1/*
2 * Retu/Tahvo MFD driver
3 *
4 * Copyright (C) 2004, 2005 Nokia Corporation
5 *
6 * Based on code written by Juha Yrjölä, David Weinehall and Mikko Ylinen.
7 * Rewritten by Aaro Koskinen.
8 *
9 * This file is subject to the terms and conditions of the GNU General
10 * Public License. See the file "COPYING" in the main directory of this
11 * archive for more details.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 */
18
19#include <linux/err.h>
20#include <linux/i2c.h>
21#include <linux/irq.h>
22#include <linux/slab.h>
23#include <linux/mutex.h>
24#include <linux/module.h>
25#include <linux/regmap.h>
26#include <linux/mfd/core.h>
27#include <linux/mfd/retu.h>
28#include <linux/interrupt.h>
29#include <linux/moduleparam.h>
30
31/* Registers */
32#define RETU_REG_ASICR 0x00 /* ASIC ID and revision */
33#define RETU_REG_ASICR_VILMA (1 << 7) /* Bit indicating Vilma */
34#define RETU_REG_IDR 0x01 /* Interrupt ID */
35#define RETU_REG_IMR 0x02 /* Interrupt mask (Retu) */
36#define TAHVO_REG_IMR 0x03 /* Interrupt mask (Tahvo) */
37
38/* Interrupt sources */
39#define RETU_INT_PWR 0 /* Power button */
40
41struct retu_dev {
42 struct regmap *regmap;
43 struct device *dev;
44 struct mutex mutex;
45 struct regmap_irq_chip_data *irq_data;
46};
47
48static struct resource retu_pwrbutton_res[] = {
49 {
50 .name = "retu-pwrbutton",
51 .start = RETU_INT_PWR,
52 .end = RETU_INT_PWR,
53 .flags = IORESOURCE_IRQ,
54 },
55};
56
57static const struct mfd_cell retu_devs[] = {
58 {
59 .name = "retu-wdt"
60 },
61 {
62 .name = "retu-pwrbutton",
63 .resources = retu_pwrbutton_res,
64 .num_resources = ARRAY_SIZE(retu_pwrbutton_res),
65 }
66};
67
68static struct regmap_irq retu_irqs[] = {
69 [RETU_INT_PWR] = {
70 .mask = 1 << RETU_INT_PWR,
71 }
72};
73
74static struct regmap_irq_chip retu_irq_chip = {
75 .name = "RETU",
76 .irqs = retu_irqs,
77 .num_irqs = ARRAY_SIZE(retu_irqs),
78 .num_regs = 1,
79 .status_base = RETU_REG_IDR,
80 .mask_base = RETU_REG_IMR,
81 .ack_base = RETU_REG_IDR,
82};
83
84/* Retu device registered for the power off. */
85static struct retu_dev *retu_pm_power_off;
86
87static struct resource tahvo_usb_res[] = {
88 {
89 .name = "tahvo-usb",
90 .start = TAHVO_INT_VBUS,
91 .end = TAHVO_INT_VBUS,
92 .flags = IORESOURCE_IRQ,
93 },
94};
95
96static const struct mfd_cell tahvo_devs[] = {
97 {
98 .name = "tahvo-usb",
99 .resources = tahvo_usb_res,
100 .num_resources = ARRAY_SIZE(tahvo_usb_res),
101 },
102};
103
104static struct regmap_irq tahvo_irqs[] = {
105 [TAHVO_INT_VBUS] = {
106 .mask = 1 << TAHVO_INT_VBUS,
107 }
108};
109
110static struct regmap_irq_chip tahvo_irq_chip = {
111 .name = "TAHVO",
112 .irqs = tahvo_irqs,
113 .num_irqs = ARRAY_SIZE(tahvo_irqs),
114 .num_regs = 1,
115 .status_base = RETU_REG_IDR,
116 .mask_base = TAHVO_REG_IMR,
117 .ack_base = RETU_REG_IDR,
118};
119
120static const struct retu_data {
121 char *chip_name;
122 char *companion_name;
123 struct regmap_irq_chip *irq_chip;
124 const struct mfd_cell *children;
125 int nchildren;
126} retu_data[] = {
127 [0] = {
128 .chip_name = "Retu",
129 .companion_name = "Vilma",
130 .irq_chip = &retu_irq_chip,
131 .children = retu_devs,
132 .nchildren = ARRAY_SIZE(retu_devs),
133 },
134 [1] = {
135 .chip_name = "Tahvo",
136 .companion_name = "Betty",
137 .irq_chip = &tahvo_irq_chip,
138 .children = tahvo_devs,
139 .nchildren = ARRAY_SIZE(tahvo_devs),
140 }
141};
142
143int retu_read(struct retu_dev *rdev, u8 reg)
144{
145 int ret;
146 int value;
147
148 mutex_lock(&rdev->mutex);
149 ret = regmap_read(rdev->regmap, reg, &value);
150 mutex_unlock(&rdev->mutex);
151
152 return ret ? ret : value;
153}
154EXPORT_SYMBOL_GPL(retu_read);
155
156int retu_write(struct retu_dev *rdev, u8 reg, u16 data)
157{
158 int ret;
159
160 mutex_lock(&rdev->mutex);
161 ret = regmap_write(rdev->regmap, reg, data);
162 mutex_unlock(&rdev->mutex);
163
164 return ret;
165}
166EXPORT_SYMBOL_GPL(retu_write);
167
168static void retu_power_off(void)
169{
170 struct retu_dev *rdev = retu_pm_power_off;
171 int reg;
172
173 mutex_lock(&retu_pm_power_off->mutex);
174
175 /* Ignore power button state */
176 regmap_read(rdev->regmap, RETU_REG_CC1, &reg);
