/*
* (C) Copyright 2009-2010
* Nokia Siemens Networks, [email protected]
*
* Portions Copyright (C) 2010 - 2016 Cavium, Inc.
*
* This file contains the shared part of the driver for the i2c adapter in
* Cavium Networks' OCTEON processors and ThunderX SOCs.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include "i2c-octeon-core.h"
#define INITIAL_DELTA_HZ 1000000
#define TWSI_MASTER_CLK_REG_DEF_VAL 0x18
#define TWSI_MASTER_CLK_REG_OTX2_VAL 0x3
/* interrupt service routine */
irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
{
struct octeon_i2c *i2c = dev_id;
i2c->int_disable(i2c);
wake_up(&i2c->queue);
return IRQ_HANDLED;
}
static bool octeon_i2c_test_iflg(struct octeon_i2c *i2c)
{
return (octeon_i2c_ctl_read(i2c) & TWSI_CTL_IFLG);
}
/**
* octeon_i2c_wait - wait for the IFLG to be set
* @i2c: The struct octeon_i2c
*
* Returns 0 on success, otherwise a negative errno.
*/
static int octeon_i2c_wait(struct octeon_i2c *i2c)
{
long time_left;
/*
* Some chip revisions don't assert the irq in the interrupt
* controller. So we must poll for the IFLG change.
*/
if (i2c->broken_irq_mode) {
u64 end = get_jiffies_64() + i2c->adap.timeout;
while (!octeon_i2c_test_iflg(i2c) &&
time_before64(get_jiffies_64(), end))
usleep_range(I2C_OCTEON_EVENT_WAIT / 2, I2C_OCTEON_EVENT_WAIT);
return octeon_i2c_test_iflg(i2c) ? 0 : -ETIMEDOUT;
}
i2c->int_enable(i2c);
time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c),
i2c->adap.timeout);
i2c->int_disable(i2c);
if (i2c->broken_irq_check && !time_left &&
octeon_i2c_test_iflg(i2c)) {
dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
i2c->broken_irq_mode = true;
return 0;
}
if (!time_left)
return -ETIMEDOUT;
return 0;
}
static bool octeon_i2c_hlc_test_valid(struct octeon_i2c *i2c)
{
return (__raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c)) & SW_TWSI_V) == 0;
}
static void octeon_i2c_hlc_int_clear(struct octeon_i2c *i2c)
{
/* clear ST/TS events, listen for neither */
octeon_i2c_write_int(i2c, TWSI_INT_ST_INT | TWSI_INT_TS_INT);
}
/*
* Cleanup low-level state & enable high-level controller.
*/
static void octeon_i2c_hlc_enable(struct octeon_i2c *i2c)
{
int try = 0;
u64 val;
if (i2c->hlc_enabled)
return;
i2c->hlc_enabled = true;
while (1) {
val = octeon_i2c_ctl_read(i2c);
if (!(val & (TWSI_CTL_STA | TWSI_CTL_STP)))
break;
/* clear IFLG event */
if (val & TWSI_CTL_IFLG)
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
if (try++ > 100) {
pr_err("%s: giving up\n", __func__);
break;
}
/* spin until any start/stop has finished */
udelay(10);
}
octeon_i2c_ctl_write(i2c, TWSI_CTL_CE | TWSI_CTL_AAK | TWSI_CTL_ENAB);
}
static void octeon_i2c_hlc_disable(struct octeon_i2c *i2c)
{
if (!i2c->hlc_enabled)
return;
i2c->hlc_enabled = false;
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
}
/**
* octeon_i2c_hlc_wait - wait for an HLC operation to complete
* @i2c: The struct octeon_i2c
*
* Returns 0 on success, otherwise -ETIMEDOUT.
*/
static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
{
int time_left;
/*
* Some cn38xx boards don't assert the irq in the interrupt
* controller. So we must poll for the valid bit change.
