android_kernel_xiaomi_sm8350/drivers/serial/8250_hp300.c
Bjorn Helgaas e51c01b084 [PATCH] hp300: fix driver_register() return handling, remove dio_module_init()
Remove the assumption that driver_register() returns the number of devices
bound to the driver.  In fact, it returns zero for success or a negative
error value.

dio_module_init() used the device count to automatically unregister and
unload drivers that found no devices.  That might have worked at one time,
but has been broken for some time because dio_register_driver() returned
either a negative error or a positive count (never zero).  So it could only
unregister on failure, when it's not needed anyway.

This functionality could be resurrected in individual drivers by counting
devices in their .probe() methods.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Philip Blundell <philb@gnu.org>
Cc: Jochen Friedrich <jochen@scram.de>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 08:22:53 -08:00

331 lines
7.7 KiB
C

/*
* Driver for the 98626/98644/internal serial interface on hp300/hp400
* (based on the National Semiconductor INS8250/NS16550AF/WD16C552 UARTs)
*
* Ported from 2.2 and modified to use the normal 8250 driver
* by Kars de Jong <jongk@linux-m68k.org>, May 2004.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/delay.h>
#include <linux/dio.h>
#include <linux/console.h>
#include <asm/io.h>
#include "8250.h"
#if !defined(CONFIG_HPDCA) && !defined(CONFIG_HPAPCI)
#warning CONFIG_8250 defined but neither CONFIG_HPDCA nor CONFIG_HPAPCI defined, are you sure?
#endif
#ifdef CONFIG_HPAPCI
struct hp300_port
{
struct hp300_port *next; /* next port */
int line; /* line (tty) number */
};
static struct hp300_port *hp300_ports;
#endif
#ifdef CONFIG_HPDCA
static int __devinit hpdca_init_one(struct dio_dev *d,
const struct dio_device_id *ent);
static void __devexit hpdca_remove_one(struct dio_dev *d);
static struct dio_device_id hpdca_dio_tbl[] = {
{ DIO_ID_DCA0 },
{ DIO_ID_DCA0REM },
{ DIO_ID_DCA1 },
{ DIO_ID_DCA1REM },
{ 0 }
};
static struct dio_driver hpdca_driver = {
.name = "hpdca",
.id_table = hpdca_dio_tbl,
.probe = hpdca_init_one,
.remove = __devexit_p(hpdca_remove_one),
};
#endif
static unsigned int num_ports;
extern int hp300_uart_scode;
/* Offset to UART registers from base of DCA */
#define UART_OFFSET 17
#define DCA_ID 0x01 /* ID (read), reset (write) */
#define DCA_IC 0x03 /* Interrupt control */
/* Interrupt control */
#define DCA_IC_IE 0x80 /* Master interrupt enable */
#define HPDCA_BAUD_BASE 153600
/* Base address of the Frodo part */
#define FRODO_BASE (0x41c000)
/*
* Where we find the 8250-like APCI ports, and how far apart they are.
*/
#define FRODO_APCIBASE 0x0
#define FRODO_APCISPACE 0x20
#define FRODO_APCI_OFFSET(x) (FRODO_APCIBASE + ((x) * FRODO_APCISPACE))
#define HPAPCI_BAUD_BASE 500400
#ifdef CONFIG_SERIAL_8250_CONSOLE
/*
* Parse the bootinfo to find descriptions for headless console and
* debug serial ports and register them with the 8250 driver.
* This function should be called before serial_console_init() is called
* to make sure the serial console will be available for use. IA-64 kernel
* calls this function from setup_arch() after the EFI and ACPI tables have
* been parsed.
*/
int __init hp300_setup_serial_console(void)
{
int scode;
struct uart_port port;
memset(&port, 0, sizeof(port));
if (hp300_uart_scode < 0 || hp300_uart_scode > DIO_SCMAX)
return 0;
if (DIO_SCINHOLE(hp300_uart_scode))
return 0;
scode = hp300_uart_scode;
/* Memory mapped I/O */
port.iotype = UPIO_MEM;
port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF;
port.type = PORT_UNKNOWN;
/* Check for APCI console */
if (scode == 256) {
#ifdef CONFIG_HPAPCI
printk(KERN_INFO "Serial console is HP APCI 1\n");
port.uartclk = HPAPCI_BAUD_BASE * 16;
port.mapbase = (FRODO_BASE + FRODO_APCI_OFFSET(1));
port.membase = (char *)(port.mapbase + DIO_VIRADDRBASE);
port.regshift = 2;
add_preferred_console("ttyS", port.line, "9600n8");
#else
printk(KERN_WARNING "Serial console is APCI but support is disabled (CONFIG_HPAPCI)!\n");
return 0;
#endif
}
else {
#ifdef CONFIG_HPDCA
unsigned long pa = dio_scodetophysaddr(scode);
