target/linux/bmips/patches-5.10/003-v5.12-reset-add-BCM6345-reset-controller-driver.patch

   1 From aac025437f14c1647dc6054b95daeebed34f6971 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?=C3=81lvaro=20Fern=C3=A1ndez=20Rojas?= <noltari@gmail.com>
   3 Date: Wed, 17 Jun 2020 12:50:35 +0200
   4 Subject: [PATCH 3/9] reset: add BCM6345 reset controller driver
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Add support for resetting blocks through the Linux reset controller
  10 subsystem for BCM63xx SoCs.
  11
  12 Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
  13 Reviewed-by: Florian Fainelli <F.fainelli@gmail.com>
  14 Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
  15 Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
  16 ---
  17  drivers/reset/Kconfig         |   7 ++
  18  drivers/reset/Makefile        |   1 +
  19  drivers/reset/reset-bcm6345.c | 135 ++++++++++++++++++++++++++++++++++
  20  3 files changed, 143 insertions(+)
  21  create mode 100644 drivers/reset/reset-bcm6345.c
  22
  23 --- a/drivers/reset/Kconfig
  24 +++ b/drivers/reset/Kconfig
  25 @@ -35,6 +35,13 @@ config RESET_AXS10X
  26         help
  27           This enables the reset controller driver for AXS10x.
  28
  29 +config RESET_BCM6345
  30 +       bool "BCM6345 Reset Controller"
  31 +       depends on BMIPS_GENERIC || COMPILE_TEST
  32 +       default BMIPS_GENERIC
  33 +       help
  34 +         This enables the reset controller driver for BCM6345 SoCs.
  35 +
  36  config RESET_BERLIN
  37         bool "Berlin Reset Driver" if COMPILE_TEST
  38         default ARCH_BERLIN
  39 --- a/drivers/reset/Makefile
  40 +++ b/drivers/reset/Makefile
  41 @@ -6,6 +6,7 @@ obj-$(CONFIG_ARCH_TEGRA) += tegra/
  42  obj-$(CONFIG_RESET_A10SR) += reset-a10sr.o
  43  obj-$(CONFIG_RESET_ATH79) += reset-ath79.o
  44  obj-$(CONFIG_RESET_AXS10X) += reset-axs10x.o
  45 +obj-$(CONFIG_RESET_BCM6345) += reset-bcm6345.o
  46  obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o
  47  obj-$(CONFIG_RESET_BRCMSTB) += reset-brcmstb.o
  48  obj-$(CONFIG_RESET_BRCMSTB_RESCAL) += reset-brcmstb-rescal.o
  49 --- /dev/null
  50 +++ b/drivers/reset/reset-bcm6345.c
  51 @@ -0,0 +1,135 @@
  52 +// SPDX-License-Identifier: GPL-2.0-or-later
  53 +/*
  54 + * BCM6345 Reset Controller Driver
  55 + *
  56 + * Copyright (C) 2020 Álvaro Fernández Rojas <noltari@gmail.com>
  57 + */
  58 +
  59 +#include <linux/delay.h>
  60 +#include <linux/init.h>
  61 +#include <linux/io.h>
  62 +#include <linux/mod_devicetable.h>
  63 +#include <linux/platform_device.h>
  64 +#include <linux/reset-controller.h>
  65 +
  66 +#define BCM6345_RESET_NUM              32
  67 +#define BCM6345_RESET_SLEEP_MIN_US     10000
  68 +#define BCM6345_RESET_SLEEP_MAX_US     20000
  69 +
  70 +struct bcm6345_reset {
  71 +       struct reset_controller_dev rcdev;
  72 +       void __iomem *base;
  73 +       spinlock_t lock;
  74 +};
  75 +
  76 +static inline struct bcm6345_reset *
  77 +to_bcm6345_reset(struct reset_controller_dev *rcdev)
  78 +{
  79 +       return container_of(rcdev, struct bcm6345_reset, rcdev);
  80 +}
  81 +
  82 +static int bcm6345_reset_update(struct reset_controller_dev *rcdev,
  83 +                               unsigned long id, bool assert)
  84 +{
  85 +       struct bcm6345_reset *bcm6345_reset = to_bcm6345_reset(rcdev);
  86 +       unsigned long flags;
  87 +       uint32_t val;
  88 +
  89 +       spin_lock_irqsave(&bcm6345_reset->lock, flags);
  90 +       val = __raw_readl(bcm6345_reset->base);
  91 +       if (assert)
  92 +               val &= ~BIT(id);
