[PATCH 18/31] misc: am33xx: add control module driver

Lokesh Vutla lokeshvutla at ti.com
Thu Sep 3 08:31:03 CEST 2020



On 25/08/20 2:51 pm, Dario Binacchi wrote:
> 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 at 0' node to bind the
> 'clocks' node and in turn its sub-nodes.
> The 'scm at 210000' node is therefore the node closest to the 'clocks' node
> whose driver can bind all the 'clocks' sub-nodes.
> 
> scm: scm at 210000 {
> 	compatible = "ti,am3-scm", "simple-bus";
> 	...
> 
> 	scm_conf: scm_conf at 0 {
> 		compatible = "syscon", "simple-bus";
> 		#address-cells = <1>;
> 		#size-cells = <1>;
> 		ranges = <0 0 0x800>;
> 
> 		scm_clocks: clocks {
> 			#address-cells = <1>;
> 			#size-cells = <0>;
> 		};
> 	};
> };
> 
> Signed-off-by: Dario Binacchi <dariobin at libero.it>
> ---
> 
>  doc/device-tree-bindings/arm/omap,ctrl.txt    |  82 ++++++
>  .../pinctrl/pinctrl-single.txt                | 255 ++++++++++++++++++

This documentation does not belong to this patch.

>  drivers/misc/Kconfig                          |   7 +
>  drivers/misc/Makefile                         |   1 +
>  drivers/misc/ti-am3-scm.c                     |  90 +++++++
>  5 files changed, 435 insertions(+)
>  create mode 100644 doc/device-tree-bindings/arm/omap,ctrl.txt
>  create mode 100644 doc/device-tree-bindings/pinctrl/pinctrl-single.txt
>  create mode 100644 drivers/misc/ti-am3-scm.c
> 
> diff --git a/doc/device-tree-bindings/arm/omap,ctrl.txt b/doc/device-tree-bindings/arm/omap,ctrl.txt
> new file mode 100644
> index 0000000000..8efd321cfa
> --- /dev/null
> +++ b/doc/device-tree-bindings/arm/omap,ctrl.txt
> @@ -0,0 +1,82 @@
> +OMAP Control Module bindings
> +
> +Control Module contains miscellaneous features under it based on SoC type.
> +Pincontrol is one common feature, and it has a specialized support
> +described in [1]. Typically some clock nodes are also under control module.
> +Syscon is used to share register level access to drivers external to
> +control module driver itself.
> +
> +See [2] for documentation about clock/clockdomain nodes.
> +
> +[1] doc/device-tree-bindings/pinctrl/pinctrl-single.txt
> +[2] doc/device-tree-bindings/clock/ti,*.txt
> +
> +Required properties:
> +- compatible:	Must be one of:
> +		"ti,am3-scm"
> +		"ti,am4-scm"
> +		"ti,dm814-scrm"
> +		"ti,dm816-scrm"
> +		"ti,omap2-scm"
> +		"ti,omap3-scm"
> +		"ti,omap4-scm-core"
> +		"ti,omap4-scm-padconf-core"
> +		"ti,omap4-scm-wkup"
> +		"ti,omap4-scm-padconf-wkup"
> +		"ti,omap5-scm-core"
> +		"ti,omap5-scm-padconf-core"
> +		"ti,omap5-scm-wkup-pad-conf"
> +		"ti,dra7-scm-core"
> +- reg:		Contains Control Module register address range
> +		(base address and length)
> +
> +Optional properties:
> +- clocks:	clocks for this module
> +- clockdomains:	clockdomains for this module
> +
> +Examples:
> +
> +scm: scm at 2000 {
> +	compatible = "ti,omap3-scm", "simple-bus";
> +	reg = <0x2000 0x2000>;
> +	#address-cells = <1>;
> +	#size-cells = <1>;
> +	ranges = <0 0x2000 0x2000>;
> +
> +	omap3_pmx_core: pinmux at 30 {
> +		compatible = "ti,omap3-padconf",
> +			     "pinctrl-single";
> +		reg = <0x30 0x230>;
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		#interrupt-cells = <1>;
> +		interrupt-controller;
> +		pinctrl-single,register-width = <16>;
> +		pinctrl-single,function-mask = <0xff1f>;
> +	};
> +
> +	scm_conf: scm_conf at 270 {
> +		compatible = "syscon";
> +		reg = <0x270 0x330>;
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +
> +		scm_clocks: clocks {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +		};
> +	};
> +
> +	scm_clockdomains: clockdomains {
> +	};
> +}
> +
> +&scm_clocks {
> +	mcbsp5_mux_fck: mcbsp5_mux_fck {
> +		#clock-cells = <0>;
> +		compatible = "ti,composite-mux-clock";
> +		clocks = <&core_96m_fck>, <&mcbsp_clks>;
> +		ti,bit-shift = <4>;
> +		reg = <0x02d8>;
> +	};
> +};

[...snip...]


> 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..e5f4f09261
> --- /dev/null
> +++ b/drivers/misc/ti-am3-scm.c
> @@ -0,0 +1,90 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * AM335x specific control module (scm)
> + *
> + * Copyright (C) 2020 Dario Binacchi <dariobin at libero.it>
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <dm/lists.h>
> +#include <linux/err.h>
> +
> +static int ti_am3_scm_bind(struct udevice *dev)
> +{
> +	int err;
> +	struct udevice *conf_dev;
> +	ofnode clocks_node, conf_node;
> +
> +	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 at 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;
> +	}

Isn't clock node an optional property?

Also do we really need a separate UBOOT_DRIVER for scm_clocks? Can it be handled
in the same driver?

Thanks and regards,
Lokesh

> +
> +	err = device_bind_driver_to_node(conf_dev, "ti_am3_scm_clocks",
> +					 "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,
> +};
> +
> +static int ti_am3_scm_clocks_bind(struct udevice *dev)
> +{
> +	ofnode node;
> +	int err;
> +
> +	dev_dbg(dev, "%s: dev=%p\n", __func__, dev);
> +	ofnode_for_each_subnode(node, dev_ofnode(dev)) {
> +		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;
> +}
> +
> +U_BOOT_DRIVER(ti_am3_scm_clocks) = {
> +	.name = "ti_am3_scm_clocks",
> +	.id = UCLASS_SIMPLE_BUS,
> +	.bind = ti_am3_scm_clocks_bind,
> +};
> 


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