Re: [PATCH v2 06/11] mfd: olb: Add support for Mobileye OLB system-controller

[Lee Jones]

On Fri, 03 May 2024, Théo Lebrun wrote:

> Mobileye OLB system-controller gets used in EyeQ5, EyeQ6L and EyeQ6H
> platforms. It hosts clock, reset and pinctrl functionality.
> 
> Tiny iomem resources are declared for all cells. Some features are
> spread apart. Pinctrl is only used on EyeQ5.
> 
> EyeQ6H is special: it hosts seven OLB controllers, each with a
> compatible. That means many clock and reset cells. Use cell->devname
> for explicit device names rather than clk-eyeq.ID or clk-eyeq.ID.auto.
> 
> Signed-off-by: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>
> ---
>  drivers/mfd/Kconfig        |  10 +++
>  drivers/mfd/Makefile       |   2 +
>  drivers/mfd/mobileye-olb.c | 180 +++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 192 insertions(+)
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 4b023ee229cf..d004a3f4d493 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -1030,6 +1030,16 @@ config MFD_OCELOT
>  
>  	  If unsure, say N.
>  
> +config MFD_OLB
> +	bool "Mobileye EyeQ OLB System Controller Support"
> +	select MFD_CORE
> +	depends on MACH_EYEQ5 || MACH_EYEQ6H || COMPILE_TEST
> +	default MACH_EYEQ5 || MACH_EYEQ6H
> +	help
> +	  Say yes here to add support for EyeQ platforms (EyeQ5, EyeQ6L and
> +	  EyeQ6H). This core MFD platform driver provides clock, reset and
> +	  pinctrl (only EyeQ5) support.
> +
>  config EZX_PCAP
>  	bool "Motorola EZXPCAP Support"
>  	depends on SPI_MASTER
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index c66f07edcd0e..d872833966a8 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -120,6 +120,8 @@ obj-$(CONFIG_MFD_CORE)		+= mfd-core.o
>  ocelot-soc-objs			:= ocelot-core.o ocelot-spi.o
>  obj-$(CONFIG_MFD_OCELOT)	+= ocelot-soc.o
>  
> +obj-$(CONFIG_MFD_OLB)		+= mobileye-olb.o
> +
>  obj-$(CONFIG_EZX_PCAP)		+= ezx-pcap.o
>  obj-$(CONFIG_MFD_CPCAP)		+= motorola-cpcap.o
>  
> diff --git a/drivers/mfd/mobileye-olb.c b/drivers/mfd/mobileye-olb.c
> new file mode 100644
> index 000000000000..1640d63a3ddd
> --- /dev/null
> +++ b/drivers/mfd/mobileye-olb.c
> @@ -0,0 +1,180 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * System controller multi-function device for EyeQ platforms.
> + *
> + * Mobileye EyeQ5, EyeQ6L and EyeQ6H platforms have MMIO mapped registers
> + * controlling core platform clocks, resets and pin control. Many other
> + * features are present and not yet exposed.
> + *
> + * Declare cells for each compatible. Only EyeQ5 has pinctrl.
> + * EyeQ6H has seven OLB instances; each has a name which we propagate to
> + * sub-devices using cell->devname.
> + *
> + * Copyright (C) 2024 Mobileye Vision Technologies Ltd.
> + */
> +
> +#include <linux/array_size.h>
> +#include <linux/device.h>
> +#include <linux/errno.h>
> +#include <linux/ioport.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/platform_device.h>
> +#include <linux/property.h>
> +
> +#define OLB_MFD_CELL(_name, _res, _devname) \
> +	MFD_CELL_ALL(_name, _res, NULL, 0, 0, NULL, 0, false, NULL, _devname)

The reason we provide generic MACROs is so that you don't have to define
your own.

> +struct olb_match_data {
> +	const struct mfd_cell	*cells;
> +	int			nb_cells; /* int to match devm_mfd_add_devices() argument */
> +};
> +
> +#define OLB_DATA(_cells) { .cells = (_cells), .nb_cells = ARRAY_SIZE(_cells) }
> +
> +static int olb_probe(struct platform_device *pdev)
> +{
> +	const struct olb_match_data *match_data;
> +	struct device *dev = &pdev->dev;
> +	struct resource *res;
> +
> +	match_data = device_get_match_data(dev);
> +	if (!match_data)
> +		return -ENODEV;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res)
> +		return -ENODEV;
> +
> +	return devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
> +				    match_data->cells, match_data->nb_cells,
> +				    res, 0, NULL);
> +}
> +
> +static const struct resource olb_eyeq5_clk_resources[] = {
> +	DEFINE_RES_MEM_NAMED(0x02C, 10 * 8, "pll"),
> +	DEFINE_RES_MEM_NAMED(0x11C, 1 * 4, "ospi"),
> +};
> +
> +static const struct resource olb_eyeq5_reset_resources[] = {
> +	DEFINE_RES_MEM_NAMED(0x004, 2 * 4, "d0"),
> +	DEFINE_RES_MEM_NAMED(0x200, 13 * 4, "d1"),
> +	DEFINE_RES_MEM_NAMED(0x120, 1 * 4, "d2"),
> +};
> +
> +static const struct resource olb_eyeq5_pinctrl_resources[] = {
> +	DEFINE_RES_MEM_NAMED(0x0B0, 12 * 4, "pinctrl"),
> +};
> +
> +static const struct mfd_cell olb_eyeq5_cells[] = {
> +	OLB_MFD_CELL("clk-eyeq", olb_eyeq5_clk_resources, NULL),
> +	OLB_MFD_CELL("reset-eyeq", olb_eyeq5_reset_resources, NULL),
> +	OLB_MFD_CELL("eyeq5-pinctrl", olb_eyeq5_pinctrl_resources, NULL),
> +};
> +
> +static const struct olb_match_data olb_eyeq5_match_data = OLB_DATA(olb_eyeq5_cells);
> +
> +static const struct resource olb_eyeq6l_clk_resources[] = {
> +	DEFINE_RES_MEM_NAMED(0x02C, 4 * 8, "pll"),
> +};
> +
> +static const struct resource olb_eyeq6l_reset_resources[] = {
> +	DEFINE_RES_MEM_NAMED(0x004, 2 * 4, "d0"),
> +	DEFINE_RES_MEM_NAMED(0x200, 13 * 4, "d1"),
> +};
> +
> +static const struct mfd_cell olb_eyeq6l_cells[] = {
> +	OLB_MFD_CELL("clk-eyeq", olb_eyeq6l_clk_resources, NULL),
> +	OLB_MFD_CELL("reset-eyeq", olb_eyeq6l_reset_resources, NULL),
> +};
> +
> +static const struct olb_match_data olb_eyeq6l_match_data = OLB_DATA(olb_eyeq6l_cells);
> +
> +static const struct resource olb_eyeq6h_acc_clk_resources[] = {
> +	DEFINE_RES_MEM_NAMED(0x040, 7 * 8, "pll"),
> +};
> +
> +static const struct resource olb_eyeq6h_acc_reset_resources[] = {
> +	DEFINE_RES_MEM_NAMED(0x000, 15 * 4, "d0"),
> +};
> +
> +static const struct mfd_cell olb_eyeq6h_acc_cells[] = {
> +	OLB_MFD_CELL("clk-eyeq", olb_eyeq6h_acc_clk_resources, "clk-eyeq-acc"),

The point of enumerating platform device names is to identify devices
that are identical.  We lose this with bespoke naming.

If you want to identify devices either define a value to pass to .id or
adapt the first parameter and make the clk-eyeq driver accept different
device names.

