diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/input/misc/rotary_encoder.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/input/misc/rotary_encoder.c')
-rw-r--r-- | kernel/drivers/input/misc/rotary_encoder.c | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/kernel/drivers/input/misc/rotary_encoder.c b/kernel/drivers/input/misc/rotary_encoder.c new file mode 100644 index 000000000..f27f81ee8 --- /dev/null +++ b/kernel/drivers/input/misc/rotary_encoder.c @@ -0,0 +1,336 @@ +/* + * rotary_encoder.c + * + * (c) 2009 Daniel Mack <daniel@caiaq.de> + * Copyright (C) 2011 Johan Hovold <jhovold@gmail.com> + * + * state machine code inspired by code from Tim Ruetz + * + * A generic driver for rotary encoders connected to GPIO lines. + * See file:Documentation/input/rotary-encoder.txt for more information + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/input.h> +#include <linux/device.h> +#include <linux/platform_device.h> +#include <linux/gpio.h> +#include <linux/rotary_encoder.h> +#include <linux/slab.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/of_gpio.h> + +#define DRV_NAME "rotary-encoder" + +struct rotary_encoder { + struct input_dev *input; + const struct rotary_encoder_platform_data *pdata; + + unsigned int axis; + unsigned int pos; + + unsigned int irq_a; + unsigned int irq_b; + + bool armed; + unsigned char dir; /* 0 - clockwise, 1 - CCW */ + + char last_stable; +}; + +static int rotary_encoder_get_state(const struct rotary_encoder_platform_data *pdata) +{ + int a = !!gpio_get_value(pdata->gpio_a); + int b = !!gpio_get_value(pdata->gpio_b); + + a ^= pdata->inverted_a; + b ^= pdata->inverted_b; + + return ((a << 1) | b); +} + +static void rotary_encoder_report_event(struct rotary_encoder *encoder) +{ + const struct rotary_encoder_platform_data *pdata = encoder->pdata; + + if (pdata->relative_axis) { + input_report_rel(encoder->input, + pdata->axis, encoder->dir ? -1 : 1); + } else { + unsigned int pos = encoder->pos; + + if (encoder->dir) { + /* turning counter-clockwise */ + if (pdata->rollover) + pos += pdata->steps; + if (pos) + pos--; + } else { + /* turning clockwise */ + if (pdata->rollover || pos < pdata->steps) + pos++; + } + + if (pdata->rollover) + pos %= pdata->steps; + + encoder->pos = pos; + input_report_abs(encoder->input, pdata->axis, encoder->pos); + } + + input_sync(encoder->input); +} + +static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) +{ + struct rotary_encoder *encoder = dev_id; + int state; + + state = rotary_encoder_get_state(encoder->pdata); + + switch (state) { + case 0x0: + if (encoder->armed) { + rotary_encoder_report_event(encoder); + encoder->armed = false; + } + break; + + case 0x1: + case 0x2: + if (encoder->armed) + encoder->dir = state - 1; + break; + + case 0x3: + encoder->armed = true; + break; + } + + return IRQ_HANDLED; +} + +static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id) +{ + struct rotary_encoder *encoder = dev_id; + int state; + + state = rotary_encoder_get_state(encoder->pdata); + + switch (state) { + case 0x00: + case 0x03: + if (state != encoder->last_stable) { + rotary_encoder_report_event(encoder); + encoder->last_stable = state; + } + break; + + case 0x01: + case 0x02: + encoder->dir = (encoder->last_stable + state) & 0x01; + break; + } + + return IRQ_HANDLED; +} + +#ifdef CONFIG_OF +static const struct of_device_id rotary_encoder_of_match[] = { + { .compatible = "rotary-encoder", }, + { }, +}; +MODULE_DEVICE_TABLE(of, rotary_encoder_of_match); + +static struct rotary_encoder_platform_data *rotary_encoder_parse_dt(struct device *dev) +{ + const struct of_device_id *of_id = + of_match_device(rotary_encoder_of_match, dev); + struct device_node *np = dev->of_node; + struct rotary_encoder_platform_data *pdata; + enum of_gpio_flags flags; + + if (!of_id || !np) + return NULL; + + pdata = kzalloc(sizeof(struct rotary_encoder_platform_data), + GFP_KERNEL); + if (!pdata) + return ERR_PTR(-ENOMEM); + + of_property_read_u32(np, "rotary-encoder,steps", &pdata->steps); + of_property_read_u32(np, "linux,axis", &pdata->axis); + + pdata->gpio_a = of_get_gpio_flags(np, 0, &flags); + pdata->inverted_a = flags & OF_GPIO_ACTIVE_LOW; + + pdata->gpio_b = of_get_gpio_flags(np, 1, &flags); + pdata->inverted_b = flags & OF_GPIO_ACTIVE_LOW; + + pdata->relative_axis = !!of_get_property(np, + "rotary-encoder,relative-axis", NULL); + pdata->rollover = !!of_get_property(np, + "rotary-encoder,rollover", NULL); + pdata->half_period = !!of_get_property(np, + "rotary-encoder,half-period", NULL); + + return pdata; +} +#else +static inline struct rotary_encoder_platform_data * +rotary_encoder_parse_dt(struct device *dev) +{ + return NULL; +} +#endif + +static int rotary_encoder_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + const struct rotary_encoder_platform_data *pdata = dev_get_platdata(dev); + struct rotary_encoder *encoder; + struct input_dev *input; + irq_handler_t handler; + int err; + + if (!pdata) { + pdata = rotary_encoder_parse_dt(dev); + if (IS_ERR(pdata)) + return PTR_ERR(pdata); + + if (!pdata) { + dev_err(dev, "missing platform data\n"); + return -EINVAL; + } + } + + encoder = kzalloc(sizeof(struct rotary_encoder), GFP_KERNEL); + input = input_allocate_device(); + if (!encoder || !input) { + err = -ENOMEM; + goto exit_free_mem; + } + + encoder->input = input; + encoder->pdata = pdata; + + input->name = pdev->name; + input->id.bustype = BUS_HOST; + input->dev.parent = dev; + + if (pdata->relative_axis) { + input->evbit[0] = BIT_MASK(EV_REL); + input->relbit[0] = BIT_MASK(pdata->axis); + } else { + input->evbit[0] = BIT_MASK(EV_ABS); + input_set_abs_params(encoder->input, + pdata->axis, 0, pdata->steps, 0, 1); + } + + /* request the GPIOs */ + err = gpio_request_one(pdata->gpio_a, GPIOF_IN, dev_name(dev)); + if (err) { + dev_err(dev, "unable to request GPIO %d\n", pdata->gpio_a); + goto exit_free_mem; + } + + err = gpio_request_one(pdata->gpio_b, GPIOF_IN, dev_name(dev)); + if (err) { + dev_err(dev, "unable to request GPIO %d\n", pdata->gpio_b); + goto exit_free_gpio_a; + } + + encoder->irq_a = gpio_to_irq(pdata->gpio_a); + encoder->irq_b = gpio_to_irq(pdata->gpio_b); + + /* request the IRQs */ + if (pdata->half_period) { + handler = &rotary_encoder_half_period_irq; + encoder->last_stable = rotary_encoder_get_state(pdata); + } else { + handler = &rotary_encoder_irq; + } + + err = request_irq(encoder->irq_a, handler, + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, + DRV_NAME, encoder); + if (err) { + dev_err(dev, "unable to request IRQ %d\n", encoder->irq_a); + goto exit_free_gpio_b; + } + + err = request_irq(encoder->irq_b, handler, + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, + DRV_NAME, encoder); + if (err) { + dev_err(dev, "unable to request IRQ %d\n", encoder->irq_b); + goto exit_free_irq_a; + } + + err = input_register_device(input); + if (err) { + dev_err(dev, "failed to register input device\n"); + goto exit_free_irq_b; + } + + platform_set_drvdata(pdev, encoder); + + return 0; + +exit_free_irq_b: + free_irq(encoder->irq_b, encoder); +exit_free_irq_a: + free_irq(encoder->irq_a, encoder); +exit_free_gpio_b: + gpio_free(pdata->gpio_b); +exit_free_gpio_a: + gpio_free(pdata->gpio_a); +exit_free_mem: + input_free_device(input); + kfree(encoder); + if (!dev_get_platdata(&pdev->dev)) + kfree(pdata); + + return err; +} + +static int rotary_encoder_remove(struct platform_device *pdev) +{ + struct rotary_encoder *encoder = platform_get_drvdata(pdev); + const struct rotary_encoder_platform_data *pdata = encoder->pdata; + + free_irq(encoder->irq_a, encoder); + free_irq(encoder->irq_b, encoder); + gpio_free(pdata->gpio_a); + gpio_free(pdata->gpio_b); + + input_unregister_device(encoder->input); + kfree(encoder); + + if (!dev_get_platdata(&pdev->dev)) + kfree(pdata); + + return 0; +} + +static struct platform_driver rotary_encoder_driver = { + .probe = rotary_encoder_probe, + .remove = rotary_encoder_remove, + .driver = { + .name = DRV_NAME, + .of_match_table = of_match_ptr(rotary_encoder_of_match), + } +}; +module_platform_driver(rotary_encoder_driver); + +MODULE_ALIAS("platform:" DRV_NAME); +MODULE_DESCRIPTION("GPIO rotary encoder driver"); +MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>, Johan Hovold"); +MODULE_LICENSE("GPL v2"); |