xref: /openbmc/linux/drivers/mfd/janz-cmodio.c (revision 25b892b5)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Janz CMOD-IO MODULbus Carrier Board PCI Driver
4  *
5  * Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu>
6  *
7  * Lots of inspiration and code was copied from drivers/mfd/sm501.c
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/pci.h>
13 #include <linux/interrupt.h>
14 #include <linux/delay.h>
15 #include <linux/platform_device.h>
16 #include <linux/slab.h>
17 #include <linux/mfd/core.h>
18 
19 #include <linux/mfd/janz.h>
20 
21 #define DRV_NAME "janz-cmodio"
22 
23 /* Size of each MODULbus module in PCI BAR4 */
24 #define CMODIO_MODULBUS_SIZE	0x200
25 
26 /* Maximum number of MODULbus modules on a CMOD-IO carrier board */
27 #define CMODIO_MAX_MODULES	4
28 
29 /* Module Parameters */
30 static unsigned int num_modules = CMODIO_MAX_MODULES;
31 static char *modules[CMODIO_MAX_MODULES] = {
32 	"empty", "empty", "empty", "empty",
33 };
34 
35 module_param_array(modules, charp, &num_modules, S_IRUGO);
36 MODULE_PARM_DESC(modules, "MODULbus modules attached to the carrier board");
37 
38 /* Unique Device Id */
39 static unsigned int cmodio_id;
40 
41 struct cmodio_device {
42 	/* Parent PCI device */
43 	struct pci_dev *pdev;
44 
45 	/* PLX control registers */
46 	struct janz_cmodio_onboard_regs __iomem *ctrl;
47 
48 	/* hex switch position */
49 	u8 hex;
50 
51 	/* mfd-core API */
52 	struct mfd_cell cells[CMODIO_MAX_MODULES];
53 	struct resource resources[3 * CMODIO_MAX_MODULES];
54 	struct janz_platform_data pdata[CMODIO_MAX_MODULES];
55 };
56 
57 /*
58  * Subdevices using the mfd-core API
59  */
60 
61 static int cmodio_setup_subdevice(struct cmodio_device *priv,
62 					    char *name, unsigned int devno,
63 					    unsigned int modno)
64 {
65 	struct janz_platform_data *pdata;
66 	struct mfd_cell *cell;
67 	struct resource *res;
68 	struct pci_dev *pci;
69 
70 	pci = priv->pdev;
71 	cell = &priv->cells[devno];
72 	res = &priv->resources[devno * 3];
73 	pdata = &priv->pdata[devno];
74 
75 	cell->name = name;
76 	cell->resources = res;
77 	cell->num_resources = 3;
78 
79 	/* Setup the subdevice ID -- must be unique */
80 	cell->id = cmodio_id++;
81 
82 	/* Add platform data */
83 	pdata->modno = modno;
84 	cell->platform_data = pdata;
85 	cell->pdata_size = sizeof(*pdata);
86 
87 	/* MODULbus registers -- PCI BAR3 is big-endian MODULbus access */
88 	res->flags = IORESOURCE_MEM;
89 	res->parent = &pci->resource[3];
90 	res->start = pci->resource[3].start + (CMODIO_MODULBUS_SIZE * modno);
91 	res->end = res->start + CMODIO_MODULBUS_SIZE - 1;
92 	res++;
93 
94 	/* PLX Control Registers -- PCI BAR4 is interrupt and other registers */
95 	res->flags = IORESOURCE_MEM;
96 	res->parent = &pci->resource[4];
97 	res->start = pci->resource[4].start;
98 	res->end = pci->resource[4].end;
99 	res++;
100 
101 	/*
102 	 * IRQ
103 	 *
104 	 * The start and end fields are used as an offset to the irq_base
105 	 * parameter passed into the mfd_add_devices() function call. All
106 	 * devices share the same IRQ.
