xref: /openbmc/linux/drivers/uio/uio_mf624.c (revision 65417d9f)
1 /*
2  * UIO driver fo Humusoft MF624 DAQ card.
3  * Copyright (C) 2011 Rostislav Lisovy <lisovy@gmail.com>,
4  *                    Czech Technical University in Prague
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 as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19  */
20 
21 #include <linux/init.h>
22 #include <linux/module.h>
23 #include <linux/device.h>
24 #include <linux/pci.h>
25 #include <linux/slab.h>
26 #include <linux/io.h>
27 #include <linux/kernel.h>
28 #include <linux/uio_driver.h>
29 
30 #define PCI_VENDOR_ID_HUMUSOFT		0x186c
31 #define PCI_DEVICE_ID_MF624		0x0624
32 #define PCI_SUBVENDOR_ID_HUMUSOFT	0x186c
33 #define PCI_SUBDEVICE_DEVICE		0x0624
34 
35 /* BAR0 Interrupt control/status register */
36 #define INTCSR				0x4C
37 #define INTCSR_ADINT_ENABLE		(1 << 0)
38 #define INTCSR_CTR4INT_ENABLE		(1 << 3)
39 #define INTCSR_PCIINT_ENABLE		(1 << 6)
40 #define INTCSR_ADINT_STATUS		(1 << 2)
41 #define INTCSR_CTR4INT_STATUS		(1 << 5)
42 
43 enum mf624_interrupt_source {ADC, CTR4, ALL};
44 
45 static void mf624_disable_interrupt(enum mf624_interrupt_source source,
46 			     struct uio_info *info)
47 {
48 	void __iomem *INTCSR_reg = info->mem[0].internal_addr + INTCSR;
49 
50 	switch (source) {
51 	case ADC:
52 		iowrite32(ioread32(INTCSR_reg)
53 			& ~(INTCSR_ADINT_ENABLE | INTCSR_PCIINT_ENABLE),
54 			INTCSR_reg);
55 		break;
56 
57 	case CTR4:
58 		iowrite32(ioread32(INTCSR_reg)
59 			& ~(INTCSR_CTR4INT_ENABLE | INTCSR_PCIINT_ENABLE),
60 			INTCSR_reg);
61 		break;
62 
63 	case ALL:
64 	default:
65 		iowrite32(ioread32(INTCSR_reg)
66 			& ~(INTCSR_ADINT_ENABLE | INTCSR_CTR4INT_ENABLE
67 			    | INTCSR_PCIINT_ENABLE),
68 			INTCSR_reg);
69 		break;
70 	}
71 }
72 
73 static void mf624_enable_interrupt(enum mf624_interrupt_source source,
74 			    struct uio_info *info)
75 {
76 	void __iomem *INTCSR_reg = info->mem[0].internal_addr + INTCSR;
77 
78 	switch (source) {
79 	case ADC:
80 		iowrite32(ioread32(INTCSR_reg)
81 			| INTCSR_ADINT_ENABLE | INTCSR_PCIINT_ENABLE,
82 			INTCSR_reg);
83 		break;
84 
85 	case CTR4:
86 		iowrite32(ioread32(INTCSR_reg)
87 			| INTCSR_CTR4INT_ENABLE | INTCSR_PCIINT_ENABLE,
88 			INTCSR_reg);
89 		break;
90 
91 	case ALL:
92 	default:
93 		iowrite32(ioread32(INTCSR_reg)
94 			| INTCSR_ADINT_ENABLE | INTCSR_CTR4INT_ENABLE
95 			| INTCSR_PCIINT_ENABLE,
96 			INTCSR_reg);
97 		break;
98 	}
99 }
100 
101 static irqreturn_t mf624_irq_handler(int irq, struct uio_info *info)
102 {
103 	void __iomem *INTCSR_reg = info->mem[0].internal_addr + INTCSR;
104 
105 	if ((ioread32(INTCSR_reg) & INTCSR_ADINT_ENABLE)
106 	    && (ioread32(INTCSR_reg) & INTCSR_ADINT_STATUS)) {
107 		mf624_disable_interrupt(ADC, info);
108 		return IRQ_HANDLED;
109 	}
110 
111 	if ((ioread32(INTCSR_reg) & INTCSR_CTR4INT_ENABLE)
112 	    && (ioread32(INTCSR_reg) & INTCSR_CTR4INT_STATUS)) {
113 		mf624_disable_interrupt(CTR4, info);
114 		return IRQ_HANDLED;
115 	}
116 
117 	return IRQ_NONE;
118 }
119 
120 static int mf624_irqcontrol(struct uio_info *info, s32 irq_on)
121 {
122 	if (irq_on == 0)
123 		mf624_disable_interrupt(ALL, info);
