Re: [PATCH v5 2/4] leds: simatic-ipc-leds: add new driver for Siemens Industial PCs

From: Henning Schild
Date: Fri May 13 2022 - 15:40:43 EST

Am Mon, 13 Dec 2021 13:05:00 +0100
schrieb Henning Schild <henning.schild@xxxxxxxxxxx>:

> This driver adds initial support for several devices from Siemens. It
> is based on a platform driver introduced in an earlier commit.
>
> One of the supported machines has GPIO connected LEDs, here we poke
> GPIO memory directly because pinctrl does not come up.
>
> Signed-off-by: Henning Schild <henning.schild@xxxxxxxxxxx>
> ---
> drivers/leds/Kconfig | 3 +
> drivers/leds/Makefile | 3 +
> drivers/leds/simple/Kconfig | 11 ++
> drivers/leds/simple/Makefile | 2 +
> drivers/leds/simple/simatic-ipc-leds.c | 202
> +++++++++++++++++++++++++ 5 files changed, 221 insertions(+)
> create mode 100644 drivers/leds/simple/Kconfig
> create mode 100644 drivers/leds/simple/Makefile
> create mode 100644 drivers/leds/simple/simatic-ipc-leds.c
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index ed800f5da7d8..ac6688d7a3f4 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -879,4 +879,7 @@ source "drivers/leds/flash/Kconfig"
> comment "LED Triggers"
> source "drivers/leds/trigger/Kconfig"
>
> +comment "Simple LED drivers"
> +source "drivers/leds/simple/Kconfig"
> +
> endif # NEW_LEDS
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index c636ec069612..1a719caf14c0 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -105,3 +105,6 @@ obj-$(CONFIG_LEDS_TRIGGERS) +=
> trigger/
> # LED Blink
> obj-y += blink/
> +
> +# Simple LED drivers
> +obj-y += simple/
> diff --git a/drivers/leds/simple/Kconfig b/drivers/leds/simple/Kconfig
> new file mode 100644
> index 000000000000..9f6a68336659
> --- /dev/null
> +++ b/drivers/leds/simple/Kconfig
> @@ -0,0 +1,11 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +config LEDS_SIEMENS_SIMATIC_IPC
> + tristate "LED driver for Siemens Simatic IPCs"
> + depends on LEDS_CLASS
> + depends on SIEMENS_SIMATIC_IPC

Trying to bring this into distros i think this one should rather be
"select SIEMENS_SIMATIC_IPC" and the same thought goes for wdt.

Users care about enabling a feature and maybe not too much about having
to enable infra, enabling SIEMENS_SIMATIC_IPC is just infra and useless
without LEDS_SIEMENS_SIMATIC_IPC and/or SIEMENS_SIMATIC_IPC_WDT.

So those two should probably "select" and not "depend".

I will send a patch, feel free to tell me that i am wrong and teach me
about how deps should work.

