mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-05 11:00:15 +00:00
d7b8fa1a6c
The Makefile name is npcm_i2c but the driver is npcm-i2c. Signed-off-by: Jim Liu <JJLIU0@nuvoton.com> Reviewed-by: Heiko Schocher <hs@denx.de>
630 lines
13 KiB
C
630 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* Copyright (c) 2021 Nuvoton Technology Corp.
|
|
*/
|
|
|
|
#include <clk.h>
|
|
#include <dm.h>
|
|
#include <i2c.h>
|
|
#include <asm/io.h>
|
|
#include <linux/iopoll.h>
|
|
#include <asm/arch/gcr.h>
|
|
|
|
#define I2C_FREQ_100K 100000
|
|
#define NPCM_I2C_TIMEOUT_MS 10
|
|
#define NPCM7XX_I2CSEGCTL_INIT_VAL 0x0333F000
|
|
#define NPCM8XX_I2CSEGCTL_INIT_VAL 0x9333F000
|
|
|
|
/* SCLFRQ min/max field values */
|
|
#define SCLFRQ_MIN 10
|
|
#define SCLFRQ_MAX 511
|
|
|
|
/* SMBCTL1 */
|
|
#define SMBCTL1_START BIT(0)
|
|
#define SMBCTL1_STOP BIT(1)
|
|
#define SMBCTL1_INTEN BIT(2)
|
|
#define SMBCTL1_ACK BIT(4)
|
|
#define SMBCTL1_STASTRE BIT(7)
|
|
|
|
/* SMBCTL2 */
|
|
#define SMBCTL2_ENABLE BIT(0)
|
|
|
|
/* SMBCTL3 */
|
|
#define SMBCTL3_SCL_LVL BIT(7)
|
|
#define SMBCTL3_SDA_LVL BIT(6)
|
|
|
|
/* SMBCST */
|
|
#define SMBCST_BB BIT(1)
|
|
#define SMBCST_TGSCL BIT(5)
|
|
|
|
/* SMBST */
|
|
#define SMBST_XMIT BIT(0)
|
|
#define SMBST_MASTER BIT(1)
|
|
#define SMBST_STASTR BIT(3)
|
|
#define SMBST_NEGACK BIT(4)
|
|
#define SMBST_BER BIT(5)
|
|
#define SMBST_SDAST BIT(6)
|
|
|
|
/* SMBCST3 in bank0 */
|
|
#define SMBCST3_EO_BUSY BIT(7)
|
|
|
|
/* SMBFIF_CTS in bank1 */
|
|
#define SMBFIF_CTS_CLR_FIFO BIT(6)
|
|
|
|
#define SMBFIF_CTL_FIFO_EN BIT(4)
|
|
#define SMBCTL3_BNK_SEL BIT(5)
|
|
|
|
enum {
|
|
I2C_ERR_NACK = 1,
|
|
I2C_ERR_BER,
|
|
I2C_ERR_TIMEOUT,
|
|
};
|
|
|
|
struct smb_bank0_regs {
|
|
u8 addr3;
|
|
u8 addr7;
|
|
u8 addr4;
|
|
u8 addr8;
|
|
u16 addr5;
|
|
u16 addr6;
|
|
u8 cst2;
|
|
u8 cst3;
|
|
u8 ctl4;
|
|
u8 ctl5;
|
|
u8 scllt;
|
|
u8 fif_ctl;
|
|
u8 sclht;
|
|
};
|
|
|
|
struct smb_bank1_regs {
|
|
u8 fif_cts;
|
|
u8 fair_per;
|
|
u16 txf_ctl;
|
|
u32 t_out;
|
|
u8 cst2;
|
|
u8 cst3;
|
|
u16 txf_sts;
|
|
u16 rxf_sts;
|
|
u8 rxf_ctl;
|
|
};
|
|
|
|
struct npcm_i2c_regs {
|
|
u16 sda;
|
|
u16 st;
|
|
u16 cst;
|
|
u16 ctl1;
|
|
u16 addr;
|
|
u16 ctl2;
|
|
u16 addr2;
|
|
u16 ctl3;
|
|
union {
|
|
struct smb_bank0_regs bank0;
|
|
struct smb_bank1_regs bank1;
|
|
};
|
|
|
|
};
|
|
|
|
struct npcm_i2c_bus {
|
|
struct npcm_i2c_regs *reg;
|
|
int num;
|
|
u32 apb_clk;
|
|
u32 freq;
|
|
bool started;
|
|
};
|
|
|
|
static void npcm_dump_regs(struct npcm_i2c_bus *bus)
|
|
{
|
|
struct npcm_i2c_regs *reg = bus->reg;
|
|
|
|
printf("\n");
|
|
printf("SMBST=0x%x\n", readb(®->st));
|
|
printf("SMBCST=0x%x\n", readb(®->cst));
|
|
printf("SMBCTL1=0x%x\n", readb(®->ctl1));
|
|
printf("\n");
|
|
}
|
|
|
|
static int npcm_i2c_check_sda(struct npcm_i2c_bus *bus)
|
|
{
|
|
struct npcm_i2c_regs *reg = bus->reg;
|
|
ulong start_time;
|
|
int err = I2C_ERR_TIMEOUT;
|
|
u8 val;
|
|
|
|
start_time = get_timer(0);
|
|
/* wait SDAST to be 1 */
|
|
while (get_timer(start_time) < NPCM_I2C_TIMEOUT_MS) {
|
|
val = readb(®->st);
|
|
if (val & SMBST_NEGACK) {
|
|
err = I2C_ERR_NACK;
|
|
break;
|
|
}
|
|
if (val & SMBST_BER) {
|
|
err = I2C_ERR_BER;
|
|
break;
|
|
}
|
|
if (val & SMBST_SDAST) {
|
|
err = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (err)
|
|
printf("%s: err %d\n", __func__, err);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int npcm_i2c_send_start(struct npcm_i2c_bus *bus)
|
|
{
|
|
struct npcm_i2c_regs *reg = bus->reg;
|
|
ulong start_time;
|
|
int err = I2C_ERR_TIMEOUT;
|
|
|
|
/* Generate START condition */
|
|
setbits_8(®->ctl1, SMBCTL1_START);
|
|
|
|
start_time = get_timer(0);
|
|
while (get_timer(start_time) < NPCM_I2C_TIMEOUT_MS) {
|
|
if (readb(®->st) & SMBST_BER)
|
|
return I2C_ERR_BER;
|
|
if (readb(®->st) & SMBST_MASTER) {
|
|
err = 0;
|
|
break;
|
|
}
|
|
}
|
|
bus->started = true;
|
|
|
|
return err;
|
|
}
|
|
|
|
static int npcm_i2c_send_stop(struct npcm_i2c_bus *bus, bool wait)
|
|
{
|
|
struct npcm_i2c_regs *reg = bus->reg;
|
|
ulong start_time;
|
|
int err = I2C_ERR_TIMEOUT;
|
|
|
|
setbits_8(®->ctl1, SMBCTL1_STOP);
|
|
|
|
/* Clear NEGACK, STASTR and BER bits */
|
|
writeb(SMBST_STASTR | SMBST_NEGACK | SMBST_BER, ®->st);
|
|
|
|
bus->started = false;
|
|
|
|
if (!wait)
|
|
return 0;
|
|
|
|
start_time = get_timer(0);
|
|
while (get_timer(start_time) < NPCM_I2C_TIMEOUT_MS) {
|
|
if ((readb(®->ctl1) & SMBCTL1_STOP) == 0) {
|
|
err = 0;
|
|
break;
|
|
}
|
|
}
|
|
if (err) {
|
|
printf("%s: err %d\n", __func__, err);
|
|
npcm_dump_regs(bus);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static void npcm_i2c_reset(struct npcm_i2c_bus *bus)
|
|
{
|
|
struct npcm_i2c_regs *reg = bus->reg;
|
|
|
|
debug("%s: module %d\n", __func__, bus->num);
|
|
/* disable & enable SMB moudle */
|
|
clrbits_8(®->ctl2, SMBCTL2_ENABLE);
|
|
setbits_8(®->ctl2, SMBCTL2_ENABLE);
|
|
|
|
/* clear BB and status */
|
|
writeb(SMBCST_BB, ®->cst);
|
|
writeb(0xff, ®->st);
|
|
|
|
/* select bank 1 */
|
|
setbits_8(®->ctl3, SMBCTL3_BNK_SEL);
|
|
/* Clear all fifo bits */
|
|
writeb(SMBFIF_CTS_CLR_FIFO, ®->bank1.fif_cts);
|
|
|
|
/* select bank 0 */
|
|
clrbits_8(®->ctl3, SMBCTL3_BNK_SEL);
|
|
/* clear EOB bit */
|
|
writeb(SMBCST3_EO_BUSY, ®->bank0.cst3);
|
|
/* single byte mode */
|
|
clrbits_8(®->bank0.fif_ctl, SMBFIF_CTL_FIFO_EN);
|
|
|
|
/* set POLL mode */
|
|
writeb(0, ®->ctl1);
|
|
}
|
|
|
|
static void npcm_i2c_recovery(struct npcm_i2c_bus *bus, u32 addr)
|
|
{
|
|
u8 val;
|
|
int iter = 27;
|
|
struct npcm_i2c_regs *reg = bus->reg;
|
|
int err;
|
|
|
|
val = readb(®->ctl3);
|
|
/* Skip recovery, bus not stucked */
|
|
if ((val & SMBCTL3_SCL_LVL) && (val & SMBCTL3_SDA_LVL))
|
|
return;
|
|
|
|
printf("Performing I2C bus %d recovery...\n", bus->num);
|
|
/* SCL/SDA are not releaed, perform recovery */
|
|
while (1) {
|
|
/* toggle SCL line */
|
|
writeb(SMBCST_TGSCL, ®->cst);
|
|
|
|
udelay(20);
|
|
val = readb(®->ctl3);
|
|
if (val & SMBCTL3_SDA_LVL)
|
|
break;
|
|
if (iter-- == 0)
|
|
break;
|
|
}
|
|
|
|
if (val & SMBCTL3_SDA_LVL) {
|
|
writeb((u8)((addr << 1) & 0xff), ®->sda);
|
|
err = npcm_i2c_send_start(bus);
|
|
if (!err) {
|
|
udelay(20);
|
|
npcm_i2c_send_stop(bus, false);
|
|
udelay(200);
|
|
printf("I2C bus %d recovery completed\n",
|
|
bus->num);
|
|
} else {
|
|
printf("%s: send START err %d\n", __func__, err);
|
|
}
|
|
} else {
|
|
printf("Fail to recover I2C bus %d\n", bus->num);
|
|
}
|
|
npcm_i2c_reset(bus);
|
|
}
|
|
|
|
static int npcm_i2c_send_address(struct npcm_i2c_bus *bus, u8 addr,
|
|
bool stall)
|
|
{
|
|
struct npcm_i2c_regs *reg = bus->reg;
|
|
ulong start_time;
|
|
u8 val;
|
|
|
|
/* Stall After Start Enable */
|
|
if (stall)
|
|
setbits_8(®->ctl1, SMBCTL1_STASTRE);
|
|
|
|
writeb(addr, ®->sda);
|
|
if (stall) {
|
|
start_time = get_timer(0);
|
|
while (get_timer(start_time) < NPCM_I2C_TIMEOUT_MS) {
|
|
if (readb(®->st) & SMBST_STASTR)
|
|
break;
|
|
|
|
if (readb(®->st) & SMBST_BER) {
|
|
clrbits_8(®->ctl1, SMBCTL1_STASTRE);
|
|
return I2C_ERR_BER;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* check ACK */
|
|
val = readb(®->st);
|
|
if (val & SMBST_NEGACK) {
|
|
debug("NACK on addr 0x%x\n", addr >> 1);
|
|
/* After a Stop condition, writing 1 to NEGACK clears it */
|
|
return I2C_ERR_NACK;
|
|
}
|
|
if (val & SMBST_BER)
|
|
return I2C_ERR_BER;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int npcm_i2c_read_bytes(struct npcm_i2c_bus *bus, u8 *data, int len)
|
|
{
|
|
struct npcm_i2c_regs *reg = bus->reg;
|
|
u8 val;
|
|
int i;
|
|
int err = 0;
|
|
|
|
if (len == 1) {
|
|
/* bus should be stalled before receiving last byte */
|
|
setbits_8(®->ctl1, SMBCTL1_ACK);
|
|
|
|
/* clear STASTRE if it is set */
|
|
if (readb(®->ctl1) & SMBCTL1_STASTRE) {
|
|
writeb(SMBST_STASTR, ®->st);
|
|
clrbits_8(®->ctl1, SMBCTL1_STASTRE);
|
|
}
|
|
npcm_i2c_check_sda(bus);
|
|
npcm_i2c_send_stop(bus, false);
|
|
*data = readb(®->sda);
|
|
/* this must be done to generate STOP condition */
|
|
writeb(SMBST_NEGACK, ®->st);
|
|
} else {
|
|
for (i = 0; i < len; i++) {
|
|
/*
|
|
* When NEGACK bit is set to 1 after the transmission of a byte,
|
|
* SDAST is not set to 1.
|
|
*/
|
|
if (i != (len - 1)) {
|
|
err = npcm_i2c_check_sda(bus);
|
|
} else {
|
|
err = readb_poll_timeout(®->ctl1, val,
|
|
!(val & SMBCTL1_ACK), 100000);
|
|
if (err) {
|
|
printf("wait nack timeout\n");
|
|
err = I2C_ERR_TIMEOUT;
|
|
npcm_dump_regs(bus);
|
|
}
|
|
}
|
|
if (err && err != I2C_ERR_TIMEOUT)
|
|
break;
|
|
if (i == (len - 2)) {
|
|
/* set NACK before last byte */
|
|
setbits_8(®->ctl1, SMBCTL1_ACK);
|
|
}
|
|
if (i == (len - 1)) {
|
|
/* last byte, send STOP condition */
|
|
npcm_i2c_send_stop(bus, false);
|
|
*data = readb(®->sda);
|
|
writeb(SMBST_NEGACK, ®->st);
|
|
break;
|
|
}
|
|
*data = readb(®->sda);
|
|
data++;
|
|
}
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int npcm_i2c_send_bytes(struct npcm_i2c_bus *bus, u8 *data, int len)
|
|
{
|
|
struct npcm_i2c_regs *reg = bus->reg;
|
|
u8 val;
|
|
int i;
|
|
int err = 0;
|
|
|
|
val = readb(®->st);
|
|
if (val & SMBST_NEGACK)
|
|
return I2C_ERR_NACK;
|
|
else if (val & SMBST_BER)
|
|
return I2C_ERR_BER;
|
|
|
|
/* clear STASTRE if it is set */
|
|
if (readb(®->ctl1) & SMBCTL1_STASTRE)
|
|
clrbits_8(®->ctl1, SMBCTL1_STASTRE);
|
|
|
|
for (i = 0; i < len; i++) {
|
|
err = npcm_i2c_check_sda(bus);
|
|
if (err)
|
|
break;
|
|
writeb(*data, ®->sda);
|
|
data++;
|
|
}
|
|
npcm_i2c_check_sda(bus);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int npcm_i2c_read(struct npcm_i2c_bus *bus, u32 addr, u8 *data,
|
|
u32 len)
|
|
{
|
|
struct npcm_i2c_regs *reg = bus->reg;
|
|
int err;
|
|
bool stall;
|
|
|
|
if (len <= 0)
|
|
return -EINVAL;
|
|
|
|
/* send START condition */
|
|
err = npcm_i2c_send_start(bus);
|
|
if (err) {
|
|
debug("%s: send START err %d\n", __func__, err);
|
|
return err;
|
|
}
|
|
|
|
stall = (len == 1) ? true : false;
|
|
/* send address byte */
|
|
err = npcm_i2c_send_address(bus, (u8)(addr << 1) | 0x1, stall);