124 	else if (irq_on == 1)
125 		mf624_enable_interrupt(ALL, info);
126 
127 	return 0;
128 }
129 
130 static int mf624_setup_mem(struct pci_dev *dev, int bar, struct uio_mem *mem, const char *name)
131 {
132 	resource_size_t start = pci_resource_start(dev, bar);
133 	resource_size_t len = pci_resource_len(dev, bar);
134 
135 	mem->name = name;
136 	mem->addr = start & PAGE_MASK;
137 	mem->offs = start & ~PAGE_MASK;
138 	if (!mem->addr)
139 		return -ENODEV;
140 	mem->size = ((start & ~PAGE_MASK) + len + PAGE_SIZE - 1) & PAGE_MASK;
141 	mem->memtype = UIO_MEM_PHYS;
142 	mem->internal_addr = pci_ioremap_bar(dev, bar);
143 	if (!mem->internal_addr)
144 		return -ENODEV;
145 	return 0;
146 }
147 
148 static int mf624_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
149 {
150 	struct uio_info *info;
151 
152 	info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
153 	if (!info)
154 		return -ENOMEM;
155 
156 	if (pci_enable_device(dev))
157 		goto out_free;
158 
159 	if (pci_request_regions(dev, "mf624"))
160 		goto out_disable;
161 
162 	info->name = "mf624";
163 	info->version = "0.0.1";
164 
165 	/* Note: Datasheet says device uses BAR0, BAR1, BAR2 -- do not trust it */
166 
167 	/* BAR0 */
168 	if (mf624_setup_mem(dev, 0, &info->mem[0], "PCI chipset, interrupts, status "
169 			    "bits, special functions"))
170 		goto out_release;
171 	/* BAR2 */
172 	if (mf624_setup_mem(dev, 2, &info->mem[1], "ADC, DAC, DIO"))
173 		goto out_unmap0;
174 
175 	/* BAR4 */
176 	if (mf624_setup_mem(dev, 4, &info->mem[2], "Counter/timer chip"))
177 		goto out_unmap1;
178 
179 	info->irq = dev->irq;
180 	info->irq_flags = IRQF_SHARED;
181 	info->handler = mf624_irq_handler;
182 
183 	info->irqcontrol = mf624_irqcontrol;
184 
185 	if (uio_register_device(&dev->dev, info))
186 		goto out_unmap2;
187 
188 	pci_set_drvdata(dev, info);
189 
190 	return 0;
191 
192 out_unmap2:
193 	iounmap(info->mem[2].internal_addr);
194 out_unmap1:
195 	iounmap(info->mem[1].internal_addr);
196 out_unmap0:
197 	iounmap(info->mem[0].internal_addr);
198 
199 out_release:
200 	pci_release_regions(dev);
201 
202 out_disable:
203 	pci_disable_device(dev);
204 
205 out_free:
206 	kfree(info);
207 	return -ENODEV;
208 }
209 
210 static void mf624_pci_remove(struct pci_dev *dev)
211 {
212 	struct uio_info *info = pci_get_drvdata(dev);
213 
214 	mf624_disable_interrupt(ALL, info);
215 
216 	uio_unregister_device(info);
217 	pci_release_regions(dev);
218 	pci_disable_device(dev);
219 
220 	iounmap(info->mem[0].internal_addr);
221 	iounmap(info->mem[1].internal_addr);
222 	iounmap(info->mem[2].internal_addr);
223 
224 	kfree(info);
225 }
226 
227 static const struct pci_device_id mf624_pci_id[] = {
228 	{ PCI_DEVICE(PCI_VENDOR_ID_HUMUSOFT, PCI_DEVICE_ID_MF624) },
229 	{ 0, }
230 };
231 
232 static struct pci_driver mf624_pci_driver = {
233 	.name = "mf624",
234 	.id_table = mf624_pci_id,
235 	.probe = mf624_pci_probe,
236 	.remove = mf624_pci_remove,
237 };
238 MODULE_DEVICE_TABLE(pci, mf624_pci_id);
239 
240 module_pci_driver(mf624_pci_driver);
241 MODULE_LICENSE("GPL v2");
242 MODULE_AUTHOR("Rostislav Lisovy <lisovy@gmail.com>");
243