From 16d44b6085c1d90884b264deb938a34ab85a9c6d Mon Sep 17 00:00:00 2001 From: Sungbo Eo Date: Thu, 9 Jul 2020 22:48:29 +0900 Subject: [PATCH] gpio: pca9570: add GPO driver for PCA9570 NXP PCA9570 is a 4-bit I2C GPO expander without interrupt functionality. Its ports are controlled only by a data byte without register address. Signed-off-by: Sungbo Eo Reviewed-by: Andy Shevchenko Datasheet: https://www.nxp.com/docs/en/data-sheet/PCA9570.pdf Link: https://lore.kernel.org/r/20200709134829.216393-1-mans0n@gorani.run Signed-off-by: Linus Walleij --- drivers/gpio/Kconfig | 8 +++ drivers/gpio/Makefile | 1 + drivers/gpio/gpio-pca9570.c | 146 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 155 insertions(+) create mode 100644 drivers/gpio/gpio-pca9570.c diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 05e0801..8030fd9 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -962,6 +962,14 @@ 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_PCA9570 + tristate "PCA9570 4-Bit I2C GPO expander" + help + Say yes here to enable the GPO driver for the NXP PCA9570 chip. + + To compile this driver as a module, choose M here: the module will + be called gpio-pca9570. + config GPIO_PCF857X tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders" select GPIOLIB_IRQCHIP diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index ef666cf..4f9abff4 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -111,6 +111,7 @@ obj-$(CONFIG_GPIO_OCTEON) += gpio-octeon.o obj-$(CONFIG_GPIO_OMAP) += gpio-omap.o obj-$(CONFIG_GPIO_PALMAS) += gpio-palmas.o obj-$(CONFIG_GPIO_PCA953X) += gpio-pca953x.o +obj-$(CONFIG_GPIO_PCA9570) += gpio-pca9570.o obj-$(CONFIG_GPIO_PCF857X) += gpio-pcf857x.o obj-$(CONFIG_GPIO_PCH) += gpio-pch.o obj-$(CONFIG_GPIO_PCIE_IDIO_24) += gpio-pcie-idio-24.o diff --git a/drivers/gpio/gpio-pca9570.c b/drivers/gpio/gpio-pca9570.c new file mode 100644 index 0000000..cb2b2f7 --- /dev/null +++ b/drivers/gpio/gpio-pca9570.c @@ -0,0 +1,146 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for PCA9570 I2C GPO expander + * + * Copyright (C) 2020 Sungbo Eo + * + * Based on gpio-tpic2810.c + * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/ + * Andrew F. Davis + */ + +#include +#include +#include +#include +#include + +/** + * struct pca9570 - GPIO driver data + * @chip: GPIO controller chip + * @lock: Protects write sequences + * @out: Buffer for device register + */ +struct pca9570 { + struct gpio_chip chip; + 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; + + 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); + + 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.ngpio = (uintptr_t)device_get_match_data(&client->dev); + 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 i2c_device_id pca9570_id_table[] = { + { "pca9570", 4 }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(i2c, pca9570_id_table); + +static const struct of_device_id pca9570_of_match_table[] = { + { .compatible = "nxp,pca9570", .data = (void *)4 }, + { /* 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_new = pca9570_probe, + .id_table = pca9570_id_table, +}; +module_i2c_driver(pca9570_driver); + +MODULE_AUTHOR("Sungbo Eo "); +MODULE_DESCRIPTION("GPIO expander driver for PCA9570"); +MODULE_LICENSE("GPL v2"); -- 2.7.4