diff options
Diffstat (limited to 'drivers/pinctrl/pinctrl-apple-gpio.c')
-rw-r--r-- | drivers/pinctrl/pinctrl-apple-gpio.c | 531 |
1 files changed, 531 insertions, 0 deletions
diff --git a/drivers/pinctrl/pinctrl-apple-gpio.c b/drivers/pinctrl/pinctrl-apple-gpio.c new file mode 100644 index 0000000000..3751c7de37 --- /dev/null +++ b/drivers/pinctrl/pinctrl-apple-gpio.c @@ -0,0 +1,531 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Apple SoC pinctrl+GPIO+external IRQ driver + * + * Copyright (C) The Asahi Linux Contributors + * Copyright (C) 2020 Corellium LLC + * + * Based on: pinctrl-pistachio.c + * Copyright (C) 2014 Imagination Technologies Ltd. + * Copyright (C) 2014 Google, Inc. + */ + +#include <dt-bindings/pinctrl/apple.h> + +#include <linux/bitfield.h> +#include <linux/bits.h> +#include <linux/gpio/driver.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_irq.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#include <linux/pinctrl/pinctrl.h> +#include <linux/pinctrl/pinmux.h> + +#include "pinctrl-utils.h" +#include "core.h" +#include "pinmux.h" + +struct apple_gpio_pinctrl { + struct device *dev; + struct pinctrl_dev *pctldev; + + void __iomem *base; + struct regmap *map; + + struct pinctrl_desc pinctrl_desc; + struct gpio_chip gpio_chip; + u8 irqgrps[]; +}; + +#define REG_GPIO(x) (4 * (x)) +#define REG_GPIOx_DATA BIT(0) +#define REG_GPIOx_MODE GENMASK(3, 1) +#define REG_GPIOx_OUT 1 +#define REG_GPIOx_IN_IRQ_HI 2 +#define REG_GPIOx_IN_IRQ_LO 3 +#define REG_GPIOx_IN_IRQ_UP 4 +#define REG_GPIOx_IN_IRQ_DN 5 +#define REG_GPIOx_IN_IRQ_ANY 6 +#define REG_GPIOx_IN_IRQ_OFF 7 +#define REG_GPIOx_PERIPH GENMASK(6, 5) +#define REG_GPIOx_PULL GENMASK(8, 7) +#define REG_GPIOx_PULL_OFF 0 +#define REG_GPIOx_PULL_DOWN 1 +#define REG_GPIOx_PULL_UP_STRONG 2 +#define REG_GPIOx_PULL_UP 3 +#define REG_GPIOx_INPUT_ENABLE BIT(9) +#define REG_GPIOx_DRIVE_STRENGTH0 GENMASK(11, 10) +#define REG_GPIOx_SCHMITT BIT(15) +#define REG_GPIOx_GRP GENMASK(18, 16) +#define REG_GPIOx_LOCK BIT(21) +#define REG_GPIOx_DRIVE_STRENGTH1 GENMASK(23, 22) +#define REG_IRQ(g, x) (0x800 + 0x40 * (g) + 4 * ((x) >> 5)) + +struct regmap_config regmap_config = { + .reg_bits = 32, + .val_bits = 32, + .reg_stride = 4, + .cache_type = REGCACHE_FLAT, + .max_register = 512 * sizeof(u32), + .num_reg_defaults_raw = 512, + .use_relaxed_mmio = true, + .use_raw_spinlock = true, +}; + +/* No locking needed to mask/unmask IRQs as the interrupt mode is per pin-register. */ +static void apple_gpio_set_reg(struct apple_gpio_pinctrl *pctl, + unsigned int pin, u32 mask, u32 value) +{ + regmap_update_bits(pctl->map, REG_GPIO(pin), mask, value); +} + +static u32 apple_gpio_get_reg(struct apple_gpio_pinctrl *pctl, + unsigned int pin) +{ + int ret; + u32 val; + + ret = regmap_read(pctl->map, REG_GPIO(pin), &val); + if (ret) + return 0; + + return val; +} + +/* Pin controller functions */ + +static int apple_gpio_dt_node_to_map(struct pinctrl_dev *pctldev, + struct device_node *node, + struct pinctrl_map **map, + unsigned *num_maps) +{ + unsigned reserved_maps; + struct apple_gpio_pinctrl *pctl; + u32 pinfunc, pin, func; + int num_pins, i, ret; + const char *group_name; + const char *function_name; + + *map = NULL; + *num_maps = 0; + reserved_maps = 0; + + pctl = pinctrl_dev_get_drvdata(pctldev); + + ret = of_property_count_u32_elems(node, "pinmux"); + if (ret <= 0) { + dev_err(pctl->dev, + "missing or empty pinmux property in node %pOFn.