|
|
|
|
if (!err && len)
|
|
npcm_i2c_read_bytes(bus, data, len);
|
|
|
|
if (err == I2C_ERR_NACK) {
|
|
/* clear NACK */
|
|
writeb(SMBST_NEGACK, ®->st);
|
|
}
|
|
|
|
if (err)
|
|
debug("%s: err %d\n", __func__, err);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int npcm_i2c_write(struct npcm_i2c_bus *bus, u32 addr, u8 *data,
|
|
u32 len)
|
|
{
|
|
struct npcm_i2c_regs *reg = bus->reg;
|
|
int err;
|
|
bool stall;
|
|
|
|
/* send START condition */
|
|
err = npcm_i2c_send_start(bus);
|
|
if (err) {
|
|
debug("%s: send START err %d\n", __func__, err);
|
|
return err;
|
|
}
|
|
|
|
stall = (len == 0) ? true : false;
|
|
/* send address byte */
|
|
err = npcm_i2c_send_address(bus, (u8)(addr << 1), stall);
|
|
|
|
if (!err && len)
|
|
err = npcm_i2c_send_bytes(bus, data, len);
|
|
|
|
/* clear STASTRE if it is set */
|
|
if (stall)
|
|
clrbits_8(®->ctl1, SMBCTL1_STASTRE);
|
|
|
|
if (err)
|
|
debug("%s: err %d\n", __func__, err);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int npcm_i2c_xfer(struct udevice *dev,
|
|
struct i2c_msg *msg, int nmsgs)
|
|
{
|
|
struct npcm_i2c_bus *bus = dev_get_priv(dev);
|
|
struct npcm_i2c_regs *reg = bus->reg;
|
|
int ret = 0, err = 0;
|
|
|
|
if (nmsgs < 1 || nmsgs > 2) {
|
|
printf("%s: commands not support\n", __func__);
|
|
return -EREMOTEIO;
|
|
}
|
|
/* clear ST register */
|
|
writeb(0xFF, ®->st);
|
|
|
|
for ( ; nmsgs > 0; nmsgs--, msg++) {
|
|
if (msg->flags & I2C_M_RD)
|
|
err = npcm_i2c_read(bus, msg->addr, msg->buf,
|
|
msg->len);
|
|
else
|
|
err = npcm_i2c_write(bus, msg->addr, msg->buf,
|
|
msg->len);
|
|
if (err) {
|
|
debug("i2c_xfer: error %d\n", err);
|
|
ret = -EREMOTEIO;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (bus->started)
|
|
npcm_i2c_send_stop(bus, true);
|
|
|
|
if (err)
|
|
npcm_i2c_recovery(bus, msg->addr);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int npcm_i2c_init_clk(struct npcm_i2c_bus *bus, u32 bus_freq)
|
|
{
|
|
struct npcm_i2c_regs *reg = bus->reg;
|
|
u32 freq = bus->apb_clk;
|
|
u32 sclfrq;
|
|
u8 hldt, val;
|
|
|
|
if (bus_freq > I2C_FREQ_100K) {
|
|
printf("Support standard mode only\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* SCLFRQ = T(SCL)/4/T(CLK) = FREQ(CLK)/4/FREQ(SCL) */
|
|
sclfrq = freq / (bus_freq * 4);
|
|
if (sclfrq < SCLFRQ_MIN || sclfrq > SCLFRQ_MAX)
|
|
return -EINVAL;
|
|
|
|
if (freq >= 40000000)
|
|
hldt = 17;
|
|
else if (freq >= 12500000)
|
|
hldt = 15;
|
|
else
|
|
hldt = 7;
|
|
|
|
val = readb(®->ctl2) & 0x1;
