[PATCH v5 2/4] gpio: 104-idio-16: Migrate to the regmap API

William Breathitt Gray
2023-04-04T14:33:07Z

directly in the driver. Migrate the 104-idio-16 module to the new
idio-16 library interface leveraging the gpio-regmap API.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
Changes in v5:
- Remove regmap_config max_register line as superfluous
- Enable use_raw_spinlock to prevent deadlocks when running -rt kernels

drivers/gpio/Kconfig | 2 +-
drivers/gpio/gpio-104-idio-16.c | 286 +++++++-------------------------
2 files changed, 64 insertions(+), 224 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 415b86cfd1a9..9f7ec4f3fdbf 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -860,7 +860,7 @@ config GPIO_104_IDIO_16
tristate "ACCES 104-IDIO-16 GPIO support"
depends on PC104
select ISA_BUS_API
- select GPIOLIB_IRQCHIP
+ select REGMAP_MMIO
select GPIO_IDIO_16
help
Enables GPIO support for the ACCES 104-IDIO-16 family (104-IDIO-16,
diff --git a/drivers/gpio/gpio-104-idio-16.c b/drivers/gpio/gpio-104-idio-16.c
index 098fbefdbe22..f03ccd0f534c 100644
--- a/drivers/gpio/gpio-104-idio-16.c
+++ b/drivers/gpio/gpio-104-idio-16.c
@@ -6,19 +6,16 @@
* This driver supports the following ACCES devices: 104-IDIO-16,
* 104-IDIO-16E, 104-IDO-16, 104-IDIO-8, 104-IDIO-8E, and 104-IDO-8.
*/
-#include <linux/bitmap.h>
+#include <linux/bits.h>
#include <linux/device.h>
-#include <linux/errno.h>
-#include <linux/gpio/driver.h>
-#include <linux/io.h>
+#include <linux/err.h>
#include <linux/ioport.h>
-#include <linux/interrupt.h>
-#include <linux/irqdesc.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>

#include "gpio-idio-16.h"
@@ -36,187 +33,62 @@ static unsigned int num_irq;
module_param_hw_array(irq, uint, irq, &num_irq, 0);
MODULE_PARM_DESC(irq, "ACCES 104-IDIO-16 interrupt line numbers");

