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Subject[PATCH v8 12/12] mux: support simplified bindings for single-user gpio mux
Date
Allow bindings for a GPIO controlled mux to be specified in the
mux consumer node.

Signed-off-by: Peter Rosin <peda@axentia.se>
---
drivers/mux/Kconfig | 5 +----
drivers/mux/mux-core.c | 23 +++++++++++++++++++++--
drivers/mux/mux-gpio.c | 28 +++++++++++++++++++++-------
drivers/mux/mux-gpio.h | 13 +++++++++++++
4 files changed, 56 insertions(+), 13 deletions(-)
create mode 100644 drivers/mux/mux-gpio.h

diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig
index d13fcf98958e..cd161c228537 100644
--- a/drivers/mux/Kconfig
+++ b/drivers/mux/Kconfig
@@ -29,7 +29,7 @@ config MUX_ADG792A
be called mux-adg792a.

config MUX_GPIO
- tristate "GPIO-controlled Multiplexer"
+ bool "GPIO-controlled Multiplexer"
depends on OF && GPIOLIB
help
GPIO-controlled Multiplexer controller.
@@ -39,7 +39,4 @@ config MUX_GPIO
states. The GPIO pins can be connected (by the hardware) to several
multiplexers, which in that case will be operated in parallel.

- To compile the driver as a module, choose M here: the module will
- be called mux-gpio.
-
endif
diff --git a/drivers/mux/mux-core.c b/drivers/mux/mux-core.c
index 16a61253d164..0caafd6f5a77 100644
--- a/drivers/mux/mux-core.c
+++ b/drivers/mux/mux-core.c
@@ -21,6 +21,8 @@
#include <linux/of_platform.h>
#include <linux/slab.h>

+#include "mux-gpio.h"
+
static struct class mux_class = {
.name = "mux",
.owner = THIS_MODULE,
@@ -314,9 +316,26 @@ struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
ret = of_parse_phandle_with_args(np,
"mux-controls", "#mux-control-cells",
index, &args);
+
+#ifdef CONFIG_MUX_GPIO
+ if (ret == -ENOENT && !mux_name) {
+ mux_chip = mux_gpio_alloc(dev);
+ if (!IS_ERR(mux_chip)) {
+ ret = devm_mux_chip_register(dev, mux_chip);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ get_device(&mux_chip->dev);
+ return mux_chip->mux;
+ }
+
+ ret = PTR_ERR(mux_chip);
+ }
+#endif
+
if (ret) {
- dev_err(dev, "%s: failed to get mux-control %s(%i)\n",
- np->full_name, mux_name ?: "", index);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "%s: failed to get mux-control %s(%i)\n",
+ np->full_name, mux_name ?: "", index);
return ERR_PTR(ret);
}

diff --git a/drivers/mux/mux-gpio.c b/drivers/mux/mux-gpio.c
index 48ca4d6b4fc7..2ab8735e3415 100644
--- a/drivers/mux/mux-gpio.c
+++ b/drivers/mux/mux-gpio.c
@@ -18,6 +18,8 @@
#include <linux/platform_device.h>
#include <linux/property.h>

+#include "mux-gpio.h"
+
struct mux_gpio {
struct gpio_descs *gpios;
int *val;
@@ -48,24 +50,21 @@ static const struct of_device_id mux_gpio_dt_ids[] = {
};
MODULE_DEVICE_TABLE(of, mux_gpio_dt_ids);

-static int mux_gpio_probe(struct platform_device *pdev)
+struct mux_chip *mux_gpio_alloc(struct device *dev)
{
- struct device *dev = &pdev->dev;
- struct device_node *np = dev->of_node;
struct mux_chip *mux_chip;
struct mux_gpio *mux_gpio;
int pins;
- u32 idle_state;
int ret;

pins = gpiod_count(dev, "mux");
if (pins < 0)
- return pins;
+ return ERR_PTR(pins);

mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*mux_gpio) +
pins * sizeof(*mux_gpio->val));
if (!mux_chip)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);

mux_gpio = mux_chip_priv(mux_chip);
mux_gpio->val = (int *)(mux_gpio + 1);
@@ -76,11 +75,26 @@ static int mux_gpio_probe(struct platform_device *pdev)
ret = PTR_ERR(mux_gpio->gpios);
if (ret != -EPROBE_DEFER)
dev_err(dev, "failed to get gpios\n");
- return ret;
+ return ERR_PTR(ret);
}
WARN_ON(pins != mux_gpio->gpios->ndescs);
mux_chip->mux->states = 1 << pins;

+ return mux_chip;
+}
+EXPORT_SYMBOL_GPL(mux_gpio_alloc);
+
+static int mux_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mux_chip *mux_chip;
+ u32 idle_state;
+ int ret;
+
+ mux_chip = mux_gpio_alloc(dev);
+ if (IS_ERR(mux_chip))
+ return PTR_ERR(mux_chip);
+
ret = device_property_read_u32(dev, "idle-state", &idle_state);
if (ret >= 0) {
if (idle_state >= mux_chip->mux->states) {
diff --git a/drivers/mux/mux-gpio.h b/drivers/mux/mux-gpio.h
new file mode 100644
index 000000000000..fe3e8d0173aa
--- /dev/null
+++ b/drivers/mux/mux-gpio.h
@@ -0,0 +1,13 @@
+/*
+ * GPIO-controlled multiplexer driver interface
+ *
+ * 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.
+ */
+
+struct mux_chip *mux_gpio_alloc(struct device *dev);
--
2.1.4
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