1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/types.h>
3 #include <linux/string.h>
4 #include <linux/kernel.h>
5 #include <linux/export.h>
6 #include <linux/interrupt.h>
7 #include <linux/ide.h>
8 #include <linux/bitops.h>
9 
10 static const char *udma_str[] =
11 	 { "UDMA/16", "UDMA/25",  "UDMA/33",  "UDMA/44",
12 	   "UDMA/66", "UDMA/100", "UDMA/133", "UDMA7" };
13 static const char *mwdma_str[] =
14 	{ "MWDMA0", "MWDMA1", "MWDMA2", "MWDMA3", "MWDMA4" };
15 static const char *swdma_str[] =
16 	{ "SWDMA0", "SWDMA1", "SWDMA2" };
17 static const char *pio_str[] =
18 	{ "PIO0", "PIO1", "PIO2", "PIO3", "PIO4", "PIO5", "PIO6" };
19 
20 /**
21  *	ide_xfer_verbose	-	return IDE mode names
22  *	@mode: transfer mode
23  *
24  *	Returns a constant string giving the name of the mode
25  *	requested.
26  */
27 
ide_xfer_verbose(u8 mode)28 const char *ide_xfer_verbose(u8 mode)
29 {
30 	const char *s;
31 	u8 i = mode & 0xf;
32 
33 	if (mode >= XFER_UDMA_0 && mode <= XFER_UDMA_7)
34 		s = udma_str[i];
35 	else if (mode >= XFER_MW_DMA_0 && mode <= XFER_MW_DMA_4)
36 		s = mwdma_str[i];
37 	else if (mode >= XFER_SW_DMA_0 && mode <= XFER_SW_DMA_2)
38 		s = swdma_str[i];
39 	else if (mode >= XFER_PIO_0 && mode <= XFER_PIO_6)
40 		s = pio_str[i & 0x7];
41 	else if (mode == XFER_PIO_SLOW)
42 		s = "PIO SLOW";
43 	else
44 		s = "XFER ERROR";
45 
46 	return s;
47 }
48 EXPORT_SYMBOL(ide_xfer_verbose);
49 
50 /**
51  *	ide_get_best_pio_mode	-	get PIO mode from drive
52  *	@drive: drive to consider
53  *	@mode_wanted: preferred mode
54  *	@max_mode: highest allowed mode
55  *
56  *	This routine returns the recommended PIO settings for a given drive,
57  *	based on the drive->id information and the ide_pio_blacklist[].
58  *
59  *	Drive PIO mode is auto-selected if 255 is passed as mode_wanted.
60  *	This is used by most chipset support modules when "auto-tuning".
61  */
62 
ide_get_best_pio_mode(ide_drive_t * drive,u8 mode_wanted,u8 max_mode)63 static u8 ide_get_best_pio_mode(ide_drive_t *drive, u8 mode_wanted, u8 max_mode)
64 {
65 	u16 *id = drive->id;
66 	int pio_mode = -1, overridden = 0;
67 
68 	if (mode_wanted != 255)
69 		return min_t(u8, mode_wanted, max_mode);
70 
71 	if ((drive->hwif->host_flags & IDE_HFLAG_PIO_NO_BLACKLIST) == 0)
72 		pio_mode = ide_scan_pio_blacklist((char *)&id[ATA_ID_PROD]);
73 
74 	if (pio_mode != -1) {
75 		printk(KERN_INFO "%s: is on PIO blacklist\n", drive->name);
76 	} else {
77 		pio_mode = id[ATA_ID_OLD_PIO_MODES] >> 8;
78 		if (pio_mode > 2) {	/* 2 is maximum allowed tPIO value */
79 			pio_mode = 2;
80 			overridden = 1;
81 		}
82 
83 		if (id[ATA_ID_FIELD_VALID] & 2) {	      /* ATA2? */
84 			if (ata_id_is_cfa(id) && (id[ATA_ID_CFA_MODES] & 7))
85 				pio_mode = 4 + min_t(int, 2,
86 						     id[ATA_ID_CFA_MODES] & 7);
87 			else if (ata_id_has_iordy(id)) {
88 				if (id[ATA_ID_PIO_MODES] & 7) {
89 					overridden = 0;
90 					if (id[ATA_ID_PIO_MODES] & 4)
91 						pio_mode = 5;
92 					else if (id[ATA_ID_PIO_MODES] & 2)
93 						pio_mode = 4;
94 					else
95 						pio_mode = 3;
96 				}
97 			}
98 		}
99 
100 		if (overridden)
101 			printk(KERN_INFO "%s: tPIO > 2, assuming tPIO = 2\n",
102 					 drive->name);
103 	}
104 
105 	if (pio_mode > max_mode)
106 		pio_mode = max_mode;
107 
108 	return pio_mode;
109 }
110 
ide_pio_need_iordy(ide_drive_t * drive,const u8 pio)111 int ide_pio_need_iordy(ide_drive_t *drive, const u8 pio)
112 {
113 	/*
114 	 * IORDY may lead to controller lock up on certain controllers
115 	 * if the port is not occupied.
116 	 */
117 	if (pio == 0 && (drive->hwif->port_flags & IDE_PFLAG_PROBING))
118 		return 0;
119 	return ata_id_pio_need_iordy(drive->id, pio);
120 }
121 EXPORT_SYMBOL_GPL(ide_pio_need_iordy);
122 
ide_set_pio_mode(ide_drive_t * drive,const u8 mode)123 int ide_set_pio_mode(ide_drive_t *drive, const u8 mode)
124 {
125 	ide_hwif_t *hwif = drive->hwif;
126 	const struct ide_port_ops *port_ops = hwif->port_ops;
127 
128 	if (hwif->host_flags & IDE_HFLAG_NO_SET_MODE)
129 		return 0;
130 
131 	if (port_ops == NULL || port_ops->set_pio_mode == NULL)
132 		return -1;
133 
134 	/*
135 	 * TODO: temporary hack for some legacy host drivers that didn't
136 	 * set transfer mode on the device in ->set_pio_mode method...