\n", + node); + return ret ? ret : -EINVAL; + } + + num_pins = ret; + + ret = pinctrl_utils_reserve_map(pctldev, map, &reserved_maps, num_maps, num_pins); + if (ret) + return ret; + + for (i = 0; i < num_pins; i++) { + ret = of_property_read_u32_index(node, "pinmux", i, &pinfunc); + if (ret) + goto free_map; + + pin = APPLE_PIN(pinfunc); + func = APPLE_FUNC(pinfunc); + + if (func >= pinmux_generic_get_function_count(pctldev)) { + ret = -EINVAL; + goto free_map; + } + + group_name = pinctrl_generic_get_group_name(pctldev, pin); + function_name = pinmux_generic_get_function_name(pctl->pctldev, func); + ret = pinctrl_utils_add_map_mux(pctl->pctldev, map, + &reserved_maps, num_maps, + group_name, function_name); + if (ret) + goto free_map; + } + +free_map: + if (ret < 0) + pinctrl_utils_free_map(pctldev, *map, *num_maps); + + return ret; +} + +static const struct pinctrl_ops apple_gpio_pinctrl_ops = { + .get_groups_count = pinctrl_generic_get_group_count, + .get_group_name = pinctrl_generic_get_group_name, + .get_group_pins = pinctrl_generic_get_group_pins, + .dt_node_to_map = apple_gpio_dt_node_to_map, + .dt_free_map = pinctrl_utils_free_map, +}; + +/* Pin multiplexer functions */ + +static int apple_gpio_pinmux_set(struct pinctrl_dev *pctldev, unsigned func, + unsigned group) +{ + struct apple_gpio_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev); + + apple_gpio_set_reg( + pctl, group, REG_GPIOx_PERIPH | REG_GPIOx_INPUT_ENABLE, + FIELD_PREP(REG_GPIOx_PERIPH, func) | REG_GPIOx_INPUT_ENABLE); + + return 0; +} + +static const struct pinmux_ops apple_gpio_pinmux_ops = { + .get_functions_count = pinmux_generic_get_function_count, + .get_function_name = pinmux_generic_get_function_name, + .get_function_groups = pinmux_generic_get_function_groups, + .set_mux = apple_gpio_pinmux_set, + .strict = true, +}; + +/* GPIO chip functions */ + +static int apple_gpio_get_direction(struct gpio_chip *chip, unsigned int offset) +{ + struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip); + unsigned int reg = apple_gpio_get_reg(pctl, offset); + + if (FIELD_GET(REG_GPIOx_MODE, reg) == REG_GPIOx_OUT) + return GPIO_LINE_DIRECTION_OUT; + return GPIO_LINE_DIRECTION_IN; +} + +static int apple_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip); + unsigned int reg = apple_gpio_get_reg(pctl, offset); + + /* + * If this is an input GPIO, read the actual value (not the + * cached regmap value) + */ + if (FIELD_GET(REG_GPIOx_MODE, reg) != REG_GPIOx_OUT) + reg = readl_relaxed(pctl->base + REG_GPIO(offset)); + + return !!