[PATCH v5 4/8] gpio: 104-idi-48: Migrate to gpio-regmap API

William Breathitt Gray
2022-12-27T14:33:51Z

directly in the driver. Despite the underlying interface being based on
i8255, it is simpler to use the gpio-regmap API directly because the
104-IDI-48 device features only input signals. Therefore, the dependence
on the i8255 GPIO library is removed in this patch.

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>
---
drivers/gpio/Kconfig | 2 +-
drivers/gpio/gpio-104-idi-48.c | 97 +++++++---------------------------
2 files changed, 21 insertions(+), 78 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 30f9e3f48559..84316924574f 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -875,7 +875,7 @@ config GPIO_104_IDI_48
select REGMAP_MMIO
select REGMAP_IRQ
select GPIOLIB_IRQCHIP
- select GPIO_I8255
+ select GPIO_REGMAP
help
Enables GPIO support for the ACCES 104-IDI-48 family (104-IDI-48A,
104-IDI-48AC, 104-IDI-48B, 104-IDI-48BC). The base port addresses for
diff --git a/drivers/gpio/gpio-104-idi-48.c b/drivers/gpio/gpio-104-idi-48.c
index f936e3e0ff12..ca2175b84e24 100644
--- a/drivers/gpio/gpio-104-idi-48.c
+++ b/drivers/gpio/gpio-104-idi-48.c
@@ -9,7 +9,7 @@
#include <linux/bits.h>
#include <linux/device.h>
#include <linux/err.h>
-#include <linux/gpio/driver.h>
+#include <linux/gpio/regmap.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/irq.h>
@@ -20,10 +20,6 @@
#include <linux/regmap.h>
#include <linux/types.h>

-#include "gpio-i8255.h"
-
-MODULE_IMPORT_NS(I8255);
-
#define IDI_48_EXTENT 8
#define MAX_NUM_IDI_48 max_num_isa_dev(IDI_48_EXTENT)

@@ -40,56 +36,17 @@ MODULE_PARM_DESC(irq, "ACCES 104-IDI-48 interrupt line numbers");
#define IDI48_IRQ_STATUS 0x7
#define IDI48_IRQ_ENABLE IDI48_IRQ_STATUS

-/**
- * struct idi_48_reg - device register structure
- * @port0: Port 0 Inputs
- * @unused: Unused
- * @port1: Port 1 Inputs
- * @irq: Read: IRQ Status Register/IRQ Clear
- * Write: IRQ Enable/Disable
- */
-struct idi_48_reg {
- u8 port0[3];
- u8 unused;
- u8 port1[3];
- u8 irq;
-};
-
-/**
- * struct idi_48_gpio - GPIO device private data structure
- * @chip: instance of the gpio_chip
- * @reg: I/O address offset for the device registers
- */
-struct idi_48_gpio {
- struct gpio_chip chip;
- struct idi_48_reg __iomem *reg;
-};
-
-static int idi_48_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
-{
- return GPIO_LINE_DIRECTION_IN;
-}
-
-static int idi_48_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
+static int idi_48_reg_mask_xlate(struct gpio_regmap *gpio, unsigned int base,
+ unsigned int offset, unsigned int *reg,
+ unsigned int *mask)
{
- return 0;
-}
-
-static int idi_48_gpio_get(struct gpio_chip *chip, unsigned int offset)
-{
- struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
- void __iomem *const ppi = idi48gpio->reg;
+ const unsigned int line = offset % 8;
+ const unsigned int stride = offset / 8;
+ const unsigned int port = (stride / 3) * 4;
+ const unsigned int port_stride = stride % 3;

- return i8255_get(ppi, offset);
-}
-
-static int idi_48_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
- unsigned long *bits)
-{
- struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
- void __iomem *const ppi = idi48gpio->reg;
-
- i8255_get_multiple(ppi, mask, bits, chip->ngpio);
+ *reg = base + port + port_stride;
+ *mask = BIT(line);

return 0;
}
@@ -166,18 +123,14 @@ static const char *idi48_names[IDI48_NGPIO] = {

static int idi_48_probe(struct device *dev, unsigned int id)
{
- struct idi_48_gpio *idi48gpio;
const char *const name = dev_name(dev);
+ struct gpio_regmap_config config = {};
void __iomem *regs;
struct regmap *map;
struct regmap_irq_chip *chip;
struct regmap_irq_chip_data *chip_data;
int err;

- idi48gpio = devm_kzalloc(dev, sizeof(*idi48gpio), GFP_KERNEL);
- if (!idi48gpio)
- return -ENOMEM;
-
if (!devm_request_region(dev, base[id], IDI_48_EXTENT, name)) {
dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
base[id], base[id] + IDI_48_EXTENT);
@@ -187,7 +140,6 @@ static int idi_48_probe(struct device *dev, unsigned int id)
regs = devm_ioport_map(dev, base[id], IDI_48_EXTENT);
if (!regs)
return -ENOMEM;
- idi48gpio->reg = regs;

map = devm_regmap_init_mmio(dev, regs, &idi48_regmap_config);
if (IS_ERR(map))
@@ -211,25 +163,16 @@ static int idi_48_probe(struct device *dev, unsigned int id)
if (err)
return dev_err_probe(dev, err, "IRQ registration failed\n");

- idi48gpio->chip.label = name;
- idi48gpio->chip.parent = dev;
- idi48gpio->chip.owner = THIS_MODULE;
- idi48gpio->chip.base = -1;
- idi48gpio->chip.ngpio = IDI48_NGPIO;
- idi48gpio->chip.names = idi48_names;
- idi48gpio->chip.get_direction = idi_48_gpio_get_direction;
- idi48gpio->chip.direction_input = idi_48_gpio_direction_input;
- idi48gpio->chip.get = idi_48_gpio_get;
- idi48gpio->chip.get_multiple = idi_48_gpio_get_multiple;
-
- err = devm_gpiochip_add_data(dev, &idi48gpio->chip, idi48gpio);
- if (err) {
- dev_err(dev, "GPIO registering failed (%d)\n", err);
- return err;
- }
+ config.parent = dev;
+ config.regmap = map;
+ config.ngpio = IDI48_NGPIO;
+ config.names = idi48_names;
+ config.reg_dat_base = GPIO_REGMAP_ADDR(0x0);
+ config.ngpio_per_reg = 8;
+ config.reg_mask_xlate = idi_48_reg_mask_xlate;
+ config.irq_domain = regmap_irq_get_domain(chip_data);

- return gpiochip_irqchip_add_domain(&idi48gpio->chip,
- regmap_irq_get_domain(chip_data));
+ return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &config));
}

static struct isa_driver idi_48_driver = {
--
2.38.1