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path: root/drivers/gpio/gpio-pca9570.c
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Diffstat (limited to 'drivers/gpio/gpio-pca9570.c')
-rw-r--r--drivers/gpio/gpio-pca9570.c185
1 files changed, 185 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-pca9570.c b/drivers/gpio/gpio-pca9570.c
new file mode 100644
index 0000000000..d37ba40493
--- /dev/null
+++ b/drivers/gpio/gpio-pca9570.c
@@ -0,0 +1,185 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for PCA9570 I2C GPO expander
+ *
+ * Copyright (C) 2020 Sungbo Eo <mans0n@gorani.run>
+ *
+ * Based on gpio-tpic2810.c
+ * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
+ * Andrew F. Davis <afd@ti.com>
+ */
+
+#include <linux/gpio/driver.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/property.h>
+
+#define SLG7XL45106_GPO_REG 0xDB
+
+/**
+ * struct pca9570_chip_data - GPIO platformdata
+ * @ngpio: no of gpios
+ * @command: Command to be sent
+ */
+struct pca9570_chip_data {
+ u16 ngpio;
+ u32 command;
+};
+
+/**
+ * struct pca9570 - GPIO driver data
+ * @chip: GPIO controller chip
+ * @chip_data: GPIO controller platform data
+ * @lock: Protects write sequences
+ * @out: Buffer for device register
+ */
+struct pca9570 {
+ struct gpio_chip chip;
+ const struct pca9570_chip_data *chip_data;
+ struct mutex lock;
+ u8 out;
+};
+
+static int pca9570_read(struct pca9570 *gpio, u8 *value)
+{
+ struct i2c_client *client = to_i2c_client(gpio->chip.parent);
+ int ret;
+
+ if (gpio->chip_data->command != 0)
+ ret = i2c_smbus_read_byte_data(client, gpio->chip_data->command);
+ else
+ ret = i2c_smbus_read_byte(client);
+
+ if (ret < 0)
+ return ret;
+
+ *value = ret;
+ return 0;
+}
+
+static int pca9570_write(struct pca9570 *gpio, u8 value)
+{
+ struct i2c_client *client = to_i2c_client(gpio->chip.parent);
+
+ if (gpio->chip_data->command != 0)
+ return i2c_smbus_write_byte_data(client, gpio->chip_data->command, value);
+
+ return i2c_smbus_write_byte(client, value);
+}
+
+static int pca9570_get_direction(struct gpio_chip *chip,
+ unsigned offset)
+{
+ /* This device always output */
+ return GPIO_LINE_DIRECTION_OUT;
+}
+
+static int pca9570_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct pca9570 *gpio = gpiochip_get_data(chip);
+ u8 buffer;
+ int ret;
+
+ ret = pca9570_read(gpio, &buffer);
+ if (ret)
+ return ret;
+
+ return !!(buffer & BIT(offset));
+}
+
+static void pca9570_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ struct pca9570 *gpio = gpiochip_get_data(chip);
+ u8 buffer;
+ int ret;
+
+ mutex_lock(&gpio->lock);
+
+ buffer = gpio->out;
+ if (value)
+ buffer |= BIT(offset);
+ else
+ buffer &= ~BIT(offset);
+
+ ret = pca9570_write(gpio, buffer);
+ if (ret)
+ goto out;
+
+ gpio->out = buffer;
+
+out:
+ mutex_unlock(&gpio->lock);
+}
+
+static int pca9570_probe(struct i2c_client *client)
+{
+ struct pca9570 *gpio;
+
+ gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
+ if (!gpio)
+ return -ENOMEM;
+
+ gpio->chip.label = client->name;
+ gpio->chip.parent = &client->dev;
+ gpio->chip.owner = THIS_MODULE;
+ gpio->chip.get_direction = pca9570_get_direction;
+ gpio->chip.get = pca9570_get;
+ gpio->chip.set = pca9570_set;
+ gpio->chip.base = -1;
+ gpio->chip_data = device_get_match_data(&client->dev);
+ gpio->chip.ngpio = gpio->chip_data->ngpio;
+ gpio->chip.can_sleep = true;
+
+ mutex_init(&gpio->lock);
+
+ /* Read the current output level */
+ pca9570_read(gpio, &gpio->out);
+
+ i2c_set_clientdata(client, gpio);
+
+ return devm_gpiochip_add_data(&client->dev, &gpio->chip, gpio);
+}
+
+static const struct pca9570_chip_data pca9570_gpio = {
+ .ngpio = 4,
+};
+
+static const struct pca9570_chip_data pca9571_gpio = {
+ .ngpio = 8,
+};
+
+static const struct pca9570_chip_data slg7xl45106_gpio = {
+ .ngpio = 8,
+ .command = SLG7XL45106_GPO_REG,
+};
+
+static const struct i2c_device_id pca9570_id_table[] = {
+ { "pca9570", (kernel_ulong_t)&pca9570_gpio},
+ { "pca9571", (kernel_ulong_t)&pca9571_gpio },
+ { "slg7xl45106", (kernel_ulong_t)&slg7xl45106_gpio },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, pca9570_id_table);
+
+static const struct of_device_id pca9570_of_match_table[] = {
+ { .compatible = "dlg,slg7xl45106", .data = &slg7xl45106_gpio},
+ { .compatible = "nxp,pca9570", .data = &pca9570_gpio },
+ { .compatible = "nxp,pca9571", .data = &pca9571_gpio },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, pca9570_of_match_table);
+
+static struct i2c_driver pca9570_driver = {
+ .driver = {
+ .name = "pca9570",
+ .of_match_table = pca9570_of_match_table,
+ },
+ .probe = pca9570_probe,
+ .id_table = pca9570_id_table,
+};
+module_i2c_driver(pca9570_driver);
+
+MODULE_AUTHOR("Sungbo Eo <mans0n@gorani.run>");
+MODULE_DESCRIPTION("GPIO expander driver for PCA9570");
+MODULE_LICENSE("GPL v2");