xref: /openbmc/linux/drivers/ata/pata_cmd640.c (revision dfd4f649)
1 /*
2  * pata_cmd640.c 	- CMD640 PCI PATA for new ATA layer
3  *			  (C) 2007 Red Hat Inc
4  *
5  * Based upon
6  *  linux/drivers/ide/pci/cmd640.c		Version 1.02  Sep 01, 1996
7  *
8  *  Copyright (C) 1995-1996  Linus Torvalds & authors (see driver)
9  *
10  *	This drives only the PCI version of the controller. If you have a
11  *	VLB one then we have enough docs to support it but you can write
12  *	your own code.
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/pci.h>
18 #include <linux/blkdev.h>
19 #include <linux/delay.h>
20 #include <linux/gfp.h>
21 #include <scsi/scsi_host.h>
22 #include <linux/libata.h>
23 
24 #define DRV_NAME "pata_cmd640"
25 #define DRV_VERSION "0.0.5"
26 
27 struct cmd640_reg {
28 	int last;
29 	u8 reg58[ATA_MAX_DEVICES];
30 };
31 
32 enum {
33 	CFR = 0x50,
34 	CNTRL = 0x51,
35 	CMDTIM = 0x52,
36 	ARTIM0 = 0x53,
37 	DRWTIM0 = 0x54,
38 	ARTIM23 = 0x57,
39 	DRWTIM23 = 0x58,
40 	BRST = 0x59
41 };
42 
43 /**
44  *	cmd640_set_piomode	-	set initial PIO mode data
45  *	@ap: ATA port
46  *	@adev: ATA device
47  *
48  *	Called to do the PIO mode setup.
49  */
50 
51 static void cmd640_set_piomode(struct ata_port *ap, struct ata_device *adev)
52 {
53 	struct cmd640_reg *timing = ap->private_data;
54 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
55 	struct ata_timing t;
56 	const unsigned long T = 1000000 / 33;
57 	const u8 setup_data[] = { 0x40, 0x40, 0x40, 0x80, 0x00 };
58 	u8 reg;
59 	int arttim = ARTIM0 + 2 * adev->devno;
60 	struct ata_device *pair = ata_dev_pair(adev);
61 
62 	if (ata_timing_compute(adev, adev->pio_mode, &t, T, 0) < 0) {
63 		printk(KERN_ERR DRV_NAME ": mode computation failed.\n");
64 		return;
65 	}
66 
67 	/* The second channel has shared timings and the setup timing is
68 	   messy to switch to merge it for worst case */
69 	if (ap->port_no && pair) {
70 		struct ata_timing p;
71 		ata_timing_compute(pair, pair->pio_mode, &p, T, 1);
72 		ata_timing_merge(&p, &t, &t, ATA_TIMING_SETUP);
73 	}
74 
75 	/* Make the timings fit */
76 	if (t.recover > 16) {
77 		t.active += t.recover - 16;
78 		t.recover = 16;
79 	}
80 	if (t.active > 16)
81 		t.active = 16;
82 
83 	/* Now convert the clocks into values we can actually stuff into
84 	   the chip */
85 
86 	if (t.recover > 1)
87 		t.recover--;	/* 640B only */
88 	else
89 		t.recover = 15;
90 
91 	if (t.setup > 4)
92 		t.setup = 0xC0;
93 	else
94 		t.setup = setup_data[t.setup];
95 
96 	if (ap->port_no == 0) {
97 		t.active &= 0x0F;	/* 0 = 16 */
98 
99 		/* Load setup timing */
100 		pci_read_config_byte(pdev, arttim, &reg);
101 		reg &= 0x3F;
102 		reg |= t.setup;
103 		pci_write_config_byte(pdev, arttim, reg);
104 
105 		/* Load active/recovery */
106 		pci_write_config_byte(pdev, arttim + 1, (t.active << 4) | t.recover);
107 	} else {
108 		/* Save the shared timings for channel, they will be loaded
109 		   by qc_issue. Reloading the setup time is expensive so we
110 		   keep a merged one loaded */
111 		pci_read_config_byte(pdev, ARTIM23, &reg);
112 		reg &= 0x3F;
113 		reg |= t.setup;
114 		pci_write_config_byte(pdev, ARTIM23, reg);
115 		timing->reg58[adev->devno] = (t.active << 4) | t.recover;
116 	}
117 }
118 
119 
120 /**
121  *	cmd640_qc_issue	-	command preparation hook
122  *	@qc: Command to be issued
123  *
124  *	Channel 1 has shared timings. We must reprogram the
125  *	clock each drive 2/3 switch we do.
126  */
127 
128 static unsigned int cmd640_qc_issue(struct ata_queued_cmd *qc)
129 {
130 	struct ata_port *ap = qc->ap;
131 	struct ata_device *adev = qc->dev;
132 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
133 	struct cmd640_reg *timing = ap->private_data;
134 
135 	if (ap->port_no != 0 && adev->devno != timing->last) {
136 		pci_write_config_byte(pdev, DRWTIM23, timing->reg58[adev->devno]);
137 		timing->last = adev->devno;
138 	}
139 	return ata_sff_qc_issue(qc);
140 }
141 
142 /**
143  *	cmd640_port_start	-	port setup
144  *	@ap: ATA port being set up
145  *
146  *	The CMD640 needs to maintain private data structures so we
147  *	allocate space here.