(reg & REG_GPIOx_DATA); +} + +static void apple_gpio_set(struct gpio_chip *chip, unsigned int offset, int value) +{ + struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip); + + apple_gpio_set_reg(pctl, offset, REG_GPIOx_DATA, value ? REG_GPIOx_DATA : 0); +} + +static int apple_gpio_direction_input(struct gpio_chip *chip, unsigned int offset) +{ + struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip); + + apple_gpio_set_reg(pctl, offset, + REG_GPIOx_PERIPH | REG_GPIOx_MODE | REG_GPIOx_DATA | + REG_GPIOx_INPUT_ENABLE, + FIELD_PREP(REG_GPIOx_MODE, REG_GPIOx_IN_IRQ_OFF) | + REG_GPIOx_INPUT_ENABLE); + return 0; +} + +static int apple_gpio_direction_output(struct gpio_chip *chip, + unsigned int offset, int value) +{ + struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip); + + apple_gpio_set_reg(pctl, offset, + REG_GPIOx_PERIPH | REG_GPIOx_MODE | REG_GPIOx_DATA, + FIELD_PREP(REG_GPIOx_MODE, REG_GPIOx_OUT) | + (value ? REG_GPIOx_DATA : 0)); + return 0; +} + +/* IRQ chip functions */ + +static void apple_gpio_irq_ack(struct irq_data *data) +{ + struct apple_gpio_pinctrl *pctl = gpiochip_get_data(irq_data_get_irq_chip_data(data)); + unsigned int irqgrp = FIELD_GET(REG_GPIOx_GRP, apple_gpio_get_reg(pctl, data->hwirq)); + + writel(BIT(data->hwirq % 32), pctl->base + REG_IRQ(irqgrp, data->hwirq)); +} + +static unsigned int apple_gpio_irq_type(unsigned int type) +{ + switch (type & IRQ_TYPE_SENSE_MASK) { + case IRQ_TYPE_EDGE_RISING: + return REG_GPIOx_IN_IRQ_UP; + case IRQ_TYPE_EDGE_FALLING: + return REG_GPIOx_IN_IRQ_DN; + case IRQ_TYPE_EDGE_BOTH: + return REG_GPIOx_IN_IRQ_ANY; + case IRQ_TYPE_LEVEL_HIGH: + return REG_GPIOx_IN_IRQ_HI; + case IRQ_TYPE_LEVEL_LOW: + return REG_GPIOx_IN_IRQ_LO; + default: + return REG_GPIOx_IN_IRQ_OFF; + } +} + +static void apple_gpio_irq_mask(struct irq_data *data) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + struct apple_gpio_pinctrl *pctl = gpiochip_get_data(gc); + + apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_MODE, + FIELD_PREP(REG_GPIOx_MODE, REG_GPIOx_IN_IRQ_OFF)); + gpiochip_disable_irq(gc, data->hwirq); +} + +static void apple_gpio_irq_unmask(struct irq_data *data) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + struct apple_gpio_pinctrl *pctl = gpiochip_get_data(gc); + unsigned int irqtype = apple_gpio_irq_type(irqd_get_trigger_type(data)); + + gpiochip_enable_irq(gc, data->hwirq); + apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_MODE, + FIELD_PREP(REG_GPIOx_MODE, irqtype)); +} + +static unsigned int apple_gpio_irq_startup(struct irq_data *data) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(data); + struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip); + + apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_GRP, + FIELD_PREP(REG_GPIOx_GRP, 0)); + + apple_gpio_direction_input(chip, data->hwirq); + apple_gpio_irq_unmask(data); + + return 0; +} + +static int apple_gpio_irq_set_type(struct irq_data *data, unsigned int type) +{ + struct apple_gpio_pinctrl *pctl = gpiochip_get_data(irq_data_get_irq_chip_data(data)); + unsigned int irqtype = apple_gpio_irq_type(type); + + if (irqtype == REG_GPIOx_IN_IRQ_OFF) + return -EINVAL; + + apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_MODE, + FIELD_PREP(REG_GPIOx_MODE, irqtype)); + + if (type & IRQ_TYPE_LEVEL_MASK) + irq_set_handler_locked(data, handle_level_irq); + else + irq_set_handler_locked(data, handle_edge_irq); + return 0; +} + +static void apple_gpio_irq_handler(struct irq_desc *desc) +{ + struct irq_chip *chip = irq_desc_get_chip(desc); + u8 *grpp = irq_desc_get_handler_data(desc); + struct apple_gpio_pinctrl *pctl; + unsigned int pinh, pinl; + unsigned long pending; + struct gpio_chip *gc; + + pctl = container_of(grpp - *grpp, typeof(*pctl), irqgrps[0]); + gc = &pctl->gpio_chip; + + chained_irq_enter(chip, desc); + for (pinh = 0; pinh < gc->ngpio; pinh += 32) { + pending = readl_relaxed(pctl->base + REG_IRQ(*grpp, pinh)); + for_each_set_bit(pinl, &pending, 32) + generic_handle_domain_irq(gc->irq.domain, pinh + pinl); + } + chained_irq_exit(chip, desc); +} + +static const struct irq_chip apple_gpio_irqchip = { + .name = "Apple-GPIO", + .irq_startup = apple_gpio_irq_startup, + .irq_ack = apple_gpio_irq_ack, + .irq_mask = apple_gpio_irq_mask, + .irq_unmask = apple_gpio_irq_unmask, + .irq_set_type = apple_gpio_irq_set_type, + .flags = IRQCHIP_IMMUTABLE, + GPIOCHIP_IRQ_RESOURCE_HELPERS, +}; + +/* Probe & register */ + +static int apple_gpio_register(struct apple_gpio_pinctrl *pctl) +{ + struct gpio_irq_chip *girq = &pctl->gpio_chip.irq; + void **irq_data = NULL; + int ret; + + pctl->gpio_chip.label = dev_name(pctl->dev); + pctl->gpio_chip.request = gpiochip_generic_request; + pctl->gpio_chip.free = gpiochip_generic_free; + pctl->gpio_chip.get_direction = apple_gpio_get_direction; + pctl->gpio_chip.direction_input = apple_gpio_direction_input; + pctl->gpio_chip.direction_output = apple_gpio_direction_output; + pctl->gpio_chip.get = apple_gpio_get; + pctl->gpio_chip.set = apple_gpio_set; + pctl->gpio_chip.base = -1; + pctl->gpio_chip.ngpio = pctl->pinctrl_desc.npins; + pctl->gpio_chip.parent = pctl->dev; + + if (girq->num_parents) { + int i; + + gpio_irq_chip_set_chip(girq, &apple_gpio_irqchip); + girq->parent_handler = apple_gpio_irq_handler; + + girq->parents = kmalloc_array(girq->num_parents, + sizeof(*girq->parents), + GFP_KERNEL); + irq_data = kmalloc_array(girq->num_parents, sizeof(*irq_data), + GFP_KERNEL); + if (!girq->parents || !irq_data) { + ret = -ENOMEM; + goto out_free_irq_data; + } + + for (i = 0; i < girq->num_parents; i++) { + ret = platform_get_irq(to_platform_device(pctl->dev), i); + if (ret < 0) + goto out_free_irq_data; + + girq->parents[i] = ret; + pctl->irqgrps[i] = i; + irq_data[i] = &pctl->irqgrps[i]; + } + + girq->parent_handler_data_array = irq_data; + girq->per_parent_data = true; + girq->default_type = IRQ_TYPE_NONE; + girq->handler = handle_level_irq; + } + + ret = devm_gpiochip_add_data(pctl->dev, &pctl->gpio_chip, pctl); + +out_free_irq_data: + kfree(girq->parents); + kfree(irq_data); + + return ret; +} + +static int apple_gpio_pinctrl_probe(struct platform_device *pdev) +{ + struct apple_gpio_pinctrl *pctl; + struct pinctrl_pin_desc *pins; + unsigned int npins; + const char **pin_names; + unsigned int *pin_nums; + static const char* pinmux_functions[] = { + "gpio", "periph1", "periph2", "periph3" + }; + unsigned int i, nirqs = 0; + int res; + + if (of_property_read_bool(pdev->dev.of_node, "interrupt-controller")) { + res = platform_irq_count(pdev); + if (res > 0) + nirqs = res; + } + + pctl = devm_kzalloc(&pdev->dev, struct_size(pctl, irqgrps, nirqs), + GFP_KERNEL); + if (!pctl) + return -ENOMEM; + pctl->dev = &pdev->dev; + pctl->gpio_chip.irq.num_parents = nirqs; + dev_set_drvdata(&pdev->dev, pctl); + + if (of_property_read_u32(pdev->dev.of_node, "apple,npins", &npins)) + return dev_err_probe(&pdev->dev, -EINVAL, + "apple,npins property not found\n"); + + pins = devm_kmalloc_array(&pdev->dev, npins, sizeof(pins[0]), + GFP_KERNEL); + pin_names = devm_kmalloc_array(&pdev->dev, npins, sizeof(pin_names[0]), + GFP_KERNEL); + pin_nums = devm_kmalloc_array(&pdev->dev, npins, sizeof(pin_nums[0]), + GFP_KERNEL); + if (!pins || !pin_names || !pin_nums) + return -ENOMEM; + + pctl->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(pctl->base)) + return PTR_ERR(pctl->base); + + pctl->map = devm_regmap_init_mmio(&pdev->dev, pctl->base, ®map_config); + if (IS_ERR(pctl->map)) + return dev_err_probe(&pdev->dev, PTR_ERR(pctl->map), + "Failed to create regmap\n"); + + for (i = 0; i < npins; i++) { + pins[i].number = i; + pins[i].name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "PIN%u", i); + pins[i].drv_data = pctl; + pin_names[i] = pins[i].name; + pin_nums[i] = i; + } + + pctl->pinctrl_desc.name = dev_name(pctl->dev); + pctl->pinctrl_desc.pins = pins; + pctl->pinctrl_desc.npins = npins; + pctl->pinctrl_desc.pctlops = &apple_gpio_pinctrl_ops; + pctl->pinctrl_desc.pmxops = &apple_gpio_pinmux_ops; + + pctl->pctldev = devm_pinctrl_register(&pdev->dev, &pctl->pinctrl_desc, pctl); + if (IS_ERR(pctl->pctldev)) + return dev_err_probe(&pdev->dev, PTR_ERR(pctl->pctldev), + "Failed to register pinctrl device.\n"); + + for (i = 0; i < npins; i++) { + res = pinctrl_generic_add_group(pctl->pctldev, pins[i].name, + pin_nums + i, 1, pctl); + if (res < 0) + return dev_err_probe(pctl->dev, res, + "Failed to register group"); + } + + for (i = 0; i < ARRAY_SIZE(pinmux_functions); ++i) { + res = pinmux_generic_add_function(pctl->pctldev, pinmux_functions[i], + pin_names, npins, pctl); + if (res < 0) + return dev_err_probe(pctl->dev, res, + "Failed to register function."); + } + + return apple_gpio_register(pctl); +} + +static const struct of_device_id apple_gpio_pinctrl_of_match[] = { + { .compatible = "apple,pinctrl", }, + { } +}; +MODULE_DEVICE_TABLE(of, apple_gpio_pinctrl_of_match); + +static struct platform_driver apple_gpio_pinctrl_driver = { + .driver = { + .name = "apple-gpio-pinctrl", + .of_match_table = apple_gpio_pinctrl_of_match, + .suppress_bind_attrs = true, + }, + .probe = apple_gpio_pinctrl_probe, +}; +module_platform_driver(apple_gpio_pinctrl_driver); + +MODULE_DESCRIPTION("Apple pinctrl/GPIO driver"); +MODULE_AUTHOR("Stan Skowronek <stan@corellium.com>"); +MODULE_AUTHOR("Joey Gouly <joey.gouly@arm.com>"); +MODULE_LICENSE("GPL v2"); |