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authorLinus Torvalds <torvalds@linux-foundation.org>2010-10-28 18:54:04 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-28 18:54:04 -0400
commitb779b332d0e1ef68f40867948ae5526a3e925163 (patch)
treed2fc8bb455d696fbdb288055ce0a4f0cfcee31fd /drivers/gpio/vx855_gpio.c
parenta0cadc2777a71b1fde62e6417284b38e52128e88 (diff)
parent0f48285755991b73c14b6eeeee464590f490ac25 (diff)
Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-2.6
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-2.6: (73 commits) power: Revert "power_supply: Mark twl4030_charger as broken" mfd: Fix a memory leak when unload mc13xxx-core module mfd: Fix resource reclaim for max8998 mfd: Remove unneeded ret value checking for max8998 register updates mfd: Add free max8998->ono irq in max8998_irq_exit() mfd: Fix resource reclaim in pcf50633_remove() omap4: pandaboard: fix up mmc card detect logic mfd: Fix ezx_pcap_probe error path mfd: Fix off-by-one value range checking for tps6507x mfd: Remove __devinitdata from tc6393xb_mmc_resources mfd: Add WM831x SPI support mfd: Factor out WM831x I2C I/O from the core driver mfd: Remove DEBUG defines from mc13xxx-core mfd: Fix jz4740_adc_set_enabled mfd: Add TPS658621C device ID mfd: Fix twl-irq function declaration warnings regulator: max8998 BUCK1/2 voltage change with use of GPIOs mfd: Voltages and GPIOs platform_data definitions for max8998 regulator: max8998 BUCK1/2 internal voltages and indexes defined mfd: Support for ICs compliant with max8998 ...
Diffstat (limited to 'drivers/gpio/vx855_gpio.c')
-rw-r--r--drivers/gpio/vx855_gpio.c332
1 files changed, 332 insertions, 0 deletions
diff --git a/drivers/gpio/vx855_gpio.c b/drivers/gpio/vx855_gpio.c
new file mode 100644
index 000000000000..8a98ee5d5f6c
--- /dev/null
+++ b/drivers/gpio/vx855_gpio.c
@@ -0,0 +1,332 @@
1/*
2 * Linux GPIOlib driver for the VIA VX855 integrated southbridge GPIO
3 *
4 * Copyright (C) 2009 VIA Technologies, Inc.
5 * Copyright (C) 2010 One Laptop per Child
6 * Author: Harald Welte <HaraldWelte@viatech.com>
7 * All rights reserved.
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation; either version 2 of
12 * the License, or (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
22 * MA 02111-1307 USA
23 *
24 */
25
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/gpio.h>
29#include <linux/device.h>
30#include <linux/platform_device.h>
31#include <linux/pci.h>
32#include <linux/io.h>
33
34#define MODULE_NAME "vx855_gpio"
35
36/* The VX855 south bridge has the following GPIO pins:
37 * GPI 0...13 General Purpose Input
38 * GPO 0...12 General Purpose Output
39 * GPIO 0...14 General Purpose I/O (Open-Drain)
40 */
41
42#define NR_VX855_GPI 14
43#define NR_VX855_GPO 13
44#define NR_VX855_GPIO 15
45
46#define NR_VX855_GPInO (NR_VX855_GPI + NR_VX855_GPO)
47#define NR_VX855_GP (NR_VX855_GPI + NR_VX855_GPO + NR_VX855_GPIO)
48
49struct vx855_gpio {
50 struct gpio_chip gpio;
51 spinlock_t lock;
52 u32 io_gpi;
53 u32 io_gpo;
54 bool gpi_reserved;
55 bool gpo_reserved;
56};
57
58/* resolve a GPIx into the corresponding bit position */
59static inline u_int32_t gpi_i_bit(int i)
60{
61 if (i < 10)
62 return 1 << i;
63 else
64 return 1 << (i + 14);
65}
66
67static inline u_int32_t gpo_o_bit(int i)
68{
69 if (i < 11)
70 return 1 << i;
71 else
72 return 1 << (i + 14);
73}
74
75static inline u_int32_t gpio_i_bit(int i)
76{
77 if (i < 14)
78 return 1 << (i + 10);
79 else
80 return 1 << (i + 14);
81}
82
83static inline u_int32_t gpio_o_bit(int i)
84{
85 if (i < 14)
