[PATCH v2 1/3] nvmem: stm32: move STM32MP15_BSEC_NUM_LOWER in config

From: Patrick Delaunay
Date: Mon Oct 17 2022 - 11:50:57 EST


Support STM32MP15_BSEC_NUM_LOWER in stm32 romem config to prepare
the next SoC in STM32MP family.

Signed-off-by: Patrick Delaunay <patrick.delaunay@xxxxxxxxxxx>
---

Changes in v2:
- Add patch "move STM32MP15_BSEC_NUM_LOWER in config" in the serie,
solve dependency issue for "priv->lower" in patch "nvmem: stm32:
add warning when upper OTPs are updated"

drivers/nvmem/stm32-romem.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/nvmem/stm32-romem.c b/drivers/nvmem/stm32-romem.c
index 354be526897f..d93baee01d7b 100644
--- a/drivers/nvmem/stm32-romem.c
+++ b/drivers/nvmem/stm32-romem.c
@@ -22,16 +22,15 @@
/* shadow registers offest */
#define STM32MP15_BSEC_DATA0 0x200

-/* 32 (x 32-bits) lower shadow registers */
-#define STM32MP15_BSEC_NUM_LOWER 32
-
struct stm32_romem_cfg {
int size;
+ u8 lower;
};

struct stm32_romem_priv {
void __iomem *base;
struct nvmem_config cfg;
+ u8 lower;
};

static int stm32_romem_read(void *context, unsigned int offset, void *buf,
@@ -85,7 +84,7 @@ static int stm32_bsec_read(void *context, unsigned int offset, void *buf,
for (i = roffset; (i < roffset + rbytes); i += 4) {
u32 otp = i >> 2;

- if (otp < STM32MP15_BSEC_NUM_LOWER) {
+ if (otp < priv->lower) {
/* read lower data from shadow registers */
val = readl_relaxed(
priv->base + STM32MP15_BSEC_DATA0 + i);
@@ -159,6 +158,8 @@ static int stm32_romem_probe(struct platform_device *pdev)
priv->cfg.priv = priv;
priv->cfg.owner = THIS_MODULE;

+ priv->lower = 0;
+
cfg = (const struct stm32_romem_cfg *)
of_match_device(dev->driver->of_match_table, dev)->data;
if (!cfg) {
@@ -167,6 +168,7 @@ static int stm32_romem_probe(struct platform_device *pdev)
priv->cfg.reg_read = stm32_romem_read;
} else {
priv->cfg.size = cfg->size;
+ priv->lower = cfg->lower;
priv->cfg.reg_read = stm32_bsec_read;
priv->cfg.reg_write = stm32_bsec_write;
}
@@ -174,8 +176,17 @@ static int stm32_romem_probe(struct platform_device *pdev)
return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &priv->cfg));
}

+/*
+ * STM32MP15 BSEC OTP regions: 4096 OTP bits (with 3072 effective bits)
+ * => 96 x 32-bits data words
+ * - Lower: 1K bits, 2:1 redundancy, incremental bit programming
+ * => 32 (x 32-bits) lower shadow registers = words 0 to 31
+ * - Upper: 2K bits, ECC protection, word programming only
+ * => 64 (x 32-bits) = words 32 to 95
+ */
static const struct stm32_romem_cfg stm32mp15_bsec_cfg = {
- .size = 384, /* 96 x 32-bits data words */
+ .size = 384,
+ .lower = 32,
};

static const struct of_device_id stm32_romem_of_match[] = {
--
2.25.1