xref: /openbmc/linux/drivers/ata/pata_radisys.c (revision d9679d00)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *    pata_radisys.c - Intel PATA/SATA controllers
4  *
5  *	(C) 2006 Red Hat <alan@lxorguk.ukuu.org.uk>
6  *
7  *    Some parts based on ata_piix.c by Jeff Garzik and others.
8  *
9  *    A PIIX relative, this device has a single ATA channel and no
10  *    slave timings, SITRE or PPE. In that sense it is a close relative
11  *    of the original PIIX. It does however support UDMA 33/66 per channel
12  *    although no other modes/timings. Also lacking is 32bit I/O on the ATA
13  *    port.
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/pci.h>
19 #include <linux/blkdev.h>
20 #include <linux/delay.h>
21 #include <linux/device.h>
22 #include <scsi/scsi_host.h>
23 #include <linux/libata.h>
24 #include <linux/ata.h>
25 
26 #define DRV_NAME	"pata_radisys"
27 #define DRV_VERSION	"0.4.4"
28 
29 /**
30  *	radisys_set_piomode - Initialize host controller PATA PIO timings
31  *	@ap: ATA port
32  *	@adev: Device whose timings we are configuring
33  *
34  *	Set PIO mode for device, in host controller PCI config space.
35  *
36  *	LOCKING:
37  *	None (inherited from caller).
38  */
39 
40 static void radisys_set_piomode (struct ata_port *ap, struct ata_device *adev)
41 {
42 	unsigned int pio	= adev->pio_mode - XFER_PIO_0;
43 	struct pci_dev *dev	= to_pci_dev(ap->host->dev);
44 	u16 idetm_data;
45 	int control = 0;
46 
47 	/*
48 	 *	See Intel Document 298600-004 for the timing programing rules
49 	 *	for PIIX/ICH. Note that the early PIIX does not have the slave
50 	 *	timing port at 0x44. The Radisys is a relative of the PIIX
51 	 *	but not the same so be careful.
52 	 */
53 
54 	static const	 /* ISP  RTC */
55 	u8 timings[][2]	= { { 0, 0 },	/* Check me */
56 			    { 0, 0 },
57 			    { 1, 1 },
58 			    { 2, 2 },
59 			    { 3, 3 }, };
60 
61 	if (pio > 0)
62 		control |= 1;	/* TIME1 enable */
63 	if (ata_pio_need_iordy(adev))
64 		control |= 2;	/* IE IORDY */
65 
66 	pci_read_config_word(dev, 0x40, &idetm_data);
67 
68 	/* Enable IE and TIME as appropriate. Clear the other
69 	   drive timing bits */
70 	idetm_data &= 0xCCCC;
71 	idetm_data |= (control << (4 * adev->devno));
72 	idetm_data |= (timings[pio][0] << 12) |
73 			(timings[pio][1] << 8);
74 	pci_write_config_word(dev, 0x40, idetm_data);
75 
76 	/* Track which port is configured */
77 	ap->private_data = adev;
78 }
79 
80 /**
81  *	radisys_set_dmamode - Initialize host controller PATA DMA timings
82  *	@ap: Port whose timings we are configuring
83  *	@adev: Device to program
84  *
85  *	Set MWDMA mode for device, in host controller PCI config space.
86  *
87  *	LOCKING:
88  *	None (inherited from caller).
89  */
90 
91 static void radisys_set_dmamode (struct ata_port *ap, struct ata_device *adev)
92 {
93 	struct pci_dev *dev	= to_pci_dev(ap->host->dev);
94 	u16 idetm_data;
95 	u8 udma_enable;
96 
97 	static const	 /* ISP  RTC */
98 	u8 timings[][2]	= { { 0, 0 },
99 			    { 0, 0 },
100 			    { 1, 1 },
101 			    { 2, 2 },
102 			    { 3, 3 }, };
103 
104 	/*
105 	 * MWDMA is driven by the PIO timings. We must also enable
106 	 * IORDY unconditionally.
