u-boot/drivers/i2c/iproc_i2c.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2018 Broadcom
*
*/
#include <asm/global_data.h>
#include <asm/io.h>
#include <common.h>
#include <config.h>
#include <dm.h>
#include "errno.h"
#include <i2c.h>
#include "iproc_i2c.h"
DECLARE_GLOBAL_DATA_PTR;
struct iproc_i2c_regs {
u32 cfg_reg;
u32 timg_cfg;
u32 addr_reg;
u32 mstr_fifo_ctrl;
u32 slv_fifo_ctrl;
u32 bitbng_ctrl;
u32 blnks[6]; /* Not to be used */
u32 mstr_cmd;
u32 slv_cmd;
u32 evt_en;
u32 evt_sts;
u32 mstr_datawr;
u32 mstr_datard;
u32 slv_datawr;
u32 slv_datard;
};
struct iproc_i2c {
struct iproc_i2c_regs __iomem *base; /* register base */
int bus_speed;
int i2c_init_done;
};
/* Function to read a value from specified register. */
static unsigned int iproc_i2c_reg_read(u32 *reg_addr)
{
unsigned int val;
val = readl((void *)(reg_addr));
return cpu_to_le32(val);
}
/* Function to write a value ('val') in to a specified register. */
static int iproc_i2c_reg_write(u32 *reg_addr, unsigned int val)
{
val = cpu_to_le32(val);
writel(val, (void *)(reg_addr));
return 0;
}
#if defined(DEBUG)
static int iproc_dump_i2c_regs(struct iproc_i2c *bus_prvdata)
{
struct iproc_i2c_regs *base = bus_prvdata->base;
unsigned int regval;
debug("\n----------------------------------------------\n");
debug("%s: Dumping SMBus registers...\n", __func__);
regval = iproc_i2c_reg_read(&base->cfg_reg);
debug("CCB_SMB_CFG_REG=0x%08X\n", regval);
regval = iproc_i2c_reg_read(&base->timg_cfg);
debug("CCB_SMB_TIMGCFG_REG=0x%08X\n", regval);
regval = iproc_i2c_reg_read(&base->addr_reg);
debug("CCB_SMB_ADDR_REG=0x%08X\n", regval);
regval = iproc_i2c_reg_read(&base->mstr_fifo_ctrl);
debug("CCB_SMB_MSTRFIFOCTL_REG=0x%08X\n", regval);
regval = iproc_i2c_reg_read(&base->slv_fifo_ctrl);
debug("CCB_SMB_SLVFIFOCTL_REG=0x%08X\n", regval);
regval = iproc_i2c_reg_read(&base->bitbng_ctrl);
debug("CCB_SMB_BITBANGCTL_REG=0x%08X\n", regval);
regval = iproc_i2c_reg_read(&base->mstr_cmd);
debug("CCB_SMB_MSTRCMD_REG=0x%08X\n", regval);
regval = iproc_i2c_reg_read(&base->slv_cmd);
debug("CCB_SMB_SLVCMD_REG=0x%08X\n", regval);
regval = iproc_i2c_reg_read(&base->evt_en);
debug("CCB_SMB_EVTEN_REG=0x%08X\n", regval);
regval = iproc_i2c_reg_read(&base->evt_sts);
debug("CCB_SMB_EVTSTS_REG=0x%08X\n", regval);
regval = iproc_i2c_reg_read(&base->mstr_datawr);
debug("CCB_SMB_MSTRDATAWR_REG=0x%08X\n", regval);
regval = iproc_i2c_reg_read(&base->mstr_datard);
debug("CCB_SMB_MSTRDATARD_REG=0x%08X\n", regval);
regval = iproc_i2c_reg_read(&base->slv_datawr);
debug("CCB_SMB_SLVDATAWR_REG=0x%08X\n", regval);
regval = iproc_i2c_reg_read(&base->slv_datard);
debug("CCB_SMB_SLVDATARD_REG=0x%08X\n", regval);
debug("----------------------------------------------\n\n");
return 0;
}
#else
static int iproc_dump_i2c_regs(struct iproc_i2c *bus_prvdata)
{
return 0;
}
#endif
/*
* Function to ensure that the previous transaction was completed before
* initiating a new transaction. It can also be used in polling mode to
* check status of completion of a command
*/
static int iproc_i2c_startbusy_wait(struct iproc_i2c *bus_prvdata)
{
struct iproc_i2c_regs *base = bus_prvdata->base;
unsigned int regval;
regval = iproc_i2c_reg_read(&base->mstr_cmd);
/* Check if an operation is in progress. During probe it won't be.
