u-boot/drivers/i2c/lpc32xx_i2c.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* LPC32xx I2C interface driver
*
* (C) Copyright 2014-2015 DENX Software Engineering GmbH
* Written-by: Albert ARIBAUD - 3ADEV <albert.aribaud@3adev.fr>
*/
#include <common.h>
#include <asm/io.h>
#include <i2c.h>
#include <linux/errno.h>
#include <asm/arch/clk.h>
#include <asm/arch/i2c.h>
#include <dm.h>
#include <mapmem.h>
/*
* Provide default speed and slave if target did not
*/
#if !defined(CONFIG_SYS_I2C_LPC32XX_SPEED)
#define CONFIG_SYS_I2C_LPC32XX_SPEED 350000
#endif
#if !defined(CONFIG_SYS_I2C_LPC32XX_SLAVE)
#define CONFIG_SYS_I2C_LPC32XX_SLAVE 0
#endif
/* TX register fields */
#define LPC32XX_I2C_TX_START 0x00000100
#define LPC32XX_I2C_TX_STOP 0x00000200
/* Control register values */
#define LPC32XX_I2C_SOFT_RESET 0x00000100
/* Status register values */
#define LPC32XX_I2C_STAT_TFF 0x00000400
#define LPC32XX_I2C_STAT_RFE 0x00000200
#define LPC32XX_I2C_STAT_DRMI 0x00000008
#define LPC32XX_I2C_STAT_NAI 0x00000004
#define LPC32XX_I2C_STAT_TDI 0x00000001
#ifndef CONFIG_DM_I2C
static struct lpc32xx_i2c_base *lpc32xx_i2c[] = {
(struct lpc32xx_i2c_base *)I2C1_BASE,
(struct lpc32xx_i2c_base *)I2C2_BASE,
(struct lpc32xx_i2c_base *)(USB_BASE + 0x300)
};
#endif
/* Set I2C bus speed */
static unsigned int __i2c_set_bus_speed(struct lpc32xx_i2c_base *base,
unsigned int speed, unsigned int chip)
{
int half_period;
if (speed == 0)
return -EINVAL;
/* OTG I2C clock source and CLK registers are different */
if (chip == 2) {
half_period = (get_periph_clk_rate() / speed) / 2;
if (half_period > 0xFF)
return -EINVAL;
} else {
half_period = (get_hclk_clk_rate() / speed) / 2;
if (half_period > 0x3FF)
return -EINVAL;
}
writel(half_period, &base->clk_hi);
writel(half_period, &base->clk_lo);
return 0;
}
/* I2C init called by cmd_i2c when doing 'i2c reset'. */
static void __i2c_init(struct lpc32xx_i2c_base *base,
int requested_speed, int slaveadd, unsigned int chip)
{
/* soft reset (auto-clears) */
writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl);
/* set HI and LO periods for half of the default speed */
__i2c_set_bus_speed(base, requested_speed, chip);
}
/* I2C probe called by cmd_i2c when doing 'i2c probe'. */
static int __i2c_probe_chip(struct lpc32xx_i2c_base *base, u8 dev)
{
int stat;
/* Soft-reset the controller */
writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl);
while (readl(&base->ctrl) & LPC32XX_I2C_SOFT_RESET)
;
/* Addre slave for write with start before and stop after */
writel((dev<<1) | LPC32XX_I2C_TX_START | LPC32XX_I2C_TX_STOP,
&base->tx);
/* wait for end of transation */
while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI))
;
/* was there no acknowledge? */
return (stat & LPC32XX_I2C_STAT_NAI) ? -1 : 0;
}
/*
* I2C read called by cmd_i2c when doing 'i2c read' and by cmd_eeprom.c
* Begin write, send address byte(s), begin read, receive data bytes, end.
*/
static int __i2c_read(struct lpc32xx_i2c_base *base, u8 dev, uint addr,
int alen, u8 *data, int length)
{
int stat, wlen;
/* Soft-reset the controller */
writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl);
while (readl(&base->ctrl) & LPC32XX_I2C_SOFT_RESET)
;
/* do we need to write an address at all? */
if (alen) {
/* Address slave in write mode */
writel((dev<<1) | LPC32XX_I2C_TX_START, &base->tx);
/* write address bytes */
while (alen--) {
/* compute address byte + stop for the last one */
int a = (addr >> (8 * alen)) & 0xff;
if (!alen)
a |= LPC32XX_I2C_TX_STOP;
/* Send address byte */
writel(a, &base->tx);
}
/* wait for end of transation */
while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI))
;
/* clear end-of-transaction flag */
writel(1, &base->stat);
}
/* do we have to read data at all? */
if (length) {
/* Address slave in read mode */
writel(1 | (dev<<1) | LPC32XX_I2C_TX_START, &base->tx);
wlen = length;
/* get data */
while (length | wlen) {
/* read status for TFF and RFE */
stat = readl(&base->stat);
/* must we, can we write a trigger byte? */
if ((wlen > 0)
& (!(stat & LPC32XX_I2C_STAT_TFF))) {
wlen--;
/* write trigger byte + stop if last */
writel(wlen ? 0 :
LPC32XX_I2C_TX_STOP, &base->tx);
}
/* must we, can we read a data byte? */
if ((length > 0)
& (!(stat & LPC32XX_I2C_STAT_RFE))) {
length--;
/* read byte */
*(data++) = readl(&base->rx);
}
}
/* wait for end of transation */
while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI))
;
/* clear end-of-transaction flag */
writel(1, &base->stat);
}
/* success */
return 0;
}
/*
* I2C write called by cmd_i2c when doing 'i2c write' and by cmd_eeprom.c
* Begin write, send address byte(s), send data bytes, end.
