[PATCH v5 02/10] Input: synaptics-rmi4: Add I2C transport driver

* [PATCH v5 02/10] Input: synaptics-rmi4: Add I2C transport driver
@ 2016-02-10 22:23 ` Andrew Duggan
  0 siblings, 0 replies; 2+ messages in thread
From: Andrew Duggan @ 2016-02-10 22:23 UTC (permalink / raw)
  To: linux-input, linux-kernel
  Cc: Andrew Duggan, Dmitry Torokhov, Linus Walleij, Jiri Kosina,
	Benjamin Tissoires, Christopher Heiny, Stephen Chandler Paul,
	Vincent Huang, Chris Healy, Andrey Gusakov

Add the transport driver for devices using RMI4 over I2C.

Signed-off-by: Andrew Duggan <aduggan@synaptics.com>
Signed-off-by: Christopher Heiny <cheiny@synaptics.com>
---
 drivers/input/rmi4/Kconfig   |   9 +
 drivers/input/rmi4/Makefile  |   3 +
 drivers/input/rmi4/rmi_i2c.c | 387 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 399 insertions(+)
 create mode 100644 drivers/input/rmi4/rmi_i2c.c

diff --git a/drivers/input/rmi4/Kconfig b/drivers/input/rmi4/Kconfig
index 5ea60e3..cc3f7c5 100644
--- a/drivers/input/rmi4/Kconfig
+++ b/drivers/input/rmi4/Kconfig
@@ -8,3 +8,12 @@ config RMI4_CORE
 	  required for all RMI4 device support.
 