* But when shutdown/remove was called we want to make sure that
* the transaction in progress completed
*/
if (regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK) {
unsigned int i = 0;
do {
mdelay(10);
i++;
regval = iproc_i2c_reg_read(&base->mstr_cmd);
/* If start-busy bit cleared, exit the loop */
} while ((regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK) &&
(i < IPROC_SMB_MAX_RETRIES));
if (i >= IPROC_SMB_MAX_RETRIES) {
pr_err("%s: START_BUSY bit didn't clear, exiting\n",
__func__);
return -ETIMEDOUT;
}
}
return 0;
}
/*
* This function set clock frequency for SMBus block. As per hardware
* engineering, the clock frequency can be changed dynamically.
*/
static int iproc_i2c_set_clk_freq(struct iproc_i2c *bus_prvdata)
{
struct iproc_i2c_regs *base = bus_prvdata->base;
unsigned int regval;
regval = iproc_i2c_reg_read(&base->timg_cfg);
switch (bus_prvdata->bus_speed) {
case I2C_SPEED_STANDARD_RATE:
regval &= ~CCB_SMB_TIMGCFG_MODE400_MASK;
break;
case I2C_SPEED_FAST_RATE:
regval |= CCB_SMB_TIMGCFG_MODE400_MASK;
break;
default:
return -EINVAL;
}
iproc_i2c_reg_write(&base->timg_cfg, regval);
return 0;
}
static int iproc_i2c_init(struct udevice *bus)
{
struct iproc_i2c *bus_prvdata = dev_get_priv(bus);
struct iproc_i2c_regs *base = bus_prvdata->base;
unsigned int regval;
debug("\nEntering %s\n", __func__);
/* Put controller in reset */
regval = iproc_i2c_reg_read(&base->cfg_reg);
regval |= CCB_SMB_CFG_RST_MASK;
regval &= ~CCB_SMB_CFG_SMBEN_MASK;
iproc_i2c_reg_write(&base->cfg_reg, regval);
/* Wait 100 usec as per spec */
udelay(100);
/* bring controller out of reset */
regval &= ~CCB_SMB_CFG_RST_MASK;
iproc_i2c_reg_write(&base->cfg_reg, regval);
/* Flush Tx, Rx FIFOs. Note we are setting the Rx FIFO threshold to 0.
* May be OK since we are setting RX_EVENT and RX_FIFO_FULL interrupts
*/
regval = CCB_SMB_MSTRRXFIFOFLSH_MASK | CCB_SMB_MSTRTXFIFOFLSH_MASK;
iproc_i2c_reg_write(&base->mstr_fifo_ctrl, regval);
/* Enable SMbus block. Note, we are setting MASTER_RETRY_COUNT to zero
* since there will be only one master
*/
regval = iproc_i2c_reg_read(&base->cfg_reg);
regval |= CCB_SMB_CFG_SMBEN_MASK;
iproc_i2c_reg_write(&base->cfg_reg, regval);
/* Set default clock frequency */
iproc_i2c_set_clk_freq(bus_prvdata);
/* Disable intrs */
iproc_i2c_reg_write(&base->evt_en, 0);
/* Clear intrs (W1TC) */
regval = iproc_i2c_reg_read(&base->evt_sts);
iproc_i2c_reg_write(&base->evt_sts, regval);
bus_prvdata->i2c_init_done = 1;
iproc_dump_i2c_regs(bus_prvdata);
debug("%s: Init successful\n", __func__);
return 0;
}
/*
* This function copies data to SMBus's Tx FIFO. Valid for write transactions
* only
*
* base_addr: Mapped address of this SMBus instance
* dev_addr: SMBus (I2C) device address. We are assuming 7-bit addresses
* initially
* info: Data to copy in to Tx FIFO. For read commands, the size should be
* set to zero by the caller
*
*/
static void iproc_i2c_write_trans_data(struct iproc_i2c *bus_prvdata,
unsigned short dev_addr,
struct iproc_xact_info *info)
{
struct iproc_i2c_regs *base = bus_prvdata->base;
unsigned int regval;
unsigned int i;
unsigned int num_data_bytes = 0;
debug("%s: dev_addr=0x%X cmd_valid=%d cmd=0x%02x size=%u proto=%d buf[] %x\n",
__func__, dev_addr, info->cmd_valid,
info->command, info->size, info->smb_proto, info->data[0]);
/* Write SMBus device address first */
/* Note, we are assuming 7-bit addresses for now. For 10-bit addresses,
* we may have one more write to send the upper 3 bits of 10-bit addr
*/
iproc_i2c_reg_write(&base->mstr_datawr, dev_addr);
/* If the protocol needs command code, copy it */
if (info->cmd_valid)
iproc_i2c_reg_write(&base->mstr_datawr, info->command);
/* Depending on the SMBus protocol, we need to write additional
* transaction data in to Tx FIFO. Refer to section 5.5 of SMBus
* spec for sequence for a transaction
*/
switch (info->smb_proto) {
case SMBUS_PROT_RECV_BYTE:
/* No additional data to be written */
num_data_bytes = 0;
break;
case SMBUS_PROT_SEND_BYTE:
num_data_bytes = info->size;
break;
case SMBUS_PROT_RD_BYTE:
case SMBUS_PROT_RD_WORD:
case SMBUS_PROT_BLK_RD:
/* Write slave address with R/W~ set (bit #0) */
iproc_i2c_reg_write(&base->mstr_datawr,
dev_addr | 0x1);
num_data_bytes = 0;
break;
case SMBUS_PROT_BLK_WR_BLK_RD_PROC_CALL:
iproc_i2c_reg_write(&base->mstr_datawr,
dev_addr | 0x1 |
CCB_SMB_MSTRWRSTS_MASK);
num_data_bytes = 0;
break;
case SMBUS_PROT_WR_BYTE:
case SMBUS_PROT_WR_WORD:
/* No additional bytes to be written.
