1 /* 2 * R-Car Generation 2 da9063/da9210 regulator quirk 3 * 4 * Certain Gen2 development boards have an da9063 and one or more da9210 5 * regulators. All of these regulators have their interrupt request lines 6 * tied to the same interrupt pin (IRQ2) on the SoC. 7 * 8 * After cold boot or da9063-induced restart, both the da9063 and da9210 seem 9 * to assert their interrupt request lines. Hence as soon as one driver 10 * requests this irq, it gets stuck in an interrupt storm, as it only manages 11 * to deassert its own interrupt request line, and the other driver hasn't 12 * installed an interrupt handler yet. 13 * 14 * To handle this, install a quirk that masks the interrupts in both the 15 * da9063 and da9210. This quirk has to run after the i2c master driver has 16 * been initialized, but before the i2c slave drivers are initialized. 17 * 18 * Copyright (C) 2015 Glider bvba 19 * 20 * This program is free software; you can redistribute it and/or modify 21 * it under the terms of the GNU General Public License as published by 22 * the Free Software Foundation; version 2 of the License. 23 * 24 * This program is distributed in the hope that it will be useful, 25 * but WITHOUT ANY WARRANTY; without even the implied warranty of 26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 27 * GNU General Public License for more details. 28 */ 29 30 #include <linux/device.h> 31 #include <linux/i2c.h> 32 #include <linux/init.h> 33 #include <linux/io.h> 34 #include <linux/notifier.h> 35 #include <linux/of.h> 36 #include <linux/mfd/da9063/registers.h> 37 38 39 #define IRQC_BASE 0xe61c0000 40 #define IRQC_MONITOR 0x104 /* IRQn Signal Level Monitor Register */ 41 42 #define REGULATOR_IRQ_MASK BIT(2) /* IRQ2, active low */ 43 44 /* start of DA9210 System Control and Event Registers */ 45 #define DA9210_REG_MASK_A 0x54 46 47 static void __iomem *irqc; 48 49 /* first byte sets the memory pointer, following are consecutive reg values */ 50 static u8 da9063_irq_clr[] = { DA9063_REG_IRQ_MASK_A, 0xff, 0xff, 0xff, 0xff }; 51 static u8 da9210_irq_clr[] = { DA9210_REG_MASK_A, 0xff, 0xff }; 52 53 static struct i2c_msg da9xxx_msgs[3] = { 54 { 55 .addr = 0x58, 56 .len = ARRAY_SIZE(da9063_irq_clr), 57 .buf = da9063_irq_clr, 58 }, { 59 .addr = 0x68, 60 .len = ARRAY_SIZE(da9210_irq_clr), 61 .buf = da9210_irq_clr, 62 }, { 63 .addr = 0x70, 64 .len = ARRAY_SIZE(da9210_irq_clr), 65 .buf = da9210_irq_clr, 66 }, 67 }; 68 69 static int regulator_quirk_notify(struct notifier_block *nb, 70 unsigned long action, void *data) 71 { 72 struct device *dev = data; 73 struct i2c_client *client; 74 static bool done; 75 u32 mon; 76 77 if (done) 78 return 0; 79 80 mon = ioread32(irqc + IRQC_MONITOR); 81 dev_dbg(dev, "%s: %ld, IRQC_MONITOR = 0x%x\n", __func__, action, mon); 82 if (mon & REGULATOR_IRQ_MASK) 83 goto remove; 84 85 if (action != BUS_NOTIFY_ADD_DEVICE || dev->type == &i2c_adapter_type) 86 return 0; 87 88 client = to_i2c_client(dev); 89 dev_dbg(dev, "Detected %s\n", client->name); 90 91 if ((client->addr == 0x58 && !strcmp(client->name, "da9063")) || 92 (client->addr == 0x68 && !strcmp(client->name, "da9210")) || 93 (client->addr == 0x70 && !strcmp(client->name, "da9210"))) { 94 int ret, len; 95 96 /* There are two DA9210 on Stout, one on the other boards. */ 97 len = of_machine_is_compatible("renesas,stout") ? 3 : 2; 98 99 dev_info(&client->dev, "clearing da9063/da9210 interrupts\n"); 100 ret = i2c_transfer(client->adapter, da9xxx_msgs, len); 101 if (ret != len) 102 dev_err(&client->dev, "i2c error %d\n", ret); 103 } 104 105 mon = ioread32(irqc + IRQC_MONITOR); 106 if (mon & REGULATOR_IRQ_MASK) 107 goto remove; 108 109 return 0; 110 111 remove: 112 dev_info(dev, "IRQ2 is not asserted, removing quirk\n"); 113 114 done = true; 115 iounmap(irqc); 116 return 0; 117 } 118 119 static struct notifier_block regulator_quirk_nb = { 120 .notifier_call = regulator_quirk_notify 121 }; 122 123 static int __init rcar_gen2_regulator_quirk(void) 124 { 125 u32 mon; 126 127 if (!of_machine_is_compatible("renesas,koelsch") && 128 !of_machine_is_compatible("renesas,lager") && 129 !of_machine_is_compatible("renesas,stout") && 130 !of_machine_is_compatible("renesas,gose")) 131 return -ENODEV; 132 133 irqc = ioremap(IRQC_BASE, PAGE_SIZE); 134 if (!irqc) 135 return -ENOMEM; 136 137 mon = ioread32(irqc + IRQC_MONITOR); 138 if (mon & REGULATOR_IRQ_MASK) { 139 pr_debug("%s: IRQ2 is not asserted, not installing quirk\n", 140 __func__); 141 iounmap(irqc); 142 return 0; 143 } 144 145 pr_info("IRQ2 is asserted, installing da9063/da9210 regulator quirk\n"); 146 147 bus_register_notifier(&i2c_bus_type, ®ulator_quirk_nb); 148 return 0; 149 } 150 151 arch_initcall(rcar_gen2_regulator_quirk); 152