  93 +       else
  94 +               val |= BIT(id);
  95 +       __raw_writel(val, bcm6345_reset->base);
  96 +       spin_unlock_irqrestore(&bcm6345_reset->lock, flags);
  97 +
  98 +       return 0;
  99 +}
 100 +
 101 +static int bcm6345_reset_assert(struct reset_controller_dev *rcdev,
 102 +                               unsigned long id)
 103 +{
 104 +       return bcm6345_reset_update(rcdev, id, true);
 105 +}
 106 +
 107 +static int bcm6345_reset_deassert(struct reset_controller_dev *rcdev,
 108 +                                 unsigned long id)
 109 +{
 110 +       return bcm6345_reset_update(rcdev, id, false);
 111 +}
 112 +
 113 +static int bcm6345_reset_reset(struct reset_controller_dev *rcdev,
 114 +                              unsigned long id)
 115 +{
 116 +       bcm6345_reset_update(rcdev, id, true);
 117 +       usleep_range(BCM6345_RESET_SLEEP_MIN_US,
 118 +                    BCM6345_RESET_SLEEP_MAX_US);
 119 +
 120 +       bcm6345_reset_update(rcdev, id, false);
 121 +       /*
 122 +        * Ensure component is taken out reset state by sleeping also after
 123 +        * deasserting the reset. Otherwise, the component may not be ready
 124 +        * for operation.
 125 +        */
 126 +       usleep_range(BCM6345_RESET_SLEEP_MIN_US,
 127 +                    BCM6345_RESET_SLEEP_MAX_US);
 128 +
 129 +       return 0;
 130 +}
 131 +
 132 +static int bcm6345_reset_status(struct reset_controller_dev *rcdev,
 133 +                               unsigned long id)
 134 +{
 135 +       struct bcm6345_reset *bcm6345_reset = to_bcm6345_reset(rcdev);
 136 +
 137 +       return !(__raw_readl(bcm6345_reset->base) & BIT(id));
 138 +}
 139 +
 140 +static struct reset_control_ops bcm6345_reset_ops = {
 141 +       .assert = bcm6345_reset_assert,
 142 +       .deassert = bcm6345_reset_deassert,
 143 +       .reset = bcm6345_reset_reset,
 144 +       .status = bcm6345_reset_status,
 145 +};
 146 +
 147 +static int bcm6345_reset_probe(struct platform_device *pdev)
 148 +{
 149 +       struct bcm6345_reset *bcm6345_reset;
 150 +
 151 +       bcm6345_reset = devm_kzalloc(&pdev->dev,
 152 +                                    sizeof(*bcm6345_reset), GFP_KERNEL);
 153 +       if (!bcm6345_reset)
 154 +               return -ENOMEM;
 155 +
 156 +       platform_set_drvdata(pdev, bcm6345_reset);
 157 +
 158 +       bcm6345_reset->base = devm_platform_ioremap_resource(pdev, 0);
 159 +       if (IS_ERR(bcm6345_reset->base))
 160 +               return PTR_ERR(bcm6345_reset->base);
 161 +
 162 +       spin_lock_init(&bcm6345_reset->lock);
 163 +       bcm6345_reset->rcdev.ops = &bcm6345_reset_ops;
 164 +       bcm6345_reset->rcdev.owner = THIS_MODULE;
 165 +       bcm6345_reset->rcdev.of_node = pdev->dev.of_node;
 166 +       bcm6345_reset->rcdev.of_reset_n_cells = 1;
 167 +       bcm6345_reset->rcdev.nr_resets = BCM6345_RESET_NUM;
 168 +
 169 +       return devm_reset_controller_register(&pdev->dev,
 170 +                                             &bcm6345_reset->rcdev);
 171 +}
 172 +
 173 +static const struct of_device_id bcm6345_reset_of_match[] = {
 174 +       { .compatible = "brcm,bcm6345-reset" },
 175 +       { /* sentinel */ },
 176 +};
 177 +
 178 +static struct platform_driver bcm6345_reset_driver = {
 179 +       .probe = bcm6345_reset_probe,
 180 +       .driver = {
 181 +               .name = "bcm6345-reset",
 182 +               .of_match_table = bcm6345_reset_of_match,
 183 +               .suppress_bind_attrs = true,
 184 +       },
 185 +};
 186 +builtin_platform_driver(bcm6345_reset_driver);