The implementation of this driver was needed to bind the sub-nodes of the 'clocks' node. In fact, the lack of the compatible property in the 'clocks' node does not allow the generic 'simple-bus' driver to bind the 'clocks' node and in turn its sub-nodes. The 'prcm@200000' 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.
prcm: prcm@200000 { compatible = "ti,am3-prcm", "simple-bus"; reg = <0x200000 0x4000>; #address-cells = <1>; #size-cells = <1>; ranges = <0 0x200000 0x4000>;
prcm_clocks: clocks { #address-cells = <1>; #size-cells = <0>; };
prcm_clockdomains: clockdomains { }; };
&prcm_clocks { ... dpll_core_ck: dpll_core_ck@490 { #clock-cells = <0>; compatible = "ti,am3-dpll-core-clock"; clocks = <&sys_clkin_ck>, <&sys_clkin_ck>; reg = <0x0490>, <0x045c>, <0x0468>; }; ... };
For DT binding details see Linux doc: - Documentation/devicetree/bindings/arm/omap/prcm.txt
Signed-off-by: Dario Binacchi dariobin@libero.it
---
(no changes since v4)
Changes in v4: - Include device_compat.h header for dev_xxx macros.
Changes in v3: - Add to commit message the references to linux kernel dt binding documentation.
Changes in v2: - Remove the 'ti_am3_prcm_clocks' driver. Handle 'prcm_clocks' node in the 'ti_am3_prcm' driver. - Update the commit message.
drivers/clk/ti/Makefile | 7 ++++- drivers/clk/ti/am3-prcm.c | 66 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 72 insertions(+), 1 deletion(-) create mode 100644 drivers/clk/ti/am3-prcm.c
diff --git a/drivers/clk/ti/Makefile b/drivers/clk/ti/Makefile index dbd343069c..c929fe4e28 100644 --- a/drivers/clk/ti/Makefile +++ b/drivers/clk/ti/Makefile @@ -3,7 +3,12 @@ # Copyright (C) 2020 Dario Binacchi dariobin@libero.it #
-obj-$(CONFIG_ARCH_OMAP2PLUS) += clk.o omap4-cm.o +ifeq ($(CONFIG_ARCH_OMAP2PLUS), y) + +obj-y += clk.o omap4-cm.o +obj-$(CONFIG_AM33XX) += am3-prcm.o + +endif # CONFIG_ARCH_OMAP2PLUS
obj-$(CONFIG_CLK_TI_AM3_DPLL) += clk-am3-dpll.o clk-am3-dpll-x2.o obj-$(CONFIG_CLK_TI_CTRL) += clk-ctrl.o diff --git a/drivers/clk/ti/am3-prcm.c b/drivers/clk/ti/am3-prcm.c new file mode 100644 index 0000000000..af2a5a2fe6 --- /dev/null +++ b/drivers/clk/ti/am3-prcm.c @@ -0,0 +1,66 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * AM335x power reset and clock manager (prcm) + * + * 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_prcm_bind(struct udevice *dev) +{ + ofnode clocks_node, node; + 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; + } + + clocks_node = ofnode_find_subnode(dev_ofnode(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(dev, "ti_am3_prcm", "prcm_clocks", + clocks_node, NULL); + if (err) { + dev_err(dev, "%s: failed to bind prcm_clocks\n", __func__); + return err; + } + + return 0; +} + +static const struct udevice_id ti_am3_prcm_ids[] = { + {.compatible = "ti,am3-prcm"}, + {} +}; + +U_BOOT_DRIVER(ti_am3_prcm) = { + .name = "ti_am3_prcm", + .id = UCLASS_SIMPLE_BUS, + .of_match = ti_am3_prcm_ids, + .bind = ti_am3_prcm_bind, +};