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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2000
* Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
*
* (C) Copyright 2000 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
*
* (C) Copyright 2003 Pengutronix e.K.
* Robert Schwebel <r.schwebel@pengutronix.de>
*
* (C) Copyright 2011 Marvell Inc.
* Lei Wen <leiwen@marvell.com>
*
* Back ported to the 8xx platform (from the 8260 platform) by
* Murray.Jensen@cmst.csiro.au, 27-Jan-01.
*/
#include <dm.h>
#include <i2c.h>
#include <log.h>
#include <asm/io.h>
#include <linux/delay.h>
#include "mv_i2c.h"
/* All transfers are described by this data structure */
struct mv_i2c_msg {
u8 condition;
u8 acknack;
u8 direction;
u8 data;
};
#ifdef CONFIG_ARMADA_3700
/* Armada 3700 has no padding between the registers */
struct mv_i2c {
u32 ibmr;
u32 idbr;
u32 icr;
u32 isr;
u32 isar;
};
#else
struct mv_i2c {
u32 ibmr;
u32 pad0;
u32 idbr;
u32 pad1;
u32 icr;
u32 pad2;
u32 isr;
u32 pad3;
u32 isar;
};
#endif
/*
* Dummy implementation that can be overwritten by a board
* specific function
*/
__weak void i2c_clk_enable(void)
{
}
/*
* i2c_reset: - reset the host controller
*
*/
static void i2c_reset(struct mv_i2c *base)
{
u32 icr_mode;
/* Save bus mode (standard or fast speed) for later use */
icr_mode = readl(&base->icr) & ICR_MODE_MASK;
writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
writel(readl(&base->icr) | ICR_UR, &base->icr); /* reset the unit */
udelay(100);
writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
i2c_clk_enable();
writel(0x0, &base->isar); /* set our slave address */
/* set control reg values */
writel(I2C_ICR_INIT | icr_mode, &base->icr);
writel(I2C_ISR_INIT, &base->isr); /* set clear interrupt bits */
writel(readl(&base->icr) | ICR_IUE, &base->icr); /* enable unit */
udelay(100);
}
/*
* i2c_isr_set_cleared: - wait until certain bits of the I2C status register
* are set and cleared
*
* @return: 1 in case of success, 0 means timeout (no match within 10 ms).
*/
static int i2c_isr_set_cleared(struct mv_i2c *base, unsigned long set_mask,
unsigned long cleared_mask)
{
int timeout = 1000, isr;
do {
isr = readl(&base->isr);
udelay(10);
if (timeout-- < 0)
return 0;
} while (((isr & set_mask) != set_mask)
|| ((isr & cleared_mask) != 0));
return 1;
}
/*
* i2c_transfer: - Transfer one byte over the i2c bus
*
* This function can tranfer a byte over the i2c bus in both directions.
* It is used by the public API functions.
