linux/drivers/pinctrl/meson/pinctrl-meson8-pmx.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * First generation of pinmux driver for Amlogic Meson SoCs
   4 *
   5 * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
   6 * Copyright (C) 2017 Jerome Brunet  <jbrunet@baylibre.com>
   7 */
   8
   9/* For this first generation of pinctrl driver every pinmux group can be
  10 * enabled by a specific bit in the first register range. When all groups for
  11 * a given pin are disabled the pin acts as a GPIO.
  12 */
  13#include <linux/device.h>
  14#include <linux/regmap.h>
  15#include <linux/pinctrl/pinctrl.h>
  16#include <linux/pinctrl/pinmux.h>
  17
  18#include "pinctrl-meson.h"
  19#include "pinctrl-meson8-pmx.h"
  20
  21/**
  22 * meson8_pmx_disable_other_groups() - disable other groups using a given pin
  23 *
  24 * @pc:         meson pin controller device
  25 * @pin:        number of the pin
  26 * @sel_group:  index of the selected group, or -1 if none
  27 *
  28 * The function disables all pinmux groups using a pin except the
  29 * selected one. If @sel_group is -1 all groups are disabled, leaving
  30 * the pin in GPIO mode.
  31 */
  32static void meson8_pmx_disable_other_groups(struct meson_pinctrl *pc,
  33                                            unsigned int pin, int sel_group)
  34{
  35        struct meson_pmx_group *group;
  36        struct meson8_pmx_data *pmx_data;
  37        int i, j;
  38
  39        for (i = 0; i < pc->data->num_groups; i++) {
  40                group = &pc->data->groups[i];
  41                pmx_data = (struct meson8_pmx_data *)group->data;
  42                if (pmx_data->is_gpio || i == sel_group)
  43                        continue;
  44
  45                for (j = 0; j < group->num_pins; j++) {
  46                        if (group->pins[j] == pin) {
  47                                /* We have found a group using the pin */
  48                                regmap_update_bits(pc->reg_mux,
  49                                                   pmx_data->reg * 4,
  50                                                   BIT(pmx_data->bit), 0);
  51                        }
  52                }
  53        }
  54}
  55
  56static int meson8_pmx_set_mux(struct pinctrl_dev *pcdev, unsigned func_num,
  57                              unsigned group_num)
  58{
  59        struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
  60        struct meson_pmx_func *func = &pc->data->funcs[func_num];
  61        struct meson_pmx_group *group = &pc->data->groups[group_num];
  62        struct meson8_pmx_data *pmx_data =
  63                (struct meson8_pmx_data *)group->data;
  64        int i, ret = 0;
  65
  66        dev_dbg(pc->dev, "enable function %s, group %s\n", func->name,
  67                group->name);
  68
  69        /*
  70         * Disable groups using the same pin.
  71         * The selected group is not disabled to avoid glitches.
  72         */
  73        for (i = 0; i < group->num_pins; i++)
  74                meson8_pmx_disable_other_groups(pc, group->pins[i], group_num);
  75
  76        /* Function 0 (GPIO) doesn't need any additional setting */
  77        if (func_num)
  78                ret = regmap_update_bits(pc->reg_mux, pmx_data->reg * 4,
  79                                         BIT(pmx_data->bit),
  80                                         BIT(pmx_data->bit));
  81
  82        return ret;
  83}
  84
  85static int meson8_pmx_request_gpio(struct pinctrl_dev *pcdev,
  86                                   struct pinctrl_gpio_range *range,
  87                                   unsigned offset)
  88{
  89        struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
  90
  91        meson8_pmx_disable_other_groups(pc, offset, -1);
  92
  93        return 0;
  94}
  95
  96const struct pinmux_ops meson8_pmx_ops = {
  97        .set_mux = meson8_pmx_set_mux,
  98        .get_functions_count = meson_pmx_get_funcs_count,
  99        .get_function_name = meson_pmx_get_func_name,
 100        .get_function_groups = meson_pmx_get_groups,
 101        .gpio_request_enable = meson8_pmx_request_gpio,
 102};
 103EXPORT_SYMBOL_GPL(meson8_pmx_ops);
 104MODULE_LICENSE("GPL v2");
 105