xref: /openbmc/linux/drivers/ata/pata_cs5536.c (revision afb46f79)
1 /*
2  * pata_cs5536.c	- CS5536 PATA for new ATA layer
3  *			  (C) 2007 Martin K. Petersen <mkp@mkp.net>
4  *			  (C) 2011 Bartlomiej Zolnierkiewicz
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307	 USA
18  *
19  * Documentation:
20  *	Available from AMD web site.
21  *
22  * The IDE timing registers for the CS5536 live in the Geode Machine
23  * Specific Register file and not PCI config space.  Most BIOSes
24  * virtualize the PCI registers so the chip looks like a standard IDE
25  * controller.	Unfortunately not all implementations get this right.
26  * In particular some have problems with unaligned accesses to the
27  * virtualized PCI registers.  This driver always does full dword
28  * writes to work around the issue.  Also, in case of a bad BIOS this
29  * driver can be loaded with the "msr=1" parameter which forces using
30  * the Machine Specific Registers to configure the device.
31  */
32 
33 #include <linux/kernel.h>
34 #include <linux/module.h>
35 #include <linux/pci.h>
36 #include <linux/blkdev.h>
37 #include <linux/delay.h>
38 #include <linux/libata.h>
39 #include <scsi/scsi_host.h>
40 #include <linux/dmi.h>
41 
42 #ifdef CONFIG_X86_32
43 #include <asm/msr.h>
44 static int use_msr;
45 module_param_named(msr, use_msr, int, 0644);
46 MODULE_PARM_DESC(msr, "Force using MSR to configure IDE function (Default: 0)");
47 #else
48 #undef rdmsr	/* avoid accidental MSR usage on, e.g. x86-64 */
49 #undef wrmsr
50 #define rdmsr(x, y, z) do { } while (0)
51 #define wrmsr(x, y, z) do { } while (0)
52 #define use_msr 0
53 #endif
54 
55 #define DRV_NAME	"pata_cs5536"
56 #define DRV_VERSION	"0.0.8"
57 
58 enum {
59 	MSR_IDE_CFG		= 0x51300010,
60 	PCI_IDE_CFG		= 0x40,
61 
62 	CFG			= 0,
63 	DTC			= 2,
64 	CAST			= 3,
65 	ETC			= 4,
66 
67 	IDE_CFG_CHANEN		= (1 << 1),
68 	IDE_CFG_CABLE		= (1 << 17) | (1 << 16),
69 
70 	IDE_D0_SHIFT		= 24,
71 	IDE_D1_SHIFT		= 16,
72 	IDE_DRV_MASK		= 0xff,
73 
74 	IDE_CAST_D0_SHIFT	= 6,
75 	IDE_CAST_D1_SHIFT	= 4,
76 	IDE_CAST_DRV_MASK	= 0x3,
77 	IDE_CAST_CMD_MASK	= 0xff,
78 	IDE_CAST_CMD_SHIFT	= 24,
79 
80 	IDE_ETC_UDMA_MASK	= 0xc0,
81 };
82 
83 /* Some Bachmann OT200 devices have a non working UDMA support due a
84  * missing resistor.
