[PATCH 01/11] Input: synaptics-rmi4 - add SMBus support

From: Benjamin Tissoires
Date: Thu Aug 18 2016 - 05:27:36 EST

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Code obtained from https://raw.githubusercontent.com/mightybigcar/synaptics-rmi4/jf/drivers/input/rmi4/rmi_smbus.c
and updated to match upstream. And fixed to make it work.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Signed-off-by: Andrew Duggan <aduggan@xxxxxxxxxxxxx>

---

Changes in this series:
- rely on PM functions for resume handling

Changes from the Host Notify series:
new in v5

no changes in v6

changes in v7:
- fixed typos as per Andrew's requests
- changed module author from Allie to Andrew as per Andrew's request
- add suspend/resume callbacks to match upstream rmi4 behavior

no changes in v8
---
drivers/input/rmi4/Kconfig | 12 ++
drivers/input/rmi4/Makefile | 1 +
drivers/input/rmi4/rmi_bus.h | 12 ++
drivers/input/rmi4/rmi_smbus.c | 449 +++++++++++++++++++++++++++++++++++++++++
4 files changed, 474 insertions(+)
create mode 100644 drivers/input/rmi4/rmi_smbus.c

diff --git a/drivers/input/rmi4/Kconfig b/drivers/input/rmi4/Kconfig
index f73df24..86a180b 100644
--- a/drivers/input/rmi4/Kconfig
+++ b/drivers/input/rmi4/Kconfig
@@ -27,6 +27,18 @@ config RMI4_SPI

If unsure, say N.

+config RMI4_SMB
+ tristate "RMI4 SMB Support"
+ depends on RMI4_CORE && I2C
+ help
+ Say Y here if you want to support RMI4 devices connected to an SMB
+ bus.
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here: the module will be
+ called rmi_smbus.
+
config RMI4_2D_SENSOR
bool
depends on RMI4_CORE
diff --git a/drivers/input/rmi4/Makefile b/drivers/input/rmi4/Makefile
index 95c00a7..3c8ebf2 100644
--- a/drivers/input/rmi4/Makefile
+++ b/drivers/input/rmi4/Makefile
@@ -11,3 +11,4 @@ rmi_core-$(CONFIG_RMI4_F30) += rmi_f30.o
# Transports
obj-$(CONFIG_RMI4_I2C) += rmi_i2c.o
obj-$(CONFIG_RMI4_SPI) += rmi_spi.o
+obj-$(CONFIG_RMI4_SMB) += rmi_smbus.o
diff --git a/drivers/input/rmi4/rmi_bus.h b/drivers/input/rmi4/rmi_bus.h
index 8995798..b7625a9 100644
--- a/drivers/input/rmi4/rmi_bus.h
+++ b/drivers/input/rmi4/rmi_bus.h
@@ -105,6 +105,18 @@ rmi_get_platform_data(struct rmi_device *d)
bool rmi_is_physical_device(struct device *dev);