 	  If unsure, say Y.
+
+config RMI4_I2C
+	tristate "RMI4 I2C Support"
+	depends on RMI4_CORE && I2C
+	help
+	  Say Y here if you want to support RMI4 devices connected to an I2C
+	  bus.
+
+	  If unsure, say Y.
diff --git a/drivers/input/rmi4/Makefile b/drivers/input/rmi4/Makefile
index 12f2197..5539494 100644
--- a/drivers/input/rmi4/Makefile
+++ b/drivers/input/rmi4/Makefile
@@ -1,2 +1,5 @@
 obj-$(CONFIG_RMI4_CORE) += rmi_core.o
 rmi_core-y := rmi_bus.o rmi_driver.o rmi_f01.o
+
+# Transports
+obj-$(CONFIG_RMI4_I2C) += rmi_i2c.o
diff --git a/drivers/input/rmi4/rmi_i2c.c b/drivers/input/rmi4/rmi_i2c.c
new file mode 100644
index 0000000..f93742b
--- /dev/null
+++ b/drivers/input/rmi4/rmi_i2c.c
@@ -0,0 +1,387 @@
+/*
+ * Copyright (c) 2011-2016 Synaptics Incorporated
+ * Copyright (c) 2011 Unixphere
+ *
+ * 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/rmi.h>
+#include <linux/irq.h>
+#include "rmi_driver.h"
+
+#define BUFFER_SIZE_INCREMENT 32
+
+/**
+ * struct rmi_i2c_xport - stores information for i2c communication
+ *
+ * @xport: The transport interface structure
+ *
+ * @page_mutex: Locks current page to avoid changing pages in unexpected ways.
+ * @page: Keeps track of the current virtual page
+ *
+ * @tx_buf: Buffer used for transmitting data to the sensor over i2c.
+ * @tx_buf_size: Size of the buffer
+ */
+struct rmi_i2c_xport {
+	struct rmi_transport_dev xport;
+	struct i2c_client *client;
+
+	struct mutex page_mutex;
+	int page;
+
+	int irq;
+
+	u8 *tx_buf;
+	size_t tx_buf_size;
+};
+
+#define RMI_PAGE_SELECT_REGISTER 0xff
+#define RMI_I2C_PAGE(addr) (((addr) >> 8) & 0xff)
+
+/*
+ * rmi_set_page - Set RMI page
+ * @xport: The pointer to the rmi_transport_dev struct
+ * @page: The new page address.
+ *
+ * RMI devices have 16-bit addressing, but some of the transport
+ * implementations (like SMBus) only have 8-bit addressing. So RMI implements
+ * a page address at 0xff of every page so we can reliable page addresses
+ * every 256 registers.
+ *
+ * The page_mutex lock must be held when this function is entered.
+ *
+ * Returns zero on success, non-zero on failure.
+ */
+static int rmi_set_page(struct rmi_i2c_xport *rmi_i2c, u8 page)
+{
+	struct i2c_client *client = rmi_i2c->client;
+	u8 txbuf[2] = {RMI_PAGE_SELECT_REGISTER, page};
+	int retval;
+
+	retval = i2c_master_send(client, txbuf, sizeof(txbuf));
+	if (retval != sizeof(txbuf)) {
+		dev_err(&client->dev,
+			"%s: set page failed: %d.", __func__, retval);
+		return (retval < 0) ? retval : -EIO;
+	}
+
+	rmi_i2c->page = page;
+	return 0;
+}
+
+static int rmi_i2c_write_block(struct rmi_transport_dev *xport, u16 addr,
+			       const void *buf, size_t len)
+{
+	struct rmi_i2c_xport *rmi_i2c =
+		container_of(xport, struct rmi_i2c_xport, xport);
+	struct i2c_client *client = rmi_i2c->client;
+	size_t tx_size = len + 1;
+	int retval;
+
+	mutex_lock(&rmi_i2c->page_mutex);
+
+	if (!rmi_i2c->tx_buf || rmi_i2c->tx_buf_size < tx_size) {
+		if (rmi_i2c->tx_buf)
+			devm_kfree(&client->dev, rmi_i2c->tx_buf);
+		rmi_i2c->tx_buf_size = tx_size + BUFFER_SIZE_INCREMENT;
+		rmi_i2c->tx_buf = devm_kzalloc(&client->dev,
+					       rmi_i2c->tx_buf_size,
+					       GFP_KERNEL);
+		if (!rmi_i2c->tx_buf) {
+			rmi_i2c->tx_buf_size = 0;
+			retval = -ENOMEM;
+			goto exit;
+		}
+	}
+
+	rmi_i2c->tx_buf[0] = addr & 0xff;
+	memcpy(rmi_i2c->tx_buf + 1, buf, len);
+
+	if (RMI_I2C_PAGE(addr) != rmi_i2c->page) {
+		retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr));
+		if (retval)
+			goto exit;
+	}
+
+	retval = i2c_master_send(client, rmi_i2c->tx_buf, tx_size);
+	if (retval == tx_size)
+		retval = 0;
+	else if (retval >= 0)
+		retval = -EIO;
+
+exit:
+	rmi_dbg(RMI_DEBUG_XPORT, &client->dev,
+		"write %zd bytes at %#06x: %d (%*ph)\n",
+		len, addr, retval, (int)len, buf);
+
+	mutex_unlock(&rmi_i2c->page_mutex);
+	return retval;
+}
+
+static int rmi_i2c_read_block(struct rmi_transport_dev *xport, u16 addr,
+			      void *buf, size_t len)
+{
+	struct rmi_i2c_xport *rmi_i2c =
+		container_of(xport, struct rmi_i2c_xport, xport);
+	struct i2c_client *client = rmi_i2c->client;
+	u8 addr_offset = addr & 0xff;
+	int retval;
+	struct i2c_msg msgs[] = {
+		{
+			.addr	= client->addr,
+			.len	= sizeof(addr_offset),
+			.buf	= &addr_offset,
+		},
+		{
+			.addr	= client->addr,
+			.flags	= I2C_M_RD,
+			.len	= len,
+			.buf	= buf,
+		},
+	};
+
+	mutex_lock(&rmi_i2c->page_mutex);
+
+	if (RMI_I2C_PAGE(addr) != rmi_i2c->page) {
+		retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr));
+		if (retval)
+			goto exit;
+	}
+
+	retval = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	if (retval == ARRAY_SIZE(msgs))
+		retval = 0; /* success */
+	else if (retval >= 0)
+		retval = -EIO;
+
+exit:
+	rmi_dbg(RMI_DEBUG_XPORT, &client->dev,
+		"read %zd bytes at %#06x: %d (%*ph)\n",
+		len, addr, retval, (int)len, buf);
+
+	mutex_unlock(&rmi_i2c->page_mutex);
+	return retval;
+}
+
+static const struct rmi_transport_ops rmi_i2c_ops = {
+	.write_block	= rmi_i2c_write_block,
