xref: /openbmc/linux/drivers/mfd/janz-cmodio.c (revision 28f65c11)
1 /*
2  * Janz CMOD-IO MODULbus Carrier Board PCI Driver
3  *
4  * Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu>
5  *
6  * Lots of inspiration and code was copied from drivers/mfd/sm501.c
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License as published by the
10  * Free Software Foundation; either version 2 of the License, or (at your
11  * option) any later version.
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/pci.h>
18 #include <linux/interrupt.h>
19 #include <linux/delay.h>
20 #include <linux/platform_device.h>
21 #include <linux/slab.h>
22 #include <linux/mfd/core.h>
23 
24 #include <linux/mfd/janz.h>
25 
26 #define DRV_NAME "janz-cmodio"
27 
28 /* Size of each MODULbus module in PCI BAR4 */
29 #define CMODIO_MODULBUS_SIZE	0x200
30 
31 /* Maximum number of MODULbus modules on a CMOD-IO carrier board */
32 #define CMODIO_MAX_MODULES	4
33 
34 /* Module Parameters */
35 static unsigned int num_modules = CMODIO_MAX_MODULES;
36 static unsigned char *modules[CMODIO_MAX_MODULES] = {
37 	"empty", "empty", "empty", "empty",
38 };
39 
40 module_param_array(modules, charp, &num_modules, S_IRUGO);
41 MODULE_PARM_DESC(modules, "MODULbus modules attached to the carrier board");
42 
43 /* Unique Device Id */
44 static unsigned int cmodio_id;
45 
46 struct cmodio_device {
47 	/* Parent PCI device */
48 	struct pci_dev *pdev;
49 
50 	/* PLX control registers */
51 	struct janz_cmodio_onboard_regs __iomem *ctrl;
52 
53 	/* hex switch position */
54 	u8 hex;
55 
56 	/* mfd-core API */
57 	struct mfd_cell cells[CMODIO_MAX_MODULES];
58 	struct resource resources[3 * CMODIO_MAX_MODULES];
59 	struct janz_platform_data pdata[CMODIO_MAX_MODULES];
60 };
61 
62 /*
63  * Subdevices using the mfd-core API
64  */
65 
66 static int __devinit cmodio_setup_subdevice(struct cmodio_device *priv,
67 					    char *name, unsigned int devno,
68 					    unsigned int modno)
69 {
70 	struct janz_platform_data *pdata;
71 	struct mfd_cell *cell;
72 	struct resource *res;
73 	struct pci_dev *pci;
74 
75 	pci = priv->pdev;
76 	cell = &priv->cells[devno];
77 	res = &priv->resources[devno * 3];
78 	pdata = &priv->pdata[devno];
79 
80 	cell->name = name;
81 	cell->resources = res;
82 	cell->num_resources = 3;
83 
84 	/* Setup the subdevice ID -- must be unique */
85 	cell->id = cmodio_id++;
86 
87 	/* Add platform data */
88 	pdata->modno = modno;
89 	cell->platform_data = pdata;
90 	cell->pdata_size = sizeof(*pdata);
91 
92 	/* MODULbus registers -- PCI BAR3 is big-endian MODULbus access */
93 	res->flags = IORESOURCE_MEM;
94 	res->parent = &pci->resource[3];
95 	res->start = pci->resource[3].start + (CMODIO_MODULBUS_SIZE * modno);
96 	res->end = res->start + CMODIO_MODULBUS_SIZE - 1;
97 	res++;
98 
99 	/* PLX Control Registers -- PCI BAR4 is interrupt and other registers */
100 	res->flags = IORESOURCE_MEM;
101 	res->parent = &pci->resource[4];
102 	res->start = pci->resource[4].start;
103 	res->end = pci->resource[4].end;
104 	res++;
105 
106 	/*
107 	 * IRQ
108 	 *
109 	 * The start and end fields are used as an offset to the irq_base
110 	 * parameter passed into the mfd_add_devices() function call. All
111 	 * devices share the same IRQ.
