2020-10-16 20:07:48

by Evan Green

Subject: [PATCH v2 4/4] nvmem: qfprom: Don't touch certain fuses

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, and the newly introduced
nvmem keepout support to attach the set of regions
we should not access.

Signed-off-by: Evan Green <[email protected]>
---

Changes in v2:
- Use new core support in qfprom (Srini)

drivers/nvmem/qfprom.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)

diff --git a/drivers/nvmem/qfprom.c b/drivers/nvmem/qfprom.c
index 5e9e60e2e591d..6cace24dfbf73 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 */
@@ -88,6 +89,28 @@ struct qfprom_touched_values {
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)
+};
+
/**
* qfprom_disable_fuse_blowing() - Undo enabling of fuse blowing.
* @priv: Our driver data.
@@ -281,6 +304,7 @@ static int qfprom_probe(struct platform_device *pdev)
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;

@@ -299,6 +323,11 @@ static int qfprom_probe(struct platform_device *pdev)
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
@@ -354,6 +383,7 @@ 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);
--
2.26.2

2020-10-22 07:25:33

by Doug Anderson

Subject: Re: [PATCH v2 4/4] nvmem: qfprom: Don't touch certain fuses

Hi,

On Fri, Oct 16, 2020 at 12:27 PM Evan Green <[email protected]> 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, and the newly introduced
> nvmem keepout support to attach the set of regions
> we should not access.
>
> Signed-off-by: Evan Green <[email protected]>
> ---
>
> Changes in v2:
> - Use new core support in qfprom (Srini)
>
> drivers/nvmem/qfprom.c | 30 ++++++++++++++++++++++++++++++
> 1 file changed, 30 insertions(+)

Reviewed-by: Douglas Anderson <[email protected]>