u-boot/arch/x86/lib/scu.c
Simon Glass 41575d8e4c dm: treewide: Rename auto_alloc_size members to be shorter
This construct is quite long-winded. In earlier days it made some sense
since auto-allocation was a strange concept. But with driver model now
used pretty universally, we can shorten this to 'auto'. This reduces
verbosity and makes it easier to read.

Coincidentally it also ensures that every declaration is on one line,
thus making dtoc's job easier.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-12-13 08:00:25 -07:00

231 lines
5.3 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2017 Intel Corporation
*
* Intel Mobile Internet Devices (MID) based on Intel Atom SoCs have few
* microcontrollers inside to do some auxiliary tasks. One of such
* microcontroller is System Controller Unit (SCU) which, in particular,
* is servicing watchdog and controlling system reset function.
*
* This driver enables IPC channel to SCU.
*/
#include <common.h>
#include <dm.h>
#include <regmap.h>
#include <syscon.h>
#include <asm/cpu.h>
#include <asm/scu.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/kernel.h>
/* SCU register map */
struct ipc_regs {
u32 cmd;
u32 status;
u32 sptr;
u32 dptr;
u32 reserved[28];
u32 wbuf[4];
u32 rbuf[4];
};
struct scu {
struct ipc_regs *regs;
};
/**
* scu_ipc_send_command() - send command to SCU
* @regs: register map of SCU
* @cmd: command
*
* Command Register (Write Only):
* A write to this register results in an interrupt to the SCU core processor
* Format:
* |rfu2(8) | size(8) | command id(4) | rfu1(3) | ioc(1) | command(8)|
*/
static void scu_ipc_send_command(struct ipc_regs *regs, u32 cmd)
{
writel(cmd, &regs->cmd);
}
/**
* scu_ipc_check_status() - check status of last command
* @regs: register map of SCU
*
* Status Register (Read Only):
* Driver will read this register to get the ready/busy status of the IPC
* block and error status of the IPC command that was just processed by SCU
* Format:
* |rfu3(8)|error code(8)|initiator id(8)|cmd id(4)|rfu1(2)|error(1)|busy(1)|
*/
static int scu_ipc_check_status(struct ipc_regs *regs)
{
int loop_count = 100000;
int status;
do {
status = readl(&regs->status);
if (!(status & BIT(0)))
break;
udelay(1);
} while (--loop_count);
if (!loop_count)
return -ETIMEDOUT;
if (status & BIT(1)) {
printf("%s() status=0x%08x\n", __func__, status);
return -EIO;
}
return 0;
}
static int scu_ipc_cmd(struct ipc_regs *regs, u32 cmd, u32 sub,
u32 *in, int inlen, u32 *out, int outlen)
{
int i, err;
for (i = 0; i < inlen; i++)
writel(*in++, &regs->wbuf[i]);
scu_ipc_send_command(regs, (inlen << 16) | (sub << 12) | cmd);
err = scu_ipc_check_status(regs);
if (!err) {
for (i = 0; i < outlen; i++)
*out++ = readl(&regs->rbuf[i]);
}
return err;
}
/**
* scu_ipc_raw_command() - IPC command with data and pointers
* @cmd: IPC command code
* @sub: IPC command sub type
* @in: input data of this IPC command
* @inlen: input data length in dwords
* @out: output data of this IPC command
* @outlen: output data length in dwords
* @dptr: data writing to SPTR register
* @sptr: data writing to DPTR register
*
* Send an IPC command to SCU with input/output data and source/dest pointers.
*
* Return: an IPC error code or 0 on success.
*/
int scu_ipc_raw_command(u32 cmd, u32 sub, u32 *in, int inlen, u32 *out,
int outlen, u32 dptr, u32 sptr)
{
int inbuflen = DIV_ROUND_UP(inlen, 4);
struct udevice *dev;
struct scu *scu;
int ret;
ret = syscon_get_by_driver_data(X86_SYSCON_SCU, &dev);
if (ret)
return ret;
scu = dev_get_priv(dev);
/* Up to 16 bytes */
if (inbuflen > 4)
return -EINVAL;
writel(dptr, &scu->regs->dptr);
writel(sptr, &scu->regs->sptr);
/*
* SRAM controller doesn't support 8-bit writes, it only
* supports 32-bit writes, so we have to copy input data into
* the temporary buffer, and SCU FW will use the inlen to
* determine the actual input data length in the temporary
* buffer.
*/
u32 inbuf[4] = {0};
memcpy(inbuf, in, inlen);
return scu_ipc_cmd(scu->regs, cmd, sub, inbuf, inlen, out, outlen);
}
/**
* scu_ipc_simple_command() - send a simple command
* @cmd: command
* @sub: sub type
*
* Issue a simple command to the SCU. Do not use this interface if
* you must then access data as any data values may be overwritten
* by another SCU access by the time this function returns.
*
* This function may sleep. Locking for SCU accesses is handled for
* the caller.
*/
int scu_ipc_simple_command(u32 cmd, u32 sub)
{
struct scu *scu;
struct udevice *dev;
int ret;
ret = syscon_get_by_driver_data(X86_SYSCON_SCU, &dev);
if (ret)
return ret;
scu = dev_get_priv(dev);
scu_ipc_send_command(scu->regs, sub << 12 | cmd);
return scu_ipc_check_status(scu->regs);
}
/**
* scu_ipc_command - command with data
* @cmd: command
* @sub: sub type
* @in: input data
* @inlen: input length in dwords
* @out: output data
* @outlen: output length in dwords
*
* Issue a command to the SCU which involves data transfers.
*/
int scu_ipc_command(u32 cmd, u32 sub, u32 *in, int inlen, u32 *out, int outlen)
{
struct scu *scu;
struct udevice *dev;
int ret;
ret = syscon_get_by_driver_data(X86_SYSCON_SCU, &dev);
if (ret)
return ret;
scu = dev_get_priv(dev);
return scu_ipc_cmd(scu->regs, cmd, sub, in, inlen, out, outlen);
}
static int scu_ipc_probe(struct udevice *dev)
{
struct scu *scu = dev_get_priv(dev);
scu->regs = syscon_get_first_range(X86_SYSCON_SCU);
return 0;
}
static const struct udevice_id scu_ipc_match[] = {
{ .compatible = "intel,scu-ipc", .data = X86_SYSCON_SCU },
{ /* sentinel */ }
};
U_BOOT_DRIVER(scu_ipc) = {
.name = "scu_ipc",
.id = UCLASS_SYSCON,
.of_match = scu_ipc_match,
.probe = scu_ipc_probe,
.priv_auto = sizeof(struct scu),
};