177 regmap_write(rdev->regmap, RETU_REG_CC1, reg | 2);
178
179 /* Expire watchdog immediately */
180 regmap_write(rdev->regmap, RETU_REG_WATCHDOG, 0);
181
182 /* Wait for poweroff */
183 for (;;)
184 cpu_relax();
185
186 mutex_unlock(&retu_pm_power_off->mutex);
187}
188
189static int retu_regmap_read(void *context, const void *reg, size_t reg_size,
190 void *val, size_t val_size)
191{
192 int ret;
193 struct device *dev = context;
194 struct i2c_client *i2c = to_i2c_client(dev);
195
196 BUG_ON(reg_size != 1 || val_size != 2);
197
198 ret = i2c_smbus_read_word_data(i2c, *(u8 const *)reg);
199 if (ret < 0)
200 return ret;
201
202 *(u16 *)val = ret;
203 return 0;
204}
205
206static int retu_regmap_write(void *context, const void *data, size_t count)
207{
208 u8 reg;
209 u16 val;
210 struct device *dev = context;
211 struct i2c_client *i2c = to_i2c_client(dev);
212
213 BUG_ON(count != sizeof(reg) + sizeof(val));
214 memcpy(&reg, data, sizeof(reg));
215 memcpy(&val, data + sizeof(reg), sizeof(val));
216 return i2c_smbus_write_word_data(i2c, reg, val);
217}
218
219static struct regmap_bus retu_bus = {
220 .read = retu_regmap_read,
221 .write = retu_regmap_write,
222 .val_format_endian_default = REGMAP_ENDIAN_NATIVE,
223};
224
225static const struct regmap_config retu_config = {
226 .reg_bits = 8,
227 .val_bits = 16,
228};
229
230static int retu_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
231{
232 struct retu_data const *rdat;
233 struct retu_dev *rdev;
234 int ret;
235
236 if (i2c->addr > ARRAY_SIZE(retu_data))
237 return -ENODEV;
238 rdat = &retu_data[i2c->addr - 1];
239
240 rdev = devm_kzalloc(&i2c->dev, sizeof(*rdev), GFP_KERNEL);
241 if (rdev == NULL)
242 return -ENOMEM;
243
244 i2c_set_clientdata(i2c, rdev);
245 rdev->dev = &i2c->dev;
246 mutex_init(&rdev->mutex);
247 rdev->regmap = devm_regmap_init(&i2c->dev, &retu_bus, &i2c->dev,
248 &retu_config);
249 if (IS_ERR(rdev->regmap))
250 return PTR_ERR(rdev->regmap);
251
252 ret = retu_read(rdev, RETU_REG_ASICR);
253 if (ret < 0) {
254 dev_err(rdev->dev, "could not read %s revision: %d\n",
255 rdat->chip_name, ret);
256 return ret;
257 }
258
259 dev_info(rdev->dev, "%s%s%s v%d.%d found\n", rdat->chip_name,
260 (ret & RETU_REG_ASICR_VILMA) ? " & " : "",
261 (ret & RETU_REG_ASICR_VILMA) ? rdat->companion_name : "",
262 (ret >> 4) & 0x7, ret & 0xf);
263
264 /* Mask all interrupts. */
265 ret = retu_write(rdev, rdat->irq_chip->mask_base, 0xffff);
266 if (ret < 0)
267 return ret;
268
269 ret = regmap_add_irq_chip(rdev->regmap, i2c->irq, IRQF_ONESHOT, -1,
270 rdat->irq_chip, &rdev->irq_data);
271 if (ret < 0)
272 return ret;
273
274 ret = mfd_add_devices(rdev->dev, -1, rdat->children, rdat->nchildren,
275 NULL, regmap_irq_chip_get_base(rdev->irq_data),
276 NULL);
277 if (ret < 0) {
278 regmap_del_irq_chip(i2c->irq, rdev->irq_data);
279 return ret;
280 }
281
282 if (i2c->addr == 1 && !pm_power_off) {
283 retu_pm_power_off = rdev;
284 pm_power_off = retu_power_off;
285 }
286
287 return 0;
288}
289
290static int retu_remove(struct i2c_client *i2c)
291{
292 struct retu_dev *rdev = i2c_get_clientdata(i2c);
293
294 if (retu_pm_power_off == rdev) {
295 pm_power_off = NULL;
296 retu_pm_power_off = NULL;
297 }
298 mfd_remove_devices(rdev->dev);
299 regmap_del_irq_chip(i2c->irq, rdev->irq_data);
300
301 return 0;
302}
303
304static const struct i2c_device_id retu_id[] = {
305 { "retu", 0 },
306 { "tahvo", 0 },
307 { }
308};
309MODULE_DEVICE_TABLE(i2c, retu_id);
310
311static const struct of_device_id retu_of_match[] = {
312 { .compatible = "nokia,retu" },
313 { .compatible = "nokia,tahvo" },
314 { }
315};
316MODULE_DEVICE_TABLE(of, retu_of_match);
317
318static struct i2c_driver retu_driver = {
319 .driver = {
320 .name = "retu-mfd",
321 .of_match_table = retu_of_match,
322 },
323 .probe = retu_probe,
324 .remove = retu_remove,
325 .id_table = retu_id,
326};
327module_i2c_driver(retu_driver);
328
329MODULE_DESCRIPTION("Retu MFD driver");
330MODULE_AUTHOR("Juha Yrjölä");
331MODULE_AUTHOR("David Weinehall");
332MODULE_AUTHOR("Mikko Ylinen");
333MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
334MODULE_LICENSE("GPL");
335