diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-05 11:08:17 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-05 11:08:17 -0700 |
commit | bafb0762cb6a906eb4105cccfb3bcd90be7f40d2 (patch) | |
tree | 14ecb87c33bcf909e5b95c27cd694ded4ac1478c /drivers/mux/gpio.c | |
parent | 44b1671fae88ce95b8c7b53acbc6ba71ca67db00 (diff) | |
parent | 3a6430ce462172caac7c73f4afd550ab0f105737 (diff) |
Merge tag 'char-misc-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver updates from Greg KH:
"Here is the big char/misc driver update for 4.14-rc1.
Lots of different stuff in here, it's been an active development cycle
for some reason. Highlights are:
- updated binder driver, this brings binder up to date with what
shipped in the Android O release, plus some more changes that
happened since then that are in the Android development trees.
- coresight updates and fixes
- mux driver file renames to be a bit "nicer"
- intel_th driver updates
- normal set of hyper-v updates and changes
- small fpga subsystem and driver updates
- lots of const code changes all over the driver trees
- extcon driver updates
- fmc driver subsystem upadates
- w1 subsystem minor reworks and new features and drivers added
- spmi driver updates
Plus a smattering of other minor driver updates and fixes.
All of these have been in linux-next with no reported issues for a
while"
* tag 'char-misc-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (244 commits)
ANDROID: binder: don't queue async transactions to thread.
ANDROID: binder: don't enqueue death notifications to thread todo.
ANDROID: binder: Don't BUG_ON(!spin_is_locked()).
ANDROID: binder: Add BINDER_GET_NODE_DEBUG_INFO ioctl
ANDROID: binder: push new transactions to waiting threads.
ANDROID: binder: remove proc waitqueue
android: binder: Add page usage in binder stats
android: binder: fixup crash introduced by moving buffer hdr
drivers: w1: add hwmon temp support for w1_therm
drivers: w1: refactor w1_slave_show to make the temp reading functionality separate
drivers: w1: add hwmon support structures
eeprom: idt_89hpesx: Support both ACPI and OF probing
mcb: Fix an error handling path in 'chameleon_parse_cells()'
MCB: add support for SC31 to mcb-lpc
mux: make device_type const
char: virtio: constify attribute_group structures.
Documentation/ABI: document the nvmem sysfs files
lkdtm: fix spelling mistake: "incremeted" -> "incremented"
perf: cs-etm: Fix ETMv4 CONFIGR entry in perf.data file
nvmem: include linux/err.h from header
...
Diffstat (limited to 'drivers/mux/gpio.c')
-rw-r--r-- | drivers/mux/gpio.c | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/drivers/mux/gpio.c b/drivers/mux/gpio.c new file mode 100644 index 000000000000..468bf1709606 --- /dev/null +++ b/drivers/mux/gpio.c @@ -0,0 +1,114 @@ +/* + * GPIO-controlled multiplexer driver + * + * Copyright (C) 2017 Axentia Technologies AB + * + * Author: Peter Rosin <peda@axentia.se> + * + * 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/err.h> +#include <linux/gpio/consumer.h> +#include <linux/module.h> +#include <linux/mux/driver.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/property.h> + +struct mux_gpio { + struct gpio_descs *gpios; + int *val; +}; + +static int mux_gpio_set(struct mux_control *mux, int state) +{ + struct mux_gpio *mux_gpio = mux_chip_priv(mux->chip); + int i; + + for (i = 0; i < mux_gpio->gpios->ndescs; i++) + mux_gpio->val[i] = (state >> i) & 1; + + gpiod_set_array_value_cansleep(mux_gpio->gpios->ndescs, + mux_gpio->gpios->desc, + mux_gpio->val); + + return 0; +} + +static const struct mux_control_ops mux_gpio_ops = { + .set = mux_gpio_set, +}; + +static const struct of_device_id mux_gpio_dt_ids[] = { + { .compatible = "gpio-mux", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, mux_gpio_dt_ids); + +static int mux_gpio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct mux_chip *mux_chip; + struct mux_gpio *mux_gpio; + int pins; + s32 idle_state; + int ret; + + pins = gpiod_count(dev, "mux"); + if (pins < 0) + return pins; + + mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*mux_gpio) + + pins * sizeof(*mux_gpio->val)); + if (IS_ERR(mux_chip)) + return PTR_ERR(mux_chip); + + mux_gpio = mux_chip_priv(mux_chip); + mux_gpio->val = (int *)(mux_gpio + 1); + mux_chip->ops = &mux_gpio_ops; + + mux_gpio->gpios = devm_gpiod_get_array(dev, "mux", GPIOD_OUT_LOW); + if (IS_ERR(mux_gpio->gpios)) { + ret = PTR_ERR(mux_gpio->gpios); + if (ret != -EPROBE_DEFER) + dev_err(dev, "failed to get gpios\n"); + return ret; + } + WARN_ON(pins != mux_gpio->gpios->ndescs); + mux_chip->mux->states = 1 << pins; + + ret = device_property_read_u32(dev, "idle-state", (u32 *)&idle_state); + if (ret >= 0 && idle_state != MUX_IDLE_AS_IS) { + if (idle_state < 0 || idle_state >= mux_chip->mux->states) { + dev_err(dev, "invalid idle-state %u\n", idle_state); + return -EINVAL; + } + + mux_chip->mux->idle_state = idle_state; + } + + ret = devm_mux_chip_register(dev, mux_chip); + if (ret < 0) + return ret; + + dev_info(dev, "%u-way mux-controller registered\n", + mux_chip->mux->states); + + return 0; +} + +static struct platform_driver mux_gpio_driver = { + .driver = { + .name = "gpio-mux", + .of_match_table = of_match_ptr(mux_gpio_dt_ids), + }, + .probe = mux_gpio_probe, +}; +module_platform_driver(mux_gpio_driver); + +MODULE_DESCRIPTION("GPIO-controlled multiplexer driver"); +MODULE_AUTHOR("Peter Rosin <peda@axentia.se>"); +MODULE_LICENSE("GPL v2"); |