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 */
meson8_pmx_disable_other_groups(struct meson_pinctrl * pc,unsigned int pin,int sel_group)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
meson8_pmx_set_mux(struct pinctrl_dev * pcdev,unsigned func_num,unsigned group_num)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
meson8_pmx_request_gpio(struct pinctrl_dev * pcdev,struct pinctrl_gpio_range * range,unsigned offset)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");
105