85  */
86 static const struct dmi_system_id udma_quirk_dmi_table[] = {
87 	{
88 		.ident = "Bachmann electronic OT200",
89 		.matches = {
90 			DMI_MATCH(DMI_SYS_VENDOR, "Bachmann electronic"),
91 			DMI_MATCH(DMI_PRODUCT_NAME, "OT200"),
92 			DMI_MATCH(DMI_PRODUCT_VERSION, "1")
93 		},
94 	},
95 	{ }
96 };
97 
98 static int cs5536_read(struct pci_dev *pdev, int reg, u32 *val)
99 {
100 	if (unlikely(use_msr)) {
101 		u32 dummy __maybe_unused;
102 
103 		rdmsr(MSR_IDE_CFG + reg, *val, dummy);
104 		return 0;
105 	}
106 
107 	return pci_read_config_dword(pdev, PCI_IDE_CFG + reg * 4, val);
108 }
109 
110 static int cs5536_write(struct pci_dev *pdev, int reg, int val)
111 {
112 	if (unlikely(use_msr)) {
113 		wrmsr(MSR_IDE_CFG + reg, val, 0);
114 		return 0;
115 	}
116 
117 	return pci_write_config_dword(pdev, PCI_IDE_CFG + reg * 4, val);
118 }
119 
120 static void cs5536_program_dtc(struct ata_device *adev, u8 tim)
121 {
122 	struct pci_dev *pdev = to_pci_dev(adev->link->ap->host->dev);
123 	int dshift = adev->devno ? IDE_D1_SHIFT : IDE_D0_SHIFT;
124 	u32 dtc;
125 
126 	cs5536_read(pdev, DTC, &dtc);
127 	dtc &= ~(IDE_DRV_MASK << dshift);
128 	dtc |= tim << dshift;
129 	cs5536_write(pdev, DTC, dtc);
130 }
131 
132 /**
133  *	cs5536_cable_detect	-	detect cable type
134  *	@ap: Port to detect on
135  *
136  *	Perform cable detection for ATA66 capable cable.
137  *
138  *	Returns a cable type.
139  */
140 
141 static int cs5536_cable_detect(struct ata_port *ap)
142 {
143 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
144 	u32 cfg;
145 
146 	cs5536_read(pdev, CFG, &cfg);
147 
148 	if (cfg & IDE_CFG_CABLE)
149 		return ATA_CBL_PATA80;
150 	else
151 		return ATA_CBL_PATA40;
152 }
153 
154 /**
155  *	cs5536_set_piomode		-	PIO setup
156  *	@ap: ATA interface
157  *	@adev: device on the interface
158  */
159 
160 static void cs5536_set_piomode(struct ata_port *ap, struct ata_device *adev)
161 {
162 	static const u8 drv_timings[5] = {
163 		0x98, 0x55, 0x32, 0x21, 0x20,
164 	};
165 
166 	static const u8 addr_timings[5] = {
167 		0x2, 0x1, 0x0, 0x0, 0x0,
168 	};
169 
170 	static const u8 cmd_timings[5] = {
171 		0x99, 0x92, 0x90, 0x22, 0x20,
172 	};
173 
174 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
175 	struct ata_device *pair = ata_dev_pair(adev);
176 	int mode = adev->pio_mode - XFER_PIO_0;
177 	int cmdmode = mode;
178 	int cshift = adev->devno ? IDE_CAST_D1_SHIFT : IDE_CAST_D0_SHIFT;
179 	u32 cast;
180 
181 	if (pair)
182 		cmdmode = min(mode, pair->pio_mode - XFER_PIO_0);
183 
184 	cs5536_program_dtc(adev, drv_timings[mode]);
185 
186 	cs5536_read(pdev, CAST, &cast);
187 
188 	cast &= ~(IDE_CAST_DRV_MASK << cshift);
189 	cast |= addr_timings[mode] << cshift;
190 
191 	cast &= ~(IDE_CAST_CMD_MASK << IDE_CAST_CMD_SHIFT);
192 	cast |= cmd_timings[cmdmode] << IDE_CAST_CMD_SHIFT;
193 
194 	cs5536_write(pdev, CAST, cast);
195 }
196 
197 /**
198  *	cs5536_set_dmamode		-	DMA timing setup
199  *	@ap: ATA interface
200  *	@adev: Device being configured
