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author | Patrick Delaunay <patrick.delaunay@foss.st.com> | 2023-02-06 13:43:52 +0000 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-02-06 19:06:59 +0100 |
commit | df2f34ef1d924125ffaf29dfdaf7cdbd3183c321 (patch) | |
tree | 33ffdb4ea978b858f6d385bdaa817e19e0850274 /drivers/nvmem/stm32-romem.c | |
parent | 6a0bc3522e746025e2d9a63ab2cb5d7062c2d39c (diff) | |
download | linux-df2f34ef1d924125ffaf29dfdaf7cdbd3183c321.tar.gz linux-df2f34ef1d924125ffaf29dfdaf7cdbd3183c321.tar.bz2 linux-df2f34ef1d924125ffaf29dfdaf7cdbd3183c321.zip |
nvmem: stm32: detect bsec pta presence for STM32MP15x
On STM32MP15x SoC, the SMC backend is optional when OP-TEE is used;
the PTA BSEC should be used as it is done on STM32MP13x platform,
but the BSEC SMC can be also used: it is a legacy mode in OP-TEE,
not recommended but used in previous OP-TEE firmware.
The presence of OP-TEE is dynamically detected in STM32MP15x device tree
and the supported NVMEM backend is dynamically detected:
- PTA with stm32_bsec_pta_find
- SMC with stm32_bsec_check
With OP-TEE but without PTA and SMC detection, the probe is deferred for
STM32MP15x devices.
On STM32MP13x platform, only the PTA is supported with cfg->ta = true
and this detection is skipped.
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230206134356.839737-19-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/nvmem/stm32-romem.c')
-rw-r--r-- | drivers/nvmem/stm32-romem.c | 38 |
1 files changed, 34 insertions, 4 deletions
diff --git a/drivers/nvmem/stm32-romem.c b/drivers/nvmem/stm32-romem.c index 978a63edf297..ba779e26937a 100644 --- a/drivers/nvmem/stm32-romem.c +++ b/drivers/nvmem/stm32-romem.c @@ -159,6 +159,31 @@ static int stm32_bsec_pta_write(void *context, unsigned int offset, void *buf, return stm32_bsec_optee_ta_write(priv->ctx, priv->lower, offset, buf, bytes); } +static bool stm32_bsec_smc_check(void) +{ + u32 val; + int ret; + + /* check that the OP-TEE support the BSEC SMC (legacy mode) */ + ret = stm32_bsec_smc(STM32_SMC_READ_SHADOW, 0, 0, &val); + + return !ret; +} + +static bool optee_presence_check(void) +{ + struct device_node *np; + bool tee_detected = false; + + /* check that the OP-TEE node is present and available. */ + np = of_find_compatible_node(NULL, NULL, "linaro,optee-tz"); + if (np && of_device_is_available(np)) + tee_detected = true; + of_node_put(np); + + return tee_detected; +} + static int stm32_romem_probe(struct platform_device *pdev) { const struct stm32_romem_cfg *cfg; @@ -195,11 +220,16 @@ static int stm32_romem_probe(struct platform_device *pdev) } else { priv->cfg.size = cfg->size; priv->lower = cfg->lower; - if (cfg->ta) { + if (cfg->ta || optee_presence_check()) { rc = stm32_bsec_optee_ta_open(&priv->ctx); - /* wait for OP-TEE client driver to be up and ready */ - if (rc) - return rc; + if (rc) { + /* wait for OP-TEE client driver to be up and ready */ + if (rc == -EPROBE_DEFER) + return -EPROBE_DEFER; + /* BSEC PTA is required or SMC not supported */ + if (cfg->ta || !stm32_bsec_smc_check()) + return rc; + } } if (priv->ctx) { rc = devm_add_action_or_reset(dev, stm32_bsec_optee_ta_close, priv->ctx); |