arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c

   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         {},
  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                         break;
 159
 160                 ret = of_property_read_u32(np, "reg", &addr);
 161                 if (ret)        /* Skip invalid entry and continue */
 162                         continue;
 163
 164                 quirk = kzalloc(sizeof(*quirk), GFP_KERNEL);
 165                 if (!quirk) {
 166                         ret = -ENOMEM;
 167                         goto err_mem;
 168                 }
 169
 170                 argsa = &quirk->irq_args;
 171                 memcpy(&quirk->i2c_msg, id->data, sizeof(quirk->i2c_msg));
 172
 173                 quirk->id = id;
 174                 quirk->np = np;
 175                 quirk->i2c_msg.addr = addr;
 176
 177                 ret = of_irq_parse_one(np, 0, argsa);
 178                 if (ret) {      /* Skip invalid entry and continue */
 179                         kfree(quirk);
 180                         continue;
 181                 }
 182
 183                 list_for_each_entry(pos, &quirk_list, list) {
 184                         argsb = &pos->irq_args;
 185
 186                         if (argsa->args_count != argsb->args_count)
 187                                 continue;
 188
 189                         ret = memcmp(argsa->args, argsb->args,
 190                                      argsa->args_count *
 191                                      sizeof(argsa->args[0]));
 192                         if (!ret) {
 193                                 pos->shared = true;
 194                                 quirk->shared = true;
 195                         }
 196                 }
 197
 198                 list_add_tail(&quirk->list, &quirk_list);
 199         }
 200
 201         irqc = ioremap(IRQC_BASE, PAGE_SIZE);
 202         if (!irqc) {
 203                 ret = -ENOMEM;
 204                 goto err_mem;
 205         }
 206
 207         mon = ioread32(irqc + IRQC_MONITOR);
 208         if (mon & REGULATOR_IRQ_MASK) {
 209                 pr_debug("%s: IRQ2 is not asserted, not installing quirk\n",
 210                          __func__);
 211                 ret = 0;
 212                 goto err_free;
 213         }
 214
 215         pr_info("IRQ2 is asserted, installing regulator quirk\n");
 216
 217         bus_register_notifier(&i2c_bus_type, &regulator_quirk_nb);
 218         return 0;
 219
 220 err_free:
 221         iounmap(irqc);
 222 err_mem:
 223         list_for_each_entry_safe(pos, tmp, &quirk_list, list) {
 224                 list_del(&pos->list);
 225                 kfree(pos);
 226         }
 227
 228         return ret;
 229 }
 230
 231 arch_initcall(rcar_gen2_regulator_quirk);