1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * New ATA layer SC1200 driver		Alan Cox <alan@lxorguk.ukuu.org.uk>
4  *
5  * TODO: Mode selection filtering
6  * TODO: Needs custom DMA cleanup code
7  *
8  * Based very heavily on
9  *
10  * linux/drivers/ide/pci/sc1200.c		Version 0.91	28-Jan-2003
11  *
12  * Copyright (C) 2000-2002		Mark Lord <mlord@pobox.com>
13  * May be copied or modified under the terms of the GNU General Public License
14  *
15  * Development of this chipset driver was funded
16  * by the nice folks at National Semiconductor.
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/pci.h>
22 #include <linux/blkdev.h>
23 #include <linux/delay.h>
24 #include <scsi/scsi_host.h>
25 #include <linux/libata.h>
26 
27 #define DRV_NAME	"pata_sc1200"
28 #define DRV_VERSION	"0.2.6"
29 
30 #define SC1200_REV_A	0x00
31 #define SC1200_REV_B1	0x01
32 #define SC1200_REV_B3	0x02
33 #define SC1200_REV_C1	0x03
34 #define SC1200_REV_D1	0x04
35 
36 /**
37  *	sc1200_clock	-	PCI clock
38  *
39  *	Return the PCI bus clocking for the SC1200 chipset configuration
40  *	in use. We return 0 for 33MHz 1 for 48MHz and 2 for 66Mhz
41  */
42 
sc1200_clock(void)43 static int sc1200_clock(void)
44 {
45 	/* Magic registers that give us the chipset data */
46 	u8 chip_id = inb(0x903C);
47 	u8 silicon_rev = inb(0x903D);
48 	u16 pci_clock;
49 
50 	if (chip_id == 0x04 && silicon_rev < SC1200_REV_B1)
51 		return 0;	/* 33 MHz mode */
52 
53 	/* Clock generator configuration 0x901E its 8/9 are the PCI clocking
54 	   0/3 is 33Mhz 1 is 48 2 is 66 */
55 
56 	pci_clock = inw(0x901E);
57 	pci_clock >>= 8;
58 	pci_clock &= 0x03;
59 	if (pci_clock == 3)
60 		pci_clock = 0;
61 	return pci_clock;
62 }
63 
64 /**
65  *	sc1200_set_piomode		-	PIO setup
66  *	@ap: ATA interface
67  *	@adev: device on the interface
68  *
69  *	Set our PIO requirements. This is fairly simple on the SC1200
70  */
71 
sc1200_set_piomode(struct ata_port * ap,struct ata_device * adev)72 static void sc1200_set_piomode(struct ata_port *ap, struct ata_device *adev)
73 {
74 	static const u32 pio_timings[4][5] = {
75 		/* format0, 33Mhz */
76 		{ 0x00009172, 0x00012171, 0x00020080, 0x00032010, 0x00040010 },
77 		/* format1, 33Mhz */
78 		{ 0xd1329172, 0x71212171, 0x30200080, 0x20102010, 0x00100010 },
79 		/* format1, 48Mhz */
80 		{ 0xfaa3f4f3, 0xc23232b2, 0x513101c1, 0x31213121, 0x10211021 },
81 		/* format1, 66Mhz */
82 		{ 0xfff4fff4, 0xf35353d3, 0x814102f1, 0x42314231, 0x11311131 }
83 	};
84 
85 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
86 	u32 format;
87 	unsigned int reg = 0x40 + 0x10 * ap->port_no;
88 	int mode = adev->pio_mode - XFER_PIO_0;
89 
90 	pci_read_config_dword(pdev, reg + 4, &format);
91 	format >>= 31;
92 	format += sc1200_clock();
93 	pci_write_config_dword(pdev, reg + 8 * adev->devno,
94 				pio_timings[format][mode]);
95 }
96 
97 /**
98  *	sc1200_set_dmamode		-	DMA timing setup
99  *	@ap: ATA interface
100  *	@adev: Device being configured
101  *
102  *	We cannot mix MWDMA and UDMA without reloading timings each switch
103  *	master to slave.
104  */
105 
sc1200_set_dmamode(struct ata_port * ap,struct ata_device * adev)106 static void sc1200_set_dmamode(struct ata_port *ap, struct ata_device *adev)
107 {
108 	static const u32 udma_timing[3][3] = {
109 		{ 0x00921250, 0x00911140, 0x00911030 },
110 		{ 0x00932470, 0x00922260, 0x00922140 },
111 		{ 0x009436A1, 0x00933481, 0x00923261 }
112 	};
113 
114 	static const u32 mwdma_timing[3][3] = {
115 		{ 0x00077771, 0x00012121, 0x00002020 },
116 		{ 0x000BBBB2, 0x00024241, 0x00013131 },
117 		{ 0x000FFFF3, 0x00035352, 0x00015151 }
118 	};
119 
120 	int clock = sc1200_clock();
121 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
122 	unsigned int reg = 0x40 + 0x10 * ap->port_no;
123 	int mode = adev->dma_mode;
124 	u32 format;
125 
126 	if (mode >= XFER_UDMA_0)
127 		format = udma_timing[clock][mode - XFER_UDMA_0];
128 	else
129 		format = mwdma_timing[clock][mode - XFER_MW_DMA_0];
130 
131 	if (adev->devno == 0) {
132 		u32 timings;
133 
134 		pci_read_config_dword(pdev, reg + 4, &timings);
135 		timings &= 0x80000000UL;
136 		timings |= format;
137 		pci_write_config_dword(pdev, reg + 4, timings);
138 	} else
139 		pci_write_config_dword(pdev, reg + 12, format);
140 }
141 
142 /**
143  *	sc1200_qc_issue		-	command issue
144  *	@qc: command pending
145  *
146  *	Called when the libata layer is about to issue a command. We wrap
147  *	this interface so that we can load the correct ATA timings if
148  *	necessary.  Specifically we have a problem that there is only
149  *	one MWDMA/UDMA bit.