/**
+ * rmi_reset - reset a RMI4 device
+ * @d: Pointer to an RMI device
+ *
+ * Calls for a reset of each function implemented by a specific device.
+ * Returns 0 on success or a negative error code.
+ */
+static inline int rmi_reset(struct rmi_device *d)
+{
+ return d->driver->reset_handler(d);
+}
+
+/**
* rmi_read - read a single byte
* @d: Pointer to an RMI device
* @addr: The address to read from
diff --git a/drivers/input/rmi4/rmi_smbus.c b/drivers/input/rmi4/rmi_smbus.c
new file mode 100644
index 0000000..4d6f228
--- /dev/null
+++ b/drivers/input/rmi4/rmi_smbus.c
@@ -0,0 +1,449 @@
+/*
+ * Copyright (c) 2015 - 2016 Red Hat, Inc
+ * Copyright (c) 2011, 2012 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/kernel.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kconfig.h>
+#include <linux/lockdep.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/rmi.h>
+#include <linux/slab.h>
+#include "rmi_driver.h"
+
+#define SMB_PROTOCOL_VERSION_ADDRESS 0xfd
+#define SMB_MAX_COUNT 32
+#define RMI_SMB2_MAP_SIZE 8 /* 8 entry of 4 bytes each */
+#define RMI_SMB2_MAP_FLAGS_WE 0x01
+
+struct mapping_table_entry {
+ __le16 rmiaddr;
+ u8 readcount;
+ u8 flags;
+};
+
+struct rmi_smb_xport {
+ struct rmi_transport_dev xport;
+ struct i2c_client *client;
+
+ struct mutex page_mutex;
+ int page;
+ u8 table_index;
+ struct mutex mappingtable_mutex;
+ struct mapping_table_entry mapping_table[RMI_SMB2_MAP_SIZE];
+};
+
+static int rmi_smb_get_version(struct rmi_smb_xport *rmi_smb)
+{
+ struct i2c_client *client = rmi_smb->client;
+ int retval;
+
+ /* Check if for SMBus new version device by reading version byte. */
+ retval = i2c_smbus_read_byte_data(client, SMB_PROTOCOL_VERSION_ADDRESS);
+ if (retval < 0) {
+ dev_err(&client->dev, "failed to get SMBus version number!\n");
+ return retval;
+ }
+ return retval + 1;
+}
+
+/* SMB block write - wrapper over ic2_smb_write_block */
+static int smb_block_write(struct rmi_transport_dev *xport,
+ u8 commandcode, const void *buf, size_t len)
+{
+ struct rmi_smb_xport *rmi_smb =
+ container_of(xport, struct rmi_smb_xport, xport);
+ struct i2c_client *client = rmi_smb->client;
+ int retval;
+
+ retval = i2c_smbus_write_block_data(client, commandcode, len, buf);
+
+ rmi_dbg(RMI_DEBUG_XPORT, &client->dev,
+ "wrote %zd bytes at %#04x: %d (%*ph)\n",
+ len, commandcode, retval, (int)len, buf);
+
+ return retval;
+}
+
+/*
+ * The function to get command code for smbus operations and keeps
+ * records to the driver mapping table
+ */
+static int rmi_smb_get_command_code(struct rmi_transport_dev *xport,
+ u16 rmiaddr, int bytecount, bool isread, u8 *commandcode)
+{
+ struct rmi_smb_xport *rmi_smb =
+ container_of(xport, struct rmi_smb_xport, xport);
+ int i;
+ int retval;
+ struct mapping_table_entry mapping_data[1];
+
+ mutex_lock(&rmi_smb->mappingtable_mutex);
+ for (i = 0; i < RMI_SMB2_MAP_SIZE; i++) {
+ if (rmi_smb->mapping_table[i].rmiaddr == rmiaddr) {
+ if (isread) {
+ if (rmi_smb->mapping_table[i].readcount
+ == bytecount) {
+ *commandcode = i;
+ retval = 0;
+ goto exit;
+ }
+ } else {
+ if (rmi_smb->mapping_table[i].flags &
+ RMI_SMB2_MAP_FLAGS_WE) {
+ *commandcode = i;
+ retval = 0;
+ goto exit;
+ }
+ }
+ }
+ }
+ i = rmi_smb->table_index;
+ rmi_smb->table_index = (i + 1) % RMI_SMB2_MAP_SIZE;
+
+ /* constructs mapping table data entry. 4 bytes each entry */
+ memset(mapping_data, 0, sizeof(mapping_data));
+
+ mapping_data[0].rmiaddr = cpu_to_le16(rmiaddr);
+ mapping_data[0].readcount = bytecount;
+ mapping_data[0].flags = !isread ? RMI_SMB2_MAP_FLAGS_WE : 0;
+
+ retval = smb_block_write(xport, i + 0x80, mapping_data,
+ sizeof(mapping_data));
+
+ if (retval < 0) {
+ /*
+ * if not written to device mapping table
+ * clear the driver mapping table records
+ */
+ rmi_smb->mapping_table[i].rmiaddr = 0x0000;
+ rmi_smb->mapping_table[i].readcount = 0;
+ rmi_smb->mapping_table[i].flags = 0;
+ goto exit;
+ }
+ /* save to the driver level mapping table */