*
* @return: 0: transfer successful
* -1: message is empty
* -2: transmit timeout
* -3: ACK missing
* -4: receive timeout
* -5: illegal parameters
* -6: bus is busy and couldn't be aquired
*/
static int i2c_transfer(struct mv_i2c *base, struct mv_i2c_msg *msg)
{
int ret;
if (!msg)
goto transfer_error_msg_empty;
switch (msg->direction) {
case I2C_WRITE:
/* check if bus is not busy */
if (!i2c_isr_set_cleared(base, 0, ISR_IBB))
goto transfer_error_bus_busy;
/* start transmission */
writel(readl(&base->icr) & ~ICR_START, &base->icr);
writel(readl(&base->icr) & ~ICR_STOP, &base->icr);
writel(msg->data, &base->idbr);
if (msg->condition == I2C_COND_START)
writel(readl(&base->icr) | ICR_START, &base->icr);
if (msg->condition == I2C_COND_STOP)
writel(readl(&base->icr) | ICR_STOP, &base->icr);
if (msg->acknack == I2C_ACKNAK_SENDNAK)
writel(readl(&base->icr) | ICR_ACKNAK, &base->icr);
if (msg->acknack == I2C_ACKNAK_SENDACK)
writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr);
writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr);
writel(readl(&base->icr) | ICR_TB, &base->icr);
/* transmit register empty? */
if (!i2c_isr_set_cleared(base, ISR_ITE, 0))
goto transfer_error_transmit_timeout;
/* clear 'transmit empty' state */
writel(readl(&base->isr) | ISR_ITE, &base->isr);
/* wait for ACK from slave */
if (msg->acknack == I2C_ACKNAK_WAITACK)
if (!i2c_isr_set_cleared(base, 0, ISR_ACKNAK))
goto transfer_error_ack_missing;
break;
case I2C_READ:
/* check if bus is not busy */
if (!i2c_isr_set_cleared(base, 0, ISR_IBB))
goto transfer_error_bus_busy;
/* start receive */
writel(readl(&base->icr) & ~ICR_START, &base->icr);
writel(readl(&base->icr) & ~ICR_STOP, &base->icr);
if (msg->condition == I2C_COND_START)
writel(readl(&base->icr) | ICR_START, &base->icr);
if (msg->condition == I2C_COND_STOP)
writel(readl(&base->icr) | ICR_STOP, &base->icr);
if (msg->acknack == I2C_ACKNAK_SENDNAK)
writel(readl(&base->icr) | ICR_ACKNAK, &base->icr);
if (msg->acknack == I2C_ACKNAK_SENDACK)
writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr);
writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr);
writel(readl(&base->icr) | ICR_TB, &base->icr);
/* receive register full? */
if (!i2c_isr_set_cleared(base, ISR_IRF, 0))
goto transfer_error_receive_timeout;
msg->data = readl(&base->idbr);
/* clear 'receive empty' state */
writel(readl(&base->isr) | ISR_IRF, &base->isr);
break;
default:
goto transfer_error_illegal_param;
}
return 0;
transfer_error_msg_empty:
debug("i2c_transfer: error: 'msg' is empty\n");
ret = -1;
goto i2c_transfer_finish;
transfer_error_transmit_timeout:
debug("i2c_transfer: error: transmit timeout\n");
ret = -2;
goto i2c_transfer_finish;
transfer_error_ack_missing:
debug("i2c_transfer: error: ACK missing\n");
ret = -3;
goto i2c_transfer_finish;
transfer_error_receive_timeout:
debug("i2c_transfer: error: receive timeout\n");
ret = -4;
goto i2c_transfer_finish;
transfer_error_illegal_param:
debug("i2c_transfer: error: illegal parameters\n");
ret = -5;
goto i2c_transfer_finish;
transfer_error_bus_busy:
debug("i2c_transfer: error: bus is busy\n");
ret = -6;
goto i2c_transfer_finish;
i2c_transfer_finish:
debug("i2c_transfer: ISR: 0x%04x\n", readl(&base->isr));
i2c_reset(base);
return ret;
}
static int __i2c_read(struct mv_i2c *base, uchar chip, u8 *addr, int alen,
uchar *buffer, int len)
{
struct mv_i2c_msg msg;
debug("i2c_read(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
"len=0x%02x)\n", chip, *addr, alen, len);
if (len == 0) {
printf("reading zero byte is invalid\n");
return -EINVAL;
}
i2c_reset(base);
/* dummy chip address write */
debug("i2c_read: dummy chip address write\n");
msg.condition = I2C_COND_START;
msg.acknack = I2C_ACKNAK_WAITACK;
msg.direction = I2C_WRITE;
msg.data = (chip << 1);
msg.data &= 0xFE;
if (i2c_transfer(base, &msg))
return -1;
/*
* send memory address bytes;
* alen defines how much bytes we have to send.