150  */
151 
sc1200_qc_issue(struct ata_queued_cmd * qc)152 static unsigned int sc1200_qc_issue(struct ata_queued_cmd *qc)
153 {
154 	struct ata_port *ap = qc->ap;
155 	struct ata_device *adev = qc->dev;
156 	struct ata_device *prev = ap->private_data;
157 
158 	/* See if the DMA settings could be wrong */
159 	if (ata_dma_enabled(adev) && adev != prev && prev != NULL) {
160 		/* Maybe, but do the channels match MWDMA/UDMA ? */
161 		if ((ata_using_udma(adev) && !ata_using_udma(prev)) ||
162 		    (ata_using_udma(prev) && !ata_using_udma(adev)))
163 		    	/* Switch the mode bits */
164 		    	sc1200_set_dmamode(ap, adev);
165 	}
166 
167 	return ata_bmdma_qc_issue(qc);
168 }
169 
170 /**
171  *	sc1200_qc_defer	-	implement serialization
172  *	@qc: command
173  *
174  *	Serialize command issue on this controller.
175  */
176 
sc1200_qc_defer(struct ata_queued_cmd * qc)177 static int sc1200_qc_defer(struct ata_queued_cmd *qc)
178 {
179 	struct ata_host *host = qc->ap->host;
180 	struct ata_port *alt = host->ports[1 ^ qc->ap->port_no];
181 	int rc;
182 
183 	/* First apply the usual rules */
184 	rc = ata_std_qc_defer(qc);
185 	if (rc != 0)
186 		return rc;
187 
188 	/* Now apply serialization rules. Only allow a command if the
189 	   other channel state machine is idle */
190 	if (alt && alt->qc_active)
191 		return	ATA_DEFER_PORT;
192 	return 0;
193 }
194 
195 static struct scsi_host_template sc1200_sht = {
196 	ATA_BASE_SHT(DRV_NAME),
197 	.sg_tablesize	= LIBATA_DUMB_MAX_PRD,
198 	.dma_boundary	= ATA_DMA_BOUNDARY,
199 };
200 
201 static struct ata_port_operations sc1200_port_ops = {
202 	.inherits	= &ata_bmdma_port_ops,
203 	.qc_prep 	= ata_bmdma_dumb_qc_prep,
204 	.qc_issue	= sc1200_qc_issue,
205 	.qc_defer	= sc1200_qc_defer,
206 	.cable_detect	= ata_cable_40wire,
207 	.set_piomode	= sc1200_set_piomode,
208 	.set_dmamode	= sc1200_set_dmamode,
209 };
210 
211 /**
212  *	sc1200_init_one		-	Initialise an SC1200
213  *	@dev: PCI device
214  *	@id: Entry in match table
215  *
216  *	Just throw the needed data at the libata helper and it does all
217  *	our work.
218  */
219 
sc1200_init_one(struct pci_dev * dev,const struct pci_device_id * id)220 static int sc1200_init_one(struct pci_dev *dev, const struct pci_device_id *id)
221 {
222 	static const struct ata_port_info info = {
223 		.flags = ATA_FLAG_SLAVE_POSS,
224 		.pio_mask = ATA_PIO4,
225 		.mwdma_mask = ATA_MWDMA2,
226 		.udma_mask = ATA_UDMA2,
227 		.port_ops = &sc1200_port_ops
228 	};
229 	const struct ata_port_info *ppi[] = { &info, NULL };
230 
231 	return ata_pci_bmdma_init_one(dev, ppi, &sc1200_sht, NULL, 0);
232 }
233 
234 static const struct pci_device_id sc1200[] = {
235 	{ PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_SCx200_IDE), },
236 
237 	{ },
238 };
239 
240 static struct pci_driver sc1200_pci_driver = {
241 	.name 		= DRV_NAME,
242 	.id_table	= sc1200,
243 	.probe 		= sc1200_init_one,
244 	.remove		= ata_pci_remove_one,
245 #ifdef CONFIG_PM_SLEEP
246 	.suspend	= ata_pci_device_suspend,
247 	.resume		= ata_pci_device_resume,
248 #endif
249 };
250 
251 module_pci_driver(sc1200_pci_driver);
252 
253 MODULE_AUTHOR("Alan Cox, Mark Lord");
254 MODULE_DESCRIPTION("low-level driver for the NS/AMD SC1200");
255 MODULE_LICENSE("GPL");
256 MODULE_DEVICE_TABLE(pci, sc1200);
257 MODULE_VERSION(DRV_VERSION);
258