+ rmi_smb->mapping_table[i].rmiaddr = rmiaddr;
+ rmi_smb->mapping_table[i].readcount = bytecount;
+ rmi_smb->mapping_table[i].flags = !isread ? RMI_SMB2_MAP_FLAGS_WE : 0;
+ *commandcode = i;
+
+exit:
+ mutex_unlock(&rmi_smb->mappingtable_mutex);
+
+ return retval;
+}
+
+static int rmi_smb_write_block(struct rmi_transport_dev *xport, u16 rmiaddr,
+ const void *databuff, size_t len)
+{
+ int retval = 0;
+ u8 commandcode;
+ struct rmi_smb_xport *rmi_smb =
+ container_of(xport, struct rmi_smb_xport, xport);
+ int cur_len = (int)len;
+
+ mutex_lock(&rmi_smb->page_mutex);
+
+ while (cur_len > 0) {
+ /*
+ * break into 32 bytes chunks to write get command code
+ */
+ int block_len = min_t(int, len, SMB_MAX_COUNT);
+
+ retval = rmi_smb_get_command_code(xport, rmiaddr, block_len,
+ false, &commandcode);
+ if (retval < 0)
+ goto exit;
+
+ retval = smb_block_write(xport, commandcode,
+ databuff, block_len);
+ if (retval < 0)
+ goto exit;
+
+ /* prepare to write next block of bytes */
+ cur_len -= SMB_MAX_COUNT;
+ databuff += SMB_MAX_COUNT;
+ rmiaddr += SMB_MAX_COUNT;
+ }
+exit:
+ mutex_unlock(&rmi_smb->page_mutex);
+ return retval;
+}
+
+/* SMB block read - wrapper over ic2_smb_read_block */
+static int smb_block_read(struct rmi_transport_dev *xport,
+ u8 commandcode, void *buf, size_t len)
+{
+ struct rmi_smb_xport *rmi_smb =
+ container_of(xport, struct rmi_smb_xport, xport);
+ struct i2c_client *client = rmi_smb->client;
+ int retval;
+
+ retval = i2c_smbus_read_block_data(client, commandcode, buf);
+ if (retval < 0)
+ return retval;
+
+ return retval;
+}
+
+static int rmi_smb_read_block(struct rmi_transport_dev *xport, u16 rmiaddr,
+ void *databuff, size_t len)
+{
+ struct rmi_smb_xport *rmi_smb =
+ container_of(xport, struct rmi_smb_xport, xport);
+ int retval;
+ u8 commandcode;
+ int cur_len = (int)len;
+
+ mutex_lock(&rmi_smb->page_mutex);
+ memset(databuff, 0, len);
+
+ while (cur_len > 0) {
+ /* break into 32 bytes chunks to write get command code */
+ int block_len = min_t(int, cur_len, SMB_MAX_COUNT);
+
+ retval = rmi_smb_get_command_code(xport, rmiaddr, block_len,
+ true, &commandcode);
+ if (retval < 0)
+ goto exit;
+
+ retval = smb_block_read(xport, commandcode,
+ databuff, block_len);
+ if (retval < 0)
+ goto exit;
+
+ /* prepare to read next block of bytes */
+ cur_len -= SMB_MAX_COUNT;
+ databuff += SMB_MAX_COUNT;
+ rmiaddr += SMB_MAX_COUNT;
+ }
+
+ retval = 0;
+
+exit:
+ mutex_unlock(&rmi_smb->page_mutex);
+ return retval;
+}
+
+static void rmi_smb_clear_state(struct rmi_smb_xport *rmi_smb)
+{
+ /* the mapping table has been flushed, discard the current one */
+ mutex_lock(&rmi_smb->mappingtable_mutex);
+ memset(rmi_smb->mapping_table, 0, sizeof(rmi_smb->mapping_table));
+ mutex_unlock(&rmi_smb->mappingtable_mutex);
+}
+
+static int rmi_smb_enable_smbus_mode(struct rmi_smb_xport *rmi_smb)
+{
+ int retval;
+
+ /* we need to get the smbus version to activate the touchpad */
+ retval = rmi_smb_get_version(rmi_smb);
+ if (retval < 0)
+ return retval;
+
+ return 0;
+}
+
+static int rmi_smb_reset(struct rmi_transport_dev *xport, u16 reset_addr)
+{
+ struct rmi_smb_xport *rmi_smb =
+ container_of(xport, struct rmi_smb_xport, xport);
+
+ rmi_smb_clear_state(rmi_smb);
+
+ /*
+ * we do not call the actual reset command, it has to be handled in
+ * PS/2 or there will be races between PS/2 and SMBus.
+ * PS/2 should ensure that a psmouse_reset is called before
+ * intializing the device and after it has been removed to be in a known
+ * state.
+ */
+ return rmi_smb_enable_smbus_mode(rmi_smb);
+}
+
+static const struct rmi_transport_ops rmi_smb_ops = {
+ .write_block = rmi_smb_write_block,
+ .read_block = rmi_smb_read_block,
+ .reset = rmi_smb_reset,
+};
+
+static void rmi_smb_alert(struct i2c_client *client,
+ enum i2c_alert_protocol type, unsigned int data)
+{
+ struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
+ struct rmi_device *rmi_dev = rmi_smb->xport.rmi_dev;
