blob: c0dcfa05b0771589631e1c20fa68801622abb6c4 [file] [log] [blame]
/*
* 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 +
MLXSW_I2C_BLK_MAX * 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 0;
}
/* 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");