1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * R-Car Generation 2 da9063(L)/da9210 regulator quirk
4 *
5 * Certain Gen2 development boards have an da9063 and one or more da9210
6 * regulators. All of these regulators have their interrupt request lines
7 * tied to the same interrupt pin (IRQ2) on the SoC.
8 *
9 * After cold boot or da9063-induced restart, both the da9063 and da9210 seem
10 * to assert their interrupt request lines. Hence as soon as one driver
11 * requests this irq, it gets stuck in an interrupt storm, as it only manages
12 * to deassert its own interrupt request line, and the other driver hasn't
13 * installed an interrupt handler yet.
14 *
15 * To handle this, install a quirk that masks the interrupts in both the
16 * da9063 and da9210. This quirk has to run after the i2c master driver has
17 * been initialized, but before the i2c slave drivers are initialized.
18 *
19 * Copyright (C) 2015 Glider bvba
20 */
21
22 #include <linux/device.h>
23 #include <linux/i2c.h>
24 #include <linux/init.h>
25 #include <linux/io.h>
26 #include <linux/list.h>
27 #include <linux/notifier.h>
28 #include <linux/of.h>
29 #include <linux/of_irq.h>
30 #include <linux/mfd/da9063/registers.h>
31
32 #define IRQC_BASE 0xe61c0000
33 #define IRQC_MONITOR 0x104 /* IRQn Signal Level Monitor Register */
34
35 #define REGULATOR_IRQ_MASK BIT(2) /* IRQ2, active low */
36
37 /* start of DA9210 System Control and Event Registers */
38 #define DA9210_REG_MASK_A 0x54
39
40 struct regulator_quirk {
41 struct list_head list;
42 const struct of_device_id *id;
43 struct device_node *np;
44 struct of_phandle_args irq_args;
45 struct i2c_msg i2c_msg;
46 bool shared; /* IRQ line is shared */
47 };
48
49 static LIST_HEAD(quirk_list);
50 static void __iomem *irqc;
51
52 /* first byte sets the memory pointer, following are consecutive reg values */
53 static u8 da9063_irq_clr[] = { DA9063_REG_IRQ_MASK_A, 0xff, 0xff, 0xff, 0xff };
54 static u8 da9210_irq_clr[] = { DA9210_REG_MASK_A, 0xff, 0xff };
55
56 static struct i2c_msg da9063_msg = {
57 .len = ARRAY_SIZE(da9063_irq_clr),
58 .buf = da9063_irq_clr,
59 };
60
61 static struct i2c_msg da9210_msg = {
62 .len = ARRAY_SIZE(da9210_irq_clr),
63 .buf = da9210_irq_clr,
64 };
65
66 static const struct of_device_id rcar_gen2_quirk_match[] = {
67 { .compatible = "dlg,da9063", .data = &da9063_msg },
68 { .compatible = "dlg,da9063l", .data = &da9063_msg },
69 { .compatible = "dlg,da9210", .data = &da9210_msg },
70 { /* sentinel */ }
71 };
72
regulator_quirk_notify(struct notifier_block * nb,unsigned long action,void * data)73 static int regulator_quirk_notify(struct notifier_block *nb,
74 unsigned long action, void *data)
75 {
76 struct regulator_quirk *pos, *tmp;
77 struct device *dev = data;
78 struct i2c_client *client;
79 static bool done;
80 int ret;
81 u32 mon;
82
83 if (done)
84 return 0;
85
86 mon = ioread32(irqc + IRQC_MONITOR);
87 dev_dbg(dev, "%s: %ld, IRQC_MONITOR = 0x%x\n", __func__, action, mon);
88 if (mon & REGULATOR_IRQ_MASK)
89 goto remove;
90
91 if (action != BUS_NOTIFY_ADD_DEVICE || dev->type == &i2c_adapter_type)
92 return 0;
93
94 client = to_i2c_client(dev);
95 dev_dbg(dev, "Detected %s\n", client->name);
96
97 /*
98 * Send message to all PMICs that share an IRQ line to deassert it.
99 *
100 * WARNING: This works only if all the PMICs are on the same I2C bus.
