xref: /openbmc/linux/drivers/ata/pata_ixp4xx_cf.c (revision cabce92d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * ixp4xx PATA/Compact Flash driver
4  * Copyright (C) 2006-07 Tower Technologies
5  * Author: Alessandro Zummo <a.zummo@towertech.it>
6  *
7  * An ATA driver to handle a Compact Flash connected
8  * to the ixp4xx expansion bus in TrueIDE mode. The CF
9  * must have it chip selects connected to two CS lines
10  * on the ixp4xx. In the irq is not available, you might
11  * want to modify both this driver and libata to run in
12  * polling mode.
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/mfd/syscon.h>
17 #include <linux/module.h>
18 #include <linux/libata.h>
19 #include <linux/irq.h>
20 #include <linux/of.h>
21 #include <linux/platform_device.h>
22 #include <linux/regmap.h>
23 #include <scsi/scsi_host.h>
24 
25 #define DRV_NAME	"pata_ixp4xx_cf"
26 #define DRV_VERSION	"1.0"
27 
28 struct ixp4xx_pata {
29 	struct ata_host *host;
30 	struct regmap *rmap;
31 	u32 cmd_csreg;
32 	void __iomem *cmd;
33 	void __iomem *ctl;
34 };
35 
36 #define IXP4XX_EXP_TIMING_STRIDE	0x04
37 /* The timings for the chipselect is in bits 29..16 */
38 #define IXP4XX_EXP_T1_T5_MASK	GENMASK(29, 16)
39 #define IXP4XX_EXP_PIO_0_8	0x0a470000
40 #define IXP4XX_EXP_PIO_1_8	0x06430000
41 #define IXP4XX_EXP_PIO_2_8	0x02410000
42 #define IXP4XX_EXP_PIO_3_8	0x00820000
43 #define IXP4XX_EXP_PIO_4_8	0x00400000
44 #define IXP4XX_EXP_PIO_0_16	0x29640000
45 #define IXP4XX_EXP_PIO_1_16	0x05030000
46 #define IXP4XX_EXP_PIO_2_16	0x00b20000
47 #define IXP4XX_EXP_PIO_3_16	0x00820000
48 #define IXP4XX_EXP_PIO_4_16	0x00400000
49 #define IXP4XX_EXP_BW_MASK	(BIT(6)|BIT(0))
50 #define IXP4XX_EXP_BYTE_RD16	BIT(6) /* Byte reads on half-word devices */
51 #define IXP4XX_EXP_BYTE_EN	BIT(0) /* Use 8bit data bus if set */
52 
53 static void ixp4xx_set_8bit_timing(struct ixp4xx_pata *ixpp, u8 pio_mode)
54 {
55 	switch (pio_mode) {
56 	case XFER_PIO_0:
57 		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
58 				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_0_8);
59 		break;
60 	case XFER_PIO_1:
61 		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
62 				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_1_8);
63 		break;
64 	case XFER_PIO_2:
65 		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
66 				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_2_8);
67 		break;
68 	case XFER_PIO_3:
69 		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
70 				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_3_8);
71 		break;
72 	case XFER_PIO_4:
73 		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
74 				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_4_8);
75 		break;
76 	default:
77 		break;
78 	}
79 	regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
80 			   IXP4XX_EXP_BW_MASK, IXP4XX_EXP_BYTE_RD16|IXP4XX_EXP_BYTE_EN);
81 }
82 
83 static void ixp4xx_set_16bit_timing(struct ixp4xx_pata *ixpp, u8 pio_mode)
84 {
85 	switch (pio_mode){
86 	case XFER_PIO_0:
87 		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
88 				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_0_16);
89 		break;
90 	case XFER_PIO_1:
91 		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
92 				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_1_16);
93 		break;
94 	case XFER_PIO_2:
95 		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
96 				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_2_16);
97 		break;
98 	case XFER_PIO_3:
99 		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
100 				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_3_16);
101 		break;
102 	case XFER_PIO_4:
103 		regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
104 				   IXP4XX_EXP_T1_T5_MASK, IXP4XX_EXP_PIO_4_16);
105 		break;
106 	default:
107 		break;
108 	}
109 	regmap_update_bits(ixpp->rmap, ixpp->cmd_csreg,
110 			   IXP4XX_EXP_BW_MASK, IXP4XX_EXP_BYTE_RD16);
111 }
112 
113 /* This sets up the timing on the chipselect CMD accordingly */
114 static void ixp4xx_set_piomode(struct ata_port *ap, struct ata_device *adev)
115 {
116 	struct ixp4xx_pata *ixpp = ap->host->private_data;
117 
118 	ata_dev_info(adev, "configured for PIO%d 8bit\n",
119 		       adev->pio_mode - XFER_PIO_0);
120 	ixp4xx_set_8bit_timing(ixpp, adev->pio_mode);
121 }
122 
123 
124 static unsigned int ixp4xx_mmio_data_xfer(struct ata_queued_cmd *qc,
125 					  unsigned char *buf, unsigned int buflen, int rw)
126 {
127 	unsigned int i;
128 	unsigned int words = buflen >> 1;
129 	u16 *buf16 = (u16 *) buf;
130 	struct ata_device *adev = qc->dev;
131 	struct ata_port *ap = qc->dev->link->ap;
132 	void __iomem *mmio = ap->ioaddr.data_addr;
133 	struct ixp4xx_pata *ixpp = ap->host->private_data;
134 	unsigned long flags;
135 
136 	ata_dev_dbg(adev, "%s %d bytes\n", (rw == READ) ? "READ" : "WRITE",
137 		    buflen);
138 	spin_lock_irqsave(ap->lock, flags);
139 
140 	/* set the expansion bus in 16bit mode and restore
141 	 * 8 bit mode after the transaction.
