diff options
Diffstat (limited to 'arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c')
| -rw-r--r-- | arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c | 147 |
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 000000000000..384e6e934b87 --- /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, ®ulator_quirk_nb); + return 0; +} + +arch_initcall(rcar_gen2_regulator_quirk); |