// SPDX-License-Identifier: GPL-2.0 /* Copyright (C) IBM Corporation 2023 */ #include #include #include #include #include #include #include "fsi-master-i2cr.h" #define CREATE_TRACE_POINTS #include #define I2CR_ADDRESS_CFAM(a) ((a) >> 2) #define I2CR_INITIAL_PARITY true #define I2CR_STATUS_CMD 0x60002 #define I2CR_STATUS_ERR BIT_ULL(61) #define I2CR_ERROR_CMD 0x60004 #define I2CR_LOG_CMD 0x60008 static const u8 i2cr_cfam[] = { 0xc0, 0x02, 0x0d, 0xa6, 0x80, 0x01, 0x10, 0x02, 0x80, 0x01, 0x10, 0x02, 0x80, 0x01, 0x10, 0x02, 0x80, 0x01, 0x80, 0x52, 0x80, 0x01, 0x10, 0x02, 0x80, 0x01, 0x10, 0x02, 0x80, 0x01, 0x10, 0x02, 0x80, 0x01, 0x10, 0x02, 0x80, 0x01, 0x22, 0x2d, 0x00, 0x00, 0x00, 0x00, 0xde, 0xad, 0xc0, 0xde }; static bool i2cr_check_parity32(u32 v, bool parity) { u32 i; for (i = 0; i < 32; ++i) { if (v & (1u << i)) parity = !parity; } return parity; } static bool i2cr_check_parity64(u64 v) { u32 i; bool parity = I2CR_INITIAL_PARITY; for (i = 0; i < 64; ++i) { if (v & (1llu << i)) parity = !parity; } return parity; } static u32 i2cr_get_command(u32 address, bool parity) { address <<= 1; if (i2cr_check_parity32(address, parity)) address |= 1; return address; } static int i2cr_transfer(struct i2c_client *client, u32 command, u64 *data) { struct i2c_msg msgs[2]; int ret; msgs[0].addr = client->addr; msgs[0].flags = 0; msgs[0].len = sizeof(command); msgs[0].buf = (__u8 *)&command; msgs[1].addr = client->addr; msgs[1].flags = I2C_M_RD; msgs[1].len = sizeof(*data); msgs[1].buf = (__u8 *)data; ret = i2c_transfer(client->adapter, msgs, 2); if (ret == 2) return 0; trace_i2cr_i2c_error(client, command, ret); if (ret < 0) return ret; return -EIO; } static int i2cr_check_status(struct i2c_client *client) { u64 status; int ret; ret = i2cr_transfer(client, I2CR_STATUS_CMD, &status); if (ret) return ret; if (status & I2CR_STATUS_ERR) { u32 buf[3] = { 0, 0, 0 }; u64 error; u64 log; i2cr_transfer(client, I2CR_ERROR_CMD, &error); i2cr_transfer(client, I2CR_LOG_CMD, &log); trace_i2cr_status_error(client, status, error, log); buf[0] = I2CR_STATUS_CMD; i2c_master_send(client, (const char *)buf, sizeof(buf)); buf[0] = I2CR_ERROR_CMD; i2c_master_send(client, (const char *)buf, sizeof(buf)); buf[0] = I2CR_LOG_CMD; i2c_master_send(client, (const char *)buf, sizeof(buf)); dev_err(&client->dev, "status:%016llx error:%016llx log:%016llx\n", status, error, log); return -EREMOTEIO; } trace_i2cr_status(client, status); return 0; } int fsi_master_i2cr_read(struct fsi_master_i2cr *i2cr, u32 addr, u64 *data) { u32 command = i2cr_get_command(addr, I2CR_INITIAL_PARITY); int ret; mutex_lock(&i2cr->lock); ret = i2cr_transfer(i2cr->client, command, data); if (ret) goto unlock; ret = i2cr_check_status(i2cr->client); if (ret) goto unlock; trace_i2cr_read(i2cr->client, command, data); unlock: mutex_unlock(&i2cr->lock); return ret; } EXPORT_SYMBOL_GPL(fsi_master_i2cr_read); int fsi_master_i2cr_write(struct fsi_master_i2cr *i2cr, u32 addr, u64 data) { u32 buf[3] = { 0 }; int ret; buf[0] = i2cr_get_command(addr, i2cr_check_parity64(data)); memcpy(&buf[1], &data, sizeof(data)); mutex_lock(&i2cr->lock); ret = i2c_master_send(i2cr->client, (const char *)buf, sizeof(buf)); if (ret == sizeof(buf)) { ret = i2cr_check_status(i2cr->client); if (!ret) trace_i2cr_write(i2cr->client, buf[0], data); } else { trace_i2cr_i2c_error(i2cr->client, buf[0], ret); if (ret >= 0) ret = -EIO; } mutex_unlock(&i2cr->lock); return ret; } EXPORT_SYMBOL_GPL(fsi_master_i2cr_write); static int i2cr_read(struct fsi_master *master, int link, uint8_t id, uint32_t addr, void *val, size_t size) { struct fsi_master_i2cr *i2cr = container_of(master, struct fsi_master_i2cr, master); u64 data; size_t i; int ret; if (link || id || (addr & 0xffff0000) || !