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1// SPDX-License-Identifier: GPL-2.02/*3 * Support to GPOs on ROHM BD718154 * Copyright 2021 ROHM Semiconductors.5 * Author: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>6 *7 * Copyright 2014 Embest Technology Co. Ltd. Inc.8 * Author: yanglsh@embest-tech.com9 */10 11#include <linux/gpio/driver.h>12#include <linux/init.h>13#include <linux/irq.h>14#include <linux/module.h>15#include <linux/of.h>16#include <linux/platform_device.h>17/* For the BD71815 register definitions */18#include <linux/mfd/rohm-bd71815.h>19 20struct bd71815_gpio {21 /* chip.parent points the MFD which provides DT node and regmap */22 struct gpio_chip chip;23 /* dev points to the platform device for devm and prints */24 struct device *dev;25 struct regmap *regmap;26};27 28static int bd71815gpo_get(struct gpio_chip *chip, unsigned int offset)29{30 struct bd71815_gpio *bd71815 = gpiochip_get_data(chip);31 int ret, val;32 33 ret = regmap_read(bd71815->regmap, BD71815_REG_GPO, &val);34 if (ret)35 return ret;36 37 return (val >> offset) & 1;38}39 40static void bd71815gpo_set(struct gpio_chip *chip, unsigned int offset,41 int value)42{43 struct bd71815_gpio *bd71815 = gpiochip_get_data(chip);44 int ret, bit;45 46 bit = BIT(offset);47 48 if (value)49 ret = regmap_set_bits(bd71815->regmap, BD71815_REG_GPO, bit);50 else51 ret = regmap_clear_bits(bd71815->regmap, BD71815_REG_GPO, bit);52 53 if (ret)54 dev_warn(bd71815->dev, "failed to toggle GPO\n");55}56 57static int bd71815_gpio_set_config(struct gpio_chip *chip, unsigned int offset,58 unsigned long config)59{60 struct bd71815_gpio *bdgpio = gpiochip_get_data(chip);61 62 switch (pinconf_to_config_param(config)) {63 case PIN_CONFIG_DRIVE_OPEN_DRAIN:64 return regmap_update_bits(bdgpio->regmap,65 BD71815_REG_GPO,66 BD71815_GPIO_DRIVE_MASK << offset,67 BD71815_GPIO_OPEN_DRAIN << offset);68 case PIN_CONFIG_DRIVE_PUSH_PULL:69 return regmap_update_bits(bdgpio->regmap,70 BD71815_REG_GPO,71 BD71815_GPIO_DRIVE_MASK << offset,72 BD71815_GPIO_CMOS << offset);73 default:74 break;75 }76 return -ENOTSUPP;77}78 79/* BD71815 GPIO is actually GPO */80static int bd71815gpo_direction_get(struct gpio_chip *gc, unsigned int offset)81{82 return GPIO_LINE_DIRECTION_OUT;83}84 85/* Template for GPIO chip */86static const struct gpio_chip bd71815gpo_chip = {87 .label = "bd71815",88 .owner = THIS_MODULE,89 .get = bd71815gpo_get,90 .get_direction = bd71815gpo_direction_get,91 .set = bd71815gpo_set,92 .set_config = bd71815_gpio_set_config,93 .can_sleep = true,94};95 96#define BD71815_TWO_GPIOS GENMASK(1, 0)97#define BD71815_ONE_GPIO BIT(0)98 99/*100 * Sigh. The BD71815 and BD71817 were originally designed to support two GPO101 * pins. At some point it was noticed the second GPO pin which is the E5 pin102 * located at the center of IC is hard to use on PCB (due to the location). It103 * was decided to not promote this second GPO and the pin is marked as GND in104 * the datasheet. The functionality is still there though! I guess driving a GPO105 * connected to the ground is a bad idea. Thus we do not support it by default.106 * OTOH - the original driver written by colleagues at Embest did support107 * controlling this second GPO. It is thus possible this is used in some of the108 * products.109 *110 * This driver does not by default support configuring this second GPO111 * but allows using it by providing the DT property112 * "rohm,enable-hidden-gpo".113 */114static int bd71815_init_valid_mask(struct gpio_chip *gc,115 unsigned long *valid_mask,116 unsigned int ngpios)117{118 if (ngpios != 2)119 return 0;120 121 if (gc->parent && device_property_present(gc->parent,122 "rohm,enable-hidden-gpo"))123 *valid_mask = BD71815_TWO_GPIOS;124 else125 *valid_mask = BD71815_ONE_GPIO;126 127 return 0;128}129 130static int gpo_bd71815_probe(struct platform_device *pdev)131{132 struct bd71815_gpio *g;133 struct device *parent, *dev;134 135 /*136 * Bind devm lifetime to this platform device => use dev for devm.137 * also the prints should originate from this device.138 */139 dev = &pdev->dev;140 /* The device-tree and regmap come from MFD => use parent for that */141 parent = dev->parent;142 143 g = devm_kzalloc(dev, sizeof(*g), GFP_KERNEL);144 if (!g)145 return -ENOMEM;146 147 g->chip = bd71815gpo_chip;148 149 /*150 * FIXME: As writing of this the sysfs interface for GPIO control does151 * not respect the valid_mask. Do not trust it but rather set the ngpios152 * to 1 if "rohm,enable-hidden-gpo" is not given.153 *154 * This check can be removed later if the sysfs export is fixed and155 * if the fix is backported.156 *157 * For now it is safest to just set the ngpios though.158 */159 if (device_property_present(parent, "rohm,enable-hidden-gpo"))160 g->chip.ngpio = 2;161 else162 g->chip.ngpio = 1;163 164 g->chip.init_valid_mask = bd71815_init_valid_mask;165 g->chip.base = -1;166 g->chip.parent = parent;167 g->regmap = dev_get_regmap(parent, NULL);168 g->dev = dev;169 170 return devm_gpiochip_add_data(dev, &g->chip, g);171}172 173static struct platform_driver gpo_bd71815_driver = {174 .driver = {175 .name = "bd71815-gpo",176 },177 .probe = gpo_bd71815_probe,178};179module_platform_driver(gpo_bd71815_driver);180 181MODULE_ALIAS("platform:bd71815-gpo");182MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");183MODULE_AUTHOR("Peter Yang <yanglsh@embest-tech.com>");184MODULE_DESCRIPTION("GPO interface for BD71815");185MODULE_LICENSE("GPL");186