| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * SAMA5D2 PIOBU GPIO controller |
| * |
| * Copyright (C) 2018 Microchip Technology Inc. and its subsidiaries |
| * |
| * Author: Andrei Stefanescu <andrei.stefanescu@microchip.com> |
| * |
| */ |
| #include <linux/bits.h> |
| #include <linux/gpio/driver.h> |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/mfd/syscon.h> |
| #include <linux/module.h> |
| #include <linux/of.h> |
| #include <linux/platform_device.h> |
| #include <linux/regmap.h> |
| |
| #define PIOBU_NUM 8 |
| #define PIOBU_REG_SIZE 4 |
| |
| /* |
| * backup mode protection register for tamper detection |
| * normal mode protection register for tamper detection |
| * wakeup signal generation |
| */ |
| #define PIOBU_BMPR 0x7C |
| #define PIOBU_NMPR 0x80 |
| #define PIOBU_WKPR 0x90 |
| |
| #define PIOBU_BASE 0x18 /* PIOBU offset from SECUMOD base register address. */ |
| |
| #define PIOBU_DET_OFFSET 16 |
| |
| /* In the datasheet this bit is called OUTPUT */ |
| #define PIOBU_DIRECTION BIT(8) |
| #define PIOBU_OUT BIT(8) |
| #define PIOBU_IN 0 |
| |
| #define PIOBU_SOD BIT(9) |
| #define PIOBU_PDS BIT(10) |
| |
| #define PIOBU_HIGH BIT(9) |
| #define PIOBU_LOW 0 |
| |
| struct sama5d2_piobu { |
| struct gpio_chip chip; |
| struct regmap *regmap; |
| }; |
| |
| /** |
| * sama5d2_piobu_setup_pin() - prepares a pin for set_direction call |
| * |
| * Do not consider pin for tamper detection (normal and backup modes) |
| * Do not consider pin as tamper wakeup interrupt source |
| */ |
| static int sama5d2_piobu_setup_pin(struct gpio_chip *chip, unsigned int pin) |
| { |
| int ret; |
| struct sama5d2_piobu *piobu = container_of(chip, struct sama5d2_piobu, |
| chip); |
| unsigned int mask = BIT(PIOBU_DET_OFFSET + pin); |
| |
| ret = regmap_update_bits(piobu->regmap, PIOBU_BMPR, mask, 0); |
| if (ret) |
| return ret; |
| |
| ret = regmap_update_bits(piobu->regmap, PIOBU_NMPR, mask, 0); |
| if (ret) |
| return ret; |
| |
| return regmap_update_bits(piobu->regmap, PIOBU_WKPR, mask, 0); |
| } |
| |
| /** |
| * sama5d2_piobu_write_value() - writes value & mask at the pin's PIOBU register |
| */ |
| static int sama5d2_piobu_write_value(struct gpio_chip *chip, unsigned int pin, |
| unsigned int mask, unsigned int value) |
| { |
| int reg; |
| struct sama5d2_piobu *piobu = container_of(chip, struct sama5d2_piobu, |
| chip); |
| |
| reg = PIOBU_BASE + pin * PIOBU_REG_SIZE; |
| |
| return regmap_update_bits(piobu->regmap, reg, mask, value); |
| } |
| |
| /** |
| * sama5d2_piobu_read_value() - read the value with masking from the pin's PIOBU |
| * register |
| */ |
| static int sama5d2_piobu_read_value(struct gpio_chip *chip, unsigned int pin, |
| unsigned int mask) |
| { |
| struct sama5d2_piobu *piobu = container_of(chip, struct sama5d2_piobu, |
| chip); |
| unsigned int val, reg; |
| int ret; |
| |
| reg = PIOBU_BASE + pin * PIOBU_REG_SIZE; |
| ret = regmap_read(piobu->regmap, reg, &val); |
| if (ret < 0) |
| return ret; |
| |
| return val & mask; |
| } |
| |
| /** |
| * sama5d2_piobu_get_direction() - gpiochip get_direction |
| */ |
| static int sama5d2_piobu_get_direction(struct gpio_chip *chip, |
| unsigned int pin) |
| { |
| int ret = sama5d2_piobu_read_value(chip, pin, PIOBU_DIRECTION); |
| |
| if (ret < 0) |
| return ret; |
| |
| return (ret == PIOBU_IN) ? 1 : 0; |
| } |
| |
| /** |
| * sama5d2_piobu_direction_input() - gpiochip direction_input |
