/* * drivers/net/ethernet/mellanox/mlxsw/i2c.c * Copyright (c) 2016 Mellanox Technologies. All rights reserved. * Copyright (c) 2016 Vadim Pasternak * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the names of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include "cmd.h" #include "core.h" #include "i2c.h" static const char mlxsw_i2c_driver_name[] = "mlxsw_i2c"; #define MLXSW_I2C_CIR2_BASE 0x72000 #define MLXSW_I2C_CIR_STATUS_OFF 0x18 #define MLXSW_I2C_CIR2_OFF_STATUS (MLXSW_I2C_CIR2_BASE + \ MLXSW_I2C_CIR_STATUS_OFF) #define MLXSW_I2C_OPMOD_SHIFT 12 #define MLXSW_I2C_GO_BIT_SHIFT 23 #define MLXSW_I2C_CIR_CTRL_STATUS_SHIFT 24 #define MLXSW_I2C_GO_BIT BIT(MLXSW_I2C_GO_BIT_SHIFT) #define MLXSW_I2C_GO_OPMODE BIT(MLXSW_I2C_OPMOD_SHIFT) #define MLXSW_I2C_SET_IMM_CMD (MLXSW_I2C_GO_OPMODE | \ MLXSW_CMD_OPCODE_QUERY_FW) #define MLXSW_I2C_PUSH_IMM_CMD (MLXSW_I2C_GO_BIT | \ MLXSW_I2C_SET_IMM_CMD) #define MLXSW_I2C_SET_CMD (MLXSW_CMD_OPCODE_ACCESS_REG) #define MLXSW_I2C_PUSH_CMD (MLXSW_I2C_GO_BIT | MLXSW_I2C_SET_CMD) #define MLXSW_I2C_TLV_HDR_SIZE 0x10 #define MLXSW_I2C_ADDR_WIDTH 4 #define MLXSW_I2C_PUSH_CMD_SIZE (MLXSW_I2C_ADDR_WIDTH + 4) #define MLXSW_I2C_READ_SEMA_SIZE 4 #define MLXSW_I2C_PREP_SIZE (MLXSW_I2C_ADDR_WIDTH + 28) #define MLXSW_I2C_MBOX_SIZE 20 #define MLXSW_I2C_MBOX_OUT_PARAM_OFF 12 #define MLXSW_I2C_MAX_BUFF_SIZE 32 #define MLXSW_I2C_MBOX_OFFSET_BITS 20 #define MLXSW_I2C_MBOX_SIZE_BITS 12 #define MLXSW_I2C_ADDR_BUF_SIZE 4 #define MLXSW_I2C_BLK_MAX 32 #define MLXSW_I2C_RETRY 5 #define MLXSW_I2C_TIMEOUT_MSECS 5000 /** * struct mlxsw_i2c - device private data: * @cmd.mb_size_in: input mailbox size; * @cmd.mb_off_in: input mailbox offset in register space; * @cmd.mb_size_out: output mailbox size; * @cmd.mb_off_out: output mailbox offset in register space; * @cmd.lock: command execution lock; * @dev: I2C device; * @core: switch core pointer; * @bus_info: bus info block; */ struct mlxsw_i2c { struct { u32 mb_size_in; u32 mb_off_in; u32 mb_size_out; u32 mb_off_out; struct mutex lock; } cmd; struct device *dev; struct mlxsw_core *core; struct mlxsw_bus_info bus_info; }; #define MLXSW_I2C_READ_MSG(_client, _addr_buf, _buf, _len) { \ { .addr = (_client)->addr, \ .buf = (_addr_buf), \ .len = MLXSW_I2C_ADDR_BUF_SIZE, \ .flags = 0 }, \ { .addr = (_client)->addr, \ .buf = (_buf), \ .len = (_len), \ .flags = I2C_M_RD } } #define MLXSW_I2C_WRITE_MSG(_client, _buf, _len) \ { .addr = (_client)->addr, \ .buf = (u8 *)(_buf), \ .len = (_len), \ .flags = 0 } /* Routine converts in and out mail boxes offset and size. */ static inline void mlxsw_i2c_convert_mbox(struct mlxsw_i2c *mlxsw_i2c, u8 *buf) { u32 tmp; /* Local in/out mailboxes: 20 bits for offset, 12 for size */ tmp = be32_to_cpup((__be32 *) buf); mlxsw_i2c->cmd.mb_off_in = tmp & GENMASK(MLXSW_I2C_MBOX_OFFSET_BITS - 1, 0); mlxsw_i2c->cmd.mb_size_in = (tmp & GENMASK(31, MLXSW_I2C_MBOX_OFFSET_BITS)) >> MLXSW_I2C_MBOX_OFFSET_BITS; tmp = be32_to_cpup((__be32 *) (buf + MLXSW_I2C_ADDR_WIDTH)); mlxsw_i2c->cmd.mb_off_out = tmp & GENMASK(MLXSW_I2C_MBOX_OFFSET_BITS - 1, 0); mlxsw_i2c->cmd.mb_size_out = (tmp & GENMASK(31, MLXSW_I2C_MBOX_OFFSET_BITS)) >> MLXSW_I2C_MBOX_OFFSET_BITS; } /* Routine obtains register size from mail box buffer. */ static inline int mlxsw_i2c_get_reg_size(u8 *in_mbox) { u16 tmp = be16_to_cpup((__be16 *) (in_mbox + MLXSW_I2C_TLV_HDR_SIZE)); return (tmp & 0x7ff) * 4 + MLXSW_I2C_TLV_HDR_SIZE; } /* Routine sets I2C device internal offset in the transaction buffer. */ static inline void mlxsw_i2c_set_slave_addr(u8 *buf, u32 off) { __be32 *val = (__be32 *) buf; *val = htonl(off); } /* Routine waits until go bit is cleared. */ static int mlxsw_i2c_wait_go_bit(struct i2c_client *client, struct mlxsw_i2c *mlxsw_i2c, u8 *p_status) { u8 addr_buf[MLXSW_I2C_ADDR_BUF_SIZE]; u8 buf[MLXSW_I2C_READ_SEMA_SIZE]; int len = MLXSW_I2C_READ_SEMA_SIZE; struct i2c_msg read_sema[] = MLXSW_I2C_READ_MSG(client, addr_buf, buf, len); bool wait_done = false; unsigned long end; int i = 0, err; mlxsw_i2c_set_slave_addr(addr_buf, MLXSW_I2C_CIR2_OFF_STATUS); end = jiffies + msecs_to_jiffies(MLXSW_I2C_TIMEOUT_MSECS); do { u32 ctrl; err = i2c_transfer(client->adapter, read_sema, ARRAY_SIZE(read_sema)); ctrl = be32_to_cpu(*(__be32 *) buf); if (err == ARRAY_SIZE(read_sema)) { if (!(ctrl & MLXSW_I2C_GO_BIT)) { wait_done = true; *p_status = ctrl >> MLXSW_I2C_CIR_CTRL_STATUS_SHIFT; break; } } cond_resched(); } while ((time_before(jiffies, end)) || (i++ < MLXSW_I2C_RETRY)); if (wait_done) { if (*p_status) err = -EIO; } else { return -ETIMEDOUT; } return err > 0 ? 0 : err; } /* Routine posts a command to ASIC though mail box. */ static int mlxsw_i2c_write_cmd(struct i2c_client *client, struct mlxsw_i2c *mlxsw_i2c, int immediate) { __be32 push_cmd_buf[MLXSW_I2C_PUSH_CMD_SIZE / 4] = { 0, cpu_to_be32(MLXSW_I2C_PUSH_IMM_CMD) }; __be32 prep_cmd_buf[MLXSW_I2C_PREP_SIZE / 4] = { 0, 0, 0, 0, 0, 0, cpu_to_be32(client->adapter->nr & 0xffff), cpu_to_be32(MLXSW_I2C_SET_IMM_CMD) }; struct i2c_msg push_cmd = MLXSW_I2C_WRITE_MSG(client, push_cmd_buf, MLXSW_I2C_PUSH_CMD_SIZE); struct i2c_msg prep_cmd = MLXSW_I2C_WRITE_MSG(client, prep_cmd_buf, MLXSW_I2C_PREP_SIZE); int err; if (!immediate) { push_cmd_buf[1] = cpu_to_be32(MLXSW_I2C_PUSH_CMD); prep_cmd_buf[7] = cpu_to_be32(MLXSW_I2C_SET_CMD); } mlxsw_i2c_set_slave_addr((u8 *)prep_cmd_buf, MLXSW_I2C_CIR2_BASE); mlxsw_i2c_set_slave_addr((u8 *)push_cmd_buf, MLXSW_I2C_CIR2_OFF_STATUS); /* Prepare Command Interface Register for transaction */ err = i2c_transfer(client->adapter, &prep_cmd, 1); if (err < 0) return err; else if (err != 1) return -EIO; /* Write out Command Interface Register GO bit to push transaction */ err = i2c_transfer(client->adapter, &push_cmd, 1); if (err < 0) return err; else if (err != 1) return -EIO; return 0; } /* Routine obtains mail box offsets from ASIC register space. */ static int mlxsw_i2c_get_mbox(struct i2c_client *client, struct mlxsw_i2c *mlxsw_i2c) { u8 addr_buf[MLXSW_I2C_ADDR_BUF_SIZE]; u8 buf[MLXSW_I2C_MBOX_SIZE]; struct i2c_msg mbox_cmd[] = MLXSW_I2C_READ_MSG(client, addr_buf, buf, MLXSW_I2C_MBOX_SIZE); int err; /* Read mail boxes offsets. */ mlxsw_i2c_set_slave_addr(addr_buf, MLXSW_I2C_CIR2_BASE); err = i2c_transfer(client->adapter, mbox_cmd, 2); if (err != 2) { dev_err(&client->dev, "Could not obtain mail boxes\n"); if (!err) return -EIO; else return err; } /* Convert mail boxes. */ mlxsw_i2c_convert_mbox(mlxsw_i2c, &buf[MLXSW_I2C_MBOX_OUT_PARAM_OFF]); return err; } /* Routine sends I2C write transaction to ASIC device. */ static int mlxsw_i2c_write(struct device *dev, size_t in_mbox_size, u8 *in_mbox, int num, u8 *p_status) { struct i2c_client *client = to_i2c_client(dev); struct mlxsw_i2c *mlxsw_i2c = i2c_get_clientdata(client); unsigned long timeout = msecs_to_jiffies(MLXSW_I2C_TIMEOUT_MSECS); u8 tran_buf[MLXSW_I2C_MAX_BUFF_SIZE + MLXSW_I2C_ADDR_BUF_SIZE]; int off = mlxsw_i2c->cmd.mb_off_in, chunk_size, i, j; unsigned long end; struct i2c_msg write_tran = MLXSW_I2C_WRITE_MSG(client, tran_buf, MLXSW_I2C_PUSH_CMD_SIZE); int err; for (i = 0; i < num; i++) { chunk_size = (in_mbox_size > MLXSW_I2C_BLK_MAX) ? MLXSW_I2C_BLK_MAX : in_mbox_size; write_tran.len = MLXSW_I2C_ADDR_WIDTH + chunk_size; mlxsw_i2c_set_slave_addr(tran_buf, off); memcpy(&tran_buf[MLXSW_I2C_ADDR_BUF_SIZE], in_mbox + chunk_size * i, chunk_size); j = 0; end = jiffies + timeout; do { err = i2c_transfer(client->adapter, &write_tran, 1); if (err == 1) break; cond_resched(); } while ((time_before(jiffies, end)) || (j++ < MLXSW_I2C_RETRY)); if (err != 1) { if (!err) err = -EIO; return err; } off += chunk_size; in_mbox_size -= chunk_size; } /* Prepare and write out Command Interface Register for transaction. */ err = mlxsw_i2c_write_cmd(client, mlxsw_i2c, 0); if (err) { dev_err(&client->dev, "Could not start transaction"); return -EIO; } /* Wait until go bit is cleared. */ err = mlxsw_i2c_wait_go_bit(client, mlxsw_i2c, p_status); if (err) { dev_err(&client->dev, "HW semaphore is not released"); return err; } /* Validate transaction completion status. */ if (*p_status) { dev_err(&client->dev, "Bad transaction completion status %x\n", *p_status); return -EIO; } return err > 0 ? 