[PATCH v6 03/28] bus: ti: add minimal sysc interconnect target driver

[Lokesh Vutla]

On 22/11/20 9:41 pm, Dario Binacchi wrote:
> We can handle the sysc interconnect target module in a generic way for
> many TI SoCs. Initially let's just enable domain clocks before the
> children are probed.
> 
> The code is loosely based on the drivers/bus/ti-sysc.c of the Linux
> kernel version 5.9-rc7.
> For DT binding details see:
> - Documentation/devicetree/bindings/bus/ti-sysc.txt
> 
> Signed-off-by: Dario Binacchi <dariobin at libero.it>
> 
> ---
> 
> (no changes since v4)
> 
> Changes in v4:
> - Include device_compat.h header for dev_xxx macros.
> 
>  arch/arm/Kconfig      |   1 +
>  drivers/bus/Kconfig   |   7 ++
>  drivers/bus/Makefile  |   1 +
>  drivers/bus/ti-sysc.c | 166 ++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 175 insertions(+)
>  create mode 100644 drivers/bus/ti-sysc.c
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 5903c09370..4cc2c242d1 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -799,6 +799,7 @@ config ARCH_OMAP2PLUS
>  	select SPL_BOARD_INIT if SPL
>  	select SPL_STACK_R if SPL
>  	select SUPPORT_SPL
> +	select TI_SYSC

Not all OMAP2 platform need TI_SYSC. With this change nokia builds are failing.
I will make this as imply and disable it in Nokia config.

