treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / ide / dtc2278.c
blob714e8cd0fa4918b0ccce5c5022cdf99454eb6db1
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 1996 Linus Torvalds & author (see below)
4 */
6 #include <linux/module.h>
7 #include <linux/types.h>
8 #include <linux/kernel.h>
9 #include <linux/delay.h>
10 #include <linux/timer.h>
11 #include <linux/mm.h>
12 #include <linux/ioport.h>
13 #include <linux/blkdev.h>
14 #include <linux/ide.h>
15 #include <linux/init.h>
17 #include <asm/io.h>
19 #define DRV_NAME "dtc2278"
22 * Changing this #undef to #define may solve start up problems in some systems.
24 #undef ALWAYS_SET_DTC2278_PIO_MODE
27 * From: andy@cercle.cts.com (Dyan Wile)
29 * Below is a patch for DTC-2278 - alike software-programmable controllers
30 * The code enables the secondary IDE controller and the PIO4 (3?) timings on
31 * the primary (EIDE). You may probably have to enable the 32-bit support to
32 * get the full speed. You better get the disk interrupts disabled ( hdparm -u0
33 * /dev/hd.. ) for the drives connected to the EIDE interface. (I get my
34 * filesystem corrupted with -u1, but under heavy disk load only :-)
36 * This card is now forced to use the "serialize" feature,
37 * and irq-unmasking is disallowed. If io_32bit is enabled,
38 * it must be done for BOTH drives on each interface.
40 * This code was written for the DTC2278E, but might work with any of these:
42 * DTC2278S has only a single IDE interface.
43 * DTC2278D has two IDE interfaces and is otherwise identical to the S version.
44 * DTC2278E also has serial ports and a printer port
45 * DTC2278EB: has onboard BIOS, and "works like a charm" -- Kent Bradford <kent@theory.caltech.edu>
47 * There may be a fourth controller type. The S and D versions use the
48 * Winbond chip, and I think the E version does also.
52 static void sub22 (char b, char c)
54 int i;
56 for(i = 0; i < 3; ++i) {
57 inb(0x3f6);
58 outb_p(b,0xb0);
59 inb(0x3f6);
60 outb_p(c,0xb4);
61 inb(0x3f6);
62 if(inb(0xb4) == c) {
63 outb_p(7,0xb0);
64 inb(0x3f6);
65 return; /* success */
70 static DEFINE_SPINLOCK(dtc2278_lock);
72 static void dtc2278_set_pio_mode(ide_hwif_t *hwif, ide_drive_t *drive)
74 unsigned long flags;
76 if (drive->pio_mode >= XFER_PIO_3) {
77 spin_lock_irqsave(&dtc2278_lock, flags);
79 * This enables PIO mode4 (3?) on the first interface
81 sub22(1,0xc3);
82 sub22(0,0xa0);
83 spin_unlock_irqrestore(&dtc2278_lock, flags);
84 } else {
85 /* we don't know how to set it back again.. */
86 /* Actually we do - there is a data sheet available for the
87 Winbond but does anyone actually care */
91 static const struct ide_port_ops dtc2278_port_ops = {
92 .set_pio_mode = dtc2278_set_pio_mode,
95 static const struct ide_port_info dtc2278_port_info __initconst = {
96 .name = DRV_NAME,
97 .chipset = ide_dtc2278,
98 .port_ops = &dtc2278_port_ops,
99 .host_flags = IDE_HFLAG_SERIALIZE |
100 IDE_HFLAG_NO_UNMASK_IRQS |
101 IDE_HFLAG_IO_32BIT |
102 /* disallow ->io_32bit changes */
103 IDE_HFLAG_NO_IO_32BIT |
104 IDE_HFLAG_NO_DMA |
105 IDE_HFLAG_DTC2278,
106 .pio_mask = ATA_PIO4,
109 static int __init dtc2278_probe(void)
111 unsigned long flags;
113 local_irq_save(flags);
115 * This enables the second interface
117 outb_p(4,0xb0);
118 inb(0x3f6);
119 outb_p(0x20,0xb4);
120 inb(0x3f6);
121 #ifdef ALWAYS_SET_DTC2278_PIO_MODE
123 * This enables PIO mode4 (3?) on the first interface
124 * and may solve start-up problems for some people.
126 sub22(1,0xc3);
127 sub22(0,0xa0);
128 #endif
129 local_irq_restore(flags);
131 return ide_legacy_device_add(&dtc2278_port_info, 0);
134 static bool probe_dtc2278;
136 module_param_named(probe, probe_dtc2278, bool, 0);
137 MODULE_PARM_DESC(probe, "probe for DTC2278xx chipsets");
139 static int __init dtc2278_init(void)
141 if (probe_dtc2278 == 0)
142 return -ENODEV;
144 if (dtc2278_probe()) {
145 printk(KERN_ERR "dtc2278: ide interfaces already in use!\n");
146 return -EBUSY;
148 return 0;
151 module_init(dtc2278_init);
153 MODULE_AUTHOR("See Local File");
154 MODULE_DESCRIPTION("support of DTC-2278 VLB IDE chipsets");
155 MODULE_LICENSE("GPL");