xref: /openbmc/linux/drivers/ata/pata_cs5536.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * pata_cs5536.c	- CS5536 PATA for new ATA layer
4  *			  (C) 2007 Martin K. Petersen <mkp@mkp.net>
5  *			  (C) 2011 Bartlomiej Zolnierkiewicz
6  *
7  * Documentation:
8  *	Available from AMD web site.
9  *
10  * The IDE timing registers for the CS5536 live in the Geode Machine
11  * Specific Register file and not PCI config space.  Most BIOSes
12  * virtualize the PCI registers so the chip looks like a standard IDE
13  * controller.	Unfortunately not all implementations get this right.
14  * In particular some have problems with unaligned accesses to the
15  * virtualized PCI registers.  This driver always does full dword
16  * writes to work around the issue.  Also, in case of a bad BIOS this
17  * driver can be loaded with the "msr=1" parameter which forces using
18  * the Machine Specific Registers to configure the device.
19  */
20 
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/pci.h>
24 #include <linux/blkdev.h>
25 #include <linux/delay.h>
26 #include <linux/libata.h>
27 #include <scsi/scsi_host.h>
28 #include <linux/dmi.h>
29 
30 #ifdef CONFIG_X86_32
31 #include <asm/msr.h>
32 static int use_msr;
33 module_param_named(msr, use_msr, int, 0644);
34 MODULE_PARM_DESC(msr, "Force using MSR to configure IDE function (Default: 0)");
35 #else
36 #undef rdmsr	/* avoid accidental MSR usage on, e.g. x86-64 */
37 #undef wrmsr
38 #define rdmsr(x, y, z) do { } while (0)
39 #define wrmsr(x, y, z) do { } while (0)
40 #define use_msr 0
41 #endif
42 
43 #define DRV_NAME	"pata_cs5536"
44 #define DRV_VERSION	"0.0.8"
45 
46 enum {
47 	MSR_IDE_CFG		= 0x51300010,
48 	PCI_IDE_CFG		= 0x40,
49 
50 	CFG			= 0,
51 	DTC			= 2,
52 	CAST			= 3,
53 	ETC			= 4,
54 
55 	IDE_CFG_CHANEN		= (1 << 1),
56 	IDE_CFG_CABLE		= (1 << 17) | (1 << 16),
57 
58 	IDE_D0_SHIFT		= 24,
59 	IDE_D1_SHIFT		= 16,
60 	IDE_DRV_MASK		= 0xff,
61 
62 	IDE_CAST_D0_SHIFT	= 6,
63 	IDE_CAST_D1_SHIFT	= 4,
64 	IDE_CAST_DRV_MASK	= 0x3,
65 	IDE_CAST_CMD_MASK	= 0xff,
66 	IDE_CAST_CMD_SHIFT	= 24,
67 
68 	IDE_ETC_UDMA_MASK	= 0xc0,
69 };
70 
71 /* Some Bachmann OT200 devices have a non working UDMA support due a
72  * missing resistor.