Thanks and regards,
Lokesh

>  	imply FIT
>  
>  config ARCH_MESON
> diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
> index 07a33c6287..733bec5a56 100644
> --- a/drivers/bus/Kconfig
> +++ b/drivers/bus/Kconfig
> @@ -5,6 +5,13 @@
>  
>  menu "Bus devices"
>  
> +config TI_SYSC
> +	bool "TI sysc interconnect target module driver"
> +	depends on ARCH_OMAP2PLUS
> +	help
> +	  Generic driver for Texas Instruments interconnect target module
> +	  found on many TI SoCs.
> +
>  config UNIPHIER_SYSTEM_BUS
>  	bool "UniPhier System Bus driver"
>  	depends on ARCH_UNIPHIER
> diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
> index 0b97fc1f8b..875bb4ed42 100644
> --- a/drivers/bus/Makefile
> +++ b/drivers/bus/Makefile
> @@ -3,4 +3,5 @@
>  # Makefile for the bus drivers.
>  #
>  
> +obj-$(CONFIG_TI_SYSC)	+= ti-sysc.o
>  obj-$(CONFIG_UNIPHIER_SYSTEM_BUS) += uniphier-system-bus.o
> diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c
> new file mode 100644
> index 0000000000..65974a70a6
> --- /dev/null
> +++ b/drivers/bus/ti-sysc.c
> @@ -0,0 +1,166 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Texas Instruments sysc interconnect target driver
> + *
> + * Copyright (C) 2020 Dario Binacchi <dariobin at libero.it>
> + */
> +
> +#include <common.h>
> +#include <clk.h>
> +#include <dm.h>
> +#include <dm/device_compat.h>
> +
> +enum ti_sysc_clocks {
> +	TI_SYSC_FCK,
> +	TI_SYSC_ICK,
> +	TI_SYSC_MAX_CLOCKS,
> +};
> +
> +static const char *const clock_names[] = {"fck", "ick"};
> +
> +struct ti_sysc_priv {
> +	int clocks_count;
> +	struct clk clocks[TI_SYSC_MAX_CLOCKS];
> +};
> +
> +static const struct udevice_id ti_sysc_ids[] = {
> +	{.compatible = "ti,sysc-omap2"},
> +	{.compatible = "ti,sysc-omap4"},
> +	{.compatible = "ti,sysc-omap4-simple"},
> +	{.compatible = "ti,sysc-omap3430-sr"},
> +	{.compatible = "ti,sysc-omap3630-sr"},
> +	{.compatible = "ti,sysc-omap4-sr"},
> +	{.compatible = "ti,sysc-omap3-sham"},
> +	{.compatible = "ti,sysc-omap-aes"},
> +	{.compatible = "ti,sysc-mcasp"},
> +	{.compatible = "ti,sysc-usb-host-fs"},
> +	{}
> +};
> +
> +static int ti_sysc_get_one_clock(struct udevice *dev, enum ti_sysc_clocks index)
> +{
> +	struct ti_sysc_priv *priv = dev_get_priv(dev);
> +	const char *name;
> +	int err;
> +
> +	switch (index) {
> +	case TI_SYSC_FCK:
> +		break;
> +	case TI_SYSC_ICK:
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	name = clock_names[index];
> +
> +	err = clk_get_by_name(dev, name, &priv->clocks[index]);
> +	if (err) {
> +		if (err == -ENODATA)
> +			return 0;
> +
> +		dev_err(dev, "failed to get %s clock\n", name);
> +		return err;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ti_sysc_put_clocks(struct udevice *dev)
> +{
> +	struct ti_sysc_priv *priv = dev_get_priv(dev);
> +	int err;
> +
> +	err = clk_release_all(priv->clocks, priv->clocks_count);
> +	if (err)
> +		dev_err(dev, "failed to release all clocks\n");
> +
> +	return err;
> +}
> +
> +static int ti_sysc_get_clocks(struct udevice *dev)
> +{
> +	struct ti_sysc_priv *priv = dev_get_priv(dev);
> +	int i, err;
> +
> +	for (i = 0; i < TI_SYSC_MAX_CLOCKS; i++) {
> +		err = ti_sysc_get_one_clock(dev, i);
> +		if (!err)
> +			priv->clocks_count++;
> +		else if (err != -ENOENT)
> +			return err;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ti_sysc_child_post_remove(struct udevice *dev)
> +{
> +	struct ti_sysc_priv *priv = dev_get_priv(dev->parent);
> +	int i, err;
> +
> +	for (i = 0; i < priv->clocks_count; i++) {
> +		err = clk_disable(&priv->clocks[i]);
> +		if (err) {
> +			dev_err(dev->parent, "failed to disable %s clock\n",
> +				clock_names[i]);
> +			return err;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int ti_sysc_child_pre_probe(struct udevice *dev)
> +{
> +	struct ti_sysc_priv *priv = dev_get_priv(dev->parent);
> +	int i, err;
> +
> +	for (i = 0; i < priv->clocks_count; i++) {
> +		err = clk_enable(&priv->clocks[i]);
> +		if (err) {
> +			dev_err(dev->parent, "failed to enable %s clock\n",
> +				clock_names[i]);
> +			return err;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int ti_sysc_remove(struct udevice *dev)
> +{
> +	return ti_sysc_put_clocks(dev);
> +}
> +
> +static int ti_sysc_probe(struct udevice *dev)
> +{
> +	int err;
> +
> +	err = ti_sysc_get_clocks(dev);
> +	if (err)
> +		goto clocks_err;
> +
> +	return 0;
> +
> +clocks_err:
> +	ti_sysc_put_clocks(dev);
> +	return err;
> +}
> +
> +UCLASS_DRIVER(ti_sysc) = {
> +	.id = UCLASS_SIMPLE_BUS,
> +	.name = "ti_sysc",
> +	.post_bind = dm_scan_fdt_dev
> +};
> +
> +U_BOOT_DRIVER(ti_sysc) = {
> +	.name = "ti_sysc",
> +	.id = UCLASS_SIMPLE_BUS,
> +	.of_match = ti_sysc_ids,
> +	.probe = ti_sysc_probe,
> +	.remove = ti_sysc_remove,
> +	.child_pre_probe = ti_sysc_child_pre_probe,
> +	.child_post_remove = ti_sysc_child_post_remove,
> +	.priv_auto_alloc_size = sizeof(struct ti_sysc_priv)
> +};
>