MLK-16564-01 gpio: imx-rpmsg: add rpmsg virtual gpio driver

Add rpmsg virtual gpio driver support. i.MX7ULP GPIO PTA and PTB resource are managed by M4 core, setup one simple protocol with M4 core based on RPMSG virtual IO to let A core access such GPIOs that is what the driver do. Reviewed-by: Richard Zhu <hongxing.zhu@nxp.com> Reviewed-by: Robin Gong <yibin.gong@nxp.com> Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
anb-rimex · Oct 11, 2017 · 23b0361 · 23b0361
1 parent c27010d
commit 23b0361
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diff --git a/Documentation/devicetree/bindings/gpio/gpio-imx-rpmsg.txt b/Documentation/devicetree/bindings/gpio/gpio-imx-rpmsg.txt
@@ -0,0 +1,38 @@
+Device-Tree bindings for drivers/gpio/gpio-imx-rpmsg.c gpio driver over
+rpmsg. On i.mx7ULP PTA PTB are connected on M4 side, so rpmsg gpio driver
+needed to get/set gpio status from M4 side by rpmsg.
+
+Required properties:
+- compatible : Should be "fsl,imx-rpmsg-gpio".
+- port_idx : Specify the GPIO PORT index, PTA:0, PTB:1.
+- gpio-controller : Mark the device node as a gpio controller.
+- #gpio-cells : Should be two. The first cell is the pin number and
+  the second cell is used to specify the gpio polarity:
+      0 = active high
+      1 = active low
+
+Note: Each GPIO port should have an alias correctly numbered in "aliases"
+node.
+
+Examples:
+
+aliases {
+	gpio4 = &rpmsg_gpio0;
+	gpio5 = &rpmsg_gpio1;
+};
+
+rpmsg_gpio0: rpmsg-gpio0 {
+	compatible = "fsl,imx-rpmsg-gpio";
+	port_idx = <0>;
+	gpio-controller;
+	#gpio-cells = <2>;
+	status = "okay";
+};
+
+rpmsg_gpio1: rpmsg-gpio1 {
+	compatible = "fsl,imx-rpmsg-gpio";
+	port_idx = <1>;
+	gpio-controller;
+	#gpio-cells = <2>;
+	status = "okay";
+};
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
@@ -442,6 +442,12 @@ config GPIO_VF610
 	help
 	  Say yes here to support Vybrid vf610 GPIOs.
 
+config GPIO_IMX_RPMSG
+	bool "NXP i.MX7ULP RPMSG GPIO support"
+	depends on ARCH_MXC && RPMSG && GPIOLIB
+	help
+	  This driver support i.MX7ULP RPMSG virtual GPIOs.
+
 config GPIO_VR41XX
 	tristate "NEC VR4100 series General-purpose I/O Uint support"
 	depends on CPU_VR41XX

diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
@@ -124,6 +124,7 @@ obj-$(CONFIG_GPIO_TZ1090)	+= gpio-tz1090.o
 obj-$(CONFIG_GPIO_TZ1090_PDC)	+= gpio-tz1090-pdc.o
 obj-$(CONFIG_GPIO_UCB1400)	+= gpio-ucb1400.o
 obj-$(CONFIG_GPIO_VF610)	+= gpio-vf610.o
+obj-$(CONFIG_GPIO_IMX_RPMSG)	+= gpio-imx-rpmsg.o
 obj-$(CONFIG_GPIO_VIPERBOARD)	+= gpio-viperboard.o
 obj-$(CONFIG_GPIO_VR41XX)	+= gpio-vr41xx.o
 obj-$(CONFIG_GPIO_VX855)	+= gpio-vx855.o

diff --git a/drivers/gpio/gpio-imx-rpmsg.c b/drivers/gpio/gpio-imx-rpmsg.c
@@ -0,0 +1,322 @@
