fmc: Delete the FMC subsystem

The FMC subsystem was created in 2012 with the ambition to
drive development of drivers for this hardware upstream.

The current implementation has architectural flaws and would
need to be revamped using real hardware to something that can
reuse existing kernel abstractions in the subsystems for e.g.
I2C, FPGA and GPIO.

We have concluded that for the mainline kernel it will be
better to delete the subsystem and start over with a clean
slate when/if an active maintainer steps up.

For details see:
https://lkml.org/lkml/2018/10/29/534

Suggested-by: Federico Vaga <federico.vaga@cern.ch>
Cc: Pat Riehecky <riehecky@fnal.gov>
Acked-by: Alessandro Rubini <rubini@gnudd.com>
Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 0 insertions, 271 deletions

diff --git a/include/linux/fmc.h b/include/linux/fmc.h
deleted file mode 100644
index 8661a46a676f..000000000000
--- a/include/linux/fmc.h
+++ /dev/null
@@ -1,271 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
-/*
- * Copyright (C) 2012 CERN (www.cern.ch)
- * Author: Alessandro Rubini <rubini@gnudd.com>
- *
- * This work is part of the White Rabbit project, a research effort led
- * by CERN, the European Institute for Nuclear Research.
- */
-#ifndef __LINUX_FMC_H__
-#define __LINUX_FMC_H__
-#include <linux/types.h>
-#include <linux/moduleparam.h>
-#include <linux/device.h>
-#include <linux/list.h>
-#include <linux/interrupt.h>
-#include <linux/io.h>
-
-struct fmc_device;
-struct fmc_driver;
-
-/*
- * This bus abstraction is developed separately from drivers, so we need
- * to check the version of the data structures we receive.
- */
-
-#define FMC_MAJOR	3
-#define FMC_MINOR	0
-#define FMC_VERSION	((FMC_MAJOR << 16) | FMC_MINOR)
-#define __FMC_MAJOR(x)	((x) >> 16)
-#define __FMC_MINOR(x)	((x) & 0xffff)
-
-/*
- * The device identification, as defined by the IPMI FRU (Field Replaceable
- * Unit) includes four different strings to describe the device. Here we
- * only match the "Board Manufacturer" and the "Board Product Name",
- * ignoring the "Board Serial Number" and "Board Part Number". All 4 are
- * expected to be strings, so they are treated as zero-terminated C strings.
- * Unspecified string (NULL) means "any", so if both are unspecified this
- * is a catch-all driver. So null entries are allowed and we use array
- * and length. This is unlike pci and usb that use null-terminated arrays
- */
-struct fmc_fru_id {
-	char *manufacturer;
-	char *product_name;
-};
-
-/*
- * If the FPGA is already programmed (think Etherbone or the second
- * SVEC slot), we can match on SDB devices in the memory image. This
- * match uses an array of devices that must all be present, and the
- * match is based on vendor and device only. Further checks are expected
- * to happen in the probe function. Zero means "any" and catch-all is allowed.
- */
-struct fmc_sdb_one_id {
-	uint64_t vendor;
-	uint32_t device;
-};
-struct fmc_sdb_id {
-	struct fmc_sdb_one_id *cores;
-	int cores_nr;
-};
-
-struct fmc_device_id {
-	struct fmc_fru_id *fru_id;
-	int fru_id_nr;
-	struct fmc_sdb_id *sdb_id;
-	int sdb_id_nr;
-};
-
-/* This sizes the module_param_array used by generic module parameters */
-#define FMC_MAX_CARDS 32
-
-/* The driver is a pretty simple thing */
-struct fmc_driver {
-	unsigned long version;
-	struct device_driver driver;
-	int (*probe)(struct fmc_device *);
-	int (*remove)(struct fmc_device *);
-	const struct fmc_device_id id_table;
-	/* What follows is for generic module parameters */
-	int busid_n;
-	int busid_val[FMC_MAX_CARDS];
-	int gw_n;
-	char *gw_val[FMC_MAX_CARDS];
-};
-#define to_fmc_driver(x) container_of((x), struct fmc_driver, driver)
-
