This type of bus is used in Linux to designate buses which have power domains and/or clocks which need to be enabled before their child devices can be used. Because power domains are automatically enabled before probing in U-Boot, we just need to enable any clocks present.
Signed-off-by: Sean Anderson seanga2@gmail.com Reviewed-by: Simon Glass sjg@chromium.org ---
Changes in v5: - Reorder includes (simple pm)
Changes in v4: - Split the bus off into its own driver - Add test - Fix line spacing in Kconfig - Lint
Changes in v3: - New
arch/sandbox/dts/test.dts | 6 ++ arch/sandbox/include/asm/clk.h | 1 + configs/sandbox_defconfig | 1 + .../bus/simple-pm-bus.txt | 44 +++++++++++++++ drivers/core/Kconfig | 7 +++ drivers/core/Makefile | 1 + drivers/core/simple-pm-bus.c | 56 +++++++++++++++++++ test/dm/Makefile | 1 + test/dm/simple-pm-bus.c | 45 +++++++++++++++ 9 files changed, 162 insertions(+) create mode 100644 doc/device-tree-bindings/bus/simple-pm-bus.txt create mode 100644 drivers/core/simple-pm-bus.c create mode 100644 test/dm/simple-pm-bus.c
diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts index 4a277934a7..96e0b55eed 100644 --- a/arch/sandbox/dts/test.dts +++ b/arch/sandbox/dts/test.dts @@ -934,6 +934,12 @@ mdio: mdio-test { compatible = "sandbox,mdio"; }; + + pm-bus-test { + compatible = "simple-pm-bus"; + clocks = <&clk_sandbox 4>; + power-domains = <&pwrdom 1>; + }; };
#include "sandbox_pmic.dtsi" diff --git a/arch/sandbox/include/asm/clk.h b/arch/sandbox/include/asm/clk.h index 1573e4a134..c184c4bffc 100644 --- a/arch/sandbox/include/asm/clk.h +++ b/arch/sandbox/include/asm/clk.h @@ -21,6 +21,7 @@ enum sandbox_clk_id { SANDBOX_CLK_ID_I2C, SANDBOX_CLK_ID_UART1, SANDBOX_CLK_ID_UART2, + SANDBOX_CLK_ID_BUS,
SANDBOX_CLK_ID_COUNT, }; diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig index 7b02b8de7c..22c1a073c4 100644 --- a/configs/sandbox_defconfig +++ b/configs/sandbox_defconfig @@ -90,6 +90,7 @@ CONFIG_REGMAP=y CONFIG_SYSCON=y CONFIG_DEVRES=y CONFIG_DEBUG_DEVRES=y +CONFIG_SIMPLE_PM_BUS=y CONFIG_ADC=y CONFIG_ADC_SANDBOX=y CONFIG_AXI=y diff --git a/doc/device-tree-bindings/bus/simple-pm-bus.txt b/doc/device-tree-bindings/bus/simple-pm-bus.txt new file mode 100644 index 0000000000..6f15037131 --- /dev/null +++ b/doc/device-tree-bindings/bus/simple-pm-bus.txt @@ -0,0 +1,44 @@ +Simple Power-Managed Bus +======================== + +A Simple Power-Managed Bus is a transparent bus that doesn't need a real +driver, as it's typically initialized by the boot loader. + +However, its bus controller is part of a PM domain, or under the control of a +functional clock. Hence, the bus controller's PM domain and/or clock must be +enabled for child devices connected to the bus (either on-SoC or externally) +to function. + +While "simple-pm-bus" follows the "simple-bus" set of properties, as specified +in the Devicetree Specification, it is not an extension of "simple-bus". + + +Required properties: + - compatible: Must contain at least "simple-pm-bus". + Must not contain "simple-bus". + It's recommended to let this be preceded by one or more + vendor-specific compatible values. + - #address-cells, #size-cells, ranges: Must describe the mapping between + parent address and child address spaces. + +Optional platform-specific properties for clock or PM domain control (at least +one of them is required): + - clocks: Must contain a reference to the functional clock(s), + - power-domains: Must contain a reference to the PM domain. +Please refer to the binding documentation for the clock and/or PM domain +providers for more details. + + +Example: + + bsc: bus@fec10000 { + compatible = "renesas,bsc-sh73a0", "renesas,bsc", + "simple-pm-bus"; + #address-cells = <1>; + #size-cells = <1>; + ranges = <0 0 0x20000000>; + reg = <0xfec10000 0x400>; + interrupts = <0 39 IRQ_TYPE_LEVEL_HIGH>; + clocks = <&zb_clk>; + power-domains = <&pd_a4s>; + }; diff --git a/drivers/core/Kconfig b/drivers/core/Kconfig index 3b95b5387b..0cd687526e 100644 --- a/drivers/core/Kconfig +++ b/drivers/core/Kconfig @@ -195,6 +195,13 @@ config SPL_SIMPLE_BUS Supports the 'simple-bus' driver, which is used on some systems in SPL.
