summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c
blob: 8e50daa99151686c7fad5981a2fbd6075f680cd0 (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
// SPDX-License-Identifier: GPL-2.0
/*
 * R-Car Generation 2 da9063/da9210 regulator quirk
 *
 * Certain Gen2 development boards have an da9063 and one or more da9210
 * regulators. All of these regulators have their interrupt request lines
 * tied to the same interrupt pin (IRQ2) on the SoC.
 *
 * After cold boot or da9063-induced restart, both the da9063 and da9210 seem
 * to assert their interrupt request lines.  Hence as soon as one driver
 * requests this irq, it gets stuck in an interrupt storm, as it only manages
 * to deassert its own interrupt request line, and the other driver hasn't
 * installed an interrupt handler yet.
 *
 * To handle this, install a quirk that masks the interrupts in both the
 * da9063 and da9210.  This quirk has to run after the i2c master driver has
 * been initialized, but before the i2c slave drivers are initialized.
 *
 * Copyright (C) 2015 Glider bvba
 */

#include <linux/device.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/list.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/mfd/da9063/registers.h>

#define IRQC_BASE		0xe61c0000
#define IRQC_MONITOR		0x104	/* IRQn Signal Level Monitor Register */

#define REGULATOR_IRQ_MASK	BIT(2)	/* IRQ2, active low */

/* start of DA9210 System Control and Event Registers */
#define DA9210_REG_MASK_A		0x54

struct regulator_quirk {
	struct list_head		list;
	const struct of_device_id	*id;
	struct of_phandle_args		irq_args;
	struct i2c_msg			i2c_msg;
	bool				shared;	/* IRQ line is shared */
};

static LIST_HEAD(quirk_list);
static void __iomem *irqc;

/* first byte sets the memory pointer, following are consecutive reg values */
static u8 da9063_irq_clr[] = { DA9063_REG_IRQ_MASK_A, 0xff, 0xff, 0xff, 0xff };
static u8 da9210_irq_clr[] = { DA9210_REG_MASK_A, 0xff, 0xff };

static struct i2c_msg da9063_msg = {
	.len = ARRAY_SIZE(da9063_irq_clr),
	.buf = da9063_irq_clr,
};

static struct i2c_msg da9210_msg = {
	.len = ARRAY_SIZE(da9210_irq_clr),
	.buf = da9210_irq_clr,
};

static const struct of_device_id rcar_gen2_quirk_match[] = {
	{ .compatible = "dlg,da9063", .data = &da9063_msg },
	{ .compatible = "dlg,da9210", .data = &da9210_msg },
	{},
};

static int regulator_quirk_notify(struct notifier_block *nb,
				  unsigned long action, void *data)
{
	struct regulator_quirk *pos, *tmp;
	struct device *dev = data;
	struct i2c_client *client;
	static bool done;
	int ret;
	u32 mon;

	if (done)
		return 0;

	mon = ioread32(irqc + IRQC_MONITOR);
	dev_dbg(dev, "%s: %ld, IRQC_MONITOR = 0x%x\n", __func__, action, mon);
	if (mon & REGULATOR_IRQ_MASK)
		goto remove;

	if (action != BUS_NOTIFY_ADD_DEVICE || dev->type == &i2c_adapter_type)
		return 0;

	client = to_i2c_client(dev);
	dev_dbg(dev, "Detected %s\n", client->name);

	/*
	 * Send message to all PMICs that share an IRQ line to deassert it.
	 *
	 * WARNING: This works only if all the PMICs are on the same I2C bus.
	 */
	list_for_each_entry(pos, &quirk_list, list) {
		if (!pos->shared)
			continue;

		dev_info(&client->dev, "clearing %s@0x%02x interrupts\n",
			 pos->id->compatible, pos->i2c_msg.addr);

		ret = i2c_transfer(client->adapter, &pos->i2c_msg, 1);
		if (ret != 1)
			dev_err(&client->dev, "i2c error %d\n", ret);
	}

	mon = ioread32(irqc + IRQC_MONITOR);
	if (mon & REGULATOR_IRQ_MASK)
		goto remove;

	return 0;

remove:
	dev_info(dev, "IRQ2 is not asserted, removing quirk\n");

	list_for_each_entry_safe(pos, tmp, &quirk_list, list) {
		list_del(&pos->list);
		kfree(pos);
	}

	done = true;
	iounmap(irqc);
	return 0;
}

static struct notifier_block regulator_quirk_nb = {
	.notifier_call = regulator_quirk_notify
};

static int __init rcar_gen2_regulator_quirk(void)
{
	struct regulator_quirk *quirk, *pos, *tmp;
	struct of_phandle_args *argsa, *argsb;
	const struct of_device_id *id;
	struct device_node *np;
	u32 mon, addr;
	int ret;

	if (!of_machine_is_compatible("renesas,koelsch") &&
	    !of_machine_is_compatible("renesas,lager") &&
	    !of_machine_is_compatible("renesas,stout") &&
	    !of_machine_is_compatible("renesas,gose"))
		return -ENODEV;

	for_each_matching_node_and_match(np, rcar_gen2_quirk_match, &id) {
		if (!of_device_is_available(np))
			break;

		ret = of_property_read_u32(np, "reg", &addr);
		if (ret)	/* Skip invalid entry and continue */
			continue;

		quirk = kzalloc(sizeof(*quirk), GFP_KERNEL);
		if (!quirk) {
			ret = -ENOMEM;
			goto err_mem;
		}

		argsa = &quirk->irq_args;
		memcpy(&quirk->i2c_msg, id->data, sizeof(quirk->i2c_msg));

		quirk->id = id;
		quirk->i2c_msg.addr = addr;

		ret = of_irq_parse_one(np, 0, argsa);
		if (ret) {	/* Skip invalid entry and continue */
			kfree(quirk);
			continue;
		}

		list_for_each_entry(pos, &quirk_list, list) {
			argsb = &pos->irq_args;

			if (argsa->args_count != argsb->args_count)
				continue;

			ret = memcmp(argsa->args, argsb->args,
				     argsa->args_count *
				     sizeof(argsa->args[0]));
			if (!ret) {
				pos->shared = true;
				quirk->shared = true;
			}
		}

		list_add_tail(&quirk->list, &quirk_list);
	}

	irqc = ioremap(IRQC_BASE, PAGE_SIZE);
	if (!irqc) {
		ret = -ENOMEM;
		goto err_mem;
	}

	mon = ioread32(irqc + IRQC_MONITOR);
	if (mon & REGULATOR_IRQ_MASK) {
		pr_debug("%s: IRQ2 is not asserted, not installing quirk\n",
			 __func__);
		ret = 0;
		goto err_free;
	}

	pr_info("IRQ2 is asserted, installing da9063/da9210 regulator quirk\n");

	bus_register_notifier(&i2c_bus_type, &regulator_quirk_nb);
	return 0;

err_free:
	iounmap(irqc);
err_mem:
	list_for_each_entry_safe(pos, tmp, &quirk_list, list) {
		list_del(&pos->list);
		kfree(pos);
	}

	return ret;
}

arch_initcall(rcar_gen2_regulator_quirk);