korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-30 15:44:13 +08:00
Code Issues Packages Projects Releases Wiki Activity

hwrng: stm32 - rework power management sequences

Browse Source 
Implement stm32_rng_suspend()/stm32_rng_resume() low-power APIs
called when the hardware block context will be lost.

There is no need to save the RNG_CR register in
stm32_rng_runtime_suspend() as the context is not lost. Therefore,
only enable/disable the RNG in the runtime sequences.

Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Gatien Chevallier 2023-09-21 10:03:00 +02:00 committed by Herbert Xu
parent a1b03e7ade
commit ff4e46104f
1 changed files with 97 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

108
drivers/char/hw_random/stm32-rng.c
View File

@ -55,11 +55,25 @@ struct stm32_rng_data {
bool has_cond_reset;
};
/**
* struct stm32_rng_config - RNG configuration data
*
* @cr: RNG configuration. 0 means default hardware RNG configuration
* @nscr: Noise sources control configuration.
* @htcr: Health tests configuration.
*/
struct stm32_rng_config {
u32 cr;
u32 nscr;
u32 htcr;
};
struct stm32_rng_private {
struct hwrng rng;
void __iomem *base;
struct clk *clk;
struct reset_control *rst;
struct stm32_rng_config pm_conf;
const struct stm32_rng_data *data;
bool ced;
bool lock_conf;
@ -355,11 +369,10 @@ static int stm32_rng_remove(struct platform_device *ofdev)
return 0;
}
#ifdef CONFIG_PM
static int stm32_rng_runtime_suspend(struct device *dev)
static int __maybe_unused stm32_rng_runtime_suspend(struct device *dev)
{
u32 reg;
struct stm32_rng_private *priv = dev_get_drvdata(dev);
u32 reg;
reg = readl_relaxed(priv->base + RNG_CR);
reg &= ~RNG_CR_RNGEN;
@ -369,25 +382,98 @@ static int stm32_rng_runtime_suspend(struct device *dev)
return 0;
}
static int stm32_rng_runtime_resume(struct device *dev)
static int __maybe_unused stm32_rng_suspend(struct device *dev)
{
u32 reg;
struct stm32_rng_private *priv = dev_get_drvdata(dev);
clk_prepare_enable(priv->clk);
if (priv->data->has_cond_reset) {
priv->pm_conf.nscr = readl_relaxed(priv->base + RNG_NSCR);
priv->pm_conf.htcr = readl_relaxed(priv->base + RNG_HTCR);
}
/* Do not save that RNG is enabled as it will be handled at resume */
priv->pm_conf.cr = readl_relaxed(priv->base + RNG_CR) & ~RNG_CR_RNGEN;
writel_relaxed(priv->pm_conf.cr, priv->base + RNG_CR);
clk_disable_unprepare(priv->clk);
return 0;
}
static int __maybe_unused stm32_rng_runtime_resume(struct device *dev)
{
struct stm32_rng_private *priv = dev_get_drvdata(dev);
int err;
u32 reg;
err = clk_prepare_enable(priv->clk);
if (err)
return err;
/* Clean error indications */
writel_relaxed(0, priv->base + RNG_SR);
reg = readl_relaxed(priv->base + RNG_CR);
reg |= RNG_CR_RNGEN;
writel_relaxed(reg, priv->base + RNG_CR);
return 0;
}
#endif
static const struct dev_pm_ops stm32_rng_pm_ops = {
static int __maybe_unused stm32_rng_resume(struct device *dev)
{
struct stm32_rng_private *priv = dev_get_drvdata(dev);
int err;
u32 reg;
err = clk_prepare_enable(priv->clk);
if (err)
return err;
/* Clean error indications */
writel_relaxed(0, priv->base + RNG_SR);
if (priv->data->has_cond_reset) {
/*
* Correct configuration in bits [29:4] must be set in the same
* access that set RNG_CR_CONDRST bit. Else config setting is
* not taken into account. CONFIGLOCK bit must also be unset but
* it is not handled at the moment.
*/
writel_relaxed(priv->pm_conf.cr | RNG_CR_CONDRST, priv->base + RNG_CR);
writel_relaxed(priv->pm_conf.nscr, priv->base + RNG_NSCR);
writel_relaxed(priv->pm_conf.htcr, priv->base + RNG_HTCR);
reg = readl_relaxed(priv->base + RNG_CR);
reg |= RNG_CR_RNGEN;
reg &= ~RNG_CR_CONDRST;
writel_relaxed(reg, priv->base + RNG_CR);
err = readl_relaxed_poll_timeout_atomic(priv->base + RNG_CR, reg,
reg & ~RNG_CR_CONDRST, 10, 100000);
if (err) {
clk_disable_unprepare(priv->clk);
dev_err((struct device *)priv->rng.priv,
"%s: timeout:%x CR: %x!\n", __func__, err, reg);
return -EINVAL;
}
} else {
reg = priv->pm_conf.cr;
reg |= RNG_CR_RNGEN;
writel_relaxed(reg, priv->base + RNG_CR);
}
return 0;
}
static const struct dev_pm_ops __maybe_unused stm32_rng_pm_ops = {
SET_RUNTIME_PM_OPS(stm32_rng_runtime_suspend,
stm32_rng_runtime_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
pm_runtime_force_resume)
SET_SYSTEM_SLEEP_PM_OPS(stm32_rng_suspend,
stm32_rng_resume)
};
static const struct stm32_rng_data stm32mp13_rng_data = {
@ -467,7 +553,7 @@ static int stm32_rng_probe(struct platform_device *ofdev)
static struct platform_driver stm32_rng_driver = {
.driver = {
.name = "stm32-rng",
.pm = &stm32_rng_pm_ops,
.pm = pm_ptr(&stm32_rng_pm_ops),
.of_match_table = stm32_rng_match,
},
.probe = stm32_rng_probe,