[RFC v3 05/18] pmdomain: thead: Add power-domain driver for TH1520

Michal Wilczynski
2025-01-20T17:23:29Z

The T-Head TH1520 SoC contains multiple power islands that can be
programmatically turned on and off using the AON (Always-On) protocol
and a hardware mailbox [1]. The relevant mailbox driver has already been
merged into the mainline kernel in commit 5d4d263e1c6b ("mailbox:
Introduce support for T-head TH1520 Mailbox driver");

This commit introduces a power-domain driver for the TH1520 SoC, which
is using AON firmware protocol to communicate with E902 core through the
hardware mailbox. This way it can send power on/off commands to the E902
core.

Link: https://openbeagle.org/beaglev-ahead/beaglev-ahead/-/blob/main/docs/TH1520%20System%20User%20Manual.pdf [1]

Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>
---
MAINTAINERS | 1 +
drivers/pmdomain/Kconfig | 1 +
drivers/pmdomain/Makefile | 1 +
drivers/pmdomain/thead/Kconfig | 12 ++
drivers/pmdomain/thead/Makefile | 2 +
drivers/pmdomain/thead/th1520-pm-domains.c | 174 +++++++++++++++++++++
6 files changed, 191 insertions(+)
create mode 100644 drivers/pmdomain/thead/Kconfig
create mode 100644 drivers/pmdomain/thead/Makefile
create mode 100644 drivers/pmdomain/thead/th1520-pm-domains.c

diff --git a/MAINTAINERS b/MAINTAINERS
index c96a1e6c8831..363bb3471a33 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20195,6 +20195,7 @@ F: drivers/firmware/thead,th1520-aon.c
F: drivers/mailbox/mailbox-th1520.c
F: drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c
F: drivers/pinctrl/pinctrl-th1520.c
+F: drivers/pmdomain/thead/
F: include/dt-bindings/clock/thead,th1520-clk-ap.h
F: include/dt-bindings/firmware/thead,th1520-aon.h
F: include/linux/firmware/thead/thead,th1520-aon.h
diff --git a/drivers/pmdomain/Kconfig b/drivers/pmdomain/Kconfig
index 23c64851a5b0..91f04ace35d4 100644
--- a/drivers/pmdomain/Kconfig
+++ b/drivers/pmdomain/Kconfig
@@ -16,6 +16,7 @@ source "drivers/pmdomain/st/Kconfig"
source "drivers/pmdomain/starfive/Kconfig"
source "drivers/pmdomain/sunxi/Kconfig"
source "drivers/pmdomain/tegra/Kconfig"
+source "drivers/pmdomain/thead/Kconfig"
source "drivers/pmdomain/ti/Kconfig"
source "drivers/pmdomain/xilinx/Kconfig"