0 : err; } /* Routine executes I2C command. */ static int mlxsw_i2c_cmd(struct device *dev, size_t in_mbox_size, u8 *in_mbox, size_t out_mbox_size, u8 *out_mbox, u8 *status) { struct i2c_client *client = to_i2c_client(dev); struct mlxsw_i2c *mlxsw_i2c = i2c_get_clientdata(client); unsigned long timeout = msecs_to_jiffies(MLXSW_I2C_TIMEOUT_MSECS); u8 tran_buf[MLXSW_I2C_ADDR_BUF_SIZE]; int num, chunk_size, reg_size, i, j; int off = mlxsw_i2c->cmd.mb_off_out; unsigned long end; struct i2c_msg read_tran[] = MLXSW_I2C_READ_MSG(client, tran_buf, NULL, 0); int err; WARN_ON(in_mbox_size % sizeof(u32) || out_mbox_size % sizeof(u32)); reg_size = mlxsw_i2c_get_reg_size(in_mbox); num = reg_size / MLXSW_I2C_BLK_MAX; if (reg_size % MLXSW_I2C_BLK_MAX) num++; if (mutex_lock_interruptible(&mlxsw_i2c->cmd.lock) < 0) { dev_err(&client->dev, "Could not acquire lock"); return -EINVAL; } err = mlxsw_i2c_write(dev, reg_size, in_mbox, num, status); if (err) goto cmd_fail; /* No out mailbox is case of write transaction. */ if (!out_mbox) { mutex_unlock(&mlxsw_i2c->cmd.lock); return 0; } /* Send read transaction to get output mailbox content. */ read_tran[1].buf = out_mbox; for (i = 0; i < num; i++) { chunk_size = (reg_size > MLXSW_I2C_BLK_MAX) ? MLXSW_I2C_BLK_MAX : reg_size; read_tran[1].len = chunk_size; mlxsw_i2c_set_slave_addr(tran_buf, off); j = 0; end = jiffies + timeout; do { err = i2c_transfer(client->adapter, read_tran, ARRAY_SIZE(read_tran)); if (err == ARRAY_SIZE(read_tran)) break; cond_resched(); } while ((time_before(jiffies, end)) || (j++ < MLXSW_I2C_RETRY)); if (err != ARRAY_SIZE(read_tran)) { if (!err) err = -EIO; goto cmd_fail; } off += chunk_size; reg_size -= chunk_size; read_tran[1].buf += chunk_size; } mutex_unlock(&mlxsw_i2c->cmd.lock); return 0; cmd_fail: mutex_unlock(&mlxsw_i2c->cmd.lock); return err; } static int mlxsw_i2c_cmd_exec(void *bus_priv, u16 opcode, u8 opcode_mod, u32 in_mod, bool out_mbox_direct, char *in_mbox, size_t in_mbox_size, char *out_mbox, size_t out_mbox_size, u8 *status) { struct mlxsw_i2c *mlxsw_i2c = bus_priv; return mlxsw_i2c_cmd(mlxsw_i2c->dev, in_mbox_size, in_mbox, out_mbox_size, out_mbox, status); } static bool mlxsw_i2c_skb_transmit_busy(void *bus_priv, const struct mlxsw_tx_info *tx_info) { return false; } static int mlxsw_i2c_skb_transmit(void *bus_priv, struct sk_buff *skb, const struct mlxsw_tx_info *tx_info) { return 0; } static int mlxsw_i2c_init(void *bus_priv, struct mlxsw_core *mlxsw_core, const struct mlxsw_config_profile *profile, struct mlxsw_res *resources) { struct mlxsw_i2c *mlxsw_i2c = bus_priv; mlxsw_i2c->core = mlxsw_core; return 0; } static void mlxsw_i2c_fini(void *bus_priv) { struct mlxsw_i2c *mlxsw_i2c = bus_priv; mlxsw_i2c->core = NULL; } static const struct mlxsw_bus mlxsw_i2c_bus = { .kind = "i2c", .init = mlxsw_i2c_init, .fini = mlxsw_i2c_fini, .skb_transmit_busy = mlxsw_i2c_skb_transmit_busy, .skb_transmit = mlxsw_i2c_skb_transmit, .cmd_exec = mlxsw_i2c_cmd_exec, }; static int mlxsw_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct mlxsw_i2c *mlxsw_i2c; u8 status; int err; mlxsw_i2c = devm_kzalloc(&client->dev, sizeof(*mlxsw_i2c), GFP_KERNEL); if (!mlxsw_i2c) return -ENOMEM; i2c_set_clientdata(client, mlxsw_i2c); mutex_init(&mlxsw_i2c->cmd.lock); /* In order to use mailboxes through the i2c, special area is reserved * on the i2c address space that can be used for input and output * mailboxes. Such mailboxes are called local mailboxes. When using a * local mailbox, software should specify 0 as the Input/Output * parameters. The location of the Local Mailbox addresses on the i2c * space can be retrieved through the QUERY_FW command. * For this purpose QUERY_FW is to be issued with opcode modifier equal * 0x01. For such command the output parameter is an immediate value. * Here QUERY_FW command is invoked for ASIC probing and for getting * local mailboxes addresses from immedate output parameters. */ /* Prepare and write out Command Interface Register for transaction */ err = mlxsw_i2c_write_cmd(client, mlxsw_i2c, 1); if (err) { dev_err(&client->dev, "Could not start transaction"); goto errout; } /* Wait until go bit is cleared. */ err = mlxsw_i2c_wait_go_bit(client, mlxsw_i2c, &status); if (err) { dev_err(&client->dev, "HW semaphore is not released"); goto errout; } /* Validate transaction completion status. */ if (status) { dev_err(&client->dev, "Bad transaction completion status %x\n", status); err = -EIO; goto errout; } /* Get mailbox offsets. */ err = mlxsw_i2c_get_mbox(client, mlxsw_i2c); if (err < 0) { dev_err(&client->dev, "Fail to get mailboxes\n"); goto errout; } dev_info(&client->dev, "%s mb size=%x off=0x%08x out mb size=%x off=0x%08x\n", id->name, mlxsw_i2c->cmd.mb_size_in, mlxsw_i2c->cmd.mb_off_in, mlxsw_i2c->cmd.mb_size_out, mlxsw_i2c->cmd.mb_off_out); /* Register device bus. */ mlxsw_i2c->bus_info.device_kind = id->name; mlxsw_i2c->bus_info.device_name = client->name; mlxsw_i2c->bus_info.dev = &client->dev; mlxsw_i2c->dev = &client->dev; err = mlxsw_core_bus_device_register(&mlxsw_i2c->bus_info, &mlxsw_i2c_bus, mlxsw_i2c); if (err) { dev_err(&client->dev, "Fail to register core bus\n"); return err; } return 0; errout: i2c_set_clientdata(client, NULL); return err; } static int mlxsw_i2c_remove(struct i2c_client *client) { struct mlxsw_i2c *mlxsw_i2c = i2c_get_clientdata(client); mlxsw_core_bus_device_unregister(mlxsw_i2c->core); mutex_destroy(&mlxsw_i2c->cmd.lock); return 0; } int mlxsw_i2c_driver_register(struct i2c_driver *i2c_driver) { i2c_driver->probe = mlxsw_i2c_probe; i2c_driver->remove = mlxsw_i2c_remove; return i2c_add_driver(i2c_driver); } EXPORT_SYMBOL(mlxsw_i2c_driver_register); void mlxsw_i2c_driver_unregister(struct i2c_driver *i2c_driver) { i2c_del_driver(i2c_driver); } EXPORT_SYMBOL(mlxsw_i2c_driver_unregister); MODULE_AUTHOR("Vadim Pasternak "); MODULE_DESCRIPTION("Mellanox switch I2C interface driver"); MODULE_LICENSE("Dual BSD/GPL");