*/
if (i2c->broken_irq_mode) {
u64 end = get_jiffies_64() + i2c->adap.timeout;
while (!octeon_i2c_hlc_test_valid(i2c) &&
time_before64(get_jiffies_64(), end))
usleep_range(I2C_OCTEON_EVENT_WAIT / 2, I2C_OCTEON_EVENT_WAIT);
return octeon_i2c_hlc_test_valid(i2c) ? 0 : -ETIMEDOUT;
}
i2c->hlc_int_enable(i2c);
time_left = wait_event_timeout(i2c->queue,
octeon_i2c_hlc_test_valid(i2c),
i2c->adap.timeout);
i2c->hlc_int_disable(i2c);
if (!time_left)
octeon_i2c_hlc_int_clear(i2c);
if (i2c->broken_irq_check && !time_left &&
octeon_i2c_hlc_test_valid(i2c)) {
dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
i2c->broken_irq_mode = true;
return 0;
}
if (!time_left)
return -ETIMEDOUT;
return 0;
}
static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read)
{
u8 stat;
u64 mode;
/*
* This is ugly... in HLC mode the status is not in the status register
* but in the lower 8 bits of OCTEON_REG_SW_TWSI.
*/
if (i2c->hlc_enabled)
stat = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
else
stat = octeon_i2c_stat_read(i2c);
switch (stat) {
/* Everything is fine */
case STAT_IDLE:
case STAT_AD2W_ACK:
case STAT_RXADDR_ACK:
case STAT_TXADDR_ACK:
case STAT_TXDATA_ACK:
return 0;
/* ACK allowed on pre-terminal bytes only */
case STAT_RXDATA_ACK:
if (!final_read)
return 0;
return -EIO;
/* NAK allowed on terminal byte only */
case STAT_RXDATA_NAK:
if (final_read)
return 0;
return -EIO;
/* Arbitration lost */
case STAT_LOST_ARB_38:
case STAT_LOST_ARB_68:
case STAT_LOST_ARB_78:
case STAT_LOST_ARB_B0:
return -EAGAIN;
/* Being addressed as local target, should back off & listen */
case STAT_SLAVE_60:
case STAT_SLAVE_70:
case STAT_GENDATA_ACK:
case STAT_GENDATA_NAK:
return -EOPNOTSUPP;
/* Core busy as local target */
case STAT_SLAVE_80:
case STAT_SLAVE_88:
case STAT_SLAVE_A0:
case STAT_SLAVE_A8:
case STAT_SLAVE_LOST:
case STAT_SLAVE_NAK:
case STAT_SLAVE_ACK:
return -EOPNOTSUPP;
case STAT_TXDATA_NAK:
case STAT_BUS_ERROR:
return -EIO;
case STAT_TXADDR_NAK:
case STAT_RXADDR_NAK:
case STAT_AD2W_NAK:
return -ENXIO;
case STAT_WDOG_TOUT:
mode = __raw_readq(i2c->twsi_base + OCTEON_REG_MODE(i2c));
/* Set BUS_MON_RST to reset bus monitor */
mode |= BUS_MON_RST_MASK;
octeon_i2c_writeq_flush(mode, i2c->twsi_base + OCTEON_REG_MODE(i2c));
return -EIO;
default:
dev_err(i2c->dev, "unhandled state: %d\n", stat);
return -EIO;
}
}
static int octeon_i2c_recovery(struct octeon_i2c *i2c)
{
int ret;
ret = i2c_recover_bus(&i2c->adap);
if (ret)
/* recover failed, try hardware re-init */
ret = octeon_i2c_init_lowlevel(i2c);
return ret;
}
/**
* octeon_i2c_start - send START to the bus
* @i2c: The struct octeon_i2c
*
* Returns 0 on success, otherwise a negative errno.
*/
static int octeon_i2c_start(struct octeon_i2c *i2c)
{
int ret;
u8 stat;
octeon_i2c_hlc_disable(i2c);
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STA);
ret = octeon_i2c_wait(i2c);
if (ret)
goto error;
stat = octeon_i2c_stat_read(i2c);
if (stat == STAT_START || stat == STAT_REP_START)
/* START successful, bail out */
return 0;
error:
/* START failed, try to recover */
ret = octeon_i2c_recovery(i2c);
return (ret) ? ret : -EAGAIN;
}
/* send STOP to the bus */
static void octeon_i2c_stop(struct octeon_i2c *i2c)
{
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STP);
}
/**
* octeon_i2c_read - receive data from the bus via low-level controller
* @i2c: The struct octeon_i2c
* @target: Target address
* @data: Pointer to the location to store the data
* @rlength: Length of the data
* @recv_len: flag for length byte
*
* The address is sent over the bus, then the data is read.
*
* Returns 0 on success, otherwise a negative errno.
*/
static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
u8 *data, u16 *rlength, bool recv_len)
{
int i, result, length = *rlength;
bool final_read = false;
octeon_i2c_data_write(i2c, (target << 1) | 1);
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
result = octeon_i2c_wait(i2c);
if (result)
return result;
/* address OK ? */
result = octeon_i2c_check_status(i2c, false);
if (result)
return result;
for (i = 0; i < length; i++) {
/*
* For the last byte to receive TWSI_CTL_AAK must not be set.
*
* A special case is I2C_M_RECV_LEN where we don't know the
* additional length yet. If recv_len is set we assume we're
* not reading the final byte and therefore need to set
* TWSI_CTL_AAK.
*/
if ((i + 1 == length) && !(recv_len && i == 0))
final_read = true;
/* clear iflg to allow next event */
if (final_read)
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
else
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_AAK);
result = octeon_i2c_wait(i2c);
if (result)
return result;
data[i] = octeon_i2c_data_read(i2c, &result);
if (result)
return result;
if (recv_len && i == 0) {
if (data[i] > I2C_SMBUS_BLOCK_MAX)
return -EPROTO;
length += data[i];
}
result = octeon_i2c_check_status(i2c, final_read);
if (result)
return result;
}
*rlength = length;
return 0;
}
/**
* octeon_i2c_write - send data to the bus via low-level controller
* @i2c: The struct octeon_i2c
* @target: Target address
* @data: Pointer to the data to be sent
* @length: Length of the data
*
* The address is sent over the bus, then the data.
*
* Returns 0 on success, otherwise a negative errno.
*/
static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
const u8 *data, int length)
{
int i, result;
octeon_i2c_data_write(i2c, target << 1);
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
result = octeon_i2c_wait(i2c);
if (result)
return result;
for (i = 0; i < length; i++) {
result = octeon_i2c_check_status(i2c, false);
if (result)
return result;
octeon_i2c_data_write(i2c, data[i]);
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
result = octeon_i2c_wait(i2c);
if (result)
return result;
}
return 0;
}
/* high-level-controller pure read of up to 8 bytes */
static int octeon_i2c_hlc_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
{
int i, j, ret = 0;
u64 cmd;
octeon_i2c_hlc_enable(i2c);
octeon_i2c_hlc_int_clear(i2c);
cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
/* SIZE */
cmd |= (u64)(msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT;
/* A */
cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
if (msgs[0].flags & I2C_M_TEN)
cmd |= SW_TWSI_OP_10;
else
cmd |= SW_TWSI_OP_7;
octeon_i2c_writeq_flush(cmd, i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
ret = octeon_i2c_hlc_wait(i2c);
if (ret)
goto err;
cmd = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
if ((cmd & SW_TWSI_R) == 0)
return octeon_i2c_check_status(i2c, false);
for (i = 0, j = msgs[0].len - 1; i < msgs[0].len && i < 4; i++, j--)
msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
if (msgs[0].len > 4) {
cmd = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI_EXT(i2c));
for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
}
err:
return ret;
}
/* high-level-controller pure write of up to 8 bytes */
static int octeon_i2c_hlc_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
{
int i, j, ret = 0;
u64 cmd;
octeon_i2c_hlc_enable(i2c);
octeon_i2c_hlc_int_clear(i2c);
cmd = SW_TWSI_V | SW_TWSI_SOVR;
/* SIZE */
cmd |= (u64)(msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT;
/* A */
cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
if (msgs[0].flags & I2C_M_TEN)
cmd |= SW_TWSI_OP_10;
else
cmd |= SW_TWSI_OP_7;
for (i = 0, j = msgs[0].len - 1; i < msgs[0].len && i < 4; i++, j--)
cmd |= (u64)msgs[0].buf[j] << (8 * i);
if (msgs[0].len > 4) {
u64 ext = 0;
for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
ext |= (u64)msgs[0].buf[j] << (8 * i);
octeon_i2c_writeq_flush(ext, i2c->twsi_base + OCTEON_REG_SW_TWSI_EXT(i2c));
}
octeon_i2c_writeq_flush(cmd, i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
ret = octeon_i2c_hlc_wait(i2c);
if (ret)
goto err;
cmd = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
if ((cmd & SW_TWSI_R) == 0)
return octeon_i2c_check_status(i2c, false);
err:
return ret;
}
/* high-level-controller composite write+read, msg0=addr, msg1=data */
static int octeon_i2c_hlc_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
{
int i, j, ret = 0;
u64 cmd;
octeon_i2c_hlc_enable(i2c);
cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
/* SIZE */
cmd |= (u64)(msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT;
/* A */
cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
if (msgs[0].flags & I2C_M_TEN)
cmd |= SW_TWSI_OP_10_IA;
else
cmd |= SW_TWSI_OP_7_IA;
if (msgs[0].len == 2) {
u64 ext = 0;
cmd |= SW_TWSI_EIA;
ext = (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
cmd |= (u64)msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
octeon_i2c_writeq_flush(ext, i2c->twsi_base + OCTEON_REG_SW_TWSI_EXT(i2c));
} else {
cmd |= (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
}
octeon_i2c_hlc_int_clear(i2c);
octeon_i2c_writeq_flush(cmd, i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
ret = octeon_i2c_hlc_wait(i2c);
if (ret)
goto err;
cmd = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
if ((cmd & SW_TWSI_R) == 0)
return octeon_i2c_check_status(i2c, false);
for (i = 0, j = msgs[1].len - 1; i < msgs[1].len && i < 4; i++, j--)
msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
if (msgs[1].len > 4) {
cmd = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI_EXT(i2c));
for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--)
msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
}
err:
return ret;
}
/* high-level-controller composite write+write, m[0]len<=2, m[1]len<=8 */
static int octeon_i2c_hlc_comp_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
{
bool set_ext = false;
int i, j, ret = 0;
u64 cmd, ext = 0;
octeon_i2c_hlc_enable(i2c);
cmd = SW_TWSI_V | SW_TWSI_SOVR;
/* SIZE */
cmd |= (u64)(msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT;
/* A */
cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
if (msgs[0].flags & I2C_M_TEN)
cmd |= SW_TWSI_OP_10_IA;
else
cmd |= SW_TWSI_OP_7_IA;
if (msgs[0].len == 2) {
cmd |= SW_TWSI_EIA;
ext |= (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
set_ext = true;
cmd |= (u64)msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
} else {
cmd |= (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
}
for (i = 0, j = msgs[1].len - 1; i < msgs[1].len && i < 4; i++, j--)
cmd |= (u64)msgs[1].buf[j] << (8 * i);
if (msgs[1].len > 4) {
for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--)
ext |= (u64)msgs[1].buf[j] << (8 * i);
set_ext = true;
}
if (set_ext)
octeon_i2c_writeq_flush(ext, i2c->twsi_base + OCTEON_REG_SW_TWSI_EXT(i2c));
octeon_i2c_hlc_int_clear(i2c);
octeon_i2c_writeq_flush(cmd, i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
ret = octeon_i2c_hlc_wait(i2c);
if (ret)
goto err;
cmd = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
if ((cmd & SW_TWSI_R) == 0)
return octeon_i2c_check_status(i2c, false);
err:
return ret;
}
/**
* octeon_i2c_xfer - The driver's xfer function
* @adap: Pointer to the i2c_adapter structure
* @msgs: Pointer to the messages to be processed
* @num: Length of the MSGS array
*
* Returns the number of messages processed, or a negative errno on failure.