diff --git a/drivers/pmdomain/Makefile b/drivers/pmdomain/Makefile
index a68ece2f4c68..7030f44a49df 100644
--- a/drivers/pmdomain/Makefile
+++ b/drivers/pmdomain/Makefile
@@ -14,6 +14,7 @@ obj-y += st/
obj-y += starfive/
obj-y += sunxi/
obj-y += tegra/
+obj-y += thead/
obj-y += ti/
obj-y += xilinx/
obj-y += core.o governor.o
diff --git a/drivers/pmdomain/thead/Kconfig b/drivers/pmdomain/thead/Kconfig
new file mode 100644
index 000000000000..c7a1ac0c61dc
--- /dev/null
+++ b/drivers/pmdomain/thead/Kconfig
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config TH1520_PM_DOMAINS
+ tristate "Support TH1520 Power Domains"
+ depends on TH1520_AON_PROTOCOL || !TH1520_AON_PROTOCOL
+ select REGMAP_MMIO
+ help
+ This driver enables power domain management for the T-HEAD
+ TH-1520 SoC. On this SoC there are number of power domains,
+ which can be managed independently. For example GPU, NPU,
+ and DPU reside in their own power domains which can be
+ turned on/off.
diff --git a/drivers/pmdomain/thead/Makefile b/drivers/pmdomain/thead/Makefile
new file mode 100644
index 000000000000..adfdf5479c68
--- /dev/null
+++ b/drivers/pmdomain/thead/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_TH1520_PM_DOMAINS) += th1520-pm-domains.o
diff --git a/drivers/pmdomain/thead/th1520-pm-domains.c b/drivers/pmdomain/thead/th1520-pm-domains.c
new file mode 100644
index 000000000000..d913ad40fb76
--- /dev/null
+++ b/drivers/pmdomain/thead/th1520-pm-domains.c
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Alibaba Group Holding Limited.
+ * Copyright (c) 2024 Samsung Electronics Co., Ltd.
+ * Author: Michal Wilczynski <m.wilczynski@samsung.com>
+ */
+
+#include <linux/firmware/thead/thead,th1520-aon.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+
+#include <dt-bindings/firmware/thead,th1520-aon.h>
+
+struct th1520_power_domain {
+ struct th1520_aon_chan *aon_chan;
+ struct generic_pm_domain genpd;
+ u32 rsrc;
+};
+
+struct th1520_power_info {
+ const char *name;
+ u32 rsrc;
+};
+
+static const struct th1520_power_info th1520_pd_ranges[] = {
+ { "vdec", TH1520_AON_VDEC_PD },
+ { "npu", TH1520_AON_NPU_PD },
+ { "venc", TH1520_AON_VENC_PD },
+ { "gpu", TH1520_AON_GPU_PD },
+ { "dsp0", TH1520_AON_DSP0_PD },
+ { "dsp1", TH1520_AON_DSP1_PD }
+};
+
+static inline struct th1520_power_domain *
+to_th1520_power_domain(struct generic_pm_domain *genpd)
+{
+ return container_of(genpd, struct th1520_power_domain, genpd);
+}
+
+static int th1520_pd_power_on(struct generic_pm_domain *domain)
+{
+ struct th1520_power_domain *pd = to_th1520_power_domain(domain);
+
+ return th1520_aon_power_update(pd->aon_chan, pd->rsrc, true);
+}
+
+static int th1520_pd_power_off(struct generic_pm_domain *domain)
+{
+ struct th1520_power_domain *pd = to_th1520_power_domain(domain);
+
+ return th1520_aon_power_update(pd->aon_chan, pd->rsrc, false);
+}
+
+static struct generic_pm_domain *th1520_pd_xlate(const struct of_phandle_args *spec,
+ void *data)
+{
+ struct generic_pm_domain *domain = ERR_PTR(-ENOENT);
+ struct genpd_onecell_data *pd_data = data;
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(th1520_pd_ranges); i++) {
+ struct th1520_power_domain *pd;
+
+ pd = to_th1520_power_domain(pd_data->domains[i]);
+ if (pd->rsrc == spec->args[0]) {
+ domain = &pd->genpd;
+ break;
+ }
+ }
+
+ return domain;
+}
+
+static struct th1520_power_domain *
+th1520_add_pm_domain(struct device *dev, const struct th1520_power_info *pi)
+{
+ struct th1520_power_domain *pd;
+ int ret;
+
+ pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
+ if (!pd)
+ return ERR_PTR(-ENOMEM);
+
+ pd->rsrc = pi->rsrc;
+ pd->genpd.power_on = th1520_pd_power_on;
+ pd->genpd.power_off = th1520_pd_power_off;
+ pd->genpd.name = pi->name;
+
+ ret = pm_genpd_init(&pd->genpd, NULL, true);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return pd;
+}
+
+static void th1520_pd_init_all_off(struct generic_pm_domain **domains,
+ struct device *dev)
+{
+ int ret;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(th1520_pd_ranges); i++) {
+ struct th1520_power_domain *pd =
+ to_th1520_power_domain(domains[i]);
+
+ ret = th1520_aon_power_update(pd->aon_chan, pd->rsrc, false);
+ if (ret)
+ dev_err(dev,
+ "Failed to initially power down power domain %s\n",
+ pd->genpd.name);
+ }
+}
+
+static int th1520_pd_probe(struct platform_device *pdev)
+{
+ struct generic_pm_domain **domains;
+ struct genpd_onecell_data *pd_data;
+ struct th1520_aon_chan *aon_chan;
+ struct device *dev = &pdev->dev;
+ int i;
+
+ aon_chan = dev_get_drvdata(dev->parent);
+ if (!aon_chan) {
+ dev_err(dev, "Failed to get AON channel from parent\n");
+ return -EINVAL;
+ }
+
+ domains = devm_kcalloc(dev, ARRAY_SIZE(th1520_pd_ranges),
+ sizeof(*domains), GFP_KERNEL);
+ if (!domains)
+ return -ENOMEM;
+
+ pd_data = devm_kzalloc(dev, sizeof(*pd_data), GFP_KERNEL);
+ if (!pd_data)
+ return -ENOMEM;
+
+ for (i = 0; i < ARRAY_SIZE(th1520_pd_ranges); i++) {
+ struct th1520_power_domain *pd;
+
+ pd = th1520_add_pm_domain(dev, &th1520_pd_ranges[i]);
+ if (IS_ERR(pd))
+ return PTR_ERR(pd);
+
+ pd->aon_chan = aon_chan;
+ domains[i] = &pd->genpd;
+ dev_dbg(dev, "added power domain %s\n", pd->genpd.name);
+ }
+
+ pd_data->domains = domains;
+ pd_data->num_domains = ARRAY_SIZE(th1520_pd_ranges);
+ pd_data->xlate = th1520_pd_xlate;
+
+ /*
+ * Initialize all power domains to off to ensure they start in a
+ * low-power state. This allows device drivers to manage power
+ * domains by turning them on or off as needed.
+ */
+ th1520_pd_init_all_off(domains, dev);
+
+ return of_genpd_add_provider_onecell(dev->parent->of_node, pd_data);
+}
+
+static struct platform_driver th1520_pd_driver = {
+ .driver = {
+ .name = "th1520-pd",
+ },
+ .probe = th1520_pd_probe,
+};
+module_platform_driver(th1520_pd_driver);
+
+MODULE_AUTHOR("Michal Wilczynski <m.wilczynski@samsung.com>");
+MODULE_DESCRIPTION("T-HEAD TH1520 SoC power domain controller");
+MODULE_LICENSE("GPL");
--
2.34.1