Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / arch / arm / mach-shmobile / regulator-quirk-rcar-gen2.c
blob44438f344dc80f9c5073502fbe2019270d8df24a
1 /*
2 * R-Car Generation 2 da9063/da9210 regulator quirk
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.
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.
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.
18 * Copyright (C) 2015 Glider bvba
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.
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.
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>
39 #define IRQC_BASE 0xe61c0000
40 #define IRQC_MONITOR 0x104 /* IRQn Signal Level Monitor Register */
42 #define REGULATOR_IRQ_MASK BIT(2) /* IRQ2, active low */
44 /* start of DA9210 System Control and Event Registers */
45 #define DA9210_REG_MASK_A 0x54
47 static void __iomem *irqc;
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 };
53 static struct i2c_msg da9xxx_msgs[2] = {
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,
65 static int regulator_quirk_notify(struct notifier_block *nb,
66 unsigned long action, void *data)
68 struct device *dev = data;
69 struct i2c_client *client;
70 static bool done;
71 u32 mon;
73 if (done)
74 return 0;
76 mon = ioread32(irqc + IRQC_MONITOR);
77 dev_dbg(dev, "%s: %ld, IRQC_MONITOR = 0x%x\n", __func__, action, mon);
78 if (mon & REGULATOR_IRQ_MASK)
79 goto remove;
81 if (action != BUS_NOTIFY_ADD_DEVICE || dev->type == &i2c_adapter_type)
82 return 0;
84 client = to_i2c_client(dev);
85 dev_dbg(dev, "Detected %s\n", client->name);
87 if ((client->addr == 0x58 && !strcmp(client->name, "da9063")) ||
88 (client->addr == 0x68 && !strcmp(client->name, "da9210"))) {
89 int ret;
91 dev_info(&client->dev, "clearing da9063/da9210 interrupts\n");
92 ret = i2c_transfer(client->adapter, da9xxx_msgs, ARRAY_SIZE(da9xxx_msgs));
93 if (ret != ARRAY_SIZE(da9xxx_msgs))
94 dev_err(&client->dev, "i2c error %d\n", ret);
97 mon = ioread32(irqc + IRQC_MONITOR);
98 if (mon & REGULATOR_IRQ_MASK)
99 goto remove;
101 return 0;
103 remove:
104 dev_info(dev, "IRQ2 is not asserted, removing quirk\n");
106 done = true;
107 iounmap(irqc);
108 return 0;
111 static struct notifier_block regulator_quirk_nb = {
112 .notifier_call = regulator_quirk_notify
115 static int __init rcar_gen2_regulator_quirk(void)
117 u32 mon;
119 if (!of_machine_is_compatible("renesas,koelsch") &&
120 !of_machine_is_compatible("renesas,lager") &&
121 !of_machine_is_compatible("renesas,gose"))
122 return -ENODEV;
124 irqc = ioremap(IRQC_BASE, PAGE_SIZE);
125 if (!irqc)
126 return -ENOMEM;
128 mon = ioread32(irqc + IRQC_MONITOR);
129 if (mon & REGULATOR_IRQ_MASK) {
130 pr_debug("%s: IRQ2 is not asserted, not installing quirk\n",
131 __func__);
132 iounmap(irqc);
133 return 0;
136 pr_info("IRQ2 is asserted, installing da9063/da9210 regulator quirk\n");
138 bus_register_notifier(&i2c_bus_type, &regulator_quirk_nb);
139 return 0;
142 arch_initcall(rcar_gen2_regulator_quirk);