0400, William Breathitt Gray wrote:
> 
> > > > +static const struct regmap_config ws16c48_regmap_config = {
> > > > +	.reg_bits = 8,
> > > > +	.reg_stride = 1,
> > > > +	.val_bits = 8,
> > > > +	.io_port = true,
> > > > +	.max_register = 0xA,
> > > > +	.wr_table = &ws16c48_wr_table,
> > > > +	.rd_table = &ws16c48_rd_table,
> > > > +	.volatile_table = &ws16c48_volatile_table,
> > > > +	.cache_type = REGCACHE_FLAT,
> > > > +};
> 
> > > Do we need regmap lock?
> 
> > We make regmap calls within an interrupt context in this driver so I
> > think we need to disable the default regmap mutex locking behavior; I
> > believe the current raw_spin_lock locking in this driver is enough to
> > protect access.
> 
> The above doesn't configure the regmap locking so you'll have a spinlock
> by default (MMIO being a fast bus).

You're right, it'll be a spinlock in this case and not mutex.
Unfortunately, we'll still need to change that to avoid deadlocks on -rt
kernels [0].

William Breathitt Gray

[0] https://lore.kernel.org/all/1466065537-82027-1-git-send-email-mika.westerberg@linux.intel.com/

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Re: [PATCH v5 3/3] gpio: ws16c48: Migrate to the regmap API

[Mark Brown]

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On Mon, Apr 03, 2023 at 06:20:56PM -0400, William Breathitt Gray wrote:
> On Mon, Apr 03, 2023 at 10:12:44PM +0100, Mark Brown wrote:

> > The above doesn't configure the regmap locking so you'll have a spinlock
> > by default (MMIO being a fast bus).

> You're right, it'll be a spinlock in this case and not mutex.
> Unfortunately, we'll still need to change that to avoid deadlocks on -rt
> kernels [0].

My point is that you haven't actually done that.

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