Re: [PATCH v4 1/2] soc: samsung: exynos-pmu: Add regmap support for SoCs that protect PMU regs
From: Sam Protsenko <semen.protsenko@linaro.org>
Date: 2024-02-09 20:51:00
Also in:
linux-samsung-soc, linux-watchdog, lkml
On Thu, Feb 8, 2024 at 10:21 AM Peter Griffin [off-list ref] wrote:
Some Exynos based SoCs like Tensor gs101 protect the PMU registers for security hardening reasons so that they are only write accessible in el3 via an SMC call. As most Exynos drivers that need to write PMU registers currently obtain a regmap via syscon (phys, pinctrl, watchdog). Support for the above usecase is implemented in this driver using a custom regmap similar to syscon to handle the SMC call. Platforms that don't secure PMU registers, get a mmio regmap like before. As regmaps abstract out the underlying register access changes to the leaf drivers are minimal. A new API exynos_get_pmu_regmap_by_phandle() is provided for leaf drivers that currently use syscon_regmap_lookup_by_phandle(). This also handles deferred probing. Signed-off-by: Peter Griffin <peter.griffin@linaro.org> --- Changes since v3: - Fix PMUALIVE_MASK - Add TENSOR_ prefix - clear SET_BITS bits on each loop iteration - change set_bit to set_bits in func name - Fix some alignment - Add missing return on dev_err_probe - Reduce indentation in loop Changes since v2 - Add select REGMAP to Kconfig - Add constant for SET/CLEAR bits - Replace kerneldoc with one line comment - Fix kerneldoc for EXPORT_SYMBOL_GPL funcs - remove superfluous extern keyword - dev_err_probe() on probe error - shorten regmcfg name - no compatibles inside probe, use match data - don't mix declarations with/without initializations - tensor_sec_reg_read() use mmio to avoid access restrictions - Collect up Reviewed-by - const for regmap_config structs ---
Tested-by: Sam Protsenko <semen.protsenko@linaro.org> Tested on my E850-96. All modules that use PMU are still functional with this patch (watchdog, USB host and Ethernet). No regressions. [snip] _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel