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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-09-15 13:54:11 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-09-15 13:54:11 +0200
commitc1aa01c96e590714d99c5f17cfae1b14dec8bdee (patch)
tree5811422f65efdff3fd89fdaf9a8c6d7d1cc4d06b /greybus_i2c.patch
parent4758ee8bc89a86c2110b9e85878538ced8045ef5 (diff)
downloadpatches-c1aa01c96e590714d99c5f17cfae1b14dec8bdee.tar.gz
greybus patches
Diffstat (limited to 'greybus_i2c.patch')
-rw-r--r--greybus_i2c.patch350
1 files changed, 350 insertions, 0 deletions
diff --git a/greybus_i2c.patch b/greybus_i2c.patch
new file mode 100644
index 00000000000000..e739a058e339b5
--- /dev/null
+++ b/greybus_i2c.patch
@@ -0,0 +1,350 @@
+---
+ drivers/greybus/i2c.c | 343 ++++++++++++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 343 insertions(+)
+
+--- /dev/null
++++ b/drivers/greybus/i2c.c
+@@ -0,0 +1,343 @@
++/*
++ * I2C bridge driver for the Greybus "generic" I2C module.
++ *
++ * Copyright 2014 Google Inc.
++ * Copyright 2014 Linaro Ltd.
++ *
++ * Released under the GPLv2 only.
++ */
++
++#include <linux/kernel.h>
++#include <linux/module.h>
++#include <linux/slab.h>
++#include <linux/i2c.h>
++
++#include "greybus.h"
++#include "gbphy.h"
++
++struct gb_i2c_device {
++ struct gb_connection *connection;
++ struct gbphy_device *gbphy_dev;
++
++ u32 functionality;
++
++ struct i2c_adapter adapter;
++};
++
++/*
++ * Map Greybus i2c functionality bits into Linux ones
++ */
++static u32 gb_i2c_functionality_map(u32 gb_i2c_functionality)
++{
++ return gb_i2c_functionality; /* All bits the same for now */
++}
++
++static int gb_i2c_functionality_operation(struct gb_i2c_device *gb_i2c_dev)
++{
++ struct gb_i2c_functionality_response response;
++ u32 functionality;
++ int ret;
++
++ ret = gb_operation_sync(gb_i2c_dev->connection,
++ GB_I2C_TYPE_FUNCTIONALITY,
++ NULL, 0, &response, sizeof(response));
++ if (ret)
++ return ret;
++
++ functionality = le32_to_cpu(response.functionality);
++ gb_i2c_dev->functionality = gb_i2c_functionality_map(functionality);
++
++ return 0;
++}
++
++/*
++ * Map Linux i2c_msg flags into Greybus i2c transfer op flags.
++ */
++static u16 gb_i2c_transfer_op_flags_map(u16 flags)
++{
++ return flags; /* All flags the same for now */
++}
++
++static void
++gb_i2c_fill_transfer_op(struct gb_i2c_transfer_op *op, struct i2c_msg *msg)
++{
++ u16 flags = gb_i2c_transfer_op_flags_map(msg->flags);
++
++ op->addr = cpu_to_le16(msg->addr);
++ op->flags = cpu_to_le16(flags);
++ op->size = cpu_to_le16(msg->len);
++}
++
++static struct gb_operation *
++gb_i2c_operation_create(struct gb_connection *connection,
++ struct i2c_msg *msgs, u32 msg_count)
++{
++ struct gb_i2c_device *gb_i2c_dev = gb_connection_get_data(connection);
++ struct gb_i2c_transfer_request *request;
++ struct gb_operation *operation;
++ struct gb_i2c_transfer_op *op;
++ struct i2c_msg *msg;
++ u32 data_out_size = 0;
++ u32 data_in_size = 0;
++ size_t request_size;
++ void *data;
++ u16 op_count;
++ u32 i;
++
++ if (msg_count > (u32)U16_MAX) {
++ dev_err(&gb_i2c_dev->gbphy_dev->dev, "msg_count (%u) too big\n",
++ msg_count);
++ return NULL;
++ }
++ op_count = (u16)msg_count;
++
++ /*
++ * In addition to space for all message descriptors we need
++ * to have enough to hold all outbound message data.
