linux-stable/drivers/pcmcia/soc_common.h
Gustavo A. R. Silva af741b0bad pcmcia: soc_common.h: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2020-03-28 07:52:13 +01:00

218 lines
5.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* linux/drivers/pcmcia/soc_common.h
*
* Copyright (C) 2000 John G Dorsey <john+@cs.cmu.edu>
*
* This file contains definitions for the PCMCIA support code common to
* integrated SOCs like the SA-11x0 and PXA2xx microprocessors.
*/
#ifndef _ASM_ARCH_PCMCIA
#define _ASM_ARCH_PCMCIA
/* include the world */
#include <linux/clk.h>
#include <linux/cpufreq.h>
#include <pcmcia/ss.h>
#include <pcmcia/cistpl.h>
struct device;
struct gpio_desc;
struct pcmcia_low_level;
struct regulator;
struct soc_pcmcia_regulator {
struct regulator *reg;
bool on;
};
/*
* This structure encapsulates per-socket state which we might need to
* use when responding to a Card Services query of some kind.
*/
struct soc_pcmcia_socket {
struct pcmcia_socket socket;
/*
* Info from low level handler
*/
unsigned int nr;
struct clk *clk;
/*
* Core PCMCIA state
*/
const struct pcmcia_low_level *ops;
unsigned int status;
socket_state_t cs_state;
unsigned short spd_io[MAX_IO_WIN];
unsigned short spd_mem[MAX_WIN];
unsigned short spd_attr[MAX_WIN];
struct resource res_skt;
struct resource res_io;
struct resource res_mem;
struct resource res_attr;
void __iomem *virt_io;
struct {
int gpio;
struct gpio_desc *desc;
unsigned int irq;
const char *name;
} stat[6];
#define SOC_STAT_CD 0 /* Card detect */
#define SOC_STAT_BVD1 1 /* BATDEAD / IOSTSCHG */
#define SOC_STAT_BVD2 2 /* BATWARN / IOSPKR */
#define SOC_STAT_RDY 3 /* Ready / Interrupt */
#define SOC_STAT_VS1 4 /* Voltage sense 1 */
#define SOC_STAT_VS2 5 /* Voltage sense 2 */
struct gpio_desc *gpio_reset;
struct gpio_desc *gpio_bus_enable;
struct soc_pcmcia_regulator vcc;
struct soc_pcmcia_regulator vpp;
unsigned int irq_state;
#ifdef CONFIG_CPU_FREQ
struct notifier_block cpufreq_nb;
#endif
struct timer_list poll_timer;
struct list_head node;
void *driver_data;
};
struct skt_dev_info {
int nskt;
struct soc_pcmcia_socket skt[];
};
struct pcmcia_state {
unsigned detect: 1,
ready: 1,
bvd1: 1,
bvd2: 1,
wrprot: 1,
vs_3v: 1,
vs_Xv: 1;
};
struct pcmcia_low_level {
struct module *owner;
/* first socket in system */
int first;
/* nr of sockets */
int nr;
int (*hw_init)(struct soc_pcmcia_socket *);
void (*hw_shutdown)(struct soc_pcmcia_socket *);
void (*socket_state)(struct soc_pcmcia_socket *, struct pcmcia_state *);
int (*configure_socket)(struct soc_pcmcia_socket *, const socket_state_t *);
/*
* Enable card status IRQs on (re-)initialisation. This can
* be called at initialisation, power management event, or
* pcmcia event.
*/
void (*socket_init)(struct soc_pcmcia_socket *);
/*
* Disable card status IRQs and PCMCIA bus on suspend.
*/
void (*socket_suspend)(struct soc_pcmcia_socket *);
/*
* Hardware specific timing routines.
* If provided, the get_timing routine overrides the SOC default.
*/
unsigned int (*get_timing)(struct soc_pcmcia_socket *, unsigned int, unsigned int);
int (*set_timing)(struct soc_pcmcia_socket *);
int (*show_timing)(struct soc_pcmcia_socket *, char *);
#ifdef CONFIG_CPU_FREQ
/*
* CPUFREQ support.
*/
int (*frequency_change)(struct soc_pcmcia_socket *, unsigned long, struct cpufreq_freqs *);
#endif
};
struct soc_pcmcia_timing {
unsigned short io;
unsigned short mem;
unsigned short attr;
};
extern void soc_common_pcmcia_get_timing(struct soc_pcmcia_socket *, struct soc_pcmcia_timing *);
void soc_pcmcia_init_one(struct soc_pcmcia_socket *skt,
const struct pcmcia_low_level *ops, struct device *dev);
void soc_pcmcia_remove_one(struct soc_pcmcia_socket *skt);
int soc_pcmcia_add_one(struct soc_pcmcia_socket *skt);
int soc_pcmcia_request_gpiods(struct soc_pcmcia_socket *skt);
void soc_common_cf_socket_state(struct soc_pcmcia_socket *skt,
struct pcmcia_state *state);
int soc_pcmcia_regulator_set(struct soc_pcmcia_socket *skt,
struct soc_pcmcia_regulator *r, int v);
#ifdef CONFIG_PCMCIA_DEBUG
extern void soc_pcmcia_debug(struct soc_pcmcia_socket *skt, const char *func,
int lvl, const char *fmt, ...);
#define debug(skt, lvl, fmt, arg...) \
soc_pcmcia_debug(skt, __func__, lvl, fmt , ## arg)
#else
#define debug(skt, lvl, fmt, arg...) do { } while (0)
#endif
/*
* The PC Card Standard, Release 7, section 4.13.4, says that twIORD
* has a minimum value of 165ns. Section 4.13.5 says that twIOWR has
* a minimum value of 165ns, as well. Section 4.7.2 (describing
* common and attribute memory write timing) says that twWE has a
* minimum value of 150ns for a 250ns cycle time (for 5V operation;
* see section 4.7.4), or 300ns for a 600ns cycle time (for 3.3V
* operation, also section 4.7.4). Section 4.7.3 says that taOE
* has a maximum value of 150ns for a 300ns cycle time (for 5V
* operation), or 300ns for a 600ns cycle time (for 3.3V operation).
*
* When configuring memory maps, Card Services appears to adopt the policy
* that a memory access time of "0" means "use the default." The default
* PCMCIA I/O command width time is 165ns. The default PCMCIA 5V attribute
* and memory command width time is 150ns; the PCMCIA 3.3V attribute and
* memory command width time is 300ns.
*/
#define SOC_PCMCIA_IO_ACCESS (165)
#define SOC_PCMCIA_5V_MEM_ACCESS (150)
#define SOC_PCMCIA_3V_MEM_ACCESS (300)
#define SOC_PCMCIA_ATTR_MEM_ACCESS (300)
/*
* The socket driver actually works nicely in interrupt-driven form,
* so the (relatively infrequent) polling is "just to be sure."
*/
#define SOC_PCMCIA_POLL_PERIOD (2*HZ)
/* I/O pins replacing memory pins
* (PCMCIA System Architecture, 2nd ed., by Don Anderson, p.75)
*
* These signals change meaning when going from memory-only to
* memory-or-I/O interface:
*/
#define iostschg bvd1
#define iospkr bvd2
#endif