regulator-quirk-rcar-gen2.c

  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
 40struct 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
 49static LIST_HEAD(quirk_list);
 50static void __iomem *irqc;
 51
 52/* first byte sets the memory pointer, following are consecutive reg values */
 53static u8 da9063_irq_clr[] = { DA9063_REG_IRQ_MASK_A, 0xff, 0xff, 0xff, 0xff };
 54static u8 da9210_irq_clr[] = { DA9210_REG_MASK_A, 0xff, 0xff };
 55
 56static struct i2c_msg da9063_msg = {
 57	.len = ARRAY_SIZE(da9063_irq_clr),
 58	.buf = da9063_irq_clr,
 59};
 60
 61static struct i2c_msg da9210_msg = {
 62	.len = ARRAY_SIZE(da9210_irq_clr),
 63	.buf = da9210_irq_clr,
 64};
 65
 66static 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
 73static 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
123remove:
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
137static struct notifier_block regulator_quirk_nb = {
138	.notifier_call = regulator_quirk_notify
139};
140
141static 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, &regulator_quirk_nb);
223	return 0;
224
225err_free:
226	iounmap(irqc);
227err_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
237arch_initcall(rcar_gen2_regulator_quirk);