LXR uboot/drivers/mux/mmio.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * MMIO register bitfield-controlled multiplexer driver
   4 * Based on the linux mmio multiplexer driver
   5 *
   6 * Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de>
   7 * Copyright (C) 2019 Texas Instrument, Jean-jacques Hiblot <jjhiblot@ti.com>
   8 */
   9#include <common.h>
  10#include <dm.h>
  11#include <mux-internal.h>
  12#include <regmap.h>
  13#include <syscon.h>
  14#include <dm/device.h>
  15#include <dm/device_compat.h>
  16#include <dm/read.h>
  17#include <dm/devres.h>
  18#include <dt-bindings/mux/mux.h>
  19#include <linux/bitops.h>
  20
  21static int mux_mmio_set(struct mux_control *mux, int state)
  22{
  23        struct regmap_field **fields = dev_get_priv(mux->dev);
  24
  25        return regmap_field_write(fields[mux_control_get_index(mux)], state);
  26}
  27
  28static const struct mux_control_ops mux_mmio_ops = {
  29        .set = mux_mmio_set,
  30};
  31
  32static const struct udevice_id mmio_mux_of_match[] = {
  33        { .compatible = "mmio-mux" },
  34        { /* sentinel */ },
  35};
  36
  37static int mmio_mux_probe(struct udevice *dev)
  38{
  39        struct regmap_field **fields;
  40        struct mux_chip *mux_chip = dev_get_uclass_priv(dev);
  41        struct regmap *regmap;
  42        u32 *mux_reg_masks;
  43        u32 *idle_states;
  44        int num_fields;
  45        int ret;
  46        int i;
  47
  48        regmap = syscon_node_to_regmap(dev_ofnode(dev->parent));
  49        if (IS_ERR(regmap)) {
  50                ret = PTR_ERR(regmap);
  51                dev_err(dev, "failed to get regmap: %d\n", ret);
  52                return ret;
  53        }
  54
  55        num_fields = dev_read_size(dev, "mux-reg-masks");
  56        if (num_fields < 0)
  57                return log_msg_ret("mux-reg-masks missing", -EINVAL);
  58
  59        num_fields /= sizeof(u32);
  60        if (num_fields == 0 || num_fields % 2)
  61                ret = -EINVAL;
  62        num_fields = num_fields / 2;
  63
  64        ret = mux_alloc_controllers(dev, num_fields);
  65        if (ret < 0)
  66                return log_msg_ret("mux_alloc_controllers", ret);
  67
  68        fields = devm_kmalloc(dev, num_fields * sizeof(*fields), __GFP_ZERO);
  69        if (!fields)
  70                return -ENOMEM;
  71        dev->priv = fields;
  72
  73        mux_reg_masks = devm_kmalloc(dev, num_fields * 2 * sizeof(u32),
  74                                     __GFP_ZERO);
  75        if (!mux_reg_masks)
  76                return -ENOMEM;
  77
  78        ret = dev_read_u32_array(dev, "mux-reg-masks", mux_reg_masks,
  79                                 num_fields * 2);
  80        if (ret < 0)
  81                return log_msg_ret("mux-reg-masks read", ret);
  82
  83        idle_states = devm_kmalloc(dev, num_fields * sizeof(u32), __GFP_ZERO);
  84        if (!idle_states)
  85                return -ENOMEM;
  86
  87        ret = dev_read_u32_array(dev, "idle-states", idle_states, num_fields);
  88        if (ret < 0) {
  89                log_err("idle-states");
  90                devm_kfree(dev, idle_states);
  91                idle_states = NULL;
  92        }
  93
  94        for (i = 0; i < num_fields; i++) {
  95                struct mux_control *mux = &mux_chip->mux[i];
  96                struct reg_field field;
  97                u32 reg, mask;
  98                int bits;
  99
 100                reg = mux_reg_masks[2 * i];
 101                mask = mux_reg_masks[2 * i + 1];
 102
 103                field.reg = reg;
 104                field.msb = fls(mask) - 1;
 105                field.lsb = ffs(mask) - 1;
 106
 107                if (mask != GENMASK(field.msb, field.lsb))
 108                        return log_msg_ret("invalid mask", -EINVAL);
 109
 110                fields[i] = devm_regmap_field_alloc(dev, regmap, field);
 111                if (IS_ERR(fields[i])) {
 112                        ret = PTR_ERR(fields[i]);
 113                        return log_msg_ret("regmap_field_alloc", ret);
 114                }
 115
 116                bits = 1 + field.msb - field.lsb;
 117                mux->states = 1 << bits;
 118
 119                if (!idle_states)
 120                        continue;
 121
 122                if (idle_states[i] != MUX_IDLE_AS_IS &&
 123                    idle_states[i] >= mux->states)
 124                        return log_msg_ret("idle-states range", -EINVAL);
 125
 126                mux->idle_state = idle_states[i];
 127        }
 128
 129        devm_kfree(dev, mux_reg_masks);
 130        if (idle_states)
 131                devm_kfree(dev, idle_states);
 132
 133        return 0;
 134}
 135
 136U_BOOT_DRIVER(mmio_mux) = {
 137        .name = "mmio-mux",
 138        .id = UCLASS_MUX,
 139        .of_match = mmio_mux_of_match,
 140        .probe = mmio_mux_probe,
 141        .ops = &mux_mmio_ops,
 142};
 143