regards,
Henning

> + help
> + This option enables support for the LEDs of several
> Industrial PCs
> + from Siemens.
> +
> + To compile this driver as a module, choose M here: the
> module
> + will be called simatic-ipc-leds.
> diff --git a/drivers/leds/simple/Makefile
> b/drivers/leds/simple/Makefile new file mode 100644
> index 000000000000..8481f1e9e360
> --- /dev/null
> +++ b/drivers/leds/simple/Makefile
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0
> +obj-$(CONFIG_LEDS_SIEMENS_SIMATIC_IPC) += simatic-ipc-leds.o
> diff --git a/drivers/leds/simple/simatic-ipc-leds.c
> b/drivers/leds/simple/simatic-ipc-leds.c new file mode 100644
> index 000000000000..ff2c96e73241
> --- /dev/null
> +++ b/drivers/leds/simple/simatic-ipc-leds.c
> @@ -0,0 +1,202 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Siemens SIMATIC IPC driver for LEDs
> + *
> + * Copyright (c) Siemens AG, 2018-2021
> + *
> + * Authors:
> + * Henning Schild <henning.schild@xxxxxxxxxxx>
> + * Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
> + * Gerd Haeussler <gerd.haeussler.ext@xxxxxxxxxxx>
> + */
> +
> +#include <linux/ioport.h>
> +#include <linux/kernel.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +#include <linux/platform_data/x86/simatic-ipc-base.h>
> +#include <linux/platform_device.h>
> +#include <linux/sizes.h>
> +#include <linux/spinlock.h>
> +
> +#define SIMATIC_IPC_LED_PORT_BASE 0x404E
> +
> +struct simatic_ipc_led {
> + unsigned int value; /* mask for io and offset for mem */
> + char *name;
> + struct led_classdev cdev;
> +};
> +
> +static struct simatic_ipc_led simatic_ipc_leds_io[] = {
> + {1 << 15, "green:" LED_FUNCTION_STATUS "-1" },
> + {1 << 7, "yellow:" LED_FUNCTION_STATUS "-1" },
> + {1 << 14, "red:" LED_FUNCTION_STATUS "-2" },
> + {1 << 6, "yellow:" LED_FUNCTION_STATUS "-2" },
> + {1 << 13, "red:" LED_FUNCTION_STATUS "-3" },
> + {1 << 5, "yellow:" LED_FUNCTION_STATUS "-3" },
> + { }
> +};
> +
> +/* the actual start will be discovered with PCI, 0 is a placeholder
> */ +struct resource simatic_ipc_led_mem_res = DEFINE_RES_MEM_NAMED(0,
> SZ_4K, KBUILD_MODNAME); +
> +static void *simatic_ipc_led_memory;
> +
> +static struct simatic_ipc_led simatic_ipc_leds_mem[] = {
> + {0x500 + 0x1A0, "red:" LED_FUNCTION_STATUS "-1"},
> + {0x500 + 0x1A8, "green:" LED_FUNCTION_STATUS "-1"},
> + {0x500 + 0x1C8, "red:" LED_FUNCTION_STATUS "-2"},
> + {0x500 + 0x1D0, "green:" LED_FUNCTION_STATUS "-2"},
> + {0x500 + 0x1E0, "red:" LED_FUNCTION_STATUS "-3"},
> + {0x500 + 0x198, "green:" LED_FUNCTION_STATUS "-3"},
> + { }
> +};
> +
> +static struct resource simatic_ipc_led_io_res =
> + DEFINE_RES_IO_NAMED(SIMATIC_IPC_LED_PORT_BASE, SZ_2,
> KBUILD_MODNAME); +
> +static DEFINE_SPINLOCK(reg_lock);
> +
> +static inline struct simatic_ipc_led *cdev_to_led(struct
> led_classdev *led_cd) +{
> + return container_of(led_cd, struct simatic_ipc_led, cdev);
> +}
> +
> +static void simatic_ipc_led_set_io(struct led_classdev *led_cd,
> + enum led_brightness brightness)
> +{
> + struct simatic_ipc_led *led = cdev_to_led(led_cd);
> + unsigned long flags;
> + unsigned int val;
> +
> + spin_lock_irqsave(&reg_lock, flags);
> +
> + val = inw(SIMATIC_IPC_LED_PORT_BASE);
> + if (brightness == LED_OFF)
> + outw(val | led->value, SIMATIC_IPC_LED_PORT_BASE);
> + else
> + outw(val & ~led->value, SIMATIC_IPC_LED_PORT_BASE);
> +
> + spin_unlock_irqrestore(&reg_lock, flags);
> +}
> +
