Re: [PATCH v2] platform/x86: add meraki-mx100 platform driver

[Hans de Goede <hdegoede@xxxxxxxxxx>]

Hi Chris,

On 8/6/21 2:57 AM, Chris Blake wrote:
> This adds platform support for the Cisco Meraki MX100 (Tinkerbell)
> network appliance. This sets up the network LEDs and Reset
> button. Note that this patch requires
> mfd: lpc_ich: Enable GPIO driver for DH89xxCC which has been accepted
> and is currently targeted for 5.15.
> 
> Signed-off-by: Chris Blake <chrisrblake93@xxxxxxxxx>
> Co-developed-by: Christian Lamparter <chunkeey@xxxxxxxxx>
> ---
> 
> Changelog:
> V2: Move to using gpiod lookup tables, misc cleanups

Thank you, I've 2 small remarks and Andy has a couple of remarks
as well. If you can do a v3 with our remarks addressed then I believe
that that v3 will be ready for merging.

> V1: Initial Patch
> 
>  drivers/platform/x86/Kconfig        |  13 ++
>  drivers/platform/x86/Makefile       |   3 +
>  drivers/platform/x86/meraki-mx100.c | 212 ++++++++++++++++++++++++++++
>  3 files changed, 228 insertions(+)
>  create mode 100644 drivers/platform/x86/meraki-mx100.c
> 
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 7d385c3b2239..8d70176e335f 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -302,6 +302,19 @@ config ASUS_NB_WMI
>  	  If you have an ACPI-WMI compatible Asus Notebook, say Y or M
>  	  here.
>  
> +config MERAKI_MX100
> +	tristate "Cisco Meraki MX100 Platform Driver"
> +	depends on GPIOLIB
> +	depends on GPIO_ICH
> +	depends on LEDS_CLASS
> +	select LEDS_GPIO
> +	help
> +	  This driver provides support for the front button and LEDs on
> +	  the Cisco Meraki MX100 (Tinkerbell) 1U appliance.
> +
> +	  To compile this driver as a module, choose M here: the module
> +	  will be called meraki-mx100.
> +
>  config EEEPC_LAPTOP
>  	tristate "Eee PC Hotkey Driver"
>  	depends on ACPI
> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> index 7ee369aab10d..25c5aee1cde7 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -39,6 +39,9 @@ obj-$(CONFIG_ASUS_NB_WMI)	+= asus-nb-wmi.o
>  obj-$(CONFIG_EEEPC_LAPTOP)	+= eeepc-laptop.o
>  obj-$(CONFIG_EEEPC_WMI)		+= eeepc-wmi.o
>  
> +# Cisco/Meraki
> +obj-$(CONFIG_MERAKI_MX100)	+= meraki-mx100.o
> +
>  # Dell
>  obj-$(CONFIG_X86_PLATFORM_DRIVERS_DELL)		+= dell/
>  
> diff --git a/drivers/platform/x86/meraki-mx100.c b/drivers/platform/x86/meraki-mx100.c
> new file mode 100644
> index 000000000000..d64508aeb92c
> --- /dev/null
> +++ b/drivers/platform/x86/meraki-mx100.c
> @@ -0,0 +1,212 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
> +/*
> + * Cisco Meraki MX100 (Tinkerbell) board platform driver
> + *
> + * Based off of arch/x86/platform/meraki/tink.c from the
> + * Meraki GPL release meraki-firmware-sources-r23-20150601
> + *
> + * Format inspired by platform/x86/pcengines-apuv2.c
> + *
> + * Copyright (C) 2021 Chris Blake <chrisrblake93@xxxxxxxxx>
> + */
> +
> +#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
> +
> +#include <linux/dmi.h>
> +#include <linux/err.h>
> +#include <linux/gpio.h>
> +#include <linux/gpio_keys.h>
> +#include <linux/gpio/machine.h>
> +#include <linux/input.h>
> +#include <linux/kernel.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +
> +#define TINK_GPIO_DRIVER_NAME "gpio_ich"
> +
> +/* LEDs */
> +static const struct gpio_led tink_leds[] = {
> +	{
> +		.name = "mx100:green:internet",
> +		.default_trigger = "default-on",
> +	},
> +	{
> +		.name = "mx100:green:lan2",
> +	},
> +	{
> +		.name = "mx100:green:lan3",
> +	},
> +	{
> +		.name = "mx100:green:lan4",
> +	},
> +	{
> +		.name = "mx100:green:lan5",
> +	},
> +	{
> +		.name = "mx100:green:lan6",
> +	},
> +	{
> +		.name = "mx100:green:lan7",
> +	},
> +	{
> +		.name = "mx100:green:lan8",
> +	},
> +	{
> +		.name = "mx100:green:lan9",
> +	},
> +	{
> +		.name = "mx100:green:lan10",
> +	},
> +	{
> +		.name = "mx100:green:lan11",
> +	},
> +};
> +
> +static const struct gpio_led_platform_data tink_leds_pdata = {
> +	.num_leds	= ARRAY_SIZE(tink_leds),
> +	.leds		= tink_leds,
> +};
> +
> +static struct gpiod_lookup_table tink_leds_table = {
> +	.dev_id = "leds-gpio",
> +	.table = {
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 11,
> +				NULL, 0, GPIO_ACTIVE_LOW),
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 18,
> +				NULL, 1, GPIO_ACTIVE_HIGH),
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 20,
> +				NULL, 2, GPIO_ACTIVE_HIGH),
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 22,
> +				NULL, 3, GPIO_ACTIVE_HIGH),
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 23,
> +				NULL, 4, GPIO_ACTIVE_HIGH),
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 32,
> +				NULL, 5, GPIO_ACTIVE_HIGH),
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 34,
> +				NULL, 6, GPIO_ACTIVE_HIGH),
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 35,
> +				NULL, 7, GPIO_ACTIVE_HIGH),
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 36,
> +				NULL, 8, GPIO_ACTIVE_HIGH),
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 37,
> +				NULL, 9, GPIO_ACTIVE_HIGH),
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 48,
> +				NULL, 10, GPIO_ACTIVE_HIGH),
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 16,
> +				NULL, 11, GPIO_ACTIVE_LOW),
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 7,
> +				NULL, 12, GPIO_ACTIVE_LOW),
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 21,
> +				NULL, 13, GPIO_ACTIVE_LOW),
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 19,
> +				NULL, 14, GPIO_ACTIVE_LOW),