201  *
202  */
203 
204 static void cs5536_set_dmamode(struct ata_port *ap, struct ata_device *adev)
205 {
206 	static const u8 udma_timings[6] = {
207 		0xc2, 0xc1, 0xc0, 0xc4, 0xc5, 0xc6,
208 	};
209 
210 	static const u8 mwdma_timings[3] = {
211 		0x67, 0x21, 0x20,
212 	};
213 
214 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
215 	u32 etc;
216 	int mode = adev->dma_mode;
217 	int dshift = adev->devno ? IDE_D1_SHIFT : IDE_D0_SHIFT;
218 
219 	cs5536_read(pdev, ETC, &etc);
220 
221 	if (mode >= XFER_UDMA_0) {
222 		etc &= ~(IDE_DRV_MASK << dshift);
223 		etc |= udma_timings[mode - XFER_UDMA_0] << dshift;
224 	} else { /* MWDMA */
225 		etc &= ~(IDE_ETC_UDMA_MASK << dshift);
226 		cs5536_program_dtc(adev, mwdma_timings[mode - XFER_MW_DMA_0]);
227 	}
228 
229 	cs5536_write(pdev, ETC, etc);
230 }
231 
232 static struct scsi_host_template cs5536_sht = {
233 	ATA_BMDMA_SHT(DRV_NAME),
234 };
235 
236 static struct ata_port_operations cs5536_port_ops = {
237 	.inherits		= &ata_bmdma32_port_ops,
238 	.cable_detect		= cs5536_cable_detect,
239 	.set_piomode		= cs5536_set_piomode,
240 	.set_dmamode		= cs5536_set_dmamode,
241 };
242 
243 /**
244  *	cs5536_init_one
245  *	@dev: PCI device
246  *	@id: Entry in match table
247  *
248  */
249 
250 static int cs5536_init_one(struct pci_dev *dev, const struct pci_device_id *id)
251 {
252 	static const struct ata_port_info info = {
253 		.flags = ATA_FLAG_SLAVE_POSS,
254 		.pio_mask = ATA_PIO4,
255 		.mwdma_mask = ATA_MWDMA2,
256 		.udma_mask = ATA_UDMA5,
257 		.port_ops = &cs5536_port_ops,
258 	};
259 
260 	static const struct ata_port_info no_udma_info = {
261 		.flags = ATA_FLAG_SLAVE_POSS,
262 		.pio_mask = ATA_PIO4,
263 		.port_ops = &cs5536_port_ops,
264 	};
265 
266 
267 	const struct ata_port_info *ppi[2];
268 	u32 cfg;
269 
270 	if (dmi_check_system(udma_quirk_dmi_table))
271 		ppi[0] = &no_udma_info;
272 	else
273 		ppi[0] = &info;
274 
275 	ppi[1] = &ata_dummy_port_info;
276 
277 	if (use_msr)
278 		printk(KERN_ERR DRV_NAME ": Using MSR regs instead of PCI\n");
279 
280 	cs5536_read(dev, CFG, &cfg);
281 
282 	if ((cfg & IDE_CFG_CHANEN) == 0) {
283 		printk(KERN_ERR DRV_NAME ": disabled by BIOS\n");
284 		return -ENODEV;
285 	}
286 
287 	return ata_pci_bmdma_init_one(dev, ppi, &cs5536_sht, NULL, 0);
288 }
289 
290 static const struct pci_device_id cs5536[] = {
291 	{ PCI_VDEVICE(AMD,	PCI_DEVICE_ID_AMD_CS5536_IDE), },
292 	{ },
293 };
294 
295 static struct pci_driver cs5536_pci_driver = {
296 	.name		= DRV_NAME,
297 	.id_table	= cs5536,
298 	.probe		= cs5536_init_one,
299 	.remove		= ata_pci_remove_one,
300 #ifdef CONFIG_PM
301 	.suspend	= ata_pci_device_suspend,
302 	.resume		= ata_pci_device_resume,
303 #endif
304 };
305 
306 module_pci_driver(cs5536_pci_driver);
307 
308 MODULE_AUTHOR("Martin K. Petersen");
309 MODULE_DESCRIPTION("low-level driver for the CS5536 IDE controller");
310 MODULE_LICENSE("GPL");
311 MODULE_DEVICE_TABLE(pci, cs5536);
312 MODULE_VERSION(DRV_VERSION);
313