-/**
- * struct idio_16_gpio - GPIO device private data structure
- * @chip: instance of the gpio_chip
- * @lock: synchronization lock to prevent I/O race conditions
- * @irq_mask: I/O bits affected by interrupts
- * @reg: I/O address offset for the device registers
- * @state: ACCES IDIO-16 device state
- */
-struct idio_16_gpio {
- struct gpio_chip chip;
- raw_spinlock_t lock;
- unsigned long irq_mask;
- struct idio_16 __iomem *reg;
- struct idio_16_state state;
+static const struct regmap_range idio_16_wr_ranges[] = {
+ regmap_reg_range(0x0, 0x2), regmap_reg_range(0x4, 0x4),
};
-
-static int idio_16_gpio_get_direction(struct gpio_chip *chip,
- unsigned int offset)
-{
- if (idio_16_get_direction(offset))
- return GPIO_LINE_DIRECTION_IN;
-
- return GPIO_LINE_DIRECTION_OUT;
-}
-
-static int idio_16_gpio_direction_input(struct gpio_chip *chip,
- unsigned int offset)
-{
- return 0;
-}
-
-static int idio_16_gpio_direction_output(struct gpio_chip *chip,
- unsigned int offset, int value)
-{
- chip->set(chip, offset, value);
- return 0;
-}
-
-static int idio_16_gpio_get(struct gpio_chip *chip, unsigned int offset)
-{
- struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
-
- return idio_16_get(idio16gpio->reg, &idio16gpio->state, offset);
-}
-
-static int idio_16_gpio_get_multiple(struct gpio_chip *chip,
- unsigned long *mask, unsigned long *bits)
-{
- struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
-
- idio_16_get_multiple(idio16gpio->reg, &idio16gpio->state, mask, bits);
-
- return 0;
-}
-
-static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset,
- int value)
-{
- struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
-
- idio_16_set(idio16gpio->reg, &idio16gpio->state, offset, value);
-}
-
-static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
- unsigned long *mask, unsigned long *bits)
-{
- struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
-
- idio_16_set_multiple(idio16gpio->reg, &idio16gpio->state, mask, bits);
-}
-
-static void idio_16_irq_ack(struct irq_data *data)
-{
-}
-
-static void idio_16_irq_mask(struct irq_data *data)
-{
- struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
- struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
- const unsigned long offset = irqd_to_hwirq(data);
- unsigned long flags;
-
- idio16gpio->irq_mask &= ~BIT(offset);
- gpiochip_disable_irq(chip, offset);
-
- if (!idio16gpio->irq_mask) {
- raw_spin_lock_irqsave(&idio16gpio->lock, flags);
-
- iowrite8(0, &idio16gpio->reg->irq_ctl);
-
- raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
- }
-}
-
-static void idio_16_irq_unmask(struct irq_data *data)
-{
- struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
- struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
- const unsigned long offset = irqd_to_hwirq(data);
- const unsigned long prev_irq_mask = idio16gpio->irq_mask;
- unsigned long flags;
-
- gpiochip_enable_irq(chip, offset);
- idio16gpio->irq_mask |= BIT(offset);
-
- if (!prev_irq_mask) {
- raw_spin_lock_irqsave(&idio16gpio->lock, flags);
-
- ioread8(&idio16gpio->reg->irq_ctl);
-
- raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
- }
-}
-
-static int idio_16_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)
- return -EINVAL;
-
- return 0;
-}
-
-static const struct irq_chip idio_16_irqchip = {
- .name = "104-idio-16",
- .irq_ack = idio_16_irq_ack,
- .irq_mask = idio_16_irq_mask,
- .irq_unmask = idio_16_irq_unmask,
- .irq_set_type = idio_16_irq_set_type,
- .flags = IRQCHIP_IMMUTABLE,
- GPIOCHIP_IRQ_RESOURCE_HELPERS,
+static const struct regmap_range idio_16_rd_ranges[] = {
+ regmap_reg_range(0x1, 0x2), regmap_reg_range(0x5, 0x5),
};
-
-static irqreturn_t idio_16_irq_handler(int irq, void *dev_id)
-{
- struct idio_16_gpio *const idio16gpio = dev_id;
- struct gpio_chip *const chip = &idio16gpio->chip;
- int gpio;
-
- for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio)
- generic_handle_domain_irq(chip->irq.domain, gpio);
-
- raw_spin_lock(&idio16gpio->lock);
-
- iowrite8(0, &idio16gpio->reg->in0_7);
-
- raw_spin_unlock(&idio16gpio->lock);
-
- return IRQ_HANDLED;
-}
-
-#define IDIO_16_NGPIO 32
-static const char *idio_16_names[IDIO_16_NGPIO] = {
- "OUT0", "OUT1", "OUT2", "OUT3", "OUT4", "OUT5", "OUT6", "OUT7",
- "OUT8", "OUT9", "OUT10", "OUT11", "OUT12", "OUT13", "OUT14", "OUT15",
- "IIN0", "IIN1", "IIN2", "IIN3", "IIN4", "IIN5", "IIN6", "IIN7",
- "IIN8", "IIN9", "IIN10", "IIN11", "IIN12", "IIN13", "IIN14", "IIN15"
+static const struct regmap_range idio_16_precious_ranges[] = {
+ regmap_reg_range(0x2, 0x2),
+};
+static const struct regmap_access_table idio_16_wr_table = {
+ .yes_ranges = idio_16_wr_ranges,
+ .n_yes_ranges = ARRAY_SIZE(idio_16_wr_ranges),
+};
+static const struct regmap_access_table idio_16_rd_table = {
+ .yes_ranges = idio_16_rd_ranges,
+ .n_yes_ranges = ARRAY_SIZE(idio_16_rd_ranges),
+};
+static const struct regmap_access_table idio_16_precious_table = {
+ .yes_ranges = idio_16_precious_ranges,
+ .n_yes_ranges = ARRAY_SIZE(idio_16_precious_ranges),
+};
+static const struct regmap_config idio_16_regmap_config = {
+ .reg_bits = 8,
+ .reg_stride = 1,
+ .val_bits = 8,
+ .io_port = true,
+ .wr_table = &idio_16_wr_table,
+ .rd_table = &idio_16_rd_table,
+ .volatile_table = &idio_16_rd_table,
+ .precious_table = &idio_16_precious_table,
+ .cache_type = REGCACHE_FLAT,
+ .use_raw_spinlock = true,
};

-static int idio_16_irq_init_hw(struct gpio_chip *gc)
-{
- struct idio_16_gpio *const idio16gpio = gpiochip_get_data(gc);
-
- /* Disable IRQ by default */
- iowrite8(0, &idio16gpio->reg->irq_ctl);
- iowrite8(0, &idio16gpio->reg->in0_7);
+/* Only input lines (GPIO 16-31) support interrupts */
+#define IDIO_16_REGMAP_IRQ(_id) \
+ [16 + _id] = { \
+ .mask = BIT(_id), \
+ .type = { .types_supported = IRQ_TYPE_EDGE_BOTH }, \
+ }

