drivers/gpio/gpio-bd71828.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 // Copyright (C) 2018 ROHM Semiconductors
0003
0004 #include <linux/gpio/driver.h>
0005 #include <linux/mfd/rohm-bd71828.h>
0006 #include <linux/module.h>
0007 #include <linux/platform_device.h>
0008 #include <linux/regmap.h>
0009
0010 #define GPIO_OUT_REG(off) (BD71828_REG_GPIO_CTRL1 + (off))
0011 #define HALL_GPIO_OFFSET 3
0012
0013 struct bd71828_gpio {
0014     struct regmap *regmap;
0015     struct device *dev;
0016     struct gpio_chip gpio;
0017 };
0018
0019 static void bd71828_gpio_set(struct gpio_chip *chip, unsigned int offset,
0020                  int value)
0021 {
0022     int ret;
0023     struct bd71828_gpio *bdgpio = gpiochip_get_data(chip);
0024     u8 val = (value) ? BD71828_GPIO_OUT_HI : BD71828_GPIO_OUT_LO;
0025
0026     /*
0027      * The HALL input pin can only be used as input. If this is the pin
0028      * we are dealing with - then we are done
0029      */
0030     if (offset == HALL_GPIO_OFFSET)
0031         return;
0032
0033     ret = regmap_update_bits(bdgpio->regmap, GPIO_OUT_REG(offset),
0034                  BD71828_GPIO_OUT_MASK, val);
0035     if (ret)
0036         dev_err(bdgpio->dev, "Could not set gpio to %d\n", value);
0037 }
0038
0039 static int bd71828_gpio_get(struct gpio_chip *chip, unsigned int offset)
0040 {
0041     int ret;
0042     unsigned int val;
0043     struct bd71828_gpio *bdgpio = gpiochip_get_data(chip);
0044
0045     if (offset == HALL_GPIO_OFFSET)
0046         ret = regmap_read(bdgpio->regmap, BD71828_REG_IO_STAT,
0047                   &val);
0048     else
0049         ret = regmap_read(bdgpio->regmap, GPIO_OUT_REG(offset),
0050                   &val);
0051     if (!ret)
0052         ret = (val & BD71828_GPIO_OUT_MASK);
0053
0054     return ret;
0055 }
0056
0057 static int bd71828_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
0058                    unsigned long config)
0059 {
0060     struct bd71828_gpio *bdgpio = gpiochip_get_data(chip);
0061
0062     if (offset == HALL_GPIO_OFFSET)
0063         return -ENOTSUPP;
0064
0065     switch (pinconf_to_config_param(config)) {
0066     case PIN_CONFIG_DRIVE_OPEN_DRAIN:
0067         return regmap_update_bits(bdgpio->regmap,
0068                       GPIO_OUT_REG(offset),
0069                       BD71828_GPIO_DRIVE_MASK,
0070                       BD71828_GPIO_OPEN_DRAIN);
0071     case PIN_CONFIG_DRIVE_PUSH_PULL:
0072         return regmap_update_bits(bdgpio->regmap,
0073                       GPIO_OUT_REG(offset),
0074                       BD71828_GPIO_DRIVE_MASK,
0075                       BD71828_GPIO_PUSH_PULL);
0076     default:
0077         break;
0078     }
0079     return -ENOTSUPP;
0080 }
0081
0082 static int bd71828_get_direction(struct gpio_chip *chip, unsigned int offset)
0083 {
0084     /*
0085      * Pin usage is selected by OTP data. We can't read it runtime. Hence
0086      * we trust that if the pin is not excluded by "gpio-reserved-ranges"
0087      * the OTP configuration is set to OUT. (Other pins but HALL input pin
0088      * on BD71828 can't really be used for general purpose input - input
0089      * states are used for specific cases like regulator control or
0090      * PMIC_ON_REQ.
0091      */
0092     if (offset == HALL_GPIO_OFFSET)
0093         return GPIO_LINE_DIRECTION_IN;
0094
0095     return GPIO_LINE_DIRECTION_OUT;
0096 }
0097
0098 static int bd71828_probe(struct platform_device *pdev)
0099 {
0100     struct device *dev = &pdev->dev;
0101     struct bd71828_gpio *bdgpio;
0102
0103     bdgpio = devm_kzalloc(dev, sizeof(*bdgpio), GFP_KERNEL);
0104     if (!bdgpio)
0105         return -ENOMEM;
0106
0107     bdgpio->dev = dev;
0108     bdgpio->gpio.parent = dev->parent;
0109     bdgpio->gpio.label = "bd71828-gpio";
0110     bdgpio->gpio.owner = THIS_MODULE;
0111     bdgpio->gpio.get_direction = bd71828_get_direction;
0112     bdgpio->gpio.set_config = bd71828_gpio_set_config;
0113     bdgpio->gpio.can_sleep = true;
0114     bdgpio->gpio.get = bd71828_gpio_get;
0115     bdgpio->gpio.set = bd71828_gpio_set;
0116     bdgpio->gpio.base = -1;
0117
0118     /*
0119      * See if we need some implementation to mark some PINs as
0120      * not controllable based on DT info or if core can handle
0121      * "gpio-reserved-ranges" and exclude them from control
0122      */
0123     bdgpio->gpio.ngpio = 4;
0124     bdgpio->regmap = dev_get_regmap(dev->parent, NULL);
0125     if (!bdgpio->regmap)
0126         return -ENODEV;
0127
0128     return devm_gpiochip_add_data(dev, &bdgpio->gpio, bdgpio);
0129 }
0130
0131 static struct platform_driver bd71828_gpio = {
0132     .driver = {
0133         .name = "bd71828-gpio"
0134     },
0135     .probe = bd71828_probe,
0136 };
0137
0138 module_platform_driver(bd71828_gpio);
0139
0140 MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
0141 MODULE_DESCRIPTION("BD71828 voltage regulator driver");
0142 MODULE_LICENSE("GPL");
0143 MODULE_ALIAS("platform:bd71828-gpio");