diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-07 09:12:19 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-07 09:12:19 -0700 |
commit | d4e65476bc68dbc9231b3c772b71f1576579b6fb (patch) | |
tree | 3408d0e17d8ea6bdfaa9c5cd5745298d5b7e67a3 /drivers/input/misc/gpio_decoder.c | |
parent | d042380886fb2fc6c4b0fcfe1214ba473769a8e9 (diff) | |
parent | c758f96a8c346ac5a6822b521ec92308c5774381 (diff) |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input subsystem updates from Dmitry Torokhov:
"You will get
- a new driver for Elan eKTF2127 touchscreen controllers
- a new "gpio-decoder" driver to read and report state of several
GPIO lines
- an ADC resistor ladder driver
- the ft6326 driver is removed because edt-ft5x06 handles the same
devices just fine.
.. plus the regular slew of driver fixes/enhancements"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (26 commits)
Input: elan_i2c - fix return tests of i2c_smbus_read_block_data()
Input: ektf2127 - mark PM functions as __maybe_unused
Input: snvs_pwrkey - drop input_free_device call if input_register_device fails
Input: add support for Elan eKTF2127 touchscreen controller
Input: serio - add hangup support
Input: tps65218-pwrbutton - add support for tps65217 variant
Input: jornada720_ts - get rid of mach/irqs.h and mach/hardware.h includes
Input: jornada720_kbd - remove unneeded mach/hardware.h include
Input: focaltech - mark focaltech_set_resolution() static
Input: wdt87xx_i2c - fix the flash erase issue
Input: gpio-keys-polled - don't use unit-address with button nodes
Input: add generic input driver to read encoded GPIO lines
Input: add ADC resistor ladder driver
Input: pegasus_notetaker - directly include workqueue header
Input: elants_i2c - get product id on recovery mode for FW update
Input: wm97xx - remove deprecated create_singletheread_workqueue
Input: mc13783_ts - remove deprecated create_singletheread_workqueue
Input: psmouse - remove deprecated create_singletheread_workqueue
Input: jornada720_kbd - switch to using dev_dbg
Input: jornada720_kbd - get rid of mach/irqs.h include
...
Diffstat (limited to 'drivers/input/misc/gpio_decoder.c')
-rw-r--r-- | drivers/input/misc/gpio_decoder.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/drivers/input/misc/gpio_decoder.c b/drivers/input/misc/gpio_decoder.c new file mode 100644 index 000000000000..ca7e0bacb2d8 --- /dev/null +++ b/drivers/input/misc/gpio_decoder.c @@ -0,0 +1,137 @@ +/* + * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/ + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * A generic driver to read multiple gpio lines and translate the + * encoded numeric value into an input event. + */ + +#include <linux/device.h> +#include <linux/gpio/consumer.h> +#include <linux/input.h> +#include <linux/input-polldev.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> + +struct gpio_decoder { + struct input_polled_dev *poll_dev; + struct gpio_descs *input_gpios; + struct device *dev; + u32 axis; + u32 last_stable; +}; + +static int gpio_decoder_get_gpios_state(struct gpio_decoder *decoder) +{ + struct gpio_descs *gpios = decoder->input_gpios; + unsigned int ret = 0; + int i, val; + + for (i = 0; i < gpios->ndescs; i++) { + val = gpiod_get_value_cansleep(gpios->desc[i]); + if (val < 0) { + dev_err(decoder->dev, + "Error reading gpio %d: %d\n", + desc_to_gpio(gpios->desc[i]), val); + return val; + } + + val = !!val; + ret = (ret << 1) | val; + } + + return ret; +} + +static void gpio_decoder_poll_gpios(struct input_polled_dev *poll_dev) +{ + struct gpio_decoder *decoder = poll_dev->private; + int state; + + state = gpio_decoder_get_gpios_state(decoder); + if (state >= 0 && state != decoder->last_stable) { + input_report_abs(poll_dev->input, decoder->axis, state); + input_sync(poll_dev->input); + decoder->last_stable = state; + } +} + +static int gpio_decoder_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct gpio_decoder *decoder; + struct input_polled_dev *poll_dev; + u32 max; + int err; + + decoder = devm_kzalloc(dev, sizeof(struct gpio_decoder), GFP_KERNEL); + if (!decoder) + return -ENOMEM; + + device_property_read_u32(dev, "linux,axis", &decoder->axis); + decoder->input_gpios = devm_gpiod_get_array(dev, NULL, GPIOD_IN); + if (IS_ERR(decoder->input_gpios)) { + dev_err(dev, "unable to acquire input gpios\n"); + return PTR_ERR(decoder->input_gpios); + } + if (decoder->input_gpios->ndescs < 2) { + dev_err(dev, "not enough gpios found\n"); + return -EINVAL; + } + + if (device_property_read_u32(dev, "decoder-max-value", &max)) + max = (1U << decoder->input_gpios->ndescs) - 1; + + decoder->dev = dev; + poll_dev = devm_input_allocate_polled_device(decoder->dev); + if (!poll_dev) + return -ENOMEM; + + poll_dev->private = decoder; + poll_dev->poll = gpio_decoder_poll_gpios; + decoder->poll_dev = poll_dev; + + poll_dev->input->name = pdev->name; + poll_dev->input->id.bustype = BUS_HOST; + input_set_abs_params(poll_dev->input, decoder->axis, 0, max, 0, 0); + + err = input_register_polled_device(poll_dev); + if (err) { + dev_err(dev, "failed to register polled device\n"); + return err; + } + platform_set_drvdata(pdev, decoder); + + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id gpio_decoder_of_match[] = { + { .compatible = "gpio-decoder", }, + { }, +}; +MODULE_DEVICE_TABLE(of, gpio_decoder_of_match); +#endif + +static struct platform_driver gpio_decoder_driver = { + .probe = gpio_decoder_probe, + .driver = { + .name = "gpio-decoder", + .of_match_table = of_match_ptr(gpio_decoder_of_match), + } +}; +module_platform_driver(gpio_decoder_driver); + +MODULE_DESCRIPTION("GPIO decoder input driver"); +MODULE_AUTHOR("Vignesh R <vigneshr@ti.com>"); +MODULE_LICENSE("GPL v2"); |