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authorLinus Torvalds <torvalds@linux-foundation.org>2017-09-05 11:08:17 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-05 11:08:17 -0700
commitbafb0762cb6a906eb4105cccfb3bcd90be7f40d2 (patch)
tree14ecb87c33bcf909e5b95c27cd694ded4ac1478c /drivers/mux/gpio.c
parent44b1671fae88ce95b8c7b53acbc6ba71ca67db00 (diff)
parent3a6430ce462172caac7c73f4afd550ab0f105737 (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.c114
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");