diff options
Diffstat (limited to 'drivers/input/misc/max7360-rotary.c')
| -rw-r--r-- | drivers/input/misc/max7360-rotary.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/drivers/input/misc/max7360-rotary.c b/drivers/input/misc/max7360-rotary.c new file mode 100644 index 000000000000..385831ef34b6 --- /dev/null +++ b/drivers/input/misc/max7360-rotary.c @@ -0,0 +1,192 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2025 Bootlin + * + * Author: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com> + */ + +#include <linux/bitfield.h> +#include <linux/device/devres.h> +#include <linux/dev_printk.h> +#include <linux/init.h> +#include <linux/input.h> +#include <linux/interrupt.h> +#include <linux/mfd/max7360.h> +#include <linux/property.h> +#include <linux/platform_device.h> +#include <linux/pm_wakeirq.h> +#include <linux/regmap.h> +#include <linux/types.h> + +#define MAX7360_ROTARY_DEFAULT_STEPS 24 + +struct max7360_rotary { + struct input_dev *input; + struct regmap *regmap; + unsigned int debounce_ms; + + unsigned int pos; + + u32 steps; + u32 axis; + bool relative_axis; + bool rollover; +}; + +static void max7360_rotary_report_event(struct max7360_rotary *max7360_rotary, int steps) +{ + if (max7360_rotary->relative_axis) { + input_report_rel(max7360_rotary->input, max7360_rotary->axis, steps); + } else { + int pos = max7360_rotary->pos; + int maxval = max7360_rotary->steps; + + /* + * Add steps to the position. + * Make sure added steps are always in ]-maxval; maxval[ + * interval, so (pos + maxval) is always >= 0. + * Then set back pos to the [0; maxval[ interval. + */ + pos += steps % maxval; + if (max7360_rotary->rollover) + pos = (pos + maxval) % maxval; + else + pos = clamp(pos, 0, maxval - 1); + + max7360_rotary->pos = pos; + input_report_abs(max7360_rotary->input, max7360_rotary->axis, max7360_rotary->pos); + } + + input_sync(max7360_rotary->input); +} + +static irqreturn_t max7360_rotary_irq(int irq, void *data) +{ + struct max7360_rotary *max7360_rotary = data; + struct device *dev = max7360_rotary->input->dev.parent; + unsigned int val; + int error; + + error = regmap_read(max7360_rotary->regmap, MAX7360_REG_RTR_CNT, &val); + if (error < 0) { + dev_err(dev, "Failed to read rotary counter\n"); + return IRQ_NONE; + } + + if (val == 0) + return IRQ_NONE; + + max7360_rotary_report_event(max7360_rotary, sign_extend32(val, 7)); + + return IRQ_HANDLED; +} + +static int max7360_rotary_hw_init(struct max7360_rotary *max7360_rotary) +{ + struct device *dev = max7360_rotary->input->dev.parent; + int val; + int error; + + val = FIELD_PREP(MAX7360_ROT_DEBOUNCE, max7360_rotary->debounce_ms) | + FIELD_PREP(MAX7360_ROT_INTCNT, 1) | MAX7360_ROT_INTCNT_DLY; + error = regmap_write(max7360_rotary->regmap, MAX7360_REG_RTRCFG, val); + if (error) + dev_err(dev, "Failed to set max7360 rotary encoder configuration\n"); + + return error; +} + +static int max7360_rotary_probe(struct platform_device *pdev) +{ + struct max7360_rotary *max7360_rotary; + struct device *dev = &pdev->dev; + struct input_dev *input; + struct regmap *regmap; + int irq; + int error; + + regmap = dev_get_regmap(dev->parent, NULL); + if (!regmap) + return dev_err_probe(dev, -ENODEV, "Could not get parent regmap\n"); + + irq = fwnode_irq_get_byname(dev_fwnode(dev->parent), "inti"); + if (irq < 0) + return dev_err_probe(dev, irq, "Failed to get IRQ\n"); + + max7360_rotary = devm_kzalloc(dev, sizeof(*max7360_rotary), GFP_KERNEL); + if (!max7360_rotary) + return -ENOMEM; + + max7360_rotary->regmap = regmap; + + device_property_read_u32(dev->parent, "linux,axis", &max7360_rotary->axis); + max7360_rotary->rollover = device_property_read_bool(dev->parent, + "rotary-encoder,rollover"); + max7360_rotary->relative_axis = + device_property_read_bool(dev->parent, "rotary-encoder,relative-axis"); + + error = device_property_read_u32(dev->parent, "rotary-encoder,steps", + &max7360_rotary->steps); + if (error) + max7360_rotary->steps = MAX7360_ROTARY_DEFAULT_STEPS; + + device_property_read_u32(dev->parent, "rotary-debounce-delay-ms", + &max7360_rotary->debounce_ms); + if (max7360_rotary->debounce_ms > MAX7360_ROT_DEBOUNCE_MAX) + return dev_err_probe(dev, -EINVAL, "Invalid debounce timing: %u\n", + max7360_rotary->debounce_ms); + + input = devm_input_allocate_device(dev); + if (!input) + return -ENOMEM; + + max7360_rotary->input = input; + + input->id.bustype = BUS_I2C; + input->name = pdev->name; + + if (max7360_rotary->relative_axis) + input_set_capability(input, EV_REL, max7360_rotary->axis); + else + input_set_abs_params(input, max7360_rotary->axis, 0, max7360_rotary->steps, 0, 1); + + error = devm_request_threaded_irq(dev, irq, NULL, max7360_rotary_irq, + IRQF_ONESHOT | IRQF_SHARED, + "max7360-rotary", max7360_rotary); + if (error) + return dev_err_probe(dev, error, "Failed to register interrupt\n"); + + error = input_register_device(input); + if (error) + return dev_err_probe(dev, error, "Could not register input device\n"); + + error = max7360_rotary_hw_init(max7360_rotary); + if (error) + return dev_err_probe(dev, error, "Failed to initialize max7360 rotary\n"); + + device_init_wakeup(dev, true); + error = dev_pm_set_wake_irq(dev, irq); + if (error) + dev_warn(dev, "Failed to set up wakeup irq: %d\n", error); + + return 0; +} + +static void max7360_rotary_remove(struct platform_device *pdev) +{ + dev_pm_clear_wake_irq(&pdev->dev); + device_init_wakeup(&pdev->dev, false); +} + +static struct platform_driver max7360_rotary_driver = { + .driver = { + .name = "max7360-rotary", + }, + .probe = max7360_rotary_probe, + .remove = max7360_rotary_remove, +}; +module_platform_driver(max7360_rotary_driver); + +MODULE_DESCRIPTION("MAX7360 Rotary driver"); +MODULE_AUTHOR("Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>"); +MODULE_LICENSE("GPL"); |