107 	 */
108 
109 	pci_read_config_word(dev, 0x40, &idetm_data);
110 	pci_read_config_byte(dev, 0x48, &udma_enable);
111 
112 	if (adev->dma_mode < XFER_UDMA_0) {
113 		unsigned int mwdma	= adev->dma_mode - XFER_MW_DMA_0;
114 		const unsigned int needed_pio[3] = {
115 			XFER_PIO_0, XFER_PIO_3, XFER_PIO_4
116 		};
117 		int pio = needed_pio[mwdma] - XFER_PIO_0;
118 		int control = 3;	/* IORDY|TIME0 */
119 
120 		/* If the drive MWDMA is faster than it can do PIO then
121 		   we must force PIO0 for PIO cycles. */
122 
123 		if (adev->pio_mode < needed_pio[mwdma])
124 			control = 1;
125 
126 		/* Mask out the relevant control and timing bits we will load. Also
127 		   clear the other drive TIME register as a precaution */
128 
129 		idetm_data &= 0xCCCC;
130 		idetm_data |= control << (4 * adev->devno);
131 		idetm_data |= (timings[pio][0] << 12) | (timings[pio][1] << 8);
132 
133 		udma_enable &= ~(1 << adev->devno);
134 	} else {
135 		u8 udma_mode;
136 
137 		/* UDMA66 on: UDMA 33 and 66 are switchable via register 0x4A */
138 
139 		pci_read_config_byte(dev, 0x4A, &udma_mode);
140 
141 		if (adev->xfer_mode == XFER_UDMA_2)
142 			udma_mode &= ~(2 << (adev->devno * 4));
143 		else /* UDMA 4 */
144 			udma_mode |= (2 << (adev->devno * 4));
145 
146 		pci_write_config_byte(dev, 0x4A, udma_mode);
147 
148 		udma_enable |= (1 << adev->devno);
149 	}
150 	pci_write_config_word(dev, 0x40, idetm_data);
151 	pci_write_config_byte(dev, 0x48, udma_enable);
152 
153 	/* Track which port is configured */
154 	ap->private_data = adev;
155 }
156 
157 /**
158  *	radisys_qc_issue	-	command issue
159  *	@qc: command pending
160  *
161  *	Called when the libata layer is about to issue a command. We wrap
162  *	this interface so that we can load the correct ATA timings if
163  *	necessary. Our logic also clears TIME0/TIME1 for the other device so
164  *	that, even if we get this wrong, cycles to the other device will
165  *	be made PIO0.
166  */
167 
168 static unsigned int radisys_qc_issue(struct ata_queued_cmd *qc)
169 {
170 	struct ata_port *ap = qc->ap;
171 	struct ata_device *adev = qc->dev;
172 
173 	if (adev != ap->private_data) {
174 		/* UDMA timing is not shared */
175 		if (adev->dma_mode < XFER_UDMA_0 || !ata_dma_enabled(adev)) {
176 			if (ata_dma_enabled(adev))
177 				radisys_set_dmamode(ap, adev);
178 			else if (adev->pio_mode)
179 				radisys_set_piomode(ap, adev);
180 		}
181 	}
182 	return ata_bmdma_qc_issue(qc);
183 }
184 
185 
186 static struct scsi_host_template radisys_sht = {
187 	ATA_BMDMA_SHT(DRV_NAME),
188 };
189 
190 static struct ata_port_operations radisys_pata_ops = {
191 	.inherits		= &ata_bmdma_port_ops,
192 	.qc_issue		= radisys_qc_issue,
193 	.cable_detect		= ata_cable_unknown,
194 	.set_piomode		= radisys_set_piomode,
195 	.set_dmamode		= radisys_set_dmamode,
196 };
197 
198 
199 /**
200  *	radisys_init_one - Register PIIX ATA PCI device with kernel services
201  *	@pdev: PCI device to register
202  *	@ent: Entry in radisys_pci_tbl matching with @pdev
203  *
204  *	Called from kernel PCI layer.  We probe for combined mode (sigh),
205  *	and then hand over control to libata, for it to do the rest.
206  *
207  *	LOCKING:
208  *	Inherited from PCI layer (may sleep).
209  *
210  *	RETURNS:
211  *	Zero on success, or -ERRNO value.
212  */
213 
214 static int radisys_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
215 {
216 	static const struct ata_port_info info = {
217 		.flags		= ATA_FLAG_SLAVE_POSS,
218 		.pio_mask	= ATA_PIO4,
219 		.mwdma_mask	= ATA_MWDMA12_ONLY,
220 		.udma_mask	= ATA_UDMA24_ONLY,
221 		.port_ops	= &radisys_pata_ops,
222 	};
223 	const struct ata_port_info *ppi[] = { &info, NULL };
224 
225 	ata_print_version_once(&pdev->dev, DRV_VERSION);
226 
227 	return ata_pci_bmdma_init_one(pdev, ppi, &radisys_sht, NULL, 0);
228 }
229 
230 static const struct pci_device_id radisys_pci_tbl[] = {
231 	{ PCI_VDEVICE(RADISYS, 0x8201), },
232 
233 	{ }	/* terminate list */
234 };
235 
236 static struct pci_driver radisys_pci_driver = {
237 	.name			= DRV_NAME,
238 	.id_table		= radisys_pci_tbl,
239 	.probe			= radisys_init_one,
240 	.remove			= ata_pci_remove_one,
241 #ifdef CONFIG_PM_SLEEP
242 	.suspend		= ata_pci_device_suspend,
243 	.resume			= ata_pci_device_resume,
244 #endif
245 };
246 
247 module_pci_driver(radisys_pci_driver);
248 
249 MODULE_AUTHOR("Alan Cox");
250 MODULE_DESCRIPTION("SCSI low-level driver for Radisys R82600 controllers");
251 MODULE_LICENSE("GPL");
252 MODULE_DEVICE_TABLE(pci, radisys_pci_tbl);
253 MODULE_VERSION(DRV_VERSION);
254