1 /*
2 * R-Car Generation 2 da9063/da9210 regulator quirk
3 *
4 * The r8a7790/lager and r8a7791/koelsch development boards have da9063 and
5 * da9210 regulators. Both regulators have their interrupt request lines tied
6 * to the same interrupt pin (IRQ2) on the SoC.
7 *
8 * After cold boot or da9063-induced restart, both the da9063 and da9210 seem
9 * to assert their interrupt request lines. Hence as soon as one driver
10 * requests this irq, it gets stuck in an interrupt storm, as it only manages
11 * to deassert its own interrupt request line, and the other driver hasn't
12 * installed an interrupt handler yet.
13 *
14 * To handle this, install a quirk that masks the interrupts in both the
15 * da9063 and da9210. This quirk has to run after the i2c master driver has
16 * been initialized, but before the i2c slave drivers are initialized.
17 *
18 * Copyright (C) 2015 Glider bvba
19 *
20 * This program is free software; you can redistribute it and/or modify
21 * it under the terms of the GNU General Public License as published by
22 * the Free Software Foundation; version 2 of the License.
23 *
24 * This program is distributed in the hope that it will be useful,
25 * but WITHOUT ANY WARRANTY; without even the implied warranty of
26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
27 * GNU General Public License for more details.
28 */
29
30 #include <linux/device.h>
31 #include <linux/i2c.h>
32 #include <linux/init.h>
33 #include <linux/io.h>
34 #include <linux/notifier.h>
35 #include <linux/of.h>
36 #include <linux/mfd/da9063/registers.h>
37
38
39 #define IRQC_BASE 0xe61c0000
40 #define IRQC_MONITOR 0x104 /* IRQn Signal Level Monitor Register */
41
42 #define REGULATOR_IRQ_MASK BIT(2) /* IRQ2, active low */
43
44 /* start of DA9210 System Control and Event Registers */
45 #define DA9210_REG_MASK_A 0x54
46
47 static void __iomem *irqc;
48
49 /* first byte sets the memory pointer, following are consecutive reg values */
50 static u8 da9063_irq_clr[] = { DA9063_REG_IRQ_MASK_A, 0xff, 0xff, 0xff, 0xff };
51 static u8 da9210_irq_clr[] = { DA9210_REG_MASK_A, 0xff, 0xff };
52
53 static struct i2c_msg da9xxx_msgs[2] = {
54 {
55 .addr = 0x58,
56 .len = ARRAY_SIZE(da9063_irq_clr),
57 .buf = da9063_irq_clr,
58 }, {
59 .addr = 0x68,
60 .len = ARRAY_SIZE(da9210_irq_clr),
61 .buf = da9210_irq_clr,
62 },
63 };
64
regulator_quirk_notify(struct notifier_block * nb,unsigned long action,void * data)65 static int regulator_quirk_notify(struct notifier_block *nb,
66 unsigned long action, void *data)
67 {
68 struct device *dev = data;
69 struct i2c_client *client;
70 u32 mon;
71
72 mon = ioread32(irqc + IRQC_MONITOR);
73 dev_dbg(dev, "%s: %ld, IRQC_MONITOR = 0x%x\n", __func__, action, mon);
74 if (mon & REGULATOR_IRQ_MASK)
75 goto remove;
76
77 if (action != BUS_NOTIFY_ADD_DEVICE || dev->type == &i2c_adapter_type)
78 return 0;
79
80 client = to_i2c_client(dev);
81 dev_dbg(dev, "Detected %s\n", client->name);
82
83 if ((client->addr == 0x58 && !strcmp(client->name, "da9063")) ||
84 (client->addr == 0x68 && !strcmp(client->name, "da9210"))) {
85 int ret;
86
87 dev_info(&client->dev, "clearing da9063/da9210 interrupts\n");
88 ret = i2c_transfer(client->adapter, da9xxx_msgs, ARRAY_SIZE(da9xxx_msgs));
89 if (ret != ARRAY_SIZE(da9xxx_msgs))
90 dev_err(&client->dev, "i2c error %d\n", ret);
91 }
92
93 mon = ioread32(irqc + IRQC_MONITOR);
94 if (mon & REGULATOR_IRQ_MASK)
95 goto remove;
96
97 return 0;
98
99 remove:
100 dev_info(dev, "IRQ2 is not asserted, removing quirk\n");
101
102 bus_unregister_notifier(&i2c_bus_type, nb);
103 iounmap(irqc);
104 return 0;
105 }
106
107 static struct notifier_block regulator_quirk_nb = {
108 .notifier_call = regulator_quirk_notify
109 };
110
rcar_gen2_regulator_quirk(void)111 static int __init rcar_gen2_regulator_quirk(void)
112 {
113 u32 mon;
114
115 if (!of_machine_is_compatible("renesas,koelsch") &&
116 !of_machine_is_compatible("renesas,lager") &&
117 !of_machine_is_compatible("renesas,gose"))
118 return -ENODEV;
119
120 irqc = ioremap(IRQC_BASE, PAGE_SIZE);
121 if (!irqc)
122 return -ENOMEM;
123
124 mon = ioread32(irqc + IRQC_MONITOR);
125 if (mon & REGULATOR_IRQ_MASK) {
126 pr_debug("%s: IRQ2 is not asserted, not installing quirk\n",
127 __func__);
128 iounmap(irqc);
129 return 0;
130 }
131
132 pr_info("IRQ2 is asserted, installing da9063/da9210 regulator quirk\n");
133
134 bus_register_notifier(&i2c_bus_type, ®ulator_quirk_nb);
135 return 0;
136 }
137
138 arch_initcall(rcar_gen2_regulator_quirk);
139