1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * R-Car Generation 2 da9063/da9210 regulator quirk 4 * 5 * Certain Gen2 development boards have an da9063 and one or more da9210 6 * regulators. All of these regulators have their interrupt request lines 7 * tied to the same interrupt pin (IRQ2) on the SoC. 8 * 9 * After cold boot or da9063-induced restart, both the da9063 and da9210 seem 10 * to assert their interrupt request lines. Hence as soon as one driver 11 * requests this irq, it gets stuck in an interrupt storm, as it only manages 12 * to deassert its own interrupt request line, and the other driver hasn't 13 * installed an interrupt handler yet. 14 * 15 * To handle this, install a quirk that masks the interrupts in both the 16 * da9063 and da9210. This quirk has to run after the i2c master driver has 17 * been initialized, but before the i2c slave drivers are initialized. 18 * 19 * Copyright (C) 2015 Glider bvba 20 */ 21 22 #include <linux/device.h> 23 #include <linux/i2c.h> 24 #include <linux/init.h> 25 #include <linux/io.h> 26 #include <linux/list.h> 27 #include <linux/notifier.h> 28 #include <linux/of.h> 29 #include <linux/of_irq.h> 30 #include <linux/mfd/da9063/registers.h> 31 32 #define IRQC_BASE 0xe61c0000 33 #define IRQC_MONITOR 0x104 /* IRQn Signal Level Monitor Register */ 34 35 #define REGULATOR_IRQ_MASK BIT(2) /* IRQ2, active low */ 36 37 /* start of DA9210 System Control and Event Registers */ 38 #define DA9210_REG_MASK_A 0x54 39 40 struct regulator_quirk { 41 struct list_head list; 42 const struct of_device_id *id; 43 struct of_phandle_args irq_args; 44 struct i2c_msg i2c_msg; 45 bool shared; /* IRQ line is shared */ 46 }; 47 48 static LIST_HEAD(quirk_list); 49 static void __iomem *irqc; 50 51 /* first byte sets the memory pointer, following are consecutive reg values */ 52 static u8 da9063_irq_clr[] = { DA9063_REG_IRQ_MASK_A, 0xff, 0xff, 0xff, 0xff }; 53 static u8 da9210_irq_clr[] = { DA9210_REG_MASK_A, 0xff, 0xff }; 54 55 static struct i2c_msg da9063_msg = { 56 .len = ARRAY_SIZE(da9063_irq_clr), 57 .buf = da9063_irq_clr, 58 }; 59 60 static struct i2c_msg da9210_msg = { 61 .len = ARRAY_SIZE(da9210_irq_clr), 62 .buf = da9210_irq_clr, 63 }; 64 65 static const struct of_device_id rcar_gen2_quirk_match[] = { 66 { .compatible = "dlg,da9063", .data = &da9063_msg }, 67 { .compatible = "dlg,da9210", .data = &da9210_msg }, 68 {}, 69 }; 70 71 static int regulator_quirk_notify(struct notifier_block *nb, 72 unsigned long action, void *data) 73 { 74 struct regulator_quirk *pos, *tmp; 75 struct device *dev = data; 76 struct i2c_client *client; 77 static bool done; 78 int ret; 79 u32 mon; 80 81 if (done) 82 return 0; 83 84 mon = ioread32(irqc + IRQC_MONITOR); 85 dev_dbg(dev, "%s: %ld, IRQC_MONITOR = 0x%x\n", __func__, action, mon); 86 if (mon & REGULATOR_IRQ_MASK) 87 goto remove; 88 89 if (action != BUS_NOTIFY_ADD_DEVICE || dev->type == &i2c_adapter_type) 90 return 0; 91 92 client = to_i2c_client(dev); 93 dev_dbg(dev, "Detected %s\n", client->name); 94 95 /* 96 * Send message to all PMICs that share an IRQ line to deassert it. 97 * 98 * WARNING: This works only if all the PMICs are on the same I2C bus. 99 */ 100 list_for_each_entry(pos, &quirk_list, list) { 101 if (!pos->shared) 102 continue; 103 104 dev_info(&client->dev, "clearing %s@0x%02x interrupts\n", 105 pos->id->compatible, pos->i2c_msg.addr); 106 107 ret = i2c_transfer(client->adapter, &pos->i2c_msg, 1); 108 if (ret != 1) 109 dev_err(&client->dev, "i2c error %d\n", ret); 110 } 111 112 mon = ioread32(irqc + IRQC_MONITOR); 113 if (mon & REGULATOR_IRQ_MASK) 114 goto remove; 115 116 return 0; 117 118 remove: 119 dev_info(dev, "IRQ2 is not asserted, removing quirk\n"); 120 121 list_for_each_entry_safe(pos, tmp, &quirk_list, list) { 122 list_del(&pos->list); 123 kfree(pos); 124 } 125 126 done = true; 127 iounmap(irqc); 128 return 0; 129 } 130 131 static struct notifier_block regulator_quirk_nb = { 132 .notifier_call = regulator_quirk_notify 133 }; 134 135 static int __init rcar_gen2_regulator_quirk(void) 136 { 137 struct regulator_quirk *quirk, *pos, *tmp; 138 struct of_phandle_args *argsa, *argsb; 139 const struct of_device_id *id; 140 struct device_node *np; 141 u32 mon, addr; 142 int ret; 143 144 if (!of_machine_is_compatible("renesas,koelsch") && 145 !of_machine_is_compatible("renesas,lager") && 146 !of_machine_is_compatible("renesas,stout") && 147 !of_machine_is_compatible("renesas,gose")) 148 return -ENODEV; 149 150 for_each_matching_node_and_match(np, rcar_gen2_quirk_match, &id) { 151 if (!of_device_is_available(np)) 152 break; 153 154 ret = of_property_read_u32(np, "reg", &addr); 155 if (ret) /* Skip invalid entry and continue */ 156 continue; 157 158 quirk = kzalloc(sizeof(*quirk), GFP_KERNEL); 159 if (!quirk) { 160 ret = -ENOMEM; 161 goto err_mem; 162 } 163 164 argsa = &quirk->irq_args; 165 memcpy(&quirk->i2c_msg, id->data, sizeof(quirk->i2c_msg)); 166 167 quirk->id = id; 168 quirk->i2c_msg.addr = addr; 169 170 ret = of_irq_parse_one(np, 0, argsa); 171 if (ret) { /* Skip invalid entry and continue */ 172 kfree(quirk); 173 continue; 174 } 175 176 list_for_each_entry(pos, &quirk_list, list) { 177 argsb = &pos->irq_args; 178 179 if (argsa->args_count != argsb->args_count) 180 continue; 181 182 ret = memcmp(argsa->args, argsb->args, 183 argsa->args_count * 184 sizeof(argsa->args[0])); 185 if (!ret) { 186 pos->shared = true; 187 quirk->shared = true; 188 } 189 } 190 191 list_add_tail(&quirk->list, &quirk_list); 192 } 193 194 irqc = ioremap(IRQC_BASE, PAGE_SIZE); 195 if (!irqc) { 196 ret = -ENOMEM; 197 goto err_mem; 198 } 199 200 mon = ioread32(irqc + IRQC_MONITOR); 201 if (mon & REGULATOR_IRQ_MASK) { 202 pr_debug("%s: IRQ2 is not asserted, not installing quirk\n", 203 __func__); 204 ret = 0; 205 goto err_free; 206 } 207 208 pr_info("IRQ2 is asserted, installing da9063/da9210 regulator quirk\n"); 209 210 bus_register_notifier(&i2c_bus_type, ®ulator_quirk_nb); 211 return 0; 212 213 err_free: 214 iounmap(irqc); 215 err_mem: 216 list_for_each_entry_safe(pos, tmp, &quirk_list, list) { 217 list_del(&pos->list); 218 kfree(pos); 219 } 220 221 return ret; 222 } 223 224 arch_initcall(rcar_gen2_regulator_quirk); 225