From: Peter Rosin <peda@axentia.se>
To: <linux-kernel@vger.kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Rosin <peda@axentia.se>, Wolfram Sang <wsa@the-dreams.de>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Jonathan Cameron <jic23@kernel.org>,
Hartmut Knaack <knaack.h@gmx.de>,
Lars-Peter Clausen <lars@metafoo.de>,
Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
Jonathan Corbet <corbet@lwn.net>, <linux-i2c@vger.kernel.org>,
<devicetree@vger.kernel.org>, <linux-iio@vger.kernel.org>,
<linux-doc@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Colin Ian King <colin.king@canonical.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Philipp Zabel <p.zabel@pengutronix.de>, <kernel@pengutronix.de>
Subject: [PATCH v13 08/10] i2c: i2c-mux-gpmux: new driver
Date: Thu, 13 Apr 2017 18:43:12 +0200 [thread overview]
Message-ID: <1492101794-13444-9-git-send-email-peda@axentia.se> (raw)
In-Reply-To: <1492101794-13444-1-git-send-email-peda@axentia.se>
This is a general purpose i2c mux that uses a multiplexer controlled by
the multiplexer subsystem to do the muxing.
The user can select if the mux is to be mux-locked and parent-locked
as described in Documentation/i2c/i2c-topology.
Acked-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Peter Rosin <peda@axentia.se>
---
drivers/i2c/muxes/Kconfig | 13 +++
drivers/i2c/muxes/Makefile | 1 +
drivers/i2c/muxes/i2c-mux-gpmux.c | 173 ++++++++++++++++++++++++++++++++++++++
3 files changed, 187 insertions(+)
create mode 100644 drivers/i2c/muxes/i2c-mux-gpmux.c
diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig
index 10b3d17ae3ea..11115fb34f24 100644
--- a/drivers/i2c/muxes/Kconfig
+++ b/drivers/i2c/muxes/Kconfig
@@ -30,6 +30,19 @@ config I2C_MUX_GPIO
This driver can also be built as a module. If so, the module
will be called i2c-mux-gpio.
+config I2C_MUX_GPMUX
+ tristate "General Purpose I2C multiplexer"
+ select MULTIPLEXER
+ depends on OF
+ help
+ If you say yes to this option, support will be included for a
+ general purpose I2C multiplexer. This driver provides access to
+ I2C busses connected through a MUX, which in turn is controlled
+ by a MUX-controller from the MUX subsystem.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-mux-gpmux.
+
config I2C_MUX_PCA9541
tristate "NXP PCA9541 I2C Master Selector"
help
diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile
index 9948fa45037f..af43c6c3e861 100644
--- a/drivers/i2c/muxes/Makefile
+++ b/drivers/i2c/muxes/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_I2C_ARB_GPIO_CHALLENGE) += i2c-arb-gpio-challenge.o
obj-$(CONFIG_I2C_DEMUX_PINCTRL) += i2c-demux-pinctrl.o
obj-$(CONFIG_I2C_MUX_GPIO) += i2c-mux-gpio.o
+obj-$(CONFIG_I2C_MUX_GPMUX) += i2c-mux-gpmux.o
obj-$(CONFIG_I2C_MUX_MLXCPLD) += i2c-mux-mlxcpld.o
obj-$(CONFIG_I2C_MUX_PCA9541) += i2c-mux-pca9541.o
obj-$(CONFIG_I2C_MUX_PCA954x) += i2c-mux-pca954x.o
diff --git a/drivers/i2c/muxes/i2c-mux-gpmux.c b/drivers/i2c/muxes/i2c-mux-gpmux.c
new file mode 100644
index 000000000000..fb23b2278462
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-gpmux.c
@@ -0,0 +1,173 @@
+/*
+ * General Purpose I2C multiplexer
+ *
+ * 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/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/module.h>
+#include <linux/mux.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+
+struct mux {
+ struct mux_control *control;
+
+ bool do_not_deselect;
+};
+
+static int i2c_mux_select(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct mux *mux = i2c_mux_priv(muxc);
+ int ret;
+
+ ret = mux_control_select(mux->control, chan);
+ mux->do_not_deselect = ret < 0;
+
+ return ret;
+}
+
+static int i2c_mux_deselect(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct mux *mux = i2c_mux_priv(muxc);
+
+ if (mux->do_not_deselect)
+ return 0;
+
+ return mux_control_deselect(mux->control);
+}
+
+static struct i2c_adapter *mux_parent_adapter(struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ struct device_node *parent_np;
+ struct i2c_adapter *parent;
+
+ parent_np = of_parse_phandle(np, "i2c-parent", 0);
+ if (!parent_np) {
+ dev_err(dev, "Cannot parse i2c-parent\n");
+ return ERR_PTR(-ENODEV);
+ }
+ parent = of_find_i2c_adapter_by_node(parent_np);
+ of_node_put(parent_np);
+ if (!parent)
+ return ERR_PTR(-EPROBE_DEFER);
+
+ return parent;
+}
+
+static const struct of_device_id i2c_mux_of_match[] = {