* Data portion is written in the
* 'for' loop below
*/
num_data_bytes = info->size;
break;
case SMBUS_PROT_BLK_WR:
/* 3rd byte is byte count */
iproc_i2c_reg_write(&base->mstr_datawr, info->size);
num_data_bytes = info->size;
break;
default:
return;
}
/* Copy actual data from caller, next. In general, for reads,
* no data is copied
*/
for (i = 0; num_data_bytes; --num_data_bytes, i++) {
/* For the last byte, set MASTER_WR_STATUS bit */
regval = (num_data_bytes == 1) ?
info->data[i] | CCB_SMB_MSTRWRSTS_MASK :
info->data[i];
iproc_i2c_reg_write(&base->mstr_datawr, regval);
}
}
static int iproc_i2c_data_send(struct iproc_i2c *bus_prvdata,
unsigned short addr,
struct iproc_xact_info *info)
{
struct iproc_i2c_regs *base = bus_prvdata->base;
int rc, retry = 3;
unsigned int regval;
/* Make sure the previous transaction completed */
rc = iproc_i2c_startbusy_wait(bus_prvdata);
if (rc < 0) {
pr_err("%s: Send: bus is busy, exiting\n", __func__);
return rc;
}
/* Write transaction bytes to Tx FIFO */
iproc_i2c_write_trans_data(bus_prvdata, addr, info);
/* Program master command register (0x30) with protocol type and set
* start_busy_command bit to initiate the write transaction
*/
regval = (info->smb_proto << CCB_SMB_MSTRSMBUSPROTO_SHIFT) |
CCB_SMB_MSTRSTARTBUSYCMD_MASK;
iproc_i2c_reg_write(&base->mstr_cmd, regval);
/* Check for Master status */
regval = iproc_i2c_reg_read(&base->mstr_cmd);
while (regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK) {
mdelay(10);
if (retry-- <= 0)
break;
regval = iproc_i2c_reg_read(&base->mstr_cmd);
}
/* If start_busy bit cleared, check if there are any errors */
if (!(regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK)) {
/* start_busy bit cleared, check master_status field now */
regval &= CCB_SMB_MSTRSTS_MASK;
regval >>= CCB_SMB_MSTRSTS_SHIFT;
if (regval != MSTR_STS_XACT_SUCCESS) {
/* Error We can flush Tx FIFO here */
pr_err("%s: ERROR: Error in transaction %u, exiting\n",
__func__, regval);
return -EREMOTEIO;
}
}
return 0;
}
static int iproc_i2c_data_recv(struct iproc_i2c *bus_prvdata,
unsigned short addr,
struct iproc_xact_info *info,
unsigned int *num_bytes_read)
{
struct iproc_i2c_regs *base = bus_prvdata->base;
int rc, retry = 3;
unsigned int regval;
/* Make sure the previous transaction completed */
rc = iproc_i2c_startbusy_wait(bus_prvdata);
if (rc < 0) {
pr_err("%s: Receive: Bus is busy, exiting\n", __func__);
return rc;
}
/* Program all transaction bytes into master Tx FIFO */
iproc_i2c_write_trans_data(bus_prvdata, addr, info);
/* Program master command register (0x30) with protocol type and set
* start_busy_command bit to initiate the write transaction
*/
regval = (info->smb_proto << CCB_SMB_MSTRSMBUSPROTO_SHIFT) |
CCB_SMB_MSTRSTARTBUSYCMD_MASK | info->size;
iproc_i2c_reg_write(&base->mstr_cmd, regval);
/* Check for Master status */
regval = iproc_i2c_reg_read(&base->mstr_cmd);
while (regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK) {
udelay(1000);
if (retry-- <= 0)
break;
regval = iproc_i2c_reg_read(&base->mstr_cmd);
}
/* If start_busy bit cleared, check if there are any errors */
if (!(regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK)) {
/* start_busy bit cleared, check master_status field now */
regval &= CCB_SMB_MSTRSTS_MASK;
regval >>= CCB_SMB_MSTRSTS_SHIFT;
if (regval != MSTR_STS_XACT_SUCCESS) {
/* We can flush Tx FIFO here */
pr_err("%s: Error in transaction %d, exiting\n",
__func__, regval);
return -EREMOTEIO;
}
}
/* Read received byte(s), after TX out address etc */