+	.read_block	= rmi_i2c_read_block,
+};
+
+static irqreturn_t rmi_i2c_irq(int irq, void *dev_id)
+{
+	struct rmi_i2c_xport *rmi_i2c = dev_id;
+	struct rmi_device *rmi_dev = rmi_i2c->xport.rmi_dev;
+	int ret;
+
+	ret = rmi_process_interrupt_requests(rmi_dev);
+	if (ret)
+		rmi_dbg(RMI_DEBUG_XPORT, &rmi_dev->dev,
+			"Failed to process interrupt request: %d\n", ret);
+
+	return IRQ_HANDLED;
+}
+
+static int rmi_i2c_init_irq(struct i2c_client *client)
+{
+	struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
+	int irq_flags = irqd_get_trigger_type(irq_get_irq_data(rmi_i2c->irq));
+	int ret;
+
+	if (!irq_flags)
+		irq_flags = IRQF_TRIGGER_LOW;
+
+	ret = devm_request_threaded_irq(&client->dev, rmi_i2c->irq, NULL,
+			rmi_i2c_irq, irq_flags | IRQF_ONESHOT, client->name,
+			rmi_i2c);
+	if (ret < 0) {
+		dev_warn(&client->dev, "Failed to register interrupt %d\n",
+			rmi_i2c->irq);
+
+		return ret;
+	}
+
+	return 0;
+}
+
+static int rmi_i2c_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct rmi_device_platform_data *pdata;
+	struct rmi_device_platform_data *client_pdata =
+					dev_get_platdata(&client->dev);
+	struct rmi_i2c_xport *rmi_i2c;
+	int retval;
+
+	rmi_i2c = devm_kzalloc(&client->dev, sizeof(struct rmi_i2c_xport),
+				GFP_KERNEL);
+	if (!rmi_i2c)
+		return -ENOMEM;
+
+	pdata = &rmi_i2c->xport.pdata;
+
+	if (client_pdata)
+		*pdata = *client_pdata;
+
+	if (client->irq > 0)
+		rmi_i2c->irq = client->irq;
+
+	rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Probing %s.\n",
+			dev_name(&client->dev));
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		dev_err(&client->dev,
+			"adapter does not support required functionality.\n");
+		return -ENODEV;
+	}
+
+	rmi_i2c->client = client;
+	mutex_init(&rmi_i2c->page_mutex);
+
+	rmi_i2c->xport.dev = &client->dev;
+	rmi_i2c->xport.proto_name = "i2c";
+	rmi_i2c->xport.ops = &rmi_i2c_ops;
+
+	i2c_set_clientdata(client, rmi_i2c);
+
+	/*
+	 * Setting the page to zero will (a) make sure the PSR is in a
+	 * known state, and (b) make sure we can talk to the device.
+	 */
+	retval = rmi_set_page(rmi_i2c, 0);
+	if (retval) {
+		dev_err(&client->dev, "Failed to set page select to 0.\n");
+		return retval;
+	}
+
+	retval = rmi_register_transport_device(&rmi_i2c->xport);
+	if (retval) {
+		dev_err(&client->dev, "Failed to register transport driver at 0x%.2X.\n",
+			client->addr);
+		return retval;
+	}
+
+	retval = rmi_i2c_init_irq(client);
+	if (retval < 0)
+		return retval;
+
+	dev_info(&client->dev, "registered rmi i2c driver at %#04x.\n",
+			client->addr);
+	return 0;
+}
+
+static int rmi_i2c_remove(struct i2c_client *client)
+{
+	struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
+
+	rmi_unregister_transport_device(&rmi_i2c->xport);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int rmi_i2c_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
+	int ret;
+
+	ret = rmi_driver_suspend(rmi_i2c->xport.rmi_dev);
+	if (ret)
+		dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+	disable_irq(rmi_i2c->irq);
+	if (device_may_wakeup(&client->dev)) {
+		ret = enable_irq_wake(rmi_i2c->irq);
+		if (!ret)
+			dev_warn(dev, "Failed to enable irq for wake: %d\n",
+				ret);
+	}
+	return ret;
+}
+
+static int rmi_i2c_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
+	int ret;
+
+	enable_irq(rmi_i2c->irq);
+	if (device_may_wakeup(&client->dev)) {
+		ret = disable_irq_wake(rmi_i2c->irq);
+		if (!ret)
+			dev_warn(dev, "Failed to disable irq for wake: %d\n",
+				ret);
+	}
+
+	ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev);
+	if (ret)
+		dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+	return ret;
+}
+#endif
+
+#ifdef CONFIG_PM
+static int rmi_i2c_runtime_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
+	int ret;
+
+	ret = rmi_driver_suspend(rmi_i2c->xport.rmi_dev);
+	if (ret)
+		dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+	disable_irq(rmi_i2c->irq);
+
+	return 0;
+}
+
+static int rmi_i2c_runtime_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
+	int ret;
+
+	enable_irq(rmi_i2c->irq);
+
+	ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev);
+	if (ret)
+		dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops rmi_i2c_pm = {
+	SET_SYSTEM_SLEEP_PM_OPS(rmi_i2c_suspend, rmi_i2c_resume)
+	SET_RUNTIME_PM_OPS(rmi_i2c_runtime_suspend, rmi_i2c_runtime_resume,
+			   NULL)
+};
+
+static const struct i2c_device_id rmi_id[] = {
+	{ "rmi4_i2c", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, rmi_id);
+
+static struct i2c_driver rmi_i2c_driver = {
+	.driver = {
+		.name	= "rmi4_i2c",
+		.pm	= &rmi_i2c_pm,
+	},
+	.id_table	= rmi_id,
+	.probe		= rmi_i2c_probe,
+	.remove		= rmi_i2c_remove,
+};
+
+module_i2c_driver(rmi_i2c_driver);
+
+MODULE_AUTHOR("Christopher Heiny <cheiny@synaptics.com>");
+MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>");
+MODULE_DESCRIPTION("RMI I2C driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(RMI_DRIVER_VERSION);
-- 
2.5.0

^ permalink raw reply related	[flat|nested] 2+ messages in thread