linux/linux-5.18.11/drivers/nvmem/qfprom.c

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2024-03-22 18:12:32 +00:00
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
*/
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/nvmem-provider.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/property.h>
#include <linux/regulator/consumer.h>
/* Blow timer clock frequency in Mhz */
#define QFPROM_BLOW_TIMER_OFFSET 0x03c
/* Amount of time required to hold charge to blow fuse in micro-seconds */
#define QFPROM_FUSE_BLOW_POLL_US 100
#define QFPROM_FUSE_BLOW_TIMEOUT_US 10000
#define QFPROM_BLOW_STATUS_OFFSET 0x048
#define QFPROM_BLOW_STATUS_BUSY 0x1
#define QFPROM_BLOW_STATUS_READY 0x0
#define QFPROM_ACCEL_OFFSET 0x044
#define QFPROM_VERSION_OFFSET 0x0
#define QFPROM_MAJOR_VERSION_SHIFT 28
#define QFPROM_MAJOR_VERSION_MASK GENMASK(31, QFPROM_MAJOR_VERSION_SHIFT)
#define QFPROM_MINOR_VERSION_SHIFT 16
#define QFPROM_MINOR_VERSION_MASK GENMASK(27, QFPROM_MINOR_VERSION_SHIFT)
static bool read_raw_data;
module_param(read_raw_data, bool, 0644);
MODULE_PARM_DESC(read_raw_data, "Read raw instead of corrected data");
/**
* struct qfprom_soc_data - config that varies from SoC to SoC.
*
* @accel_value: Should contain qfprom accel value.
* @qfprom_blow_timer_value: The timer value of qfprom when doing efuse blow.
* @qfprom_blow_set_freq: The frequency required to set when we start the
* fuse blowing.
* @qfprom_blow_uV: LDO voltage to be set when doing efuse blow
*/
struct qfprom_soc_data {
u32 accel_value;
u32 qfprom_blow_timer_value;
u32 qfprom_blow_set_freq;
int qfprom_blow_uV;
};
/**
* struct qfprom_priv - structure holding qfprom attributes
*
* @qfpraw: iomapped memory space for qfprom-efuse raw address space.
* @qfpconf: iomapped memory space for qfprom-efuse configuration address
* space.
* @qfpcorrected: iomapped memory space for qfprom corrected address space.
* @qfpsecurity: iomapped memory space for qfprom security control space.
* @dev: qfprom device structure.
* @secclk: Clock supply.
* @vcc: Regulator supply.
* @soc_data: Data that for things that varies from SoC to SoC.
*/
struct qfprom_priv {
void __iomem *qfpraw;
void __iomem *qfpconf;
void __iomem *qfpcorrected;
void __iomem *qfpsecurity;
struct device *dev;
struct clk *secclk;
struct regulator *vcc;
const struct qfprom_soc_data *soc_data;
};
/**
* struct qfprom_touched_values - saved values to restore after blowing
*
* @clk_rate: The rate the clock was at before blowing.
* @accel_val: The value of the accel reg before blowing.
* @timer_val: The value of the timer before blowing.
*/
struct qfprom_touched_values {
unsigned long clk_rate;
u32 accel_val;
u32 timer_val;
};
/**
* struct qfprom_soc_compatible_data - Data matched against the SoC
* compatible string.
*
* @keepout: Array of keepout regions for this SoC.
* @nkeepout: Number of elements in the keepout array.
*/
struct qfprom_soc_compatible_data {
const struct nvmem_keepout *keepout;
unsigned int nkeepout;
};
static const struct nvmem_keepout sc7180_qfprom_keepout[] = {
{.start = 0x128, .end = 0x148},
{.start = 0x220, .end = 0x228}
};
static const struct qfprom_soc_compatible_data sc7180_qfprom = {
.keepout = sc7180_qfprom_keepout,
.nkeepout = ARRAY_SIZE(sc7180_qfprom_keepout)
};
static const struct nvmem_keepout sc7280_qfprom_keepout[] = {
{.start = 0x128, .end = 0x148},
{.start = 0x238, .end = 0x248}
};
static const struct qfprom_soc_compatible_data sc7280_qfprom = {
.keepout = sc7280_qfprom_keepout,
.nkeepout = ARRAY_SIZE(sc7280_qfprom_keepout)
};
/**
* qfprom_disable_fuse_blowing() - Undo enabling of fuse blowing.
