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

   1 /*
   2  * R-Car Generation 2 da9063/da9210 regulator quirk
   3  *
   4  * The r8a7790/lager and r8a7791/koelsch development boards have da9063 and
   5  * da9210 regulators.  Both regulators have their interrupt request lines tied
   6  * 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 static void __iomem *irqc;
  45
  46 static const u8 da9063_mask_regs[] = {
  47         DA9063_REG_IRQ_MASK_A,
  48         DA9063_REG_IRQ_MASK_B,
  49         DA9063_REG_IRQ_MASK_C,
  50         DA9063_REG_IRQ_MASK_D,
  51 };
  52
  53 /* DA9210 System Control and Event Registers */
  54 #define DA9210_REG_MASK_A               0x54
  55 #define DA9210_REG_MASK_B               0x55
  56
  57 static const u8 da9210_mask_regs[] = {
  58         DA9210_REG_MASK_A,
  59         DA9210_REG_MASK_B,
  60 };
  61
  62 static void da9xxx_mask_irqs(struct i2c_client *client, const u8 regs[],
  63                              unsigned int nregs)
  64 {
  65         unsigned int i;
  66
  67         dev_info(&client->dev, "Masking %s interrupt sources\n", client->name);
  68
  69         for (i = 0; i < nregs; i++) {
  70                 int error = i2c_smbus_write_byte_data(client, regs[i], ~0);
  71                 if (error) {
  72                         dev_err(&client->dev, "i2c error %d\n", error);
  73                         return;
  74                 }
  75         }
  76 }
  77
  78 static int regulator_quirk_notify(struct notifier_block *nb,
  79                                   unsigned long action, void *data)
  80 {
  81         struct device *dev = data;
  82         struct i2c_client *client;
  83         u32 mon;
  84
  85         mon = ioread32(irqc + IRQC_MONITOR);
  86         dev_dbg(dev, "%s: %ld, IRQC_MONITOR = 0x%x\n", __func__, action, mon);
  87         if (mon & REGULATOR_IRQ_MASK)
  88                 goto remove;
  89
  90         if (action != BUS_NOTIFY_ADD_DEVICE || dev->type == &i2c_adapter_type)
  91                 return 0;
  92
  93         client = to_i2c_client(dev);
  94         dev_dbg(dev, "Detected %s\n", client->name);
  95
  96         if ((client->addr == 0x58 && !strcmp(client->name, "da9063")))
  97                 da9xxx_mask_irqs(client, da9063_mask_regs,
  98                                  ARRAY_SIZE(da9063_mask_regs));
  99         else if (client->addr == 0x68 && !strcmp(client->name, "da9210"))
 100                 da9xxx_mask_irqs(client, da9210_mask_regs,
 101                                  ARRAY_SIZE(da9210_mask_regs));
 102
 103         mon = ioread32(irqc + IRQC_MONITOR);
 104         if (mon & REGULATOR_IRQ_MASK)
 105                 goto remove;
 106
 107         return 0;
 108
 109 remove:
 110         dev_info(dev, "IRQ2 is not asserted, removing quirk\n");
 111
 112         bus_unregister_notifier(&i2c_bus_type, nb);
 113         iounmap(irqc);
 114         return 0;
 115 }
 116
 117 static struct notifier_block regulator_quirk_nb = {
 118         .notifier_call = regulator_quirk_notify
 119 };
 120
 121 static int __init rcar_gen2_regulator_quirk(void)
 122 {
 123         u32 mon;
 124
 125         if (!of_machine_is_compatible("renesas,koelsch") &&
 126             !of_machine_is_compatible("renesas,lager") &&
 127             !of_machine_is_compatible("renesas,gose"))
 128                 return -ENODEV;
 129
 130         irqc = ioremap(IRQC_BASE, PAGE_SIZE);
 131         if (!irqc)
 132                 return -ENOMEM;
 133
 134         mon = ioread32(irqc + IRQC_MONITOR);
 135         if (mon & REGULATOR_IRQ_MASK) {
 136                 pr_debug("%s: IRQ2 is not asserted, not installing quirk\n",
 137                          __func__);
 138                 iounmap(irqc);
 139                 return 0;
 140         }
 141
 142         pr_info("IRQ2 is asserted, installing da9063/da9210 regulator quirk\n");
 143
 144         bus_register_notifier(&i2c_bus_type, &regulator_quirk_nb);
 145         return 0;
 146 }
 147
 148 arch_initcall(rcar_gen2_regulator_quirk);