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u-boot/drivers/i2c/exynos_hs_i2c.c
Masahiro Yamada 8613c8d897 treewide: convert (void *)devfdt_get_addr() to dev_read_addr_ptr() 
Use the _ptr suffixed variant instead of casting. Also, convert it to
dev_read_addr_ptr(), which is safe to CONFIG_OF_LIVE.

One curious part is an error check like follows in
drivers/watchdog/omap_wdt.c:

    priv->regs = (struct wd_timer *)devfdt_get_addr(dev);
    if (!priv->regs)
            return -EINVAL;

devfdt_get_addr() returns FDT_ADDR_T_NONE (i.e. -1) on error.
So, this code does not catch any error in DT parsing.

dev_read_addr_ptr() returns NULL on error, so this error check
will work.

I generated this commit by the following command:

 $ find . -name .git -prune -o -name '*.[ch]' -type f -print | \
   xargs sed -i -e 's/([^*)]*\*)devfdt_get_addr(/dev_read_addr_ptr(/'

I manually fixed drivers/usb/host/ehci-mx6.c

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2020-07-25 14:46:57 -06:00

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2016, Google Inc
*
* (C) Copyright 2002
* David Mueller, ELSOFT AG, d.mueller@elsoft.ch
*/
#include <common.h>
#include <dm.h>
#include <i2c.h>
#include <log.h>
#include <asm/arch/clk.h>
#include <asm/arch/cpu.h>
#include <asm/arch/pinmux.h>
#include <linux/delay.h>
#include "s3c24x0_i2c.h"
DECLARE_GLOBAL_DATA_PTR;
/* HSI2C-specific register description */
/* I2C_CTL Register bits */
#define HSI2C_FUNC_MODE_I2C (1u << 0)
#define HSI2C_MASTER (1u << 3)
#define HSI2C_RXCHON (1u << 6) /* Write/Send */
#define HSI2C_TXCHON (1u << 7) /* Read/Receive */
#define HSI2C_SW_RST (1u << 31)
/* I2C_FIFO_CTL Register bits */
#define HSI2C_RXFIFO_EN (1u << 0)
#define HSI2C_TXFIFO_EN (1u << 1)
#define HSI2C_TXFIFO_TRIGGER_LEVEL (0x20 << 16)
#define HSI2C_RXFIFO_TRIGGER_LEVEL (0x20 << 4)
/* I2C_TRAILING_CTL Register bits */
#define HSI2C_TRAILING_COUNT (0xff)
/* I2C_INT_EN Register bits */
#define HSI2C_TX_UNDERRUN_EN (1u << 2)
#define HSI2C_TX_OVERRUN_EN (1u << 3)
#define HSI2C_RX_UNDERRUN_EN (1u << 4)
#define HSI2C_RX_OVERRUN_EN (1u << 5)
#define HSI2C_INT_TRAILING_EN (1u << 6)
#define HSI2C_INT_I2C_EN (1u << 9)
#define HSI2C_INT_ERROR_MASK (HSI2C_TX_UNDERRUN_EN |\
HSI2C_TX_OVERRUN_EN |\
HSI2C_RX_UNDERRUN_EN |\
HSI2C_RX_OVERRUN_EN |\
HSI2C_INT_TRAILING_EN)
/* I2C_CONF Register bits */
#define HSI2C_AUTO_MODE (1u << 31)
#define HSI2C_10BIT_ADDR_MODE (1u << 30)
#define HSI2C_HS_MODE (1u << 29)
/* I2C_AUTO_CONF Register bits */
#define HSI2C_READ_WRITE (1u << 16)
#define HSI2C_STOP_AFTER_TRANS (1u << 17)
#define HSI2C_MASTER_RUN (1u << 31)
/* I2C_TIMEOUT Register bits */
#define HSI2C_TIMEOUT_EN (1u << 31)
/* I2C_TRANS_STATUS register bits */
#define HSI2C_MASTER_BUSY (1u << 17)
#define HSI2C_SLAVE_BUSY (1u << 16)
#define HSI2C_TIMEOUT_AUTO (1u << 4)
#define HSI2C_NO_DEV (1u << 3)
#define HSI2C_NO_DEV_ACK (1u << 2)
#define HSI2C_TRANS_ABORT (1u << 1)
#define HSI2C_TRANS_SUCCESS (1u << 0)
#define HSI2C_TRANS_ERROR_MASK (HSI2C_TIMEOUT_AUTO |\
HSI2C_NO_DEV | HSI2C_NO_DEV_ACK |\
HSI2C_TRANS_ABORT)
#define HSI2C_TRANS_FINISHED_MASK (HSI2C_TRANS_ERROR_MASK | HSI2C_TRANS_SUCCESS)
/* I2C_FIFO_STAT Register bits */
#define HSI2C_RX_FIFO_EMPTY (1u << 24)
#define HSI2C_RX_FIFO_FULL (1u << 23)
#define HSI2C_TX_FIFO_EMPTY (1u << 8)
#define HSI2C_TX_FIFO_FULL (1u << 7)
#define HSI2C_RX_FIFO_LEVEL(x) (((x) >> 16) & 0x7f)
#define HSI2C_TX_FIFO_LEVEL(x) ((x) & 0x7f)
#define HSI2C_SLV_ADDR_MAS(x) ((x & 0x3ff) << 10)
#define HSI2C_TIMEOUT_US 10000 /* 10 ms, finer granularity */
/*
* Wait for transfer completion.
*
* This function reads the interrupt status register waiting for the INT_I2C
* bit to be set, which indicates copletion of a transaction.
*
* @param i2c: pointer to the appropriate register bank
*
* @return: I2C_OK in case of successful completion, I2C_NOK_TIMEOUT in case
* the status bits do not get set in time, or an approrpiate error
* value in case of transfer errors.
*/
static int hsi2c_wait_for_trx(struct exynos5_hsi2c *i2c)
{
int i = HSI2C_TIMEOUT_US;
while (i-- > 0) {
u32 int_status = readl(&i2c->usi_int_stat);
if (int_status & HSI2C_INT_I2C_EN) {
u32 trans_status = readl(&i2c->usi_trans_status);
/* Deassert pending interrupt. */
writel(int_status, &i2c->usi_int_stat);
if (trans_status & HSI2C_NO_DEV_ACK) {
debug("%s: no ACK from device\n", __func__);
return I2C_NACK;
}
if (trans_status & HSI2C_NO_DEV) {
debug("%s: no device\n", __func__);
return I2C_NOK;
}
if (trans_status & HSI2C_TRANS_ABORT) {
debug("%s: arbitration lost\n", __func__);
return I2C_NOK_LA;
}
if (trans_status & HSI2C_TIMEOUT_AUTO) {
debug("%s: device timed out\n", __func__);
return I2C_NOK_TOUT;
}
return I2C_OK;
}
udelay(1);
}
debug("%s: transaction timeout!\n", __func__);
return I2C_NOK_TOUT;
}
static int hsi2c_get_clk_details(struct s3c24x0_i2c_bus *i2c_bus)
{
struct exynos5_hsi2c *hsregs = i2c_bus->hsregs;
ulong clkin;
unsigned int op_clk = i2c_bus->clock_frequency;
unsigned int i = 0, utemp0 = 0, utemp1 = 0;
unsigned int t_ftl_cycle;
#if (defined CONFIG_EXYNOS4 || defined CONFIG_EXYNOS5)
clkin = get_i2c_clk();
#else
clkin = get_PCLK();
#endif
/* FPCLK / FI2C =
* (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + 2 * FLT_CYCLE
* uTemp0 = (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2)
* uTemp1 = (TSCLK_L + TSCLK_H + 2)
* uTemp2 = TSCLK_L + TSCLK_H
*/
t_ftl_cycle = (readl(&hsregs->usi_conf) >> 16) & 0x7;
utemp0 = (clkin / op_clk) - 8 - 2 * t_ftl_cycle;
/* CLK_DIV max is 256 */
for (i = 0; i < 256; i++) {
utemp1 = utemp0 / (i + 1);
if ((utemp1 < 512) && (utemp1 > 4)) {
i2c_bus->clk_cycle = utemp1 - 2;
i2c_bus->clk_div = i;
return 0;
}
}
return -EINVAL;
}
static void hsi2c_ch_init(struct s3c24x0_i2c_bus *i2c_bus)
{
struct exynos5_hsi2c *hsregs = i2c_bus->hsregs;
unsigned int t_sr_release;
unsigned int n_clkdiv;
unsigned int t_start_su, t_start_hd;
unsigned int t_stop_su;
unsigned int t_data_su, t_data_hd;
unsigned int t_scl_l, t_scl_h;
u32 i2c_timing_s1;
u32 i2c_timing_s2;
u32 i2c_timing_s3;
u32 i2c_timing_sla;
n_clkdiv = i2c_bus->clk_div;
t_scl_l = i2c_bus->clk_cycle / 2;
t_scl_h = i2c_bus->clk_cycle / 2;
t_start_su = t_scl_l;
t_start_hd = t_scl_l;
t_stop_su = t_scl_l;
t_data_su = t_scl_l / 2;
t_data_hd = t_scl_l / 2;
t_sr_release = i2c_bus->clk_cycle;
i2c_timing_s1 = t_start_su << 24 | t_start_hd << 16 | t_stop_su << 8;
i2c_timing_s2 = t_data_su << 24 | t_scl_l << 8 | t_scl_h << 0;
i2c_timing_s3 = n_clkdiv << 16 | t_sr_release << 0;
i2c_timing_sla = t_data_hd << 0;
writel(HSI2C_TRAILING_COUNT, &hsregs->usi_trailing_ctl);
/* Clear to enable Timeout */
clrsetbits_le32(&hsregs->usi_timeout, HSI2C_TIMEOUT_EN, 0);
/* set AUTO mode */
writel(readl(&hsregs->usi_conf) | HSI2C_AUTO_MODE, &hsregs->usi_conf);
/* Enable completion conditions' reporting. */
writel(HSI2C_INT_I2C_EN, &hsregs->usi_int_en);
/* Enable FIFOs */
writel(HSI2C_RXFIFO_EN | HSI2C_TXFIFO_EN, &hsregs->usi_fifo_ctl);
/* Currently operating in Fast speed mode. */
writel(i2c_timing_s1, &hsregs->usi_timing_fs1);
writel(i2c_timing_s2, &hsregs->usi_timing_fs2);
writel(i2c_timing_s3, &hsregs->usi_timing_fs3);
writel(i2c_timing_sla, &hsregs->usi_timing_sla);
}
/* SW reset for the high speed bus */
static void exynos5_i2c_reset(struct s3c24x0_i2c_bus *i2c_bus)
{
struct exynos5_hsi2c *i2c = i2c_bus->hsregs;
u32 i2c_ctl;
/* Set and clear the bit for reset */
i2c_ctl = readl(&i2c->usi_ctl);
i2c_ctl |= HSI2C_SW_RST;
writel(i2c_ctl, &i2c->usi_ctl);
i2c_ctl = readl(&i2c->usi_ctl);
i2c_ctl &= ~HSI2C_SW_RST;
writel(i2c_ctl, &i2c->usi_ctl);
/* Initialize the configure registers */
hsi2c_ch_init(i2c_bus);
}
/*
* Poll the appropriate bit of the fifo status register until the interface is
* ready to process the next byte or timeout expires.
*
* In addition to the FIFO status register this function also polls the
* interrupt status register to be able to detect unexpected transaction
* completion.
*
* When FIFO is ready to process the next byte, this function returns I2C_OK.
* If in course of polling the INT_I2C assertion is detected, the function
* returns I2C_NOK. If timeout happens before any of the above conditions is
* met - the function returns I2C_NOK_TOUT;
* @param i2c: pointer to the appropriate i2c register bank.
* @param rx_transfer: set to True if the receive transaction is in progress.
* @return: as described above.
*/
static unsigned hsi2c_poll_fifo(struct exynos5_hsi2c *i2c, bool rx_transfer)
{
u32 fifo_bit = rx_transfer ? HSI2C_RX_FIFO_EMPTY : HSI2C_TX_FIFO_FULL;
int i = HSI2C_TIMEOUT_US;
while (readl(&i2c->usi_fifo_stat) & fifo_bit) {
if (readl(&i2c->usi_int_stat) & HSI2C_INT_I2C_EN) {
/*
* There is a chance that assertion of
* HSI2C_INT_I2C_EN and deassertion of
* HSI2C_RX_FIFO_EMPTY happen simultaneously. Let's
* give FIFO status priority and check it one more
* time before reporting interrupt. The interrupt will
* be reported next time this function is called.
*/
if (rx_transfer &&
!(readl(&i2c->usi_fifo_stat) & fifo_bit))
break;
return I2C_NOK;
}
if (!i--) {
debug("%s: FIFO polling timeout!\n", __func__);
return I2C_NOK_TOUT;
}
udelay(1);
}
return I2C_OK;
}
/*
* Preapre hsi2c transaction, either read or write.
*
* Set up transfer as described in section 27.5.1.2 'I2C Channel Auto Mode' of
* the 5420 UM.
*
* @param i2c: pointer to the appropriate i2c register bank.
* @param chip: slave address on the i2c bus (with read/write bit exlcuded)
* @param len: number of bytes expected to be sent or received
* @param rx_transfer: set to true for receive transactions
* @param: issue_stop: set to true if i2c stop condition should be generated
* after this transaction.
* @return: I2C_NOK_TOUT in case the bus remained busy for HSI2C_TIMEOUT_US,
* I2C_OK otherwise.
*/
static int hsi2c_prepare_transaction(struct exynos5_hsi2c *i2c,
u8 chip,
u16 len,
bool rx_transfer,
bool issue_stop)
{
u32 conf;
conf = len | HSI2C_MASTER_RUN;
if (issue_stop)
conf |= HSI2C_STOP_AFTER_TRANS;
/* Clear to enable Timeout */
writel(readl(&i2c->usi_timeout) & ~HSI2C_TIMEOUT_EN, &i2c->usi_timeout);
/* Set slave address */
writel(HSI2C_SLV_ADDR_MAS(chip), &i2c->i2c_addr);
if (rx_transfer) {
/* i2c master, read transaction */
writel((HSI2C_RXCHON | HSI2C_FUNC_MODE_I2C | HSI2C_MASTER),
&i2c->usi_ctl);
/* read up to len bytes, stop after transaction is finished */
writel(conf | HSI2C_READ_WRITE, &i2c->usi_auto_conf);
} else {
/* i2c master, write transaction */
writel((HSI2C_TXCHON | HSI2C_FUNC_MODE_I2C | HSI2C_MASTER),
&i2c->usi_ctl);
/* write up to len bytes, stop after transaction is finished */
writel(conf, &i2c->usi_auto_conf);
}
/* Reset all pending interrupt status bits we care about, if any */
writel(HSI2C_INT_I2C_EN, &i2c->usi_int_stat);
return I2C_OK;
}
/*
* Wait while i2c bus is settling down (mostly stop gets completed).
*/
static int hsi2c_wait_while_busy(struct exynos5_hsi2c *i2c)
{
int i = HSI2C_TIMEOUT_US;
while (readl(&i2c->usi_trans_status) & HSI2C_MASTER_BUSY) {
if (!i--) {
debug("%s: bus busy\n", __func__);
return I2C_NOK_TOUT;
}
udelay(1);
}
return I2C_OK;
}
static int hsi2c_write(struct exynos5_hsi2c *i2c,
unsigned char chip,
unsigned char addr[],
unsigned char alen,
unsigned char data[],
unsigned short len,
bool issue_stop)
{
int i, rv = 0;
if (!(len + alen)) {
/* Writes of zero length not supported in auto mode. */
debug("%s: zero length writes not supported\n", __func__);
return I2C_NOK;
}
rv = hsi2c_prepare_transaction
(i2c, chip, len + alen, false, issue_stop);
if (rv != I2C_OK)
return rv;
/* Move address, if any, and the data, if any, into the FIFO. */
for (i = 0; i < alen; i++) {
rv = hsi2c_poll_fifo(i2c, false);
if (rv != I2C_OK) {
debug("%s: address write failed\n", __func__);
goto write_error;
}
writel(addr[i], &i2c->usi_txdata);
}
for (i = 0; i < len; i++) {
rv = hsi2c_poll_fifo(i2c, false);
if (rv != I2C_OK) {
debug("%s: data write failed\n", __func__);
goto write_error;
}
writel(data[i], &i2c->usi_txdata);
}
rv = hsi2c_wait_for_trx(i2c);
write_error:
if (issue_stop) {
int tmp_ret = hsi2c_wait_while_busy(i2c);
if (rv == I2C_OK)
rv = tmp_ret;
}
writel(HSI2C_FUNC_MODE_I2C, &i2c->usi_ctl); /* done */
return rv;
}
static int hsi2c_read(struct exynos5_hsi2c *i2c,
unsigned char chip,
unsigned char addr[],
