linux/drivers/parport/parport_amiga.c
Uwe Kleine-König 73fedc31fe parport: amiga: Mark driver struct with __refdata to prevent section mismatch
As described in the added code comment, a reference to .exit.text is ok
for drivers registered via module_platform_driver_probe(). Make this
explicit to prevent the following section mismatch warning

	WARNING: modpost: drivers/parport/parport_amiga: section mismatch in reference: amiga_parallel_driver+0x8 (section: .data) -> amiga_parallel_remove (section: .exit.text)

that triggers on an allmodconfig W=1 build.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20240513075206.2337310-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-04 18:08:31 +02:00

251 lines
6.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/* Low-level parallel port routines for the Amiga built-in port
*
* Author: Joerg Dorchain <joerg@dorchain.net>
*
* This is a complete rewrite of the code, but based heaviy upon the old
* lp_intern. code.
*
* The built-in Amiga parallel port provides one port at a fixed address
* with 8 bidirectional data lines (D0 - D7) and 3 bidirectional status
* lines (BUSY, POUT, SEL), 1 output control line /STROBE (raised automatically
* in hardware when the data register is accessed), and 1 input control line
* /ACK, able to cause an interrupt, but both not directly settable by
* software.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/parport.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <asm/setup.h>
#include <asm/amigahw.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/amigaints.h>
#undef DEBUG
static void amiga_write_data(struct parport *p, unsigned char data)
{
pr_debug("write_data %c\n", data);
/* Triggers also /STROBE. This behavior cannot be changed */
ciaa.prb = data;
mb();
}
static unsigned char amiga_read_data(struct parport *p)
{
/* Triggers also /STROBE. This behavior cannot be changed */
return ciaa.prb;
}
static unsigned char control_amiga_to_pc(unsigned char control)
{
return PARPORT_CONTROL_SELECT |
PARPORT_CONTROL_AUTOFD | PARPORT_CONTROL_STROBE;
/* fake value: interrupt enable, select in, no reset,
no autolf, no strobe - seems to be closest the wiring diagram */
}
static void amiga_write_control(struct parport *p, unsigned char control)
{
pr_debug("write_control %02x\n", control);
/* No implementation possible */
}
static unsigned char amiga_read_control( struct parport *p)
{
pr_debug("read_control\n");
return control_amiga_to_pc(0);
}
static unsigned char amiga_frob_control( struct parport *p, unsigned char mask, unsigned char val)
{
unsigned char old;
pr_debug("frob_control mask %02x, value %02x\n", mask, val);
old = amiga_read_control(p);
amiga_write_control(p, (old & ~mask) ^ val);
return old;
}
static unsigned char status_amiga_to_pc(unsigned char status)
{
unsigned char ret = PARPORT_STATUS_BUSY | PARPORT_STATUS_ACK | PARPORT_STATUS_ERROR;
if (status & 1) /* Busy */
ret &= ~PARPORT_STATUS_BUSY;
if (status & 2) /* PaperOut */
ret |= PARPORT_STATUS_PAPEROUT;
if (status & 4) /* Selected */
ret |= PARPORT_STATUS_SELECT;
/* the rest is not connected or handled autonomously in hardware */
return ret;
}
static unsigned char amiga_read_status(struct parport *p)
{
unsigned char status;
status = status_amiga_to_pc(ciab.pra & 7);
pr_debug("read_status %02x\n", status);
return status;
}
static void amiga_enable_irq(struct parport *p)
{
enable_irq(IRQ_AMIGA_CIAA_FLG);
}
static void amiga_disable_irq(struct parport *p)
{
disable_irq(IRQ_AMIGA_CIAA_FLG);