++ */
++ msg = msgs;
++ for (i = 0; i < msg_count; i++, msg++)
++ if (msg->flags & I2C_M_RD)
++ data_in_size += (u32)msg->len;
++ else
++ data_out_size += (u32)msg->len;
++
++ request_size = sizeof(*request);
++ request_size += msg_count * sizeof(*op);
++ request_size += data_out_size;
++
++ /* Response consists only of incoming data */
++ operation = gb_operation_create(connection, GB_I2C_TYPE_TRANSFER,
++ request_size, data_in_size, GFP_KERNEL);
++ if (!operation)
++ return NULL;
++
++ request = operation->request->payload;
++ request->op_count = cpu_to_le16(op_count);
++ /* Fill in the ops array */
++ op = &request->ops[0];
++ msg = msgs;
++ for (i = 0; i < msg_count; i++)
++ gb_i2c_fill_transfer_op(op++, msg++);
++
++ if (!data_out_size)
++ return operation;
++
++ /* Copy over the outgoing data; it starts after the last op */
++ data = op;
++ msg = msgs;
++ for (i = 0; i < msg_count; i++) {
++ if (!(msg->flags & I2C_M_RD)) {
++ memcpy(data, msg->buf, msg->len);
++ data += msg->len;
++ }
++ msg++;
++ }
++
++ return operation;
++}
++
++static void gb_i2c_decode_response(struct i2c_msg *msgs, u32 msg_count,
++ struct gb_i2c_transfer_response *response)
++{
++ struct i2c_msg *msg = msgs;
++ u8 *data;
++ u32 i;
++
++ if (!response)
++ return;
++ data = response->data;
++ for (i = 0; i < msg_count; i++) {
++ if (msg->flags & I2C_M_RD) {
++ memcpy(msg->buf, data, msg->len);
++ data += msg->len;
++ }
++ msg++;
++ }
++}
++
++/*
++ * Some i2c transfer operations return results that are expected.
++ */
++static bool gb_i2c_expected_transfer_error(int errno)
++{
++ return errno == -EAGAIN || errno == -ENODEV;
++}
++
++static int gb_i2c_transfer_operation(struct gb_i2c_device *gb_i2c_dev,
++ struct i2c_msg *msgs, u32 msg_count)
++{
++ struct gb_connection *connection = gb_i2c_dev->connection;
++ struct device *dev = &gb_i2c_dev->gbphy_dev->dev;
++ struct gb_operation *operation;
++ int ret;
++
++ operation = gb_i2c_operation_create(connection, msgs, msg_count);
++ if (!operation)
++ return -ENOMEM;
++
++ ret = gbphy_runtime_get_sync(gb_i2c_dev->gbphy_dev);
++ if (ret)
++ goto exit_operation_put;
++
++ ret = gb_operation_request_send_sync(operation);
++ if (!ret) {
++ struct gb_i2c_transfer_response *response;
++
++ response = operation->response->payload;
++ gb_i2c_decode_response(msgs, msg_count, response);
++ ret = msg_count;
++ } else if (!gb_i2c_expected_transfer_error(ret)) {
++ dev_err(dev, "transfer operation failed (%d)\n", ret);
++ }
++
++ gbphy_runtime_put_autosuspend(gb_i2c_dev->gbphy_dev);
++
++exit_operation_put:
++ gb_operation_put(operation);
++
++ return ret;
++}
++
++static int gb_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
++ int msg_count)
++{
++ struct gb_i2c_device *gb_i2c_dev;
++
++ gb_i2c_dev = i2c_get_adapdata(adap);
++
++ return gb_i2c_transfer_operation(gb_i2c_dev, msgs, msg_count);
++}
++
++#if 0
++/* Later */
++static int gb_i2c_smbus_xfer(struct i2c_adapter *adap,
++ u16 addr, unsigned short flags, char read_write,
++ u8 command, int size, union i2c_smbus_data *data)
++{
++ struct gb_i2c_device *gb_i2c_dev;
++
++ gb_i2c_dev = i2c_get_adapdata(adap);
++
++ return 0;
++}
++#endif
++
++static u32 gb_i2c_functionality(struct i2c_adapter *adap)
++{
++ struct gb_i2c_device *gb_i2c_dev = i2c_get_adapdata(adap);
++
++ return gb_i2c_dev->functionality;
++}
++
++static const struct i2c_algorithm gb_i2c_algorithm = {
++ .master_xfer = gb_i2c_master_xfer,
++ /* .smbus_xfer = gb_i2c_smbus_xfer, */
++ .functionality = gb_i2c_functionality,
++};
++
++/*
++ * Do initial setup of the i2c device. This includes verifying we
++ * can support it (based on the protocol version it advertises).