+/*
+ * Copyright 2017 NXP
+ *
+ * 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; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/imx_rpmsg.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_qos.h>
+#include <linux/rpmsg.h>
+#include <linux/virtio.h>
+
+#define IMX_RPMSG_GPIO_PER_PORT	32
+#define RPMSG_TIMEOUT	1000
+
+enum gpio_input_trigger_type {
+	GPIO_RPMSG_TRI_IGNORE,
+	GPIO_RPMSG_TRI_RISING,
+	GPIO_RPMSG_TRI_FALLING,
+	GPIO_RPMSG_TRI_BOTH_EDGE,
+	GPIO_RPMSG_TRI_LOW_LEVEL,
+	GPIO_RPMSG_TRI_HIGH_LEVEL,
+};
+
+enum gpio_rpmsg_header_type {
+	GPIO_RPMSG_SETUP,
+	GPIO_RPMSG_REPLY,
+	GPIO_RPMSG_NOTIFY,
+};
+
+enum gpio_rpmsg_header_cmd {
+	GPIO_RPMSG_INPUT_INIT,
+	GPIO_RPMSG_OUTPUT_INIT,
+	GPIO_RPMSG_INPUT_GET,
+};
+
+struct gpio_rpmsg_data {
+	struct imx_rpmsg_head header;
+	u8 pin_idx;
+	u8 port_idx;
+	union {
+		u8 event;
+		u8 retcode;
+		u8 value;
+	} out;
+	union {
+		u8 wakeup;
+		u8 value;
+	} in;
+} __packed __aligned(8);
+
+struct imx_rpmsg_gpio_port {
+	struct gpio_chip gc;
+	struct gpio_rpmsg_data msg;
+	int idx;
+};
+
+struct imx_gpio_rpmsg_info {
+	struct rpmsg_device *rpdev;
+	struct gpio_rpmsg_data *notify_msg;
+	struct gpio_rpmsg_data *reply_msg;
+	struct pm_qos_request pm_qos_req;
+	struct completion cmd_complete;
+	struct mutex lock;
+};
+
+static struct imx_gpio_rpmsg_info gpio_rpmsg;
+
+static int gpio_send_message(struct imx_rpmsg_gpio_port *port,
+	struct gpio_rpmsg_data *msg, struct imx_gpio_rpmsg_info *info)
+{
+	int err;
+
+	if (!info->rpdev) {
+		dev_dbg(&info->rpdev->dev,
+			"rpmsg channel not ready, m4 image ready?\n");
+		return -EINVAL;
+	}
+
+	mutex_lock(&info->lock);
+	pm_qos_add_request(&info->pm_qos_req,
+			PM_QOS_CPU_DMA_LATENCY, 0);
+
+	reinit_completion(&info->cmd_complete);
+
+	err = rpmsg_send(info->rpdev->ept, (void *)msg,
+			    sizeof(struct gpio_rpmsg_data));
+
+	if (err) {
+		dev_err(&info->rpdev->dev, "rpmsg_send failed: %d\n", err);
+		goto err_out;
+	}
+
+	err = wait_for_completion_timeout(&info->cmd_complete,
+				msecs_to_jiffies(RPMSG_TIMEOUT));
+	if (!err) {
+		dev_err(&info->rpdev->dev, "rpmsg_send timeout!\n");
+		err = -ETIMEDOUT;
+		goto err_out;
+	}
+
+	if (info->reply_msg->out.retcode != 0) {
+		dev_err(&info->rpdev->dev, "rpmsg not ack %d!\n",
+			info->reply_msg->out.retcode);
+		err = -EINVAL;
+		goto err_out;
+	}
+
+	/* copy the reply message */
+	memcpy(&port->msg, info->reply_msg, sizeof(*info->reply_msg));
+
+	err = 0;
+
+err_out:
+	pm_qos_remove_request(&info->pm_qos_req);
+	mutex_unlock(&info->lock);
+
+	return err;
+}
+
+static int gpio_rpmsg_cb(struct rpmsg_device *rpdev,
+	void *data, int len, void *priv, u32 src)
+{
+	struct gpio_rpmsg_data *msg = (struct gpio_rpmsg_data *)data;