137 	 */
138 	if (port_ops->set_dma_mode == NULL) {
139 		drive->pio_mode = mode;
140 		port_ops->set_pio_mode(hwif, drive);
141 		return 0;
142 	}
143 
144 	if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
145 		if (ide_config_drive_speed(drive, mode))
146 			return -1;
147 		drive->pio_mode = mode;
148 		port_ops->set_pio_mode(hwif, drive);
149 		return 0;
150 	} else {
151 		drive->pio_mode = mode;
152 		port_ops->set_pio_mode(hwif, drive);
153 		return ide_config_drive_speed(drive, mode);
154 	}
155 }
156 
ide_set_dma_mode(ide_drive_t * drive,const u8 mode)157 int ide_set_dma_mode(ide_drive_t *drive, const u8 mode)
158 {
159 	ide_hwif_t *hwif = drive->hwif;
160 	const struct ide_port_ops *port_ops = hwif->port_ops;
161 
162 	if (hwif->host_flags & IDE_HFLAG_NO_SET_MODE)
163 		return 0;
164 
165 	if (port_ops == NULL || port_ops->set_dma_mode == NULL)
166 		return -1;
167 
168 	if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
169 		if (ide_config_drive_speed(drive, mode))
170 			return -1;
171 		drive->dma_mode = mode;
172 		port_ops->set_dma_mode(hwif, drive);
173 		return 0;
174 	} else {
175 		drive->dma_mode = mode;
176 		port_ops->set_dma_mode(hwif, drive);
177 		return ide_config_drive_speed(drive, mode);
178 	}
179 }
180 EXPORT_SYMBOL_GPL(ide_set_dma_mode);
181 
182 /* req_pio == "255" for auto-tune */
ide_set_pio(ide_drive_t * drive,u8 req_pio)183 void ide_set_pio(ide_drive_t *drive, u8 req_pio)
184 {
185 	ide_hwif_t *hwif = drive->hwif;
186 	const struct ide_port_ops *port_ops = hwif->port_ops;
187 	u8 host_pio, pio;
188 
189 	if (port_ops == NULL || port_ops->set_pio_mode == NULL ||
190 	    (hwif->host_flags & IDE_HFLAG_NO_SET_MODE))
191 		return;
192 
193 	BUG_ON(hwif->pio_mask == 0x00);
194 
195 	host_pio = fls(hwif->pio_mask) - 1;
196 
197 	pio = ide_get_best_pio_mode(drive, req_pio, host_pio);
198 
199 	/*
200 	 * TODO:
201 	 * - report device max PIO mode
202 	 * - check req_pio != 255 against device max PIO mode
203 	 */
204 	printk(KERN_DEBUG "%s: host max PIO%d wanted PIO%d%s selected PIO%d\n",
205 			  drive->name, host_pio, req_pio,
206 			  req_pio == 255 ? "(auto-tune)" : "", pio);
207 
208 	(void)ide_set_pio_mode(drive, XFER_PIO_0 + pio);
209 }
210 EXPORT_SYMBOL_GPL(ide_set_pio);
211 
212 /**
213  *	ide_rate_filter		-	filter transfer mode
214  *	@drive: IDE device
215  *	@speed: desired speed
216  *
217  *	Given the available transfer modes this function returns
218  *	the best available speed at or below the speed requested.
219  *
220  *	TODO: check device PIO capabilities
221  */
222 
ide_rate_filter(ide_drive_t * drive,u8 speed)223 static u8 ide_rate_filter(ide_drive_t *drive, u8 speed)
224 {
225 	ide_hwif_t *hwif = drive->hwif;
226 	u8 mode = ide_find_dma_mode(drive, speed);
227 
228 	if (mode == 0) {
229 		if (hwif->pio_mask)
230 			mode = fls(hwif->pio_mask) - 1 + XFER_PIO_0;
231 		else
232 			mode = XFER_PIO_4;
233 	}
234 
235 /*	printk("%s: mode 0x%02x, speed 0x%02x\n", __func__, mode, speed); */
236 
237 	return min(speed, mode);
238 }
239 
240 /**
241  *	ide_set_xfer_rate	-	set transfer rate
242  *	@drive: drive to set
243  *	@rate: speed to attempt to set
244  *
245  *	General helper for setting the speed of an IDE device. This
246  *	function knows about user enforced limits from the configuration
247  *	which ->set_pio_mode/->set_dma_mode does not.
248  */
249 
ide_set_xfer_rate(ide_drive_t * drive,u8 rate)250 int ide_set_xfer_rate(ide_drive_t *drive, u8 rate)
251 {
252 	ide_hwif_t *hwif = drive->hwif;
253 	const struct ide_port_ops *port_ops = hwif->port_ops;
254 
255 	if (port_ops == NULL || port_ops->set_dma_mode == NULL ||
256 	    (hwif->host_flags & IDE_HFLAG_NO_SET_MODE))
257 		return -1;
258 
259 	rate = ide_rate_filter(drive, rate);
260 
261 	BUG_ON(rate < XFER_PIO_0);
262 
263 	if (rate >= XFER_PIO_0 && rate <= XFER_PIO_6)
264 		return ide_set_pio_mode(drive, rate);
265 
266 	return ide_set_dma_mode(drive, rate);
267 }
268