gpiod_lookup_table.table-s needed to be terminated with an
empty entry, add a line like this, like how it is done for
the dmi_system_id table:

		{} /* Terminating entry */


> +	}
> +};
> +
> +/* Reset Button */
> +static struct gpio_keys_button tink_buttons[] = {
> +	{
> +		.desc			= "Reset",
> +		.type			= EV_KEY,
> +		.code			= KEY_RESTART,
> +		.active_low             = 1,
> +		.debounce_interval      = 100,
> +	},
> +};
> +
> +static const struct gpio_keys_platform_data tink_buttons_pdata = {
> +	.buttons	= tink_buttons,
> +	.nbuttons	= ARRAY_SIZE(tink_buttons),
> +	.poll_interval  = 20,
> +	.rep		= 0,
> +	.name		= "mx100-keys",
> +};
> +
> +static struct gpiod_lookup_table tink_keys_table = {
> +	.dev_id = "gpio-keys-polled",
> +	.table = {
> +		GPIO_LOOKUP_IDX(TINK_GPIO_DRIVER_NAME, 60,
> +				NULL, 0, GPIO_ACTIVE_LOW),

Idem.

> +	}
> +};
> +
> +/* Board setup */
> +
> +static const struct dmi_system_id tink_systems[] __initconst = {
> +	{
> +		.matches = {
> +			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Cisco"),
> +			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "MX100-HW"),
> +		},
> +	},
> +	{} /* Terminating entry */
> +};
> +
> +static struct platform_device *tink_leds_pdev;
> +static struct platform_device *tink_keys_pdev;
> +
> +static struct platform_device * __init tink_create_dev(
> +	const char *name,
> +	const void *pdata,
> +	size_t sz)
> +{
> +	struct platform_device *pdev;
> +
> +	pdev = platform_device_register_data(NULL,
> +		name,
> +		PLATFORM_DEVID_NONE,
> +		pdata,
> +		sz);
> +
> +	if (IS_ERR(pdev))
> +		pr_err("failed registering %s: %ld\n", name, PTR_ERR(pdev));
> +
> +	return pdev;
> +}
> +
> +static int __init tink_board_init(void)
> +{
> +	if (!dmi_first_match(tink_systems))
> +                return -ENODEV;
> +
> +	/* We need to make sure that GPIO60 isn't set to native mode as is default since it's our 
> +	 * Reset Button. To do this, write to GPIO_USE_SEL2 to have GPIO60 set to GPIO mode.
> +	 * This is documented on page 1609 of the PCH datasheet, order number 327879-005US
> +	 */
> +	outl(inl(0x530) | BIT(28), 0x530);
> +
> +	gpiod_add_lookup_table(&tink_leds_table);
> +	gpiod_add_lookup_table(&tink_keys_table);
> +
> +	tink_leds_pdev = tink_create_dev(
> +		"leds-gpio",
> +		&tink_leds_pdata,
> +		sizeof(tink_leds_pdata));
> +
> +	tink_keys_pdev = tink_create_dev(
> +		"gpio-keys-polled",
> +		&tink_buttons_pdata,
> +		sizeof(tink_buttons_pdata));
> +
> +	return 0;
> +}
> +
> +static void __exit tink_board_exit(void)
> +{
> +	platform_device_unregister(tink_keys_pdev);
> +	platform_device_unregister(tink_leds_pdev);
> +	gpiod_remove_lookup_table(&tink_keys_table);
> +	gpiod_remove_lookup_table(&tink_leds_table);
> +}
> +
> +module_init(tink_board_init);
> +module_exit(tink_board_exit);
> +
> +MODULE_AUTHOR("Chris Blake <chrisrblake93@xxxxxxxxx>");
> +MODULE_DESCRIPTION("Cisco Meraki MX100 Platform Driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:meraki-mx100");
> +MODULE_DEVICE_TABLE(dmi, tink_systems);
> +MODULE_SOFTDEP("pre: platform:" TINK_GPIO_DRIVER_NAME);

This SOFTDEP should not be necessary, the platform devices
will be created regardless of the GPIO driver already having
loaded and if the request_gpio in the gpio_keys/_leds fails,
then it should fail with -EPROBE_DEFER and then the kernel
will retry to bind those drivers to the created platform-
devices later (until it succeeds).

So please give things a try without this line.

Regards,

Hans