|
|
val |= (sclfrq & 0x7F) << 1;
|
|
writeb(val, ®->ctl2);
|
|
|
|
/* clear 400K_MODE bit */
|
|
val = readb(®->ctl3) & 0xc;
|
|
val |= (sclfrq >> 7) & 0x3;
|
|
writeb(val, ®->ctl3);
|
|
|
|
writeb(hldt, ®->bank0.ctl4);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int npcm_i2c_set_bus_speed(struct udevice *dev,
|
|
unsigned int speed)
|
|
{
|
|
struct npcm_i2c_bus *bus = dev_get_priv(dev);
|
|
|
|
return npcm_i2c_init_clk(bus, speed);
|
|
}
|
|
|
|
static int npcm_i2c_probe(struct udevice *dev)
|
|
{
|
|
struct npcm_i2c_bus *bus = dev_get_priv(dev);
|
|
struct npcm_gcr *gcr = (struct npcm_gcr *)NPCM_GCR_BA;
|
|
struct npcm_i2c_regs *reg;
|
|
u32 i2csegctl_val = dev_get_driver_data(dev);
|
|
struct clk clk;
|
|
int ret;
|
|
|
|
ret = clk_get_by_index(dev, 0, &clk);
|
|
if (ret) {
|
|
printf("%s: ret %d\n", __func__, ret);
|
|
return ret;
|
|
}
|
|
bus->apb_clk = clk_get_rate(&clk);
|
|
if (bus->apb_clk <= 0) {
|
|
printf("%s: fail to get rate\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
clk_free(&clk);
|
|
|
|
bus->num = dev->seq_;
|
|
bus->reg = dev_read_addr_ptr(dev);
|
|
bus->freq = dev_read_u32_default(dev, "clock-frequency", 100000);
|
|
bus->started = false;
|
|
reg = bus->reg;
|
|
|
|
if (npcm_i2c_init_clk(bus, bus->freq)) {
|
|
printf("%s: init_clk failed\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* set initial i2csegctl value */
|
|
writel(i2csegctl_val, &gcr->i2csegctl);
|
|
|
|
/* enable SMB module */
|
|
setbits_8(®->ctl2, SMBCTL2_ENABLE);
|
|
|
|
/* select register bank 0 */
|
|
clrbits_8(®->ctl3, SMBCTL3_BNK_SEL);
|
|
|
|
/* single byte mode */
|
|
clrbits_8(®->bank0.fif_ctl, SMBFIF_CTL_FIFO_EN);
|
|
|
|
/* set POLL mode */
|
|
writeb(0, ®->ctl1);
|
|
|
|
printf("I2C bus %d ready. speed=%d, base=0x%x, apb=%u\n",
|
|
bus->num, bus->freq, (u32)(uintptr_t)bus->reg, bus->apb_clk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct dm_i2c_ops nuvoton_i2c_ops = {
|
|
.xfer = npcm_i2c_xfer,
|
|
.set_bus_speed = npcm_i2c_set_bus_speed,
|
|
};
|
|
|
|
static const struct udevice_id nuvoton_i2c_of_match[] = {
|
|
{ .compatible = "nuvoton,npcm845-i2c", .data = NPCM8XX_I2CSEGCTL_INIT_VAL},
|
|
{ .compatible = "nuvoton,npcm750-i2c", .data = NPCM7XX_I2CSEGCTL_INIT_VAL},
|
|
{}
|
|
};
|
|
|
|
U_BOOT_DRIVER(npcm_i2c_bus) = {
|
|
.name = "npcm-i2c",
|
|
.id = UCLASS_I2C,
|
|
.of_match = nuvoton_i2c_of_match,
|
|
.probe = npcm_i2c_probe,
|
|
.priv_auto = sizeof(struct npcm_i2c_bus),
|
|
.ops = &nuvoton_i2c_ops,
|
|
};
|