*/
while (--alen >= 0) {
debug("i2c_read: send address byte %02x (alen=%d)\n",
*addr, alen);
msg.condition = I2C_COND_NORMAL;
msg.acknack = I2C_ACKNAK_WAITACK;
msg.direction = I2C_WRITE;
msg.data = addr[alen];
if (i2c_transfer(base, &msg))
return -1;
}
/* start read sequence */
debug("i2c_read: start read sequence\n");
msg.condition = I2C_COND_START;
msg.acknack = I2C_ACKNAK_WAITACK;
msg.direction = I2C_WRITE;
msg.data = (chip << 1);
msg.data |= 0x01;
if (i2c_transfer(base, &msg))
return -1;
/* read bytes; send NACK at last byte */
while (len--) {
if (len == 0) {
msg.condition = I2C_COND_STOP;
msg.acknack = I2C_ACKNAK_SENDNAK;
} else {
msg.condition = I2C_COND_NORMAL;
msg.acknack = I2C_ACKNAK_SENDACK;
}
msg.direction = I2C_READ;
msg.data = 0x00;
if (i2c_transfer(base, &msg))
return -1;
*buffer = msg.data;
debug("i2c_read: reading byte (%p)=0x%02x\n",
buffer, *buffer);
buffer++;
}
i2c_reset(base);
return 0;
}
static int __i2c_write(struct mv_i2c *base, uchar chip, u8 *addr, int alen,
uchar *buffer, int len)
{
struct mv_i2c_msg msg;
debug("i2c_write(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
"len=0x%02x)\n", chip, *addr, alen, len);
i2c_reset(base);
/* chip address write */
debug("i2c_write: chip address write\n");
msg.condition = I2C_COND_START;
msg.acknack = I2C_ACKNAK_WAITACK;
msg.direction = I2C_WRITE;
msg.data = (chip << 1);
msg.data &= 0xFE;
if (i2c_transfer(base, &msg))
return -1;
/*
* send memory address bytes;
* alen defines how much bytes we have to send.
*/
while (--alen >= 0) {
debug("i2c_read: send address byte %02x (alen=%d)\n",
*addr, alen);
msg.condition = I2C_COND_NORMAL;
msg.acknack = I2C_ACKNAK_WAITACK;
msg.direction = I2C_WRITE;
msg.data = addr[alen];
if (i2c_transfer(base, &msg))
return -1;
}
/* write bytes; send NACK at last byte */
while (len--) {
debug("i2c_write: writing byte (%p)=0x%02x\n",
buffer, *buffer);
if (len == 0)
msg.condition = I2C_COND_STOP;
else
msg.condition = I2C_COND_NORMAL;
msg.acknack = I2C_ACKNAK_WAITACK;
msg.direction = I2C_WRITE;
msg.data = *(buffer++);
if (i2c_transfer(base, &msg))
return -1;
}
i2c_reset(base);
return 0;
}
#if !CONFIG_IS_ENABLED(DM_I2C)
static struct mv_i2c *base_glob;
/* API Functions */
void i2c_init(int speed, int slaveaddr)
{
u32 val;
base_glob = (struct mv_i2c *)CONFIG_MV_I2C_REG;
if (speed > I2C_SPEED_STANDARD_RATE)
val = ICR_FM;
else
val = ICR_SM;
clrsetbits_le32(&base_glob->icr, ICR_MODE_MASK, val);
}
static int __i2c_probe_chip(struct mv_i2c *base, uchar chip)
{
struct mv_i2c_msg msg;
i2c_reset(base);
msg.condition = I2C_COND_START;
msg.acknack = I2C_ACKNAK_WAITACK;
msg.direction = I2C_WRITE;
msg.data = (chip << 1) + 1;
if (i2c_transfer(base, &msg))
return -1;
msg.condition = I2C_COND_STOP;
msg.acknack = I2C_ACKNAK_SENDNAK;
msg.direction = I2C_READ;
msg.data = 0x00;
if (i2c_transfer(base, &msg))
return -1;
return 0;
}
/*
* i2c_probe: - Test if a chip answers for a given i2c address
*
* @chip: address of the chip which is searched for
* @return: 0 if a chip was found, -1 otherwhise
*/
int i2c_probe(uchar chip)
{
return __i2c_probe_chip(base_glob, chip);
}
/*