148  */
149 
150 static int cmd640_port_start(struct ata_port *ap)
151 {
152 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
153 	struct cmd640_reg *timing;
154 
155 	timing = devm_kzalloc(&pdev->dev, sizeof(struct cmd640_reg), GFP_KERNEL);
156 	if (timing == NULL)
157 		return -ENOMEM;
158 	timing->last = -1;	/* Force a load */
159 	ap->private_data = timing;
160 	return 0;
161 }
162 
163 static bool cmd640_sff_irq_check(struct ata_port *ap)
164 {
165 	struct pci_dev *pdev	= to_pci_dev(ap->host->dev);
166 	int irq_reg		= ap->port_no ? ARTIM23 : CFR;
167 	u8  irq_stat, irq_mask	= ap->port_no ? 0x10 : 0x04;
168 
169 	pci_read_config_byte(pdev, irq_reg, &irq_stat);
170 
171 	return irq_stat & irq_mask;
172 }
173 
174 static struct scsi_host_template cmd640_sht = {
175 	ATA_PIO_SHT(DRV_NAME),
176 };
177 
178 static struct ata_port_operations cmd640_port_ops = {
179 	.inherits	= &ata_sff_port_ops,
180 	/* In theory xfer_noirq is not needed once we kill the prefetcher */
181 	.sff_data_xfer	= ata_sff_data_xfer32,
182 	.sff_irq_check	= cmd640_sff_irq_check,
183 	.qc_issue	= cmd640_qc_issue,
184 	.cable_detect	= ata_cable_40wire,
185 	.set_piomode	= cmd640_set_piomode,
186 	.port_start	= cmd640_port_start,
187 };
188 
189 static void cmd640_hardware_init(struct pci_dev *pdev)
190 {
191 	u8 ctrl;
192 
193 	/* CMD640 detected, commiserations */
194 	pci_write_config_byte(pdev, 0x5B, 0x00);
195 	/* PIO0 command cycles */
196 	pci_write_config_byte(pdev, CMDTIM, 0);
197 	/* 512 byte bursts (sector) */
198 	pci_write_config_byte(pdev, BRST, 0x40);
199 	/*
200 	 * A reporter a long time ago
201 	 * Had problems with the data fifo
202 	 * So don't run the risk
203 	 * Of putting crap on the disk
204 	 * For its better just to go slow
205 	 */
206 	/* Do channel 0 */
207 	pci_read_config_byte(pdev, CNTRL, &ctrl);
208 	pci_write_config_byte(pdev, CNTRL, ctrl | 0xC0);
209 	/* Ditto for channel 1 */
210 	pci_read_config_byte(pdev, ARTIM23, &ctrl);
211 	ctrl |= 0x0C;
212 	pci_write_config_byte(pdev, ARTIM23, ctrl);
213 }
214 
215 static int cmd640_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
216 {
217 	static const struct ata_port_info info = {
218 		.flags = ATA_FLAG_SLAVE_POSS,
219 		.pio_mask = ATA_PIO4,
220 		.port_ops = &cmd640_port_ops
221 	};
222 	const struct ata_port_info *ppi[] = { &info, NULL };
223 	int rc;
224 
225 	rc = pcim_enable_device(pdev);
226 	if (rc)
227 		return rc;
228 
229 	cmd640_hardware_init(pdev);
230 
231 	return ata_pci_sff_init_one(pdev, ppi, &cmd640_sht, NULL, 0);
232 }
233 
234 #ifdef CONFIG_PM_SLEEP
235 static int cmd640_reinit_one(struct pci_dev *pdev)
236 {
237 	struct ata_host *host = pci_get_drvdata(pdev);
238 	int rc;
239 
240 	rc = ata_pci_device_do_resume(pdev);
241 	if (rc)
242 		return rc;
243 	cmd640_hardware_init(pdev);
244 	ata_host_resume(host);
245 	return 0;
246 }
247 #endif
248 
249 static const struct pci_device_id cmd640[] = {
250 	{ PCI_VDEVICE(CMD, 0x640), 0 },
251 	{ },
252 };
253 
254 static struct pci_driver cmd640_pci_driver = {
255 	.name 		= DRV_NAME,
256 	.id_table	= cmd640,
257 	.probe 		= cmd640_init_one,
258 	.remove		= ata_pci_remove_one,
259 #ifdef CONFIG_PM_SLEEP
260 	.suspend	= ata_pci_device_suspend,
261 	.resume		= cmd640_reinit_one,
262 #endif
263 };
264 
265 module_pci_driver(cmd640_pci_driver);
266 
267 MODULE_AUTHOR("Alan Cox");
268 MODULE_DESCRIPTION("low-level driver for CMD640 PATA controllers");
269 MODULE_LICENSE("GPL");
270 MODULE_DEVICE_TABLE(pci, cmd640);
271 MODULE_VERSION(DRV_VERSION);
272