86 return 1 << (i + 11);
87 else
88 return 1 << (i + 13);
89}
90
91/* Mapping betwee numeric GPIO ID and the actual GPIO hardware numbering:
92 * 0..13 GPI 0..13
93 * 14..26 GPO 0..12
94 * 27..41 GPIO 0..14
95 */
96
97static int vx855gpio_direction_input(struct gpio_chip *gpio,
98 unsigned int nr)
99{
100 struct vx855_gpio *vg = container_of(gpio, struct vx855_gpio, gpio);
101 unsigned long flags;
102 u_int32_t reg_out;
103
104 /* Real GPI bits are always in input direction */
105 if (nr < NR_VX855_GPI)
106 return 0;
107
108 /* Real GPO bits cannot be put in output direction */
109 if (nr < NR_VX855_GPInO)
110 return -EINVAL;
111
112 /* Open Drain GPIO have to be set to one */
113 spin_lock_irqsave(&vg->lock, flags);
114 reg_out = inl(vg->io_gpo);
115 reg_out |= gpio_o_bit(nr - NR_VX855_GPInO);
116 outl(reg_out, vg->io_gpo);
117 spin_unlock_irqrestore(&vg->lock, flags);
118
119 return 0;
120}
121
122static int vx855gpio_get(struct gpio_chip *gpio, unsigned int nr)
123{
124 struct vx855_gpio *vg = container_of(gpio, struct vx855_gpio, gpio);
125 u_int32_t reg_in;
126 int ret = 0;
127
128 if (nr < NR_VX855_GPI) {
129 reg_in = inl(vg->io_gpi);
130 if (reg_in & gpi_i_bit(nr))
131 ret = 1;
132 } else if (nr < NR_VX855_GPInO) {
133 /* GPO don't have an input bit, we need to read it
134 * back from the output register */
135 reg_in = inl(vg->io_gpo);
136 if (reg_in & gpo_o_bit(nr - NR_VX855_GPI))
137 ret = 1;
138 } else {
139 reg_in = inl(vg->io_gpi);
140 if (reg_in & gpio_i_bit(nr - NR_VX855_GPInO))
141 ret = 1;
142 }
143
144 return ret;
145}
146
147static void vx855gpio_set(struct gpio_chip *gpio, unsigned int nr,
148 int val)
149{
150 struct vx855_gpio *vg = container_of(gpio, struct vx855_gpio, gpio);
151 unsigned long flags;
152 u_int32_t reg_out;
153
154 /* True GPI cannot be switched to output mode */
155 if (nr < NR_VX855_GPI)
156 return;
157
158 spin_lock_irqsave(&vg->lock, flags);
159 reg_out = inl(vg->io_gpo);
160 if (nr < NR_VX855_GPInO) {
161 if (val)
162 reg_out |= gpo_o_bit(nr - NR_VX855_GPI);
163 else
164 reg_out &= ~gpo_o_bit(nr - NR_VX855_GPI);
165 } else {
166 if (val)
167 reg_out |= gpio_o_bit(nr - NR_VX855_GPInO);
168 else
169 reg_out &= ~gpio_o_bit(nr - NR_VX855_GPInO);
170 }
171 outl(reg_out, vg->io_gpo);
172 spin_unlock_irqrestore(&vg->lock, flags);
173}
174
175static int vx855gpio_direction_output(struct gpio_chip *gpio,
176 unsigned int nr, int val)
177{
178 /* True GPI cannot be switched to output mode */
179 if (nr < NR_VX855_GPI)
180 return -EINVAL;
181
182 /* True GPO don't need to be switched to output mode,
183 * and GPIO are open-drain, i.e. also need no switching,
184 * so all we do is set the level */
185 vx855gpio_set(gpio, nr, val);
186
187 return 0;
188}
189
190static const char *vx855gpio_names[NR_VX855_GP] = {
191 "VX855_GPI0", "VX855_GPI1", "VX855_GPI2", "VX855_GPI3", "VX855_GPI4",
192 "VX855_GPI5", "VX855_GPI6", "VX855_GPI7", "VX855_GPI8", "VX855_GPI9",
193 "VX855_GPI10", "VX855_GPI11", "VX855_GPI12", "VX855_GPI13",
194 "VX855_GPO0", "VX855_GPO1", "VX855_GPO2", "VX855_GPO3", "VX855_GPO4",
195 "VX855_GPO5", "VX855_GPO6", "VX855_GPO7", "VX855_GPO8", "VX855_GPO9",
196 "VX855_GPO10", "VX855_GPO11", "VX855_GPO12",
197 "VX855_GPIO0", "VX855_GPIO1", "VX855_GPIO2", "VX855_GPIO3",
198 "VX855_GPIO4", "VX855_GPIO5", "VX855_GPIO6", "VX855_GPIO7",
199 "VX855_GPIO8", "VX855_GPIO9", "VX855_GPIO10", "VX855_GPIO11",
200 "VX855_GPIO12", "VX855_GPIO13", "VX855_GPIO14"
201};
202
203static void vx855gpio_gpio_setup(struct vx855_gpio *vg)
204{
205 struct gpio_chip *c = &vg->gpio;
206
207 c->label = "VX855 South Bridge";
