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// SPDX-License-Identifier: GPL-2.0
/*
* R-Car Generation 2 da9063/da9210 regulator quirk
*
* Certain Gen2 development boards have an da9063 and one or more da9210
* regulators. All of these regulators have their interrupt request lines
* tied to the same interrupt pin (IRQ2) on the SoC.
*
* After cold boot or da9063-induced restart, both the da9063 and da9210 seem
* to assert their interrupt request lines. Hence as soon as one driver
* requests this irq, it gets stuck in an interrupt storm, as it only manages
* to deassert its own interrupt request line, and the other driver hasn't
* installed an interrupt handler yet.
*
* To handle this, install a quirk that masks the interrupts in both the
* da9063 and da9210. This quirk has to run after the i2c master driver has
* been initialized, but before the i2c slave drivers are initialized.
*
* Copyright (C) 2015 Glider bvba
*/
#include <linux/device.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/list.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/mfd/da9063/registers.h>
#define IRQC_BASE 0xe61c0000
#define IRQC_MONITOR 0x104 /* IRQn Signal Level Monitor Register */
#define REGULATOR_IRQ_MASK BIT(2) /* IRQ2, active low */
/* start of DA9210 System Control and Event Registers */
#define DA9210_REG_MASK_A 0x54
struct regulator_quirk {
struct list_head list;
const struct of_device_id *id;
struct device_node *np;
struct of_phandle_args irq_args;
struct i2c_msg i2c_msg;
bool shared; /* IRQ line is shared */
};
static LIST_HEAD(quirk_list);
static void __iomem *irqc;
/* first byte sets the memory pointer, following are consecutive reg values */
static u8 da9063_irq_clr[] = { DA9063_REG_IRQ_MASK_A, 0xff, 0xff, 0xff, 0xff };
static u8 da9210_irq_clr[] = { DA9210_REG_MASK_A, 0xff, 0xff };
static struct i2c_msg da9063_msg = {
.len = ARRAY_SIZE(da9063_irq_clr),
.buf = da9063_irq_clr,
};
static struct i2c_msg da9210_msg = {
.len = ARRAY_SIZE(da9210_irq_clr),
.buf = da9210_irq_clr,
};
static const struct of_device_id rcar_gen2_quirk_match[] = {
{ .compatible = "dlg,da9063", .data = &da9063_msg },
{ .compatible = "dlg,da9210", .data = &da9210_msg },
{},
};
static int regulator_quirk_notify(struct notifier_block *nb,
unsigned long action, void *data)
{
struct regulator_quirk *pos, *tmp;
struct device *dev = data;
struct i2c_client *client;
static bool done;
int ret;
u32 mon;
if (done)
return 0;
mon = ioread32(irqc + IRQC_MONITOR);
dev_dbg(dev, "%s: %ld, IRQC_MONITOR = 0x%x\n", __func__, action, mon);
if (mon & REGULATOR_IRQ_MASK)
goto remove;
if (action != BUS_NOTIFY_ADD_DEVICE || dev->type == &i2c_adapter_type)
return 0;
client = to_i2c_client(dev);
dev_dbg(dev, "Detected %s\n", client->name);
/*
* Send message to all PMICs that share an IRQ line to deassert it.
*
* WARNING: This works only if all the PMICs are on the same I2C bus.
*/
list_for_each_entry(pos, &quirk_list, list) {
if (!pos->shared)
continue;
if (pos->np->parent != client->dev.parent->of_node)
continue;
dev_info(&client->dev, "clearing %s@0x%02x interrupts\n",
pos->id->compatible, pos->i2c_msg.addr);
ret = i2c_transfer(client->adapter, &pos->i2c_msg, 1);
if (ret != 1)
dev_err(&client->dev, "i2c error %d\n", ret);
}
mon = ioread32(irqc + IRQC_MONITOR);
if (mon & REGULATOR_IRQ_MASK)
goto remove;
return 0;
remove:
dev_info(dev, "IRQ2 is not asserted, removing quirk\n");
list_for_each_entry_safe(pos, tmp, &quirk_list, list) {
list_del(&pos->list);
kfree(pos);
}
done = true;
iounmap(irqc);
return 0;
}
static struct notifier_block regulator_quirk_nb = {
.notifier_call = regulator_quirk_notify
};
static int __init rcar_gen2_regulator_quirk(void)
{
struct regulator_quirk *quirk, *pos, *tmp;
struct of_phandle_args *argsa, *argsb;
const struct of_device_id *id;
struct device_node *np;
u32 mon, addr;
int ret;
if (!of_machine_is_compatible("renesas,koelsch") &&
!of_machine_is_compatible("renesas,lager") &&
!of_machine_is_compatible("renesas,stout") &&
!of_machine_is_compatible("renesas,gose"))
return -ENODEV;
for_each_matching_node_and_match(np, rcar_gen2_quirk_match, &id) {
if (!of_device_is_available(np))
break;
ret = of_property_read_u32(np, "reg", &addr);
if (ret) /* Skip invalid entry and continue */
continue;
quirk = kzalloc(sizeof(*quirk), GFP_KERNEL);
if (!quirk) {
ret = -ENOMEM;
goto err_mem;
}
argsa = &quirk->irq_args;
memcpy(&quirk->i2c_msg, id->data, sizeof(quirk->i2c_msg));
quirk->id = id;
quirk->np = np;
quirk->i2c_msg.addr = addr;
ret = of_irq_parse_one(np, 0, argsa);
if (ret) { /* Skip invalid entry and continue */
kfree(quirk);
continue;
}
list_for_each_entry(pos, &quirk_list, list) {
argsb = &pos->irq_args;
if (argsa->args_count != argsb->args_count)
continue;
ret = memcmp(argsa->args, argsb->args,
argsa->args_count *
sizeof(argsa->args[0]));
if (!ret) {
pos->shared = true;
quirk->shared = true;
}
}
list_add_tail(&quirk->list, &quirk_list);
}
irqc = ioremap(IRQC_BASE, PAGE_SIZE);
if (!irqc) {
ret = -ENOMEM;
goto err_mem;
}
mon = ioread32(irqc + IRQC_MONITOR);
if (mon & REGULATOR_IRQ_MASK) {
pr_debug("%s: IRQ2 is not asserted, not installing quirk\n",
__func__);
ret = 0;
goto err_free;
}
pr_info("IRQ2 is asserted, installing da9063/da9210 regulator quirk\n");
bus_register_notifier(&i2c_bus_type, ®ulator_quirk_nb);
return 0;
err_free:
iounmap(irqc);
err_mem:
list_for_each_entry_safe(pos, tmp, &quirk_list, list) {
list_del(&pos->list);
kfree(pos);
}
return ret;
}
arch_initcall(rcar_gen2_regulator_quirk);
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