}
static void amiga_data_forward(struct parport *p)
{
pr_debug("forward\n");
ciaa.ddrb = 0xff; /* all pins output */
mb();
}
static void amiga_data_reverse(struct parport *p)
{
pr_debug("reverse\n");
ciaa.ddrb = 0; /* all pins input */
mb();
}
static void amiga_init_state(struct pardevice *dev, struct parport_state *s)
{
s->u.amiga.data = 0;
s->u.amiga.datadir = 255;
s->u.amiga.status = 0;
s->u.amiga.statusdir = 0;
}
static void amiga_save_state(struct parport *p, struct parport_state *s)
{
mb();
s->u.amiga.data = ciaa.prb;
s->u.amiga.datadir = ciaa.ddrb;
s->u.amiga.status = ciab.pra & 7;
s->u.amiga.statusdir = ciab.ddra & 7;
mb();
}
static void amiga_restore_state(struct parport *p, struct parport_state *s)
{
mb();
ciaa.prb = s->u.amiga.data;
ciaa.ddrb = s->u.amiga.datadir;
ciab.pra |= (ciab.pra & 0xf8) | s->u.amiga.status;
ciab.ddra |= (ciab.ddra & 0xf8) | s->u.amiga.statusdir;
mb();
}
static struct parport_operations pp_amiga_ops = {
.write_data = amiga_write_data,
.read_data = amiga_read_data,
.write_control = amiga_write_control,
.read_control = amiga_read_control,
.frob_control = amiga_frob_control,
.read_status = amiga_read_status,
.enable_irq = amiga_enable_irq,
.disable_irq = amiga_disable_irq,
.data_forward = amiga_data_forward,
.data_reverse = amiga_data_reverse,
.init_state = amiga_init_state,
.save_state = amiga_save_state,
.restore_state = amiga_restore_state,
.epp_write_data = parport_ieee1284_epp_write_data,
.epp_read_data = parport_ieee1284_epp_read_data,
.epp_write_addr = parport_ieee1284_epp_write_addr,
.epp_read_addr = parport_ieee1284_epp_read_addr,
.ecp_write_data = parport_ieee1284_ecp_write_data,
.ecp_read_data = parport_ieee1284_ecp_read_data,
.ecp_write_addr = parport_ieee1284_ecp_write_addr,
.compat_write_data = parport_ieee1284_write_compat,
.nibble_read_data = parport_ieee1284_read_nibble,
.byte_read_data = parport_ieee1284_read_byte,
.owner = THIS_MODULE,
};
/* ----------- Initialisation code --------------------------------- */
static int __init amiga_parallel_probe(struct platform_device *pdev)
{
struct parport *p;
int err;
ciaa.ddrb = 0xff;
ciab.ddra &= 0xf8;
mb();
p = parport_register_port((unsigned long)&ciaa.prb, IRQ_AMIGA_CIAA_FLG,
PARPORT_DMA_NONE, &pp_amiga_ops);
if (!p)
return -EBUSY;
err = request_irq(IRQ_AMIGA_CIAA_FLG, parport_irq_handler, 0, p->name,
p);
if (err)
goto out_irq;
pr_info("%s: Amiga built-in port using irq\n", p->name);
/* XXX: set operating mode */
parport_announce_port(p);
platform_set_drvdata(pdev, p);
return 0;
out_irq:
parport_put_port(p);
return err;
}
static void __exit amiga_parallel_remove(struct platform_device *pdev)
{
struct parport *port = platform_get_drvdata(pdev);
parport_remove_port(port);
if (port->irq != PARPORT_IRQ_NONE)
free_irq(IRQ_AMIGA_CIAA_FLG, port);
parport_put_port(port);
}
/*
* amiga_parallel_remove() lives in .exit.text. For drivers registered via
* module_platform_driver_probe() this is ok because they cannot get unbound at
* runtime. So mark the driver struct with __refdata to prevent modpost
* triggering a section mismatch warning.
*/
static struct platform_driver amiga_parallel_driver __refdata = {
.remove_new = __exit_p(amiga_parallel_remove),
.driver = {
.name = "amiga-parallel",
},
};
module_platform_driver_probe(amiga_parallel_driver, amiga_parallel_probe);
MODULE_AUTHOR("Joerg Dorchain <joerg@dorchain.net>");
MODULE_DESCRIPTION("Parport Driver for Amiga builtin Port");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:amiga-parallel");