73  */
74 static const struct dmi_system_id udma_quirk_dmi_table[] = {
75 	{
76 		.ident = "Bachmann electronic OT200",
77 		.matches = {
78 			DMI_MATCH(DMI_SYS_VENDOR, "Bachmann electronic"),
79 			DMI_MATCH(DMI_PRODUCT_NAME, "OT200"),
80 			DMI_MATCH(DMI_PRODUCT_VERSION, "1")
81 		},
82 	},
83 	{ }
84 };
85 
86 static int cs5536_read(struct pci_dev *pdev, int reg, u32 *val)
87 {
88 	if (unlikely(use_msr)) {
89 		u32 dummy __maybe_unused;
90 
91 		rdmsr(MSR_IDE_CFG + reg, *val, dummy);
92 		return 0;
93 	}
94 
95 	return pci_read_config_dword(pdev, PCI_IDE_CFG + reg * 4, val);
96 }
97 
98 static int cs5536_write(struct pci_dev *pdev, int reg, int val)
99 {
100 	if (unlikely(use_msr)) {
101 		wrmsr(MSR_IDE_CFG + reg, val, 0);
102 		return 0;
103 	}
104 
105 	return pci_write_config_dword(pdev, PCI_IDE_CFG + reg * 4, val);
106 }
107 
108 static void cs5536_program_dtc(struct ata_device *adev, u8 tim)
109 {
110 	struct pci_dev *pdev = to_pci_dev(adev->link->ap->host->dev);
111 	int dshift = adev->devno ? IDE_D1_SHIFT : IDE_D0_SHIFT;
112 	u32 dtc;
113 
114 	cs5536_read(pdev, DTC, &dtc);
115 	dtc &= ~(IDE_DRV_MASK << dshift);
116 	dtc |= tim << dshift;
117 	cs5536_write(pdev, DTC, dtc);
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.
125  *
126  *	Returns a cable type.
127  */
128 
129 static int cs5536_cable_detect(struct ata_port *ap)
130 {
131 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
132 	u32 cfg;
133 
134 	cs5536_read(pdev, CFG, &cfg);
135 
136 	if (cfg & IDE_CFG_CABLE)
137 		return ATA_CBL_PATA80;
138 	else
139 		return ATA_CBL_PATA40;
140 }
141 
142 /**
143  *	cs5536_set_piomode		-	PIO setup
144  *	@ap: ATA interface
145  *	@adev: device on the interface
146  */
147 
148 static void cs5536_set_piomode(struct ata_port *ap, struct ata_device *adev)
149 {
150 	static const u8 drv_timings[5] = {
151 		0x98, 0x55, 0x32, 0x21, 0x20,
152 	};
153 
154 	static const u8 addr_timings[5] = {
155 		0x2, 0x1, 0x0, 0x0, 0x0,
156 	};
157 
158 	static const u8 cmd_timings[5] = {
159 		0x99, 0x92, 0x90, 0x22, 0x20,
160 	};
161 
162 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
163 	struct ata_device *pair = ata_dev_pair(adev);
164 	int mode = adev->pio_mode - XFER_PIO_0;
165 	int cmdmode = mode;
166 	int cshift = adev->devno ? IDE_CAST_D1_SHIFT : IDE_CAST_D0_SHIFT;
167 	u32 cast;
168 
169 	if (pair)
170 		cmdmode = min(mode, pair->pio_mode - XFER_PIO_0);
171 
172 	cs5536_program_dtc(adev, drv_timings[mode]);
173 
174 	cs5536_read(pdev, CAST, &cast);
175 
176 	cast &= ~(IDE_CAST_DRV_MASK << cshift);
177 	cast |= addr_timings[mode] << cshift;
178 
179 	cast &= ~(IDE_CAST_CMD_MASK << IDE_CAST_CMD_SHIFT);
180 	cast |= cmd_timings[cmdmode] << IDE_CAST_CMD_SHIFT;
181 
182 	cs5536_write(pdev, CAST, cast);
183 }
184 
185 /**
186  *	cs5536_set_dmamode		-	DMA timing setup
187  *	@ap: ATA interface
188  *	@adev: Device being configured
189  *
190  */
191 
192 static void cs5536_set_dmamode(struct ata_port *ap, struct ata_device *adev)
