diff options
Diffstat (limited to 'drivers/net/ethernet/mellanox/mlxsw/i2c.c')
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlxsw/i2c.c | 582 |
1 files changed, 582 insertions, 0 deletions
diff --git a/drivers/net/ethernet/mellanox/mlxsw/i2c.c b/drivers/net/ethernet/mellanox/mlxsw/i2c.c new file mode 100644 index 000000000000..e50c8db2602a --- /dev/null +++ b/drivers/net/ethernet/mellanox/mlxsw/i2c.c @@ -0,0 +1,582 @@ +/* + * drivers/net/ethernet/mellanox/mlxsw/i2c.c + * Copyright (c) 2016 Mellanox Technologies. All rights reserved. + * Copyright (c) 2016 Vadim Pasternak <vadimp@mellanox.com> + * + * 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 <linux/err.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/jiffies.h> +#include <linux/kernel.h> +#include <linux/mutex.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/slab.h> + +#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 <vadimp@mellanox.com>"); +MODULE_DESCRIPTION("Mellanox switch I2C interface driver"); +MODULE_LICENSE("Dual BSD/GPL"); |