linux/drivers/pcmcia/at91_cf.c

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/*
* at91_cf.c -- AT91 CompactFlash controller driver
*
* Copyright (C) 2005 David Brownell
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <pcmcia/ss.h>
#include <mach/hardware.h>
#include <asm/io.h>
#include <asm/sizes.h>
#include <asm/gpio.h>
#include <mach/board.h>
#include <mach/at91rm9200_mc.h>
/*
* A0..A10 work in each range; A23 indicates I/O space; A25 is CFRNW;
* some other bit in {A24,A22..A11} is nREG to flag memory access
* (vs attributes). So more than 2KB/region would just be waste.
* Note: These are offsets from the physical base address.
*/
#define CF_ATTR_PHYS (0)
#define CF_IO_PHYS (1 << 23)
#define CF_MEM_PHYS (0x017ff800)
/*--------------------------------------------------------------------------*/
static const char driver_name[] = "at91_cf";
struct at91_cf_socket {
struct pcmcia_socket socket;
unsigned present:1;
struct platform_device *pdev;
struct at91_cf_data *board;
unsigned long phys_baseaddr;
};
#define SZ_2K (2 * SZ_1K)
static inline int at91_cf_present(struct at91_cf_socket *cf)
{
return !gpio_get_value(cf->board->det_pin);
}
/*--------------------------------------------------------------------------*/
static int at91_cf_ss_init(struct pcmcia_socket *s)
{
return 0;
}
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:55:46 +02:00
static irqreturn_t at91_cf_irq(int irq, void *_cf)
{
struct at91_cf_socket *cf = _cf;
if (irq == cf->board->det_pin) {
unsigned present = at91_cf_present(cf);
/* kick pccard as needed */
if (present != cf->present) {
cf->present = present;
pr_debug("%s: card %s\n", driver_name,
present ? "present" : "gone");
pcmcia_parse_events(&cf->socket, SS_DETECT);
}
}
return IRQ_HANDLED;
}
static int at91_cf_get_status(struct pcmcia_socket *s, u_int *sp)
{
struct at91_cf_socket *cf;
if (!sp)
return -EINVAL;
cf = container_of(s, struct at91_cf_socket, socket);
/* NOTE: CF is always 3VCARD */
if (at91_cf_present(cf)) {
int rdy = cf->board->irq_pin; /* RDY/nIRQ */
int vcc = cf->board->vcc_pin;
*sp = SS_DETECT | SS_3VCARD;
if (!rdy || gpio_get_value(rdy))
*sp |= SS_READY;
if (!vcc || gpio_get_value(vcc))
*sp |= SS_POWERON;
} else
*sp = 0;
return 0;
}
static int
at91_cf_set_socket(struct pcmcia_socket *sock, struct socket_state_t *s)
{
struct at91_cf_socket *cf;
cf = container_of(sock, struct at91_cf_socket, socket);
/* switch Vcc if needed and possible */
if (cf->board->vcc_pin) {
switch (s->Vcc) {
case 0:
gpio_set_value(cf->board->vcc_pin, 0);
break;
case 33:
gpio_set_value(cf->board->vcc_pin, 1);
break;
default:
return -EINVAL;
}
}
/* toggle reset if needed */
gpio_set_value(cf->board->rst_pin, s->flags & SS_RESET);
pr_debug("%s: Vcc %d, io_irq %d, flags %04x csc %04x\n",
driver_name, s->Vcc, s->io_irq, s->flags, s->csc_mask);
return 0;
}
static int at91_cf_ss_suspend(struct pcmcia_socket *s)
{
return at91_cf_set_socket(s, &dead_socket);
}
/* we already mapped the I/O region */
static int at91_cf_set_io_map(struct pcmcia_socket *s, struct pccard_io_map *io)
{
struct at91_cf_socket *cf;
u32 csr;
cf = container_of(s, struct at91_cf_socket, socket);
io->flags &= (MAP_ACTIVE | MAP_16BIT | MAP_AUTOSZ);
/*
* Use 16 bit accesses unless/until we need 8-bit i/o space.
