blob: 2a81bc7de5f43d552941e43e3b066213a75e2bbc [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2022 Sean Anderson <sean.anderson@seco.com>
*
* This driver supports the Security Fuse Processor device found on some
* Layerscape processors. At the moment, we only support a few processors.
* This driver was written with reference to the Layerscape SDK User
* Guide [1] and the ATF SFP driver [2].
*
* [1] https://docs.nxp.com/bundle/GUID-487B2E69-BB19-42CB-AC38-7EF18C0FE3AE/page/GUID-27FC40AD-3321-4A82-B29E-7BB49EE94F23.html
* [2] https://source.codeaurora.org/external/qoriq/qoriq-components/atf/tree/drivers/nxp/sfp?h=github.com/master
*/
#define LOG_CATEGORY UCLASS_MISC
#include <common.h>
#include <clk.h>
#include <fuse.h>
#include <misc.h>
#include <asm/io.h>
#include <dm/device_compat.h>
#include <dm/read.h>
#include <linux/bitfield.h>
#include <power/regulator.h>
DECLARE_GLOBAL_DATA_PTR;
#define SFP_INGR 0x20
#define SFP_SVHESR 0x24
#define SFP_SFPCR 0x28
#define SFP_START 0x200
#define SFP_END 0x284
#define SFP_SIZE (SFP_END - SFP_START + 4)
#define SFP_INGR_ERR BIT(8)
#define SFP_INGR_INST GENMASK(7, 0)
#define SFP_INGR_READFB 0x01
#define SFP_INGR_PROGFB 0x02
#define SFP_SFPCR_PPW GENMASK(15, 0)
enum ls2_sfp_ioctl {
LS2_SFP_IOCTL_READ,
LS2_SFP_IOCTL_PROG,
};
/**
* struct ls2_sfp_priv - private data for LS2 SFP
* @base: Base address of SFP
* @supply: The (optional) supply for TA_PROG_SFP
* @programmed: Whether we've already programmed the fuses since the last
* reset. The SFP has a *very* limited amount of programming
* cycles (two to six, depending on the model), so we try and
* prevent accidentally performing additional programming
* cycles.
* @dirty: Whether the mirror registers have been written to (overridden)
* since we've last read the fuses (either as part of the reset
* process or using a READFB instruction). There is a much larger,
* but still finite, limit on the number of SFP read cycles (around
* 300,000), so we try and minimize reads as well.
*/
struct ls2_sfp_priv {
void __iomem *base;
struct udevice *supply;
bool programmed, dirty;
};
static u32 ls2_sfp_readl(struct ls2_sfp_priv *priv, ulong off)
{
u32 val = be32_to_cpu(readl(priv->base + off));
log_debug("%08x = readl(%p)\n", val, priv->base + off);
return val;
}
static void ls2_sfp_writel(struct ls2_sfp_priv *priv, ulong val, ulong off)
{
log_debug("writel(%08lx, %p)\n", val, priv->base + off);
writel(cpu_to_be32(val), priv->base + off);
}
static bool ls2_sfp_validate(struct udevice *dev, int offset, int size)
{
if (offset < 0 || size < 0) {
dev_notice(dev, "size and offset must be positive\n");
return false;
}
if (offset & 3 || size & 3) {
dev_notice(dev, "size and offset must be multiples of 4\n");
return false;
}
if (offset + size > SFP_SIZE) {
dev_notice(dev, "size + offset must be <= %#x\n", SFP_SIZE);
return false;
}
return true;
}
static int ls2_sfp_read(struct udevice *dev, int offset, void *buf_bytes,
int size)
{
int i;
struct ls2_sfp_priv *priv = dev_get_priv(dev);
u32 *buf = buf_bytes;
if (!ls2_sfp_validate(dev, offset, size))
return -EINVAL;
for (i = 0; i < size; i += 4)
buf[i >> 2] = ls2_sfp_readl(priv, SFP_START + offset + i);
return size;
}
static int ls2_sfp_write(struct udevice *dev, int offset,
const void *buf_bytes, int size)
{
int i;
struct ls2_sfp_priv *priv = dev_get_priv(dev);
const u32 *buf = buf_bytes;
if (!ls2_sfp_validate(dev, offset, size))
return -EINVAL;
for (i = 0; i < size; i += 4)
ls2_sfp_writel(priv, buf[i >> 2], SFP_START + offset + i);
priv->dirty = true;
return size;
}
static int ls2_sfp_check_secret(struct udevice *dev)
{
struct ls2_sfp_priv *priv = dev_get_priv(dev);
u32 svhesr = ls2_sfp_readl(priv, SFP_SVHESR);
if (svhesr) {
dev_warn(dev, "secret value hamming error not zero: %08x\n",
svhesr);
return -EIO;
}
return 0;
}
