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1 | /* |
2 | * Janz MODULbus VMOD-TTL GPIO Driver | |
3 | * | |
4 | * Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License as published by the | |
8 | * Free Software Foundation; either version 2 of the License, or (at your | |
9 | * option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/interrupt.h> | |
16 | #include <linux/delay.h> | |
17 | #include <linux/platform_device.h> | |
8615e4cb | 18 | #include <linux/mfd/core.h> |
800e69fb IS |
19 | #include <linux/io.h> |
20 | #include <linux/gpio.h> | |
21 | #include <linux/slab.h> | |
22 | ||
23 | #include <linux/mfd/janz.h> | |
24 | ||
25 | #define DRV_NAME "janz-ttl" | |
26 | ||
27 | #define PORTA_DIRECTION 0x23 | |
28 | #define PORTB_DIRECTION 0x2B | |
29 | #define PORTC_DIRECTION 0x06 | |
30 | #define PORTA_IOCTL 0x24 | |
31 | #define PORTB_IOCTL 0x2C | |
32 | #define PORTC_IOCTL 0x07 | |
33 | ||
34 | #define MASTER_INT_CTL 0x00 | |
35 | #define MASTER_CONF_CTL 0x01 | |
36 | ||
37 | #define CONF_PAE (1 << 2) | |
38 | #define CONF_PBE (1 << 7) | |
39 | #define CONF_PCE (1 << 4) | |
40 | ||
41 | struct ttl_control_regs { | |
42 | __be16 portc; | |
43 | __be16 portb; | |
44 | __be16 porta; | |
45 | __be16 control; | |
46 | }; | |
47 | ||
48 | struct ttl_module { | |
49 | struct gpio_chip gpio; | |
50 | ||
51 | /* base address of registers */ | |
52 | struct ttl_control_regs __iomem *regs; | |
53 | ||
54 | u8 portc_shadow; | |
55 | u8 portb_shadow; | |
56 | u8 porta_shadow; | |
57 | ||
58 | spinlock_t lock; | |
59 | }; | |
60 | ||
61 | static int ttl_get_value(struct gpio_chip *gpio, unsigned offset) | |
62 | { | |
63 | struct ttl_module *mod = dev_get_drvdata(gpio->dev); | |
64 | u8 *shadow; | |
65 | int ret; | |
66 | ||
67 | if (offset < 8) { | |
68 | shadow = &mod->porta_shadow; | |
69 | } else if (offset < 16) { | |
70 | shadow = &mod->portb_shadow; | |
71 | offset -= 8; | |
72 | } else { | |
73 | shadow = &mod->portc_shadow; | |
74 | offset -= 16; | |
75 | } | |
76 | ||
77 | spin_lock(&mod->lock); | |
78 | ret = *shadow & (1 << offset); | |
79 | spin_unlock(&mod->lock); | |
80 | return ret; | |
81 | } | |
82 | ||
83 | static void ttl_set_value(struct gpio_chip *gpio, unsigned offset, int value) | |
84 | { | |
85 | struct ttl_module *mod = dev_get_drvdata(gpio->dev); | |
86 | void __iomem *port; | |
87 | u8 *shadow; | |
88 | ||
89 | if (offset < 8) { | |
90 | port = &mod->regs->porta; | |
91 | shadow = &mod->porta_shadow; | |
92 | } else if (offset < 16) { | |
93 | port = &mod->regs->portb; | |
94 | shadow = &mod->portb_shadow; | |
95 | offset -= 8; | |
96 | } else { | |
97 | port = &mod->regs->portc; | |
98 | shadow = &mod->portc_shadow; | |
99 | offset -= 16; | |
100 | } | |
101 | ||
102 | spin_lock(&mod->lock); | |
103 | if (value) | |
104 | *shadow |= (1 << offset); | |
105 | else | |
106 | *shadow &= ~(1 << offset); | |
107 | ||
108 | iowrite16be(*shadow, port); | |
109 | spin_unlock(&mod->lock); | |
110 | } | |
111 | ||
112 | static void __devinit ttl_write_reg(struct ttl_module *mod, u8 reg, u16 val) | |
113 | { | |
114 | iowrite16be(reg, &mod->regs->control); | |
115 | iowrite16be(val, &mod->regs->control); | |
116 | } | |
117 | ||
118 | static void __devinit ttl_setup_device(struct ttl_module *mod) | |
119 | { | |
120 | /* reset the device to a known state */ | |
121 | iowrite16be(0x0000, &mod->regs->control); | |
122 | iowrite16be(0x0001, &mod->regs->control); | |
123 | iowrite16be(0x0000, &mod->regs->control); | |
124 | ||
125 | /* put all ports in open-drain mode */ | |
126 | ttl_write_reg(mod, PORTA_IOCTL, 0x00ff); | |
127 | ttl_write_reg(mod, PORTB_IOCTL, 0x00ff); | |
128 | ttl_write_reg(mod, PORTC_IOCTL, 0x000f); | |
129 | ||
130 | /* set all ports as outputs */ | |
131 | ttl_write_reg(mod, PORTA_DIRECTION, 0x0000); | |
132 | ttl_write_reg(mod, PORTB_DIRECTION, 0x0000); | |
