| Message ID | 20230106180414.v5.3.I59210046e368cfc22bd3cca2afe1653674f8ece8@changeid (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | nvmem: stm32: add OP-TEE support for STM32MP13x | expand |
On Fri, 6 Jan 2023 at 18:04, Patrick Delaunay <patrick.delaunay@foss.st.com> wrote: > > 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> > --- > > Changes in v5: > - update the BSEC SMC detection logic in stm32_romem_probe() > after Etienne Carierre review to support NVMEM probe after OP-TEE probe > > Changes in v3: > - use of_find_compatible_node in optee_presence_check function > instead of of_find_node_by_path("/firmware/optee") > > Changes in v2: > - Added patch in the serie for BSEC PTA support on STM32MP15x > with dynamic detection of OP-TEE presence and SMC support (legacy mode) > > drivers/nvmem/stm32-romem.c | 38 +++++++++++++++++++++++++++++++++---- > 1 file changed, 34 insertions(+), 4 deletions(-) > > diff --git a/drivers/nvmem/stm32-romem.c b/drivers/nvmem/stm32-romem.c > index 978a63edf297..e0babc2cebd7 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 ready */ Nitpicking: I would replace "SMC not ready" with "SMC not supported". Aside that, Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org> > + 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); > -- > 2.25.1 >
diff --git a/drivers/nvmem/stm32-romem.c b/drivers/nvmem/stm32-romem.c index 978a63edf297..e0babc2cebd7 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 ready */ + 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);
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> --- Changes in v5: - update the BSEC SMC detection logic in stm32_romem_probe() after Etienne Carierre review to support NVMEM probe after OP-TEE probe Changes in v3: - use of_find_compatible_node in optee_presence_check function instead of of_find_node_by_path("/firmware/optee") Changes in v2: - Added patch in the serie for BSEC PTA support on STM32MP15x with dynamic detection of OP-TEE presence and SMC support (legacy mode) drivers/nvmem/stm32-romem.c | 38 +++++++++++++++++++++++++++++++++---- 1 file changed, 34 insertions(+), 4 deletions(-)