aboutsummaryrefslogtreecommitdiff
path: root/drivers/mfd/retu-mfd.c
blob: 3ba048655bf37fe5a9b1f1ff2ad7a2e6748fe0c7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
/*
 * Retu MFD driver
 *
 * Copyright (C) 2004, 2005 Nokia Corporation
 *
 * Based on code written by Juha Yrjölä, David Weinehall and Mikko Ylinen.
 * Rewritten by Aaro Koskinen.
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License. See the file "COPYING" in the main directory of this
 * archive for more details.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */

#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/irq.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/mfd/core.h>
#include <linux/mfd/retu.h>
#include <linux/interrupt.h>
#include <linux/moduleparam.h>

/* Registers */
#define RETU_REG_ASICR		0x00		/* ASIC ID and revision */
#define RETU_REG_ASICR_VILMA	(1 << 7)	/* Bit indicating Vilma */
#define RETU_REG_IDR		0x01		/* Interrupt ID */
#define RETU_REG_IMR		0x02		/* Interrupt mask */

/* Interrupt sources */
#define RETU_INT_PWR		0		/* Power button */

struct retu_dev {
	struct regmap			*regmap;
	struct device			*dev;
	struct mutex			mutex;
	struct regmap_irq_chip_data	*irq_data;
};

static struct resource retu_pwrbutton_res[] = {
	{
		.name	= "retu-pwrbutton",
		.start	= RETU_INT_PWR,
		.end	= RETU_INT_PWR,
		.flags	= IORESOURCE_IRQ,
	},
};

static struct mfd_cell retu_devs[] = {
	{
		.name		= "retu-wdt"
	},
	{
		.name		= "retu-pwrbutton",
		.resources	= retu_pwrbutton_res,
		.num_resources	= ARRAY_SIZE(retu_pwrbutton_res),
	}
};

static struct regmap_irq retu_irqs[] = {
	[RETU_INT_PWR] = {
		.mask = 1 << RETU_INT_PWR,
	}
};

static struct regmap_irq_chip retu_irq_chip = {
	.name		= "RETU",
	.irqs		= retu_irqs,
	.num_irqs	= ARRAY_SIZE(retu_irqs),
	.num_regs	= 1,
	.status_base	= RETU_REG_IDR,
	.mask_base	= RETU_REG_IMR,
	.ack_base	= RETU_REG_IDR,
};

/* Retu device registered for the power off. */
static struct retu_dev *retu_pm_power_off;

int retu_read(struct retu_dev *rdev, u8 reg)
{
	int ret;
	int value;

	mutex_lock(&rdev->mutex);
	ret = regmap_read(rdev->regmap, reg, &value);
	mutex_unlock(&rdev->mutex);

	return ret ? ret : value;
}
EXPORT_SYMBOL_GPL(retu_read);

int retu_write(struct retu_dev *rdev, u8 reg, u16 data)
{
	int ret;

	mutex_lock(&rdev->mutex);
	ret = regmap_write(rdev->regmap, reg, data);
	mutex_unlock(&rdev->mutex);

	return ret;
}
EXPORT_SYMBOL_GPL(retu_write);

static void retu_power_off(void)
{
	struct retu_dev *rdev = retu_pm_power_off;
	int reg;

	mutex_lock(&retu_pm_power_off->mutex);

	/* Ignore power button state */
	regmap_read(rdev->regmap, RETU_REG_CC1, &reg);
	regmap_write(rdev->regmap, RETU_REG_CC1, reg | 2);

	/* Expire watchdog immediately */
	regmap_write(rdev->regmap, RETU_REG_WATCHDOG, 0);

	/* Wait for poweroff */
	for (;;)
		cpu_relax();

	mutex_unlock(&retu_pm_power_off->mutex);
}

static int retu_regmap_read(void *context, const void *reg, size_t reg_size,
			    void *val, size_t val_size)
{
	int ret;
	struct device *dev = context;
	struct i2c_client *i2c = to_i2c_client(dev);