> +static enum led_brightness simatic_ipc_led_get_io(struct
> led_classdev *led_cd) +{
> + struct simatic_ipc_led *led = cdev_to_led(led_cd);
> +
> + return inw(SIMATIC_IPC_LED_PORT_BASE) & led->value ? LED_OFF
> : led_cd->max_brightness; +}
> +
> +static void simatic_ipc_led_set_mem(struct led_classdev *led_cd,
> + enum led_brightness brightness)
> +{
> + struct simatic_ipc_led *led = cdev_to_led(led_cd);
> +
> + u32 *p;
> +
> + p = simatic_ipc_led_memory + led->value;
> + *p = (*p & ~1) | (brightness == LED_OFF);
> +}
> +
> +static enum led_brightness simatic_ipc_led_get_mem(struct
> led_classdev *led_cd) +{
> + struct simatic_ipc_led *led = cdev_to_led(led_cd);
> +
> + u32 *p;
> +
> + p = simatic_ipc_led_memory + led->value;
> + return (*p & 1) ? LED_OFF : led_cd->max_brightness;
> +}
> +
> +static int simatic_ipc_leds_probe(struct platform_device *pdev)
> +{
> + const struct simatic_ipc_platform *plat =
> pdev->dev.platform_data;
> + struct device *dev = &pdev->dev;
> + struct simatic_ipc_led *ipcled;
> + struct led_classdev *cdev;
> + struct resource *res;
> + int err, type;
> + u32 *p;
> +
> + switch (plat->devmode) {
> + case SIMATIC_IPC_DEVICE_227D:
> + case SIMATIC_IPC_DEVICE_427E:
> + res = &simatic_ipc_led_io_res;
> + ipcled = simatic_ipc_leds_io;
> + /* on 227D the two bytes work the other way araound
> */
> + if (plat->devmode == SIMATIC_IPC_DEVICE_227D) {
> + while (ipcled->value) {
> + ipcled->value =
> swab16(ipcled->value);
> + ipcled++;
> + }
> + ipcled = simatic_ipc_leds_io;
> + }
> + type = IORESOURCE_IO;
> + if (!devm_request_region(dev, res->start,
> resource_size(res), KBUILD_MODNAME)) {
> + dev_err(dev, "Unable to register IO resource
> at %pR\n", res);
> + return -EBUSY;
> + }
> + break;
> + case SIMATIC_IPC_DEVICE_127E:
> + res = &simatic_ipc_led_mem_res;
> + ipcled = simatic_ipc_leds_mem;
> + type = IORESOURCE_MEM;
> +
> + /* get GPIO base from PCI */
> + res->start = simatic_ipc_get_membase0(PCI_DEVFN(13,
> 0));
> + if (res->start == 0)
> + return -ENODEV;
> +
> + /* do the final address calculation */
> + res->start = res->start + (0xC5 << 16);
> + res->end += res->start;
> +
> + simatic_ipc_led_memory = devm_ioremap_resource(dev,
> res);
> + if (IS_ERR(simatic_ipc_led_memory))
> + return PTR_ERR(simatic_ipc_led_memory);
> +
> + /* initialize power/watchdog LED */
> + p = simatic_ipc_led_memory + 0x500 + 0x1D8; /*
> PM_WDT_OUT */
> + *p = (*p & ~1);
> + p = simatic_ipc_led_memory + 0x500 + 0x1C0; /*
> PM_BIOS_BOOT_N */
> + *p = (*p | 1);
> +
> + break;
> + default:
> + return -ENODEV;
> + }
> +
> + while (ipcled->value) {
> + cdev = &ipcled->cdev;
> + if (type == IORESOURCE_MEM) {
> + cdev->brightness_set =
> simatic_ipc_led_set_mem;
> + cdev->brightness_get =
> simatic_ipc_led_get_mem;
> + } else {
> + cdev->brightness_set =
> simatic_ipc_led_set_io;
> + cdev->brightness_get =
> simatic_ipc_led_get_io;
> + }
> + cdev->max_brightness = LED_ON;
> + cdev->name = ipcled->name;
> +
> + err = devm_led_classdev_register(dev, cdev);
> + if (err < 0)
> + return err;
> + ipcled++;
> + }
> +
> + return 0;
> +}
> +
> +static struct platform_driver simatic_ipc_led_driver = {
> + .probe = simatic_ipc_leds_probe,
> + .driver = {
> + .name = KBUILD_MODNAME,
> + }
> +};
> +
> +module_platform_driver(simatic_ipc_led_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:" KBUILD_MODNAME);
> +MODULE_AUTHOR("Henning Schild <henning.schild@xxxxxxxxxxx>");