Gpio I/O expander.
Signed-off-by: Okan Sahin <okan.sahin@xxxxxxxxxx>
---
drivers/gpio/Kconfig | 10 ++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-ds4520.c | 198 +++++++++++++++++++++++++++++++++++++
3 files changed, 209 insertions(+)
create mode 100644 drivers/gpio/gpio-ds4520.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 13be729710f2..20aa28e208d5 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1000,6 +1000,16 @@ config GPIO_ADNP
enough to represent all pins, but the driver will assume a
register layout for 64 pins (8 registers).
+config GPIO_DS4520
+ tristate "DS4520 I2C GPIO expander"
+ select REGMAP_I2C
+ help
+ GPIO driver for Maxim MAX7300 I2C-based GPIO expander.
+ Say yes here to enable the GPIO driver for the ADI DS4520 chip.
+
+ To compile this driver as a module, choose M here: the module will
+ be called gpio-ds4520.
+
config GPIO_GW_PLD
tristate "Gateworks PLD GPIO Expander"
depends on OF_GPIO
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index c048ba003367..6f8656d5d617 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_GPIO_DA9052) += gpio-da9052.o
obj-$(CONFIG_GPIO_DA9055) += gpio-da9055.o
obj-$(CONFIG_GPIO_DAVINCI) += gpio-davinci.o
obj-$(CONFIG_GPIO_DLN2) += gpio-dln2.o
+obj-$(CONFIG_GPIO_DS4520) += gpio-ds4520.o
obj-$(CONFIG_GPIO_DWAPB) += gpio-dwapb.o
obj-$(CONFIG_GPIO_EIC_SPRD) += gpio-eic-sprd.o
obj-$(CONFIG_GPIO_EM) += gpio-em.o
diff --git a/drivers/gpio/gpio-ds4520.c b/drivers/gpio/gpio-ds4520.c
new file mode 100644
index 000000000000..8f878e7824b8
--- /dev/null
+++ b/drivers/gpio/gpio-ds4520.c
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2023 Analog Devices, Inc.
+ * Driver for the DS4520 I/O Expander
+ */
+
+#include <linux/bits.h>
+#include <linux/bitfield.h>
+#include <linux/gpio/driver.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+
+#define NUMBER_OF_GPIO 9
+
+#define PULLUP0 0xF0
+#define IO_CONTROL0 0xF2
+#define IO_STATUS0 0xF8
+
+#define REG_SIZE 8
+
+struct ds4520_gpio_priv {
+ struct regmap *regmap;
+ struct gpio_chip gpio_chip;
+};
+
+static int ds4520_gpio_get_direction(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct ds4520_gpio_priv *priv = gpiochip_get_data(chip);
+ u32 val_io_control = 0, val_pullup = 0;
+ u8 reg_offset = (offset / REG_SIZE);
+ int ret;
+
+ ret = regmap_set_bits(priv->regmap, 0xF4, 0x01);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(priv->regmap, IO_CONTROL0 + reg_offset,
+ &val_io_control);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(priv->regmap, PULLUP0 + reg_offset, &val_pullup);
+ if (ret)
+ return ret;
+
+ if ((val_io_control & (1 << (offset % 8)))
+ == (val_pullup & (1 << (offset % 8))))
+ return GPIO_LINE_DIRECTION_OUT;
+ else
+ return GPIO_LINE_DIRECTION_IN;
+}
+
+static int ds4520_gpio_direction_input(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct ds4520_gpio_priv *priv = gpiochip_get_data(chip);
+ u8 reg_offset = (offset / REG_SIZE);
+ u8 mask = BIT(offset % 8);
+ int ret;
+
+ ret = regmap_clear_bits(priv->regmap, IO_CONTROL0 + reg_offset, mask);
+ if (ret)
+ return ret;
+