> +	OLB_MFD_CELL("reset-eyeq", olb_eyeq6h_acc_reset_resources, "reset-eyeq-acc"),
> +};
> +
> +static const struct olb_match_data olb_eyeq6h_acc_match_data = OLB_DATA(olb_eyeq6h_acc_cells);
> +
> +static const struct resource olb_eyeq6h_we_clk_resources[] = {
> +	DEFINE_RES_MEM_NAMED(0x074, 1 * 8, "pll"),
> +};
> +
> +static const struct resource olb_eyeq6h_we_reset_resources[] = {
> +	DEFINE_RES_MEM_NAMED(0x004, 4 * 4, "d0"),
> +};
> +
> +static const struct mfd_cell olb_eyeq6h_west_cells[] = {
> +	OLB_MFD_CELL("clk-eyeq", olb_eyeq6h_we_clk_resources, "clk-eyeq-west"),
> +	OLB_MFD_CELL("reset-eyeq", olb_eyeq6h_we_reset_resources, "reset-eyeq-west"),
> +};
> +
> +static const struct olb_match_data olb_eyeq6h_west_match_data = OLB_DATA(olb_eyeq6h_west_cells);
> +
> +static const struct mfd_cell olb_eyeq6h_east_cells[] = {
> +	OLB_MFD_CELL("clk-eyeq", olb_eyeq6h_we_clk_resources, "clk-eyeq-east"),
> +	OLB_MFD_CELL("reset-eyeq", olb_eyeq6h_we_reset_resources, "reset-eyeq-east"),
> +};
> +
> +static const struct olb_match_data olb_eyeq6h_east_match_data = OLB_DATA(olb_eyeq6h_east_cells);
> +
> +static const struct resource olb_eyeq6h_south_clk_resources[] = {
> +	DEFINE_RES_MEM_NAMED(0x000, 4 * 8, "pll"),
> +	DEFINE_RES_MEM_NAMED(0x070, 1 * 4, "emmc"),
> +	DEFINE_RES_MEM_NAMED(0x090, 1 * 4, "ospi"),
> +	DEFINE_RES_MEM_NAMED(0x098, 1 * 4, "tsu"),
> +};
> +
> +static const struct mfd_cell olb_eyeq6h_south_cells[] = {
> +	OLB_MFD_CELL("clk-eyeq", olb_eyeq6h_south_clk_resources, "clk-eyeq-south"),
> +};
> +
> +static const struct olb_match_data olb_eyeq6h_south_match_data = OLB_DATA(olb_eyeq6h_south_cells);
> +
> +static const struct resource olb_eyeq6h_ddr_clk_resources[] = {
> +	DEFINE_RES_MEM_NAMED(0x074, 1 * 8, "pll"),
> +};
> +
> +static const struct mfd_cell olb_eyeq6h_ddr0_cells[] = {
> +	OLB_MFD_CELL("clk-eyeq", olb_eyeq6h_ddr_clk_resources, "clk-eyeq-ddr0"),
> +};
> +
> +static const struct olb_match_data olb_eyeq6h_ddr0_match_data = OLB_DATA(olb_eyeq6h_ddr0_cells);
> +
> +static const struct mfd_cell olb_eyeq6h_ddr1_cells[] = {
> +	OLB_MFD_CELL("clk-eyeq", olb_eyeq6h_ddr_clk_resources, "clk-eyeq-ddr1"),
> +};
> +
> +static const struct olb_match_data olb_eyeq6h_ddr1_match_data = OLB_DATA(olb_eyeq6h_ddr1_cells);
> +
> +static const struct of_device_id olb_of_match[] = {
> +	{ .compatible = "mobileye,eyeq5-olb", .data = &olb_eyeq5_match_data },

We're not passing MFD init data through the OF API, sorry.

Pass defined identifiers through instead and match on those please.

> +	{ .compatible = "mobileye,eyeq6l-olb", .data = &olb_eyeq6l_match_data },
> +	{ .compatible = "mobileye,eyeq6h-acc-olb", .data = &olb_eyeq6h_acc_match_data },
> +	/* No central: it only has an early clock handled using CLK_OF_DECLARE_DRIVER(). */
> +	{ .compatible = "mobileye,eyeq6h-east-olb", .data = &olb_eyeq6h_east_match_data },
> +	{ .compatible = "mobileye,eyeq6h-west-olb", .data = &olb_eyeq6h_west_match_data },
> +	{ .compatible = "mobileye,eyeq6h-south-olb", .data = &olb_eyeq6h_south_match_data },
> +	{ .compatible = "mobileye,eyeq6h-ddr0-olb", .data = &olb_eyeq6h_ddr0_match_data },
> +	{ .compatible = "mobileye,eyeq6h-ddr1-olb", .data = &olb_eyeq6h_ddr1_match_data },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, olb_of_match);
> +
> +static struct platform_driver olb_driver = {
> +	.probe =  olb_probe,
> +	.driver = {
> +		.name = "olb",
> +		.of_match_table = olb_of_match,
> +	},
> +};
> +builtin_platform_driver(olb_driver);
> 
> -- 
> 2.45.0
> 

-- 
Lee Jones [李琼斯]