208 c->owner = THIS_MODULE;
209 c->direction_input = vx855gpio_direction_input;
210 c->direction_output = vx855gpio_direction_output;
211 c->get = vx855gpio_get;
212 c->set = vx855gpio_set;
213 c->dbg_show = NULL;
214 c->base = 0;
215 c->ngpio = NR_VX855_GP;
216 c->can_sleep = 0;
217 c->names = vx855gpio_names;
218}
219
220/* This platform device is ordinarily registered by the vx855 mfd driver */
221static __devinit int vx855gpio_probe(struct platform_device *pdev)
222{
223 struct resource *res_gpi;
224 struct resource *res_gpo;
225 struct vx855_gpio *vg;
226 int ret;
227
228 res_gpi = platform_get_resource(pdev, IORESOURCE_IO, 0);
229 res_gpo = platform_get_resource(pdev, IORESOURCE_IO, 1);
230 if (!res_gpi || !res_gpo)
231 return -EBUSY;
232
233 vg = kzalloc(sizeof(*vg), GFP_KERNEL);
234 if (!vg)
235 return -ENOMEM;
236
237 platform_set_drvdata(pdev, vg);
238
239 dev_info(&pdev->dev, "found VX855 GPIO controller\n");
240 vg->io_gpi = res_gpi->start;
241 vg->io_gpo = res_gpo->start;
242 spin_lock_init(&vg->lock);
243
244 /*
245 * A single byte is used to control various GPIO ports on the VX855,
246 * and in the case of the OLPC XO-1.5, some of those ports are used
247 * for switches that are interpreted and exposed through ACPI. ACPI
248 * will have reserved the region, so our own reservation will not
249 * succeed. Ignore and continue.
250 */
251
252 if (!request_region(res_gpi->start, resource_size(res_gpi),
253 MODULE_NAME "_gpi"))
254 dev_warn(&pdev->dev,
255 "GPI I/O resource busy, probably claimed by ACPI\n");
256 else
257 vg->gpi_reserved = true;
258
259 if (!request_region(res_gpo->start, resource_size(res_gpo),
260 MODULE_NAME "_gpo"))
261 dev_warn(&pdev->dev,
262 "GPO I/O resource busy, probably claimed by ACPI\n");
263 else
264 vg->gpo_reserved = true;
265
266 vx855gpio_gpio_setup(vg);
267
268 ret = gpiochip_add(&vg->gpio);
269 if (ret) {
270 dev_err(&pdev->dev, "failed to register GPIOs\n");
271 goto out_release;
272 }
273
274 return 0;
275
276out_release:
277 if (vg->gpi_reserved)
278 release_region(res_gpi->start, resource_size(res_gpi));
279 if (vg->gpo_reserved)
280 release_region(res_gpi->start, resource_size(res_gpo));
281 platform_set_drvdata(pdev, NULL);
282 kfree(vg);
283 return ret;
284}
285
286static int __devexit vx855gpio_remove(struct platform_device *pdev)
287{
288 struct vx855_gpio *vg = platform_get_drvdata(pdev);
289 struct resource *res;
290
291 if (gpiochip_remove(&vg->gpio))
292 dev_err(&pdev->dev, "unable to remove gpio_chip?\n");
293
294 if (vg->gpi_reserved) {
295 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
296 release_region(res->start, resource_size(res));
297 }
298 if (vg->gpo_reserved) {
299 res = platform_get_resource(pdev, IORESOURCE_IO, 1);
300 release_region(res->start, resource_size(res));
301 }
302
303 platform_set_drvdata(pdev, NULL);
304 kfree(vg);
305 return 0;
306}
307
308static struct platform_driver vx855gpio_driver = {
309 .driver = {
310 .name = MODULE_NAME,
311 .owner = THIS_MODULE,
312 },
313 .probe = vx855gpio_probe,
314 .remove = __devexit_p(vx855gpio_remove),
315};
316
317static int vx855gpio_init(void)
318{
319 return platform_driver_register(&vx855gpio_driver);
320}
321module_init(vx855gpio_init);
322
323static void vx855gpio_exit(void)
324{
325 platform_driver_unregister(&vx855gpio_driver);
326}
327module_exit(vx855gpio_exit);
328
329MODULE_LICENSE("GPL");
330MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
331MODULE_DESCRIPTION("GPIO driver for the VIA VX855 chipset");
332MODULE_ALIAS("platform:vx855_gpio");