if (!pa) {
return 0;
}
printk(KERN_INFO "Serial console is HP DCA at select code %d\n", scode);
port.uartclk = HPDCA_BAUD_BASE * 16;
port.mapbase = (pa + UART_OFFSET);
port.membase = (char *)(port.mapbase + DIO_VIRADDRBASE);
port.regshift = 1;
port.irq = DIO_IPL(pa + DIO_VIRADDRBASE);
/* Enable board-interrupts */
out_8(pa + DIO_VIRADDRBASE + DCA_IC, DCA_IC_IE);
if (DIO_ID(pa + DIO_VIRADDRBASE) & 0x80) {
add_preferred_console("ttyS", port.line, "9600n8");
}
#else
printk(KERN_WARNING "Serial console is DCA but support is disabled (CONFIG_HPDCA)!\n");
return 0;
#endif
}
if (early_serial_setup(&port) < 0) {
printk(KERN_WARNING "hp300_setup_serial_console(): early_serial_setup() failed.\n");
}
return 0;
}
#endif /* CONFIG_SERIAL_8250_CONSOLE */
#ifdef CONFIG_HPDCA
static int __devinit hpdca_init_one(struct dio_dev *d,
const struct dio_device_id *ent)
{
struct uart_port port;
int line;
#ifdef CONFIG_SERIAL_8250_CONSOLE
if (hp300_uart_scode == d->scode) {
/* Already got it. */
return 0;
}
#endif
memset(&port, 0, sizeof(struct uart_port));
/* Memory mapped I/O */
port.iotype = UPIO_MEM;
port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF;
port.irq = d->ipl;
port.uartclk = HPDCA_BAUD_BASE * 16;
port.mapbase = (d->resource.start + UART_OFFSET);
port.membase = (char *)(port.mapbase + DIO_VIRADDRBASE);
port.regshift = 1;
port.dev = &d->dev;
line = serial8250_register_port(&port);
if (line < 0) {
printk(KERN_NOTICE "8250_hp300: register_serial() DCA scode %d"
" irq %d failed\n", d->scode, port.irq);
return -ENOMEM;
}
/* Enable board-interrupts */
out_8(d->resource.start + DIO_VIRADDRBASE + DCA_IC, DCA_IC_IE);
dio_set_drvdata(d, (void *)line);
/* Reset the DCA */
out_8(d->resource.start + DIO_VIRADDRBASE + DCA_ID, 0xff);
udelay(100);
num_ports++;
return 0;
}
#endif
static int __init hp300_8250_init(void)
{
static int called = 0;
#ifdef CONFIG_HPAPCI
int line;
unsigned long base;
struct uart_port uport;
struct hp300_port *port;
int i;
#endif
if (called)
return -ENODEV;
called = 1;
if (!MACH_IS_HP300)
return -ENODEV;
#ifdef CONFIG_HPDCA
dio_register_driver(&hpdca_driver);
#endif
#ifdef CONFIG_HPAPCI
if (hp300_model < HP_400) {
if (!num_ports)
return -ENODEV;
return 0;
}
/* These models have the Frodo chip.
* Port 0 is reserved for the Apollo Domain keyboard.
* Port 1 is either the console or the DCA.
*/
for (i = 1; i < 4; i++) {
/* Port 1 is the console on a 425e, on other machines it's mapped to
* DCA.
*/
#ifdef CONFIG_SERIAL_8250_CONSOLE
if (i == 1) {
continue;
}
#endif
/* Create new serial device */
port = kmalloc(sizeof(struct hp300_port), GFP_KERNEL);
if (!port)
return -ENOMEM;
memset(&uport, 0, sizeof(struct uart_port));
base = (FRODO_BASE + FRODO_APCI_OFFSET(i));
/* Memory mapped I/O */
uport.iotype = UPIO_MEM;
uport.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF;
/* XXX - no interrupt support yet */
uport.irq = 0;
uport.uartclk = HPAPCI_BAUD_BASE * 16;
uport.mapbase = base;
uport.membase = (char *)(base + DIO_VIRADDRBASE);
uport.regshift = 2;
line = serial8250_register_port(&uport);
if (line < 0) {
printk(KERN_NOTICE "8250_hp300: register_serial() APCI %d"
" irq %d failed\n", i, uport.irq);
kfree(port);
continue;
}
port->line = line;
port->next = hp300_ports;
hp300_ports = port;
num_ports++;
}
#endif
/* Any boards found? */
if (!num_ports)
return -ENODEV;
return 0;
}
#ifdef CONFIG_HPDCA
static void __devexit hpdca_remove_one(struct dio_dev *d)
{
int line;
line = (int) dio_get_drvdata(d);
if (d->resource.start) {
/* Disable board-interrupts */
out_8(d->resource.start + DIO_VIRADDRBASE + DCA_IC, 0);
}
serial8250_unregister_port(line);
}
#endif
static void __exit hp300_8250_exit(void)
{
#ifdef CONFIG_HPAPCI
struct hp300_port *port, *to_free;
for (port = hp300_ports; port; ) {
serial8250_unregister_port(port->line);
to_free = port;
port = port->next;
kfree(to_free);
}
hp300_ports = NULL;
#endif
#ifdef CONFIG_HPDCA
dio_unregister_driver(&hpdca_driver);
#endif
}
module_init(hp300_8250_init);
module_exit(hp300_8250_exit);
MODULE_DESCRIPTION("HP DCA/APCI serial driver");
MODULE_AUTHOR("Kars de Jong <jongk@linux-m68k.org>");
MODULE_LICENSE("GPL");