*/
csr = at91_sys_read(AT91_SMC_CSR(cf->board->chipselect)) & ~AT91_SMC_DBW;
/*
* NOTE: this CF controller ignores IOIS16, so we can't really do
* MAP_AUTOSZ. The 16bit mode allows single byte access on either
* D0-D7 (even addr) or D8-D15 (odd), so it's close enough for many
* purposes (and handles ide-cs).
*
* The 8bit mode is needed for odd byte access on D0-D7. It seems
* some cards only like that way to get at the odd byte, despite
* CF 3.0 spec table 35 also giving the D8-D15 option.
*/
if (!(io->flags & (MAP_16BIT | MAP_AUTOSZ))) {
csr |= AT91_SMC_DBW_8;
pr_debug("%s: 8bit i/o bus\n", driver_name);
} else {
csr |= AT91_SMC_DBW_16;
pr_debug("%s: 16bit i/o bus\n", driver_name);
}
at91_sys_write(AT91_SMC_CSR(cf->board->chipselect), csr);
io->start = cf->socket.io_offset;
io->stop = io->start + SZ_2K - 1;
return 0;
}
/* pcmcia layer maps/unmaps mem regions */
static int
at91_cf_set_mem_map(struct pcmcia_socket *s, struct pccard_mem_map *map)
{
struct at91_cf_socket *cf;
if (map->card_start)
return -EINVAL;
cf = container_of(s, struct at91_cf_socket, socket);
map->flags &= (MAP_ACTIVE | MAP_ATTRIB | MAP_16BIT);
if (map->flags & MAP_ATTRIB)
map->static_start = cf->phys_baseaddr + CF_ATTR_PHYS;
else
map->static_start = cf->phys_baseaddr + CF_MEM_PHYS;
return 0;
}
static struct pccard_operations at91_cf_ops = {
.init = at91_cf_ss_init,
.suspend = at91_cf_ss_suspend,
.get_status = at91_cf_get_status,
.set_socket = at91_cf_set_socket,
.set_io_map = at91_cf_set_io_map,
.set_mem_map = at91_cf_set_mem_map,
};
/*--------------------------------------------------------------------------*/
static int __init at91_cf_probe(struct platform_device *pdev)
{
struct at91_cf_socket *cf;
struct at91_cf_data *board = pdev->dev.platform_data;
struct resource *io;
int status;
if (!board || !board->det_pin || !board->rst_pin)
return -ENODEV;
io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!io)
return -ENODEV;
cf = kzalloc(sizeof *cf, GFP_KERNEL);
if (!cf)
return -ENOMEM;
cf->board = board;
cf->pdev = pdev;
cf->phys_baseaddr = io->start;
platform_set_drvdata(pdev, cf);
/* must be a GPIO; ergo must trigger on both edges */
status = gpio_request(board->det_pin, "cf_det");
if (status < 0)
goto fail0;
status = request_irq(board->det_pin, at91_cf_irq, 0, driver_name, cf);
if (status < 0)
goto fail00;
device_init_wakeup(&pdev->dev, 1);
status = gpio_request(board->rst_pin, "cf_rst");
if (status < 0)
goto fail0a;
if (board->vcc_pin) {
status = gpio_request(board->vcc_pin, "cf_vcc");
if (status < 0)
goto fail0b;
}
/*
* The card driver will request this irq later as needed.
* but it causes lots of "irqNN: nobody cared" messages
* unless we report that we handle everything (sigh).
* (Note: DK board doesn't wire the IRQ pin...)