133 | ttl_write_reg(mod, PORTC_DIRECTION, 0x0000); | |
134 | ||
135 | /* set all ports to drive zeroes */ | |
136 | iowrite16be(0x0000, &mod->regs->porta); | |
137 | iowrite16be(0x0000, &mod->regs->portb); | |
138 | iowrite16be(0x0000, &mod->regs->portc); | |
139 | ||
140 | /* enable all ports */ | |
141 | ttl_write_reg(mod, MASTER_CONF_CTL, CONF_PAE | CONF_PBE | CONF_PCE); | |
142 | } | |
143 | ||
144 | static int __devinit ttl_probe(struct platform_device *pdev) | |
145 | { | |
146 | struct janz_platform_data *pdata; | |
147 | struct device *dev = &pdev->dev; | |
148 | struct ttl_module *mod; | |
149 | struct gpio_chip *gpio; | |
150 | struct resource *res; | |
151 | int ret; | |
152 | ||
8615e4cb | 153 | pdata = mfd_get_data(pdev); |
800e69fb IS |
154 | if (!pdata) { |
155 | dev_err(dev, "no platform data\n"); | |
156 | ret = -ENXIO; | |
157 | goto out_return; | |
158 | } | |
159 | ||
160 | mod = kzalloc(sizeof(*mod), GFP_KERNEL); | |
161 | if (!mod) { | |
162 | dev_err(dev, "unable to allocate private data\n"); | |
163 | ret = -ENOMEM; | |
164 | goto out_return; | |
165 | } | |
166 | ||
167 | platform_set_drvdata(pdev, mod); | |
168 | spin_lock_init(&mod->lock); | |
169 | ||
170 | /* get access to the MODULbus registers for this module */ | |
171 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
172 | if (!res) { | |
173 | dev_err(dev, "MODULbus registers not found\n"); | |
174 | ret = -ENODEV; | |
175 | goto out_free_mod; | |
176 | } | |
177 | ||
178 | mod->regs = ioremap(res->start, resource_size(res)); | |
179 | if (!mod->regs) { | |
180 | dev_err(dev, "MODULbus registers not ioremap\n"); | |
181 | ret = -ENOMEM; | |
182 | goto out_free_mod; | |
183 | } | |
184 | ||
185 | ttl_setup_device(mod); | |
186 | ||
187 | /* Initialize the GPIO data structures */ | |
188 | gpio = &mod->gpio; | |
189 | gpio->dev = &pdev->dev; | |
190 | gpio->label = pdev->name; | |
191 | gpio->get = ttl_get_value; | |
192 | gpio->set = ttl_set_value; | |
193 | gpio->owner = THIS_MODULE; | |
194 | ||
195 | /* request dynamic allocation */ | |
196 | gpio->base = -1; | |
197 | gpio->ngpio = 20; | |
198 | ||
199 | ret = gpiochip_add(gpio); | |
200 | if (ret) { | |
201 | dev_err(dev, "unable to add GPIO chip\n"); | |
202 | goto out_iounmap_regs; | |
203 | } | |
204 | ||
205 | dev_info(&pdev->dev, "module %d: registered GPIO device\n", | |
206 | pdata->modno); | |
207 | return 0; | |
208 | ||
209 | out_iounmap_regs: | |
210 | iounmap(mod->regs); | |
211 | out_free_mod: | |
212 | kfree(mod); | |
213 | out_return: | |
214 | return ret; | |
215 | } | |
216 | ||
217 | static int __devexit ttl_remove(struct platform_device *pdev) | |
218 | { | |
219 | struct ttl_module *mod = platform_get_drvdata(pdev); | |
220 | struct device *dev = &pdev->dev; | |
221 | int ret; | |
222 | ||
223 | ret = gpiochip_remove(&mod->gpio); | |
224 | if (ret) { | |
225 | dev_err(dev, "unable to remove GPIO chip\n"); | |
226 | return ret; | |
227 | } | |
228 | ||
229 | iounmap(mod->regs); | |
230 | kfree(mod); | |
231 | return 0; | |
232 | } | |
233 | ||
234 | static struct platform_driver ttl_driver = { | |
235 | .driver = { | |
236 | .name = DRV_NAME, | |
237 | .owner = THIS_MODULE, | |
238 | }, | |
239 | .probe = ttl_probe, | |
240 | .remove = __devexit_p(ttl_remove), | |
241 | }; | |
242 | ||
243 | static int __init ttl_init(void) | |
244 | { | |
245 | return platform_driver_register(&ttl_driver); | |
246 | } | |
247 | ||
248 | static void __exit ttl_exit(void) | |
249 | { | |
250 | platform_driver_unregister(&ttl_driver); | |
251 | } | |
252 | ||
253 | MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>"); | |
254 | MODULE_DESCRIPTION("Janz MODULbus VMOD-TTL Driver"); | |
255 | MODULE_LICENSE("GPL"); | |
256 | MODULE_ALIAS("platform:janz-ttl"); | |
257 | ||
258 | module_init(ttl_init); | |
259 | module_exit(ttl_exit); |