(size == 1 || size == 2 || size == 4)) return -EINVAL; /* * The I2CR doesn't have CFAM or FSI slave address space - only the * engines. In order for this to work with the FSI core, we need to * emulate at minimum the CFAM config table so that the appropriate * engines are discovered. */ if (addr < 0xc00) { if (addr > sizeof(i2cr_cfam) - 4) addr = (addr & 0x3) + (sizeof(i2cr_cfam) - 4); memcpy(val, &i2cr_cfam[addr], size); return 0; } ret = fsi_master_i2cr_read(i2cr, I2CR_ADDRESS_CFAM(addr), &data); if (ret) return ret; /* * FSI core expects up to 4 bytes BE back, while I2CR replied with LE * bytes on the wire. */ for (i = 0; i < size; ++i) ((u8 *)val)[i] = ((u8 *)&data)[7 - i]; return 0; } static int i2cr_write(struct fsi_master *master, int link, uint8_t id, uint32_t addr, const void *val, size_t size) { struct fsi_master_i2cr *i2cr = container_of(master, struct fsi_master_i2cr, master); u64 data = 0; size_t i; if (link || id || (addr & 0xffff0000) || !(size == 1 || size == 2 || size == 4)) return -EINVAL; /* I2CR writes to CFAM or FSI slave address are a successful no-op. */ if (addr < 0xc00) return 0; /* * FSI core passes up to 4 bytes BE, while the I2CR expects LE bytes on * the wire. */ for (i = 0; i < size; ++i) ((u8 *)&data)[7 - i] = ((u8 *)val)[i]; return fsi_master_i2cr_write(i2cr, I2CR_ADDRESS_CFAM(addr), data); } static void i2cr_release(struct device *dev) { struct fsi_master_i2cr *i2cr = to_fsi_master_i2cr(to_fsi_master(dev)); of_node_put(dev->of_node); kfree(i2cr); } static int i2cr_probe(struct i2c_client *client) { struct fsi_master_i2cr *i2cr; int ret; i2cr = kzalloc(sizeof(*i2cr), GFP_KERNEL); if (!i2cr) return -ENOMEM; /* Only one I2CR on any given I2C bus (fixed I2C device address) */ i2cr->master.idx = client->adapter->nr; dev_set_name(&i2cr->master.dev, "i2cr%d", i2cr->master.idx); i2cr->master.dev.parent = &client->dev; i2cr->master.dev.of_node = of_node_get(dev_of_node(&client->dev)); i2cr->master.dev.release = i2cr_release; i2cr->master.n_links = 1; i2cr->master.read = i2cr_read; i2cr->master.write = i2cr_write; mutex_init(&i2cr->lock); i2cr->client = client; ret = fsi_master_register(&i2cr->master); if (ret) return ret; i2c_set_clientdata(client, i2cr); return 0; } static void i2cr_remove(struct i2c_client *client) { struct fsi_master_i2cr *i2cr = i2c_get_clientdata(client); fsi_master_unregister(&i2cr->master); } static const struct of_device_id i2cr_ids[] = { { .compatible = "ibm,i2cr-fsi-master" }, { } }; MODULE_DEVICE_TABLE(of, i2cr_ids); static struct i2c_driver i2cr_driver = { .probe = i2cr_probe, .remove = i2cr_remove, .driver = { .name = "fsi-master-i2cr", .of_match_table = i2cr_ids, }, }; module_i2c_driver(i2cr_driver) MODULE_AUTHOR("Eddie James "); MODULE_DESCRIPTION("IBM I2C Responder virtual FSI master driver"); MODULE_LICENSE("GPL");