The implementation of this driver was needed to bind the device tree sub-nodes of the 'clocks' node. In fact, the lack of the compatible property in the 'clocks' node does not allow the generic 'syscon' or 'simple-bus' drivers linked to the 'scm_conf@0' node to bind the 'clocks' node and in turn its sub-nodes. The 'scm@210000' node is therefore the node closest to the 'clocks' node whose driver can bind all the 'clocks' sub-nodes. In this way, the address translation functions are able to walk along the device tree towards the upper nodes until the address composition is completed.
scm: scm@210000 { compatible = "ti,am3-scm", "simple-bus"; ...
scm_conf: scm_conf@0 { compatible = "syscon", "simple-bus"; #address-cells = <1>; #size-cells = <1>; ranges = <0 0 0x800>;
scm_clocks: clocks { #address-cells = <1>; #size-cells = <0>; }; }; };
For DT binding details see Linux doc: - Documentation/devicetree/bindings/arm/omap/ctrl.txt
Signed-off-by: Dario Binacchi dariobin@libero.it
---
Changes in v4: - Include device_compat.h header for dev_xxx macros.
Changes in v3: - Remove doc/device-tree-bindings/arm/omap,ctrl.txt. - Remove doc/device-tree-bindings/pinctrl/pinctrl-single.txt. - Add to commit message the references to linux kernel dt binding documentation.
Changes in v2: - Remove the 'ti_am3_scm_clocks' driver. Handle 'scm_clocks' node in the 'ti_am3_scm' driver. - Update the commit message.
drivers/misc/Kconfig | 7 ++++ drivers/misc/Makefile | 1 + drivers/misc/ti-am3-scm.c | 82 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 90 insertions(+) create mode 100644 drivers/misc/ti-am3-scm.c
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index b67e906a76..9e8b676637 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -500,4 +500,11 @@ config ESM_PMIC Support ESM (Error Signal Monitor) on PMIC devices. ESM is used typically to reboot the board in error condition.
+config TI_AM3_SCM + bool "AM33XX specific control module support (SCM)" + depends on ARCH_OMAP2PLUS + help + The control module includes status and control logic not addressed + within the peripherals or the rest of the device infrastructure. + endmenu diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index 947bd3a647..056fb3b522 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -75,3 +75,4 @@ obj-$(CONFIG_MICROCHIP_FLEXCOM) += microchip_flexcom.o obj-$(CONFIG_K3_AVS0) += k3_avs.o obj-$(CONFIG_ESM_K3) += k3_esm.o obj-$(CONFIG_ESM_PMIC) += esm_pmic.o +obj-$(CONFIG_TI_AM3_SCM) += ti-am3-scm.o diff --git a/drivers/misc/ti-am3-scm.c b/drivers/misc/ti-am3-scm.c new file mode 100644 index 0000000000..ed886e6916 --- /dev/null +++ b/drivers/misc/ti-am3-scm.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * AM335x specific control module (scm) + * + * Copyright (C) 2020 Dario Binacchi dariobin@libero.it + */ + +#include <common.h> +#include <dm.h> +#include <dm/device_compat.h> +#include <dm/lists.h> +#include <linux/err.h> + +static int ti_am3_scm_bind(struct udevice *dev) +{ + ofnode clocks_node, conf_node, node; + struct udevice *conf_dev; + int err; + + if (!strcmp("clocks", ofnode_get_name(dev_ofnode(dev)))) { + ofnode_for_each_subnode(node, dev_ofnode(dev)) { + dev_dbg(dev, "%s: node=%s\n", __func__, + ofnode_get_name(node)); + err = lists_bind_fdt(dev, node, NULL, false); + if (err) { + dev_err(dev, "%s: lists_bind_fdt, err=%d\n", + __func__, err); + return err; + } + } + + return 0; + } + + err = dm_scan_fdt_dev(dev); + if (err) { + dev_err(dev, "%s: dm_scan_fdt, err=%d\n", __func__, err); + return err; + } + + conf_node = dev_read_subnode(dev, "scm_conf@0"); + if (!ofnode_valid(conf_node)) { + dev_err(dev, "%s: failed to get conf sub-node\n", __func__); + return -ENODEV; + } + + if (uclass_get_device_by_ofnode(UCLASS_SYSCON, conf_node, &conf_dev)) { + if (uclass_get_device_by_ofnode(UCLASS_SIMPLE_BUS, conf_node, + &conf_dev)) { + dev_err(dev, "%s: failed to get conf device\n", + __func__); + return -ENODEV; + } + } + + clocks_node = dev_read_subnode(conf_dev, "clocks"); + if (!ofnode_valid(clocks_node)) { + dev_err(dev, "%s: failed to get clocks sub-node\n", __func__); + return -ENODEV; + } + + err = device_bind_driver_to_node(conf_dev, "ti_am3_scm", "scm_clocks", + clocks_node, NULL); + if (err) { + dev_err(dev, "%s: failed to bind scm_clocks\n", __func__); + return err; + } + + return 0; +} + +static const struct udevice_id ti_am3_scm_ids[] = { + {.compatible = "ti,am3-scm"}, + {} +}; + +U_BOOT_DRIVER(ti_am3_scm) = { + .name = "ti_am3_scm", + .id = UCLASS_SIMPLE_BUS, + .of_match = ti_am3_scm_ids, + .bind = ti_am3_scm_bind, +};