1/*
2 * Retu/Tahvo MFD driver
3 *
4 * Copyright (C) 2004, 2005 Nokia Corporation
5 *
6 * Based on code written by Juha Yrj��l��, 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 const 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 const 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)
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 void 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
302static const struct i2c_device_id retu_id[] = {
303	{ "retu", 0 },
304	{ "tahvo", 0 },
305	{ }
306};
307MODULE_DEVICE_TABLE(i2c, retu_id);
308
309static const struct of_device_id retu_of_match[] = {
310	{ .compatible = "nokia,retu" },
311	{ .compatible = "nokia,tahvo" },
312	{ }
313};
314MODULE_DEVICE_TABLE(of, retu_of_match);
315
316static struct i2c_driver retu_driver = {
317	.driver		= {
318		.name = "retu-mfd",
319		.of_match_table = retu_of_match,
320	},
321	.probe		= retu_probe,
322	.remove		= retu_remove,
323	.id_table	= retu_id,
324};
325module_i2c_driver(retu_driver);
326
327MODULE_DESCRIPTION("Retu MFD driver");
328MODULE_AUTHOR("Juha Yrj��l��");
329MODULE_AUTHOR("David Weinehall");
330MODULE_AUTHOR("Mikko Ylinen");
331MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
332MODULE_LICENSE("GPL");
333