| */ |
| static int sama5d2_piobu_direction_input(struct gpio_chip *chip, |
| unsigned int pin) |
| { |
| return sama5d2_piobu_write_value(chip, pin, PIOBU_DIRECTION, PIOBU_IN); |
| } |
| |
| /** |
| * sama5d2_piobu_direction_output() - gpiochip direction_output |
| */ |
| static int sama5d2_piobu_direction_output(struct gpio_chip *chip, |
| unsigned int pin, int value) |
| { |
| unsigned int val = PIOBU_OUT; |
| |
| if (value) |
| val |= PIOBU_HIGH; |
| |
| return sama5d2_piobu_write_value(chip, pin, PIOBU_DIRECTION | PIOBU_SOD, |
| val); |
| } |
| |
| /** |
| * sama5d2_piobu_get() - gpiochip get |
| */ |
| static int sama5d2_piobu_get(struct gpio_chip *chip, unsigned int pin) |
| { |
| /* if pin is input, read value from PDS else read from SOD */ |
| int ret = sama5d2_piobu_get_direction(chip, pin); |
| |
| if (ret == 1) |
| ret = sama5d2_piobu_read_value(chip, pin, PIOBU_PDS); |
| else if (!ret) |
| ret = sama5d2_piobu_read_value(chip, pin, PIOBU_SOD); |
| |
| if (ret < 0) |
| return ret; |
| |
| return !!ret; |
| } |
| |
| /** |
| * sama5d2_piobu_set() - gpiochip set |
| */ |
| static void sama5d2_piobu_set(struct gpio_chip *chip, unsigned int pin, |
| int value) |
| { |
| if (!value) |
| value = PIOBU_LOW; |
| else |
| value = PIOBU_HIGH; |
| |
| sama5d2_piobu_write_value(chip, pin, PIOBU_SOD, value); |
| } |
| |
| static int sama5d2_piobu_probe(struct platform_device *pdev) |
| { |
| struct sama5d2_piobu *piobu; |
| int ret, i; |
| |
| piobu = devm_kzalloc(&pdev->dev, sizeof(*piobu), GFP_KERNEL); |
| if (!piobu) |
| return -ENOMEM; |
| |
| platform_set_drvdata(pdev, piobu); |
| piobu->chip.label = pdev->name; |
| piobu->chip.parent = &pdev->dev; |
| piobu->chip.of_node = pdev->dev.of_node; |
| piobu->chip.owner = THIS_MODULE, |
| piobu->chip.get_direction = sama5d2_piobu_get_direction, |
| piobu->chip.direction_input = sama5d2_piobu_direction_input, |
| piobu->chip.direction_output = sama5d2_piobu_direction_output, |
| piobu->chip.get = sama5d2_piobu_get, |
| piobu->chip.set = sama5d2_piobu_set, |
| piobu->chip.base = -1, |
| piobu->chip.ngpio = PIOBU_NUM, |
| piobu->chip.can_sleep = 0, |
| |
| piobu->regmap = syscon_node_to_regmap(pdev->dev.of_node); |
| if (IS_ERR(piobu->regmap)) { |
| dev_err(&pdev->dev, "Failed to get syscon regmap %ld\n", |
| PTR_ERR(piobu->regmap)); |
| return PTR_ERR(piobu->regmap); |
| } |
| |
| ret = devm_gpiochip_add_data(&pdev->dev, &piobu->chip, piobu); |
| if (ret) { |
| dev_err(&pdev->dev, "Failed to add gpiochip %d\n", ret); |
| return ret; |
| } |
| |
| for (i = 0; i < PIOBU_NUM; ++i) { |
| ret = sama5d2_piobu_setup_pin(&piobu->chip, i); |
| if (ret) { |
| dev_err(&pdev->dev, "Failed to setup pin: %d %d\n", |
| i, ret); |
| return ret; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static const struct of_device_id sama5d2_piobu_ids[] = { |
| { .compatible = "atmel,sama5d2-secumod" }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, sama5d2_piobu_ids); |
| |
| static struct platform_driver sama5d2_piobu_driver = { |
| .driver = { |
| .name = "sama5d2-piobu", |
| .of_match_table = of_match_ptr(sama5d2_piobu_ids) |
| }, |
| .probe = sama5d2_piobu_probe, |
| }; |
| |
| module_platform_driver(sama5d2_piobu_driver); |
| |
| MODULE_VERSION("1.0"); |
| MODULE_LICENSE("GPL v2"); |
| MODULE_DESCRIPTION("SAMA5D2 PIOBU controller driver"); |
| MODULE_AUTHOR("Andrei Stefanescu <andrei.stefanescu@microchip.com>"); |