*/
static int __i2c_write(struct lpc32xx_i2c_base *base, u8 dev, uint addr,
int alen, u8 *data, int length)
{
int stat;
/* Soft-reset the controller */
writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl);
while (readl(&base->ctrl) & LPC32XX_I2C_SOFT_RESET)
;
/* do we need to write anything at all? */
if (alen | length)
/* Address slave in write mode */
writel((dev<<1) | LPC32XX_I2C_TX_START, &base->tx);
else
return 0;
/* write address bytes */
while (alen) {
/* wait for transmit fifo not full */
stat = readl(&base->stat);
if (!(stat & LPC32XX_I2C_STAT_TFF)) {
alen--;
int a = (addr >> (8 * alen)) & 0xff;
if (!(alen | length))
a |= LPC32XX_I2C_TX_STOP;
/* Send address byte */
writel(a, &base->tx);
}
}
while (length) {
/* wait for transmit fifo not full */
stat = readl(&base->stat);
if (!(stat & LPC32XX_I2C_STAT_TFF)) {
/* compute data byte, add stop if length==0 */
length--;
int d = *(data++);
if (!length)
d |= LPC32XX_I2C_TX_STOP;
/* Send data byte */
writel(d, &base->tx);
}
}
/* wait for end of transation */
while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI))
;
/* clear end-of-transaction flag */
writel(1, &base->stat);
return 0;
}
#ifndef CONFIG_DM_I2C
static void lpc32xx_i2c_init(struct i2c_adapter *adap,
int requested_speed, int slaveadd)
{
__i2c_init(lpc32xx_i2c[adap->hwadapnr], requested_speed, slaveadd,
adap->hwadapnr);
}
static int lpc32xx_i2c_probe_chip(struct i2c_adapter *adap, u8 dev)
{
return __i2c_probe_chip(lpc32xx_i2c[adap->hwadapnr], dev);
}
static int lpc32xx_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr,
int alen, u8 *data, int length)
{
return __i2c_read(lpc32xx_i2c[adap->hwadapnr], dev, addr,
alen, data, length);
}
static int lpc32xx_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr,
int alen, u8 *data, int length)
{
return __i2c_write(lpc32xx_i2c[adap->hwadapnr], dev, addr,
alen, data, length);
}
static unsigned int lpc32xx_i2c_set_bus_speed(struct i2c_adapter *adap,
unsigned int speed)
{
return __i2c_set_bus_speed(lpc32xx_i2c[adap->hwadapnr], speed,
adap->hwadapnr);
}
U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_0, lpc32xx_i2c_init, lpc32xx_i2c_probe_chip,
lpc32xx_i2c_read, lpc32xx_i2c_write,
lpc32xx_i2c_set_bus_speed,
CONFIG_SYS_I2C_LPC32XX_SPEED,
CONFIG_SYS_I2C_LPC32XX_SLAVE,
0)
U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_1, lpc32xx_i2c_init, lpc32xx_i2c_probe_chip,
lpc32xx_i2c_read, lpc32xx_i2c_write,
lpc32xx_i2c_set_bus_speed,
CONFIG_SYS_I2C_LPC32XX_SPEED,
CONFIG_SYS_I2C_LPC32XX_SLAVE,
1)
U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_2, lpc32xx_i2c_init, NULL,
lpc32xx_i2c_read, lpc32xx_i2c_write,
lpc32xx_i2c_set_bus_speed,
100000,
0,
2)
#else /* CONFIG_DM_I2C */
static int lpc32xx_i2c_probe(struct udevice *bus)
{
struct lpc32xx_i2c_dev *dev = dev_get_platdata(bus);
bus->seq = dev->index;
__i2c_init(dev->base, dev->speed, 0, dev->index);
return 0;
}
static int lpc32xx_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
u32 chip_flags)
{
struct lpc32xx_i2c_dev *dev = dev_get_platdata(bus);
return __i2c_probe_chip(dev->base, chip_addr);
}
static int lpc32xx_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
int nmsgs)
{
struct lpc32xx_i2c_dev *dev = dev_get_platdata(bus);
struct i2c_msg *dmsg, *omsg, dummy;
uint i = 0, address = 0;
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)
*/
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;
/* the address is expected to be a uint, not a array. */
address = omsg->buf[0];
for (i = 1; i < omsg->len; i++)
address = (address << 8) + omsg->buf[i];
if (dmsg->flags & I2C_M_RD)
return __i2c_read(dev->base, dmsg->addr, address,
omsg->len, dmsg->buf, dmsg->len);
else
return __i2c_write(dev->base, dmsg->addr, address,
omsg->len, dmsg->buf, dmsg->len);
}
static int lpc32xx_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
{
struct lpc32xx_i2c_dev *dev = dev_get_platdata(bus);
return __i2c_set_bus_speed(dev->base, speed, dev->index);
}
static int lpc32xx_i2c_reset(struct udevice *bus)
{
struct lpc32xx_i2c_dev *dev = dev_get_platdata(bus);
__i2c_init(dev->base, dev->speed, 0, dev->index);
return 0;
}
static const struct dm_i2c_ops lpc32xx_i2c_ops = {
.xfer = lpc32xx_i2c_xfer,
.probe_chip = lpc32xx_i2c_probe_chip,
.deblock = lpc32xx_i2c_reset,
.set_bus_speed = lpc32xx_i2c_set_bus_speed,
};
U_BOOT_DRIVER(i2c_lpc32xx) = {
.id = UCLASS_I2C,
.name = "i2c_lpc32xx",
.probe = lpc32xx_i2c_probe,
.ops = &lpc32xx_i2c_ops,
};
#endif /* CONFIG_DM_I2C */