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 | 237 |
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, ®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); + of_node_put(pos->np); + kfree(pos); + } + + return ret; +} + +arch_initcall(rcar_gen2_regulator_quirk); |