142 	 */
143 	ixp4xx_set_16bit_timing(ixpp, adev->pio_mode);
144 	udelay(5);
145 
146 	/* Transfer multiple of 2 bytes */
147 	if (rw == READ)
148 		for (i = 0; i < words; i++)
149 			buf16[i] = readw(mmio);
150 	else
151 		for (i = 0; i < words; i++)
152 			writew(buf16[i], mmio);
153 
154 	/* Transfer trailing 1 byte, if any. */
155 	if (unlikely(buflen & 0x01)) {
156 		u16 align_buf[1] = { 0 };
157 		unsigned char *trailing_buf = buf + buflen - 1;
158 
159 		if (rw == READ) {
160 			align_buf[0] = readw(mmio);
161 			memcpy(trailing_buf, align_buf, 1);
162 		} else {
163 			memcpy(align_buf, trailing_buf, 1);
164 			writew(align_buf[0], mmio);
165 		}
166 		words++;
167 	}
168 
169 	ixp4xx_set_8bit_timing(ixpp, adev->pio_mode);
170 	udelay(5);
171 
172 	spin_unlock_irqrestore(ap->lock, flags);
173 
174 	return words << 1;
175 }
176 
177 static const struct scsi_host_template ixp4xx_sht = {
178 	ATA_PIO_SHT(DRV_NAME),
179 };
180 
181 static struct ata_port_operations ixp4xx_port_ops = {
182 	.inherits		= &ata_sff_port_ops,
183 	.sff_data_xfer		= ixp4xx_mmio_data_xfer,
184 	.cable_detect		= ata_cable_40wire,
185 	.set_piomode		= ixp4xx_set_piomode,
186 };
187 
188 static struct ata_port_info ixp4xx_port_info = {
189 	.flags		= ATA_FLAG_NO_ATAPI,
190 	.pio_mask	= ATA_PIO4,
191 	.port_ops	= &ixp4xx_port_ops,
192 };
193 
194 static void ixp4xx_setup_port(struct ata_port *ap,
195 			      struct ixp4xx_pata *ixpp,
196 			      unsigned long raw_cmd, unsigned long raw_ctl)
197 {
198 	struct ata_ioports *ioaddr = &ap->ioaddr;
199 
200 	raw_ctl += 0x06;
201 	ioaddr->cmd_addr	= ixpp->cmd;
202 	ioaddr->altstatus_addr	= ixpp->ctl + 0x06;
203 	ioaddr->ctl_addr	= ixpp->ctl + 0x06;
204 
205 	ata_sff_std_ports(ioaddr);
206 
207 	if (!IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) {
208 		/* adjust the addresses to handle the address swizzling of the
209 		 * ixp4xx in little endian mode.
