Messages in this thread | | | Subject | Re: [PATCH 3/3] nvmem: qfprom: Don't touch certain fuses | From | Srinivas Kandagatla <> | Date | Thu, 1 Oct 2020 15:17:09 +0100 |
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Hi Evan,
On 29/09/2020 21:58, Evan Green wrote: > Some fuse ranges are protected by the XPU such that the AP cannot > access them. Attempting to do so causes an SError. Use the newly > introduced per-soc compatible string to attach the set of regions > we should not access. Then tiptoe around those regions. >
This is a generic feature that can be used by any nvmem provider, can you move this logic to nvmem core instead of having it in qfprom!
thanks, srini
> Signed-off-by: Evan Green <evgreen@chromium.org> > --- > > drivers/nvmem/qfprom.c | 55 +++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 51 insertions(+), 4 deletions(-) > > diff --git a/drivers/nvmem/qfprom.c b/drivers/nvmem/qfprom.c > index 5e9e60e2e591d..feea39ae52164 100644 > --- a/drivers/nvmem/qfprom.c > +++ b/drivers/nvmem/qfprom.c > @@ -12,6 +12,7 @@ > #include <linux/mod_devicetable.h> > #include <linux/nvmem-provider.h> > #include <linux/platform_device.h> > +#include <linux/property.h> > #include <linux/regulator/consumer.h> > > /* Blow timer clock frequency in Mhz */ > @@ -51,6 +52,17 @@ struct qfprom_soc_data { > u32 qfprom_blow_set_freq; > }; > > +/** > + * struct qfprom_keepout_region - registers to avoid touching. > + * > + * @start: The first byte offset to avoid. > + * @end: One after the last byte offset to avoid. > + */ > +struct qfprom_keepout_region { > + u32 start; > + u32 end; > +}; > + > /** > * struct qfprom_priv - structure holding qfprom attributes > * > @@ -63,6 +75,7 @@ struct qfprom_soc_data { > * @secclk: Clock supply. > * @vcc: Regulator supply. > * @soc_data: Data that for things that varies from SoC to SoC. > + * @keepout: Fuse regions not to access, as they may cause SErrors. > */ > struct qfprom_priv { > void __iomem *qfpraw; > @@ -73,6 +86,7 @@ struct qfprom_priv { > struct clk *secclk; > struct regulator *vcc; > const struct qfprom_soc_data *soc_data; > + const struct qfprom_keepout_region *keepout; > }; > > /** > @@ -88,6 +102,12 @@ struct qfprom_touched_values { > u32 timer_val; > }; > > +const struct qfprom_keepout_region sc7180_qfprom[] = { > + {.start = 0x128, .end = 0x148}, > + {.start = 0x220, .end = 0x228}, > + {} /* Sentinal where start == end. */ > +}; > + > /** > * qfprom_disable_fuse_blowing() - Undo enabling of fuse blowing. > * @priv: Our driver data. > @@ -171,6 +191,23 @@ static int qfprom_enable_fuse_blowing(const struct qfprom_priv *priv, > return ret; > } > > +static int qfprom_check_reg(struct qfprom_priv *priv, unsigned int reg) > +{ > + const struct qfprom_keepout_region *keepout = priv->keepout; > + > + if (!keepout) > + return 1; > + > + while (keepout->start != keepout->end) { > + if ((reg >= keepout->start) && (reg < keepout->end)) > + return 0; > + > + keepout++; > + } > + > + return 1; > +} > + > /** > * qfprom_efuse_reg_write() - Write to fuses. > * @context: Our driver data. > @@ -228,8 +265,10 @@ static int qfprom_reg_write(void *context, unsigned int reg, void *_val, > goto exit_enabled_fuse_blowing; > } > > - for (i = 0; i < words; i++) > - writel(value[i], priv->qfpraw + reg + (i * 4)); > + for (i = 0; i < words; i++) { > + if (qfprom_check_reg(priv, reg + (i * 4))) > + writel(value[i], priv->qfpraw + reg + (i * 4)); > + } > > ret = readl_relaxed_poll_timeout( > priv->qfpconf + QFPROM_BLOW_STATUS_OFFSET, > @@ -257,8 +296,14 @@ static int qfprom_reg_read(void *context, > if (read_raw_data && priv->qfpraw) > base = priv->qfpraw; > > - while (words--) > - *val++ = readb(base + reg + i++); > + while (words--) { > + if (qfprom_check_reg(priv, reg + i)) > + *val++ = readb(base + reg + i); > + else > + *val++ = 0; > + > + i++; > + } > > return 0; > } > @@ -299,6 +344,7 @@ static int qfprom_probe(struct platform_device *pdev) > econfig.priv = priv; > > priv->dev = dev; > + priv->keepout = device_get_match_data(dev); > > /* > * If more than one region is provided then the OS has the ability > @@ -354,6 +400,7 @@ static int qfprom_probe(struct platform_device *pdev) > > static const struct of_device_id qfprom_of_match[] = { > { .compatible = "qcom,qfprom",}, > + { .compatible = "qcom,sc7180-qfprom", .data = &sc7180_qfprom}, > {/* sentinel */}, > }; > MODULE_DEVICE_TABLE(of, qfprom_of_match); >
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