*/
int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
struct octeon_i2c *i2c = i2c_get_adapdata(adap);
int i, ret = 0;
if (IS_LS_FREQ(i2c->twsi_freq)) {
if (num == 1) {
if (msgs[0].len > 0 && msgs[0].len <= 8) {
if (msgs[0].flags & I2C_M_RD)
ret = octeon_i2c_hlc_read(i2c, msgs);
else
ret = octeon_i2c_hlc_write(i2c, msgs);
goto out;
}
} else if (num == 2) {
if ((msgs[0].flags & I2C_M_RD) == 0 &&
(msgs[1].flags & I2C_M_RECV_LEN) == 0 &&
msgs[0].len > 0 && msgs[0].len <= 2 &&
msgs[1].len > 0 && msgs[1].len <= 8 &&
msgs[0].addr == msgs[1].addr) {
if (msgs[1].flags & I2C_M_RD)
ret = octeon_i2c_hlc_comp_read(i2c, msgs);
else
ret = octeon_i2c_hlc_comp_write(i2c, msgs);
goto out;
}
}
}
for (i = 0; ret == 0 && i < num; i++) {
struct i2c_msg *pmsg = &msgs[i];
/* zero-length messages are not supported */
if (!pmsg->len) {
ret = -EOPNOTSUPP;
break;
}
ret = octeon_i2c_start(i2c);
if (ret)
return ret;
if (pmsg->flags & I2C_M_RD)
ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf,
&pmsg->len, pmsg->flags & I2C_M_RECV_LEN);
else
ret = octeon_i2c_write(i2c, pmsg->addr, pmsg->buf,
pmsg->len);
}
octeon_i2c_stop(i2c);
out:
return (ret != 0) ? ret : num;
}
/* calculate and set clock divisors */
void octeon_i2c_set_clock(struct octeon_i2c *i2c)
{
int tclk, thp_base, inc, thp_idx, mdiv_idx, ndiv_idx, foscl, diff;
bool is_plat_otx2;
/*
* Find divisors to produce target frequency, start with large delta
* to cover wider range of divisors, note thp = TCLK half period and
* ds is OSCL output frequency divisor.
*/
unsigned int thp, mdiv_min, mdiv = 2, ndiv = 0, ds = 10;
unsigned int delta_hz = INITIAL_DELTA_HZ;
is_plat_otx2 = octeon_i2c_is_otx2(to_pci_dev(i2c->dev));
if (is_plat_otx2) {
thp = TWSI_MASTER_CLK_REG_OTX2_VAL;
mdiv_min = 0;
if (!IS_LS_FREQ(i2c->twsi_freq))
ds = 15;
} else {
thp = TWSI_MASTER_CLK_REG_DEF_VAL;
mdiv_min = 2;
}
for (ndiv_idx = 0; ndiv_idx < 8 && delta_hz != 0; ndiv_idx++) {
/*
* An mdiv value of less than 2 seems to not work well
* with ds1337 RTCs, so we constrain it to larger values.
*/
for (mdiv_idx = 15; mdiv_idx >= mdiv_min && delta_hz != 0; mdiv_idx--) {
/*
* For given ndiv and mdiv values check the
* two closest thp values.
*/
tclk = i2c->twsi_freq * (mdiv_idx + 1) * ds;
tclk *= (1 << ndiv_idx);
if (is_plat_otx2)
thp_base = (i2c->sys_freq / tclk) - 2;
else
thp_base = (i2c->sys_freq / (tclk * 2)) - 1;
for (inc = 0; inc <= 1; inc++) {
thp_idx = thp_base + inc;
if (thp_idx < 5 || thp_idx > 0xff)
continue;
if (is_plat_otx2)
foscl = i2c->sys_freq / (thp_idx + 2);
else
foscl = i2c->sys_freq /
(2 * (thp_idx + 1));
foscl = foscl / (1 << ndiv_idx);
foscl = foscl / (mdiv_idx + 1) / ds;
if (foscl > i2c->twsi_freq)
continue;
diff = abs(foscl - i2c->twsi_freq);
/*
* Diff holds difference between calculated frequency
* value vs desired frequency.
