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

   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/notifier.h>
  27 #include <linux/of.h>
  28 #include <linux/mfd/da9063/registers.h>
  29
  30
  31 #define IRQC_BASE               0xe61c0000
  32 #define IRQC_MONITOR            0x104   /* IRQn Signal Level Monitor Register */
  33
  34 #define REGULATOR_IRQ_MASK      BIT(2)  /* IRQ2, active low */
  35
  36 /* start of DA9210 System Control and Event Registers */
  37 #define DA9210_REG_MASK_A               0x54
  38
  39 static void __iomem *irqc;
  40
  41 /* first byte sets the memory pointer, following are consecutive reg values */
  42 static u8 da9063_irq_clr[] = { DA9063_REG_IRQ_MASK_A, 0xff, 0xff, 0xff, 0xff };
  43 static u8 da9210_irq_clr[] = { DA9210_REG_MASK_A, 0xff, 0xff };
  44
  45 static struct i2c_msg da9xxx_msgs[3] = {
  46         {
  47                 .addr = 0x58,
  48                 .len = ARRAY_SIZE(da9063_irq_clr),
  49                 .buf = da9063_irq_clr,
  50         }, {
  51                 .addr = 0x68,
  52                 .len = ARRAY_SIZE(da9210_irq_clr),
  53                 .buf = da9210_irq_clr,
  54         }, {
  55                 .addr = 0x70,
  56                 .len = ARRAY_SIZE(da9210_irq_clr),
  57                 .buf = da9210_irq_clr,
  58         },
  59 };
  60
  61 static int regulator_quirk_notify(struct notifier_block *nb,
  62                                   unsigned long action, void *data)
  63 {
  64         struct device *dev = data;
  65         struct i2c_client *client;
  66         static bool done;
  67         u32 mon;
  68
  69         if (done)
  70                 return 0;
  71
  72         mon = ioread32(irqc + IRQC_MONITOR);
  73         dev_dbg(dev, "%s: %ld, IRQC_MONITOR = 0x%x\n", __func__, action, mon);
  74         if (mon & REGULATOR_IRQ_MASK)
  75                 goto remove;
  76
  77         if (action != BUS_NOTIFY_ADD_DEVICE || dev->type == &i2c_adapter_type)
  78                 return 0;
  79
  80         client = to_i2c_client(dev);
  81         dev_dbg(dev, "Detected %s\n", client->name);
  82
  83         if ((client->addr == 0x58 && !strcmp(client->name, "da9063")) ||
  84             (client->addr == 0x68 && !strcmp(client->name, "da9210")) ||
  85             (client->addr == 0x70 && !strcmp(client->name, "da9210"))) {
  86                 int ret, len;
  87
  88                 /* There are two DA9210 on Stout, one on the other boards. */
  89                 len = of_machine_is_compatible("renesas,stout") ? 3 : 2;
  90
  91                 dev_info(&client->dev, "clearing da9063/da9210 interrupts\n");
  92                 ret = i2c_transfer(client->adapter, da9xxx_msgs, len);
  93                 if (ret != len)
  94                         dev_err(&client->dev, "i2c error %d\n", ret);
  95         }
  96
  97         mon = ioread32(irqc + IRQC_MONITOR);
  98         if (mon & REGULATOR_IRQ_MASK)
  99                 goto remove;
 100
 101         return 0;
 102
 103 remove:
 104         dev_info(dev, "IRQ2 is not asserted, removing quirk\n");
 105
 106         done = true;
 107         iounmap(irqc);
 108         return 0;
 109 }
 110
 111 static struct notifier_block regulator_quirk_nb = {
 112         .notifier_call = regulator_quirk_notify
 113 };
 114
 115 static int __init rcar_gen2_regulator_quirk(void)
 116 {
 117         u32 mon;
 118
 119         if (!of_machine_is_compatible("renesas,koelsch") &&
 120             !of_machine_is_compatible("renesas,lager") &&
 121             !of_machine_is_compatible("renesas,stout") &&
 122             !of_machine_is_compatible("renesas,gose"))
 123                 return -ENODEV;
 124
 125         irqc = ioremap(IRQC_BASE, PAGE_SIZE);
 126         if (!irqc)
 127                 return -ENOMEM;
 128
 129         mon = ioread32(irqc + IRQC_MONITOR);
 130         if (mon & REGULATOR_IRQ_MASK) {
 131                 pr_debug("%s: IRQ2 is not asserted, not installing quirk\n",
 132                          __func__);
 133                 iounmap(irqc);
 134                 return 0;
 135         }
 136
 137         pr_info("IRQ2 is asserted, installing da9063/da9210 regulator quirk\n");
 138
 139         bus_register_notifier(&i2c_bus_type, &regulator_quirk_nb);
 140         return 0;
 141 }
 142
 143 arch_initcall(rcar_gen2_regulator_quirk);