++ * If that's OK, we get and cached its functionality bits.
++ *
++ * Note: gb_i2c_dev->connection is assumed to have been valid.
++ */
++static int gb_i2c_device_setup(struct gb_i2c_device *gb_i2c_dev)
++{
++ /* Assume the functionality never changes, just get it once */
++ return gb_i2c_functionality_operation(gb_i2c_dev);
++}
++
++static int gb_i2c_probe(struct gbphy_device *gbphy_dev,
++ const struct gbphy_device_id *id)
++{
++ struct gb_connection *connection;
++ struct gb_i2c_device *gb_i2c_dev;
++ struct i2c_adapter *adapter;
++ int ret;
++
++ gb_i2c_dev = kzalloc(sizeof(*gb_i2c_dev), GFP_KERNEL);
++ if (!gb_i2c_dev)
++ return -ENOMEM;
++
++ connection = gb_connection_create(gbphy_dev->bundle,
++ le16_to_cpu(gbphy_dev->cport_desc->id),
++ NULL);
++ if (IS_ERR(connection)) {
++ ret = PTR_ERR(connection);
++ goto exit_i2cdev_free;
++ }
++
++ gb_i2c_dev->connection = connection;
++ gb_connection_set_data(connection, gb_i2c_dev);
++ gb_i2c_dev->gbphy_dev = gbphy_dev;
++ gb_gbphy_set_data(gbphy_dev, gb_i2c_dev);
++
++ ret = gb_connection_enable(connection);
++ if (ret)
++ goto exit_connection_destroy;
++
++ ret = gb_i2c_device_setup(gb_i2c_dev);
++ if (ret)
++ goto exit_connection_disable;
++
++ /* Looks good; up our i2c adapter */
++ adapter = &gb_i2c_dev->adapter;
++ adapter->owner = THIS_MODULE;
++ adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
++ adapter->algo = &gb_i2c_algorithm;
++ /* adapter->algo_data = what? */
++
++ adapter->dev.parent = &gbphy_dev->dev;
++ snprintf(adapter->name, sizeof(adapter->name), "Greybus i2c adapter");
++ i2c_set_adapdata(adapter, gb_i2c_dev);
++
++ ret = i2c_add_adapter(adapter);
++ if (ret)
++ goto exit_connection_disable;
++
++ gbphy_runtime_put_autosuspend(gbphy_dev);
++ return 0;
++
++exit_connection_disable:
++ gb_connection_disable(connection);
++exit_connection_destroy:
++ gb_connection_destroy(connection);
++exit_i2cdev_free:
++ kfree(gb_i2c_dev);
++
++ return ret;
++}
++
++static void gb_i2c_remove(struct gbphy_device *gbphy_dev)
++{
++ struct gb_i2c_device *gb_i2c_dev = gb_gbphy_get_data(gbphy_dev);
++ struct gb_connection *connection = gb_i2c_dev->connection;
++ int ret;
++
++ ret = gbphy_runtime_get_sync(gbphy_dev);
++ if (ret)
++ gbphy_runtime_get_noresume(gbphy_dev);
++
++ i2c_del_adapter(&gb_i2c_dev->adapter);
++ gb_connection_disable(connection);
++ gb_connection_destroy(connection);
++ kfree(gb_i2c_dev);
++}
++
++static const struct gbphy_device_id gb_i2c_id_table[] = {
++ { GBPHY_PROTOCOL(GREYBUS_PROTOCOL_I2C) },
++ { },
++};
++MODULE_DEVICE_TABLE(gbphy, gb_i2c_id_table);
++
++static struct gbphy_driver i2c_driver = {
++ .name = "i2c",
++ .probe = gb_i2c_probe,
++ .remove = gb_i2c_remove,
++ .id_table = gb_i2c_id_table,
++};
++
++module_gbphy_driver(i2c_driver);
++MODULE_LICENSE("GPL v2");
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