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u-boot/drivers/i2c/imx_lpi2c.c
Simon Glass 7c84319af9 dm: gpio: Correct use of -ENODEV in drivers 
In U-Boot -ENODEV means that there is no device. When there is a problem
with the device, drivers should return an error like -ENXIO or -EREMOTEIO.
When the device tree properties cannot be read correct , they should
return -EINVAL.

Update various GPIO drivers to follow this rule, to help with consistency
for future driver writers.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reported-by: Adam Ford <aford173@gmail.com>
2017-10-08 20:41:09 -06:00

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/*
* Copyright 2016 Freescale Semiconductors, Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <errno.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch/imx-regs.h>
#include <asm/arch/imx_lpi2c.h>
#include <asm/arch/sys_proto.h>
#include <dm.h>
#include <fdtdec.h>
#include <i2c.h>
DECLARE_GLOBAL_DATA_PTR;
#define LPI2C_FIFO_SIZE 4
#define LPI2C_TIMEOUT_MS 100
/* Weak linked function for overridden by some SoC power function */
int __weak init_i2c_power(unsigned i2c_num)
{
return 0;
}
static int imx_lpci2c_check_busy_bus(const struct imx_lpi2c_reg *regs)
{
lpi2c_status_t result = LPI2C_SUCESS;
u32 status;
status = readl(&regs->msr);
if ((status & LPI2C_MSR_BBF_MASK) && !(status & LPI2C_MSR_MBF_MASK))
result = LPI2C_BUSY;
return result;
}
static int imx_lpci2c_check_clear_error(struct imx_lpi2c_reg *regs)
{
lpi2c_status_t result = LPI2C_SUCESS;
u32 val, status;
status = readl(&regs->msr);
/* errors to check for */
status &= LPI2C_MSR_NDF_MASK | LPI2C_MSR_ALF_MASK |
LPI2C_MSR_FEF_MASK | LPI2C_MSR_PLTF_MASK;
if (status) {
if (status & LPI2C_MSR_PLTF_MASK)
result = LPI2C_PIN_LOW_TIMEOUT_ERR;
else if (status & LPI2C_MSR_ALF_MASK)
result = LPI2C_ARB_LOST_ERR;
else if (status & LPI2C_MSR_NDF_MASK)
result = LPI2C_NAK_ERR;
else if (status & LPI2C_MSR_FEF_MASK)
result = LPI2C_FIFO_ERR;
/* clear status flags */
writel(0x7f00, &regs->msr);
/* reset fifos */
val = readl(&regs->mcr);
val |= LPI2C_MCR_RRF_MASK | LPI2C_MCR_RTF_MASK;
writel(val, &regs->mcr);
}
return result;
}
static int bus_i2c_wait_for_tx_ready(struct imx_lpi2c_reg *regs)
{
lpi2c_status_t result = LPI2C_SUCESS;
u32 txcount = 0;
ulong start_time = get_timer(0);
do {
txcount = LPI2C_MFSR_TXCOUNT(readl(&regs->mfsr));
txcount = LPI2C_FIFO_SIZE - txcount;
result = imx_lpci2c_check_clear_error(regs);
if (result) {
debug("i2c: wait for tx ready: result 0x%x\n", result);
return result;
}
if (get_timer(start_time) > LPI2C_TIMEOUT_MS) {
debug("i2c: wait for tx ready: timeout\n");
return -1;
}
} while (!txcount);
return result;
}
static int bus_i2c_send(struct imx_lpi2c_reg *regs, u8 *txbuf, int len)
{
lpi2c_status_t result = LPI2C_SUCESS;
/* empty tx */
if (!len)
return result;
while (len--) {
result = bus_i2c_wait_for_tx_ready(regs);
if (result) {
debug("i2c: send wait fot tx ready: %d\n", result);
return result;
}
writel(*txbuf++, &regs->mtdr);
}
return result;
}
static int bus_i2c_receive(struct imx_lpi2c_reg *regs, u8 *rxbuf, int len)
{
lpi2c_status_t result = LPI2C_SUCESS;
u32 val;
ulong start_time = get_timer(0);
/* empty read */
if (!len)
return result;
result = bus_i2c_wait_for_tx_ready(regs);
if (result) {
debug("i2c: receive wait fot tx ready: %d\n", result);
return result;
}
/* clear all status flags */
writel(0x7f00, &regs->msr);
/* send receive command */
val = LPI2C_MTDR_CMD(0x1) | LPI2C_MTDR_DATA(len - 1);
writel(val, &regs->mtdr);
while (len--) {
do {
result = imx_lpci2c_check_clear_error(regs);
if (result) {
debug("i2c: receive check clear error: %d\n",
result);
return result;
}
if (get_timer(start_time) > LPI2C_TIMEOUT_MS) {
debug("i2c: receive mrdr: timeout\n");
return -1;
}
val = readl(&regs->mrdr);
} while (val & LPI2C_MRDR_RXEMPTY_MASK);
*rxbuf++ = LPI2C_MRDR_DATA(val);
}
return result;
}
static int bus_i2c_start(struct imx_lpi2c_reg *regs, u8 addr, u8 dir)
{
lpi2c_status_t result = LPI2C_SUCESS;
u32 val;
result = imx_lpci2c_check_busy_bus(regs);
if (result) {
debug("i2c: start check busy bus: 0x%x\n", result);
return result;
}
/* clear all status flags */
writel(0x7f00, &regs->msr);
/* turn off auto-stop condition */
val = readl(&regs->mcfgr1) & ~LPI2C_MCFGR1_AUTOSTOP_MASK;
writel(val, &regs->mcfgr1);
/* wait tx fifo ready */
result = bus_i2c_wait_for_tx_ready(regs);
if (result) {
debug("i2c: start wait for tx ready: 0x%x\n", result);
return result;
}
/* issue start command */
val = LPI2C_MTDR_CMD(0x4) | (addr << 0x1) | dir;
writel(val, &regs->mtdr);
return result;
}
static int bus_i2c_stop(struct imx_lpi2c_reg *regs)
{
lpi2c_status_t result = LPI2C_SUCESS;
u32 status;
result = bus_i2c_wait_for_tx_ready(regs);
if (result) {
debug("i2c: stop wait for tx ready: 0x%x\n", result);
return result;
}
/* send stop command */
writel(LPI2C_MTDR_CMD(0x2), &regs->mtdr);
while (result == LPI2C_SUCESS) {
status = readl(&regs->msr);
result = imx_lpci2c_check_clear_error(regs);
/* stop detect flag */
if (status & LPI2C_MSR_SDF_MASK) {
/* clear stop flag */
status &= LPI2C_MSR_SDF_MASK;
writel(status, &regs->msr);
break;
}
}
return result;
}
static int bus_i2c_read(struct imx_lpi2c_reg *regs, u32 chip, u8 *buf, int len)
{
lpi2c_status_t result = LPI2C_SUCESS;
result = bus_i2c_start(regs, chip, 1);
if (result)
return result;
result = bus_i2c_receive(regs, buf, len);
if (result)
return result;
result = bus_i2c_stop(regs);
if (result)
return result;
return result;
}
static int bus_i2c_write(struct imx_lpi2c_reg *regs, u32 chip, u8 *buf, int len)
{
lpi2c_status_t result = LPI2C_SUCESS;
result = bus_i2c_start(regs, chip, 0);
if (result)
return result;
result = bus_i2c_send(regs, buf, len);
if (result)
return result;
result = bus_i2c_stop(regs);
if (result)
return result;
return result;
}
static int bus_i2c_set_bus_speed(struct udevice *bus, int speed)
{
struct imx_lpi2c_reg *regs;
u32 val;
u32 preescale = 0, best_pre = 0, clkhi = 0;
u32 best_clkhi = 0, abs_error = 0, rate;
u32 error = 0xffffffff;
u32 clock_rate;
bool mode;
int i;
regs = (struct imx_lpi2c_reg *)devfdt_get_addr(bus);
clock_rate = imx_get_i2cclk(bus->seq + 4);
if (!clock_rate)
return -EPERM;
mode = (readl(&regs->mcr) & LPI2C_MCR_MEN_MASK) >> LPI2C_MCR_MEN_SHIFT;
/* disable master mode */
val = readl(&regs->mcr) & ~LPI2C_MCR_MEN_MASK;
writel(val | LPI2C_MCR_MEN(0), &regs->mcr);
for (preescale = 1; (preescale <= 128) &&
(error != 0); preescale = 2 * preescale) {
for (clkhi = 1; clkhi < 32; clkhi++) {
if (clkhi == 1)
rate = (clock_rate / preescale) / (1 + 3 + 2 + 2 / preescale);
else
rate = (clock_rate / preescale / (3 * clkhi + 2 + 2 / preescale));
abs_error = speed > rate ? speed - rate : rate - speed;
if (abs_error < error) {
best_pre = preescale;
best_clkhi = clkhi;
error = abs_error;
if (abs_error == 0)
break;
}
}
}
/* Standard, fast, fast mode plus and ultra-fast transfers. */
val = LPI2C_MCCR0_CLKHI(best_clkhi);
if (best_clkhi < 2)
val |= LPI2C_MCCR0_CLKLO(3) | LPI2C_MCCR0_SETHOLD(2) | LPI2C_MCCR0_DATAVD(1);
else
val |= LPI2C_MCCR0_CLKLO(2 * best_clkhi) | LPI2C_MCCR0_SETHOLD(best_clkhi) |
LPI2C_MCCR0_DATAVD(best_clkhi / 2);
writel(val, &regs->mccr0);
for (i = 0; i < 8; i++) {
if (best_pre == (1 << i)) {