193 {
194 	static const u8 udma_timings[6] = {
195 		0xc2, 0xc1, 0xc0, 0xc4, 0xc5, 0xc6,
196 	};
197 
198 	static const u8 mwdma_timings[3] = {
199 		0x67, 0x21, 0x20,
200 	};
201 
202 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
203 	u32 etc;
204 	int mode = adev->dma_mode;
205 	int dshift = adev->devno ? IDE_D1_SHIFT : IDE_D0_SHIFT;
206 
207 	cs5536_read(pdev, ETC, &etc);
208 
209 	if (mode >= XFER_UDMA_0) {
210 		etc &= ~(IDE_DRV_MASK << dshift);
211 		etc |= udma_timings[mode - XFER_UDMA_0] << dshift;
212 	} else { /* MWDMA */
213 		etc &= ~(IDE_ETC_UDMA_MASK << dshift);
214 		cs5536_program_dtc(adev, mwdma_timings[mode - XFER_MW_DMA_0]);
215 	}
216 
217 	cs5536_write(pdev, ETC, etc);
218 }
219 
220 static struct scsi_host_template cs5536_sht = {
221 	ATA_BMDMA_SHT(DRV_NAME),
222 };
223 
224 static struct ata_port_operations cs5536_port_ops = {
225 	.inherits		= &ata_bmdma32_port_ops,
226 	.cable_detect		= cs5536_cable_detect,
227 	.set_piomode		= cs5536_set_piomode,
228 	.set_dmamode		= cs5536_set_dmamode,
229 };
230 
231 /**
232  *	cs5536_init_one
233  *	@dev: PCI device
234  *	@id: Entry in match table
235  *
236  */
237 
238 static int cs5536_init_one(struct pci_dev *dev, const struct pci_device_id *id)
239 {
240 	static const struct ata_port_info info = {
241 		.flags = ATA_FLAG_SLAVE_POSS,
242 		.pio_mask = ATA_PIO4,
243 		.mwdma_mask = ATA_MWDMA2,
244 		.udma_mask = ATA_UDMA5,
245 		.port_ops = &cs5536_port_ops,
246 	};
247 
248 	static const struct ata_port_info no_udma_info = {
249 		.flags = ATA_FLAG_SLAVE_POSS,
250 		.pio_mask = ATA_PIO4,
251 		.port_ops = &cs5536_port_ops,
252 	};
253 
254 
255 	const struct ata_port_info *ppi[2];
256 	u32 cfg;
257 
258 	if (dmi_check_system(udma_quirk_dmi_table))
259 		ppi[0] = &no_udma_info;
260 	else
261 		ppi[0] = &info;
262 
263 	ppi[1] = &ata_dummy_port_info;
264 
265 	if (use_msr)
266 		dev_err(&dev->dev, DRV_NAME ": Using MSR regs instead of PCI\n");
267 
268 	cs5536_read(dev, CFG, &cfg);
269 
270 	if ((cfg & IDE_CFG_CHANEN) == 0) {
271 		dev_err(&dev->dev, DRV_NAME ": disabled by BIOS\n");
272 		return -ENODEV;
273 	}
274 
275 	return ata_pci_bmdma_init_one(dev, ppi, &cs5536_sht, NULL, 0);
276 }
277 
278 static const struct pci_device_id cs5536[] = {
279 	{ PCI_VDEVICE(AMD,	PCI_DEVICE_ID_AMD_CS5536_IDE), },
280 	{ PCI_VDEVICE(AMD,	PCI_DEVICE_ID_AMD_CS5536_DEV_IDE), },
281 	{ },
282 };
283 
284 static struct pci_driver cs5536_pci_driver = {
285 	.name		= DRV_NAME,
286 	.id_table	= cs5536,
287 	.probe		= cs5536_init_one,
288 	.remove		= ata_pci_remove_one,
289 #ifdef CONFIG_PM_SLEEP
290 	.suspend	= ata_pci_device_suspend,
291 	.resume		= ata_pci_device_resume,
292 #endif
293 };
294 
295 module_pci_driver(cs5536_pci_driver);
296 
297 MODULE_AUTHOR("Martin K. Petersen");
298 MODULE_DESCRIPTION("low-level driver for the CS5536 IDE controller");
299 MODULE_LICENSE("GPL");
300 MODULE_DEVICE_TABLE(pci, cs5536);
301 MODULE_VERSION(DRV_VERSION);
302