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