-/* These are the generic parameters, that drivers may instantiate */
-#define FMC_PARAM_BUSID(_d) \
-    module_param_array_named(busid, _d.busid_val, int, &_d.busid_n, 0444)
-#define FMC_PARAM_GATEWARE(_d) \
-    module_param_array_named(gateware, _d.gw_val, charp, &_d.gw_n, 0444)
-
-/*
- * Drivers may need to configure gpio pins in the carrier. To read input
- * (a very uncommon operation, and definitely not in the hot paths), just
- * configure one gpio only and get 0 or 1 as retval of the config method
- */
-struct fmc_gpio {
-	char *carrier_name; /* name or NULL for virtual pins */
-	int gpio;
-	int _gpio;	/* internal use by the carrier */
-	int mode;	/* GPIOF_DIR_OUT etc */
-	int irqmode;	/* IRQF_TRIGGER_LOW and so on */
-};
-
-/* The numbering of gpio pins allows access to raw pins or virtual roles */
-#define FMC_GPIO_RAW(x)		(x)		/* 4096 of them */
-#define __FMC_GPIO_IS_RAW(x)	((x) < 0x1000)
-#define FMC_GPIO_IRQ(x)		((x) + 0x1000)	/*  256 of them */
-#define FMC_GPIO_LED(x)		((x) + 0x1100)	/*  256 of them */
-#define FMC_GPIO_KEY(x)		((x) + 0x1200)	/*  256 of them */
-#define FMC_GPIO_TP(x)		((x) + 0x1300)	/*  256 of them */
-#define FMC_GPIO_USER(x)	((x) + 0x1400)	/*  256 of them */
-/* We may add SCL and SDA, or other roles if the need arises */
-
-/*
- * These are similar to the legacy Linux GPIO defines from <linux/gpio.h>
- * but in fact FMC has its own GPIO handling and is not using the Linux
- * GPIO subsystem.
- */
-#define GPIOF_DIR_OUT   (0 << 0)
-#define GPIOF_DIR_IN    (1 << 0)
-#define GPIOF_INIT_LOW  (0 << 1)
-#define GPIOF_INIT_HIGH (1 << 1)
-
-/*
- * The operations are offered by each carrier and should make driver
- * design completely independent of the carrier. Named GPIO pins may be
- * the exception.
- */
-struct fmc_operations {
-	uint32_t (*read32)(struct fmc_device *fmc, int offset);
-	void (*write32)(struct fmc_device *fmc, uint32_t value, int offset);
-	int (*validate)(struct fmc_device *fmc, struct fmc_driver *drv);
-	int (*reprogram_raw)(struct fmc_device *f, struct fmc_driver *d,
-			     void *gw, unsigned long len);
-	int (*reprogram)(struct fmc_device *f, struct fmc_driver *d, char *gw);
-	int (*irq_request)(struct fmc_device *fmc, irq_handler_t h,
-			   char *name, int flags);
-	void (*irq_ack)(struct fmc_device *fmc);
-	int (*irq_free)(struct fmc_device *fmc);
-	int (*gpio_config)(struct fmc_device *fmc, struct fmc_gpio *gpio,
-			   int ngpio);
-	int (*read_ee)(struct fmc_device *fmc, int pos, void *d, int l);
-	int (*write_ee)(struct fmc_device *fmc, int pos, const void *d, int l);
-};
-
-/* Prefer this helper rather than calling of fmc->reprogram directly */
-int fmc_reprogram_raw(struct fmc_device *fmc, struct fmc_driver *d,
-		      void *gw, unsigned long len, int sdb_entry);
-extern int fmc_reprogram(struct fmc_device *f, struct fmc_driver *d, char *gw,
-		     int sdb_entry);
-
-/*
- * The device reports all information needed to access hw.
- *
- * If we have eeprom_len and not contents, the core reads it.
- * Then, parsing of identifiers is done by the core which fills fmc_fru_id..
- * Similarly a device that must be matched based on SDB cores must
- * fill the entry point and the core will scan the bus (FIXME: sdb match)
- */
-struct fmc_device {
-	unsigned long version;
-	unsigned long flags;
-	struct module *owner;		/* char device must pin it */
-	struct fmc_fru_id id;		/* for EEPROM-based match */
-	struct fmc_operations *op;	/* carrier-provided */
-	int irq;			/* according to host bus. 0 == none */
-	int eeprom_len;			/* Usually 8kB, may be less */
-	int eeprom_addr;		/* 0x50, 0x52 etc */
-	uint8_t *eeprom;		/* Full contents or leading part */
-	char *carrier_name;		/* "SPEC" or similar, for special use */