+
+	if (msg->header.type == GPIO_RPMSG_REPLY) {
+		gpio_rpmsg.reply_msg = msg;
+		complete(&gpio_rpmsg.cmd_complete);
+	} else if (msg->header.type == GPIO_RPMSG_NOTIFY) {
+		gpio_rpmsg.notify_msg = msg;
+		/* TBD for interrupt handler */
+	} else
+		dev_err(&gpio_rpmsg.rpdev->dev, "wrong command type!\n");
+
+	return 0;
+}
+
+static int imx_rpmsg_gpio_get(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct imx_rpmsg_gpio_port *port = gpiochip_get_data(gc);
+	struct gpio_rpmsg_data msg;
+	int ret;
+
+	memset(&msg, 0, sizeof(struct gpio_rpmsg_data));
+	msg.header.cate = IMX_RPMSG_GPIO;
+	msg.header.major = IMX_RMPSG_MAJOR;
+	msg.header.minor = IMX_RMPSG_MINOR;
+	msg.header.type = GPIO_RPMSG_SETUP;
+	msg.header.cmd = GPIO_RPMSG_INPUT_GET;
+	msg.pin_idx = gpio;
+	msg.port_idx = port->idx;
+
+	ret = gpio_send_message(port, &msg, &gpio_rpmsg);
+	if (!ret)
+		return !!port->msg.in.value;
+
+	return ret;
+}
+
+static int imx_rpmsg_gpio_direction_input(struct gpio_chip *gc,
+					  unsigned int gpio)
+{
+	struct imx_rpmsg_gpio_port *port = gpiochip_get_data(gc);
+	struct gpio_rpmsg_data msg;
+
+	memset(&msg, 0, sizeof(struct gpio_rpmsg_data));
+	msg.header.cate = IMX_RPMSG_GPIO;
+	msg.header.major = IMX_RMPSG_MAJOR;
+	msg.header.minor = IMX_RMPSG_MINOR;
+	msg.header.type = GPIO_RPMSG_SETUP;
+	msg.header.cmd = GPIO_RPMSG_INPUT_INIT;
+	msg.pin_idx = gpio;
+	msg.port_idx = port->idx;
+
+	/* TBD: get event trigger and wakeup from GPIO descriptor */
+	msg.out.event = GPIO_RPMSG_TRI_IGNORE;
+	msg.in.wakeup = 0;
+
+	return gpio_send_message(port, &msg, &gpio_rpmsg);
+}
+
+static inline void imx_rpmsg_gpio_direction_output_init(struct gpio_chip *gc,
+		unsigned int gpio, int val, struct gpio_rpmsg_data *msg)
+{
+	struct imx_rpmsg_gpio_port *port = gpiochip_get_data(gc);
+
+	msg->header.cate = IMX_RPMSG_GPIO;
+	msg->header.major = IMX_RMPSG_MAJOR;
+	msg->header.minor = IMX_RMPSG_MINOR;
+	msg->header.type = GPIO_RPMSG_SETUP;
+	msg->header.cmd = GPIO_RPMSG_OUTPUT_INIT;
+	msg->pin_idx = gpio;
+	msg->port_idx = port->idx;
+	msg->out.value = val;
+}
+
+static void imx_rpmsg_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+	struct imx_rpmsg_gpio_port *port = gpiochip_get_data(gc);
+	struct gpio_rpmsg_data msg;
+
+	memset(&msg, 0, sizeof(struct gpio_rpmsg_data));
+	imx_rpmsg_gpio_direction_output_init(gc, gpio, val, &msg);
+	gpio_send_message(port, &msg, &gpio_rpmsg);
+}
+
+static int imx_rpmsg_gpio_direction_output(struct gpio_chip *gc,
+					unsigned int gpio, int val)
+{
+	struct imx_rpmsg_gpio_port *port = gpiochip_get_data(gc);
+	struct gpio_rpmsg_data msg;
+
+	memset(&msg, 0, sizeof(struct gpio_rpmsg_data));