* Delta_hz is updated with last minimum diff.
*/
if (diff < delta_hz) {
delta_hz = diff;
thp = thp_idx;
mdiv = mdiv_idx;
ndiv = ndiv_idx;
}
}
}
}
octeon_i2c_reg_write(i2c, SW_TWSI_OP_TWSI_CLK, thp);
octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv);
if (is_plat_otx2) {
u64 mode;
mode = __raw_readq(i2c->twsi_base + OCTEON_REG_MODE(i2c));
/* Set REFCLK_SRC and HS_MODE in TWSX_MODE register */
if (!IS_LS_FREQ(i2c->twsi_freq))
mode |= TWSX_MODE_HS_MASK;
else
mode &= ~TWSX_MODE_HS_MASK;
octeon_i2c_writeq_flush(mode, i2c->twsi_base + OCTEON_REG_MODE(i2c));
}
}
int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
{
u8 status = 0;
int tries;
/* reset controller */
octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_RST, 0);
for (tries = 10; tries && status != STAT_IDLE; tries--) {
udelay(1);
status = octeon_i2c_stat_read(i2c);
if (status == STAT_IDLE)
break;
}
if (status != STAT_IDLE) {
dev_err(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n",
__func__, status);
return -EIO;
}
/* toggle twice to force both teardowns */
octeon_i2c_hlc_enable(i2c);
octeon_i2c_hlc_disable(i2c);
return 0;
}
static int octeon_i2c_get_scl(struct i2c_adapter *adap)
{
struct octeon_i2c *i2c = i2c_get_adapdata(adap);
u64 state;
state = octeon_i2c_read_int(i2c);
return state & TWSI_INT_SCL;
}
static void octeon_i2c_set_scl(struct i2c_adapter *adap, int val)
{
struct octeon_i2c *i2c = i2c_get_adapdata(adap);
octeon_i2c_write_int(i2c, val ? 0 : TWSI_INT_SCL_OVR);
}
static int octeon_i2c_get_sda(struct i2c_adapter *adap)
{
struct octeon_i2c *i2c = i2c_get_adapdata(adap);
u64 state;
state = octeon_i2c_read_int(i2c);
return state & TWSI_INT_SDA;
}
static void octeon_i2c_prepare_recovery(struct i2c_adapter *adap)
{
struct octeon_i2c *i2c = i2c_get_adapdata(adap);
octeon_i2c_hlc_disable(i2c);
octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_RST, 0);
/* wait for software reset to settle */
udelay(5);
/*
* Bring control register to a good state regardless
* of HLC state.
*/
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
octeon_i2c_write_int(i2c, 0);
}
static void octeon_i2c_unprepare_recovery(struct i2c_adapter *adap)
{
struct octeon_i2c *i2c = i2c_get_adapdata(adap);
/*
* Generate STOP to finish the unfinished transaction.
* Can't generate STOP via the TWSI CTL register
* since it could bring the TWSI controller into an inoperable state.
*/
octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR | TWSI_INT_SCL_OVR);
udelay(5);
octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR);
udelay(5);
octeon_i2c_write_int(i2c, 0);
}
struct i2c_bus_recovery_info octeon_i2c_recovery_info = {
.recover_bus = i2c_generic_scl_recovery,
.get_scl = octeon_i2c_get_scl,
.set_scl = octeon_i2c_set_scl,
.get_sda = octeon_i2c_get_sda,
.prepare_recovery = octeon_i2c_prepare_recovery,
.unprepare_recovery = octeon_i2c_unprepare_recovery,
};
Codebase Browser
linux