regval = iproc_i2c_reg_read(&base->mstr_datard);
/* For block read, protocol (hw) returns byte count,
* as the first byte
*/
if (info->smb_proto == SMBUS_PROT_BLK_RD) {
int i;
*num_bytes_read = regval & CCB_SMB_MSTRRDDATA_MASK;
/* Limit to reading a max of 32 bytes only; just a safeguard.
* If # bytes read is a number > 32, check transaction set up,
* and contact hw engg. Assumption: PEC is disabled
*/
for (i = 0;
(i < *num_bytes_read) && (i < I2C_SMBUS_BLOCK_MAX);
i++) {
/* Read Rx FIFO for data bytes */
regval = iproc_i2c_reg_read(&base->mstr_datard);
info->data[i] = regval & CCB_SMB_MSTRRDDATA_MASK;
}
} else {
/* 1 Byte data */
*info->data = regval & CCB_SMB_MSTRRDDATA_MASK;
*num_bytes_read = 1;
}
return 0;
}
static int i2c_write_byte(struct iproc_i2c *bus_prvdata,
u8 devaddr, u8 regoffset, u8 value)
{
int rc;
struct iproc_xact_info info;
devaddr <<= 1;
info.cmd_valid = 1;
info.command = (unsigned char)regoffset;
info.data = &value;
info.size = 1;
info.flags = 0;
info.smb_proto = SMBUS_PROT_WR_BYTE;
/* Refer to i2c_smbus_write_byte params passed. */
rc = iproc_i2c_data_send(bus_prvdata, devaddr, &info);
if (rc < 0) {
pr_err("%s: %s error accessing device 0x%X\n",
__func__, "Write", devaddr);
return -EREMOTEIO;
}
return 0;
}
int i2c_write(struct udevice *bus,
uchar chip, uint regaddr, int alen, uchar *buffer, int len)
{
struct iproc_i2c *bus_prvdata = dev_get_priv(bus);
int i, data_len;
u8 *data;
if (len > 256) {
pr_err("I2C write: address out of range\n");
return 1;
}
if (len < 1) {
pr_err("I2C write: Need offset addr and value\n");
return 1;
}
/* buffer contains offset addr followed by value to be written */
regaddr = buffer[0];
data = &buffer[1];
data_len = len - 1;
for (i = 0; i < data_len; i++) {
if (i2c_write_byte(bus_prvdata, chip, regaddr + i, data[i])) {
pr_err("I2C write (%d): I/O error\n", i);
iproc_i2c_init(bus);
return 1;
}
}
return 0;
}
static int i2c_read_byte(struct iproc_i2c *bus_prvdata,
u8 devaddr, u8 regoffset, u8 *value)
{
int rc;
struct iproc_xact_info info;
unsigned int num_bytes_read = 0;
devaddr <<= 1;
info.cmd_valid = 1;
info.command = (unsigned char)regoffset;
info.data = value;
info.size = 1;
info.flags = 0;
info.smb_proto = SMBUS_PROT_RD_BYTE;
/* Refer to i2c_smbus_read_byte for params passed. */
rc = iproc_i2c_data_recv(bus_prvdata, devaddr, &info, &num_bytes_read);
if (rc < 0) {
pr_err("%s: %s error accessing device 0x%X\n",
__func__, "Read", devaddr);
return -EREMOTEIO;
}
return 0;
}
int i2c_read(struct udevice *bus,
uchar chip, uint addr, int alen, uchar *buffer, int len)
{
struct iproc_i2c *bus_prvdata = dev_get_priv(bus);
int i;
if (len > 256) {
pr_err("I2C read: address out of range\n");
return 1;
}
for (i = 0; i < len; i++) {
if (i2c_read_byte(bus_prvdata, chip, addr + i, &buffer[i])) {
pr_err("I2C read: I/O error\n");
iproc_i2c_init(bus);
return 1;
}
}
return 0;
}
static int iproc_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
{
int ret = 0;
debug("%s: %d messages\n", __func__, nmsgs);
for (; nmsgs > 0; nmsgs--, msg++) {
if (msg->flags & I2C_M_RD)
ret = i2c_read(bus, msg->addr, 0, 0,
msg->buf, msg->len);
else
ret = i2c_write(bus, msg->addr, 0, 0,
msg->buf, msg->len);
}
return ret;
}
static int iproc_i2c_probe_chip(struct udevice *bus, uint chip_addr,
uint chip_flags)
{
struct iproc_i2c *bus_prvdata = dev_get_priv(bus);
struct iproc_i2c_regs *base = bus_prvdata->base;
u32 regval;
debug("\n%s: Entering chip probe\n", __func__);
/* Init internal regs, disable intrs (and then clear intrs), set fifo
* thresholds, etc.