107 	 */
108 	res->flags = IORESOURCE_IRQ;
109 	res->parent = NULL;
110 	res->start = 0;
111 	res->end = 0;
112 	res++;
113 
114 	return 0;
115 }
116 
117 /* Probe each submodule using kernel parameters */
118 static int cmodio_probe_submodules(struct cmodio_device *priv)
119 {
120 	struct pci_dev *pdev = priv->pdev;
121 	unsigned int num_probed = 0;
122 	char *name;
123 	int i;
124 
125 	for (i = 0; i < num_modules; i++) {
126 		name = modules[i];
127 		if (!strcmp(name, "") || !strcmp(name, "empty"))
128 			continue;
129 
130 		dev_dbg(&priv->pdev->dev, "MODULbus %d: name %s\n", i, name);
131 		cmodio_setup_subdevice(priv, name, num_probed, i);
132 		num_probed++;
133 	}
134 
135 	/* print an error message if no modules were probed */
136 	if (num_probed == 0) {
137 		dev_err(&priv->pdev->dev, "no MODULbus modules specified, "
138 					  "please set the ``modules'' kernel "
139 					  "parameter according to your "
140 					  "hardware configuration\n");
141 		return -ENODEV;
142 	}
143 
144 	return mfd_add_devices(&pdev->dev, 0, priv->cells,
145 			       num_probed, NULL, pdev->irq, NULL);
146 }
147 
148 /*
149  * SYSFS Attributes
150  */
151 
152 static ssize_t modulbus_number_show(struct device *dev,
153 				    struct device_attribute *attr, char *buf)
154 {
155 	struct cmodio_device *priv = dev_get_drvdata(dev);
156 
157 	return snprintf(buf, PAGE_SIZE, "%x\n", priv->hex);
158 }
159 
160 static DEVICE_ATTR_RO(modulbus_number);
161 
162 static struct attribute *cmodio_sysfs_attrs[] = {
163 	&dev_attr_modulbus_number.attr,
164 	NULL,
165 };
166 
167 static const struct attribute_group cmodio_sysfs_attr_group = {
168 	.attrs = cmodio_sysfs_attrs,
169 };
170 
171 /*
172  * PCI Driver
173  */
174 
175 static int cmodio_pci_probe(struct pci_dev *dev,
176 				      const struct pci_device_id *id)
177 {
178 	struct cmodio_device *priv;
179 	int ret;
180 
181 	priv = devm_kzalloc(&dev->dev, sizeof(*priv), GFP_KERNEL);
182 	if (!priv)
183 		return -ENOMEM;
184 
185 	pci_set_drvdata(dev, priv);
186 	priv->pdev = dev;
187 
188 	/* Hardware Initialization */
189 	ret = pci_enable_device(dev);
190 	if (ret) {
191 		dev_err(&dev->dev, "unable to enable device\n");
192 		return ret;
193 	}
194 
195 	pci_set_master(dev);
196 	ret = pci_request_regions(dev, DRV_NAME);
197 	if (ret) {
198 		dev_err(&dev->dev, "unable to request regions\n");
199 		goto out_pci_disable_device;
200 	}
201 
202 	/* Onboard configuration registers */
203 	priv->ctrl = pci_ioremap_bar(dev, 4);
204 	if (!priv->ctrl) {
205 		dev_err(&dev->dev, "unable to remap onboard regs\n");
206 		ret = -ENOMEM;
207 		goto out_pci_release_regions;
208 	}
209 
210 	/* Read the hex switch on the carrier board */
211 	priv->hex = ioread8(&priv->ctrl->int_enable);
212 
213 	/* Add the MODULbus number (hex switch value) to the device's sysfs */
214 	ret = sysfs_create_group(&dev->dev.kobj, &cmodio_sysfs_attr_group);
215 	if (ret) {
216 		dev_err(&dev->dev, "unable to create sysfs attributes\n");
217 		goto out_unmap_ctrl;
218 	}
219 
220 	/*
221 	 * Disable all interrupt lines, each submodule will enable its
222 	 * own interrupt line if needed
223 	 */
224 	iowrite8(0xf, &priv->ctrl->int_disable);
225 
226 	/* Register drivers for all submodules */
227 	ret = cmodio_probe_submodules(priv);
228 	if (ret) {
229 		dev_err(&dev->dev, "unable to probe submodules\n");
230 		goto out_sysfs_remove_group;
231 	}
232 
233 	return 0;
234 
235 out_sysfs_remove_group:
236 	sysfs_remove_group(&dev->dev.kobj, &cmodio_sysfs_attr_group);
237 out_unmap_ctrl:
238 	iounmap(priv->ctrl);
239 out_pci_release_regions:
240 	pci_release_regions(dev);
241 out_pci_disable_device:
242 	pci_disable_device(dev);
243 
244 	return ret;
245 }
246 
247 static void cmodio_pci_remove(struct pci_dev *dev)
248 {
249 	struct cmodio_device *priv = pci_get_drvdata(dev);
250 
251 	mfd_remove_devices(&dev->dev);
252 	sysfs_remove_group(&dev->dev.kobj, &cmodio_sysfs_attr_group);
253 	iounmap(priv->ctrl);
254 	pci_release_regions(dev);
255 	pci_disable_device(dev);
256 }
257 
258 #define PCI_VENDOR_ID_JANZ		0x13c3
259 
260 /* The list of devices that this module will support */
261 static const struct pci_device_id cmodio_pci_ids[] = {
262 	{ PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_JANZ, 0x0101 },
263 	{ PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050, PCI_VENDOR_ID_JANZ, 0x0100 },
264 	{ PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_JANZ, 0x0201 },
265 	{ PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_JANZ, 0x0202 },
266 	{ PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050, PCI_VENDOR_ID_JANZ, 0x0201 },
267 	{ PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050, PCI_VENDOR_ID_JANZ, 0x0202 },
268 	{ 0, }
269 };
270 MODULE_DEVICE_TABLE(pci, cmodio_pci_ids);
271 
272 static struct pci_driver cmodio_pci_driver = {
273 	.name     = DRV_NAME,
274 	.id_table = cmodio_pci_ids,
275 	.probe    = cmodio_pci_probe,
276 	.remove   = cmodio_pci_remove,
277 };
278 
279 module_pci_driver(cmodio_pci_driver);
280 
281 MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
282 MODULE_DESCRIPTION("Janz CMOD-IO PCI MODULbus Carrier Board Driver");
283 MODULE_LICENSE("GPL");
284