--- /dev/null
+/*
+ * IBM OPAL I2C driver
+ * Copyright (C) 2014 IBM
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.
+ */
+
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <asm/firmware.h>
+#include <asm/opal.h>
+
+static int i2c_opal_translate_error(int rc)
+{
+ switch (rc) {
+ case OPAL_NO_MEM:
+ return -ENOMEM;
+ case OPAL_PARAMETER:
+ return -EINVAL;
+ case OPAL_I2C_ARBT_LOST:
+ return -EAGAIN;
+ case OPAL_I2C_TIMEOUT:
+ return -ETIMEDOUT;
+ case OPAL_I2C_NACK_RCVD:
+ return -ENXIO;
+ case OPAL_I2C_STOP_ERR:
+ return -EBUSY;
+ default:
+ return -EIO;
+ }
+}
+
+static int i2c_opal_send_request(u32 bus_id, struct opal_i2c_request *req)
+{
+ struct opal_msg msg;
+ int token, rc;
+
+ token = opal_async_get_token_interruptible();
+ if (token < 0) {
+ if (token != -ERESTARTSYS)
+ pr_err("Failed to get the async token\n");
+
+ return token;
+ }
+
+ rc = opal_i2c_request(token, bus_id, req);
+ if (rc != OPAL_ASYNC_COMPLETION) {
+ rc = i2c_opal_translate_error(rc);
+ goto exit;
+ }
+
+ rc = opal_async_wait_response(token, &msg);
+ if (rc)
+ goto exit;
+
+ rc = be64_to_cpu(msg.params[1]);
+ if (rc != OPAL_SUCCESS) {
+ rc = i2c_opal_translate_error(rc);
+ goto exit;
+ }
+
+exit:
+ opal_async_release_token(token);
+ return rc;
+}
+
+static int i2c_opal_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num)
+{
+ unsigned long opal_id = (unsigned long)adap->algo_data;
+ struct opal_i2c_request req;
+ int rc, i;
+
+ /* We only support fairly simple combinations here of one
+ * or two messages
+ */
+ memset(&req, 0, sizeof(req));
+ switch(num) {
+ case 0:
+ return 0;
+ case 1:
+ req.type = (msgs[0].flags & I2C_M_RD) ?
+ OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
+ req.addr = cpu_to_be16(msgs[0].addr);
+ req.size = cpu_to_be32(msgs[0].len);
+ req.buffer_ra = cpu_to_be64(__pa(msgs[0].buf));
+ break;
+ case 2:
+ req.type = (msgs[1].flags & I2C_M_RD) ?
+ OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
+ req.addr = cpu_to_be16(msgs[0].addr);
+ req.subaddr_sz = msgs[0].len;
+ for (i = 0; i < msgs[0].len; i++)
+ req.subaddr = (req.subaddr << 8) | msgs[0].buf[i];
+ req.subaddr = cpu_to_be32(req.subaddr);
+ req.size = cpu_to_be32(msgs[1].len);
+ req.buffer_ra = cpu_to_be64(__pa(msgs[1].buf));
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ rc = i2c_opal_send_request(opal_id, &req);
+ if (rc)
+ return rc;
+
+ return num;
+}
+
+static int i2c_opal_smbus_xfer(struct i2c_adapter *adap, u16 addr,
+ unsigned short flags, char read_write,
+ u8 command, int size, union i2c_smbus_data *data)
+{
+ unsigned long opal_id = (unsigned long)adap->algo_data;
+ struct opal_i2c_request req;
+ u8 local[2];
+ int rc;
+
+ memset(&req, 0, sizeof(req));
+
+ req.addr = cpu_to_be16(addr);
+ switch (size) {
+ case I2C_SMBUS_BYTE:
+ req.buffer_ra = cpu_to_be64(__pa(&data->byte));
+ req.size = cpu_to_be32(1);
+ /* Fall through */
+ case I2C_SMBUS_QUICK:
+ req.type = (read_write == I2C_SMBUS_READ) ?
+ OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
+ break;
+ case I2C_SMBUS_BYTE_DATA:
+ req.buffer_ra = cpu_to_be64(__pa(&data->byte));
+ req.size = cpu_to_be32(1);
+ req.subaddr = cpu_to_be32(command);
+ req.subaddr_sz = 1;
+ req.type = (read_write == I2C_SMBUS_READ) ?
+ OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
+ break;
+ case I2C_SMBUS_WORD_DATA:
+ if (!read_write) {
+ local[0] = data->word & 0xff;
+ local[1] = (data->word >> 8) & 0xff;
+ }
+ req.buffer_ra = cpu_to_be64(__pa(local));
+ req.size = cpu_to_be32(2);
+ req.subaddr = cpu_to_be32(command);
+ req.subaddr_sz = 1;
+ req.type = (read_write == I2C_SMBUS_READ) ?
+ OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
+ break;
+ case I2C_SMBUS_I2C_BLOCK_DATA:
+ req.buffer_ra = cpu_to_be64(__pa(&data->block[1]));
+ req.size = cpu_to_be32(data->block[0]);
+ req.subaddr = cpu_to_be32(command);
+ req.subaddr_sz = 1;
+ req.type = (read_write == I2C_SMBUS_READ) ?
+ OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ rc = i2c_opal_send_request(opal_id, &req);
+ if (!rc && read_write && size == I2C_SMBUS_WORD_DATA) {
+ data->word = ((u16)local[1]) << 8;
+ data->word |= local[0];
+ }
+
+ return rc;
+}
+
+static u32 i2c_opal_func(struct i2c_adapter *adapter)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
+ I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
+ I2C_FUNC_SMBUS_I2C_BLOCK;
+}
+
+static const struct i2c_algorithm i2c_opal_algo = {
+ .master_xfer = i2c_opal_master_xfer,
+ .smbus_xfer = i2c_opal_smbus_xfer,
+ .functionality = i2c_opal_func,
+};
+
+/*
+ * For two messages, we basically support simple smbus transactions of a
+ * write-then-anything.
+ */
+static struct i2c_adapter_quirks i2c_opal_quirks = {
+ .flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_SAME_ADDR,
+ .max_comb_1st_msg_len = 4,
+};
+
+static int i2c_opal_probe(struct platform_device *pdev)
+{
+ struct i2c_adapter *adapter;
+ const char *pname;
+ u32 opal_id;
+ int rc;
+
+ if (!pdev->dev.of_node)
+ return -ENODEV;
+
+ rc = of_property_read_u32(pdev->dev.of_node, "ibm,opal-id", &opal_id);
+ if (rc) {
+ dev_err(&pdev->dev, "Missing ibm,opal-id property !\n");
+ return -EIO;
+ }
+
+ adapter = devm_kzalloc(&pdev->dev, sizeof(*adapter), GFP_KERNEL);
+ if (!adapter)
+ return -ENOMEM;
+
+ adapter->algo = &i2c_opal_algo;
+ adapter->algo_data = (void *)(unsigned long)opal_id;
+ adapter->quirks = &i2c_opal_quirks;
+ adapter->dev.parent = &pdev->dev;
+ adapter->dev.of_node = of_node_get(pdev->dev.of_node);
+ pname = of_get_property(pdev->dev.of_node, "ibm,port-name", NULL);
+ if (pname)
+ strlcpy(adapter->name, pname, sizeof(adapter->name));
+ else
+ strlcpy(adapter->name, "opal", sizeof(adapter->name));
+
+ platform_set_drvdata(pdev, adapter);
+ rc = i2c_add_adapter(adapter);
+ if (rc)
+ dev_err(&pdev->dev, "Failed to register the i2c adapter\n");
+
+ return rc;
+}
+
+static int i2c_opal_remove(struct platform_device *pdev)
+{
+ struct i2c_adapter *adapter = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(adapter);
+
+ return 0;
+}
+
+static const struct of_device_id i2c_opal_of_match[] = {
+ {
+ .compatible = "ibm,opal-i2c",
+ },
+ { }
+};
+MODULE_DEVICE_TABLE(of, i2c_opal_of_match);
+
+static struct platform_driver i2c_opal_driver = {
+ .probe = i2c_opal_probe,
+ .remove = i2c_opal_remove,
+ .driver = {
+ .name = "i2c-opal",
+ .of_match_table = i2c_opal_of_match,
+ },
+};
+
+static int __init i2c_opal_init(void)
+{
+ if (!firmware_has_feature(FW_FEATURE_OPAL))
+ return -ENODEV;
+
+ return platform_driver_register(&i2c_opal_driver);
+}
+module_init(i2c_opal_init);
+
+static void __exit i2c_opal_exit(void)
+{
+ return platform_driver_unregister(&i2c_opal_driver);
+}
+module_exit(i2c_opal_exit);
+
+MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
+MODULE_DESCRIPTION("IBM OPAL I2C driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff