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u-boot/drivers/i2c/intel_i2c.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2015 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*
* SMBus block read/write support added by Stefan Roese:
* Copyright (C) 2016 Stefan Roese <sr@denx.de>
*/
#include <common.h>
#include <dm.h>
#include <i2c.h>
#include <log.h>
#include <pci.h>
#include <asm/io.h>
/* PCI Configuration Space (D31:F3): SMBus */
#define SMB_BASE 0x20
#define HOSTC 0x40
#define HST_EN (1 << 0)
#define SMB_RCV_SLVA 0x09
/* SMBus I/O bits. */
#define SMBHSTSTAT 0x0
#define SMBHSTCTL 0x2
#define SMBHSTCMD 0x3
#define SMBXMITADD 0x4
#define SMBHSTDAT0 0x5
#define SMBHSTDAT1 0x6
#define SMBBLKDAT 0x7
#define SMBTRNSADD 0x9
#define SMBSLVDATA 0xa
#define SMBAUXCTL 0xd
#define SMLINK_PIN_CTL 0xe
#define SMBUS_PIN_CTL 0xf
/* I801 Hosts Status register bits */
#define SMBHSTSTS_BYTE_DONE 0x80
#define SMBHSTSTS_INUSE_STS 0x40
#define SMBHSTSTS_SMBALERT_STS 0x20
#define SMBHSTSTS_FAILED 0x10
#define SMBHSTSTS_BUS_ERR 0x08
#define SMBHSTSTS_DEV_ERR 0x04
#define SMBHSTSTS_INTR 0x02
#define SMBHSTSTS_HOST_BUSY 0x01
/* I801 Host Control register bits */
#define SMBHSTCNT_INTREN 0x01
#define SMBHSTCNT_KILL 0x02
#define SMBHSTCNT_LAST_BYTE 0x20
#define SMBHSTCNT_START 0x40
#define SMBHSTCNT_PEC_EN 0x80 /* ICH3 and later */
/* Auxiliary control register bits, ICH4+ only */
#define SMBAUXCTL_CRC 1
#define SMBAUXCTL_E32B 2
#define SMBUS_TIMEOUT 100 /* 100 ms */
struct intel_i2c {
u32 base;
int running;
};
static int smbus_wait_until_ready(u32 base)
{
unsigned long ts;
u8 byte;
ts = get_timer(0);
do {
byte = inb(base + SMBHSTSTAT);
if (!(byte & 1))
return 0;
} while (get_timer(ts) < SMBUS_TIMEOUT);
return -ETIMEDOUT;
}
static int smbus_wait_until_done(u32 base)
{
unsigned long ts;
u8 byte;
ts = get_timer(0);
do {
byte = inb(base + SMBHSTSTAT);
if (!((byte & 1) || (byte & ~((1 << 6) | (1 << 0))) == 0))
return 0;
} while (get_timer(ts) < SMBUS_TIMEOUT);
return -ETIMEDOUT;
}
static int smbus_block_read(u32 base, u8 dev, u8 *buffer,
int offset, int len)
{
u8 buf_temp[32];
int count;
int i;
debug("%s (%d): dev=0x%x offs=0x%x len=0x%x\n",
__func__, __LINE__, dev, offset, len);
if (smbus_wait_until_ready(base) < 0)
return -ETIMEDOUT;
/* Setup transaction */
/* Reset the data buffer index */
inb(base + SMBHSTCTL);
/* Set the device I'm talking too */
outb(((dev & 0x7f) << 1) | 1, base + SMBXMITADD);
/* Set the command/address... */
outb(offset & 0xff, base + SMBHSTCMD);
/* Set up for a block read */
outb((inb(base + SMBHSTCTL) & (~(0x7) << 2)) | (0x5 << 2),
(base + SMBHSTCTL));
/* Clear any lingering errors, so the transaction will run */
outb(inb(base + SMBHSTSTAT), base + SMBHSTSTAT);
/* Start the command */
outb((inb(base + SMBHSTCTL) | SMBHSTCNT_START), base + SMBHSTCTL);
/* Poll for transaction completion */
if (smbus_wait_until_done(base) < 0) {
printf("SMBUS read transaction timeout (dev=0x%x)\n", dev);
return -ETIMEDOUT;
}
count = inb(base + SMBHSTDAT0);
debug("%s (%d): count=%d (len=%d)\n", __func__, __LINE__, count, len);
if (count == 0) {
debug("ERROR: len=0 on read\n");
return -EIO;
}
if (count < len) {
debug("ERROR: too few bytes read\n");
return -EIO;
}
if (count > 32) {
debug("ERROR: count=%d too high\n", count);
return -EIO;
}
/* Read all available bytes from buffer */
for (i = 0; i < count; i++)
buf_temp[i] = inb(base + SMBBLKDAT);
memcpy(buffer, buf_temp, len);
/* Return results of transaction */
if (!(inb(base + SMBHSTSTAT) & SMBHSTSTS_INTR))
return -EIO;
return 0;
}
static int smbus_block_write(u32 base, u8 dev, u8 *buffer,
int offset, int len)
{
int i;
debug("%s (%d): dev=0x%x offs=0x%x len=0x%x\n",
__func__, __LINE__, dev, offset, len);
if (smbus_wait_until_ready(base) < 0)
return -ETIMEDOUT;
/* Setup transaction */
/* Set the device I'm talking too */
outb(((dev & 0x7f) << 1) & ~0x01, base + SMBXMITADD);
/* Set the command/address... */
outb(offset, base + SMBHSTCMD);
/* Set up for a block write */
outb((inb(base + SMBHSTCTL) & (~(0x7) << 2)) | (0x5 << 2),
(base + SMBHSTCTL));
/* Clear any lingering errors, so the transaction will run */
outb(inb(base + SMBHSTSTAT), base + SMBHSTSTAT);
/* Write count in DAT0 register */
outb(len, base + SMBHSTDAT0);
/* Write data bytes... */
for (i = 0; i < len; i++)
outb(*buffer++, base + SMBBLKDAT);
/* Start the command */
outb((inb(base + SMBHSTCTL) | SMBHSTCNT_START), base + SMBHSTCTL);
/* Poll for transaction completion */
if (smbus_wait_until_done(base) < 0) {
printf("SMBUS write transaction timeout (dev=0x%x)\n", dev);
return -ETIMEDOUT;
}
/* Return results of transaction */
if (!(inb(base + SMBHSTSTAT) & SMBHSTSTS_INTR))
return -EIO;
return 0;
}
static int intel_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
{
struct intel_i2c *i2c = dev_get_priv(bus);
struct i2c_msg *dmsg, *omsg, dummy;
debug("i2c_xfer: %d messages\n", nmsgs);
memset(&dummy, 0, sizeof(struct i2c_msg));
/*
* We expect either two messages (one with an offset and one with the
* actucal data) or one message (just data)
*/
if (nmsgs > 2 || nmsgs == 0) {
debug("%s: Only one or two messages are supported", __func__);
return -EIO;
}
omsg = nmsgs == 1 ? &dummy : msg;
dmsg = nmsgs == 1 ? msg : msg + 1;
if (dmsg->flags & I2C_M_RD)
return smbus_block_read(i2c->base, dmsg->addr, &dmsg->buf[0],
omsg->buf[0], dmsg->len);
else
return smbus_block_write(i2c->base, dmsg->addr, &dmsg->buf[1],
dmsg->buf[0], dmsg->len - 1);
}
static int intel_i2c_probe_chip(struct udevice *bus, uint chip_addr,
uint chip_flags)
{
struct intel_i2c *i2c = dev_get_priv(bus);
u8 buf[4];
return smbus_block_read(i2c->base, chip_addr, buf, 0, 1);
}
static int intel_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
{
return 0;
}
static int intel_i2c_probe(struct udevice *dev)
{
struct intel_i2c *priv = dev_get_priv(dev);
ulong base;
/* Save base address from PCI BAR */
priv->base = (ulong)dm_pci_map_bar(dev, PCI_BASE_ADDRESS_4,
PCI_REGION_IO);
base = priv->base;
/* Set SMBus enable. */
dm_pci_write_config8(dev, HOSTC, HST_EN);
/* Disable interrupts */
outb(inb(base + SMBHSTCTL) & ~SMBHSTCNT_INTREN, base + SMBHSTCTL);
/* Set 32-byte data buffer mode */
outb(inb(base + SMBAUXCTL) | SMBAUXCTL_E32B, base + SMBAUXCTL);
return 0;
}
static int intel_i2c_bind(struct udevice *dev)
{
char name[20];
/* Create a unique device name for PCI type devices */
if (device_is_on_pci_bus(dev)) {
sprintf(name, "intel_i2c#%u", dev_seq(dev));
device_set_name(dev, name);
}
return 0;
}
static const struct dm_i2c_ops intel_i2c_ops = {
.xfer = intel_i2c_xfer,
.probe_chip = intel_i2c_probe_chip,
.set_bus_speed = intel_i2c_set_bus_speed,
};
static const struct udevice_id intel_i2c_ids[] = {
{ .compatible = "intel,ich-i2c" },
{ }
};
U_BOOT_DRIVER(intel_i2c) = {
.name = "i2c_intel",
.id = UCLASS_I2C,
.of_match = intel_i2c_ids,
.ops = &intel_i2c_ops,
.priv_auto = sizeof(struct intel_i2c),
.bind = intel_i2c_bind,
.probe = intel_i2c_probe,
};
static struct pci_device_id intel_smbus_pci_supported[] = {
/* Intel BayTrail SMBus on the PCI bus */
{ PCI_VDEVICE(INTEL, 0x0f12) },
/* Intel IvyBridge (Panther Point PCH) SMBus on the PCI bus */
{ PCI_VDEVICE(INTEL, 0x1e22) },
{},
};
U_BOOT_PCI_DEVICE(intel_i2c, intel_smbus_pci_supported);