	BUG_ON(reg_size != 1 || val_size != 2);

	ret = i2c_smbus_read_word_data(i2c, *(u8 const *)reg);
	if (ret < 0)
		return ret;

	*(u16 *)val = ret;
	return 0;
}

static int retu_regmap_write(void *context, const void *data, size_t count)
{
	u8 reg;
	u16 val;
	struct device *dev = context;
	struct i2c_client *i2c = to_i2c_client(dev);

	BUG_ON(count != sizeof(reg) + sizeof(val));
	memcpy(&reg, data, sizeof(reg));
	memcpy(&val, data + sizeof(reg), sizeof(val));
	return i2c_smbus_write_word_data(i2c, reg, val);
}

static struct regmap_bus retu_bus = {
	.read = retu_regmap_read,
	.write = retu_regmap_write,
	.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
};

static struct regmap_config retu_config = {
	.reg_bits = 8,
	.val_bits = 16,
};

static int retu_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
{
	struct retu_dev *rdev;
	int ret;

	rdev = devm_kzalloc(&i2c->dev, sizeof(*rdev), GFP_KERNEL);
	if (rdev == NULL)
		return -ENOMEM;

	i2c_set_clientdata(i2c, rdev);
	rdev->dev = &i2c->dev;
	mutex_init(&rdev->mutex);
	rdev->regmap = devm_regmap_init(&i2c->dev, &retu_bus, &i2c->dev,
					&retu_config);
	if (IS_ERR(rdev->regmap))
		return PTR_ERR(rdev->regmap);

	ret = retu_read(rdev, RETU_REG_ASICR);
	if (ret < 0) {
		dev_err(rdev->dev, "could not read Retu revision: %d\n", ret);
		return ret;
	}

	dev_info(rdev->dev, "Retu%s v%d.%d found\n",
		 (ret & RETU_REG_ASICR_VILMA) ? " & Vilma" : "",
		 (ret >> 4) & 0x7, ret & 0xf);

	/* Mask all RETU interrupts. */
	ret = retu_write(rdev, RETU_REG_IMR, 0xffff);
	if (ret < 0)
		return ret;

	ret = regmap_add_irq_chip(rdev->regmap, i2c->irq, IRQF_ONESHOT, -1,
				  &retu_irq_chip, &rdev->irq_data);
	if (ret < 0)
		return ret;

	ret = mfd_add_devices(rdev->dev, -1, retu_devs, ARRAY_SIZE(retu_devs),
			      NULL, regmap_irq_chip_get_base(rdev->irq_data),
			      NULL);
	if (ret < 0) {
		regmap_del_irq_chip(i2c->irq, rdev->irq_data);
		return ret;
	}

	if (!pm_power_off) {
		retu_pm_power_off = rdev;
		pm_power_off	  = retu_power_off;
	}

	return 0;
}

static int retu_remove(struct i2c_client *i2c)
{
	struct retu_dev *rdev = i2c_get_clientdata(i2c);

	if (retu_pm_power_off == rdev) {
		pm_power_off	  = NULL;
		retu_pm_power_off = NULL;
	}
	mfd_remove_devices(rdev->dev);
	regmap_del_irq_chip(i2c->irq, rdev->irq_data);

	return 0;
}

static const struct i2c_device_id retu_id[] = {
	{ "retu-mfd", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, retu_id);

static struct i2c_driver retu_driver = {
	.driver		= {
		.name = "retu-mfd",
		.owner = THIS_MODULE,
	},
	.probe		= retu_probe,
	.remove		= retu_remove,
	.id_table	= retu_id,
};
module_i2c_driver(retu_driver);

MODULE_DESCRIPTION("Retu MFD driver");
MODULE_AUTHOR("Juha Yrjölä");
MODULE_AUTHOR("David Weinehall");
MODULE_AUTHOR("Mikko Ylinen");
MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
MODULE_LICENSE("GPL");