*/
if (!bus_prvdata->i2c_init_done)
iproc_i2c_init(bus);
regval = (chip_addr << 1);
iproc_i2c_reg_write(&base->mstr_datawr, regval);
regval = ((SMBUS_PROT_QUICK_CMD << CCB_SMB_MSTRSMBUSPROTO_SHIFT) |
(1 << CCB_SMB_MSTRSTARTBUSYCMD_SHIFT));
iproc_i2c_reg_write(&base->mstr_cmd, regval);
do {
udelay(100);
regval = iproc_i2c_reg_read(&base->mstr_cmd);
regval &= CCB_SMB_MSTRSTARTBUSYCMD_MASK;
} while (regval);
regval = iproc_i2c_reg_read(&base->mstr_cmd);
if ((regval & CCB_SMB_MSTRSTS_MASK) != 0)
return -1;
iproc_dump_i2c_regs(bus_prvdata);
debug("%s: chip probe successful\n", __func__);
return 0;
}
static int iproc_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
{
struct iproc_i2c *bus_prvdata = dev_get_priv(bus);
bus_prvdata->bus_speed = speed;
return iproc_i2c_set_clk_freq(bus_prvdata);
}
/**
* i2c_get_bus_speed - get i2c bus speed
*
* This function returns the speed of operation in Hz
*/
int iproc_i2c_get_bus_speed(struct udevice *bus)
{
struct iproc_i2c *bus_prvdata = dev_get_priv(bus);
struct iproc_i2c_regs *base = bus_prvdata->base;
unsigned int regval;
int ret = 0;
regval = iproc_i2c_reg_read(&base->timg_cfg);
regval = (regval & CCB_SMB_TIMGCFG_MODE400_MASK) >>
CCB_SMB_TIMGCFG_MODE400_SHIFT;
switch (regval) {
case 0:
ret = I2C_SPEED_STANDARD_RATE;
break;
case 1:
ret = I2C_SPEED_FAST_RATE;
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
static int iproc_i2c_probe(struct udevice *bus)
{
return iproc_i2c_init(bus);
}
static int iproc_i2c_of_to_plat(struct udevice *bus)
{
struct iproc_i2c *bus_prvdata = dev_get_priv(bus);
int node = dev_of_offset(bus);
const void *blob = gd->fdt_blob;
bus_prvdata->base = map_physmem(dev_read_addr(bus),
sizeof(void *),
MAP_NOCACHE);
bus_prvdata->bus_speed =
fdtdec_get_int(blob, node, "bus-frequency",
I2C_SPEED_STANDARD_RATE);
return 0;
}
static const struct dm_i2c_ops iproc_i2c_ops = {
.xfer = iproc_i2c_xfer,
.probe_chip = iproc_i2c_probe_chip,
.set_bus_speed = iproc_i2c_set_bus_speed,
.get_bus_speed = iproc_i2c_get_bus_speed,
};
static const struct udevice_id iproc_i2c_ids[] = {
{ .compatible = "brcm,iproc-i2c" },
{ }
};
U_BOOT_DRIVER(iproc_i2c) = {
.name = "iproc_i2c",
.id = UCLASS_I2C,
.of_match = iproc_i2c_ids,
.of_to_plat = iproc_i2c_of_to_plat,
.probe = iproc_i2c_probe,
.priv_auto = sizeof(struct iproc_i2c),
.ops = &iproc_i2c_ops,
.flags = DM_FLAG_PRE_RELOC,
};