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>
44static int use_msr;
45module_param_named(msr, use_msr, int, 0644);
46MODULE_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
58enum {
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 */
86static 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
98static 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
110static 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
120static 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
141static 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
160static 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
204static 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
232static struct scsi_host_template cs5536_sht = {
233	ATA_BMDMA_SHT(DRV_NAME),
234};
235
236static 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
250static 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
290static const struct pci_device_id cs5536[] = {
291	{ PCI_VDEVICE(AMD,	PCI_DEVICE_ID_AMD_CS5536_IDE), },
292	{ },
293};
294
295static 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_SLEEP
301	.suspend	= ata_pci_device_suspend,
302	.resume		= ata_pci_device_resume,
303#endif
304};
305
306module_pci_driver(cs5536_pci_driver);
307
308MODULE_AUTHOR("Martin K. Petersen");
309MODULE_DESCRIPTION("low-level driver for the CS5536 IDE controller");
310MODULE_LICENSE("GPL");
311MODULE_DEVICE_TABLE(pci, cs5536);
312MODULE_VERSION(DRV_VERSION);
313