* i2c_read: - Read multiple bytes from an i2c device
*
* The higher level routines take into account that this function is only
* called with len < page length of the device (see configuration file)
*
* @chip: address of the chip which is to be read
* @addr: i2c data address within the chip
* @alen: length of the i2c data address (1..2 bytes)
* @buffer: where to write the data
* @len: how much byte do we want to read
* @return: 0 in case of success
*/
int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
u8 addr_bytes[4];
addr_bytes[0] = (addr >> 0) & 0xFF;
addr_bytes[1] = (addr >> 8) & 0xFF;
addr_bytes[2] = (addr >> 16) & 0xFF;
addr_bytes[3] = (addr >> 24) & 0xFF;
return __i2c_read(base_glob, chip, addr_bytes, alen, buffer, len);
}
/*
* i2c_write: - Write multiple bytes to an i2c device
*
* The higher level routines take into account that this function is only
* called with len < page length of the device (see configuration file)
*
* @chip: address of the chip which is to be written
* @addr: i2c data address within the chip
* @alen: length of the i2c data address (1..2 bytes)
* @buffer: where to find the data to be written
* @len: how much byte do we want to read
* @return: 0 in case of success
*/
int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
u8 addr_bytes[4];
addr_bytes[0] = (addr >> 0) & 0xFF;
addr_bytes[1] = (addr >> 8) & 0xFF;
addr_bytes[2] = (addr >> 16) & 0xFF;
addr_bytes[3] = (addr >> 24) & 0xFF;
return __i2c_write(base_glob, chip, addr_bytes, alen, buffer, len);
}
#else /* CONFIG_DM_I2C */
struct mv_i2c_priv {
struct mv_i2c *base;
};
static int mv_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
{
struct mv_i2c_priv *i2c = dev_get_priv(bus);
struct i2c_msg *dmsg, *omsg, dummy;
memset(&dummy, 0, sizeof(struct i2c_msg));
/*
* We expect either two messages (one with an offset and one with the
* actual data) or one message (just data or offset/data combined)
*/
if (nmsgs > 2 || nmsgs == 0) {
debug("%s: Only one or two messages are supported.", __func__);
return -1;
}
omsg = nmsgs == 1 ? &dummy : msg;
dmsg = nmsgs == 1 ? msg : msg + 1;
if (dmsg->flags & I2C_M_RD)
return __i2c_read(i2c->base, dmsg->addr, omsg->buf,
omsg->len, dmsg->buf, dmsg->len);
else
return __i2c_write(i2c->base, dmsg->addr, omsg->buf,
omsg->len, dmsg->buf, dmsg->len);
}
static int mv_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
{
struct mv_i2c_priv *priv = dev_get_priv(bus);
u32 val;
if (speed > I2C_SPEED_STANDARD_RATE)
val = ICR_FM;
else
val = ICR_SM;
clrsetbits_le32(&priv->base->icr, ICR_MODE_MASK, val);
return 0;
}
static int mv_i2c_probe(struct udevice *bus)
{
struct mv_i2c_priv *priv = dev_get_priv(bus);
priv->base = dev_read_addr_ptr(bus);
return 0;
}
static const struct dm_i2c_ops mv_i2c_ops = {
.xfer = mv_i2c_xfer,
.set_bus_speed = mv_i2c_set_bus_speed,
};
static const struct udevice_id mv_i2c_ids[] = {
{ .compatible = "marvell,armada-3700-i2c" },
{ }
};
U_BOOT_DRIVER(i2c_mv) = {
.name = "i2c_mv",
.id = UCLASS_I2C,
.of_match = mv_i2c_ids,
.probe = mv_i2c_probe,
.priv_auto = sizeof(struct mv_i2c_priv),
.ops = &mv_i2c_ops,
};
#endif /* CONFIG_DM_I2C */