101 */
102 list_for_each_entry(pos, &quirk_list, list) {
103 if (!pos->shared)
104 continue;
105
106 if (pos->np->parent != client->dev.parent->of_node)
107 continue;
108
109 dev_info(&client->dev, "clearing %s@0x%02x interrupts\n",
110 pos->id->compatible, pos->i2c_msg.addr);
111
112 ret = i2c_transfer(client->adapter, &pos->i2c_msg, 1);
113 if (ret != 1)
114 dev_err(&client->dev, "i2c error %d\n", ret);
115 }
116
117 mon = ioread32(irqc + IRQC_MONITOR);
118 if (mon & REGULATOR_IRQ_MASK)
119 goto remove;
120
121 return 0;
122
123 remove:
124 dev_info(dev, "IRQ2 is not asserted, removing quirk\n");
125
126 list_for_each_entry_safe(pos, tmp, &quirk_list, list) {
127 list_del(&pos->list);
128 of_node_put(pos->np);
129 kfree(pos);
130 }
131
132 done = true;
133 iounmap(irqc);
134 return 0;
135 }
136
137 static struct notifier_block regulator_quirk_nb = {
138 .notifier_call = regulator_quirk_notify
139 };
140
rcar_gen2_regulator_quirk(void)141 static int __init rcar_gen2_regulator_quirk(void)
142 {
143 struct regulator_quirk *quirk, *pos, *tmp;
144 struct of_phandle_args *argsa, *argsb;
145 const struct of_device_id *id;
146 struct device_node *np;
147 u32 mon, addr;
148 int ret;
149
150 if (!of_machine_is_compatible("renesas,koelsch") &&
151 !of_machine_is_compatible("renesas,lager") &&
152 !of_machine_is_compatible("renesas,porter") &&
153 !of_machine_is_compatible("renesas,stout") &&
154 !of_machine_is_compatible("renesas,gose"))
155 return -ENODEV;
156
157 for_each_matching_node_and_match(np, rcar_gen2_quirk_match, &id) {
158 if (!of_device_is_available(np)) {
159 of_node_put(np);
160 break;
161 }
162
163 ret = of_property_read_u32(np, "reg", &addr);
164 if (ret) /* Skip invalid entry and continue */
165 continue;
166
167 quirk = kzalloc(sizeof(*quirk), GFP_KERNEL);
168 if (!quirk) {
169 ret = -ENOMEM;
170 of_node_put(np);
171 goto err_mem;
172 }
173
174 argsa = &quirk->irq_args;
175 memcpy(&quirk->i2c_msg, id->data, sizeof(quirk->i2c_msg));
176
177 quirk->id = id;
178 quirk->np = of_node_get(np);
179 quirk->i2c_msg.addr = addr;
180
181 ret = of_irq_parse_one(np, 0, argsa);
182 if (ret) { /* Skip invalid entry and continue */
183 of_node_put(np);
184 kfree(quirk);
185 continue;
186 }
187
188 list_for_each_entry(pos, &quirk_list, list) {
189 argsb = &pos->irq_args;
190
191 if (argsa->args_count != argsb->args_count)
192 continue;
193
194 ret = memcmp(argsa->args, argsb->args,
195 argsa->args_count *
196 sizeof(argsa->args[0]));
197 if (!ret) {
198 pos->shared = true;
199 quirk->shared = true;
200 }
201 }
202
203 list_add_tail(&quirk->list, &quirk_list);
204 }
205
206 irqc = ioremap(IRQC_BASE, PAGE_SIZE);
207 if (!irqc) {
208 ret = -ENOMEM;
209 goto err_mem;
210 }
211
212 mon = ioread32(irqc + IRQC_MONITOR);
213 if (mon & REGULATOR_IRQ_MASK) {
214 pr_debug("%s: IRQ2 is not asserted, not installing quirk\n",
215 __func__);
216 ret = 0;
217 goto err_free;
218 }
219
220 pr_info("IRQ2 is asserted, installing regulator quirk\n");
221
222 bus_register_notifier(&i2c_bus_type, ®ulator_quirk_nb);
223 return 0;
224
225 err_free:
226 iounmap(irqc);
227 err_mem:
228 list_for_each_entry_safe(pos, tmp, &quirk_list, list) {
229 list_del(&pos->list);
230 of_node_put(pos->np);
231 kfree(pos);
232 }
233
234 return ret;
235 }
236
237 arch_initcall(rcar_gen2_regulator_quirk);
238