*/
if (board->irq_pin) {
status = gpio_request(board->irq_pin, "cf_irq");
if (status < 0)
goto fail0c;
status = request_irq(board->irq_pin, at91_cf_irq,
IRQF_SHARED, driver_name, cf);
if (status < 0)
goto fail0d;
cf->socket.pci_irq = board->irq_pin;
} else
cf->socket.pci_irq = nr_irqs + 1;
/* pcmcia layer only remaps "real" memory not iospace */
cf->socket.io_offset = (unsigned long)
ioremap(cf->phys_baseaddr + CF_IO_PHYS, SZ_2K);
if (!cf->socket.io_offset) {
status = -ENXIO;
goto fail1;
}
/* reserve chip-select regions */
if (!request_mem_region(io->start, io->end + 1 - io->start,
driver_name)) {
status = -ENXIO;
goto fail1;
}
pr_info("%s: irqs det #%d, io #%d\n", driver_name,
board->det_pin, board->irq_pin);
cf->socket.owner = THIS_MODULE;
cf->socket.dev.parent = &pdev->dev;
cf->socket.ops = &at91_cf_ops;
cf->socket.resource_ops = &pccard_static_ops;
cf->socket.features = SS_CAP_PCCARD | SS_CAP_STATIC_MAP
| SS_CAP_MEM_ALIGN;
cf->socket.map_size = SZ_2K;
cf->socket.io[0].res = io;
status = pcmcia_register_socket(&cf->socket);
if (status < 0)
goto fail2;
return 0;
fail2:
release_mem_region(io->start, io->end + 1 - io->start);
fail1:
if (cf->socket.io_offset)
iounmap((void __iomem *) cf->socket.io_offset);
if (board->irq_pin) {
free_irq(board->irq_pin, cf);
fail0d:
gpio_free(board->irq_pin);
}
fail0c:
if (board->vcc_pin)
gpio_free(board->vcc_pin);
fail0b:
gpio_free(board->rst_pin);
fail0a:
device_init_wakeup(&pdev->dev, 0);
free_irq(board->det_pin, cf);
fail00:
gpio_free(board->det_pin);
fail0:
kfree(cf);
return status;
}
static int __exit at91_cf_remove(struct platform_device *pdev)
{
struct at91_cf_socket *cf = platform_get_drvdata(pdev);
struct at91_cf_data *board = cf->board;
struct resource *io = cf->socket.io[0].res;
pcmcia_unregister_socket(&cf->socket);
release_mem_region(io->start, io->end + 1 - io->start);
iounmap((void __iomem *) cf->socket.io_offset);
if (board->irq_pin) {
free_irq(board->irq_pin, cf);
gpio_free(board->irq_pin);
}
if (board->vcc_pin)
gpio_free(board->vcc_pin);
gpio_free(board->rst_pin);
device_init_wakeup(&pdev->dev, 0);
free_irq(board->det_pin, cf);
gpio_free(board->det_pin);
kfree(cf);
return 0;
}
#ifdef CONFIG_PM
static int at91_cf_suspend(struct platform_device *pdev, pm_message_t mesg)
{
struct at91_cf_socket *cf = platform_get_drvdata(pdev);
struct at91_cf_data *board = cf->board;
pcmcia_socket_dev_suspend(&pdev->dev, mesg);
if (device_may_wakeup(&pdev->dev)) {
enable_irq_wake(board->det_pin);
if (board->irq_pin)
enable_irq_wake(board->irq_pin);
}
return 0;
}
static int at91_cf_resume(struct platform_device *pdev)
{
struct at91_cf_socket *cf = platform_get_drvdata(pdev);
struct at91_cf_data *board = cf->board;
if (device_may_wakeup(&pdev->dev)) {
disable_irq_wake(board->det_pin);
if (board->irq_pin)
disable_irq_wake(board->irq_pin);
}
pcmcia_socket_dev_resume(&pdev->dev);
return 0;
}
#else
#define at91_cf_suspend NULL
#define at91_cf_resume NULL
#endif
static struct platform_driver at91_cf_driver = {
.driver = {
.name = (char *) driver_name,
.owner = THIS_MODULE,
},
.remove = __exit_p(at91_cf_remove),
.suspend = at91_cf_suspend,
.resume = at91_cf_resume,
};
/*--------------------------------------------------------------------------*/
static int __init at91_cf_init(void)
{
return platform_driver_probe(&at91_cf_driver, at91_cf_probe);
}
module_init(at91_cf_init);
static void __exit at91_cf_exit(void)
{
platform_driver_unregister(&at91_cf_driver);
}
module_exit(at91_cf_exit);
MODULE_DESCRIPTION("AT91 Compact Flash Driver");
MODULE_AUTHOR("David Brownell");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:at91_cf");