+ struct rmi_driver_data *drv_data = dev_get_drvdata(&rmi_dev->dev);
+
+ if (type != I2C_PROTOCOL_SMBUS_HOST_NOTIFY)
+ return;
+
+ if (!drv_data) {
+ dev_err(&client->dev,
+ "Something went wrong, driver data is NULL.\n");
+ return;
+ }
+
+ rmi_process_interrupt_requests(rmi_dev);
+}
+
+static int rmi_smb_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct rmi_device_platform_data *pdata = dev_get_platdata(&client->dev);
+ struct rmi_smb_xport *rmi_smb;
+ int retval;
+ int smbus_version;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_READ_BLOCK_DATA |
+ I2C_FUNC_SMBUS_HOST_NOTIFY)) {
+ dev_err(&client->dev,
+ "adapter does not support required functionality.\n");
+ return -ENODEV;
+ }
+
+ rmi_smb = devm_kzalloc(&client->dev, sizeof(struct rmi_smb_xport),
+ GFP_KERNEL);
+ if (!rmi_smb)
+ return -ENOMEM;
+
+ if (!pdata) {
+ dev_err(&client->dev, "no platform data, aborting\n");
+ return -ENOMEM;
+ }
+
+ rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Probing %s.\n",
+ dev_name(&client->dev));
+
+ rmi_smb->client = client;
+ mutex_init(&rmi_smb->page_mutex);
+ mutex_init(&rmi_smb->mappingtable_mutex);
+
+ rmi_smb->xport.dev = &client->dev;
+ rmi_smb->xport.pdata = *pdata;
+ rmi_smb->xport.proto_name = "smb2";
+ rmi_smb->xport.ops = &rmi_smb_ops;
+
+ retval = rmi_smb_get_version(rmi_smb);
+ if (retval < 0)
+ return retval;
+
+ smbus_version = retval;
+ rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Smbus version is %d",
+ smbus_version);
+
+ if (smbus_version != 2) {
+ dev_err(&client->dev, "Unrecognized SMB version %d.\n",
+ smbus_version);
+ return -ENODEV;
+ }
+
+ i2c_set_clientdata(client, rmi_smb);
+
+ retval = rmi_register_transport_device(&rmi_smb->xport);
+ if (retval) {
+ dev_err(&client->dev, "Failed to register transport driver at 0x%.2X.\n",
+ client->addr);
+ i2c_set_clientdata(client, NULL);
+ return retval;
+ }
+
+ dev_info(&client->dev, "registered rmi smb driver at %#04x.\n",
+ client->addr);
+ return 0;
+
+}
+
+static int rmi_smb_remove(struct i2c_client *client)
+{
+ struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
+
+ rmi_unregister_transport_device(&rmi_smb->xport);
+
+ return 0;
+}
+
+static int __maybe_unused rmi_smb_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
+ int ret;
+
+ ret = rmi_driver_suspend(rmi_smb->xport.rmi_dev);
+ if (ret)
+ dev_warn(dev, "Failed to suspend device: %d\n", ret);
+
+ return ret;
+}
+
+static int __maybe_unused rmi_smb_resume(struct device *dev)
+{
+ struct i2c_client *client = container_of(dev, struct i2c_client, dev);
+ struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
+ struct rmi_device *rmi_dev = rmi_smb->xport.rmi_dev;
+ int ret;
+
+ rmi_smb_reset(&rmi_smb->xport, 0);
+
+ rmi_reset(rmi_dev);
+
+ ret = rmi_driver_resume(rmi_smb->xport.rmi_dev);
+ if (ret)
+ dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+ return 0;
+}
+
+static int __maybe_unused rmi_smb_runtime_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
+ int ret;
+
+ ret = rmi_driver_resume(rmi_smb->xport.rmi_dev);
+ if (ret)
+ dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+ return 0;
+}
+
+static const struct dev_pm_ops rmi_smb_pm = {
+ SET_SYSTEM_SLEEP_PM_OPS(rmi_smb_suspend, rmi_smb_resume)
+ SET_RUNTIME_PM_OPS(rmi_smb_suspend, rmi_smb_runtime_resume,
+ NULL)
+};
+
+static const struct i2c_device_id rmi_id[] = {
+ { "rmi4_smbus", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, rmi_id);
+
+static struct i2c_driver rmi_smb_driver = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "rmi4_smbus",
+ .pm = &rmi_smb_pm,
+ },
+ .id_table = rmi_id,
+ .probe = rmi_smb_probe,
+ .remove = rmi_smb_remove,
+ .alert = rmi_smb_alert,
+};
+
+module_i2c_driver(rmi_smb_driver);
+
+MODULE_AUTHOR("Andrew Duggan <aduggan@xxxxxxxxxxxxx>");
+MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>");
+MODULE_DESCRIPTION("RMI4 SMBus driver");
+MODULE_LICENSE("GPL");
--
2.5.5

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