- return 0;
-}
+static const struct regmap_irq idio_16_regmap_irqs[] = {
+ IDIO_16_REGMAP_IRQ(0), IDIO_16_REGMAP_IRQ(1), IDIO_16_REGMAP_IRQ(2), /* 0-2 */
+ IDIO_16_REGMAP_IRQ(3), IDIO_16_REGMAP_IRQ(4), IDIO_16_REGMAP_IRQ(5), /* 3-5 */
+ IDIO_16_REGMAP_IRQ(6), IDIO_16_REGMAP_IRQ(7), IDIO_16_REGMAP_IRQ(8), /* 6-8 */
+ IDIO_16_REGMAP_IRQ(9), IDIO_16_REGMAP_IRQ(10), IDIO_16_REGMAP_IRQ(11), /* 9-11 */
+ IDIO_16_REGMAP_IRQ(12), IDIO_16_REGMAP_IRQ(13), IDIO_16_REGMAP_IRQ(14), /* 12-14 */
+ IDIO_16_REGMAP_IRQ(15), /* 15 */
+};

static int idio_16_probe(struct device *dev, unsigned int id)
{
- struct idio_16_gpio *idio16gpio;
const char *const name = dev_name(dev);
- struct gpio_irq_chip *girq;
- int err;
-
- idio16gpio = devm_kzalloc(dev, sizeof(*idio16gpio), GFP_KERNEL);
- if (!idio16gpio)
- return -ENOMEM;
+ struct idio_16_regmap_config config = {};
+ void __iomem *regs;
+ struct regmap *map;

if (!devm_request_region(dev, base[id], IDIO_16_EXTENT, name)) {
dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
@@ -224,54 +96,22 @@ static int idio_16_probe(struct device *dev, unsigned int id)
return -EBUSY;
}

- idio16gpio->reg = devm_ioport_map(dev, base[id], IDIO_16_EXTENT);
- if (!idio16gpio->reg)
+ regs = devm_ioport_map(dev, base[id], IDIO_16_EXTENT);
+ if (!regs)
return -ENOMEM;

- idio16gpio->chip.label = name;
- idio16gpio->chip.parent = dev;
- idio16gpio->chip.owner = THIS_MODULE;
- idio16gpio->chip.base = -1;
- idio16gpio->chip.ngpio = IDIO_16_NGPIO;
- idio16gpio->chip.names = idio_16_names;
- idio16gpio->chip.get_direction = idio_16_gpio_get_direction;
- idio16gpio->chip.direction_input = idio_16_gpio_direction_input;
- idio16gpio->chip.direction_output = idio_16_gpio_direction_output;
- idio16gpio->chip.get = idio_16_gpio_get;
- idio16gpio->chip.get_multiple = idio_16_gpio_get_multiple;
- idio16gpio->chip.set = idio_16_gpio_set;
- idio16gpio->chip.set_multiple = idio_16_gpio_set_multiple;
-
- idio_16_state_init(&idio16gpio->state);
- /* FET off states are represented by bit values of "1" */
- bitmap_fill(idio16gpio->state.out_state, IDIO_16_NOUT);
-
- girq = &idio16gpio->chip.irq;
- gpio_irq_chip_set_chip(girq, &idio_16_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 = idio_16_irq_init_hw;
+ map = devm_regmap_init_mmio(dev, regs, &idio_16_regmap_config);
+ if (IS_ERR(map))
+ return dev_err_probe(dev, PTR_ERR(map), "Unable to initialize register map\n");

- raw_spin_lock_init(&idio16gpio->lock);
-
- err = devm_gpiochip_add_data(dev, &idio16gpio->chip, idio16gpio);
- if (err) {
- dev_err(dev, "GPIO registering failed (%d)\n", err);
- return err;
- }
-
- err = devm_request_irq(dev, irq[id], idio_16_irq_handler, 0, name,
- idio16gpio);
- if (err) {
- dev_err(dev, "IRQ handler registering failed (%d)\n", err);
- return err;
- }
+ config.parent = dev;
+ config.map = map;
+ config.regmap_irqs = idio_16_regmap_irqs;
+ config.num_regmap_irqs = ARRAY_SIZE(idio_16_regmap_irqs);
+ config.irq = irq[id];
+ config.no_status = true;

- return 0;
+ return devm_idio_16_regmap_register(dev, &config);
}

static struct isa_driver idio_16_driver = {
--
2.39.2