+config SIMPLE_PM_BUS + bool "Support simple-pm-bus driver" + depends on DM && OF_CONTROL && CLK && POWER_DOMAIN + help + Supports the 'simple-pm-bus' driver, which is used for busses that + have power domains and/or clocks which need to be enabled before use. + config OF_TRANSLATE bool "Translate addresses using fdt_translate_address" depends on DM && OF_CONTROL diff --git a/drivers/core/Makefile b/drivers/core/Makefile index bce7467da1..284af7caaa 100644 --- a/drivers/core/Makefile +++ b/drivers/core/Makefile @@ -6,6 +6,7 @@ obj-y += device.o fdtaddr.o lists.o root.o uclass.o util.o obj-$(CONFIG_DEVRES) += devres.o obj-$(CONFIG_$(SPL_)DM_DEVICE_REMOVE) += device-remove.o obj-$(CONFIG_$(SPL_)SIMPLE_BUS) += simple-bus.o +obj-$(CONFIG_SIMPLE_PM_BUS) += simple-pm-bus.o obj-$(CONFIG_DM) += dump.o obj-$(CONFIG_$(SPL_TPL_)REGMAP) += regmap.o obj-$(CONFIG_$(SPL_TPL_)SYSCON) += syscon-uclass.o diff --git a/drivers/core/simple-pm-bus.c b/drivers/core/simple-pm-bus.c new file mode 100644 index 0000000000..2313bd9a27 --- /dev/null +++ b/drivers/core/simple-pm-bus.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2020 Sean Anderson seanga2@gmail.com + */ + +#include <common.h> +#include <clk.h> +#include <dm.h> + +/* + * Power domains are taken care of by driver_probe, so we just have to enable + * clocks + */ +static const int simple_pm_bus_probe(struct udevice *dev) +{ + int ret; + struct clk_bulk *bulk = dev_get_priv(dev); + + ret = clk_get_bulk(dev, bulk); + if (ret) + return ret; + + ret = clk_enable_bulk(bulk); + if (ret && ret != -ENOSYS && ret != -ENOTSUPP) { + clk_release_bulk(bulk); + return ret; + } + return 0; +} + +static const int simple_pm_bus_remove(struct udevice *dev) +{ + int ret; + struct clk_bulk *bulk = dev_get_priv(dev); + + ret = clk_release_bulk(bulk); + if (ret && ret != -ENOSYS && ret != -ENOTSUPP) + return ret; + else + return 0; +} + +static const struct udevice_id simple_pm_bus_ids[] = { + { .compatible = "simple-pm-bus" }, + { } +}; + +U_BOOT_DRIVER(simple_pm_bus_drv) = { + .name = "simple_pm_bus", + .id = UCLASS_SIMPLE_BUS, + .of_match = simple_pm_bus_ids, + .probe = simple_pm_bus_probe, + .remove = simple_pm_bus_remove, + .priv_auto_alloc_size = sizeof(struct clk_bulk), + .flags = DM_FLAG_PRE_RELOC, +}; diff --git a/test/dm/Makefile b/test/dm/Makefile index ef6065b60f..e0be0d684f 100644 --- a/test/dm/Makefile +++ b/test/dm/Makefile @@ -71,4 +71,5 @@ obj-$(CONFIG_DM_MDIO) += mdio.o obj-$(CONFIG_DM_MDIO_MUX) += mdio_mux.o obj-$(CONFIG_DM_RNG) += rng.o obj-$(CONFIG_CLK_K210_SET_RATE) += k210_pll.o +obj-$(CONFIG_SIMPLE_PM_BUS) += simple-pm-bus.o endif diff --git a/test/dm/simple-pm-bus.c b/test/dm/simple-pm-bus.c new file mode 100644 index 0000000000..978c7f191e --- /dev/null +++ b/test/dm/simple-pm-bus.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020 Sean Anderson seanga2@gmail.com + */ + +#include <common.h> +#include <dm.h> +#include <dm/test.h> +#include <dm/device-internal.h> +#include <test/ut.h> +#include <asm/clk.h> +#include <asm/power-domain.h> + +/* These must match the ids in the device tree */ +#define TEST_CLOCK_ID 4 +#define TEST_POWER_ID 1 + +static int dm_test_simple_pm_bus(struct unit_test_state *uts) +{ + struct udevice *power; + struct udevice *clock; + struct udevice *bus; + + ut_assertok(uclass_get_device_by_name(UCLASS_POWER_DOMAIN, + "power-domain", &power)); + ut_assertok(uclass_get_device_by_name(UCLASS_CLK, "clk-sbox", + &clock)); + ut_asserteq(0, sandbox_power_domain_query(power, TEST_POWER_ID)); + ut_asserteq(0, sandbox_clk_query_enable(clock, TEST_CLOCK_ID)); + + ut_assertok(uclass_get_device_by_name(UCLASS_SIMPLE_BUS, "pm-bus-test", + &bus)); + ut_asserteq(1, sandbox_power_domain_query(power, TEST_POWER_ID)); + ut_asserteq(1, sandbox_clk_query_enable(clock, TEST_CLOCK_ID)); + + ut_assertok(device_remove(bus, DM_REMOVE_NORMAL)); + /* must re-probe since device_remove also removes the power domain */ + ut_assertok(uclass_get_device_by_name(UCLASS_POWER_DOMAIN, + "power-domain", &power)); + ut_asserteq(0, sandbox_power_domain_query(power, TEST_POWER_ID)); + ut_asserteq(0, sandbox_clk_query_enable(clock, TEST_CLOCK_ID)); + + return 0; +} +DM_TEST(dm_test_simple_pm_bus, DM_TESTF_SCAN_FDT);