+ ret = regmap_set_bits(priv->regmap, PULLUP0 + reg_offset, mask);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int ds4520_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+ struct ds4520_gpio_priv *priv = gpiochip_get_data(chip);
+ u8 reg_offset = (offset / REG_SIZE);
+ u8 mask = BIT(offset % 8);
+ u32 val = 0;
+ int ret;
+
+ ret = regmap_read(priv->regmap, IO_STATUS0 + reg_offset, &val);
+ if (ret)
+ return ret;
+
+ return !!(val & mask);
+}
+
+static void ds4520_gpio_set(struct gpio_chip *chip, unsigned int offset,
+ int value)
+{
+ struct ds4520_gpio_priv *priv = gpiochip_get_data(chip);
+ u8 reg_offset = (offset / REG_SIZE);
+ u8 mask = BIT(offset % 8);
+
+ regmap_update_bits(priv->regmap, PULLUP0 + reg_offset, mask,
+ value ? mask : 0);
+ regmap_update_bits(priv->regmap, IO_CONTROL0 + reg_offset, mask,
+ value ? mask : 0);
+}
+
+static int ds4520_gpio_direction_output(struct gpio_chip *chip,
+ unsigned int offset, int value)
+{
+ struct ds4520_gpio_priv *priv = gpiochip_get_data(chip);
+ u8 reg_offset = (offset / REG_SIZE);
+ u8 mask = BIT(offset % 8);
+ int ret;
+
+ ret = regmap_clear_bits(priv->regmap, IO_CONTROL0 + reg_offset, mask);
+ if (ret)
+ return ret;
+
+ ds4520_gpio_set(chip, offset, value);
+
+ return 0;
+}
+
+static const struct regmap_config ds4520_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+
+static const struct gpio_chip ds4520_chip = {
+ .label = "ds4520-gpio",
+ .owner = THIS_MODULE,
+ .get_direction = ds4520_gpio_get_direction,
+ .direction_input = ds4520_gpio_direction_input,
+ .direction_output = ds4520_gpio_direction_output,
+ .get = ds4520_gpio_get,
+ .set = ds4520_gpio_set,
+ .base = -1,
+ .can_sleep = true,
+};
+
+static int ds4520_gpio_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct ds4520_gpio_priv *priv;
+ u32 ngpio;
+ int ret;
+
+ ngpio = NUMBER_OF_GPIO;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->gpio_chip = ds4520_chip;
+ priv->gpio_chip.label = "ds4520-gpio";
+ priv->gpio_chip.ngpio = ngpio;
+ priv->gpio_chip.parent = dev;
+
+ priv->regmap = devm_regmap_init_i2c(client, &ds4520_regmap_config);
+ if (IS_ERR(priv->regmap)) {
+ ret = PTR_ERR(priv->regmap);
+ dev_err_probe(dev, ret,
+ "Failed to allocate register map\n");
+ return ret;
+ }
+
+ ret = devm_gpiochip_add_data(dev, &priv->gpio_chip, priv);
+ if (ret) {
+ dev_err_probe(dev, ret, "Unable to register gpiochip\n");
+ return ret;
+ }
+
+ i2c_set_clientdata(client, priv);
+
+ return 0;
+}
+
+static const struct of_device_id ds4520_gpio_of_match_table[] = {
+ {
+ .compatible = "adi,ds4520-gpio"
+ },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ds4520_gpio_of_match_table);
+
+static const struct i2c_device_id ds4520_gpio_id_table[] = {
+ { "ds4520-gpio" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, ds4520_gpio_id_table);
+
+static struct i2c_driver ds4520_gpio_driver = {
+ .driver = {
+ .name = "ds4520-gpio",
+ .of_match_table = ds4520_gpio_of_match_table,
+ },
+ .probe_new = ds4520_gpio_probe,
+ .id_table = ds4520_gpio_id_table,
+};
+module_i2c_driver(ds4520_gpio_driver);
+
+MODULE_DESCRIPTION("DS4520 I/O Expander");
+MODULE_AUTHOR("Okan Sahin <okan.sahin@xxxxxxxxxx>");
+MODULE_LICENSE("GPL");
--
2.30.2