112 	 */
113 	res->flags = IORESOURCE_IRQ;
114 	res->parent = NULL;
115 	res->start = 0;
116 	res->end = 0;
117 	res++;
118 
119 	return 0;
120 }
121 
122 /* Probe each submodule using kernel parameters */
123 static int __devinit cmodio_probe_submodules(struct cmodio_device *priv)
124 {
125 	struct pci_dev *pdev = priv->pdev;
126 	unsigned int num_probed = 0;
127 	char *name;
128 	int i;
129 
130 	for (i = 0; i < num_modules; i++) {
131 		name = modules[i];
132 		if (!strcmp(name, "") || !strcmp(name, "empty"))
133 			continue;
134 
135 		dev_dbg(&priv->pdev->dev, "MODULbus %d: name %s\n", i, name);
136 		cmodio_setup_subdevice(priv, name, num_probed, i);
137 		num_probed++;
138 	}
139 
140 	/* print an error message if no modules were probed */
141 	if (num_probed == 0) {
142 		dev_err(&priv->pdev->dev, "no MODULbus modules specified, "
143 					  "please set the ``modules'' kernel "
144 					  "parameter according to your "
145 					  "hardware configuration\n");
146 		return -ENODEV;
147 	}
148 
149 	return mfd_add_devices(&pdev->dev, 0, priv->cells,
150 			       num_probed, NULL, pdev->irq);
151 }
152 
153 /*
154  * SYSFS Attributes
155  */
156 
157 static ssize_t mbus_show(struct device *dev, struct device_attribute *attr,
158 			 char *buf)
159 {
160 	struct cmodio_device *priv = dev_get_drvdata(dev);
161 
162 	return snprintf(buf, PAGE_SIZE, "%x\n", priv->hex);
163 }
164 
165 static DEVICE_ATTR(modulbus_number, S_IRUGO, mbus_show, NULL);
166 
167 static struct attribute *cmodio_sysfs_attrs[] = {
168 	&dev_attr_modulbus_number.attr,
169 	NULL,
170 };
171 
172 static const struct attribute_group cmodio_sysfs_attr_group = {
173 	.attrs = cmodio_sysfs_attrs,
174 };
175 
176 /*
177  * PCI Driver
178  */
179 
180 static int __devinit cmodio_pci_probe(struct pci_dev *dev,
181 				      const struct pci_device_id *id)
182 {
183 	struct cmodio_device *priv;
184 	int ret;
185 
186 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
187 	if (!priv) {
188 		dev_err(&dev->dev, "unable to allocate private data\n");
189 		ret = -ENOMEM;
190 		goto out_return;
191 	}
192 
193 	pci_set_drvdata(dev, priv);
194 	priv->pdev = dev;
195 
196 	/* Hardware Initialization */
197 	ret = pci_enable_device(dev);
198 	if (ret) {
199 		dev_err(&dev->dev, "unable to enable device\n");
200 		goto out_free_priv;
201 	}
202 
203 	pci_set_master(dev);
204 	ret = pci_request_regions(dev, DRV_NAME);
205 	if (ret) {
206 		dev_err(&dev->dev, "unable to request regions\n");
207 		goto out_pci_disable_device;
208 	}
209 
210 	/* Onboard configuration registers */
211 	priv->ctrl = pci_ioremap_bar(dev, 4);
212 	if (!priv->ctrl) {
213 		dev_err(&dev->dev, "unable to remap onboard regs\n");
214 		ret = -ENOMEM;
215 		goto out_pci_release_regions;
216 	}
217 
218 	/* Read the hex switch on the carrier board */
219 	priv->hex = ioread8(&priv->ctrl->int_enable);
220 
221 	/* Add the MODULbus number (hex switch value) to the device's sysfs */
222 	ret = sysfs_create_group(&dev->dev.kobj, &cmodio_sysfs_attr_group);
223 	if (ret) {
224 		dev_err(&dev->dev, "unable to create sysfs attributes\n");
225 		goto out_unmap_ctrl;
226 	}
227 
228 	/*
229 	 * Disable all interrupt lines, each submodule will enable its
230 	 * own interrupt line if needed
231 	 */
232 	iowrite8(0xf, &priv->ctrl->int_disable);
233 
234 	/* Register drivers for all submodules */
235 	ret = cmodio_probe_submodules(priv);
236 	if (ret) {
237 		dev_err(&dev->dev, "unable to probe submodules\n");
238 		goto out_sysfs_remove_group;
239 	}
240 
241 	return 0;
242 
243 out_sysfs_remove_group:
244 	sysfs_remove_group(&dev->dev.kobj, &cmodio_sysfs_attr_group);
245 out_unmap_ctrl:
246 	iounmap(priv->ctrl);
247 out_pci_release_regions:
248 	pci_release_regions(dev);
249 out_pci_disable_device:
250 	pci_disable_device(dev);
251 out_free_priv:
252 	kfree(priv);
253 out_return:
254 	return ret;
255 }
256 
257 static void __devexit cmodio_pci_remove(struct pci_dev *dev)
258 {
259 	struct cmodio_device *priv = pci_get_drvdata(dev);
260 
261 	mfd_remove_devices(&dev->dev);
262 	sysfs_remove_group(&dev->dev.kobj, &cmodio_sysfs_attr_group);
263 	iounmap(priv->ctrl);
264 	pci_release_regions(dev);
265 	pci_disable_device(dev);
266 	kfree(priv);
267 }
268 
269 #define PCI_VENDOR_ID_JANZ		0x13c3
270 
271 /* The list of devices that this module will support */
272 static DEFINE_PCI_DEVICE_TABLE(cmodio_pci_ids) = {
273 	{ PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_JANZ, 0x0101 },
274 	{ PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050, PCI_VENDOR_ID_JANZ, 0x0100 },
275 	{ 0, }
276 };
277 MODULE_DEVICE_TABLE(pci, cmodio_pci_ids);
278 
279 static struct pci_driver cmodio_pci_driver = {
280 	.name     = DRV_NAME,
281 	.id_table = cmodio_pci_ids,
282 	.probe    = cmodio_pci_probe,
283 	.remove   = __devexit_p(cmodio_pci_remove),
284 };
285 
286 /*
287  * Module Init / Exit
288  */
289 
290 static int __init cmodio_init(void)
291 {
292 	return pci_register_driver(&cmodio_pci_driver);
293 }
294 
295 static void __exit cmodio_exit(void)
296 {
297 	pci_unregister_driver(&cmodio_pci_driver);
298 }
299 
300 MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
301 MODULE_DESCRIPTION("Janz CMOD-IO PCI MODULbus Carrier Board Driver");
302 MODULE_LICENSE("GPL");
303 
304 module_init(cmodio_init);
305 module_exit(cmodio_exit);
306