xref: /openbmc/linux/drivers/ata/pata_cs5536.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2  * pata_cs5536.c	- CS5536 PATA for new ATA layer
3  *			  (C) 2007 Martin K. Petersen <mkp@mkp.net>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307	 USA
17  *
18  * Documentation:
19  *	Available from AMD web site.
20  *
21  * The IDE timing registers for the CS5536 live in the Geode Machine
22  * Specific Register file and not PCI config space.  Most BIOSes
23  * virtualize the PCI registers so the chip looks like a standard IDE
24  * controller.	Unfortunately not all implementations get this right.
25  * In particular some have problems with unaligned accesses to the
26  * virtualized PCI registers.  This driver always does full dword
27  * writes to work around the issue.  Also, in case of a bad BIOS this
28  * driver can be loaded with the "msr=1" parameter which forces using
29  * the Machine Specific Registers to configure the device.
30  */
31 
32 #include <linux/kernel.h>
33 #include <linux/module.h>
34 #include <linux/pci.h>
35 #include <linux/init.h>
36 #include <linux/blkdev.h>
37 #include <linux/delay.h>
38 #include <linux/libata.h>
39 #include <scsi/scsi_host.h>
40 
41 #ifdef CONFIG_X86_32
42 #include <asm/msr.h>
43 static int use_msr;
44 module_param_named(msr, use_msr, int, 0644);
45 MODULE_PARM_DESC(msr, "Force using MSR to configure IDE function (Default: 0)");
46 #else
47 #undef rdmsr	/* avoid accidental MSR usage on, e.g. x86-64 */
48 #undef wrmsr
49 #define rdmsr(x, y, z) do { } while (0)
50 #define wrmsr(x, y, z) do { } while (0)
51 #define use_msr 0
52 #endif
53 
54 #define DRV_NAME	"pata_cs5536"
55 #define DRV_VERSION	"0.0.8"
56 
57 enum {
58 	CFG			= 0,
59 	DTC			= 1,
60 	CAST			= 2,
61 	ETC			= 3,
62 
63 	MSR_IDE_BASE		= 0x51300000,
64 	MSR_IDE_CFG		= (MSR_IDE_BASE + 0x10),
65 	MSR_IDE_DTC		= (MSR_IDE_BASE + 0x12),
66 	MSR_IDE_CAST		= (MSR_IDE_BASE + 0x13),
67 	MSR_IDE_ETC		= (MSR_IDE_BASE + 0x14),
68 
69 	PCI_IDE_CFG		= 0x40,
70 	PCI_IDE_DTC		= 0x48,
71 	PCI_IDE_CAST		= 0x4c,
72 	PCI_IDE_ETC		= 0x50,
73 
74 	IDE_CFG_CHANEN		= 0x2,
75 	IDE_CFG_CABLE		= 0x10000,
76 
77 	IDE_D0_SHIFT		= 24,
78 	IDE_D1_SHIFT		= 16,
79 	IDE_DRV_MASK		= 0xff,
80 
81 	IDE_CAST_D0_SHIFT	= 6,
82 	IDE_CAST_D1_SHIFT	= 4,
83 	IDE_CAST_DRV_MASK	= 0x3,
84 	IDE_CAST_CMD_MASK	= 0xff,
85 	IDE_CAST_CMD_SHIFT	= 24,
86 
87 	IDE_ETC_NODMA		= 0x03,
88 };
89 
90 static const u32 msr_reg[4] = {
91 	MSR_IDE_CFG, MSR_IDE_DTC, MSR_IDE_CAST, MSR_IDE_ETC,
92 };
93 
94 static const u8 pci_reg[4] = {
95 	PCI_IDE_CFG, PCI_IDE_DTC, PCI_IDE_CAST, PCI_IDE_ETC,
96 };
97 
98 static inline 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_reg[reg], *val, dummy);
104 		return 0;
105 	}
106 
107 	return pci_read_config_dword(pdev, pci_reg[reg], val);
108 }
109 
110 static inline int cs5536_write(struct pci_dev *pdev, int reg, int val)
111 {
112 	if (unlikely(use_msr)) {
113 		wrmsr(msr_reg[reg], val, 0);
114 		return 0;
115 	}
116 
117 	return pci_write_config_dword(pdev, pci_reg[reg], val);
118 }
119 
120 /**
121  *	cs5536_cable_detect	-	detect cable type
122  *	@ap: Port to detect on
123  *
124  *	Perform cable detection for ATA66 capable cable. Return a libata
125  *	cable type.