static int ls2_sfp_transaction(struct ls2_sfp_priv *priv, ulong inst)
{
u32 ingr;
ls2_sfp_writel(priv, inst, SFP_INGR);
do {
ingr = ls2_sfp_readl(priv, SFP_INGR);
} while (FIELD_GET(SFP_INGR_INST, ingr));
return FIELD_GET(SFP_INGR_ERR, ingr) ? -EIO : 0;
}
static int ls2_sfp_ioctl(struct udevice *dev, unsigned long request, void *buf)
{
int ret;
struct ls2_sfp_priv *priv = dev_get_priv(dev);
switch (request) {
case LS2_SFP_IOCTL_READ:
if (!priv->dirty) {
dev_dbg(dev, "ignoring read request, since fuses are not dirty\n");
return 0;
}
ret = ls2_sfp_transaction(priv, SFP_INGR_READFB);
if (ret) {
dev_err(dev, "error reading fuses\n");
return ret;
}
ls2_sfp_check_secret(dev);
priv->dirty = false;
return 0;
case LS2_SFP_IOCTL_PROG:
if (priv->programmed) {
dev_warn(dev, "fuses already programmed\n");
return -EPERM;
}
ret = ls2_sfp_check_secret(dev);
if (ret)
return ret;
if (priv->supply) {
ret = regulator_set_enable(priv->supply, true);
if (ret)
return ret;
}
ret = ls2_sfp_transaction(priv, SFP_INGR_PROGFB);
priv->programmed = true;
if (priv->supply)
regulator_set_enable(priv->supply, false);
if (ret)
dev_err(dev, "error programming fuses\n");
return ret;
default:
dev_dbg(dev, "unknown ioctl %lu\n", request);
return -EINVAL;
}
}
static const struct misc_ops ls2_sfp_ops = {
.read = ls2_sfp_read,
.write = ls2_sfp_write,
.ioctl = ls2_sfp_ioctl,
};
static int ls2_sfp_probe(struct udevice *dev)
{
int ret;
struct clk clk;
struct ls2_sfp_priv *priv = dev_get_priv(dev);
ulong rate;
priv->base = dev_read_addr_ptr(dev);
if (!priv->base) {
dev_dbg(dev, "could not read register base\n");
return -EINVAL;
}
ret = device_get_supply_regulator(dev, "ta-sfp-prog-supply", &priv->supply);
if (ret && ret != -ENODEV && ret != -ENOSYS) {
dev_dbg(dev, "problem getting supply (err %d)\n", ret);
return ret;
}
ret = clk_get_by_name(dev, "sfp", &clk);
if (ret == -ENOSYS) {
rate = gd->bus_clk / 4;
} else if (ret) {
dev_dbg(dev, "could not get clock (err %d)\n", ret);
return ret;
} else {
ret = clk_enable(&clk);
if (ret) {
dev_dbg(dev, "could not enable clock (err %d)\n", ret);
return ret;
}
rate = clk_get_rate(&clk);
clk_free(&clk);
if (!rate || IS_ERR_VALUE(rate)) {
ret = rate ? rate : -ENOENT;
dev_dbg(dev, "could not get clock rate (err %d)\n",
ret);
return ret;
}
}
/* sfp clock in MHz * 12 */
ls2_sfp_writel(priv, FIELD_PREP(SFP_SFPCR_PPW, rate * 12 / 1000000),
SFP_SFPCR);
ls2_sfp_check_secret(dev);
return 0;
}
static const struct udevice_id ls2_sfp_ids[] = {
{ .compatible = "fsl,ls1021a-sfp" },
{ }
};
U_BOOT_DRIVER(ls2_sfp) = {
.name = "ls2_sfp",
.id = UCLASS_MISC,
.of_match = ls2_sfp_ids,
.probe = ls2_sfp_probe,
.ops = &ls2_sfp_ops,
.priv_auto = sizeof(struct ls2_sfp_priv),
};
static int ls2_sfp_device(struct udevice **dev)
{
int ret = uclass_get_device_by_driver(UCLASS_MISC,
DM_DRIVER_GET(ls2_sfp), dev);
if (ret)
log_debug("device not found (err %d)\n", ret);
return ret;
}
int fuse_read(u32 bank, u32 word, u32 *val)
{
int ret;
struct udevice *dev;
ret = ls2_sfp_device(&dev);
if (ret)
return ret;
ret = misc_ioctl(dev, LS2_SFP_IOCTL_READ, NULL);
if (ret)
return ret;
ret = misc_read(dev, word << 2, val, sizeof(*val));
return ret < 0 ? ret : 0;
}
int fuse_sense(u32 bank, u32 word, u32 *val)
{
int ret;
struct udevice *dev;
ret = ls2_sfp_device(&dev);
if (ret)
return ret;
ret = misc_read(dev, word << 2, val, sizeof(*val));
return ret < 0 ? ret : 0;
}
int fuse_prog(u32 bank, u32 word, u32 val)
{
int ret;
struct udevice *dev;
ret = ls2_sfp_device(&dev);
if (ret)
return ret;
ret = misc_write(dev, word << 2, &val, sizeof(val));
if (ret < 0)
return ret;
return misc_ioctl(dev, LS2_SFP_IOCTL_PROG, NULL);
}
int fuse_override(u32 bank, u32 word, u32 val)
{
int ret;
struct udevice *dev;
ret = ls2_sfp_device(&dev);
if (ret)
return ret;
ret = misc_write(dev, word << 2, &val, sizeof(val));
return ret < 0 ? ret : 0;
}