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 }; 109