The PCA9621 is an I2C 8-bit output open-drain expander.
Signed-off-by: Laurent Pinchart <[email protected]>
---
.../devicetree/bindings/gpio/nxp,pca9621.txt | 19 +++
drivers/gpio/Kconfig | 6 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-pca9621.c | 163 +++++++++++++++++++++
4 files changed, 189 insertions(+)
create mode 100644 Documentation/devicetree/bindings/gpio/nxp,pca9621.txt
create mode 100644 drivers/gpio/gpio-pca9621.c
diff --git a/Documentation/devicetree/bindings/gpio/nxp,pca9621.txt
b/Documentation/devicetree/bindings/gpio/nxp,pca9621.txt
new file mode 100644
index 000000000000..f863aa23150b
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/nxp,pca9621.txt
@@ -0,0 +1,19 @@
+* NXP PCA9621 I2C GPIO multiplexer
+
+Required properties:
+
+ - compatible: Should be "nxp,pca9621".
+ - gpio-controller: Marks the device as a gpio controller.
+ - #gpio-cells: Should be 2. The first cell is the GPIO number and the second
+ cell specifies GPIO flags, as defined in <dt-bindings/gpio/gpio.h>. Only the
+ GPIO_ACTIVE_HIGH and GPIO_ACTIVE_LOW flags are supported.
+
+
+Example:
+
+ gpio@20 {
+ compatible = "nxp,pca9621";
+ reg = <0x20>;
+ gpio-controller;
+ #gpio-cells = <2>;
+ };
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 8f1fe739c985..f0e19fc0add8 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -644,6 +644,12 @@ config GPIO_PCA953X_IRQ
Say yes here to enable the pca953x to be used as an interrupt
controller. It requires the driver to be built in the kernel.
+config GPIO_PCA9621
+ tristate "PCA9621 I2C output port"
+ depends on I2C
+ help
+ Say yes here to provide access to the PCA9621 I2C output expander.
+
config GPIO_PCF857X
tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders"
depends on I2C
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index f82cd678ce08..36f5cb5eade6 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_GPIO_MXS) += gpio-mxs.o
obj-$(CONFIG_GPIO_OCTEON) += gpio-octeon.o
obj-$(CONFIG_GPIO_OMAP) += gpio-omap.o
obj-$(CONFIG_GPIO_PCA953X) += gpio-pca953x.o
+obj-$(CONFIG_GPIO_PCA9621) += gpio-pca9621.o
obj-$(CONFIG_GPIO_PCF857X) += gpio-pcf857x.o
obj-$(CONFIG_GPIO_PCH) += gpio-pch.o
obj-$(CONFIG_GPIO_PL061) += gpio-pl061.o
diff --git a/drivers/gpio/gpio-pca9621.c b/drivers/gpio/gpio-pca9621.c
new file mode 100644
index 000000000000..c26bb5126dea
--- /dev/null
+++ b/drivers/gpio/gpio-pca9621.c
@@ -0,0 +1,163 @@
+/*
+ * Driver for pca9621 I2C GPIO expanders
+ *
+ * Copyright (C) 2015 Laurent Pinchart
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+struct pca9621 {
+ struct gpio_chip chip;
+ struct i2c_client *client;
+ struct mutex lock; /* protect 'out' */
+ unsigned int out;
+};
+
+static inline struct pca9621 *to_pca9621(struct gpio_chip *chip)
+{
+ return container_of(chip, struct pca9621, chip);
+}
+
+static int pca9621_input(struct gpio_chip *chip, unsigned offset)
+{
+ struct pca9621 *gpio = to_pca9621(chip);
+ int ret;
+
+ mutex_lock(&gpio->lock);
+
+ gpio->out &= ~(1 << offset);
+ ret = i2c_smbus_write_byte(gpio->client, gpio->out);
+
+ mutex_unlock(&gpio->lock);
+
+ return ret;
+}
+
+static int pca9621_output(struct gpio_chip *chip, unsigned offset, int value)
+{
+ struct pca9621 *gpio = to_pca9621(chip);
+ int ret;
+
+ /* The output is open-drain and can't be driven high. */
+ if (value)
+ return -EINVAL;
+
+ mutex_lock(&gpio->lock);
+
+ gpio->out |= 1 << offset;
+ ret = i2c_smbus_write_byte(gpio->client, gpio->out);
+
+ mutex_unlock(&gpio->lock);
+
+ return ret;
+}
+
+static int pca9621_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct pca9621 *gpio = to_pca9621(chip);
+
+ return !(gpio->out & (1 << offset));
+}
+
+static void pca9621_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ pca9621_output(chip, offset, value);
+}
+
+static int pca9621_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct pca9621 *gpio;
+ int ret;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE))
+ return -EIO;
+
+ gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
+ if (!gpio)
+ return -ENOMEM;
+
+ mutex_init(&gpio->lock);
+
+ gpio->chip.base = -1;
+ gpio->chip.can_sleep = true;
+ gpio->chip.dev = &client->dev;
+ gpio->chip.owner = THIS_MODULE;
+ gpio->chip.get = pca9621_get;
+ gpio->chip.set = pca9621_set;
+ gpio->chip.direction_input = pca9621_input;
+ gpio->chip.direction_output = pca9621_output;
+ gpio->chip.ngpio = 8;
+ gpio->chip.label = client->name;
+
+ gpio->client = client;
+ i2c_set_clientdata(client, gpio);
+
+ /* Read the current output state. */
+ ret = i2c_smbus_read_byte(gpio->client);
+ if (ret < 0)
+ return ret;
+
+ gpio->out = ret;
+
+ ret = gpiochip_add(&gpio->chip);
+ if (ret < 0)
+ return ret;
+
+ dev_info(&client->dev, "probed\n");
+
+ return 0;
+}
+
+static int pca9621_remove(struct i2c_client *client)
+{
+ struct pca9621 *gpio = i2c_get_clientdata(client);
+
+ gpiochip_remove(&gpio->chip);
+
+ return 0;
+}
+
+static const struct i2c_device_id pca9621_id[] = {
+ { "pca9621" },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, pca9621_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id pca9621_of_table[] = {
+ { .compatible = "nxp,pca9621" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, pca9621_of_table);
+#endif
+
+static struct i2c_driver pca9621_driver = {
+ .driver = {
+ .name = "pca9621",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(pca9621_of_table),
+ },
+ .probe = pca9621_probe,
+ .remove = pca9621_remove,
+ .id_table = pca9621_id,
+};
+module_i2c_driver(pca9621_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Laurent Pinchart");
--
2.4.9
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