+	imx_rpmsg_gpio_direction_output_init(gc, gpio, val, &msg);
+	return gpio_send_message(port, &msg, &gpio_rpmsg);
+}
+
+static int gpio_rpmsg_probe(struct rpmsg_device *rpdev)
+{
+	gpio_rpmsg.rpdev = rpdev;
+	dev_info(&rpdev->dev, "new channel: 0x%x -> 0x%x!\n",
+			rpdev->src, rpdev->dst);
+
+	init_completion(&gpio_rpmsg.cmd_complete);
+	mutex_init(&gpio_rpmsg.lock);
+
+	return 0;
+}
+
+static struct rpmsg_device_id gpio_rpmsg_id_table[] = {
+	{ .name = "rpmsg-io-channel" },
+	{},
+};
+
+static struct rpmsg_driver gpio_rpmsg_driver = {
+	.drv.name	= "gpio_rpmsg",
+	.drv.owner	= THIS_MODULE,
+	.id_table	= gpio_rpmsg_id_table,
+	.probe		= gpio_rpmsg_probe,
+	.callback	= gpio_rpmsg_cb,
+};
+
+static int imx_rpmsg_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct imx_rpmsg_gpio_port *port;
+	struct gpio_chip *gc;
+	int ret;
+
+	port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+
+	ret = of_property_read_u32(np, "port_idx", &port->idx);
+	if (ret)
+		return ret;
+
+	gc = &port->gc;
+	gc->of_node = np;
+	gc->parent = dev;
+	gc->label = "imx-rpmsg-gpio";
+	gc->ngpio = IMX_RPMSG_GPIO_PER_PORT;
+	gc->base = of_alias_get_id(np, "gpio") * IMX_RPMSG_GPIO_PER_PORT;
+
+	gc->direction_input = imx_rpmsg_gpio_direction_input;
+	gc->direction_output = imx_rpmsg_gpio_direction_output;
+	gc->get = imx_rpmsg_gpio_get;
+	gc->set = imx_rpmsg_gpio_set;
+
+	platform_set_drvdata(pdev, port);
+
+	ret = devm_gpiochip_add_data(dev, gc, port);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static const struct of_device_id imx_rpmsg_gpio_dt_ids[] = {
+	{ .compatible = "fsl,imx-rpmsg-gpio" },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver imx_rpmsg_gpio_driver = {
+	.driver	= {
+		.name = "gpio-imx-rpmsg",
+		.of_match_table = imx_rpmsg_gpio_dt_ids,
+	},
+	.probe = imx_rpmsg_gpio_probe,
+};
+
+static int __init gpio_imx_rpmsg_init(void)
+{
+	int ret;
+
+	ret = register_rpmsg_driver(&gpio_rpmsg_driver);
+	if (ret)
+		return ret;
+
+	return platform_driver_register(&imx_rpmsg_gpio_driver);
+}
+device_initcall(gpio_imx_rpmsg_init);
+
+MODULE_AUTHOR("NXP Semiconductor");
+MODULE_DESCRIPTION("NXP i.MX7ULP rpmsg gpio driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/rpmsg/imx_rpmsg.c b/drivers/rpmsg/imx_rpmsg.c
@@ -52,7 +52,7 @@ struct imx_rpmsg_vproc {
 	char *rproc_name;
 	struct mutex lock;
 	int vdev_nums;
-#define MAX_VDEV_NUMS	6
+#define MAX_VDEV_NUMS	7
 	struct imx_virdev ivdev[MAX_VDEV_NUMS];
 };
 

diff --git a/include/linux/imx_rpmsg.h b/include/linux/imx_rpmsg.h
@@ -27,6 +27,7 @@
 #define IMX_RPMSG_PMIC		2
 #define IMX_RPMSG_AUDIO		3
 #define IMX_RPMSG_KEY		4
+#define IMX_RPMSG_GPIO		5
 /* rpmsg version */
 #define IMX_RMPSG_MAJOR		1
 #define IMX_RMPSG_MINOR		0