summaryrefslogtreecommitdiff
path: root/arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c')
-rw-r--r--arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c147
1 files changed, 147 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 000000000..384e6e934
--- /dev/null
+++ b/arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c
@@ -0,0 +1,147 @@
+/*
+ * R-Car Generation 2 da9063/da9210 regulator quirk
+ *
+ * The r8a7790/lager and r8a7791/koelsch development boards have da9063 and
+ * da9210 regulators. Both 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
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/notifier.h>
+#include <linux/of.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 */
+
+static void __iomem *irqc;
+
+static const u8 da9063_mask_regs[] = {
+ DA9063_REG_IRQ_MASK_A,
+ DA9063_REG_IRQ_MASK_B,
+ DA9063_REG_IRQ_MASK_C,
+ DA9063_REG_IRQ_MASK_D,
+};
+
+/* DA9210 System Control and Event Registers */
+#define DA9210_REG_MASK_A 0x54
+#define DA9210_REG_MASK_B 0x55
+
+static const u8 da9210_mask_regs[] = {
+ DA9210_REG_MASK_A,
+ DA9210_REG_MASK_B,
+};
+
+static void da9xxx_mask_irqs(struct i2c_client *client, const u8 regs[],
+ unsigned int nregs)
+{
+ unsigned int i;
+
+ dev_info(&client->dev, "Masking %s interrupt sources\n", client->name);
+
+ for (i = 0; i < nregs; i++) {
+ int error = i2c_smbus_write_byte_data(client, regs[i], ~0);
+ if (error) {
+ dev_err(&client->dev, "i2c error %d\n", error);
+ return;
+ }
+ }
+}
+
+static int regulator_quirk_notify(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct device *dev = data;
+ struct i2c_client *client;
+ u32 mon;
+
+ 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);
+
+ if ((client->addr == 0x58 && !strcmp(client->name, "da9063")))
+ da9xxx_mask_irqs(client, da9063_mask_regs,
+ ARRAY_SIZE(da9063_mask_regs));
+ else if (client->addr == 0x68 && !strcmp(client->name, "da9210"))
+ da9xxx_mask_irqs(client, da9210_mask_regs,
+ ARRAY_SIZE(da9210_mask_regs));
+
+ 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");
+
+ bus_unregister_notifier(&i2c_bus_type, nb);
+ iounmap(irqc);
+ return 0;
+}
+
+static struct notifier_block regulator_quirk_nb = {
+ .notifier_call = regulator_quirk_notify
+};
+
+static int __init rcar_gen2_regulator_quirk(void)
+{
+ u32 mon;
+
+ if (!of_machine_is_compatible("renesas,koelsch") &&
+ !of_machine_is_compatible("renesas,lager"))
+ return -ENODEV;
+
+ irqc = ioremap(IRQC_BASE, PAGE_SIZE);
+ if (!irqc)
+ return -ENOMEM;
+
+ mon = ioread32(irqc + IRQC_MONITOR);
+ if (mon & REGULATOR_IRQ_MASK) {
+ pr_debug("%s: IRQ2 is not asserted, not installing quirk\n",
+ __func__);
+ iounmap(irqc);
+ return 0;
+ }
+
+ pr_info("IRQ2 is asserted, installing da9063/da9210 regulator quirk\n");
+
+ bus_register_notifier(&i2c_bus_type, &regulator_quirk_nb);
+ return 0;
+}
+
+arch_initcall(rcar_gen2_regulator_quirk);