drivers/pinctrl/meson/pinctrl-meson8-pmx.c

   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  */
  32 static 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
  56 static 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
  85 static 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
  96 const 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 };
 103 EXPORT_SYMBOL_GPL(meson8_pmx_ops);
 104 MODULE_LICENSE("GPL v2");