210 		 */
211 
212 		*(unsigned long *)&ioaddr->data_addr		^= 0x02;
213 		*(unsigned long *)&ioaddr->cmd_addr		^= 0x03;
214 		*(unsigned long *)&ioaddr->altstatus_addr	^= 0x03;
215 		*(unsigned long *)&ioaddr->ctl_addr		^= 0x03;
216 		*(unsigned long *)&ioaddr->error_addr		^= 0x03;
217 		*(unsigned long *)&ioaddr->feature_addr		^= 0x03;
218 		*(unsigned long *)&ioaddr->nsect_addr		^= 0x03;
219 		*(unsigned long *)&ioaddr->lbal_addr		^= 0x03;
220 		*(unsigned long *)&ioaddr->lbam_addr		^= 0x03;
221 		*(unsigned long *)&ioaddr->lbah_addr		^= 0x03;
222 		*(unsigned long *)&ioaddr->device_addr		^= 0x03;
223 		*(unsigned long *)&ioaddr->status_addr		^= 0x03;
224 		*(unsigned long *)&ioaddr->command_addr		^= 0x03;
225 
226 		raw_cmd ^= 0x03;
227 		raw_ctl ^= 0x03;
228 	}
229 
230 	ata_port_desc(ap, "cmd 0x%lx ctl 0x%lx", raw_cmd, raw_ctl);
231 }
232 
233 static int ixp4xx_pata_probe(struct platform_device *pdev)
234 {
235 	struct resource *cmd, *ctl;
236 	struct ata_port_info pi = ixp4xx_port_info;
237 	const struct ata_port_info *ppi[] = { &pi, NULL };
238 	struct device *dev = &pdev->dev;
239 	struct device_node *np = dev->of_node;
240 	struct ixp4xx_pata *ixpp;
241 	u32 csindex;
242 	int ret;
243 	int irq;
244 
245 	cmd = platform_get_resource(pdev, IORESOURCE_MEM, 0);
246 	ctl = platform_get_resource(pdev, IORESOURCE_MEM, 1);
247 
248 	if (!cmd || !ctl)
249 		return -EINVAL;
250 
251 	ixpp = devm_kzalloc(dev, sizeof(*ixpp), GFP_KERNEL);
252 	if (!ixpp)
253 		return -ENOMEM;
254 
255 	ixpp->rmap = syscon_node_to_regmap(np->parent);
256 	if (IS_ERR(ixpp->rmap))
257 		return dev_err_probe(dev, PTR_ERR(ixpp->rmap), "no regmap\n");
258 	/* Inspect our address to figure out what chipselect the CMD is on */
259 	ret = of_property_read_u32_index(np, "reg", 0, &csindex);
260 	if (ret)
261 		return dev_err_probe(dev, ret, "can't inspect CMD address\n");
262 	dev_info(dev, "using CS%d for PIO timing configuration\n", csindex);
263 	ixpp->cmd_csreg = csindex * IXP4XX_EXP_TIMING_STRIDE;
264 
265 	ixpp->host = ata_host_alloc_pinfo(dev, ppi, 1);
266 	if (!ixpp->host)
267 		return -ENOMEM;
268 	ixpp->host->private_data = ixpp;
269 
270 	ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
271 	if (ret)
272 		return ret;
273 
274 	ixpp->cmd = devm_ioremap_resource(dev, cmd);
275 	ixpp->ctl = devm_ioremap_resource(dev, ctl);
276 	if (IS_ERR(ixpp->cmd) || IS_ERR(ixpp->ctl))
277 		return -ENOMEM;
278 
279 	irq = platform_get_irq(pdev, 0);
280 	if (irq > 0)
281 		irq_set_irq_type(irq, IRQ_TYPE_EDGE_RISING);
282 	else if (irq < 0)
283 		return irq;
284 	else
285 		return -EINVAL;
286 
287 	/* Just one port to set up */
288 	ixp4xx_setup_port(ixpp->host->ports[0], ixpp, cmd->start, ctl->start);
289 
290 	ata_print_version_once(dev, DRV_VERSION);
291 
292 	return ata_host_activate(ixpp->host, irq, ata_sff_interrupt, 0, &ixp4xx_sht);
293 }
294 
295 static const struct of_device_id ixp4xx_pata_of_match[] = {
296 	{ .compatible = "intel,ixp4xx-compact-flash", },
297 	{ /* sentinel */ }
298 };
299 
300 static struct platform_driver ixp4xx_pata_platform_driver = {
301 	.driver	 = {
302 		.name   = DRV_NAME,
303 		.of_match_table = ixp4xx_pata_of_match,
304 	},
305 	.probe		= ixp4xx_pata_probe,
306 	.remove_new	= ata_platform_remove_one,
307 };
308 
309 module_platform_driver(ixp4xx_pata_platform_driver);
310 
311 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
312 MODULE_DESCRIPTION("low-level driver for ixp4xx Compact Flash PATA");
313 MODULE_LICENSE("GPL");
314 MODULE_VERSION(DRV_VERSION);
315 MODULE_ALIAS("platform:" DRV_NAME);
316