diff options
Diffstat (limited to 'drivers/gpio/gpio-mockup.c')
| -rw-r--r-- | drivers/gpio/gpio-mockup.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c new file mode 100644 index 000000000000..1ef85b0c2b1f --- /dev/null +++ b/drivers/gpio/gpio-mockup.c @@ -0,0 +1,214 @@ +/* + * GPIO Testing Device Driver + * + * Copyright (C) 2014 Kamlakant Patel <kamlakant.patel@broadcom.com> + * Copyright (C) 2015-2016 Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> + * + * 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. + * + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/gpio/driver.h> +#include <linux/platform_device.h> + +#define GPIO_NAME "gpio-mockup" +#define MAX_GC 10 + +enum direction { + OUT, + IN +}; + +/* + * struct gpio_pin_status - structure describing a GPIO status + * @dir: Configures direction of gpio as "in" or "out", 0=in, 1=out + * @value: Configures status of the gpio as 0(low) or 1(high) + */ +struct gpio_pin_status { + enum direction dir; + bool value; +}; + +struct mockup_gpio_controller { + struct gpio_chip gc; + struct gpio_pin_status *stats; +}; + +static int gpio_mockup_ranges[MAX_GC << 1]; +static int gpio_mockup_params_nr; +module_param_array(gpio_mockup_ranges, int, &gpio_mockup_params_nr, 0400); + +const char pins_name_start = 'A'; + +static int mockup_gpio_get(struct gpio_chip *gc, unsigned int offset) +{ + struct mockup_gpio_controller *cntr = gpiochip_get_data(gc); + + return cntr->stats[offset].value; +} + +static void mockup_gpio_set(struct gpio_chip *gc, unsigned int offset, + int value) +{ + struct mockup_gpio_controller *cntr = gpiochip_get_data(gc); + + cntr->stats[offset].value = !!value; +} + +static int mockup_gpio_dirout(struct gpio_chip *gc, unsigned int offset, + int value) +{ + struct mockup_gpio_controller *cntr = gpiochip_get_data(gc); + + mockup_gpio_set(gc, offset, value); + cntr->stats[offset].dir = OUT; + return 0; +} + +static int mockup_gpio_dirin(struct gpio_chip *gc, unsigned int offset) +{ + struct mockup_gpio_controller *cntr = gpiochip_get_data(gc); + + cntr->stats[offset].dir = IN; + return 0; +} + +static int mockup_gpio_get_direction(struct gpio_chip *gc, unsigned int offset) +{ + struct mockup_gpio_controller *cntr = gpiochip_get_data(gc); + + return cntr->stats[offset].dir; +} + +static int mockup_gpio_add(struct device *dev, + struct mockup_gpio_controller *cntr, + const char *name, int base, int ngpio) +{ + int ret; + + cntr->gc.base = base; + cntr->gc.ngpio = ngpio; + cntr->gc.label = name; + cntr->gc.owner = THIS_MODULE; + cntr->gc.parent = dev; + cntr->gc.get = mockup_gpio_get; + cntr->gc.set = mockup_gpio_set; + cntr->gc.direction_output = mockup_gpio_dirout; + cntr->gc.direction_input = mockup_gpio_dirin; + cntr->gc.get_direction = mockup_gpio_get_direction; + cntr->stats = devm_kzalloc(dev, sizeof(*cntr->stats) * cntr->gc.ngpio, + GFP_KERNEL); + if (!cntr->stats) { + ret = -ENOMEM; + goto err; + } + ret = devm_gpiochip_add_data(dev, &cntr->gc, cntr); + if (ret) + goto err; + + dev_info(dev, "gpio<%d..%d> add successful!", base, base + ngpio); + return 0; +err: + dev_err(dev, "gpio<%d..%d> add failed!", base, base + ngpio); + return ret; +} + +static int mockup_gpio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct mockup_gpio_controller *cntr; + int ret; + int i; + int base; + int ngpio; + char chip_name[sizeof(GPIO_NAME) + 3]; + + if (gpio_mockup_params_nr < 2) + return -EINVAL; + + cntr = devm_kzalloc(dev, sizeof(*cntr) * (gpio_mockup_params_nr >> 1), + GFP_KERNEL); + if (!cntr) + return -ENOMEM; + + platform_set_drvdata(pdev, cntr); + + for (i = 0; i < gpio_mockup_params_nr >> 1; i++) { + base = gpio_mockup_ranges[i * 2]; + if (base == -1) + ngpio = gpio_mockup_ranges[i * 2 + 1]; + else + ngpio = gpio_mockup_ranges[i * 2 + 1] - base; + + if (ngpio >= 0) { + sprintf(chip_name, "%s-%c", GPIO_NAME, + pins_name_start + i); + ret = mockup_gpio_add(dev, &cntr[i], + chip_name, base, ngpio); + } else { + ret = -1; + } + if (ret) { + if (base < 0) + dev_err(dev, "gpio<%d..%d> add failed\n", + base, ngpio); + else + dev_err(dev, "gpio<%d..%d> add failed\n", + base, base + ngpio); + + return ret; + } + } + + return 0; +} + +static struct platform_driver mockup_gpio_driver = { + .driver = { + .name = GPIO_NAME, + }, + .probe = mockup_gpio_probe, +}; + +static struct platform_device *pdev; +static int __init mock_device_init(void) +{ + int err; + + pdev = platform_device_alloc(GPIO_NAME, -1); + if (!pdev) + return -ENOMEM; + + err = platform_device_add(pdev); + if (err) { + platform_device_put(pdev); + return err; + } + + err = platform_driver_register(&mockup_gpio_driver); + if (err) { + platform_device_unregister(pdev); + return err; + } + + return 0; +} + +static void __exit mock_device_exit(void) +{ + platform_driver_unregister(&mockup_gpio_driver); + platform_device_unregister(pdev); +} + +module_init(mock_device_init); +module_exit(mock_device_exit); + +MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>"); +MODULE_AUTHOR("Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>"); +MODULE_DESCRIPTION("GPIO Testing driver"); +MODULE_LICENSE("GPL v2"); |