unsigned char alen,
unsigned char data[],
unsigned short len)
{
int i, rv, tmp_ret;
bool drop_data = false;
if (!len) {
/* Reads of zero length not supported in auto mode. */
debug("%s: zero length read adjusted\n", __func__);
drop_data = true;
len = 1;
}
if (alen) {
/* Internal register adress needs to be written first. */
rv = hsi2c_write(i2c, chip, addr, alen, NULL, 0, false);
if (rv != I2C_OK)
return rv;
}
rv = hsi2c_prepare_transaction(i2c, chip, len, true, true);
if (rv != I2C_OK)
return rv;
for (i = 0; i < len; i++) {
rv = hsi2c_poll_fifo(i2c, true);
if (rv != I2C_OK)
goto read_err;
if (drop_data)
continue;
data[i] = readl(&i2c->usi_rxdata);
}
rv = hsi2c_wait_for_trx(i2c);
read_err:
tmp_ret = hsi2c_wait_while_busy(i2c);
if (rv == I2C_OK)
rv = tmp_ret;
writel(HSI2C_FUNC_MODE_I2C, &i2c->usi_ctl); /* done */
return rv;
}
static int exynos_hs_i2c_xfer(struct udevice *dev, struct i2c_msg *msg,
int nmsgs)
{
struct s3c24x0_i2c_bus *i2c_bus = dev_get_priv(dev);
struct exynos5_hsi2c *hsregs = i2c_bus->hsregs;
int ret;
for (; nmsgs > 0; nmsgs--, msg++) {
if (msg->flags & I2C_M_RD) {
ret = hsi2c_read(hsregs, msg->addr, 0, 0, msg->buf,
msg->len);
} else {
ret = hsi2c_write(hsregs, msg->addr, 0, 0, msg->buf,
msg->len, true);
}
if (ret) {
exynos5_i2c_reset(i2c_bus);
return -EREMOTEIO;
}
}
return 0;
}
static int s3c24x0_i2c_set_bus_speed(struct udevice *dev, unsigned int speed)
{
struct s3c24x0_i2c_bus *i2c_bus = dev_get_priv(dev);
i2c_bus->clock_frequency = speed;
if (hsi2c_get_clk_details(i2c_bus))
return -EFAULT;
hsi2c_ch_init(i2c_bus);
return 0;
}
static int s3c24x0_i2c_probe(struct udevice *dev, uint chip, uint chip_flags)
{
struct s3c24x0_i2c_bus *i2c_bus = dev_get_priv(dev);
uchar buf[1];
int ret;
buf[0] = 0;
/*
* What is needed is to send the chip address and verify that the
* address was <ACK>ed (i.e. there was a chip at that address which
* drove the data line low).
*/
ret = hsi2c_read(i2c_bus->hsregs, chip, 0, 0, buf, 1);
return ret != I2C_OK;
}
static int s3c_i2c_ofdata_to_platdata(struct udevice *dev)
{
const void *blob = gd->fdt_blob;
struct s3c24x0_i2c_bus *i2c_bus = dev_get_priv(dev);
int node;
node = dev_of_offset(dev);
i2c_bus->hsregs = dev_read_addr_ptr(dev);
i2c_bus->id = pinmux_decode_periph_id(blob, node);
i2c_bus->clock_frequency =
dev_read_u32_default(dev, "clock-frequency",
I2C_SPEED_STANDARD_RATE);
i2c_bus->node = node;
i2c_bus->bus_num = dev->seq;
exynos_pinmux_config(i2c_bus->id, PINMUX_FLAG_HS_MODE);
i2c_bus->active = true;
return 0;
}
static const struct dm_i2c_ops exynos_hs_i2c_ops = {
.xfer = exynos_hs_i2c_xfer,
.probe_chip = s3c24x0_i2c_probe,
.set_bus_speed = s3c24x0_i2c_set_bus_speed,
};
static const struct udevice_id exynos_hs_i2c_ids[] = {
{ .compatible = "samsung,exynos5-hsi2c" },
{ }
};
U_BOOT_DRIVER(hs_i2c) = {
.name = "i2c_s3c_hs",
.id = UCLASS_I2C,
.of_match = exynos_hs_i2c_ids,
.ofdata_to_platdata = s3c_i2c_ofdata_to_platdata,
.priv_auto_alloc_size = sizeof(struct s3c24x0_i2c_bus),
.ops = &exynos_hs_i2c_ops,
};
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