arm64: dts: Revert "specify console via command line"
[linux/fpc-iii.git] / arch / arm / mach-shmobile / regulator-quirk-rcar-gen2.c
blobee949255ced3f01ad4256b2b7bea3ba669006309
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * R-Car Generation 2 da9063(L)/da9210 regulator quirk
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.
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.
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.
19 * Copyright (C) 2015 Glider bvba
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>
32 #define IRQC_BASE 0xe61c0000
33 #define IRQC_MONITOR 0x104 /* IRQn Signal Level Monitor Register */
35 #define REGULATOR_IRQ_MASK BIT(2) /* IRQ2, active low */
37 /* start of DA9210 System Control and Event Registers */
38 #define DA9210_REG_MASK_A 0x54
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 */
49 static LIST_HEAD(quirk_list);
50 static void __iomem *irqc;
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 };
56 static struct i2c_msg da9063_msg = {
57 .len = ARRAY_SIZE(da9063_irq_clr),
58 .buf = da9063_irq_clr,
61 static struct i2c_msg da9210_msg = {
62 .len = ARRAY_SIZE(da9210_irq_clr),
63 .buf = da9210_irq_clr,
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 {},
73 static int regulator_quirk_notify(struct notifier_block *nb,
74 unsigned long action, void *data)
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;
83 if (done)
84 return 0;
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;
91 if (action != BUS_NOTIFY_ADD_DEVICE || dev->type == &i2c_adapter_type)
92 return 0;
94 client = to_i2c_client(dev);
95 dev_dbg(dev, "Detected %s\n", client->name);
98 * Send message to all PMICs that share an IRQ line to deassert it.
100 * WARNING: This works only if all the PMICs are on the same I2C bus.
102 list_for_each_entry(pos, &quirk_list, list) {
103 if (!pos->shared)
104 continue;
106 if (pos->np->parent != client->dev.parent->of_node)
107 continue;
109 dev_info(&client->dev, "clearing %s@0x%02x interrupts\n",
110 pos->id->compatible, pos->i2c_msg.addr);
112 ret = i2c_transfer(client->adapter, &pos->i2c_msg, 1);
113 if (ret != 1)
114 dev_err(&client->dev, "i2c error %d\n", ret);
117 mon = ioread32(irqc + IRQC_MONITOR);
118 if (mon & REGULATOR_IRQ_MASK)
119 goto remove;
121 return 0;
123 remove:
124 dev_info(dev, "IRQ2 is not asserted, removing quirk\n");
126 list_for_each_entry_safe(pos, tmp, &quirk_list, list) {
127 list_del(&pos->list);
128 kfree(pos);
131 done = true;
132 iounmap(irqc);
133 return 0;
136 static struct notifier_block regulator_quirk_nb = {
137 .notifier_call = regulator_quirk_notify
140 static int __init rcar_gen2_regulator_quirk(void)
142 struct regulator_quirk *quirk, *pos, *tmp;
143 struct of_phandle_args *argsa, *argsb;
144 const struct of_device_id *id;
145 struct device_node *np;
146 u32 mon, addr;
147 int ret;
149 if (!of_machine_is_compatible("renesas,koelsch") &&
150 !of_machine_is_compatible("renesas,lager") &&
151 !of_machine_is_compatible("renesas,porter") &&
152 !of_machine_is_compatible("renesas,stout") &&
153 !of_machine_is_compatible("renesas,gose"))
154 return -ENODEV;
156 for_each_matching_node_and_match(np, rcar_gen2_quirk_match, &id) {
157 if (!of_device_is_available(np))
158 break;
160 ret = of_property_read_u32(np, "reg", &addr);
161 if (ret) /* Skip invalid entry and continue */
162 continue;
164 quirk = kzalloc(sizeof(*quirk), GFP_KERNEL);
165 if (!quirk) {
166 ret = -ENOMEM;
167 goto err_mem;
170 argsa = &quirk->irq_args;
171 memcpy(&quirk->i2c_msg, id->data, sizeof(quirk->i2c_msg));
173 quirk->id = id;
174 quirk->np = np;
175 quirk->i2c_msg.addr = addr;
177 ret = of_irq_parse_one(np, 0, argsa);
178 if (ret) { /* Skip invalid entry and continue */
179 kfree(quirk);
180 continue;
183 list_for_each_entry(pos, &quirk_list, list) {
184 argsb = &pos->irq_args;
186 if (argsa->args_count != argsb->args_count)
187 continue;
189 ret = memcmp(argsa->args, argsb->args,
190 argsa->args_count *
191 sizeof(argsa->args[0]));
192 if (!ret) {
193 pos->shared = true;
194 quirk->shared = true;
198 list_add_tail(&quirk->list, &quirk_list);
201 irqc = ioremap(IRQC_BASE, PAGE_SIZE);
202 if (!irqc) {
203 ret = -ENOMEM;
204 goto err_mem;
207 mon = ioread32(irqc + IRQC_MONITOR);
208 if (mon & REGULATOR_IRQ_MASK) {
209 pr_debug("%s: IRQ2 is not asserted, not installing quirk\n",
210 __func__);
211 ret = 0;
212 goto err_free;
215 pr_info("IRQ2 is asserted, installing regulator quirk\n");
217 bus_register_notifier(&i2c_bus_type, &regulator_quirk_nb);
218 return 0;
220 err_free:
221 iounmap(irqc);
222 err_mem:
223 list_for_each_entry_safe(pos, tmp, &quirk_list, list) {
224 list_del(&pos->list);
225 kfree(pos);
228 return ret;
231 arch_initcall(rcar_gen2_regulator_quirk);