1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * R-Car Generation 2 da9063(L)/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 device_node *np; 44 struct of_phandle_args irq_args; 45 struct i2c_msg i2c_msg; 46 bool shared; /* IRQ line is shared */ 47 }; 48 49 static LIST_HEAD(quirk_list); 50 static void __iomem *irqc; 51 52 /* first byte sets the memory pointer, following are consecutive reg values */ 53 static u8 da9063_irq_clr[] = { DA9063_REG_IRQ_MASK_A, 0xff, 0xff, 0xff, 0xff }; 54 static u8 da9210_irq_clr[] = { DA9210_REG_MASK_A, 0xff, 0xff }; 55 56 static struct i2c_msg da9063_msg = { 57 .len = ARRAY_SIZE(da9063_irq_clr), 58 .buf = da9063_irq_clr, 59 }; 60 61 static struct i2c_msg da9210_msg = { 62 .len = ARRAY_SIZE(da9210_irq_clr), 63 .buf = da9210_irq_clr, 64 }; 65 66 static const struct of_device_id rcar_gen2_quirk_match[] = { 67 { .compatible = "dlg,da9063", .data = &da9063_msg }, 68 { .compatible = "dlg,da9063l", .data = &da9063_msg }, 69 { .compatible = "dlg,da9210", .data = &da9210_msg }, 70 { /* sentinel */ } 71 }; 72 73 static int regulator_quirk_notify(struct notifier_block *nb, 74 unsigned long action, void *data) 75 { 76 struct regulator_quirk *pos, *tmp; 77 struct device *dev = data; 78 struct i2c_client *client; 79 static bool done; 80 int ret; 81 u32 mon; 82 83 if (done) 84 return 0; 85 86 mon = ioread32(irqc + IRQC_MONITOR); 87 dev_dbg(dev, "%s: %ld, IRQC_MONITOR = 0x%x\n", __func__, action, mon); 88 if (mon & REGULATOR_IRQ_MASK) 89 goto remove; 90 91 if (action != BUS_NOTIFY_ADD_DEVICE || dev->type == &i2c_adapter_type) 92 return 0; 93 94 client = to_i2c_client(dev); 95 dev_dbg(dev, "Detected %s\n", client->name); 96 97 /* 98 * Send message to all PMICs that share an IRQ line to deassert it. 99 * 100 * WARNING: This works only if all the PMICs are on the same I2C bus. 101 */ 102 list_for_each_entry(pos, &quirk_list, list) { 103 if (!pos->shared) 104 continue; 105 106 if (pos->np->parent != client->dev.parent->of_node) 107 continue; 108 109 dev_info(&client->dev, "clearing %s@0x%02x interrupts\n", 110 pos->id->compatible, pos->i2c_msg.addr); 111 112 ret = i2c_transfer(client->adapter, &pos->i2c_msg, 1); 113 if (ret != 1) 114 dev_err(&client->dev, "i2c error %d\n", ret); 115 } 116 117 mon = ioread32(irqc + IRQC_MONITOR); 118 if (mon & REGULATOR_IRQ_MASK) 119 goto remove; 120 121 return 0; 122 123 remove: 124 dev_info(dev, "IRQ2 is not asserted, removing quirk\n"); 125 126 list_for_each_entry_safe(pos, tmp, &quirk_list, list) { 127 list_del(&pos->list); 128 kfree(pos); 129 } 130 131 done = true; 132 iounmap(irqc); 133 return 0; 134 } 135 136 static struct notifier_block regulator_quirk_nb = { 137 .notifier_call = regulator_quirk_notify 138 }; 139 140 static int __init rcar_gen2_regulator_quirk(void) 141 { 142 struct regulator_quirk *quirk, *pos, *tmp; 143 struct of_phandle_args *argsa, *argsb; 144 const struct of_device_id *id; 145 struct device_node *np; 146 u32 mon, addr; 147 int ret; 148 149 if (!of_machine_is_compatible("renesas,koelsch") && 150 !of_machine_is_compatible("renesas,lager") && 151 !of_machine_is_compatible("renesas,porter") && 152 !of_machine_is_compatible("renesas,stout") && 153 !of_machine_is_compatible("renesas,gose")) 154 return -ENODEV; 155 156 for_each_matching_node_and_match(np, rcar_gen2_quirk_match, &id) { 157 if (!of_device_is_available(np)) { 158 of_node_put(np); 159 break; 160 } 161 162 ret = of_property_read_u32(np, "reg", &addr); 163 if (ret) /* Skip invalid entry and continue */ 164 continue; 165 166 quirk = kzalloc(sizeof(*quirk), GFP_KERNEL); 167 if (!quirk) { 168 ret = -ENOMEM; 169 of_node_put(np); 170 goto err_mem; 171 } 172 173 argsa = &quirk->irq_args; 174 memcpy(&quirk->i2c_msg, id->data, sizeof(quirk->i2c_msg)); 175 176 quirk->id = id; 177 quirk->np = np; 178 quirk->i2c_msg.addr = addr; 179 180 ret = of_irq_parse_one(np, 0, argsa); 181 if (ret) { /* Skip invalid entry and continue */ 182 kfree(quirk); 183 continue; 184 } 185 186 list_for_each_entry(pos, &quirk_list, list) { 187 argsb = &pos->irq_args; 188 189 if (argsa->args_count != argsb->args_count) 190 continue; 191 192 ret = memcmp(argsa->args, argsb->args, 193 argsa->args_count * 194 sizeof(argsa->args[0])); 195 if (!ret) { 196 pos->shared = true; 197 quirk->shared = true; 198 } 199 } 200 201 list_add_tail(&quirk->list, &quirk_list); 202 } 203 204 irqc = ioremap(IRQC_BASE, PAGE_SIZE); 205 if (!irqc) { 206 ret = -ENOMEM; 207 goto err_mem; 208 } 209 210 mon = ioread32(irqc + IRQC_MONITOR); 211 if (mon & REGULATOR_IRQ_MASK) { 212 pr_debug("%s: IRQ2 is not asserted, not installing quirk\n", 213 __func__); 214 ret = 0; 215 goto err_free; 216 } 217 218 pr_info("IRQ2 is asserted, installing regulator quirk\n"); 219 220 bus_register_notifier(&i2c_bus_type, ®ulator_quirk_nb); 221 return 0; 222 223 err_free: 224 iounmap(irqc); 225 err_mem: 226 list_for_each_entry_safe(pos, tmp, &quirk_list, list) { 227 list_del(&pos->list); 228 kfree(pos); 229 } 230 231 return ret; 232 } 233 234 arch_initcall(rcar_gen2_regulator_quirk); 235