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-rw-r--r--arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c237
1 files changed, 237 insertions, 0 deletions
diff --git a/arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c b/arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c
new file mode 100644
index 0000000000..117e7b0799
--- /dev/null
+++ b/arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c
@@ -0,0 +1,237 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * R-Car Generation 2 da9063(L)/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,da9063l", .data = &da9063_msg },
+ { .compatible = "dlg,da9210", .data = &da9210_msg },
+ { /* sentinel */ }
+};
+
+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);
+ of_node_put(pos->np);
+ 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,porter") &&
+ !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)) {
+ of_node_put(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;
+ of_node_put(np);
+ goto err_mem;
+ }
+
+ argsa = &quirk->irq_args;
+ memcpy(&quirk->i2c_msg, id->data, sizeof(quirk->i2c_msg));
+
+ quirk->id = id;
+ quirk->np = of_node_get(np);
+ quirk->i2c_msg.addr = addr;
+
+ ret = of_irq_parse_one(np, 0, argsa);
+ if (ret) { /* Skip invalid entry and continue */
+ of_node_put(np);
+ 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 regulator quirk\n");
+
+ bus_register_notifier(&i2c_bus_type, &regulator_quirk_nb);
+ return 0;
+
+err_free:
+ iounmap(irqc);
+err_mem:
+ list_for_each_entry_safe(pos, tmp, &quirk_list, list) {
+ list_del(&pos->list);
+ of_node_put(pos->np);
+ kfree(pos);
+ }
+
+ return ret;
+}
+
+arch_initcall(rcar_gen2_regulator_quirk);