126  */
127 
128 static int cs5536_cable_detect(struct ata_port *ap)
129 {
130 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
131 	u32 cfg;
132 
133 	cs5536_read(pdev, CFG, &cfg);
134 
135 	if (cfg & (IDE_CFG_CABLE << ap->port_no))
136 		return ATA_CBL_PATA80;
137 	else
138 		return ATA_CBL_PATA40;
139 }
140 
141 /**
142  *	cs5536_set_piomode		-	PIO setup
143  *	@ap: ATA interface
144  *	@adev: device on the interface
145  */
146 
147 static void cs5536_set_piomode(struct ata_port *ap, struct ata_device *adev)
148 {
149 	static const u8 drv_timings[5] = {
150 		0x98, 0x55, 0x32, 0x21, 0x20,
151 	};
152 
153 	static const u8 addr_timings[5] = {
154 		0x2, 0x1, 0x0, 0x0, 0x0,
155 	};
156 
157 	static const u8 cmd_timings[5] = {
158 		0x99, 0x92, 0x90, 0x22, 0x20,
159 	};
160 
161 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
162 	struct ata_device *pair = ata_dev_pair(adev);
163 	int mode = adev->pio_mode - XFER_PIO_0;
164 	int cmdmode = mode;
165 	int dshift = adev->devno ? IDE_D1_SHIFT : IDE_D0_SHIFT;
166 	int cshift = adev->devno ? IDE_CAST_D1_SHIFT : IDE_CAST_D0_SHIFT;
167 	u32 dtc, cast, etc;
168 
169 	if (pair)
170 		cmdmode = min(mode, pair->pio_mode - XFER_PIO_0);
171 
172 	cs5536_read(pdev, DTC, &dtc);
173 	cs5536_read(pdev, CAST, &cast);
174 	cs5536_read(pdev, ETC, &etc);
175 
176 	dtc &= ~(IDE_DRV_MASK << dshift);
177 	dtc |= drv_timings[mode] << dshift;
178 
179 	cast &= ~(IDE_CAST_DRV_MASK << cshift);
180 	cast |= addr_timings[mode] << cshift;
181 
182 	cast &= ~(IDE_CAST_CMD_MASK << IDE_CAST_CMD_SHIFT);
183 	cast |= cmd_timings[cmdmode] << IDE_CAST_CMD_SHIFT;
184 
185 	etc &= ~(IDE_DRV_MASK << dshift);
186 	etc |= IDE_ETC_NODMA << dshift;
187 
188 	cs5536_write(pdev, DTC, dtc);
189 	cs5536_write(pdev, CAST, cast);
190 	cs5536_write(pdev, ETC, etc);
191 }
192 
193 /**
194  *	cs5536_set_dmamode		-	DMA timing setup
195  *	@ap: ATA interface
196  *	@adev: Device being configured
197  *
198  */
199 
200 static void cs5536_set_dmamode(struct ata_port *ap, struct ata_device *adev)
201 {
202 	static const u8 udma_timings[6] = {
203 		0xc2, 0xc1, 0xc0, 0xc4, 0xc5, 0xc6,
204 	};
205 
206 	static const u8 mwdma_timings[3] = {
207 		0x67, 0x21, 0x20,
208 	};
209 
210 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
211 	u32 dtc, etc;
212 	int mode = adev->dma_mode;
213 	int dshift = adev->devno ? IDE_D1_SHIFT : IDE_D0_SHIFT;
214 
215 	if (mode >= XFER_UDMA_0) {
216 		cs5536_read(pdev, ETC, &etc);
217 
218 		etc &= ~(IDE_DRV_MASK << dshift);
219 		etc |= udma_timings[mode - XFER_UDMA_0] << dshift;
220 
221 		cs5536_write(pdev, ETC, etc);
222 	} else { /* MWDMA */
223 		cs5536_read(pdev, DTC, &dtc);
224 
225 		dtc &= ~(IDE_DRV_MASK << dshift);
226 		dtc |= mwdma_timings[mode - XFER_MW_DMA_0] << dshift;
227 
228 		cs5536_write(pdev, DTC, dtc);
229 	}
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 	const struct ata_port_info *ppi[] = { &info, &ata_dummy_port_info };
261 	u32 cfg;
262 
263 	if (use_msr)
264 		printk(KERN_ERR DRV_NAME ": Using MSR regs instead of PCI\n");
265 
266 	cs5536_read(dev, CFG, &cfg);
267 
268 	if ((cfg & IDE_CFG_CHANEN) == 0) {
269 		printk(KERN_ERR DRV_NAME ": disabled by BIOS\n");
270 		return -ENODEV;
271 	}
272 
273 	return ata_pci_bmdma_init_one(dev, ppi, &cs5536_sht, NULL, 0);
274 }
275 
276 static const struct pci_device_id cs5536[] = {
277 	{ PCI_VDEVICE(AMD,	PCI_DEVICE_ID_AMD_CS5536_IDE), },
278 	{ },
279 };
280 
281 static struct pci_driver cs5536_pci_driver = {
282 	.name		= DRV_NAME,
283 	.id_table	= cs5536,
284 	.probe		= cs5536_init_one,
285 	.remove		= ata_pci_remove_one,
286 #ifdef CONFIG_PM
287 	.suspend	= ata_pci_device_suspend,
288 	.resume		= ata_pci_device_resume,
289 #endif
290 };
291 
292 static int __init cs5536_init(void)
293 {
294 	return pci_register_driver(&cs5536_pci_driver);
295 }
296 
297 static void __exit cs5536_exit(void)
298 {
299 	pci_unregister_driver(&cs5536_pci_driver);
300 }
301 
302 MODULE_AUTHOR("Martin K. Petersen");
303 MODULE_DESCRIPTION("low-level driver for the CS5536 IDE controller");
304 MODULE_LICENSE("GPL");
305 MODULE_DEVICE_TABLE(pci, cs5536);
306 MODULE_VERSION(DRV_VERSION);
307 
308 module_init(cs5536_init);
309 module_exit(cs5536_exit);
310