On 6/2/21 6:23 AM, Anup Patel wrote:
> The RISC-V SBI HSM extension provides HSM suspend call which can
> be used by Linux RISC-V to enter platform specific low-power state.
>
> This patch adds a CPU idle driver based on RISC-V SBI calls which
> will populate idle states from device tree and use SBI calls to
> entry these idle states.
>
> Signed-off-by: Anup Patel <anup.patel@xxxxxxx>
> ---
> MAINTAINERS | 7 +
> drivers/cpuidle/Kconfig | 5 +
> drivers/cpuidle/Kconfig.riscv | 15 +
> drivers/cpuidle/Makefile | 4 +
> drivers/cpuidle/cpuidle-sbi.c | 626 ++++++++++++++++++++++++++++++++++
> 5 files changed, 657 insertions(+)
> create mode 100644 drivers/cpuidle/Kconfig.riscv
> create mode 100644 drivers/cpuidle/cpuidle-sbi.c
>
> ...
> diff --git a/drivers/cpuidle/cpuidle-sbi.c b/drivers/cpuidle/cpuidle-sbi.c
> new file mode 100644
> index 000000000000..f743684d07de
> --- /dev/null
> +++ b/drivers/cpuidle/cpuidle-sbi.c
> @@ -0,0 +1,626 @@
> ...
> + /* Initialize idle states from DT. */
> + ret = sbi_cpuidle_dt_init_states(dev, drv, cpu, state_count);
> + if (ret) {
> + pr_err("HART%ld: failed to init idle states\n",
> + cpuid_to_hartid_map(cpu));
> + return ret;
> + }
> +
> + ret = cpuidle_register(drv, NULL);
> + if (ret)
> + goto deinit;
> +
> + cpuidle_cooling_register(drv);
> +
> + return 0;
> +deinit:
> + sbi_cpuidle_deinit_cpu(cpu);
> + return ret;
> +}
> +
> +static int sbi_cpuidle_pd_power_off(struct generic_pm_domain *pd)
This function should be moved inside the CONFIG_DT_IDLE_GENPD block
below. Otherwise it is defined but unused.
> +{
> + struct genpd_power_state *state = &pd->states[pd->state_idx];
> + u32 *pd_state;
> +
> + if (!state->data)
> + return 0;
> +
> + if (!sbi_cpuidle_pd_allow_domain_state)
> + return -EBUSY;
> +
> + /* OSI mode is enabled, set the corresponding domain state. */
> + pd_state = state->data;
> + sbi_set_domain_state(*pd_state);
> +
> + return 0;
> +}
> +
> +static void sbi_cpuidle_domain_sync_state(struct device *dev)
> +{
> + /*
> + * All devices have now been attached/probed to the PM domain
> + * topology, hence it's fine to allow domain states to be picked.
> + */
> + sbi_cpuidle_pd_allow_domain_state = true;
> +}
> +
> +#ifdef CONFIG_DT_IDLE_GENPD
> +
> +struct sbi_pd_provider {
> + struct list_head link;
> + struct device_node *node;
> +};
> +
> +static LIST_HEAD(sbi_pd_providers);
> +
> +static int sbi_pd_init(struct device_node *np)
> +{
> + struct generic_pm_domain *pd;
> + struct sbi_pd_provider *pd_provider;
> + struct dev_power_governor *pd_gov;
> + int ret = -ENOMEM, state_count = 0;
> +
> + pd = dt_idle_pd_alloc(np, sbi_dt_parse_state_node);
> + if (!pd)
> + goto out;
> ...