* @priv: Our driver data.
* @old: The data that was stashed from before fuse blowing.
*
* Resets the value of the blow timer, accel register and the clock
* and voltage settings.
*
* Prints messages if there are errors but doesn't return an error code
* since there's not much we can do upon failure.
*/
static void qfprom_disable_fuse_blowing(const struct qfprom_priv *priv,
const struct qfprom_touched_values *old)
{
int ret;
writel(old->timer_val, priv->qfpconf + QFPROM_BLOW_TIMER_OFFSET);
writel(old->accel_val, priv->qfpconf + QFPROM_ACCEL_OFFSET);
dev_pm_genpd_set_performance_state(priv->dev, 0);
pm_runtime_put(priv->dev);
/*
* This may be a shared rail and may be able to run at a lower rate
* when we're not blowing fuses. At the moment, the regulator framework
* applies voltage constraints even on disabled rails, so remove our
* constraints and allow the rail to be adjusted by other users.
*/
ret = regulator_set_voltage(priv->vcc, 0, INT_MAX);
if (ret)
dev_warn(priv->dev, "Failed to set 0 voltage (ignoring)\n");
ret = regulator_disable(priv->vcc);
if (ret)
dev_warn(priv->dev, "Failed to disable regulator (ignoring)\n");
ret = clk_set_rate(priv->secclk, old->clk_rate);
if (ret)
dev_warn(priv->dev,
"Failed to set clock rate for disable (ignoring)\n");
clk_disable_unprepare(priv->secclk);
}
/**
* qfprom_enable_fuse_blowing() - Enable fuse blowing.
* @priv: Our driver data.
* @old: We'll stash stuff here to use when disabling.
*
* Sets the value of the blow timer, accel register and the clock
* and voltage settings.
*
* Prints messages if there are errors so caller doesn't need to.
*
* Return: 0 or -err.
*/
static int qfprom_enable_fuse_blowing(const struct qfprom_priv *priv,
struct qfprom_touched_values *old)
{
int ret;
int qfprom_blow_uV = priv->soc_data->qfprom_blow_uV;
ret = clk_prepare_enable(priv->secclk);
if (ret) {
dev_err(priv->dev, "Failed to enable clock\n");
return ret;
}
old->clk_rate = clk_get_rate(priv->secclk);
ret = clk_set_rate(priv->secclk, priv->soc_data->qfprom_blow_set_freq);
if (ret) {
dev_err(priv->dev, "Failed to set clock rate for enable\n");
goto err_clk_prepared;
}
/*
* Hardware requires a minimum voltage for fuse blowing.
* This may be a shared rail so don't specify a maximum.
* Regulator constraints will cap to the actual maximum.
*/
ret = regulator_set_voltage(priv->vcc, qfprom_blow_uV, INT_MAX);
if (ret) {
dev_err(priv->dev, "Failed to set %duV\n", qfprom_blow_uV);
goto err_clk_rate_set;
}
ret = regulator_enable(priv->vcc);
if (ret) {
dev_err(priv->dev, "Failed to enable regulator\n");
goto err_clk_rate_set;
}
ret = pm_runtime_get_sync(priv->dev);
if (ret < 0) {
pm_runtime_put_noidle(priv->dev);
dev_err(priv->dev, "Failed to enable power-domain\n");
goto err_reg_enable;
}
dev_pm_genpd_set_performance_state(priv->dev, INT_MAX);
old->timer_val = readl(priv->qfpconf + QFPROM_BLOW_TIMER_OFFSET);
old->accel_val = readl(priv->qfpconf + QFPROM_ACCEL_OFFSET);
writel(priv->soc_data->qfprom_blow_timer_value,
priv->qfpconf + QFPROM_BLOW_TIMER_OFFSET);
writel(priv->soc_data->accel_value,
priv->qfpconf + QFPROM_ACCEL_OFFSET);
return 0;
err_reg_enable:
regulator_disable(priv->vcc);
err_clk_rate_set:
clk_set_rate(priv->secclk, old->clk_rate);
err_clk_prepared:
clk_disable_unprepare(priv->secclk);
return ret;
}
/**
* qfprom_reg_write() - Write to fuses.
* @context: Our driver data.
* @reg: The offset to write at.
* @_val: Pointer to data to write.
* @bytes: The number of bytes to write.
*
* Writes to fuses. WARNING: THIS IS PERMANENT.
*
* Return: 0 or -err.
*/
static int qfprom_reg_write(void *context, unsigned int reg, void *_val,
size_t bytes)
{
struct qfprom_priv *priv = context;
struct qfprom_touched_values old;
int words = bytes / 4;
u32 *value = _val;
u32 blow_status;
int ret;
int i;
dev_dbg(priv->dev,
"Writing to raw qfprom region : %#010x of size: %zu\n",
reg, bytes);
/*
* The hardware only allows us to write word at a time, but we can
* read byte at a time. Until the nvmem framework allows a separate
* word_size and stride for reading vs. writing, we'll enforce here.
*/
if (bytes % 4) {
dev_err(priv->dev,
"%zu is not an integral number of words\n", bytes);
return -EINVAL;
}
if (reg % 4) {
dev_err(priv->dev,
"Invalid offset: %#x. Must be word aligned\n", reg);
return -EINVAL;
}
ret = qfprom_enable_fuse_blowing(priv, &old);
if (ret)
return ret;
ret = readl_relaxed_poll_timeout(
priv->qfpconf + QFPROM_BLOW_STATUS_OFFSET,
blow_status, blow_status == QFPROM_BLOW_STATUS_READY,
QFPROM_FUSE_BLOW_POLL_US, QFPROM_FUSE_BLOW_TIMEOUT_US);
if (ret) {
dev_err(priv->dev,
"Timeout waiting for initial ready; aborting.\n");
goto exit_enabled_fuse_blowing;
}
for (i = 0; i < words; i++)
writel(value[i], priv->qfpraw + reg + (i * 4));
ret = readl_relaxed_poll_timeout(
priv->qfpconf + QFPROM_BLOW_STATUS_OFFSET,
blow_status, blow_status == QFPROM_BLOW_STATUS_READY,
QFPROM_FUSE_BLOW_POLL_US, QFPROM_FUSE_BLOW_TIMEOUT_US);
/* Give an error, but not much we can do in this case */
if (ret)
dev_err(priv->dev, "Timeout waiting for finish.\n");
exit_enabled_fuse_blowing:
qfprom_disable_fuse_blowing(priv, &old);
return ret;
}
static int qfprom_reg_read(void *context,
unsigned int reg, void *_val, size_t bytes)
{
struct qfprom_priv *priv = context;
u8 *val = _val;
int i = 0, words = bytes;
void __iomem *base = priv->qfpcorrected;
if (read_raw_data && priv->qfpraw)
base = priv->qfpraw;
while (words--)
*val++ = readb(base + reg + i++);
return 0;
}
static void qfprom_runtime_disable(void *data)
{
pm_runtime_disable(data);
}
static const struct qfprom_soc_data qfprom_7_8_data = {
.accel_value = 0xD10,
.qfprom_blow_timer_value = 25,
.qfprom_blow_set_freq = 4800000,
.qfprom_blow_uV = 1800000,
};
static const struct qfprom_soc_data qfprom_7_15_data = {
.accel_value = 0xD08,
.qfprom_blow_timer_value = 24,
.qfprom_blow_set_freq = 4800000,
.qfprom_blow_uV = 1900000,
};
static int qfprom_probe(struct platform_device *pdev)
{
struct nvmem_config econfig = {
.name = "qfprom",
.stride = 1,
.word_size = 1,
.id = NVMEM_DEVID_AUTO,
.reg_read = qfprom_reg_read,
};
struct device *dev = &pdev->dev;
struct resource *res;
struct nvmem_device *nvmem;