best_pre = i;
break;
}
}
val = readl(&regs->mcfgr1) & ~LPI2C_MCFGR1_PRESCALE_MASK;
writel(val | LPI2C_MCFGR1_PRESCALE(best_pre), &regs->mcfgr1);
if (mode) {
val = readl(&regs->mcr) & ~LPI2C_MCR_MEN_MASK;
writel(val | LPI2C_MCR_MEN(1), &regs->mcr);
}
return 0;
}
static int bus_i2c_init(struct udevice *bus, int speed)
{
struct imx_lpi2c_reg *regs;
u32 val;
int ret;
regs = (struct imx_lpi2c_reg *)devfdt_get_addr(bus);
/* reset peripheral */
writel(LPI2C_MCR_RST_MASK, &regs->mcr);
writel(0x0, &regs->mcr);
/* Disable Dozen mode */
writel(LPI2C_MCR_DBGEN(0) | LPI2C_MCR_DOZEN(1), &regs->mcr);
/* host request disable, active high, external pin */
val = readl(&regs->mcfgr0);
val &= (~(LPI2C_MCFGR0_HREN_MASK | LPI2C_MCFGR0_HRPOL_MASK |
LPI2C_MCFGR0_HRSEL_MASK));
val |= LPI2C_MCFGR0_HRPOL(0x1);
writel(val, &regs->mcfgr0);
/* pincfg and ignore ack */
val = readl(&regs->mcfgr1);
val &= ~(LPI2C_MCFGR1_PINCFG_MASK | LPI2C_MCFGR1_IGNACK_MASK);
val |= LPI2C_MCFGR1_PINCFG(0x0); /* 2 pin open drain */
val |= LPI2C_MCFGR1_IGNACK(0x0); /* ignore nack */
writel(val, &regs->mcfgr1);
ret = bus_i2c_set_bus_speed(bus, speed);
/* enable lpi2c in master mode */
val = readl(&regs->mcr) & ~LPI2C_MCR_MEN_MASK;
writel(val | LPI2C_MCR_MEN(1), &regs->mcr);
debug("i2c : controller bus %d, speed %d:\n", bus->seq, speed);
return ret;
}
static int imx_lpi2c_probe_chip(struct udevice *bus, u32 chip,
u32 chip_flags)
{
struct imx_lpi2c_reg *regs;
lpi2c_status_t result = LPI2C_SUCESS;
regs = (struct imx_lpi2c_reg *)devfdt_get_addr(bus);
result = bus_i2c_start(regs, chip, 0);
if (result) {
bus_i2c_stop(regs);
bus_i2c_init(bus, 100000);
return result;
}
result = bus_i2c_stop(regs);
if (result) {
bus_i2c_init(bus, 100000);
return -result;
}
return result;
}
static int imx_lpi2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
{
struct imx_lpi2c_reg *regs;
int ret = 0;
regs = (struct imx_lpi2c_reg *)devfdt_get_addr(bus);
for (; nmsgs > 0; nmsgs--, msg++) {
debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
if (msg->flags & I2C_M_RD)
ret = bus_i2c_read(regs, msg->addr, msg->buf, msg->len);
else {
ret = bus_i2c_write(regs, msg->addr, msg->buf,
msg->len);
if (ret)
break;
}
}
if (ret)
debug("i2c_write: error sending\n");
return ret;
}
static int imx_lpi2c_set_bus_speed(struct udevice *bus, unsigned int speed)
{
return bus_i2c_set_bus_speed(bus, speed);
}
static int imx_lpi2c_probe(struct udevice *bus)
{
struct imx_lpi2c_bus *i2c_bus = dev_get_priv(bus);
fdt_addr_t addr;
int ret;
i2c_bus->driver_data = dev_get_driver_data(bus);
addr = devfdt_get_addr(bus);
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
i2c_bus->base = addr;
i2c_bus->index = bus->seq;
i2c_bus->bus = bus;
/* power up i2c resource */
ret = init_i2c_power(bus->seq + 4);
if (ret) {
debug("init_i2c_power err = %d\n", ret);
return ret;
}
/* Enable clk, only i2c4-7 can be handled by A7 core */
ret = enable_i2c_clk(1, bus->seq + 4);
if (ret < 0)
return ret;
ret = bus_i2c_init(bus, 100000);
if (ret < 0)
return ret;
debug("i2c : controller bus %d at %lu , speed %d: ",
bus->seq, i2c_bus->base,
i2c_bus->speed);
return 0;
}
static const struct dm_i2c_ops imx_lpi2c_ops = {
.xfer = imx_lpi2c_xfer,
.probe_chip = imx_lpi2c_probe_chip,
.set_bus_speed = imx_lpi2c_set_bus_speed,
};
static const struct udevice_id imx_lpi2c_ids[] = {
{ .compatible = "fsl,imx7ulp-lpi2c", },
{}
};
U_BOOT_DRIVER(imx_lpi2c) = {
.name = "imx_lpi2c",
.id = UCLASS_I2C,
.of_match = imx_lpi2c_ids,
.probe = imx_lpi2c_probe,
.priv_auto_alloc_size = sizeof(struct imx_lpi2c_bus),
.ops = &imx_lpi2c_ops,
};
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