+ { .compatible = "i2c-mux", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, i2c_mux_of_match);
+
+static int i2c_mux_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct device_node *child;
+ struct i2c_mux_core *muxc;
+ struct mux *mux;
+ struct i2c_adapter *parent;
+ int children;
+ int ret;
+
+ if (!np)
+ return -ENODEV;
+
+ mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ return -ENOMEM;
+
+ mux->control = devm_mux_control_get(dev, NULL);
+ if (IS_ERR(mux->control)) {
+ if (PTR_ERR(mux->control) != -EPROBE_DEFER)
+ dev_err(dev, "failed to get control-mux\n");
+ return PTR_ERR(mux->control);
+ }
+
+ parent = mux_parent_adapter(dev);
+ if (IS_ERR(parent)) {
+ if (PTR_ERR(parent) != -EPROBE_DEFER)
+ dev_err(dev, "failed to get i2c-parent adapter\n");
+ return PTR_ERR(parent);
+ }
+
+ children = of_get_child_count(np);
+
+ muxc = i2c_mux_alloc(parent, dev, children, 0, 0,
+ i2c_mux_select, i2c_mux_deselect);
+ if (!muxc) {
+ ret = -ENOMEM;
+ goto err_parent;
+ }
+ muxc->priv = mux;
+
+ platform_set_drvdata(pdev, muxc);
+
+ muxc->mux_locked = of_property_read_bool(np, "mux-locked");
+
+ for_each_child_of_node(np, child) {
+ u32 chan;
+
+ ret = of_property_read_u32(child, "reg", &chan);
+ if (ret < 0) {
+ dev_err(dev, "no reg property for node '%s'\n",
+ child->name);
+ goto err_children;
+ }
+
+ if (chan >= mux->control->states) {
+ dev_err(dev, "invalid reg %u\n", chan);
+ ret = -EINVAL;
+ goto err_children;
+ }
+
+ ret = i2c_mux_add_adapter(muxc, 0, chan, 0);
+ if (ret)
+ goto err_children;
+ }
+
+ dev_info(dev, "%d-port mux on %s adapter\n", children, parent->name);
+
+ return 0;
+
+err_children:
+ i2c_mux_del_adapters(muxc);
+err_parent:
+ i2c_put_adapter(parent);
+
+ return ret;
+}
+
+static int i2c_mux_remove(struct platform_device *pdev)
+{
+ struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
+
+ i2c_mux_del_adapters(muxc);
+ i2c_put_adapter(muxc->parent);
+
+ return 0;
+}
+
+static struct platform_driver i2c_mux_driver = {
+ .probe = i2c_mux_probe,
+ .remove = i2c_mux_remove,
+ .driver = {
+ .name = "i2c-mux-gpmux",
+ .of_match_table = i2c_mux_of_match,
+ },
+};
+module_platform_driver(i2c_mux_driver);
+
+MODULE_DESCRIPTION("General Purpose I2C multiplexer driver");
+MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
+MODULE_LICENSE("GPL v2");
--
2.1.4
next prev parent reply other threads:[~2017-04-13 16:43 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-13 16:43 [PATCH v13 00/10] mux controller abstraction and iio/i2c muxes Peter Rosin
2017-04-13 16:43 ` [PATCH v13 01/10] devres: trivial whitespace fix Peter Rosin
2017-04-13 16:43 ` [PATCH v13 02/10] dt-bindings: document devicetree bindings for mux-controllers and gpio-mux Peter Rosin
2017-04-18 10:06 ` Philipp Zabel
2017-04-18 13:36 ` Peter Rosin
2017-04-19 9:17 ` Philipp Zabel
2017-04-19 10:41 ` Peter Rosin
2017-04-19 11:05 ` Philipp Zabel
2017-04-19 11:23 ` Peter Rosin
2017-04-19 16:34 ` Philipp Zabel
2017-04-13 16:43 ` [PATCH v13 03/10] mux: minimal mux subsystem and gpio-based mux controller Peter Rosin
2017-04-18 8:34 ` Philipp Zabel
2017-04-18 8:51 ` Greg Kroah-Hartman
2017-04-18 10:59 ` Peter Rosin
2017-04-18 11:44 ` Greg Kroah-Hartman
2017-04-18 21:53 ` Peter Rosin
2017-04-19 2:23 ` Joe Perches
2017-04-20 21:53 ` Peter Rosin
2017-04-21 23:28 ` Peter Rosin
2017-05-05 13:19 ` Peter Rosin
2017-04-19 9:06 ` Philipp Zabel
2017-04-19 12:00 ` Peter Rosin
2017-04-19 13:49 ` Philipp Zabel
2017-04-19 21:04 ` Peter Rosin
2017-04-21 14:18 ` Philipp Zabel
2017-04-21 15:08 ` Peter Rosin
2017-04-21 14:23 ` Philipp Zabel
2017-04-21 14:32 ` Peter Rosin
2017-04-21 14:41 ` Philipp Zabel
2017-04-21 14:55 ` Peter Rosin
2017-04-21 15:19 ` Philipp Zabel
2017-04-13 16:43 ` [PATCH v13 04/10] iio: inkern: api for manipulating ext_info of iio channels Peter Rosin
2017-04-13 16:43 ` [PATCH v13 05/10] dt-bindings: iio: io-channel-mux: document io-channel-mux bindings Peter Rosin
2017-04-13 16:43 ` [PATCH v13 06/10] iio: multiplexer: new iio category and iio-mux driver Peter Rosin
2017-04-13 16:43 ` [PATCH v13 07/10] dt-bindings: i2c: i2c-mux: document general purpose i2c-mux bindings Peter Rosin
2017-04-13 16:43 ` Peter Rosin [this message]
2017-04-13 16:43 ` [PATCH v13 09/10] dt-bindings: mux-adg792a: document devicetree bindings for ADG792A/G mux Peter Rosin
2017-04-13 16:43 ` [PATCH v13 10/10] mux: adg792a: add mux controller driver for ADG792A/G Peter Rosin
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