xref: /openbmc/linux/drivers/ata/pata_cmd640.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * pata_cmd640.c 	- CMD640 PCI PATA for new ATA layer
4  *			  (C) 2007 Red Hat Inc
5  *
6  * Based upon
7  *  linux/drivers/ide/pci/cmd640.c		Version 1.02  Sep 01, 1996
8  *
9  *  Copyright (C) 1995-1996  Linus Torvalds & authors (see driver)
10  *
11  *	This drives only the PCI version of the controller. If you have a
12  *	VLB one then we have enough docs to support it but you can write
13  *	your own code.
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/pci.h>
19 #include <linux/blkdev.h>
20 #include <linux/delay.h>
21 #include <linux/gfp.h>
22 #include <scsi/scsi_host.h>
23 #include <linux/libata.h>
24 
25 #define DRV_NAME "pata_cmd640"
26 #define DRV_VERSION "0.0.5"
27 
28 struct cmd640_reg {
29 	int last;
30 	u8 reg58[ATA_MAX_DEVICES];
31 };
32 
33 enum {
34 	CFR = 0x50,
35 	CNTRL = 0x51,
36 	CMDTIM = 0x52,
37 	ARTIM0 = 0x53,
38 	DRWTIM0 = 0x54,
39 	ARTIM23 = 0x57,
40 	DRWTIM23 = 0x58,
41 	BRST = 0x59
42 };
43 
44 /**
45  *	cmd640_set_piomode	-	set initial PIO mode data
46  *	@ap: ATA port
47  *	@adev: ATA device
48  *
49  *	Called to do the PIO mode setup.
50  */
51 
52 static void cmd640_set_piomode(struct ata_port *ap, struct ata_device *adev)
53 {
54 	struct cmd640_reg *timing = ap->private_data;
55 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
56 	struct ata_timing t;
57 	const unsigned long T = 1000000 / 33;
58 	const u8 setup_data[] = { 0x40, 0x40, 0x40, 0x80, 0x00 };
59 	u8 reg;
60 	int arttim = ARTIM0 + 2 * adev->devno;
61 	struct ata_device *pair = ata_dev_pair(adev);
62 
63 	if (ata_timing_compute(adev, adev->pio_mode, &t, T, 0) < 0) {
64 		ata_dev_err(adev, DRV_NAME ": mode computation failed.\n");
65 		return;
66 	}
67 
68 	/* The second channel has shared timings and the setup timing is
69 	   messy to switch to merge it for worst case */
70 	if (ap->port_no && pair) {
71 		struct ata_timing p;
72 		ata_timing_compute(pair, pair->pio_mode, &p, T, 1);
73 		ata_timing_merge(&p, &t, &t, ATA_TIMING_SETUP);
74 	}
75 
76 	/* Make the timings fit */
77 	if (t.recover > 16) {
78 		t.active += t.recover - 16;
79 		t.recover = 16;
80 	}
81 	if (t.active > 16)
82 		t.active = 16;
83 
84 	/* Now convert the clocks into values we can actually stuff into
85 	   the chip */
86 
87 	if (t.recover > 1)
88 		t.recover--;	/* 640B only */
89 	else
90 		t.recover = 15;
91 
92 	if (t.setup > 4)
93 		t.setup = 0xC0;
94 	else
95 		t.setup = setup_data[t.setup];
96 
97 	if (ap->port_no == 0) {
98 		t.active &= 0x0F;	/* 0 = 16 */
99 
100 		/* Load setup timing */
101 		pci_read_config_byte(pdev, arttim, &reg);
102 		reg &= 0x3F;
103 		reg |= t.setup;
104 		pci_write_config_byte(pdev, arttim, reg);
105 
106 		/* Load active/recovery */
107 		pci_write_config_byte(pdev, arttim + 1, (t.active << 4) | t.recover);
108 	} else {
109 		/* Save the shared timings for channel, they will be loaded
110 		   by qc_issue. Reloading the setup time is expensive so we
111 		   keep a merged one loaded */
112 		pci_read_config_byte(pdev, ARTIM23, &reg);
113 		reg &= 0x3F;
114 		reg |= t.setup;
115 		pci_write_config_byte(pdev, ARTIM23, reg);
116 		timing->reg58[adev->devno] = (t.active << 4) | t.recover;
117 	}
118 }
119 
120 
121 /**
122  *	cmd640_qc_issue	-	command preparation hook
123  *	@qc: Command to be issued
124  *
125  *	Channel 1 has shared timings. We must reprogram the
126  *	clock each drive 2/3 switch we do.
127  */
128 
129 static unsigned int cmd640_qc_issue(struct ata_queued_cmd *qc)
130 {
131 	struct ata_port *ap = qc->ap;
132 	struct ata_device *adev = qc->dev;
133 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
134 	struct cmd640_reg *timing = ap->private_data;
135 
136 	if (ap->port_no != 0 && adev->devno != timing->last) {
137 		pci_write_config_byte(pdev, DRWTIM23, timing->reg58[adev->devno]);
138 		timing->last = adev->devno;
139 	}
140 	return ata_sff_qc_issue(qc);
141 }
142 
143 /**
144  *	cmd640_port_start	-	port setup
145  *	@ap: ATA port being set up
146  *
147  *	The CMD640 needs to maintain private data structures so we
148  *	allocate space here.
