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

   1 /*
   2  * First generation of pinmux driver for Amlogic Meson SoCs
   3  *
   4  * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
   5  * Copyright (C) 2017 Jerome Brunet  <jbrunet@baylibre.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  *
  11  * You should have received a copy of the GNU General Public License
  12  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  13  */
  14
  15 /* For this first generation of pinctrl driver every pinmux group can be
  16  * enabled by a specific bit in the first register range. When all groups for
  17  * a given pin are disabled the pin acts as a GPIO.
  18  */
  19 #include <linux/device.h>
  20 #include <linux/regmap.h>
  21 #include <linux/pinctrl/pinctrl.h>
  22 #include <linux/pinctrl/pinmux.h>
  23
  24 #include "pinctrl-meson.h"
  25 #include "pinctrl-meson8-pmx.h"
  26
  27 /**
  28  * meson8_pmx_disable_other_groups() - disable other groups using a given pin
  29  *
  30  * @pc:         meson pin controller device
  31  * @pin:        number of the pin
  32  * @sel_group:  index of the selected group, or -1 if none
  33  *
  34  * The function disables all pinmux groups using a pin except the
  35  * selected one. If @sel_group is -1 all groups are disabled, leaving
  36  * the pin in GPIO mode.
  37  */
  38 static void meson8_pmx_disable_other_groups(struct meson_pinctrl *pc,
  39                                             unsigned int pin, int sel_group)
  40 {
  41         struct meson_pmx_group *group;
  42         struct meson8_pmx_data *pmx_data;
  43         int i, j;
  44
  45         for (i = 0; i < pc->data->num_groups; i++) {
  46                 group = &pc->data->groups[i];
  47                 pmx_data = (struct meson8_pmx_data *)group->data;
  48                 if (pmx_data->is_gpio || i == sel_group)
  49                         continue;
  50
  51                 for (j = 0; j < group->num_pins; j++) {
  52                         if (group->pins[j] == pin) {
  53                                 /* We have found a group using the pin */
  54                                 regmap_update_bits(pc->reg_mux,
  55                                                    pmx_data->reg * 4,
  56                                                    BIT(pmx_data->bit), 0);
  57                         }
  58                 }
  59         }
  60 }
  61
  62 static int meson8_pmx_set_mux(struct pinctrl_dev *pcdev, unsigned func_num,
  63                               unsigned group_num)
  64 {
  65         struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
  66         struct meson_pmx_func *func = &pc->data->funcs[func_num];
  67         struct meson_pmx_group *group = &pc->data->groups[group_num];
  68         struct meson8_pmx_data *pmx_data =
  69                 (struct meson8_pmx_data *)group->data;
  70         int i, ret = 0;
  71
  72         dev_dbg(pc->dev, "enable function %s, group %s\n", func->name,
  73                 group->name);
  74
  75         /*
  76          * Disable groups using the same pin.
  77          * The selected group is not disabled to avoid glitches.
  78          */
  79         for (i = 0; i < group->num_pins; i++)
  80                 meson8_pmx_disable_other_groups(pc, group->pins[i], group_num);
  81
  82         /* Function 0 (GPIO) doesn't need any additional setting */
  83         if (func_num)
  84                 ret = regmap_update_bits(pc->reg_mux, pmx_data->reg * 4,
  85                                          BIT(pmx_data->bit),
  86                                          BIT(pmx_data->bit));
  87
  88         return ret;
  89 }
  90
  91 static int meson8_pmx_request_gpio(struct pinctrl_dev *pcdev,
  92                                    struct pinctrl_gpio_range *range,
  93                                    unsigned offset)
  94 {
  95         struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
  96
  97         meson8_pmx_disable_other_groups(pc, offset, -1);
  98
  99         return 0;
 100 }
 101
 102 const struct pinmux_ops meson8_pmx_ops = {
 103         .set_mux = meson8_pmx_set_mux,
 104         .get_functions_count = meson_pmx_get_funcs_count,
 105         .get_function_name = meson_pmx_get_func_name,
 106         .get_function_groups = meson_pmx_get_groups,
 107         .gpio_request_enable = meson8_pmx_request_gpio,
 108 };