const struct qfprom_soc_compatible_data *soc_data;
struct qfprom_priv *priv;
int ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
/* The corrected section is always provided */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->qfpcorrected = devm_ioremap_resource(dev, res);
if (IS_ERR(priv->qfpcorrected))
return PTR_ERR(priv->qfpcorrected);
econfig.size = resource_size(res);
econfig.dev = dev;
econfig.priv = priv;
priv->dev = dev;
soc_data = device_get_match_data(dev);
if (soc_data) {
econfig.keepout = soc_data->keepout;
econfig.nkeepout = soc_data->nkeepout;
}
/*
* If more than one region is provided then the OS has the ability
* to write.
*/
res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (res) {
u32 version;
int major_version, minor_version;
priv->qfpraw = devm_ioremap_resource(dev, res);
if (IS_ERR(priv->qfpraw))
return PTR_ERR(priv->qfpraw);
res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
priv->qfpconf = devm_ioremap_resource(dev, res);
if (IS_ERR(priv->qfpconf))
return PTR_ERR(priv->qfpconf);
res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
priv->qfpsecurity = devm_ioremap_resource(dev, res);
if (IS_ERR(priv->qfpsecurity))
return PTR_ERR(priv->qfpsecurity);
version = readl(priv->qfpsecurity + QFPROM_VERSION_OFFSET);
major_version = (version & QFPROM_MAJOR_VERSION_MASK) >>
QFPROM_MAJOR_VERSION_SHIFT;
minor_version = (version & QFPROM_MINOR_VERSION_MASK) >>
QFPROM_MINOR_VERSION_SHIFT;
if (major_version == 7 && minor_version == 8)
priv->soc_data = &qfprom_7_8_data;
else if (major_version == 7 && minor_version == 15)
priv->soc_data = &qfprom_7_15_data;
priv->vcc = devm_regulator_get(&pdev->dev, "vcc");
if (IS_ERR(priv->vcc))
return PTR_ERR(priv->vcc);
priv->secclk = devm_clk_get(dev, "core");
if (IS_ERR(priv->secclk)) {
ret = PTR_ERR(priv->secclk);
if (ret != -EPROBE_DEFER)
dev_err(dev, "Error getting clock: %d\n", ret);
return ret;
}
/* Only enable writing if we have SoC data. */
if (priv->soc_data)
econfig.reg_write = qfprom_reg_write;
}
pm_runtime_enable(dev);
ret = devm_add_action_or_reset(dev, qfprom_runtime_disable, dev);
if (ret)
return ret;
nvmem = devm_nvmem_register(dev, &econfig);
return PTR_ERR_OR_ZERO(nvmem);
}
static const struct of_device_id qfprom_of_match[] = {
{ .compatible = "qcom,qfprom",},
{ .compatible = "qcom,sc7180-qfprom", .data = &sc7180_qfprom},
{ .compatible = "qcom,sc7280-qfprom", .data = &sc7280_qfprom},
{/* sentinel */},
};
MODULE_DEVICE_TABLE(of, qfprom_of_match);
static struct platform_driver qfprom_driver = {
.probe = qfprom_probe,
.driver = {
.name = "qcom,qfprom",
.of_match_table = qfprom_of_match,
},
};
module_platform_driver(qfprom_driver);
MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org>");
MODULE_DESCRIPTION("Qualcomm QFPROM driver");
MODULE_LICENSE("GPL v2");