149  */
150 
151 static int cmd640_port_start(struct ata_port *ap)
152 {
153 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
154 	struct cmd640_reg *timing;
155 
156 	timing = devm_kzalloc(&pdev->dev, sizeof(struct cmd640_reg), GFP_KERNEL);
157 	if (timing == NULL)
158 		return -ENOMEM;
159 	timing->last = -1;	/* Force a load */
160 	ap->private_data = timing;
161 	return 0;
162 }
163 
164 static bool cmd640_sff_irq_check(struct ata_port *ap)
165 {
166 	struct pci_dev *pdev	= to_pci_dev(ap->host->dev);
167 	int irq_reg		= ap->port_no ? ARTIM23 : CFR;
168 	u8  irq_stat, irq_mask	= ap->port_no ? 0x10 : 0x04;
169 
170 	pci_read_config_byte(pdev, irq_reg, &irq_stat);
171 
172 	return irq_stat & irq_mask;
173 }
174 
175 static struct scsi_host_template cmd640_sht = {
176 	ATA_PIO_SHT(DRV_NAME),
177 };
178 
179 static struct ata_port_operations cmd640_port_ops = {
180 	.inherits	= &ata_sff_port_ops,
181 	/* In theory xfer_noirq is not needed once we kill the prefetcher */
182 	.sff_data_xfer	= ata_sff_data_xfer32,
183 	.sff_irq_check	= cmd640_sff_irq_check,
184 	.qc_issue	= cmd640_qc_issue,
185 	.cable_detect	= ata_cable_40wire,
186 	.set_piomode	= cmd640_set_piomode,
187 	.port_start	= cmd640_port_start,
188 };
189 
190 static void cmd640_hardware_init(struct pci_dev *pdev)
191 {
192 	u8 ctrl;
193 
194 	/* CMD640 detected, commiserations */
195 	pci_write_config_byte(pdev, 0x5B, 0x00);
196 	/* PIO0 command cycles */
197 	pci_write_config_byte(pdev, CMDTIM, 0);
198 	/* 512 byte bursts (sector) */
199 	pci_write_config_byte(pdev, BRST, 0x40);
200 	/*
201 	 * A reporter a long time ago
202 	 * Had problems with the data fifo
203 	 * So don't run the risk
204 	 * Of putting crap on the disk
205 	 * For its better just to go slow
206 	 */
207 	/* Do channel 0 */
208 	pci_read_config_byte(pdev, CNTRL, &ctrl);
209 	pci_write_config_byte(pdev, CNTRL, ctrl | 0xC0);
210 	/* Ditto for channel 1 */
211 	pci_read_config_byte(pdev, ARTIM23, &ctrl);
212 	ctrl |= 0x0C;
213 	pci_write_config_byte(pdev, ARTIM23, ctrl);
214 }
215 
216 static int cmd640_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
217 {
218 	static const struct ata_port_info info = {
219 		.flags = ATA_FLAG_SLAVE_POSS,
220 		.pio_mask = ATA_PIO4,
221 		.port_ops = &cmd640_port_ops
222 	};
223 	const struct ata_port_info *ppi[] = { &info, NULL };
224 	int rc;
225 
226 	rc = pcim_enable_device(pdev);
227 	if (rc)
228 		return rc;
229 
230 	cmd640_hardware_init(pdev);
231 
232 	return ata_pci_sff_init_one(pdev, ppi, &cmd640_sht, NULL, 0);
233 }
234 
235 #ifdef CONFIG_PM_SLEEP
236 static int cmd640_reinit_one(struct pci_dev *pdev)
237 {
238 	struct ata_host *host = pci_get_drvdata(pdev);
239 	int rc;
240 
241 	rc = ata_pci_device_do_resume(pdev);
242 	if (rc)
243 		return rc;
244 	cmd640_hardware_init(pdev);
245 	ata_host_resume(host);
246 	return 0;
247 }
248 #endif
249 
250 static const struct pci_device_id cmd640[] = {
251 	{ PCI_VDEVICE(CMD, 0x640), 0 },
252 	{ },
253 };
254 
255 static struct pci_driver cmd640_pci_driver = {
256 	.name 		= DRV_NAME,
257 	.id_table	= cmd640,
258 	.probe 		= cmd640_init_one,
259 	.remove		= ata_pci_remove_one,
260 #ifdef CONFIG_PM_SLEEP
261 	.suspend	= ata_pci_device_suspend,
262 	.resume		= cmd640_reinit_one,
263 #endif
264 };
265 
266 module_pci_driver(cmd640_pci_driver);
267 
268 MODULE_AUTHOR("Alan Cox");
269 MODULE_DESCRIPTION("low-level driver for CMD640 PATA controllers");
270 MODULE_LICENSE("GPL");
271 MODULE_DEVICE_TABLE(pci, cmd640);
272 MODULE_VERSION(DRV_VERSION);
273