-	void *carrier_data;		/* "struct spec *" or equivalent */
-	__iomem void *fpga_base;	/* May be NULL (Etherbone) */
-	__iomem void *slot_base;	/* Set by the driver */
-	struct fmc_device **devarray;	/* Allocated by the bus */
-	int slot_id;			/* Index in the slot array */
-	int nr_slots;			/* Number of slots in this carrier */
-	unsigned long memlen;		/* Used for the char device */
-	struct device dev;		/* For Linux use */
-	struct device *hwdev;		/* The underlying hardware device */
-	unsigned long sdbfs_entry;
-	struct sdb_array *sdb;
-	uint32_t device_id;		/* Filled by the device */
-	char *mezzanine_name;		/* Defaults to ``fmc'' */
-	void *mezzanine_data;
-
-	struct dentry *dbg_dir;
-	struct dentry *dbg_sdb_dump;
-};
-#define to_fmc_device(x) container_of((x), struct fmc_device, dev)
-
-#define FMC_DEVICE_HAS_GOLDEN		1
-#define FMC_DEVICE_HAS_CUSTOM		2
-#define FMC_DEVICE_NO_MEZZANINE		4
-#define FMC_DEVICE_MATCH_SDB		8 /* fmc-core must scan sdb in fpga */
-
-/*
- * If fpga_base can be used, the carrier offers no readl/writel methods, and
- * this expands to a single, fast, I/O access.
- */
-static inline uint32_t fmc_readl(struct fmc_device *fmc, int offset)
-{
-	if (unlikely(fmc->op->read32))
-		return fmc->op->read32(fmc, offset);
-	return readl(fmc->fpga_base + offset);
-}
-static inline void fmc_writel(struct fmc_device *fmc, uint32_t val, int off)
-{
-	if (unlikely(fmc->op->write32))
-		fmc->op->write32(fmc, val, off);
-	else
-		writel(val, fmc->fpga_base + off);
-}
-
-/* pci-like naming */
-static inline void *fmc_get_drvdata(const struct fmc_device *fmc)
-{
-	return dev_get_drvdata(&fmc->dev);
-}
-
-static inline void fmc_set_drvdata(struct fmc_device *fmc, void *data)
-{
-	dev_set_drvdata(&fmc->dev, data);
-}
-
-struct fmc_gateware {
-	void *bitstream;
-	unsigned long len;
-};
-
-/* The 5 access points */
-extern int fmc_driver_register(struct fmc_driver *drv);
-extern void fmc_driver_unregister(struct fmc_driver *drv);
-extern int fmc_device_register(struct fmc_device *tdev);
-extern int fmc_device_register_gw(struct fmc_device *tdev,
-				  struct fmc_gateware *gw);
-extern void fmc_device_unregister(struct fmc_device *tdev);
-
-/* Three more for device sets, all driven by the same FPGA */
-extern int fmc_device_register_n(struct fmc_device **devs, int n);
-extern int fmc_device_register_n_gw(struct fmc_device **devs, int n,
-				    struct fmc_gateware *gw);
-extern void fmc_device_unregister_n(struct fmc_device **devs, int n);
-
-/* Internal cross-calls between files; not exported to other modules */
-extern int fmc_match(struct device *dev, struct device_driver *drv);
-extern int fmc_fill_id_info(struct fmc_device *fmc);
-extern void fmc_free_id_info(struct fmc_device *fmc);
-extern void fmc_dump_eeprom(const struct fmc_device *fmc);
-
-/* helpers for FMC operations */
-extern int fmc_irq_request(struct fmc_device *fmc, irq_handler_t h,
-			   char *name, int flags);
-extern void fmc_irq_free(struct fmc_device *fmc);
-extern void fmc_irq_ack(struct fmc_device *fmc);
-extern int fmc_validate(struct fmc_device *fmc, struct fmc_driver *drv);
-extern int fmc_gpio_config(struct fmc_device *fmc, struct fmc_gpio *gpio,
-			   int ngpio);
-extern int fmc_read_ee(struct fmc_device *fmc, int pos, void *d, int l);
-extern int fmc_write_ee(struct fmc_device *fmc, int pos, const void *d, int l);
-
-/* helpers for FMC operations */
-extern int fmc_irq_request(struct fmc_device *fmc, irq_handler_t h,
-			   char *name, int flags);
-extern void fmc_irq_free(struct fmc_device *fmc);
-extern void fmc_irq_ack(struct fmc_device *fmc);
-extern int fmc_validate(struct fmc_device *fmc, struct fmc_driver *drv);
-
-#endif /* __LINUX_FMC_H__ */